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- // SPDX-License-Identifier: GPL-2.0
- /*
- * Xilinx AXIS FIFO: interface to the Xilinx AXI-Stream FIFO IP core
- *
- * Copyright (C) 2018 Jacob Feder
- *
- * Authors: Jacob Feder <jacobsfeder@gmail.com>
- *
- * See Xilinx PG080 document for IP details
- */
- /* ----------------------------
- * includes
- * ----------------------------
- */
- #include <linux/kernel.h>
- #include <linux/wait.h>
- #include <linux/mutex.h>
- #include <linux/device.h>
- #include <linux/cdev.h>
- #include <linux/init.h>
- #include <linux/module.h>
- #include <linux/slab.h>
- #include <linux/io.h>
- #include <linux/moduleparam.h>
- #include <linux/interrupt.h>
- #include <linux/param.h>
- #include <linux/fs.h>
- #include <linux/types.h>
- #include <linux/uaccess.h>
- #include <linux/jiffies.h>
- #include <linux/of_address.h>
- #include <linux/of_device.h>
- #include <linux/of_platform.h>
- /* ----------------------------
- * driver parameters
- * ----------------------------
- */
- #define DRIVER_NAME "axis_fifo"
- #define READ_BUF_SIZE 128U /* read buffer length in words */
- #define WRITE_BUF_SIZE 128U /* write buffer length in words */
- /* ----------------------------
- * IP register offsets
- * ----------------------------
- */
- #define XLLF_ISR_OFFSET 0x00000000 /* Interrupt Status */
- #define XLLF_IER_OFFSET 0x00000004 /* Interrupt Enable */
- #define XLLF_TDFR_OFFSET 0x00000008 /* Transmit Reset */
- #define XLLF_TDFV_OFFSET 0x0000000c /* Transmit Vacancy */
- #define XLLF_TDFD_OFFSET 0x00000010 /* Transmit Data */
- #define XLLF_TLR_OFFSET 0x00000014 /* Transmit Length */
- #define XLLF_RDFR_OFFSET 0x00000018 /* Receive Reset */
- #define XLLF_RDFO_OFFSET 0x0000001c /* Receive Occupancy */
- #define XLLF_RDFD_OFFSET 0x00000020 /* Receive Data */
- #define XLLF_RLR_OFFSET 0x00000024 /* Receive Length */
- #define XLLF_SRR_OFFSET 0x00000028 /* Local Link Reset */
- #define XLLF_TDR_OFFSET 0x0000002C /* Transmit Destination */
- #define XLLF_RDR_OFFSET 0x00000030 /* Receive Destination */
- /* ----------------------------
- * reset register masks
- * ----------------------------
- */
- #define XLLF_RDFR_RESET_MASK 0x000000a5 /* receive reset value */
- #define XLLF_TDFR_RESET_MASK 0x000000a5 /* Transmit reset value */
- #define XLLF_SRR_RESET_MASK 0x000000a5 /* Local Link reset value */
- /* ----------------------------
- * interrupt masks
- * ----------------------------
- */
- #define XLLF_INT_RPURE_MASK 0x80000000 /* Receive under-read */
- #define XLLF_INT_RPORE_MASK 0x40000000 /* Receive over-read */
- #define XLLF_INT_RPUE_MASK 0x20000000 /* Receive underrun (empty) */
- #define XLLF_INT_TPOE_MASK 0x10000000 /* Transmit overrun */
- #define XLLF_INT_TC_MASK 0x08000000 /* Transmit complete */
- #define XLLF_INT_RC_MASK 0x04000000 /* Receive complete */
- #define XLLF_INT_TSE_MASK 0x02000000 /* Transmit length mismatch */
- #define XLLF_INT_TRC_MASK 0x01000000 /* Transmit reset complete */
- #define XLLF_INT_RRC_MASK 0x00800000 /* Receive reset complete */
- #define XLLF_INT_TFPF_MASK 0x00400000 /* Tx FIFO Programmable Full */
- #define XLLF_INT_TFPE_MASK 0x00200000 /* Tx FIFO Programmable Empty */
- #define XLLF_INT_RFPF_MASK 0x00100000 /* Rx FIFO Programmable Full */
- #define XLLF_INT_RFPE_MASK 0x00080000 /* Rx FIFO Programmable Empty */
- #define XLLF_INT_ALL_MASK 0xfff80000 /* All the ints */
