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- // SPDX-License-Identifier: GPL-2.0-or-later
- // SPI init/core code
- //
- // Copyright (C) 2005 David Brownell
- // Copyright (C) 2008 Secret Lab Technologies Ltd.
- #include <linux/kernel.h>
- #include <linux/device.h>
- #include <linux/init.h>
- #include <linux/cache.h>
- #include <linux/dma-mapping.h>
- #include <linux/dmaengine.h>
- #include <linux/mutex.h>
- #include <linux/of_device.h>
- #include <linux/of_irq.h>
- #include <linux/clk/clk-conf.h>
- #include <linux/slab.h>
- #include <linux/mod_devicetable.h>
- #include <linux/spi/spi.h>
- #include <linux/spi/spi-mem.h>
- #include <linux/of_gpio.h>
- #include <linux/gpio/consumer.h>
- #include <linux/pm_runtime.h>
- #include <linux/pm_domain.h>
- #include <linux/property.h>
- #include <linux/export.h>
- #include <linux/sched/rt.h>
- #include <uapi/linux/sched/types.h>
- #include <linux/delay.h>
- #include <linux/kthread.h>
- #include <linux/ioport.h>
- #include <linux/acpi.h>
- #include <linux/highmem.h>
- #include <linux/idr.h>
- #include <linux/platform_data/x86/apple.h>
- #define CREATE_TRACE_POINTS
- #include <trace/events/spi.h>
- EXPORT_TRACEPOINT_SYMBOL(spi_transfer_start);
- EXPORT_TRACEPOINT_SYMBOL(spi_transfer_stop);
- #include "internals.h"
- static DEFINE_IDR(spi_master_idr);
- static void spidev_release(struct device *dev)
- {
- struct spi_device *spi = to_spi_device(dev);
- spi_controller_put(spi->controller);
- kfree(spi->driver_override);
- kfree(spi);
- }
- static ssize_t
- modalias_show(struct device *dev, struct device_attribute *a, char *buf)
- {
- const struct spi_device *spi = to_spi_device(dev);
- int len;
- len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
- if (len != -ENODEV)
- return len;
- return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
- }
- static DEVICE_ATTR_RO(modalias);
- static ssize_t driver_override_store(struct device *dev,
- struct device_attribute *a,
- const char *buf, size_t count)
- {
- struct spi_device *spi = to_spi_device(dev);
- const char *end = memchr(buf, '\n', count);
- const size_t len = end ? end - buf : count;
- const char *driver_override, *old;
- /* We need to keep extra room for a newline when displaying value */
- if (len >= (PAGE_SIZE - 1))
- return -EINVAL;
- driver_override = kstrndup(buf, len, GFP_KERNEL);
- if (!driver_override)
- return -ENOMEM;
- device_lock(dev);
- old = spi->driver_override;
- if (len) {
- spi->driver_override = driver_override;
- } else {
- /* Empty string, disable driver override */
- spi->driver_override = NULL;
- kfree(driver_override);
- }
- device_unlock(dev);
- kfree(old);
- return count;
- }
- static ssize_t driver_override_show(struct device *dev,
- struct device_attribute *a, char *buf)
- {
- const struct spi_device *spi = to_spi_device(dev);
- ssize_t len;
- device_lock(dev);
- len = snprintf(buf, PAGE_SIZE, "%s\n", spi->driver_override ? : "");
- device_unlock(dev);
- return len;
- }
- static DEVICE_ATTR_RW(driver_override);
- #define SPI_STATISTICS_ATTRS(field, file) \
- static ssize_t spi_controller_##field##_show(struct device *dev, \
- struct device_attribute *attr, \
- char *buf) \
- { \
- struct spi_controller *ctlr = container_of(dev, \
- struct spi_controller, dev); \
- return spi_statistics_##field##_show(&ctlr->statistics, buf); \
- } \
- static struct device_attribute dev_attr_spi_controller_##field = { \
- .attr = { .name = file, .mode = 0444 }, \
- .show = spi_controller_##field##_show, \
- }; \
- static ssize_t spi_device_##field##_show(struct device *dev, \
- struct device_attribute *attr, \
- char *buf) \
- { \
- struct spi_device *spi = to_spi_device(dev); \
- return spi_statistics_##field##_show(&spi->statistics, buf); \
- } \
- static struct device_attribute dev_attr_spi_device_##field = { \
- .attr = { .name = file, .mode = 0444 }, \
- .show = spi_device_##field##_show, \
- }
- #define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \
- static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
- char *buf) \
- { \
- unsigned long flags; \
- ssize_t len; \
- spin_lock_irqsave(&stat->lock, flags); \
- len = sprintf(buf, format_string, stat->field); \
- spin_unlock_irqrestore(&stat->lock, flags); \
- return len; \
- } \
- SPI_STATISTICS_ATTRS(name, file)
- #define SPI_STATISTICS_SHOW(field, format_string) \
- SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
- field, format_string)
- SPI_STATISTICS_SHOW(messages, "%lu");
- SPI_STATISTICS_SHOW(transfers, "%lu");
- SPI_STATISTICS_SHOW(errors, "%lu");
- SPI_STATISTICS_SHOW(timedout, "%lu");
- SPI_STATISTICS_SHOW(spi_sync, "%lu");
- SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu");
- SPI_STATISTICS_SHOW(spi_async, "%lu");
- SPI_STATISTICS_SHOW(bytes, "%llu");
- SPI_STATISTICS_SHOW(bytes_rx, "%llu");
- SPI_STATISTICS_SHOW(bytes_tx, "%llu");
- #define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
- SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
- "transfer_bytes_histo_" number, \
- transfer_bytes_histo[index], "%lu")
- SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
- SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
- SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
- SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
- SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
- SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
- SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
- SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
- SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
- SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
- SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
- SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
- SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
- SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
- SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
- SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
- SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
- SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
- static struct attribute *spi_dev_attrs[] = {
- &dev_attr_modalias.attr,
- &dev_attr_driver_override.attr,
- NULL,
- };
- static const struct attribute_group spi_dev_group = {
- .attrs = spi_dev_attrs,
- };
- static struct attribute *spi_device_statistics_attrs[] = {
- &dev_attr_spi_device_messages.attr,
- &dev_attr_spi_device_transfers.attr,
- &dev_attr_spi_device_errors.attr,
- &dev_attr_spi_device_timedout.attr,
- &dev_attr_spi_device_spi_sync.attr,
- &dev_attr_spi_device_spi_sync_immediate.attr,
- &dev_attr_spi_device_spi_async.attr,
- &dev_attr_spi_device_bytes.attr,
- &dev_attr_spi_device_bytes_rx.attr,
- &dev_attr_spi_device_bytes_tx.attr,
- &dev_attr_spi_device_transfer_bytes_histo0.attr,
- &dev_attr_spi_device_transfer_bytes_histo1.attr,
- &dev_attr_spi_device_transfer_bytes_histo2.attr,
- &dev_attr_spi_device_transfer_bytes_histo3.attr,
- &dev_attr_spi_device_transfer_bytes_histo4.attr,
- &dev_attr_spi_device_transfer_bytes_histo5.attr,
- &dev_attr_spi_device_transfer_bytes_histo6.attr,
- &dev_attr_spi_device_transfer_bytes_histo7.attr,
- &dev_attr_spi_device_transfer_bytes_histo8.attr,
- &dev_attr_spi_device_transfer_bytes_histo9.attr,
- &dev_attr_spi_device_transfer_bytes_histo10.attr,
- &dev_attr_spi_device_transfer_bytes_histo11.attr,
- &dev_attr_spi_device_transfer_bytes_histo12.attr,
- &dev_attr_spi_device_transfer_bytes_histo13.attr,
- &dev_attr_spi_device_transfer_bytes_histo14.attr,
- &dev_attr_spi_device_transfer_bytes_histo15.attr,
- &dev_attr_spi_device_transfer_bytes_histo16.attr,
- &dev_attr_spi_device_transfers_split_maxsize.attr,
- NULL,
- };
- static const struct attribute_group spi_device_statistics_group = {
- .name = "statistics",
- .attrs = spi_device_statistics_attrs,
- };
- static const struct attribute_group *spi_dev_groups[] = {
- &spi_dev_group,
- &spi_device_statistics_group,
- NULL,
- };
- static struct attribute *spi_controller_statistics_attrs[] = {
- &dev_attr_spi_controller_messages.attr,
- &dev_attr_spi_controller_transfers.attr,
- &dev_attr_spi_controller_errors.attr,
- &dev_attr_spi_controller_timedout.attr,
- &dev_attr_spi_controller_spi_sync.attr,
- &dev_attr_spi_controller_spi_sync_immediate.attr,
- &dev_attr_spi_controller_spi_async.attr,
- &dev_attr_spi_controller_bytes.attr,
- &dev_attr_spi_controller_bytes_rx.attr,
- &dev_attr_spi_controller_bytes_tx.attr,
- &dev_attr_spi_controller_transfer_bytes_histo0.attr,
- &dev_attr_spi_controller_transfer_bytes_histo1.attr,
- &dev_attr_spi_controller_transfer_bytes_histo2.attr,
- &dev_attr_spi_controller_transfer_bytes_histo3.attr,
- &dev_attr_spi_controller_transfer_bytes_histo4.attr,
- &dev_attr_spi_controller_transfer_bytes_histo5.attr,
- &dev_attr_spi_controller_transfer_bytes_histo6.attr,
- &dev_attr_spi_controller_transfer_bytes_histo7.attr,
- &dev_attr_spi_controller_transfer_bytes_histo8.attr,
- &dev_attr_spi_controller_transfer_bytes_histo9.attr,
- &dev_attr_spi_controller_transfer_bytes_histo10.attr,
- &dev_attr_spi_controller_transfer_bytes_histo11.attr,
- &dev_attr_spi_controller_transfer_bytes_histo12.attr,
- &dev_attr_spi_controller_transfer_bytes_histo13.attr,
- &dev_attr_spi_controller_transfer_bytes_histo14.attr,
- &dev_attr_spi_controller_transfer_bytes_histo15.attr,
- &dev_attr_spi_controller_transfer_bytes_histo16.attr,
- &dev_attr_spi_controller_transfers_split_maxsize.attr,
- NULL,
- };
- static const struct attribute_group spi_controller_statistics_group = {
- .name = "statistics",
- .attrs = spi_controller_statistics_attrs,
- };
- static const struct attribute_group *spi_master_groups[] = {
- &spi_controller_statistics_group,
- NULL,
- };
- void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
- struct spi_transfer *xfer,
- struct spi_controller *ctlr)
- {
- unsigned long flags;
- int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
- if (l2len < 0)
- l2len = 0;
- spin_lock_irqsave(&stats->lock, flags);
- stats->transfers++;
- stats->transfer_bytes_histo[l2len]++;
- stats->bytes += xfer->len;
- if ((xfer->tx_buf) &&
- (xfer->tx_buf != ctlr->dummy_tx))
- stats->bytes_tx += xfer->len;
- if ((xfer->rx_buf) &&
- (xfer->rx_buf != ctlr->dummy_rx))
- stats->bytes_rx += xfer->len;
- spin_unlock_irqrestore(&stats->lock, flags);
- }
- EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats);
- /* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
- * and the sysfs version makes coldplug work too.
- */
- static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
- const struct spi_device *sdev)
- {
- while (id->name[0]) {
- if (!strcmp(sdev->modalias, id->name))
- return id;
- id++;
- }
- return NULL;
- }
- const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
- {
- const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
- return spi_match_id(sdrv->id_table, sdev);
- }
- EXPORT_SYMBOL_GPL(spi_get_device_id);
- static int spi_match_device(struct device *dev, struct device_driver *drv)
- {
- const struct spi_device *spi = to_spi_device(dev);
- const struct spi_driver *sdrv = to_spi_driver(drv);
- /* Check override first, and if set, only use the named driver */
- if (spi->driver_override)
- return strcmp(spi->driver_override, drv->name) == 0;
- /* Attempt an OF style match */
- if (of_driver_match_device(dev, drv))
- return 1;
- /* Then try ACPI */
- if (acpi_driver_match_device(dev, drv))
- return 1;
- if (sdrv->id_table)
- return !!spi_match_id(sdrv->id_table, spi);
- return strcmp(spi->modalias, drv->name) == 0;
- }
- static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
- {
- const struct spi_device *spi = to_spi_device(dev);
- int rc;
- rc = acpi_device_uevent_modalias(dev, env);
- if (rc != -ENODEV)
- return rc;
- return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
- }
- struct bus_type spi_bus_type = {
- .name = "spi",
- .dev_groups = spi_dev_groups,
- .match = spi_match_device,
- .uevent = spi_uevent,
- };
- EXPORT_SYMBOL_GPL(spi_bus_type);
- static int spi_drv_probe(struct device *dev)
- {
- const struct spi_driver *sdrv = to_spi_driver(dev->driver);
- struct spi_device *spi = to_spi_device(dev);
- int ret;
- ret = of_clk_set_defaults(dev->of_node, false);
- if (ret)
- return ret;
- if (dev->of_node) {
- spi->irq = of_irq_get(dev->of_node, 0);
- if (spi->irq == -EPROBE_DEFER)
- return -EPROBE_DEFER;
- if (spi->irq < 0)
- spi->irq = 0;
- }
- ret = dev_pm_domain_attach(dev, true);
- if (ret)
- return ret;
- if (sdrv->probe) {
- ret = sdrv->probe(spi);
- if (ret)
- dev_pm_domain_detach(dev, true);
- }
- return ret;
- }
- static int spi_drv_remove(struct device *dev)
- {
- const struct spi_driver *sdrv = to_spi_driver(dev->driver);
- int ret = 0;
- if (sdrv->remove)
- ret = sdrv->remove(to_spi_device(dev));
- dev_pm_domain_detach(dev, true);
- return ret;
- }
- static void spi_drv_shutdown(struct device *dev)
- {
- const struct spi_driver *sdrv = to_spi_driver(dev->driver);
- sdrv->shutdown(to_spi_device(dev));
- }
- /**
- * __spi_register_driver - register a SPI driver
- * @owner: owner module of the driver to register
- * @sdrv: the driver to register
- * Context: can sleep
- *
- * Return: zero on success, else a negative error code.
- */
- int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
- {
- sdrv->driver.owner = owner;
- sdrv->driver.bus = &spi_bus_type;
- sdrv->driver.probe = spi_drv_probe;
- sdrv->driver.remove = spi_drv_remove;
- if (sdrv->shutdown)
- sdrv->driver.shutdown = spi_drv_shutdown;
- return driver_register(&sdrv->driver);
- }
- EXPORT_SYMBOL_GPL(__spi_register_driver);
- /*-------------------------------------------------------------------------*/
- /* SPI devices should normally not be created by SPI device drivers; that
- * would make them board-specific. Similarly with SPI controller drivers.
- * Device registration normally goes into like arch/.../mach.../board-YYY.c
- * with other readonly (flashable) information about mainboard devices.
- */
- struct boardinfo {
- struct list_head list;
- struct spi_board_info board_info;
- };
- static LIST_HEAD(board_list);
- static LIST_HEAD(spi_controller_list);
- /*
- * Used to protect add/del operation for board_info list and
- * spi_controller list, and their matching process
- * also used to protect object of type struct idr
- */
- static DEFINE_MUTEX(board_lock);
- /*
- * Prevents addition of devices with same chip select and
- * addition of devices below an unregistering controller.
- */
- static DEFINE_MUTEX(spi_add_lock);
- /**
- * spi_alloc_device - Allocate a new SPI device
- * @ctlr: Controller to which device is connected
- * Context: can sleep
- *
- * Allows a driver to allocate and initialize a spi_device without
- * registering it immediately. This allows a driver to directly
- * fill the spi_device with device parameters before calling
- * spi_add_device() on it.