- #define XLLF_INT_ERROR_MASK 0xf2000000 /* Error status ints */
- #define XLLF_INT_RXERROR_MASK 0xe0000000 /* Receive Error status ints */
- #define XLLF_INT_TXERROR_MASK 0x12000000 /* Transmit Error status ints */
- /* ----------------------------
- * globals
- * ----------------------------
- */
- static struct class *axis_fifo_driver_class; /* char device class */
- static int read_timeout = 1000; /* ms to wait before read() times out */
- static int write_timeout = 1000; /* ms to wait before write() times out */
- /* ----------------------------
- * module command-line arguments
- * ----------------------------
- */
- module_param(read_timeout, int, 0444);
- MODULE_PARM_DESC(read_timeout, "ms to wait before blocking read() timing out; set to -1 for no timeout");
- module_param(write_timeout, int, 0444);
- MODULE_PARM_DESC(write_timeout, "ms to wait before blocking write() timing out; set to -1 for no timeout");
- /* ----------------------------
- * types
- * ----------------------------
- */
- struct axis_fifo {
- int irq; /* interrupt */
- void __iomem *base_addr; /* kernel space memory */
- unsigned int rx_fifo_depth; /* max words in the receive fifo */
- unsigned int tx_fifo_depth; /* max words in the transmit fifo */
- int has_rx_fifo; /* whether the IP has the rx fifo enabled */
- int has_tx_fifo; /* whether the IP has the tx fifo enabled */
- wait_queue_head_t read_queue; /* wait queue for asynchronos read */
- struct mutex read_lock; /* lock for reading */
- wait_queue_head_t write_queue; /* wait queue for asynchronos write */
- struct mutex write_lock; /* lock for writing */
- unsigned int write_flags; /* write file flags */
- unsigned int read_flags; /* read file flags */
- struct device *dt_device; /* device created from the device tree */
- struct device *device; /* device associated with char_device */
- dev_t devt; /* our char device number */
- struct cdev char_device; /* our char device */
- };
- /* ----------------------------
- * sysfs entries
- * ----------------------------
- */
- static ssize_t sysfs_write(struct device *dev, const char *buf,
- size_t count, unsigned int addr_offset)
- {
- struct axis_fifo *fifo = dev_get_drvdata(dev);
- unsigned long tmp;
- int rc;
- rc = kstrtoul(buf, 0, &tmp);
- if (rc < 0)
- return rc;
- iowrite32(tmp, fifo->base_addr + addr_offset);
- return count;
- }
- static ssize_t sysfs_read(struct device *dev, char *buf,
- unsigned int addr_offset)
- {
- struct axis_fifo *fifo = dev_get_drvdata(dev);
- unsigned int read_val;
- unsigned int len;
- char tmp[32];
- read_val = ioread32(fifo->base_addr + addr_offset);
- len = snprintf(tmp, sizeof(tmp), "0x%x\n", read_val);
- memcpy(buf, tmp, len);
- return len;
- }
- static ssize_t isr_store(struct device *dev, struct device_attribute *attr,
- const char *buf, size_t count)
- {
- return sysfs_write(dev, buf, count, XLLF_ISR_OFFSET);
- }
- static ssize_t isr_show(struct device *dev,
- struct device_attribute *attr, char *buf)
- {
- return sysfs_read(dev, buf, XLLF_ISR_OFFSET);
- }
- static DEVICE_ATTR_RW(isr);
- static ssize_t ier_store(struct device *dev, struct device_attribute *attr,
- const char *buf, size_t count)
- {
- return sysfs_write(dev, buf, count, XLLF_IER_OFFSET);
- }
- static ssize_t ier_show(struct device *dev,
- struct device_attribute *attr, char *buf)
- {