- *
- * Caller is responsible to call spi_add_device() on the returned
- * spi_device structure to add it to the SPI controller. If the caller
- * needs to discard the spi_device without adding it, then it should
- * call spi_dev_put() on it.
- *
- * Return: a pointer to the new device, or NULL.
- */
- struct spi_device *spi_alloc_device(struct spi_controller *ctlr)
- {
- struct spi_device *spi;
- if (!spi_controller_get(ctlr))
- return NULL;
- spi = kzalloc(sizeof(*spi), GFP_KERNEL);
- if (!spi) {
- spi_controller_put(ctlr);
- return NULL;
- }
- spi->master = spi->controller = ctlr;
- spi->dev.parent = &ctlr->dev;
- spi->dev.bus = &spi_bus_type;
- spi->dev.release = spidev_release;
- spi->cs_gpio = -ENOENT;
- spi->mode = ctlr->buswidth_override_bits;
- spin_lock_init(&spi->statistics.lock);
- device_initialize(&spi->dev);
- return spi;
- }
- EXPORT_SYMBOL_GPL(spi_alloc_device);
- static void spi_dev_set_name(struct spi_device *spi)
- {
- struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
- if (adev) {
- dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
- return;
- }
- dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev),
- spi->chip_select);
- }
- static int spi_dev_check(struct device *dev, void *data)
- {
- struct spi_device *spi = to_spi_device(dev);
- struct spi_device *new_spi = data;
- if (spi->controller == new_spi->controller &&
- spi->chip_select == new_spi->chip_select)
- return -EBUSY;
- return 0;
- }
- static void spi_cleanup(struct spi_device *spi)
- {
- if (spi->controller->cleanup)
- spi->controller->cleanup(spi);
- }
- /**
- * spi_add_device - Add spi_device allocated with spi_alloc_device
- * @spi: spi_device to register
- *
- * Companion function to spi_alloc_device. Devices allocated with
- * spi_alloc_device can be added onto the spi bus with this function.
- *
- * Return: 0 on success; negative errno on failure
- */
- int spi_add_device(struct spi_device *spi)
- {
- struct spi_controller *ctlr = spi->controller;
- struct device *dev = ctlr->dev.parent;
- int status;
- /* Chipselects are numbered 0..max; validate. */
- if (spi->chip_select >= ctlr->num_chipselect) {
- dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
- ctlr->num_chipselect);
- return -EINVAL;
- }
- /* Set the bus ID string */
- spi_dev_set_name(spi);
- /* We need to make sure there's no other device with this
- * chipselect **BEFORE** we call setup(), else we'll trash
- * its configuration. Lock against concurrent add() calls.
- */
- mutex_lock(&spi_add_lock);
- status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
- if (status) {
- dev_err(dev, "chipselect %d already in use\n",
- spi->chip_select);
- goto done;
- }
- /* Controller may unregister concurrently */
- if (IS_ENABLED(CONFIG_SPI_DYNAMIC) &&
- !device_is_registered(&ctlr->dev)) {
- status = -ENODEV;
- goto done;
- }
- /* Descriptors take precedence */
- if (ctlr->cs_gpiods)
- spi->cs_gpiod = ctlr->cs_gpiods[spi->chip_select];
- else if (ctlr->cs_gpios)
- spi->cs_gpio = ctlr->cs_gpios[spi->chip_select];
- /* Drivers may modify this initial i/o setup, but will
- * normally rely on the device being setup. Devices
- * using SPI_CS_HIGH can't coexist well otherwise...
- */
- status = spi_setup(spi);
- if (status < 0) {
- dev_err(dev, "can't setup %s, status %d\n",
- dev_name(&spi->dev), status);
- goto done;
- }
- /* Device may be bound to an active driver when this returns */
- status = device_add(&spi->dev);
- if (status < 0) {
- dev_err(dev, "can't add %s, status %d\n",
- dev_name(&spi->dev), status);
- spi_cleanup(spi);
- } else {
- dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
- }
- done:
- mutex_unlock(&spi_add_lock);
- return status;
- }
- EXPORT_SYMBOL_GPL(spi_add_device);
- /**
- * spi_new_device - instantiate one new SPI device
- * @ctlr: Controller to which device is connected
- * @chip: Describes the SPI device
- * Context: can sleep
- *
- * On typical mainboards, this is purely internal; and it's not needed
- * after board init creates the hard-wired devices. Some development
- * platforms may not be able to use spi_register_board_info though, and
- * this is exported so that for example a USB or parport based adapter
- * driver could add devices (which it would learn about out-of-band).
- *
- * Return: the new device, or NULL.
- */
- struct spi_device *spi_new_device(struct spi_controller *ctlr,
- struct spi_board_info *chip)
- {
- struct spi_device *proxy;
- int status;
- /* NOTE: caller did any chip->bus_num checks necessary.
- *
- * Also, unless we change the return value convention to use
- * error-or-pointer (not NULL-or-pointer), troubleshootability
- * suggests syslogged diagnostics are best here (ugh).
- */
- proxy = spi_alloc_device(ctlr);
- if (!proxy)
- return NULL;
- WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
- proxy->chip_select = chip->chip_select;
- proxy->max_speed_hz = chip->max_speed_hz;
- proxy->mode = chip->mode;
- proxy->irq = chip->irq;
- strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
- proxy->dev.platform_data = (void *) chip->platform_data;
- proxy->controller_data = chip->controller_data;
- proxy->controller_state = NULL;
- if (chip->properties) {
- status = device_add_properties(&proxy->dev, chip->properties);
- if (status) {
- dev_err(&ctlr->dev,
- "failed to add properties to '%s': %d\n",
- chip->modalias, status);
- goto err_dev_put;
- }
- }
- status = spi_add_device(proxy);
- if (status < 0)
- goto err_remove_props;
- return proxy;
- err_remove_props:
- if (chip->properties)
- device_remove_properties(&proxy->dev);
- err_dev_put:
- spi_dev_put(proxy);
- return NULL;
- }
- EXPORT_SYMBOL_GPL(spi_new_device);
- /**
- * spi_unregister_device - unregister a single SPI device
- * @spi: spi_device to unregister
- *
- * Start making the passed SPI device vanish. Normally this would be handled
- * by spi_unregister_controller().
- */
- void spi_unregister_device(struct spi_device *spi)
- {
- if (!spi)
- return;
- if (spi->dev.of_node) {
- of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
- of_node_put(spi->dev.of_node);
- }
- if (ACPI_COMPANION(&spi->dev))
- acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
- device_del(&spi->dev);
- spi_cleanup(spi);
- put_device(&spi->dev);
- }
- EXPORT_SYMBOL_GPL(spi_unregister_device);
- static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr,
- struct spi_board_info *bi)
- {
- struct spi_device *dev;
- if (ctlr->bus_num != bi->bus_num)
- return;
- dev = spi_new_device(ctlr, bi);
- if (!dev)
- dev_err(ctlr->dev.parent, "can't create new device for %s\n",
- bi->modalias);
- }
- /**
- * spi_register_board_info - register SPI devices for a given board
- * @info: array of chip descriptors
- * @n: how many descriptors are provided
- * Context: can sleep
- *
- * Board-specific early init code calls this (probably during arch_initcall)
- * with segments of the SPI device table. Any device nodes are created later,
- * after the relevant parent SPI controller (bus_num) is defined. We keep
- * this table of devices forever, so that reloading a controller driver will
- * not make Linux forget about these hard-wired devices.
- *
- * Other code can also call this, e.g. a particular add-on board might provide
- * SPI devices through its expansion connector, so code initializing that board
- * would naturally declare its SPI devices.
- *
- * The board info passed can safely be __initdata ... but be careful of
- * any embedded pointers (platform_data, etc), they're copied as-is.
- * Device properties are deep-copied though.
- *
- * Return: zero on success, else a negative error code.
- */
- int spi_register_board_info(struct spi_board_info const *info, unsigned n)
- {
- struct boardinfo *bi;
- int i;
- if (!n)
- return 0;
- bi = kcalloc(n, sizeof(*bi), GFP_KERNEL);
- if (!bi)
- return -ENOMEM;
- for (i = 0; i < n; i++, bi++, info++) {
- struct spi_controller *ctlr;
- memcpy(&bi->board_info, info, sizeof(*info));
- if (info->properties) {
- bi->board_info.properties =
- property_entries_dup(info->properties);
- if (IS_ERR(bi->board_info.properties))
- return PTR_ERR(bi->board_info.properties);
- }
- mutex_lock(&board_lock);
- list_add_tail(&bi->list, &board_list);
- list_for_each_entry(ctlr, &spi_controller_list, list)
- spi_match_controller_to_boardinfo(ctlr,
- &bi->board_info);
- mutex_unlock(&board_lock);
- }
- return 0;
- }
- /*-------------------------------------------------------------------------*/
- static void spi_set_cs(struct spi_device *spi, bool enable, bool force)
- {
- bool enable1 = enable;
- /*
- * Avoid calling into the driver (or doing delays) if the chip select
- * isn't actually changing from the last time this was called.
- */
- if (!force && (spi->controller->last_cs_enable == enable) &&
- (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH)))
- return;
- spi->controller->last_cs_enable = enable;
- spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
- if (!spi->controller->set_cs_timing) {
- if (enable1)
- spi_delay_exec(&spi->controller->cs_setup, NULL);
- else
- spi_delay_exec(&spi->controller->cs_hold, NULL);
- }
- if (spi->mode & SPI_CS_HIGH)
- enable = !enable;
- if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio)) {
- if (!(spi->mode & SPI_NO_CS)) {
- if (spi->cs_gpiod) {
- /*
- * Historically ACPI has no means of the GPIO polarity and
- * thus the SPISerialBus() resource defines it on the per-chip
- * basis. In order to avoid a chain of negations, the GPIO
- * polarity is considered being Active High. Even for the cases
- * when _DSD() is involved (in the updated versions of ACPI)
- * the GPIO CS polarity must be defined Active High to avoid
- * ambiguity. That's why we use enable, that takes SPI_CS_HIGH
- * into account.
- */
- if (has_acpi_companion(&spi->dev))
- gpiod_set_value_cansleep(spi->cs_gpiod, !enable);
- else
- /* Polarity handled by GPIO library */
- gpiod_set_value_cansleep(spi->cs_gpiod, enable1);
- } else {
- /*
- * invert the enable line, as active low is
- * default for SPI.
- */
- gpio_set_value_cansleep(spi->cs_gpio, !enable);
- }
- }
- /* Some SPI masters need both GPIO CS & slave_select */
- if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
- spi->controller->set_cs)
- spi->controller->set_cs(spi, !enable);
- } else if (spi->controller->set_cs) {
- spi->controller->set_cs(spi, !enable);
- }
- if (!spi->controller->set_cs_timing) {
- if (!enable1)
- spi_delay_exec(&spi->controller->cs_inactive, NULL);
- }
- }
- #ifdef CONFIG_HAS_DMA
- int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
- struct sg_table *sgt, void *buf, size_t len,
- enum dma_data_direction dir)
- {
- const bool vmalloced_buf = is_vmalloc_addr(buf);
- unsigned int max_seg_size = dma_get_max_seg_size(dev);
- #ifdef CONFIG_HIGHMEM
- const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
- (unsigned long)buf < (PKMAP_BASE +
- (LAST_PKMAP * PAGE_SIZE)));
- #else
- const bool kmap_buf = false;
- #endif
- int desc_len;
- int sgs;
- struct page *vm_page;
- struct scatterlist *sg;
- void *sg_buf;
- size_t min;
- int i, ret;
- if (vmalloced_buf || kmap_buf) {
- desc_len = min_t(unsigned long, max_seg_size, PAGE_SIZE);
- sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
- } else if (virt_addr_valid(buf)) {
- desc_len = min_t(size_t, max_seg_size, ctlr->max_dma_len);
- sgs = DIV_ROUND_UP(len, desc_len);
- } else {
- return -EINVAL;
- }
- ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
- if (ret != 0)
- return ret;
- sg = &sgt->sgl[0];
- for (i = 0; i < sgs; i++) {
- if (vmalloced_buf || kmap_buf) {
- /*
- * Next scatterlist entry size is the minimum between
- * the desc_len and the remaining buffer length that
- * fits in a page.
- */
- min = min_t(size_t, desc_len,
- min_t(size_t, len,
- PAGE_SIZE - offset_in_page(buf)));
- if (vmalloced_buf)
- vm_page = vmalloc_to_page(buf);
- else
- vm_page = kmap_to_page(buf);
- if (!vm_page) {
- sg_free_table(sgt);
- return -ENOMEM;
- }
- sg_set_page(sg, vm_page,
- min, offset_in_page(buf));
- } else {
- min = min_t(size_t, len, desc_len);
- sg_buf = buf;
- sg_set_buf(sg, sg_buf, min);
- }
- buf += min;
- len -= min;
- sg = sg_next(sg);
- }
- ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
- if (!ret)
- ret = -ENOMEM;
- if (ret < 0) {
- sg_free_table(sgt);
- return ret;
- }
- sgt->nents = ret;
- return 0;
- }
- void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev,
- struct sg_table *sgt, enum dma_data_direction dir)
- {
- if (sgt->orig_nents) {
- dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
- sg_free_table(sgt);
- }
- }
- static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
- {
- struct device *tx_dev, *rx_dev;
- struct spi_transfer *xfer;
- int ret;
- if (!ctlr->can_dma)
- return 0;
- if (ctlr->dma_tx)
- tx_dev = ctlr->dma_tx->device->dev;
- else
- tx_dev = ctlr->dev.parent;
- if (ctlr->dma_rx)
- rx_dev = ctlr->dma_rx->device->dev;
- else
- rx_dev = ctlr->dev.parent;
- list_for_each_entry(xfer, &msg->transfers, transfer_list) {
- if (!ctlr->can_dma(ctlr, msg->spi, xfer))
- continue;
- if (xfer->tx_buf != NULL) {
- ret = spi_map_buf(ctlr, tx_dev, &xfer->tx_sg,
- (void *)xfer->tx_buf, xfer->len,
- DMA_TO_DEVICE);
- if (ret != 0)
- return ret;
- }
- if (xfer->rx_buf != NULL) {
- ret = spi_map_buf(ctlr, rx_dev, &xfer->rx_sg,
- xfer->rx_buf, xfer->len,
- DMA_FROM_DEVICE);
- if (ret != 0) {
- spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg,
- DMA_TO_DEVICE);
- return ret;
- }
- }
- }
- ctlr->cur_msg_mapped = true;
- return 0;
- }
- static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg)
- {
- struct spi_transfer *xfer;
- struct device *tx_dev, *rx_dev;
- if (!ctlr->cur_msg_mapped || !ctlr->can_dma)
- return 0;
- if (ctlr->dma_tx)
- tx_dev = ctlr->dma_tx->device->dev;
- else
- tx_dev = ctlr->dev.parent;
- if (ctlr->dma_rx)
- rx_dev = ctlr->dma_rx->device->dev;
- else
- rx_dev = ctlr->dev.parent;
- list_for_each_entry(xfer, &msg->transfers, transfer_list) {
- if (!ctlr->can_dma(ctlr, msg->spi, xfer))
- continue;
- spi_unmap_buf(ctlr, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
- spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
- }
- ctlr->cur_msg_mapped = false;
- return 0;
- }
- #else /* !CONFIG_HAS_DMA */
- static inline int __spi_map_msg(struct spi_controller *ctlr,
- struct spi_message *msg)
- {
- return 0;
- }
- static inline int __spi_unmap_msg(struct spi_controller *ctlr,
- struct spi_message *msg)
- {
- return 0;
- }
- #endif /* !CONFIG_HAS_DMA */
- static inline int spi_unmap_msg(struct spi_controller *ctlr,
- struct spi_message *msg)
- {
- struct spi_transfer *xfer;
- list_for_each_entry(xfer, &msg->transfers, transfer_list) {
- /*
- * Restore the original value of tx_buf or rx_buf if they are
- * NULL.