- return sysfs_read(dev, buf, XLLF_IER_OFFSET);
- }
- static DEVICE_ATTR_RW(ier);
- static ssize_t tdfr_store(struct device *dev, struct device_attribute *attr,
- const char *buf, size_t count)
- {
- return sysfs_write(dev, buf, count, XLLF_TDFR_OFFSET);
- }
- static DEVICE_ATTR_WO(tdfr);
- static ssize_t tdfv_show(struct device *dev,
- struct device_attribute *attr, char *buf)
- {
- return sysfs_read(dev, buf, XLLF_TDFV_OFFSET);
- }
- static DEVICE_ATTR_RO(tdfv);
- static ssize_t tdfd_store(struct device *dev, struct device_attribute *attr,
- const char *buf, size_t count)
- {
- return sysfs_write(dev, buf, count, XLLF_TDFD_OFFSET);
- }
- static DEVICE_ATTR_WO(tdfd);
- static ssize_t tlr_store(struct device *dev, struct device_attribute *attr,
- const char *buf, size_t count)
- {
- return sysfs_write(dev, buf, count, XLLF_TLR_OFFSET);
- }
- static DEVICE_ATTR_WO(tlr);
- static ssize_t rdfr_store(struct device *dev, struct device_attribute *attr,
- const char *buf, size_t count)
- {
- return sysfs_write(dev, buf, count, XLLF_RDFR_OFFSET);
- }
- static DEVICE_ATTR_WO(rdfr);
- static ssize_t rdfo_show(struct device *dev,
- struct device_attribute *attr, char *buf)
- {
- return sysfs_read(dev, buf, XLLF_RDFO_OFFSET);
- }
- static DEVICE_ATTR_RO(rdfo);
- static ssize_t rdfd_show(struct device *dev,
- struct device_attribute *attr, char *buf)
- {
- return sysfs_read(dev, buf, XLLF_RDFD_OFFSET);
- }
- static DEVICE_ATTR_RO(rdfd);
- static ssize_t rlr_show(struct device *dev,
- struct device_attribute *attr, char *buf)
- {
- return sysfs_read(dev, buf, XLLF_RLR_OFFSET);
- }
- static DEVICE_ATTR_RO(rlr);
- static ssize_t srr_store(struct device *dev, struct device_attribute *attr,
- const char *buf, size_t count)
- {
- return sysfs_write(dev, buf, count, XLLF_SRR_OFFSET);
- }
- static DEVICE_ATTR_WO(srr);
- static ssize_t tdr_store(struct device *dev, struct device_attribute *attr,
- const char *buf, size_t count)
- {
- return sysfs_write(dev, buf, count, XLLF_TDR_OFFSET);
- }
- static DEVICE_ATTR_WO(tdr);
- static ssize_t rdr_show(struct device *dev,
- struct device_attribute *attr, char *buf)
- {
- return sysfs_read(dev, buf, XLLF_RDR_OFFSET);
- }
- static DEVICE_ATTR_RO(rdr);
- static struct attribute *axis_fifo_attrs[] = {
- &dev_attr_isr.attr,
- &dev_attr_ier.attr,
- &dev_attr_tdfr.attr,
- &dev_attr_tdfv.attr,
- &dev_attr_tdfd.attr,
- &dev_attr_tlr.attr,
- &dev_attr_rdfr.attr,
- &dev_attr_rdfo.attr,
- &dev_attr_rdfd.attr,
- &dev_attr_rlr.attr,
- &dev_attr_srr.attr,
- &dev_attr_tdr.attr,
- &dev_attr_rdr.attr,
- NULL,
- };
- static const struct attribute_group axis_fifo_attrs_group = {
- .name = "ip_registers",
- .attrs = axis_fifo_attrs,
- };
- /* ----------------------------
- * implementation
- * ----------------------------
- */
- static void reset_ip_core(struct axis_fifo *fifo)
- {
- iowrite32(XLLF_SRR_RESET_MASK, fifo->base_addr + XLLF_SRR_OFFSET);
- iowrite32(XLLF_TDFR_RESET_MASK, fifo->base_addr + XLLF_TDFR_OFFSET);
- iowrite32(XLLF_RDFR_RESET_MASK, fifo->base_addr + XLLF_RDFR_OFFSET);
- iowrite32(XLLF_INT_TC_MASK | XLLF_INT_RC_MASK | XLLF_INT_RPURE_MASK |
- XLLF_INT_RPORE_MASK | XLLF_INT_RPUE_MASK |
- XLLF_INT_TPOE_MASK | XLLF_INT_TSE_MASK,
- fifo->base_addr + XLLF_IER_OFFSET);
- iowrite32(XLLF_INT_ALL_MASK, fifo->base_addr + XLLF_ISR_OFFSET);
- }
- /**
- * axis_fifo_write() - Read a packet from AXIS-FIFO character device.