- */
- if (xfer->tx_buf == ctlr->dummy_tx)
- xfer->tx_buf = NULL;
- if (xfer->rx_buf == ctlr->dummy_rx)
- xfer->rx_buf = NULL;
- }
- return __spi_unmap_msg(ctlr, msg);
- }
- static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
- {
- struct spi_transfer *xfer;
- void *tmp;
- unsigned int max_tx, max_rx;
- if ((ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX))
- && !(msg->spi->mode & SPI_3WIRE)) {
- max_tx = 0;
- max_rx = 0;
- list_for_each_entry(xfer, &msg->transfers, transfer_list) {
- if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) &&
- !xfer->tx_buf)
- max_tx = max(xfer->len, max_tx);
- if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) &&
- !xfer->rx_buf)
- max_rx = max(xfer->len, max_rx);
- }
- if (max_tx) {
- tmp = krealloc(ctlr->dummy_tx, max_tx,
- GFP_KERNEL | GFP_DMA);
- if (!tmp)
- return -ENOMEM;
- ctlr->dummy_tx = tmp;
- memset(tmp, 0, max_tx);
- }
- if (max_rx) {
- tmp = krealloc(ctlr->dummy_rx, max_rx,
- GFP_KERNEL | GFP_DMA);
- if (!tmp)
- return -ENOMEM;
- ctlr->dummy_rx = tmp;
- }
- if (max_tx || max_rx) {
- list_for_each_entry(xfer, &msg->transfers,
- transfer_list) {
- if (!xfer->len)
- continue;
- if (!xfer->tx_buf)
- xfer->tx_buf = ctlr->dummy_tx;
- if (!xfer->rx_buf)
- xfer->rx_buf = ctlr->dummy_rx;
- }
- }
- }
- return __spi_map_msg(ctlr, msg);
- }
- static int spi_transfer_wait(struct spi_controller *ctlr,
- struct spi_message *msg,
- struct spi_transfer *xfer)
- {
- struct spi_statistics *statm = &ctlr->statistics;
- struct spi_statistics *stats = &msg->spi->statistics;
- u32 speed_hz = xfer->speed_hz;
- unsigned long long ms;
- if (spi_controller_is_slave(ctlr)) {
- if (wait_for_completion_interruptible(&ctlr->xfer_completion)) {
- dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n");
- return -EINTR;
- }
- } else {
- if (!speed_hz)
- speed_hz = 100000;
- ms = 8LL * 1000LL * xfer->len;
- do_div(ms, speed_hz);
- ms += ms + 200; /* some tolerance */
- if (ms > UINT_MAX)
- ms = UINT_MAX;
- ms = wait_for_completion_timeout(&ctlr->xfer_completion,
- msecs_to_jiffies(ms));
- if (ms == 0) {
- SPI_STATISTICS_INCREMENT_FIELD(statm, timedout);
- SPI_STATISTICS_INCREMENT_FIELD(stats, timedout);
- dev_err(&msg->spi->dev,
- "SPI transfer timed out\n");
- return -ETIMEDOUT;
- }
- }
- return 0;
- }
- static void _spi_transfer_delay_ns(u32 ns)
- {
- if (!ns)
- return;
- if (ns <= 1000) {
- ndelay(ns);
- } else {
- u32 us = DIV_ROUND_UP(ns, 1000);
- if (us <= 10)
- udelay(us);
- else
- usleep_range(us, us + DIV_ROUND_UP(us, 10));
- }
- }
- int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer)
- {
- u32 delay = _delay->value;
- u32 unit = _delay->unit;
- u32 hz;
- if (!delay)
- return 0;
- switch (unit) {
- case SPI_DELAY_UNIT_USECS:
- delay *= 1000;
- break;
- case SPI_DELAY_UNIT_NSECS: /* nothing to do here */
- break;
- case SPI_DELAY_UNIT_SCK:
- /* clock cycles need to be obtained from spi_transfer */
- if (!xfer)
- return -EINVAL;
- /* if there is no effective speed know, then approximate
- * by underestimating with half the requested hz
- */
- hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2;
- if (!hz)
- return -EINVAL;
- delay *= DIV_ROUND_UP(1000000000, hz);
- break;
- default:
- return -EINVAL;
- }
- return delay;
- }
- EXPORT_SYMBOL_GPL(spi_delay_to_ns);
- int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer)
- {
- int delay;
- might_sleep();
- if (!_delay)
- return -EINVAL;
- delay = spi_delay_to_ns(_delay, xfer);
- if (delay < 0)
- return delay;
- _spi_transfer_delay_ns(delay);
- return 0;
- }
- EXPORT_SYMBOL_GPL(spi_delay_exec);
- static void _spi_transfer_cs_change_delay(struct spi_message *msg,
- struct spi_transfer *xfer)
- {
- u32 delay = xfer->cs_change_delay.value;
- u32 unit = xfer->cs_change_delay.unit;
- int ret;
- /* return early on "fast" mode - for everything but USECS */
- if (!delay) {
- if (unit == SPI_DELAY_UNIT_USECS)
- _spi_transfer_delay_ns(10000);
- return;
- }
- ret = spi_delay_exec(&xfer->cs_change_delay, xfer);
- if (ret) {
- dev_err_once(&msg->spi->dev,
- "Use of unsupported delay unit %i, using default of 10us\n",
- unit);
- _spi_transfer_delay_ns(10000);
- }
- }
- /*
- * spi_transfer_one_message - Default implementation of transfer_one_message()
- *
- * This is a standard implementation of transfer_one_message() for
- * drivers which implement a transfer_one() operation. It provides
- * standard handling of delays and chip select management.
- */
- static int spi_transfer_one_message(struct spi_controller *ctlr,
- struct spi_message *msg)
- {
- struct spi_transfer *xfer;
- bool keep_cs = false;
- int ret = 0;
- struct spi_statistics *statm = &ctlr->statistics;
- struct spi_statistics *stats = &msg->spi->statistics;
- spi_set_cs(msg->spi, true, false);
- SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
- SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
- list_for_each_entry(xfer, &msg->transfers, transfer_list) {
- trace_spi_transfer_start(msg, xfer);
- spi_statistics_add_transfer_stats(statm, xfer, ctlr);
- spi_statistics_add_transfer_stats(stats, xfer, ctlr);
- if (!ctlr->ptp_sts_supported) {
- xfer->ptp_sts_word_pre = 0;
- ptp_read_system_prets(xfer->ptp_sts);
- }
- if ((xfer->tx_buf || xfer->rx_buf) && xfer->len) {
- reinit_completion(&ctlr->xfer_completion);
- fallback_pio:
- ret = ctlr->transfer_one(ctlr, msg->spi, xfer);
- if (ret < 0) {
- if (ctlr->cur_msg_mapped &&
- (xfer->error & SPI_TRANS_FAIL_NO_START)) {
- __spi_unmap_msg(ctlr, msg);
- ctlr->fallback = true;
- xfer->error &= ~SPI_TRANS_FAIL_NO_START;
- goto fallback_pio;
- }
- SPI_STATISTICS_INCREMENT_FIELD(statm,
- errors);
- SPI_STATISTICS_INCREMENT_FIELD(stats,
- errors);
- dev_err(&msg->spi->dev,
- "SPI transfer failed: %d\n", ret);
- goto out;
- }
- if (ret > 0) {
- ret = spi_transfer_wait(ctlr, msg, xfer);
- if (ret < 0)
- msg->status = ret;
- }
- } else {
- if (xfer->len)
- dev_err(&msg->spi->dev,
- "Bufferless transfer has length %u\n",
- xfer->len);
- }
- if (!ctlr->ptp_sts_supported) {
- ptp_read_system_postts(xfer->ptp_sts);
- xfer->ptp_sts_word_post = xfer->len;
- }
- trace_spi_transfer_stop(msg, xfer);
- if (msg->status != -EINPROGRESS)
- goto out;
- spi_transfer_delay_exec(xfer);
- if (xfer->cs_change) {
- if (list_is_last(&xfer->transfer_list,
- &msg->transfers)) {
- keep_cs = true;
- } else {
- spi_set_cs(msg->spi, false, false);
- _spi_transfer_cs_change_delay(msg, xfer);
- spi_set_cs(msg->spi, true, false);
- }
- }
- msg->actual_length += xfer->len;
- }
- out:
- if (ret != 0 || !keep_cs)
- spi_set_cs(msg->spi, false, false);
- if (msg->status == -EINPROGRESS)
- msg->status = ret;
- if (msg->status && ctlr->handle_err)
- ctlr->handle_err(ctlr, msg);
- spi_finalize_current_message(ctlr);
- return ret;
- }
- /**
- * spi_finalize_current_transfer - report completion of a transfer
- * @ctlr: the controller reporting completion
- *
- * Called by SPI drivers using the core transfer_one_message()
- * implementation to notify it that the current interrupt driven
- * transfer has finished and the next one may be scheduled.
- */
- void spi_finalize_current_transfer(struct spi_controller *ctlr)
- {
- complete(&ctlr->xfer_completion);
- }
- EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
- static void spi_idle_runtime_pm(struct spi_controller *ctlr)
- {
- if (ctlr->auto_runtime_pm) {
- pm_runtime_mark_last_busy(ctlr->dev.parent);
- pm_runtime_put_autosuspend(ctlr->dev.parent);
- }
- }
- /**
- * __spi_pump_messages - function which processes spi message queue
- * @ctlr: controller to process queue for
- * @in_kthread: true if we are in the context of the message pump thread
- *
- * This function checks if there is any spi message in the queue that
- * needs processing and if so call out to the driver to initialize hardware
- * and transfer each message.
- *
- * Note that it is called both from the kthread itself and also from
- * inside spi_sync(); the queue extraction handling at the top of the
- * function should deal with this safely.
- */
- static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
- {
- struct spi_transfer *xfer;
- struct spi_message *msg;
- bool was_busy = false;
- unsigned long flags;
- int ret;
- /* Lock queue */
- spin_lock_irqsave(&ctlr->queue_lock, flags);
- /* Make sure we are not already running a message */
- if (ctlr->cur_msg) {
- spin_unlock_irqrestore(&ctlr->queue_lock, flags);
- return;
- }
- /* If another context is idling the device then defer */
- if (ctlr->idling) {
- kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
- spin_unlock_irqrestore(&ctlr->queue_lock, flags);
- return;
- }
- /* Check if the queue is idle */
- if (list_empty(&ctlr->queue) || !ctlr->running) {
- if (!ctlr->busy) {
- spin_unlock_irqrestore(&ctlr->queue_lock, flags);
- return;
- }
- /* Defer any non-atomic teardown to the thread */
- if (!in_kthread) {
- if (!ctlr->dummy_rx && !ctlr->dummy_tx &&
- !ctlr->unprepare_transfer_hardware) {
- spi_idle_runtime_pm(ctlr);
- ctlr->busy = false;
- trace_spi_controller_idle(ctlr);
- } else {
- kthread_queue_work(ctlr->kworker,
- &ctlr->pump_messages);
- }
- spin_unlock_irqrestore(&ctlr->queue_lock, flags);
- return;
- }
- ctlr->busy = false;
- ctlr->idling = true;
- spin_unlock_irqrestore(&ctlr->queue_lock, flags);
- kfree(ctlr->dummy_rx);
- ctlr->dummy_rx = NULL;
- kfree(ctlr->dummy_tx);
- ctlr->dummy_tx = NULL;
- if (ctlr->unprepare_transfer_hardware &&
- ctlr->unprepare_transfer_hardware(ctlr))
- dev_err(&ctlr->dev,
- "failed to unprepare transfer hardware\n");
- spi_idle_runtime_pm(ctlr);
- trace_spi_controller_idle(ctlr);
- spin_lock_irqsave(&ctlr->queue_lock, flags);
- ctlr->idling = false;
- spin_unlock_irqrestore(&ctlr->queue_lock, flags);
- return;
- }
- /* Extract head of queue */
- msg = list_first_entry(&ctlr->queue, struct spi_message, queue);
- ctlr->cur_msg = msg;
- list_del_init(&msg->queue);
- if (ctlr->busy)
- was_busy = true;
- else
- ctlr->busy = true;
- spin_unlock_irqrestore(&ctlr->queue_lock, flags);
- mutex_lock(&ctlr->io_mutex);
- if (!was_busy && ctlr->auto_runtime_pm) {
- ret = pm_runtime_get_sync(ctlr->dev.parent);
- if (ret < 0) {
- pm_runtime_put_noidle(ctlr->dev.parent);
- dev_err(&ctlr->dev, "Failed to power device: %d\n",
- ret);
- mutex_unlock(&ctlr->io_mutex);
- return;
- }
- }
- if (!was_busy)
- trace_spi_controller_busy(ctlr);
- if (!was_busy && ctlr->prepare_transfer_hardware) {
- ret = ctlr->prepare_transfer_hardware(ctlr);
- if (ret) {
- dev_err(&ctlr->dev,
- "failed to prepare transfer hardware: %d\n",
- ret);
- if (ctlr->auto_runtime_pm)
- pm_runtime_put(ctlr->dev.parent);
- msg->status = ret;
- spi_finalize_current_message(ctlr);
- mutex_unlock(&ctlr->io_mutex);
- return;
- }
- }
- trace_spi_message_start(msg);
- if (ctlr->prepare_message) {
- ret = ctlr->prepare_message(ctlr, msg);
- if (ret) {
- dev_err(&ctlr->dev, "failed to prepare message: %d\n",
- ret);
- msg->status = ret;
- spi_finalize_current_message(ctlr);
- goto out;
- }
- ctlr->cur_msg_prepared = true;
- }
- ret = spi_map_msg(ctlr, msg);
- if (ret) {
- msg->status = ret;
- spi_finalize_current_message(ctlr);
- goto out;
- }
- if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
- list_for_each_entry(xfer, &msg->transfers, transfer_list) {
- xfer->ptp_sts_word_pre = 0;
- ptp_read_system_prets(xfer->ptp_sts);
- }
- }
- ret = ctlr->transfer_one_message(ctlr, msg);
- if (ret) {
- dev_err(&ctlr->dev,
- "failed to transfer one message from queue\n");
- goto out;
- }
- out:
- mutex_unlock(&ctlr->io_mutex);
- /* Prod the scheduler in case transfer_one() was busy waiting */
- if (!ret)
- cond_resched();
- }
- /**
- * spi_pump_messages - kthread work function which processes spi message queue
- * @work: pointer to kthread work struct contained in the controller struct
- */
- static void spi_pump_messages(struct kthread_work *work)
- {
- struct spi_controller *ctlr =
- container_of(work, struct spi_controller, pump_messages);
- __spi_pump_messages(ctlr, true);
- }
- /**
- * spi_take_timestamp_pre - helper for drivers to collect the beginning of the
- * TX timestamp for the requested byte from the SPI
- * transfer. The frequency with which this function
- * must be called (once per word, once for the whole
- * transfer, once per batch of words etc) is arbitrary
- * as long as the @tx buffer offset is greater than or
- * equal to the requested byte at the time of the
- * call. The timestamp is only taken once, at the
- * first such call. It is assumed that the driver
- * advances its @tx buffer pointer monotonically.