- * @f Open file.
- * @buf User space buffer to read to.
- * @len User space buffer length.
- * @off Buffer offset.
- *
- * As defined by the device's documentation, we need to check the device's
- * occupancy before reading the length register and then the data. All these
- * operations must be executed atomically, in order and one after the other
- * without missing any.
- *
- * Returns the number of bytes read from the device or negative error code
- * on failure.
- */
- static ssize_t axis_fifo_read(struct file *f, char __user *buf,
- size_t len, loff_t *off)
- {
- struct axis_fifo *fifo = (struct axis_fifo *)f->private_data;
- size_t bytes_available;
- unsigned int words_available;
- unsigned int copied;
- unsigned int copy;
- unsigned int i;
- int ret;
- u32 tmp_buf[READ_BUF_SIZE];
- if (fifo->read_flags & O_NONBLOCK) {
- /*
- * Device opened in non-blocking mode. Try to lock it and then
- * check if any packet is available.
- */
- if (!mutex_trylock(&fifo->read_lock))
- return -EAGAIN;
- if (!ioread32(fifo->base_addr + XLLF_RDFO_OFFSET)) {
- ret = -EAGAIN;
- goto end_unlock;
- }
- } else {
- /* opened in blocking mode
- * wait for a packet available interrupt (or timeout)
- * if nothing is currently available
- */
- mutex_lock(&fifo->read_lock);
- ret = wait_event_interruptible_timeout(fifo->read_queue,
- ioread32(fifo->base_addr + XLLF_RDFO_OFFSET),
- (read_timeout >= 0) ?
- msecs_to_jiffies(read_timeout) :
- MAX_SCHEDULE_TIMEOUT);
- if (ret <= 0) {
- if (ret == 0) {
- ret = -EAGAIN;
- } else if (ret != -ERESTARTSYS) {
- dev_err(fifo->dt_device, "wait_event_interruptible_timeout() error in read (ret=%i)\n",
- ret);
- }
- goto end_unlock;
- }
- }
- bytes_available = ioread32(fifo->base_addr + XLLF_RLR_OFFSET);
- if (!bytes_available) {
- dev_err(fifo->dt_device, "received a packet of length 0 - fifo core will be reset\n");
- reset_ip_core(fifo);
- ret = -EIO;
- goto end_unlock;
- }
- if (bytes_available > len) {
- dev_err(fifo->dt_device, "user read buffer too small (available bytes=%zu user buffer bytes=%zu) - fifo core will be reset\n",
- bytes_available, len);
- reset_ip_core(fifo);
- ret = -EINVAL;
- goto end_unlock;
- }
- if (bytes_available % sizeof(u32)) {
- /* this probably can't happen unless IP
- * registers were previously mishandled
- */
- dev_err(fifo->dt_device, "received a packet that isn't word-aligned - fifo core will be reset\n");
- reset_ip_core(fifo);
- ret = -EIO;
- goto end_unlock;
- }
- words_available = bytes_available / sizeof(u32);
- /* read data into an intermediate buffer, copying the contents
- * to userspace when the buffer is full
- */
- copied = 0;
- while (words_available > 0) {
- copy = min(words_available, READ_BUF_SIZE);
- for (i = 0; i < copy; i++) {
- tmp_buf[i] = ioread32(fifo->base_addr +
- XLLF_RDFD_OFFSET);
- }
- if (copy_to_user(buf + copied * sizeof(u32), tmp_buf,
- copy * sizeof(u32))) {
- reset_ip_core(fifo);
- ret = -EFAULT;
- goto end_unlock;
- }
- copied += copy;
- words_available -= copy;
- }
- ret = bytes_available;
- end_unlock:
- mutex_unlock(&fifo->read_lock);
- return ret;
- }
- /**
- * axis_fifo_write() - Write buffer to AXIS-FIFO character device.