- * @ctlr: Pointer to the spi_controller structure of the driver
- * @xfer: Pointer to the transfer being timestamped
- * @progress: How many words (not bytes) have been transferred so far
- * @irqs_off: If true, will disable IRQs and preemption for the duration of the
- * transfer, for less jitter in time measurement. Only compatible
- * with PIO drivers. If true, must follow up with
- * spi_take_timestamp_post or otherwise system will crash.
- * WARNING: for fully predictable results, the CPU frequency must
- * also be under control (governor).
- */
- void spi_take_timestamp_pre(struct spi_controller *ctlr,
- struct spi_transfer *xfer,
- size_t progress, bool irqs_off)
- {
- if (!xfer->ptp_sts)
- return;
- if (xfer->timestamped)
- return;
- if (progress > xfer->ptp_sts_word_pre)
- return;
- /* Capture the resolution of the timestamp */
- xfer->ptp_sts_word_pre = progress;
- if (irqs_off) {
- local_irq_save(ctlr->irq_flags);
- preempt_disable();
- }
- ptp_read_system_prets(xfer->ptp_sts);
- }
- EXPORT_SYMBOL_GPL(spi_take_timestamp_pre);
- /**
- * spi_take_timestamp_post - helper for drivers to collect the end of the
- * TX timestamp for the requested byte from the SPI
- * transfer. Can be called with an arbitrary
- * frequency: only the first call where @tx exceeds
- * or is equal to the requested word will be
- * timestamped.
- * @ctlr: Pointer to the spi_controller structure of the driver
- * @xfer: Pointer to the transfer being timestamped
- * @progress: How many words (not bytes) have been transferred so far
- * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU.
- */
- void spi_take_timestamp_post(struct spi_controller *ctlr,
- struct spi_transfer *xfer,
- size_t progress, bool irqs_off)
- {
- if (!xfer->ptp_sts)
- return;
- if (xfer->timestamped)
- return;
- if (progress < xfer->ptp_sts_word_post)
- return;
- ptp_read_system_postts(xfer->ptp_sts);
- if (irqs_off) {
- local_irq_restore(ctlr->irq_flags);
- preempt_enable();
- }
- /* Capture the resolution of the timestamp */
- xfer->ptp_sts_word_post = progress;
- xfer->timestamped = true;
- }
- EXPORT_SYMBOL_GPL(spi_take_timestamp_post);
- /**
- * spi_set_thread_rt - set the controller to pump at realtime priority
- * @ctlr: controller to boost priority of
- *
- * This can be called because the controller requested realtime priority
- * (by setting the ->rt value before calling spi_register_controller()) or
- * because a device on the bus said that its transfers needed realtime
- * priority.
- *
- * NOTE: at the moment if any device on a bus says it needs realtime then
- * the thread will be at realtime priority for all transfers on that
- * controller. If this eventually becomes a problem we may see if we can
- * find a way to boost the priority only temporarily during relevant
- * transfers.
- */
- static void spi_set_thread_rt(struct spi_controller *ctlr)
- {
- dev_info(&ctlr->dev,
- "will run message pump with realtime priority\n");
- sched_set_fifo(ctlr->kworker->task);
- }
- static int spi_init_queue(struct spi_controller *ctlr)
- {
- ctlr->running = false;
- ctlr->busy = false;
- ctlr->kworker = kthread_create_worker(0, dev_name(&ctlr->dev));
- if (IS_ERR(ctlr->kworker)) {
- dev_err(&ctlr->dev, "failed to create message pump kworker\n");
- return PTR_ERR(ctlr->kworker);
- }
- kthread_init_work(&ctlr->pump_messages, spi_pump_messages);
- /*
- * Controller config will indicate if this controller should run the
- * message pump with high (realtime) priority to reduce the transfer
- * latency on the bus by minimising the delay between a transfer
- * request and the scheduling of the message pump thread. Without this
- * setting the message pump thread will remain at default priority.
- */
- if (ctlr->rt)
- spi_set_thread_rt(ctlr);
- return 0;
- }
- /**
- * spi_get_next_queued_message() - called by driver to check for queued
- * messages
- * @ctlr: the controller to check for queued messages
- *
- * If there are more messages in the queue, the next message is returned from
- * this call.
- *
- * Return: the next message in the queue, else NULL if the queue is empty.
- */
- struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr)
- {
- struct spi_message *next;
- unsigned long flags;
- /* get a pointer to the next message, if any */
- spin_lock_irqsave(&ctlr->queue_lock, flags);
- next = list_first_entry_or_null(&ctlr->queue, struct spi_message,
- queue);
- spin_unlock_irqrestore(&ctlr->queue_lock, flags);
- return next;
- }
- EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
- /**
- * spi_finalize_current_message() - the current message is complete
- * @ctlr: the controller to return the message to
- *
- * Called by the driver to notify the core that the message in the front of the
- * queue is complete and can be removed from the queue.
- */
- void spi_finalize_current_message(struct spi_controller *ctlr)
- {
- struct spi_transfer *xfer;
- struct spi_message *mesg;
- unsigned long flags;
- int ret;
- spin_lock_irqsave(&ctlr->queue_lock, flags);
- mesg = ctlr->cur_msg;
- spin_unlock_irqrestore(&ctlr->queue_lock, flags);
- if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
- list_for_each_entry(xfer, &mesg->transfers, transfer_list) {
- ptp_read_system_postts(xfer->ptp_sts);
- xfer->ptp_sts_word_post = xfer->len;
- }
- }
- if (unlikely(ctlr->ptp_sts_supported))
- list_for_each_entry(xfer, &mesg->transfers, transfer_list)
- WARN_ON_ONCE(xfer->ptp_sts && !xfer->timestamped);
- spi_unmap_msg(ctlr, mesg);
- /* In the prepare_messages callback the spi bus has the opportunity to
- * split a transfer to smaller chunks.
- * Release splited transfers here since spi_map_msg is done on the
- * splited transfers.
- */
- spi_res_release(ctlr, mesg);
- if (ctlr->cur_msg_prepared && ctlr->unprepare_message) {
- ret = ctlr->unprepare_message(ctlr, mesg);
- if (ret) {
- dev_err(&ctlr->dev, "failed to unprepare message: %d\n",
- ret);
- }
- }
- spin_lock_irqsave(&ctlr->queue_lock, flags);
- ctlr->cur_msg = NULL;
- ctlr->cur_msg_prepared = false;
- ctlr->fallback = false;
- kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
- spin_unlock_irqrestore(&ctlr->queue_lock, flags);
- trace_spi_message_done(mesg);
- mesg->state = NULL;
- if (mesg->complete)
- mesg->complete(mesg->context);
- }
- EXPORT_SYMBOL_GPL(spi_finalize_current_message);
- static int spi_start_queue(struct spi_controller *ctlr)
- {
- unsigned long flags;
- spin_lock_irqsave(&ctlr->queue_lock, flags);
- if (ctlr->running || ctlr->busy) {
- spin_unlock_irqrestore(&ctlr->queue_lock, flags);
- return -EBUSY;
- }
- ctlr->running = true;
- ctlr->cur_msg = NULL;
- spin_unlock_irqrestore(&ctlr->queue_lock, flags);
- kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
- return 0;
- }
- static int spi_stop_queue(struct spi_controller *ctlr)
- {
- unsigned long flags;
- unsigned limit = 500;
- int ret = 0;
- spin_lock_irqsave(&ctlr->queue_lock, flags);
- /*
- * This is a bit lame, but is optimized for the common execution path.
- * A wait_queue on the ctlr->busy could be used, but then the common
- * execution path (pump_messages) would be required to call wake_up or
- * friends on every SPI message. Do this instead.
- */
- while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) {
- spin_unlock_irqrestore(&ctlr->queue_lock, flags);
- usleep_range(10000, 11000);
- spin_lock_irqsave(&ctlr->queue_lock, flags);
- }
- if (!list_empty(&ctlr->queue) || ctlr->busy)
- ret = -EBUSY;
- else
- ctlr->running = false;
- spin_unlock_irqrestore(&ctlr->queue_lock, flags);
- if (ret) {
- dev_warn(&ctlr->dev, "could not stop message queue\n");
- return ret;
- }
- return ret;
- }
- static int spi_destroy_queue(struct spi_controller *ctlr)
- {
- int ret;
- ret = spi_stop_queue(ctlr);
- /*
- * kthread_flush_worker will block until all work is done.
- * If the reason that stop_queue timed out is that the work will never
- * finish, then it does no good to call flush/stop thread, so
- * return anyway.
- */
- if (ret) {
- dev_err(&ctlr->dev, "problem destroying queue\n");
- return ret;
- }
- kthread_destroy_worker(ctlr->kworker);
- return 0;
- }
- static int __spi_queued_transfer(struct spi_device *spi,
- struct spi_message *msg,
- bool need_pump)
- {
- struct spi_controller *ctlr = spi->controller;
- unsigned long flags;
- spin_lock_irqsave(&ctlr->queue_lock, flags);
- if (!ctlr->running) {
- spin_unlock_irqrestore(&ctlr->queue_lock, flags);
- return -ESHUTDOWN;
- }
- msg->actual_length = 0;
- msg->status = -EINPROGRESS;
- list_add_tail(&msg->queue, &ctlr->queue);
- if (!ctlr->busy && need_pump)
- kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
- spin_unlock_irqrestore(&ctlr->queue_lock, flags);
- return 0;
- }
- /**
- * spi_queued_transfer - transfer function for queued transfers
- * @spi: spi device which is requesting transfer
- * @msg: spi message which is to handled is queued to driver queue
- *
- * Return: zero on success, else a negative error code.
- */
- static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
- {
- return __spi_queued_transfer(spi, msg, true);
- }
- static int spi_controller_initialize_queue(struct spi_controller *ctlr)
- {
- int ret;
- ctlr->transfer = spi_queued_transfer;
- if (!ctlr->transfer_one_message)
- ctlr->transfer_one_message = spi_transfer_one_message;
- /* Initialize and start queue */
- ret = spi_init_queue(ctlr);
- if (ret) {
- dev_err(&ctlr->dev, "problem initializing queue\n");
- goto err_init_queue;
- }
- ctlr->queued = true;
- ret = spi_start_queue(ctlr);
- if (ret) {
- dev_err(&ctlr->dev, "problem starting queue\n");
- goto err_start_queue;
- }
- return 0;
- err_start_queue:
- spi_destroy_queue(ctlr);
- err_init_queue:
- return ret;
- }
- /**
- * spi_flush_queue - Send all pending messages in the queue from the callers'
- * context
- * @ctlr: controller to process queue for
- *
- * This should be used when one wants to ensure all pending messages have been
- * sent before doing something. Is used by the spi-mem code to make sure SPI
- * memory operations do not preempt regular SPI transfers that have been queued
- * before the spi-mem operation.
- */
- void spi_flush_queue(struct spi_controller *ctlr)
- {
- if (ctlr->transfer == spi_queued_transfer)
- __spi_pump_messages(ctlr, false);
- }
- /*-------------------------------------------------------------------------*/
- #if defined(CONFIG_OF)
- static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
- struct device_node *nc)
- {
- u32 value;
- int rc;
- /* Mode (clock phase/polarity/etc.) */
- if (of_property_read_bool(nc, "spi-cpha"))
- spi->mode |= SPI_CPHA;
- if (of_property_read_bool(nc, "spi-cpol"))
- spi->mode |= SPI_CPOL;
- if (of_property_read_bool(nc, "spi-3wire"))
- spi->mode |= SPI_3WIRE;
- if (of_property_read_bool(nc, "spi-lsb-first"))
- spi->mode |= SPI_LSB_FIRST;
- if (of_property_read_bool(nc, "spi-cs-high"))
- spi->mode |= SPI_CS_HIGH;
- /* Device DUAL/QUAD mode */
- if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
- switch (value) {
- case 1:
- break;
- case 2:
- spi->mode |= SPI_TX_DUAL;
- break;
- case 4:
- spi->mode |= SPI_TX_QUAD;
- break;
- case 8:
- spi->mode |= SPI_TX_OCTAL;
- break;
- default:
- dev_warn(&ctlr->dev,
- "spi-tx-bus-width %d not supported\n",
- value);
- break;
- }
- }
- if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
- switch (value) {
- case 1:
- break;
- case 2:
- spi->mode |= SPI_RX_DUAL;
- break;
- case 4:
- spi->mode |= SPI_RX_QUAD;
- break;
- case 8:
- spi->mode |= SPI_RX_OCTAL;
- break;
- default:
- dev_warn(&ctlr->dev,
- "spi-rx-bus-width %d not supported\n",
- value);
- break;
- }
- }
- if (spi_controller_is_slave(ctlr)) {
- if (!of_node_name_eq(nc, "slave")) {
- dev_err(&ctlr->dev, "%pOF is not called 'slave'\n",
- nc);
- return -EINVAL;
- }
- return 0;
- }
- /* Device address */
- rc = of_property_read_u32(nc, "reg", &value);
- if (rc) {
- dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",
- nc, rc);
- return rc;
- }
- spi->chip_select = value;
- /* Device speed */
- if (!of_property_read_u32(nc, "spi-max-frequency", &value))
- spi->max_speed_hz = value;
- return 0;
- }
- static struct spi_device *
- of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)
- {
- struct spi_device *spi;
- int rc;
- /* Alloc an spi_device */
- spi = spi_alloc_device(ctlr);
- if (!spi) {
- dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc);
- rc = -ENOMEM;
- goto err_out;
- }
- /* Select device driver */
- rc = of_modalias_node(nc, spi->modalias,
- sizeof(spi->modalias));
- if (rc < 0) {
- dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc);
- goto err_out;
- }
- rc = of_spi_parse_dt(ctlr, spi, nc);
- if (rc)
- goto err_out;
- /* Store a pointer to the node in the device structure */
- of_node_get(nc);
- spi->dev.of_node = nc;
- spi->dev.fwnode = of_fwnode_handle(nc);
- /* Register the new device */
- rc = spi_add_device(spi);
- if (rc) {
- dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc);
- goto err_of_node_put;
- }
- return spi;
- err_of_node_put:
- of_node_put(nc);
- err_out:
- spi_dev_put(spi);
- return ERR_PTR(rc);
- }
- /**
- * of_register_spi_devices() - Register child devices onto the SPI bus
- * @ctlr: Pointer to spi_controller device
- *
- * Registers an spi_device for each child node of controller node which
- * represents a valid SPI slave.
- */
- static void of_register_spi_devices(struct spi_controller *ctlr)
- {
- struct spi_device *spi;
- struct device_node *nc;
- if (!ctlr->dev.of_node)
- return;
- for_each_available_child_of_node(ctlr->dev.of_node, nc) {
- if (of_node_test_and_set_flag(nc, OF_POPULATED))
- continue;
- spi = of_register_spi_device(ctlr, nc);
- if (IS_ERR(spi)) {
- dev_warn(&ctlr->dev,
- "Failed to create SPI device for %pOF\n", nc);
- of_node_clear_flag(nc, OF_POPULATED);
- }
- }
- }
- #else
- static void of_register_spi_devices(struct spi_controller *ctlr) { }
- #endif
- #ifdef CONFIG_ACPI
- struct acpi_spi_lookup {
- struct spi_controller *ctlr;
- u32 max_speed_hz;
- u32 mode;
- int irq;
- u8 bits_per_word;
- u8 chip_select;
- };
- static void acpi_spi_parse_apple_properties(struct acpi_device *dev,
- struct acpi_spi_lookup *lookup)
- {
- const union acpi_object *obj;
- if (!x86_apple_machine)
- return;
- if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj)
- && obj->buffer.length >= 4)
- lookup->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer;
- if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj)
- && obj->buffer.length == 8)
- lookup->bits_per_word = *(u64 *)obj->buffer.pointer;
- if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj)
- && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer)
- lookup->mode |= SPI_LSB_FIRST;
- if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj)
- && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
- lookup->mode |= SPI_CPOL;
- if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj)
- && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
- lookup->mode |= SPI_CPHA;
- }
- static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
- {
- struct acpi_spi_lookup *lookup = data;
- struct spi_controller *ctlr = lookup->ctlr;
- if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
- struct acpi_resource_spi_serialbus *sb;
- acpi_handle parent_handle;
- acpi_status status;
- sb = &ares->data.spi_serial_bus;
- if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
- status = acpi_get_handle(NULL,
- sb->resource_source.string_ptr,
- &parent_handle);
- if (ACPI_FAILURE(status) ||
- ACPI_HANDLE(ctlr->dev.parent) != parent_handle)
- return -ENODEV;
- /*
- * ACPI DeviceSelection numbering is handled by the
- * host controller driver in Windows and can vary
- * from driver to driver. In Linux we always expect
- * 0 .. max - 1 so we need to ask the driver to
- * translate between the two schemes.
- */
- if (ctlr->fw_translate_cs) {
- int cs = ctlr->fw_translate_cs(ctlr,
- sb->device_selection);
- if (cs < 0)
- return cs;
- lookup->chip_select = cs;
- } else {
- lookup->chip_select = sb->device_selection;
- }
- lookup->max_speed_hz = sb->connection_speed;
- lookup->bits_per_word = sb->data_bit_length;
- if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
- lookup->mode |= SPI_CPHA;
- if (sb->clock_polarity == ACPI_SPI_START_HIGH)
- lookup->mode |= SPI_CPOL;
- if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
- lookup->mode |= SPI_CS_HIGH;
- }
- } else if (lookup->irq < 0) {
- struct resource r;
- if (acpi_dev_resource_interrupt(ares, 0, &r))
- lookup->irq = r.start;
- }
- /* Always tell the ACPI core to skip this resource */
- return 1;
- }
- static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,
- struct acpi_device *adev)
- {
- acpi_handle parent_handle = NULL;
- struct list_head resource_list;
- struct acpi_spi_lookup lookup = {};
- struct spi_device *spi;
- int ret;
- if (acpi_bus_get_status(adev) || !adev->status.present ||
- acpi_device_enumerated(adev))
- return AE_OK;
- lookup.ctlr = ctlr;
- lookup.irq = -1;
- INIT_LIST_HEAD(&resource_list);
- ret = acpi_dev_get_resources(adev, &resource_list,
- acpi_spi_add_resource, &lookup);
- acpi_dev_free_resource_list(&resource_list);
- if (ret < 0)
- /* found SPI in _CRS but it points to another controller */
- return AE_OK;
- if (!lookup.max_speed_hz &&
- !ACPI_FAILURE(acpi_get_parent(adev->handle, &parent_handle)) &&
- ACPI_HANDLE(ctlr->dev.parent) == parent_handle) {
- /* Apple does not use _CRS but nested devices for SPI slaves */
- acpi_spi_parse_apple_properties(adev, &lookup);
- }
- if (!lookup.max_speed_hz)
- return AE_OK;
- spi = spi_alloc_device(ctlr);
- if (!spi) {
- dev_err(&ctlr->dev, "failed to allocate SPI device for %s\n",
- dev_name(&adev->dev));
- return AE_NO_MEMORY;
- }
- ACPI_COMPANION_SET(&spi->dev, adev);
- spi->max_speed_hz = lookup.max_speed_hz;
- spi->mode |= lookup.mode;
- spi->irq = lookup.irq;
- spi->bits_per_word = lookup.bits_per_word;
- spi->chip_select = lookup.chip_select;
- acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,
- sizeof(spi->modalias));
- if (spi->irq < 0)
- spi->irq = acpi_dev_gpio_irq_get(adev, 0);
- acpi_device_set_enumerated(adev);
- adev->power.flags.ignore_parent = true;
- if (spi_add_device(spi)) {
- adev->power.flags.ignore_parent = false;
- dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n",
- dev_name(&adev->dev));
- spi_dev_put(spi);
- }
- return AE_OK;
- }
- static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
- void *data, void **return_value)
- {
- struct spi_controller *ctlr = data;
- struct acpi_device *adev;
- if (acpi_bus_get_device(handle, &adev))
- return AE_OK;
- return acpi_register_spi_device(ctlr, adev);
- }
- #define SPI_ACPI_ENUMERATE_MAX_DEPTH 32
- static void acpi_register_spi_devices(struct spi_controller *ctlr)
- {
- acpi_status status;
- acpi_handle handle;
- handle = ACPI_HANDLE(ctlr->dev.parent);
- if (!handle)
- return;
- status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
- SPI_ACPI_ENUMERATE_MAX_DEPTH,
- acpi_spi_add_device, NULL, ctlr, NULL);
- if (ACPI_FAILURE(status))
- dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n");
- }
- #else
- static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {}
- #endif /* CONFIG_ACPI */
- static void spi_controller_release(struct device *dev)
- {
- struct spi_controller *ctlr;
- ctlr = container_of(dev, struct spi_controller, dev);
- kfree(ctlr);
- }
- static struct class spi_master_class = {
- .name = "spi_master",
- .owner = THIS_MODULE,
- .dev_release = spi_controller_release,
- .dev_groups = spi_master_groups,
- };
- #ifdef CONFIG_SPI_SLAVE
- /**
- * spi_slave_abort - abort the ongoing transfer request on an SPI slave
- * controller
- * @spi: device used for the current transfer
- */
- int spi_slave_abort(struct spi_device *spi)
- {
- struct spi_controller *ctlr = spi->controller;
- if (spi_controller_is_slave(ctlr) && ctlr->slave_abort)
- return ctlr->slave_abort(ctlr);
- return -ENOTSUPP;
- }
- EXPORT_SYMBOL_GPL(spi_slave_abort);
- static int match_true(struct device *dev, void *data)
- {
- return 1;
- }
- static ssize_t slave_show(struct device *dev, struct device_attribute *attr,
- char *buf)
- {
- struct spi_controller *ctlr = container_of(dev, struct spi_controller,
- dev);
- struct device *child;
- child = device_find_child(&ctlr->dev, NULL, match_true);
- return sprintf(buf, "%s\n",
- child ? to_spi_device(child)->modalias : NULL);
- }
- static ssize_t slave_store(struct device *dev, struct device_attribute *attr,
- const char *buf, size_t count)
- {
- struct spi_controller *ctlr = container_of(dev, struct spi_controller,
- dev);
- struct spi_device *spi;
- struct device *child;
- char name[32];
- int rc;
- rc = sscanf(buf, "%31s", name);
- if (rc != 1 || !name[0])
- return -EINVAL;
- child = device_find_child(&ctlr->dev, NULL, match_true);
- if (child) {
- /* Remove registered slave */
- device_unregister(child);
- put_device(child);
- }
- if (strcmp(name, "(null)")) {
- /* Register new slave */
- spi = spi_alloc_device(ctlr);
- if (!spi)
- return -ENOMEM;
- strlcpy(spi->modalias, name, sizeof(spi->modalias));
- rc = spi_add_device(spi);
- if (rc) {
- spi_dev_put(spi);
- return rc;
- }
- }
- return count;
- }
- static DEVICE_ATTR_RW(slave);
- static struct attribute *spi_slave_attrs[] = {
- &dev_attr_slave.attr,
- NULL,
- };
- static const struct attribute_group spi_slave_group = {
- .attrs = spi_slave_attrs,
- };
- static const struct attribute_group *spi_slave_groups[] = {
- &spi_controller_statistics_group,
- &spi_slave_group,
- NULL,
- };
- static struct class spi_slave_class = {
- .name = "spi_slave",
- .owner = THIS_MODULE,
- .dev_release = spi_controller_release,
- .dev_groups = spi_slave_groups,
- };
- #else
- extern struct class spi_slave_class; /* dummy */
- #endif
- /**
- * __spi_alloc_controller - allocate an SPI master or slave controller
- * @dev: the controller, possibly using the platform_bus
- * @size: how much zeroed driver-private data to allocate; the pointer to this
- * memory is in the driver_data field of the returned device, accessible
- * with spi_controller_get_devdata(); the memory is cacheline aligned;
- * drivers granting DMA access to portions of their private data need to
- * round up @size using ALIGN(size, dma_get_cache_alignment()).
- * @slave: flag indicating whether to allocate an SPI master (false) or SPI
- * slave (true) controller
- * Context: can sleep
- *
- * This call is used only by SPI controller drivers, which are the
- * only ones directly touching chip registers. It's how they allocate
- * an spi_controller structure, prior to calling spi_register_controller().
- *
- * This must be called from context that can sleep.
- *
- * The caller is responsible for assigning the bus number and initializing the
- * controller's methods before calling spi_register_controller(); and (after
- * errors adding the device) calling spi_controller_put() to prevent a memory
- * leak.
- *
- * Return: the SPI controller structure on success, else NULL.
- */
- struct spi_controller *__spi_alloc_controller(struct device *dev,
- unsigned int size, bool slave)
- {
- struct spi_controller *ctlr;
- size_t ctlr_size = ALIGN(sizeof(*ctlr), dma_get_cache_alignment());
- if (!dev)
- return NULL;
- ctlr = kzalloc(size + ctlr_size, GFP_KERNEL);
- if (!ctlr)
- return NULL;
- device_initialize(&ctlr->dev);
- ctlr->bus_num = -1;
- ctlr->num_chipselect = 1;
- ctlr->slave = slave;
- if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)
- ctlr->dev.class = &spi_slave_class;
- else
- ctlr->dev.class = &spi_master_class;
- ctlr->dev.parent = dev;
- pm_suspend_ignore_children(&ctlr->dev, true);
- spi_controller_set_devdata(ctlr, (void *)ctlr + ctlr_size);
- return ctlr;
- }
- EXPORT_SYMBOL_GPL(__spi_alloc_controller);
- static void devm_spi_release_controller(struct device *dev, void *ctlr)
- {
- spi_controller_put(*(struct spi_controller **)ctlr);
- }
- /**
- * __devm_spi_alloc_controller - resource-managed __spi_alloc_controller()
- * @dev: physical device of SPI controller
- * @size: how much zeroed driver-private data to allocate
- * @slave: whether to allocate an SPI master (false) or SPI slave (true)
- * Context: can sleep
- *
- * Allocate an SPI controller and automatically release a reference on it
- * when @dev is unbound from its driver. Drivers are thus relieved from
- * having to call spi_controller_put().
- *
- * The arguments to this function are identical to __spi_alloc_controller().
- *
- * Return: the SPI controller structure on success, else NULL.
- */
- struct spi_controller *__devm_spi_alloc_controller(struct device *dev,
- unsigned int size,
- bool slave)
- {
- struct spi_controller **ptr, *ctlr;
- ptr = devres_alloc(devm_spi_release_controller, sizeof(*ptr),
- GFP_KERNEL);
- if (!ptr)
- return NULL;
- ctlr = __spi_alloc_controller(dev, size, slave);
- if (ctlr) {
- *ptr = ctlr;
- devres_add(dev, ptr);
- } else {
- devres_free(ptr);
- }
- return ctlr;
- }
- EXPORT_SYMBOL_GPL(__devm_spi_alloc_controller);
- #ifdef CONFIG_OF
- static int of_spi_get_gpio_numbers(struct spi_controller *ctlr)
- {
- int nb, i, *cs;
- struct device_node *np = ctlr->dev.of_node;
- if (!np)
- return 0;
- nb = of_gpio_named_count(np, "cs-gpios");
- ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
- /* Return error only for an incorrectly formed cs-gpios property */
- if (nb == 0 || nb == -ENOENT)
- return 0;
- else if (nb < 0)
- return nb;
- cs = devm_kcalloc(&ctlr->dev, ctlr->num_chipselect, sizeof(int),
- GFP_KERNEL);
- ctlr->cs_gpios = cs;
- if (!ctlr->cs_gpios)
- return -ENOMEM;
- for (i = 0; i < ctlr->num_chipselect; i++)
- cs[i] = -ENOENT;
- for (i = 0; i < nb; i++)
- cs[i] = of_get_named_gpio(np, "cs-gpios", i);
- return 0;
- }
- #else
- static int of_spi_get_gpio_numbers(struct spi_controller *ctlr)
- {
- return 0;
- }
- #endif
- /**
- * spi_get_gpio_descs() - grab chip select GPIOs for the master
- * @ctlr: The SPI master to grab GPIO descriptors for
- */
- static int spi_get_gpio_descs(struct spi_controller *ctlr)
- {
- int nb, i;
- struct gpio_desc **cs;
- struct device *dev = &ctlr->dev;
- unsigned long native_cs_mask = 0;
- unsigned int num_cs_gpios = 0;
- nb = gpiod_count(dev, "cs");
- ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
- /* No GPIOs at all is fine, else return the error */
- if (nb == 0 || nb == -ENOENT)
- return 0;
- else if (nb < 0)
- return nb;
- cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs),
- GFP_KERNEL);
- if (!cs)
- return -ENOMEM;
- ctlr->cs_gpiods = cs;
- for (i = 0; i < nb; i++) {
- /*
- * Most chipselects are active low, the inverted
- * semantics are handled by special quirks in gpiolib,
- * so initializing them GPIOD_OUT_LOW here means
- * "unasserted", in most cases this will drive the physical
- * line high.
- */
- cs[i] = devm_gpiod_get_index_optional(dev, "cs", i,
- GPIOD_OUT_LOW);
- if (IS_ERR(cs[i]))
- return PTR_ERR(cs[i]);
- if (cs[i]) {
- /*
- * If we find a CS GPIO, name it after the device and
- * chip select line.
- */
- char *gpioname;
- gpioname = devm_kasprintf(dev, GFP_KERNEL, "%s CS%d",
- dev_name(dev), i);
- if (!gpioname)
- return -ENOMEM;
- gpiod_set_consumer_name(cs[i], gpioname);
- num_cs_gpios++;
- continue;
- }
- if (ctlr->max_native_cs && i >= ctlr->max_native_cs) {
- dev_err(dev, "Invalid native chip select %d\n", i);
- return -EINVAL;
- }
- native_cs_mask |= BIT(i);
- }
- ctlr->unused_native_cs = ffs(~native_cs_mask) - 1;
- if ((ctlr->flags & SPI_MASTER_GPIO_SS) && num_cs_gpios &&
- ctlr->max_native_cs && ctlr->unused_native_cs >= ctlr->max_native_cs) {
- dev_err(dev, "No unused native chip select available\n");
- return -EINVAL;
- }
- return 0;
- }
- static int spi_controller_check_ops(struct spi_controller *ctlr)
- {
- /*
- * The controller may implement only the high-level SPI-memory like
- * operations if it does not support regular SPI transfers, and this is
- * valid use case.
- * If ->mem_ops is NULL, we request that at least one of the
- * ->transfer_xxx() method be implemented.
- */
- if (ctlr->mem_ops) {
- if (!ctlr->mem_ops->exec_op)
- return -EINVAL;
- } else if (!ctlr->transfer && !ctlr->transfer_one &&
- !ctlr->transfer_one_message) {
- return -EINVAL;
- }
- return 0;
- }
- /**
- * spi_register_controller - register SPI master or slave controller
- * @ctlr: initialized master, originally from spi_alloc_master() or
- * spi_alloc_slave()
- * Context: can sleep
- *
- * SPI controllers connect to their drivers using some non-SPI bus,
- * such as the platform bus. The final stage of probe() in that code
- * includes calling spi_register_controller() to hook up to this SPI bus glue.