- * @f Open file.
- * @buf User space buffer to write to the device.
- * @len User space buffer length.
- * @off Buffer offset.
- *
- * As defined by the device's documentation, we need to write to the device's
- * data buffer then to the device's packet length register atomically. Also,
- * we need to lock before checking if the device has available space to avoid
- * any concurrency issue.
- *
- * Returns the number of bytes written to the device or negative error code
- * on failure.
- */
- static ssize_t axis_fifo_write(struct file *f, const char __user *buf,
- size_t len, loff_t *off)
- {
- struct axis_fifo *fifo = (struct axis_fifo *)f->private_data;
- unsigned int words_to_write;
- unsigned int copied;
- unsigned int copy;
- unsigned int i;
- int ret;
- u32 tmp_buf[WRITE_BUF_SIZE];
- if (len % sizeof(u32)) {
- dev_err(fifo->dt_device,
- "tried to send a packet that isn't word-aligned\n");
- return -EINVAL;
- }
- words_to_write = len / sizeof(u32);
- if (!words_to_write) {
- dev_err(fifo->dt_device,
- "tried to send a packet of length 0\n");
- return -EINVAL;
- }
- if (words_to_write > fifo->tx_fifo_depth) {
- dev_err(fifo->dt_device, "tried to write more words [%u] than slots in the fifo buffer [%u]\n",
- words_to_write, fifo->tx_fifo_depth);
- return -EINVAL;
- }
- if (fifo->write_flags & O_NONBLOCK) {
- /*
- * Device opened in non-blocking mode. Try to lock it and then
- * check if there is any room to write the given buffer.
- */
- if (!mutex_trylock(&fifo->write_lock))
- return -EAGAIN;
- if (words_to_write > ioread32(fifo->base_addr +
- XLLF_TDFV_OFFSET)) {
- ret = -EAGAIN;
- goto end_unlock;
- }
- } else {
- /* opened in blocking mode */
- /* wait for an interrupt (or timeout) if there isn't
- * currently enough room in the fifo
- */
- mutex_lock(&fifo->write_lock);
- ret = wait_event_interruptible_timeout(fifo->write_queue,
- ioread32(fifo->base_addr + XLLF_TDFV_OFFSET)
- >= words_to_write,
- (write_timeout >= 0) ?
- msecs_to_jiffies(write_timeout) :
- MAX_SCHEDULE_TIMEOUT);
- if (ret <= 0) {
- if (ret == 0) {
- ret = -EAGAIN;
- } else if (ret != -ERESTARTSYS) {
- dev_err(fifo->dt_device, "wait_event_interruptible_timeout() error in write (ret=%i)\n",
- ret);
- }
- goto end_unlock;
- }
- }
- /* write data from an intermediate buffer into the fifo IP, refilling
- * the buffer with userspace data as needed
- */
- copied = 0;
- while (words_to_write > 0) {
- copy = min(words_to_write, WRITE_BUF_SIZE);
- if (copy_from_user(tmp_buf, buf + copied * sizeof(u32),
- copy * sizeof(u32))) {
- reset_ip_core(fifo);
- ret = -EFAULT;
- goto end_unlock;
- }
- for (i = 0; i < copy; i++)
- iowrite32(tmp_buf[i], fifo->base_addr +
- XLLF_TDFD_OFFSET);
- copied += copy;
- words_to_write -= copy;
- }
- ret = copied * sizeof(u32);
- /* write packet size to fifo */
- iowrite32(ret, fifo->base_addr + XLLF_TLR_OFFSET);
- end_unlock:
- mutex_unlock(&fifo->write_lock);
- return ret;
- }