- *
- * SPI controllers use board specific (often SOC specific) bus numbers,
- * and board-specific addressing for SPI devices combines those numbers
- * with chip select numbers. Since SPI does not directly support dynamic
- * device identification, boards need configuration tables telling which
- * chip is at which address.
- *
- * This must be called from context that can sleep. It returns zero on
- * success, else a negative error code (dropping the controller's refcount).
- * After a successful return, the caller is responsible for calling
- * spi_unregister_controller().
- *
- * Return: zero on success, else a negative error code.
- */
- int spi_register_controller(struct spi_controller *ctlr)
- {
- struct device *dev = ctlr->dev.parent;
- struct boardinfo *bi;
- int status;
- int id, first_dynamic;
- if (!dev)
- return -ENODEV;
- /*
- * Make sure all necessary hooks are implemented before registering
- * the SPI controller.
- */
- status = spi_controller_check_ops(ctlr);
- if (status)
- return status;
- if (ctlr->bus_num >= 0) {
- /* devices with a fixed bus num must check-in with the num */
- mutex_lock(&board_lock);
- id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
- ctlr->bus_num + 1, GFP_KERNEL);
- mutex_unlock(&board_lock);
- if (WARN(id < 0, "couldn't get idr"))
- return id == -ENOSPC ? -EBUSY : id;
- ctlr->bus_num = id;
- } else if (ctlr->dev.of_node) {
- /* allocate dynamic bus number using Linux idr */
- id = of_alias_get_id(ctlr->dev.of_node, "spi");
- if (id >= 0) {
- ctlr->bus_num = id;
- mutex_lock(&board_lock);
- id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
- ctlr->bus_num + 1, GFP_KERNEL);
- mutex_unlock(&board_lock);
- if (WARN(id < 0, "couldn't get idr"))
- return id == -ENOSPC ? -EBUSY : id;
- }
- }
- if (ctlr->bus_num < 0) {
- first_dynamic = of_alias_get_highest_id("spi");
- if (first_dynamic < 0)
- first_dynamic = 0;
- else
- first_dynamic++;
- mutex_lock(&board_lock);
- id = idr_alloc(&spi_master_idr, ctlr, first_dynamic,
- 0, GFP_KERNEL);
- mutex_unlock(&board_lock);
- if (WARN(id < 0, "couldn't get idr"))
- return id;
- ctlr->bus_num = id;
- }
- INIT_LIST_HEAD(&ctlr->queue);
- spin_lock_init(&ctlr->queue_lock);
- spin_lock_init(&ctlr->bus_lock_spinlock);
- mutex_init(&ctlr->bus_lock_mutex);
- mutex_init(&ctlr->io_mutex);
- ctlr->bus_lock_flag = 0;
- init_completion(&ctlr->xfer_completion);
- if (!ctlr->max_dma_len)
- ctlr->max_dma_len = INT_MAX;
- /* register the device, then userspace will see it.
- * registration fails if the bus ID is in use.
- */
- dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num);
- if (!spi_controller_is_slave(ctlr)) {
- if (ctlr->use_gpio_descriptors) {
- status = spi_get_gpio_descs(ctlr);
- if (status)
- goto free_bus_id;
- /*
- * A controller using GPIO descriptors always
- * supports SPI_CS_HIGH if need be.
- */
- ctlr->mode_bits |= SPI_CS_HIGH;
- } else {
- /* Legacy code path for GPIOs from DT */
- status = of_spi_get_gpio_numbers(ctlr);
- if (status)
- goto free_bus_id;
- }
- }
- /*
- * Even if it's just one always-selected device, there must
- * be at least one chipselect.
- */
- if (!ctlr->num_chipselect) {
- status = -EINVAL;
- goto free_bus_id;
- }
- status = device_add(&ctlr->dev);
- if (status < 0)
- goto free_bus_id;
- dev_dbg(dev, "registered %s %s\n",
- spi_controller_is_slave(ctlr) ? "slave" : "master",
- dev_name(&ctlr->dev));
- /*
- * If we're using a queued driver, start the queue. Note that we don't
- * need the queueing logic if the driver is only supporting high-level
- * memory operations.
- */
- if (ctlr->transfer) {
- dev_info(dev, "controller is unqueued, this is deprecated\n");
- } else if (ctlr->transfer_one || ctlr->transfer_one_message) {
- status = spi_controller_initialize_queue(ctlr);
- if (status) {
- device_del(&ctlr->dev);
- goto free_bus_id;
- }
- }
- /* add statistics */
- spin_lock_init(&ctlr->statistics.lock);
- mutex_lock(&board_lock);
- list_add_tail(&ctlr->list, &spi_controller_list);
- list_for_each_entry(bi, &board_list, list)
- spi_match_controller_to_boardinfo(ctlr, &bi->board_info);
- mutex_unlock(&board_lock);
- /* Register devices from the device tree and ACPI */
- of_register_spi_devices(ctlr);
- acpi_register_spi_devices(ctlr);
- return status;
- free_bus_id:
- mutex_lock(&board_lock);
- idr_remove(&spi_master_idr, ctlr->bus_num);
- mutex_unlock(&board_lock);
- return status;
- }
- EXPORT_SYMBOL_GPL(spi_register_controller);
- static void devm_spi_unregister(struct device *dev, void *res)
- {
- spi_unregister_controller(*(struct spi_controller **)res);
- }
- /**
- * devm_spi_register_controller - register managed SPI master or slave
- * controller
- * @dev: device managing SPI controller
- * @ctlr: initialized controller, originally from spi_alloc_master() or
- * spi_alloc_slave()
- * Context: can sleep
- *
- * Register a SPI device as with spi_register_controller() which will
- * automatically be unregistered and freed.
- *
- * Return: zero on success, else a negative error code.
- */
- int devm_spi_register_controller(struct device *dev,
- struct spi_controller *ctlr)
- {
- struct spi_controller **ptr;
- int ret;
- ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
- if (!ptr)
- return -ENOMEM;
- ret = spi_register_controller(ctlr);
- if (!ret) {
- *ptr = ctlr;
- devres_add(dev, ptr);
- } else {
- devres_free(ptr);
- }
- return ret;
- }
- EXPORT_SYMBOL_GPL(devm_spi_register_controller);
- static int devm_spi_match_controller(struct device *dev, void *res, void *ctlr)
- {
- return *(struct spi_controller **)res == ctlr;
- }
- static int __unregister(struct device *dev, void *null)
- {
- spi_unregister_device(to_spi_device(dev));
- return 0;
- }
- /**
- * spi_unregister_controller - unregister SPI master or slave controller
- * @ctlr: the controller being unregistered
- * Context: can sleep
- *
- * This call is used only by SPI controller drivers, which are the
- * only ones directly touching chip registers.
- *
- * This must be called from context that can sleep.
- *
- * Note that this function also drops a reference to the controller.
- */
- void spi_unregister_controller(struct spi_controller *ctlr)
- {
- struct spi_controller *found;
- int id = ctlr->bus_num;
- /* Prevent addition of new devices, unregister existing ones */
- if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
- mutex_lock(&spi_add_lock);
- device_for_each_child(&ctlr->dev, NULL, __unregister);
- /* First make sure that this controller was ever added */
- mutex_lock(&board_lock);
- found = idr_find(&spi_master_idr, id);
- mutex_unlock(&board_lock);
- if (ctlr->queued) {
- if (spi_destroy_queue(ctlr))
- dev_err(&ctlr->dev, "queue remove failed\n");
- }
- mutex_lock(&board_lock);
- list_del(&ctlr->list);
- mutex_unlock(&board_lock);
- device_del(&ctlr->dev);
- /* Release the last reference on the controller if its driver
- * has not yet been converted to devm_spi_alloc_master/slave().
- */
- if (!devres_find(ctlr->dev.parent, devm_spi_release_controller,
- devm_spi_match_controller, ctlr))
- put_device(&ctlr->dev);
- /* free bus id */
- mutex_lock(&board_lock);
- if (found == ctlr)
- idr_remove(&spi_master_idr, id);
- mutex_unlock(&board_lock);
- if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
- mutex_unlock(&spi_add_lock);
- }
- EXPORT_SYMBOL_GPL(spi_unregister_controller);
- int spi_controller_suspend(struct spi_controller *ctlr)
- {
- int ret;
- /* Basically no-ops for non-queued controllers */
- if (!ctlr->queued)
- return 0;
- ret = spi_stop_queue(ctlr);
- if (ret)
- dev_err(&ctlr->dev, "queue stop failed\n");
- return ret;
- }
- EXPORT_SYMBOL_GPL(spi_controller_suspend);
- int spi_controller_resume(struct spi_controller *ctlr)
- {
- int ret;
- if (!ctlr->queued)
- return 0;
- ret = spi_start_queue(ctlr);
- if (ret)
- dev_err(&ctlr->dev, "queue restart failed\n");
- return ret;
- }
- EXPORT_SYMBOL_GPL(spi_controller_resume);
- static int __spi_controller_match(struct device *dev, const void *data)
- {
- struct spi_controller *ctlr;
- const u16 *bus_num = data;
- ctlr = container_of(dev, struct spi_controller, dev);
- return ctlr->bus_num == *bus_num;
- }
- /**
- * spi_busnum_to_master - look up master associated with bus_num
- * @bus_num: the master's bus number
- * Context: can sleep
- *
- * This call may be used with devices that are registered after
- * arch init time. It returns a refcounted pointer to the relevant
- * spi_controller (which the caller must release), or NULL if there is
- * no such master registered.
- *
- * Return: the SPI master structure on success, else NULL.
- */
- struct spi_controller *spi_busnum_to_master(u16 bus_num)
- {
- struct device *dev;
- struct spi_controller *ctlr = NULL;
- dev = class_find_device(&spi_master_class, NULL, &bus_num,
- __spi_controller_match);
- if (dev)
- ctlr = container_of(dev, struct spi_controller, dev);
- /* reference got in class_find_device */
- return ctlr;
- }
- EXPORT_SYMBOL_GPL(spi_busnum_to_master);
- /*-------------------------------------------------------------------------*/
- /* Core methods for SPI resource management */
- /**
- * spi_res_alloc - allocate a spi resource that is life-cycle managed
- * during the processing of a spi_message while using
- * spi_transfer_one
- * @spi: the spi device for which we allocate memory
- * @release: the release code to execute for this resource
- * @size: size to alloc and return
- * @gfp: GFP allocation flags
- *
- * Return: the pointer to the allocated data
- *
- * This may get enhanced in the future to allocate from a memory pool
- * of the @spi_device or @spi_controller to avoid repeated allocations.
- */
- void *spi_res_alloc(struct spi_device *spi,
- spi_res_release_t release,
- size_t size, gfp_t gfp)
- {
- struct spi_res *sres;
- sres = kzalloc(sizeof(*sres) + size, gfp);
- if (!sres)
- return NULL;
- INIT_LIST_HEAD(&sres->entry);
- sres->release = release;
- return sres->data;
- }
- EXPORT_SYMBOL_GPL(spi_res_alloc);
- /**
- * spi_res_free - free an spi resource
- * @res: pointer to the custom data of a resource
- *
- */
- void spi_res_free(void *res)
- {
- struct spi_res *sres = container_of(res, struct spi_res, data);
- if (!res)
- return;
- WARN_ON(!list_empty(&sres->entry));
- kfree(sres);
- }
- EXPORT_SYMBOL_GPL(spi_res_free);
- /**
- * spi_res_add - add a spi_res to the spi_message
- * @message: the spi message
- * @res: the spi_resource
- */
- void spi_res_add(struct spi_message *message, void *res)
- {
- struct spi_res *sres = container_of(res, struct spi_res, data);
- WARN_ON(!list_empty(&sres->entry));
- list_add_tail(&sres->entry, &message->resources);
- }
- EXPORT_SYMBOL_GPL(spi_res_add);
- /**
- * spi_res_release - release all spi resources for this message
- * @ctlr: the @spi_controller
- * @message: the @spi_message
- */
- void spi_res_release(struct spi_controller *ctlr, struct spi_message *message)
- {
- struct spi_res *res, *tmp;
- list_for_each_entry_safe_reverse(res, tmp, &message->resources, entry) {
- if (res->release)
- res->release(ctlr, message, res->data);
- list_del(&res->entry);
- kfree(res);
- }
- }
- EXPORT_SYMBOL_GPL(spi_res_release);
- /*-------------------------------------------------------------------------*/
- /* Core methods for spi_message alterations */
- static void __spi_replace_transfers_release(struct spi_controller *ctlr,
- struct spi_message *msg,
- void *res)
- {
- struct spi_replaced_transfers *rxfer = res;
- size_t i;
- /* call extra callback if requested */
- if (rxfer->release)
- rxfer->release(ctlr, msg, res);
- /* insert replaced transfers back into the message */
- list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
- /* remove the formerly inserted entries */
- for (i = 0; i < rxfer->inserted; i++)
- list_del(&rxfer->inserted_transfers[i].transfer_list);
- }
- /**
- * spi_replace_transfers - replace transfers with several transfers
- * and register change with spi_message.resources
- * @msg: the spi_message we work upon
- * @xfer_first: the first spi_transfer we want to replace
- * @remove: number of transfers to remove
- * @insert: the number of transfers we want to insert instead
- * @release: extra release code necessary in some circumstances
- * @extradatasize: extra data to allocate (with alignment guarantees
- * of struct @spi_transfer)
- * @gfp: gfp flags
- *
- * Returns: pointer to @spi_replaced_transfers,
- * PTR_ERR(...) in case of errors.
- */
- struct spi_replaced_transfers *spi_replace_transfers(
- struct spi_message *msg,
- struct spi_transfer *xfer_first,
- size_t remove,
- size_t insert,
- spi_replaced_release_t release,
- size_t extradatasize,
- gfp_t gfp)
- {
- struct spi_replaced_transfers *rxfer;
- struct spi_transfer *xfer;
- size_t i;
- /* allocate the structure using spi_res */
- rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
- struct_size(rxfer, inserted_transfers, insert)
- + extradatasize,
- gfp);
- if (!rxfer)
- return ERR_PTR(-ENOMEM);
- /* the release code to invoke before running the generic release */
- rxfer->release = release;
- /* assign extradata */
- if (extradatasize)
- rxfer->extradata =
- &rxfer->inserted_transfers[insert];
- /* init the replaced_transfers list */
- INIT_LIST_HEAD(&rxfer->replaced_transfers);
- /* assign the list_entry after which we should reinsert
- * the @replaced_transfers - it may be spi_message.messages!
- */
- rxfer->replaced_after = xfer_first->transfer_list.prev;
- /* remove the requested number of transfers */
- for (i = 0; i < remove; i++) {
- /* if the entry after replaced_after it is msg->transfers
- * then we have been requested to remove more transfers
- * than are in the list
- */
- if (rxfer->replaced_after->next == &msg->transfers) {
- dev_err(&msg->spi->dev,
- "requested to remove more spi_transfers than are available\n");
- /* insert replaced transfers back into the message */
- list_splice(&rxfer->replaced_transfers,
- rxfer->replaced_after);
- /* free the spi_replace_transfer structure */
- spi_res_free(rxfer);
- /* and return with an error */
- return ERR_PTR(-EINVAL);
- }
- /* remove the entry after replaced_after from list of
- * transfers and add it to list of replaced_transfers
- */
- list_move_tail(rxfer->replaced_after->next,
- &rxfer->replaced_transfers);
- }
- /* create copy of the given xfer with identical settings
- * based on the first transfer to get removed
- */
- for (i = 0; i < insert; i++) {
- /* we need to run in reverse order */
- xfer = &rxfer->inserted_transfers[insert - 1 - i];
- /* copy all spi_transfer data */
- memcpy(xfer, xfer_first, sizeof(*xfer));
- /* add to list */
- list_add(&xfer->transfer_list, rxfer->replaced_after);
- /* clear cs_change and delay for all but the last */
- if (i) {
- xfer->cs_change = false;
- xfer->delay_usecs = 0;
- xfer->delay.value = 0;
- }
- }
- /* set up inserted */
- rxfer->inserted = insert;
- /* and register it with spi_res/spi_message */
- spi_res_add(msg, rxfer);
- return rxfer;
- }
- EXPORT_SYMBOL_GPL(spi_replace_transfers);
- static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
- struct spi_message *msg,
- struct spi_transfer **xferp,
- size_t maxsize,
- gfp_t gfp)
- {
- struct spi_transfer *xfer = *xferp, *xfers;
- struct spi_replaced_transfers *srt;
- size_t offset;
- size_t count, i;
- /* calculate how many we have to replace */
- count = DIV_ROUND_UP(xfer->len, maxsize);
- /* create replacement */
- srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
- if (IS_ERR(srt))
- return PTR_ERR(srt);
- xfers = srt->inserted_transfers;
- /* now handle each of those newly inserted spi_transfers
- * note that the replacements spi_transfers all are preset
- * to the same values as *xferp, so tx_buf, rx_buf and len
- * are all identical (as well as most others)
- * so we just have to fix up len and the pointers.
- *
- * this also includes support for the depreciated
- * spi_message.is_dma_mapped interface
- */
- /* the first transfer just needs the length modified, so we
- * run it outside the loop
- */
- xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
- /* all the others need rx_buf/tx_buf also set */
- for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
- /* update rx_buf, tx_buf and dma */
- if (xfers[i].rx_buf)
- xfers[i].rx_buf += offset;
- if (xfers[i].rx_dma)
- xfers[i].rx_dma += offset;
- if (xfers[i].tx_buf)
- xfers[i].tx_buf += offset;
- if (xfers[i].tx_dma)
- xfers[i].tx_dma += offset;
- /* update length */
- xfers[i].len = min(maxsize, xfers[i].len - offset);
- }
- /* we set up xferp to the last entry we have inserted,
- * so that we skip those already split transfers
- */
- *xferp = &xfers[count - 1];
- /* increment statistics counters */
- SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
- transfers_split_maxsize);
- SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
- transfers_split_maxsize);
- return 0;
- }
- /**
- * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
- * when an individual transfer exceeds a
- * certain size
- * @ctlr: the @spi_controller for this transfer
- * @msg: the @spi_message to transform
- * @maxsize: the maximum when to apply this
- * @gfp: GFP allocation flags
- *
- * Return: status of transformation
- */
- int spi_split_transfers_maxsize(struct spi_controller *ctlr,
- struct spi_message *msg,
- size_t maxsize,
- gfp_t gfp)
- {
- struct spi_transfer *xfer;
- int ret;
- /* iterate over the transfer_list,
- * but note that xfer is advanced to the last transfer inserted
- * to avoid checking sizes again unnecessarily (also xfer does
- * potentiall belong to a different list by the time the
- * replacement has happened
- */
- list_for_each_entry(xfer, &msg->transfers, transfer_list) {
- if (xfer->len > maxsize) {
- ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,
- maxsize, gfp);
- if (ret)
- return ret;
- }
- }
- return 0;
- }
- EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
- /*-------------------------------------------------------------------------*/
- /* Core methods for SPI controller protocol drivers. Some of the
- * other core methods are currently defined as inline functions.
- */
- static int __spi_validate_bits_per_word(struct spi_controller *ctlr,
- u8 bits_per_word)
- {
- if (ctlr->bits_per_word_mask) {
- /* Only 32 bits fit in the mask */
- if (bits_per_word > 32)
- return -EINVAL;
- if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word)))
- return -EINVAL;
- }
- return 0;
- }
- /**
- * spi_setup - setup SPI mode and clock rate
- * @spi: the device whose settings are being modified
- * Context: can sleep, and no requests are queued to the device
- *
- * SPI protocol drivers may need to update the transfer mode if the
- * device doesn't work with its default. They may likewise need
- * to update clock rates or word sizes from initial values. This function
- * changes those settings, and must be called from a context that can sleep.
- * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
- * effect the next time the device is selected and data is transferred to
- * or from it. When this function returns, the spi device is deselected.
- *
- * Note that this call will fail if the protocol driver specifies an option
- * that the underlying controller or its driver does not support. For
- * example, not all hardware supports wire transfers using nine bit words,
- * LSB-first wire encoding, or active-high chipselects.
- *
- * Return: zero on success, else a negative error code.
- */
- int spi_setup(struct spi_device *spi)
- {
- unsigned bad_bits, ugly_bits;
- int status;
- /* check mode to prevent that DUAL and QUAD set at the same time
- */
- if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
- ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
- dev_err(&spi->dev,
- "setup: can not select dual and quad at the same time\n");
- return -EINVAL;
- }
- /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
- */
- if ((spi->mode & SPI_3WIRE) && (spi->mode &
- (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
- SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))
- return -EINVAL;
- /* help drivers fail *cleanly* when they need options
- * that aren't supported with their current controller
- * SPI_CS_WORD has a fallback software implementation,
- * so it is ignored here.
- */
- bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD);
- /* nothing prevents from working with active-high CS in case if it
- * is driven by GPIO.
- */
- if (gpio_is_valid(spi->cs_gpio))
- bad_bits &= ~SPI_CS_HIGH;
- ugly_bits = bad_bits &
- (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
- SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL);
- if (ugly_bits) {
- dev_warn(&spi->dev,
- "setup: ignoring unsupported mode bits %x\n",
- ugly_bits);
- spi->mode &= ~ugly_bits;
- bad_bits &= ~ugly_bits;
- }
- if (bad_bits) {
- dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
- bad_bits);
- return -EINVAL;
- }
- if (!spi->bits_per_word)
- spi->bits_per_word = 8;
- status = __spi_validate_bits_per_word(spi->controller,
- spi->bits_per_word);
- if (status)
- return status;
- if (!spi->max_speed_hz)
- spi->max_speed_hz = spi->controller->max_speed_hz;
- mutex_lock(&spi->controller->io_mutex);
- if (spi->controller->setup)
- status = spi->controller->setup(spi);
- if (spi->controller->auto_runtime_pm && spi->controller->set_cs) {
- status = pm_runtime_get_sync(spi->controller->dev.parent);
- if (status < 0) {
- mutex_unlock(&spi->controller->io_mutex);
- pm_runtime_put_noidle(spi->controller->dev.parent);
- dev_err(&spi->controller->dev, "Failed to power device: %d\n",
- status);
- return status;
- }
- /*
- * We do not want to return positive value from pm_runtime_get,
- * there are many instances of devices calling spi_setup() and
- * checking for a non-zero return value instead of a negative
- * return value.
- */
- status = 0;
- spi_set_cs(spi, false, true);
- pm_runtime_mark_last_busy(spi->controller->dev.parent);
- pm_runtime_put_autosuspend(spi->controller->dev.parent);
- } else {
- spi_set_cs(spi, false, true);
- }
- mutex_unlock(&spi->controller->io_mutex);
- if (spi->rt && !spi->controller->rt) {
- spi->controller->rt = true;
- spi_set_thread_rt(spi->controller);
- }
- dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
- (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
- (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
- (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
- (spi->mode & SPI_3WIRE) ? "3wire, " : "",
- (spi->mode & SPI_LOOP) ? "loopback, " : "",
- spi->bits_per_word, spi->max_speed_hz,
- status);
- return status;
- }
- EXPORT_SYMBOL_GPL(spi_setup);
- /**
- * spi_set_cs_timing - configure CS setup, hold, and inactive delays
- * @spi: the device that requires specific CS timing configuration
- * @setup: CS setup time specified via @spi_delay
- * @hold: CS hold time specified via @spi_delay
- * @inactive: CS inactive delay between transfers specified via @spi_delay
- *
- * Return: zero on success, else a negative error code.
- */
- int spi_set_cs_timing(struct spi_device *spi, struct spi_delay *setup,
- struct spi_delay *hold, struct spi_delay *inactive)
- {
- size_t len;
- if (spi->controller->set_cs_timing)
- return spi->controller->set_cs_timing(spi, setup, hold,
- inactive);
- if ((setup && setup->unit == SPI_DELAY_UNIT_SCK) ||
- (hold && hold->unit == SPI_DELAY_UNIT_SCK) ||
- (inactive && inactive->unit == SPI_DELAY_UNIT_SCK)) {
- dev_err(&spi->dev,
- "Clock-cycle delays for CS not supported in SW mode\n");
- return -ENOTSUPP;
- }
- len = sizeof(struct spi_delay);
- /* copy delays to controller */
- if (setup)
- memcpy(&spi->controller->cs_setup, setup, len);
- else
- memset(&spi->controller->cs_setup, 0, len);
- if (hold)
- memcpy(&spi->controller->cs_hold, hold, len);
- else
- memset(&spi->controller->cs_hold, 0, len);
- if (inactive)
- memcpy(&spi->controller->cs_inactive, inactive, len);
- else
- memset(&spi->controller->cs_inactive, 0, len);
- return 0;
- }
- EXPORT_SYMBOL_GPL(spi_set_cs_timing);
- static int _spi_xfer_word_delay_update(struct spi_transfer *xfer,
- struct spi_device *spi)
- {
- int delay1, delay2;
- delay1 = spi_delay_to_ns(&xfer->word_delay, xfer);
- if (delay1 < 0)
- return delay1;
- delay2 = spi_delay_to_ns(&spi->word_delay, xfer);
- if (delay2 < 0)
- return delay2;
- if (delay1 < delay2)
- memcpy(&xfer->word_delay, &spi->word_delay,
- sizeof(xfer->word_delay));
- return 0;
- }
- static int __spi_validate(struct spi_device *spi, struct spi_message *message)
- {
- struct spi_controller *ctlr = spi->controller;
- struct spi_transfer *xfer;
- int w_size;
- if (list_empty(&message->transfers))
- return -EINVAL;
- /* If an SPI controller does not support toggling the CS line on each
- * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO
- * for the CS line, we can emulate the CS-per-word hardware function by
- * splitting transfers into one-word transfers and ensuring that
- * cs_change is set for each transfer.
- */
- if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) ||
- spi->cs_gpiod ||
- gpio_is_valid(spi->cs_gpio))) {
- size_t maxsize;
- int ret;
- maxsize = (spi->bits_per_word + 7) / 8;
- /* spi_split_transfers_maxsize() requires message->spi */
- message->spi = spi;
- ret = spi_split_transfers_maxsize(ctlr, message, maxsize,
- GFP_KERNEL);
- if (ret)
- return ret;
- list_for_each_entry(xfer, &message->transfers, transfer_list) {
- /* don't change cs_change on the last entry in the list */
- if (list_is_last(&xfer->transfer_list, &message->transfers))
- break;
- xfer->cs_change = 1;
- }
- }
- /* Half-duplex links include original MicroWire, and ones with
- * only one data pin like SPI_3WIRE (switches direction) or where
- * either MOSI or MISO is missing. They can also be caused by
- * software limitations.
- */
- if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) ||
- (spi->mode & SPI_3WIRE)) {
- unsigned flags = ctlr->flags;
- list_for_each_entry(xfer, &message->transfers, transfer_list) {
- if (xfer->rx_buf && xfer->tx_buf)
- return -EINVAL;
- if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf)
- return -EINVAL;
- if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf)
- return -EINVAL;
- }
- }
- /**
- * Set transfer bits_per_word and max speed as spi device default if
- * it is not set for this transfer.
- * Set transfer tx_nbits and rx_nbits as single transfer default
- * (SPI_NBITS_SINGLE) if it is not set for this transfer.
- * Ensure transfer word_delay is at least as long as that required by
- * device itself.
- */
- message->frame_length = 0;
- list_for_each_entry(xfer, &message->transfers, transfer_list) {
- xfer->effective_speed_hz = 0;
- message->frame_length += xfer->len;
- if (!xfer->bits_per_word)
- xfer->bits_per_word = spi->bits_per_word;
- if (!xfer->speed_hz)
- xfer->speed_hz = spi->max_speed_hz;
- if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz)
- xfer->speed_hz = ctlr->max_speed_hz;
- if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word))
- return -EINVAL;
- /*
- * SPI transfer length should be multiple of SPI word size
- * where SPI word size should be power-of-two multiple
- */
- if (xfer->bits_per_word <= 8)
- w_size = 1;
- else if (xfer->bits_per_word <= 16)
- w_size = 2;
- else
- w_size = 4;
- /* No partial transfers accepted */
- if (xfer->len % w_size)
- return -EINVAL;
- if (xfer->speed_hz && ctlr->min_speed_hz &&
- xfer->speed_hz < ctlr->min_speed_hz)
- return -EINVAL;
- if (xfer->tx_buf && !xfer->tx_nbits)
- xfer->tx_nbits = SPI_NBITS_SINGLE;
- if (xfer->rx_buf && !xfer->rx_nbits)
- xfer->rx_nbits = SPI_NBITS_SINGLE;
- /* check transfer tx/rx_nbits:
- * 1. check the value matches one of single, dual and quad
- * 2. check tx/rx_nbits match the mode in spi_device
- */
- if (xfer->tx_buf) {
- if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
- xfer->tx_nbits != SPI_NBITS_DUAL &&
- xfer->tx_nbits != SPI_NBITS_QUAD)
- return -EINVAL;
- if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
- !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
- return -EINVAL;
- if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
- !(spi->mode & SPI_TX_QUAD))
- return -EINVAL;
- }
- /* check transfer rx_nbits */
- if (xfer->rx_buf) {
- if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
- xfer->rx_nbits != SPI_NBITS_DUAL &&
- xfer->rx_nbits != SPI_NBITS_QUAD)
- return -EINVAL;
- if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
- !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
- return -EINVAL;
- if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
- !(spi->mode & SPI_RX_QUAD))
- return -EINVAL;
- }
- if (_spi_xfer_word_delay_update(xfer, spi))
- return -EINVAL;
- }
- message->status = -EINPROGRESS;
- return 0;
- }
- static int __spi_async(struct spi_device *spi, struct spi_message *message)
- {
- struct spi_controller *ctlr = spi->controller;
- struct spi_transfer *xfer;
- /*
- * Some controllers do not support doing regular SPI transfers. Return
- * ENOTSUPP when this is the case.
- */
- if (!ctlr->transfer)
- return -ENOTSUPP;
- message->spi = spi;
- SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async);
- SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
- trace_spi_message_submit(message);
- if (!ctlr->ptp_sts_supported) {
- list_for_each_entry(xfer, &message->transfers, transfer_list) {
- xfer->ptp_sts_word_pre = 0;
- ptp_read_system_prets(xfer->ptp_sts);
- }
- }
- return ctlr->transfer(spi, message);
- }
- /**
- * spi_async - asynchronous SPI transfer
- * @spi: device with which data will be exchanged
- * @message: describes the data transfers, including completion callback
- * Context: any (irqs may be blocked, etc)
- *
- * This call may be used in_irq and other contexts which can't sleep,
- * as well as from task contexts which can sleep.
- *
- * The completion callback is invoked in a context which can't sleep.