- static irqreturn_t axis_fifo_irq(int irq, void *dw)
- {
- struct axis_fifo *fifo = (struct axis_fifo *)dw;
- unsigned int pending_interrupts;
- do {
- pending_interrupts = ioread32(fifo->base_addr +
- XLLF_IER_OFFSET) &
- ioread32(fifo->base_addr
- + XLLF_ISR_OFFSET);
- if (pending_interrupts & XLLF_INT_RC_MASK) {
- /* packet received */
- /* wake the reader process if it is waiting */
- wake_up(&fifo->read_queue);
- /* clear interrupt */
- iowrite32(XLLF_INT_RC_MASK & XLLF_INT_ALL_MASK,
- fifo->base_addr + XLLF_ISR_OFFSET);
- } else if (pending_interrupts & XLLF_INT_TC_MASK) {
- /* packet sent */
- /* wake the writer process if it is waiting */
- wake_up(&fifo->write_queue);
- iowrite32(XLLF_INT_TC_MASK & XLLF_INT_ALL_MASK,
- fifo->base_addr + XLLF_ISR_OFFSET);
- } else if (pending_interrupts & XLLF_INT_TFPF_MASK) {
- /* transmit fifo programmable full */
- iowrite32(XLLF_INT_TFPF_MASK & XLLF_INT_ALL_MASK,
- fifo->base_addr + XLLF_ISR_OFFSET);
- } else if (pending_interrupts & XLLF_INT_TFPE_MASK) {
- /* transmit fifo programmable empty */
- iowrite32(XLLF_INT_TFPE_MASK & XLLF_INT_ALL_MASK,
- fifo->base_addr + XLLF_ISR_OFFSET);
- } else if (pending_interrupts & XLLF_INT_RFPF_MASK) {
- /* receive fifo programmable full */
- iowrite32(XLLF_INT_RFPF_MASK & XLLF_INT_ALL_MASK,
- fifo->base_addr + XLLF_ISR_OFFSET);
- } else if (pending_interrupts & XLLF_INT_RFPE_MASK) {
- /* receive fifo programmable empty */
- iowrite32(XLLF_INT_RFPE_MASK & XLLF_INT_ALL_MASK,
- fifo->base_addr + XLLF_ISR_OFFSET);
- } else if (pending_interrupts & XLLF_INT_TRC_MASK) {
- /* transmit reset complete interrupt */
- iowrite32(XLLF_INT_TRC_MASK & XLLF_INT_ALL_MASK,
- fifo->base_addr + XLLF_ISR_OFFSET);
- } else if (pending_interrupts & XLLF_INT_RRC_MASK) {
- /* receive reset complete interrupt */
- iowrite32(XLLF_INT_RRC_MASK & XLLF_INT_ALL_MASK,
- fifo->base_addr + XLLF_ISR_OFFSET);
- } else if (pending_interrupts & XLLF_INT_RPURE_MASK) {
- /* receive fifo under-read error interrupt */
- dev_err(fifo->dt_device,
- "receive under-read interrupt\n");
- iowrite32(XLLF_INT_RPURE_MASK & XLLF_INT_ALL_MASK,
- fifo->base_addr + XLLF_ISR_OFFSET);
- } else if (pending_interrupts & XLLF_INT_RPORE_MASK) {
- /* receive over-read error interrupt */
- dev_err(fifo->dt_device,
- "receive over-read interrupt\n");
- iowrite32(XLLF_INT_RPORE_MASK & XLLF_INT_ALL_MASK,
- fifo->base_addr + XLLF_ISR_OFFSET);
- } else if (pending_interrupts & XLLF_INT_RPUE_MASK) {
- /* receive underrun error interrupt */
- dev_err(fifo->dt_device,
- "receive underrun error interrupt\n");
- iowrite32(XLLF_INT_RPUE_MASK & XLLF_INT_ALL_MASK,
- fifo->base_addr + XLLF_ISR_OFFSET);
- } else if (pending_interrupts & XLLF_INT_TPOE_MASK) {
- /* transmit overrun error interrupt */
- dev_err(fifo->dt_device,
- "transmit overrun error interrupt\n");
- iowrite32(XLLF_INT_TPOE_MASK & XLLF_INT_ALL_MASK,
- fifo->base_addr + XLLF_ISR_OFFSET);
- } else if (pending_interrupts & XLLF_INT_TSE_MASK) {