- * Before that invocation, the value of message->status is undefined.
- * When the callback is issued, message->status holds either zero (to
- * indicate complete success) or a negative error code. After that
- * callback returns, the driver which issued the transfer request may
- * deallocate the associated memory; it's no longer in use by any SPI
- * core or controller driver code.
- *
- * Note that although all messages to a spi_device are handled in
- * FIFO order, messages may go to different devices in other orders.
- * Some device might be higher priority, or have various "hard" access
- * time requirements, for example.
- *
- * On detection of any fault during the transfer, processing of
- * the entire message is aborted, and the device is deselected.
- * Until returning from the associated message completion callback,
- * no other spi_message queued to that device will be processed.
- * (This rule applies equally to all the synchronous transfer calls,
- * which are wrappers around this core asynchronous primitive.)
- *
- * Return: zero on success, else a negative error code.
- */
- int spi_async(struct spi_device *spi, struct spi_message *message)
- {
- struct spi_controller *ctlr = spi->controller;
- int ret;
- unsigned long flags;
- ret = __spi_validate(spi, message);
- if (ret != 0)
- return ret;
- spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
- if (ctlr->bus_lock_flag)
- ret = -EBUSY;
- else
- ret = __spi_async(spi, message);
- spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
- return ret;
- }
- EXPORT_SYMBOL_GPL(spi_async);
- /**
- * spi_async_locked - version of spi_async with exclusive bus usage
- * @spi: device with which data will be exchanged
- * @message: describes the data transfers, including completion callback
- * Context: any (irqs may be blocked, etc)
- *
- * This call may be used in_irq and other contexts which can't sleep,
- * as well as from task contexts which can sleep.
- *
- * The completion callback is invoked in a context which can't sleep.
- * Before that invocation, the value of message->status is undefined.
- * When the callback is issued, message->status holds either zero (to
- * indicate complete success) or a negative error code. After that
- * callback returns, the driver which issued the transfer request may
- * deallocate the associated memory; it's no longer in use by any SPI
- * core or controller driver code.
- *
- * Note that although all messages to a spi_device are handled in
- * FIFO order, messages may go to different devices in other orders.
- * Some device might be higher priority, or have various "hard" access
- * time requirements, for example.
- *
- * On detection of any fault during the transfer, processing of
- * the entire message is aborted, and the device is deselected.
- * Until returning from the associated message completion callback,
- * no other spi_message queued to that device will be processed.
- * (This rule applies equally to all the synchronous transfer calls,
- * which are wrappers around this core asynchronous primitive.)
- *
- * Return: zero on success, else a negative error code.
- */
- int spi_async_locked(struct spi_device *spi, struct spi_message *message)
- {
- struct spi_controller *ctlr = spi->controller;
- int ret;
- unsigned long flags;
- ret = __spi_validate(spi, message);
- if (ret != 0)
- return ret;
- spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
- ret = __spi_async(spi, message);
- spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
- return ret;
- }
- EXPORT_SYMBOL_GPL(spi_async_locked);
- /*-------------------------------------------------------------------------*/
- /* Utility methods for SPI protocol drivers, layered on
- * top of the core. Some other utility methods are defined as
- * inline functions.
- */
- static void spi_complete(void *arg)
- {
- complete(arg);
- }
- static int __spi_sync(struct spi_device *spi, struct spi_message *message)
- {
- DECLARE_COMPLETION_ONSTACK(done);
- int status;
- struct spi_controller *ctlr = spi->controller;
- unsigned long flags;
- status = __spi_validate(spi, message);
- if (status != 0)
- return status;
- message->complete = spi_complete;
- message->context = &done;
- message->spi = spi;
- SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_sync);
- SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
- /* If we're not using the legacy transfer method then we will
- * try to transfer in the calling context so special case.
- * This code would be less tricky if we could remove the
- * support for driver implemented message queues.
- */
- if (ctlr->transfer == spi_queued_transfer) {
- spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
- trace_spi_message_submit(message);
- status = __spi_queued_transfer(spi, message, false);
- spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
- } else {
- status = spi_async_locked(spi, message);
- }
- if (status == 0) {
- /* Push out the messages in the calling context if we
- * can.
- */
- if (ctlr->transfer == spi_queued_transfer) {
- SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
- spi_sync_immediate);
- SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
- spi_sync_immediate);
- __spi_pump_messages(ctlr, false);
- }
- wait_for_completion(&done);
- status = message->status;
- }
- message->context = NULL;
- return status;
- }
- /**
- * spi_sync - blocking/synchronous SPI data transfers
- * @spi: device with which data will be exchanged
- * @message: describes the data transfers
- * Context: can sleep
- *
- * This call may only be used from a context that may sleep. The sleep
- * is non-interruptible, and has no timeout. Low-overhead controller
- * drivers may DMA directly into and out of the message buffers.
- *
- * Note that the SPI device's chip select is active during the message,
- * and then is normally disabled between messages. Drivers for some
- * frequently-used devices may want to minimize costs of selecting a chip,
- * by leaving it selected in anticipation that the next message will go
- * to the same chip. (That may increase power usage.)
- *
- * Also, the caller is guaranteeing that the memory associated with the
- * message will not be freed before this call returns.
- *
- * Return: zero on success, else a negative error code.
- */
- int spi_sync(struct spi_device *spi, struct spi_message *message)
- {
- int ret;
- mutex_lock(&spi->controller->bus_lock_mutex);
- ret = __spi_sync(spi, message);
- mutex_unlock(&spi->controller->bus_lock_mutex);
- return ret;
- }
- EXPORT_SYMBOL_GPL(spi_sync);
- /**
- * spi_sync_locked - version of spi_sync with exclusive bus usage
- * @spi: device with which data will be exchanged
- * @message: describes the data transfers
- * Context: can sleep
- *
- * This call may only be used from a context that may sleep. The sleep
- * is non-interruptible, and has no timeout. Low-overhead controller
- * drivers may DMA directly into and out of the message buffers.
- *
- * This call should be used by drivers that require exclusive access to the
- * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
- * be released by a spi_bus_unlock call when the exclusive access is over.
- *
- * Return: zero on success, else a negative error code.
- */
- int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
- {
- return __spi_sync(spi, message);
- }
- EXPORT_SYMBOL_GPL(spi_sync_locked);
- /**
- * spi_bus_lock - obtain a lock for exclusive SPI bus usage
- * @ctlr: SPI bus master that should be locked for exclusive bus access
- * Context: can sleep
- *
- * This call may only be used from a context that may sleep. The sleep
- * is non-interruptible, and has no timeout.
- *
- * This call should be used by drivers that require exclusive access to the
- * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
- * exclusive access is over. Data transfer must be done by spi_sync_locked
- * and spi_async_locked calls when the SPI bus lock is held.
- *
- * Return: always zero.
- */
- int spi_bus_lock(struct spi_controller *ctlr)
- {
- unsigned long flags;
- mutex_lock(&ctlr->bus_lock_mutex);
- spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
- ctlr->bus_lock_flag = 1;
- spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
- /* mutex remains locked until spi_bus_unlock is called */
- return 0;
- }
- EXPORT_SYMBOL_GPL(spi_bus_lock);
- /**
- * spi_bus_unlock - release the lock for exclusive SPI bus usage
- * @ctlr: SPI bus master that was locked for exclusive bus access
- * Context: can sleep
- *
- * This call may only be used from a context that may sleep. The sleep
- * is non-interruptible, and has no timeout.
- *
- * This call releases an SPI bus lock previously obtained by an spi_bus_lock
- * call.
- *
- * Return: always zero.
- */
- int spi_bus_unlock(struct spi_controller *ctlr)
- {
- ctlr->bus_lock_flag = 0;
- mutex_unlock(&ctlr->bus_lock_mutex);
- return 0;
- }
- EXPORT_SYMBOL_GPL(spi_bus_unlock);
- /* portable code must never pass more than 32 bytes */
- #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
- static u8 *buf;
- /**
- * spi_write_then_read - SPI synchronous write followed by read
- * @spi: device with which data will be exchanged
- * @txbuf: data to be written (need not be dma-safe)
- * @n_tx: size of txbuf, in bytes
- * @rxbuf: buffer into which data will be read (need not be dma-safe)
- * @n_rx: size of rxbuf, in bytes
- * Context: can sleep
- *
- * This performs a half duplex MicroWire style transaction with the
- * device, sending txbuf and then reading rxbuf. The return value
- * is zero for success, else a negative errno status code.
- * This call may only be used from a context that may sleep.
- *
- * Parameters to this routine are always copied using a small buffer.
- * Performance-sensitive or bulk transfer code should instead use
- * spi_{async,sync}() calls with dma-safe buffers.
- *
- * Return: zero on success, else a negative error code.
- */
- int spi_write_then_read(struct spi_device *spi,
- const void *txbuf, unsigned n_tx,
- void *rxbuf, unsigned n_rx)
- {
- static DEFINE_MUTEX(lock);
- int status;
- struct spi_message message;
- struct spi_transfer x[2];
- u8 *local_buf;
- /* Use preallocated DMA-safe buffer if we can. We can't avoid
- * copying here, (as a pure convenience thing), but we can
- * keep heap costs out of the hot path unless someone else is
- * using the pre-allocated buffer or the transfer is too large.
- */
- if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
- local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
- GFP_KERNEL | GFP_DMA);
- if (!local_buf)
- return -ENOMEM;
- } else {
- local_buf = buf;
- }
- spi_message_init(&message);
- memset(x, 0, sizeof(x));
- if (n_tx) {
- x[0].len = n_tx;
- spi_message_add_tail(&x[0], &message);
- }
- if (n_rx) {
- x[1].len = n_rx;
- spi_message_add_tail(&x[1], &message);
- }
- memcpy(local_buf, txbuf, n_tx);
- x[0].tx_buf = local_buf;
- x[1].rx_buf = local_buf + n_tx;
- /* do the i/o */
- status = spi_sync(spi, &message);
- if (status == 0)
- memcpy(rxbuf, x[1].rx_buf, n_rx);
- if (x[0].tx_buf == buf)
- mutex_unlock(&lock);
- else
- kfree(local_buf);
- return status;
- }
- EXPORT_SYMBOL_GPL(spi_write_then_read);
- /*-------------------------------------------------------------------------*/
- #if IS_ENABLED(CONFIG_OF)
- /* must call put_device() when done with returned spi_device device */
- struct spi_device *of_find_spi_device_by_node(struct device_node *node)
- {
- struct device *dev = bus_find_device_by_of_node(&spi_bus_type, node);
- return dev ? to_spi_device(dev) : NULL;
- }
- EXPORT_SYMBOL_GPL(of_find_spi_device_by_node);
- #endif /* IS_ENABLED(CONFIG_OF) */
- #if IS_ENABLED(CONFIG_OF_DYNAMIC)
- /* the spi controllers are not using spi_bus, so we find it with another way */
- static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
- {
- struct device *dev;
- dev = class_find_device_by_of_node(&spi_master_class, node);
- if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
- dev = class_find_device_by_of_node(&spi_slave_class, node);
- if (!dev)
- return NULL;
- /* reference got in class_find_device */
- return container_of(dev, struct spi_controller, dev);
- }
- static int of_spi_notify(struct notifier_block *nb, unsigned long action,
- void *arg)
- {
- struct of_reconfig_data *rd = arg;
- struct spi_controller *ctlr;
- struct spi_device *spi;
- switch (of_reconfig_get_state_change(action, arg)) {
- case OF_RECONFIG_CHANGE_ADD:
- ctlr = of_find_spi_controller_by_node(rd->dn->parent);
- if (ctlr == NULL)
- return NOTIFY_OK; /* not for us */
- if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
- put_device(&ctlr->dev);
- return NOTIFY_OK;
- }
- spi = of_register_spi_device(ctlr, rd->dn);
- put_device(&ctlr->dev);
- if (IS_ERR(spi)) {
- pr_err("%s: failed to create for '%pOF'\n",
- __func__, rd->dn);
- of_node_clear_flag(rd->dn, OF_POPULATED);
- return notifier_from_errno(PTR_ERR(spi));
- }
- break;
- case OF_RECONFIG_CHANGE_REMOVE:
- /* already depopulated? */
- if (!of_node_check_flag(rd->dn, OF_POPULATED))
- return NOTIFY_OK;
- /* find our device by node */
- spi = of_find_spi_device_by_node(rd->dn);
- if (spi == NULL)
- return NOTIFY_OK; /* no? not meant for us */
- /* unregister takes one ref away */
- spi_unregister_device(spi);
- /* and put the reference of the find */
- put_device(&spi->dev);
- break;
- }
- return NOTIFY_OK;
- }
- static struct notifier_block spi_of_notifier = {
- .notifier_call = of_spi_notify,
- };
- #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
- extern struct notifier_block spi_of_notifier;
- #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
- #if IS_ENABLED(CONFIG_ACPI)
- static int spi_acpi_controller_match(struct device *dev, const void *data)
- {
- return ACPI_COMPANION(dev->parent) == data;
- }
- static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)
- {
- struct device *dev;
- dev = class_find_device(&spi_master_class, NULL, adev,
- spi_acpi_controller_match);
- if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
- dev = class_find_device(&spi_slave_class, NULL, adev,
- spi_acpi_controller_match);
- if (!dev)
- return NULL;
- return container_of(dev, struct spi_controller, dev);
- }
- static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
- {
- struct device *dev;
- dev = bus_find_device_by_acpi_dev(&spi_bus_type, adev);
- return to_spi_device(dev);
- }
- static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
- void *arg)
- {
- struct acpi_device *adev = arg;
- struct spi_controller *ctlr;
- struct spi_device *spi;
- switch (value) {
- case ACPI_RECONFIG_DEVICE_ADD:
- ctlr = acpi_spi_find_controller_by_adev(adev->parent);
- if (!ctlr)
- break;
- acpi_register_spi_device(ctlr, adev);
- put_device(&ctlr->dev);
- break;
- case ACPI_RECONFIG_DEVICE_REMOVE:
- if (!acpi_device_enumerated(adev))
- break;
- spi = acpi_spi_find_device_by_adev(adev);
- if (!spi)
- break;
- spi_unregister_device(spi);
- put_device(&spi->dev);
- break;
- }
- return NOTIFY_OK;
- }
- static struct notifier_block spi_acpi_notifier = {
- .notifier_call = acpi_spi_notify,
- };
- #else
- extern struct notifier_block spi_acpi_notifier;
- #endif
- static int __init spi_init(void)
- {
- int status;
- buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
- if (!buf) {
- status = -ENOMEM;
- goto err0;
- }
- status = bus_register(&spi_bus_type);
- if (status < 0)
- goto err1;
- status = class_register(&spi_master_class);
- if (status < 0)
- goto err2;
- if (IS_ENABLED(CONFIG_SPI_SLAVE)) {
- status = class_register(&spi_slave_class);
- if (status < 0)
- goto err3;
- }
- if (IS_ENABLED(CONFIG_OF_DYNAMIC))
- WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
- if (IS_ENABLED(CONFIG_ACPI))
- WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
- return 0;
- err3:
- class_unregister(&spi_master_class);
- err2:
- bus_unregister(&spi_bus_type);
- err1:
- kfree(buf);
- buf = NULL;
- err0:
- return status;
- }
- /* board_info is normally registered in arch_initcall(),
- * but even essential drivers wait till later
- *
- * REVISIT only boardinfo really needs static linking. the rest (device and
- * driver registration) _could_ be dynamically linked (modular) ... costs
- * include needing to have boardinfo data structures be much more public.
- */
- postcore_initcall(spi_init);
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