- /* transmit length mismatch error interrupt */
- dev_err(fifo->dt_device,
- "transmit length mismatch error interrupt\n");
- iowrite32(XLLF_INT_TSE_MASK & XLLF_INT_ALL_MASK,
- fifo->base_addr + XLLF_ISR_OFFSET);
- } else if (pending_interrupts) {
- /* unknown interrupt type */
- dev_err(fifo->dt_device,
- "unknown interrupt(s) 0x%x\n",
- pending_interrupts);
- iowrite32(XLLF_INT_ALL_MASK,
- fifo->base_addr + XLLF_ISR_OFFSET);
- }
- } while (pending_interrupts);
- return IRQ_HANDLED;
- }
- static int axis_fifo_open(struct inode *inod, struct file *f)
- {
- struct axis_fifo *fifo = (struct axis_fifo *)container_of(inod->i_cdev,
- struct axis_fifo, char_device);
- f->private_data = fifo;
- if (((f->f_flags & O_ACCMODE) == O_WRONLY) ||
- ((f->f_flags & O_ACCMODE) == O_RDWR)) {
- if (fifo->has_tx_fifo) {
- fifo->write_flags = f->f_flags;
- } else {
- dev_err(fifo->dt_device, "tried to open device for write but the transmit fifo is disabled\n");
- return -EPERM;
- }
- }
- if (((f->f_flags & O_ACCMODE) == O_RDONLY) ||
- ((f->f_flags & O_ACCMODE) == O_RDWR)) {
- if (fifo->has_rx_fifo) {
- fifo->read_flags = f->f_flags;
- } else {
- dev_err(fifo->dt_device, "tried to open device for read but the receive fifo is disabled\n");
- return -EPERM;
- }
- }
- return 0;
- }
- static int axis_fifo_close(struct inode *inod, struct file *f)
- {
- f->private_data = NULL;
- return 0;
- }
- static const struct file_operations fops = {
- .owner = THIS_MODULE,
- .open = axis_fifo_open,
- .release = axis_fifo_close,
- .read = axis_fifo_read,
- .write = axis_fifo_write
- };
- /* read named property from the device tree */
- static int get_dts_property(struct axis_fifo *fifo,
- char *name, unsigned int *var)
- {
- int rc;
- rc = of_property_read_u32(fifo->dt_device->of_node, name, var);
- if (rc) {
- dev_err(fifo->dt_device, "couldn't read IP dts property '%s'",
- name);
- return rc;
- }
- dev_dbg(fifo->dt_device, "dts property '%s' = %u\n",
- name, *var);
- return 0;
- }
- static int axis_fifo_parse_dt(struct axis_fifo *fifo)
- {
- int ret;
- unsigned int value;
- ret = get_dts_property(fifo, "xlnx,axi-str-rxd-tdata-width", &value);
- if (ret) {
- dev_err(fifo->dt_device, "missing xlnx,axi-str-rxd-tdata-width property\n");
- goto end;
- } else if (value != 32) {
- dev_err(fifo->dt_device, "xlnx,axi-str-rxd-tdata-width only supports 32 bits\n");
- ret = -EIO;
- goto end;
- }
- ret = get_dts_property(fifo, "xlnx,axi-str-txd-tdata-width", &value);
- if (ret) {
- dev_err(fifo->dt_device, "missing xlnx,axi-str-txd-tdata-width property\n");
- goto end;
- } else if (value != 32) {
- dev_err(fifo->dt_device, "xlnx,axi-str-txd-tdata-width only supports 32 bits\n");
- ret = -EIO;
- goto end;
- }
- ret = get_dts_property(fifo, "xlnx,rx-fifo-depth",
- &fifo->rx_fifo_depth);
- if (ret) {
- dev_err(fifo->dt_device, "missing xlnx,rx-fifo-depth property\n");
- ret = -EIO;
- goto end;
- }
- ret = get_dts_property(fifo, "xlnx,tx-fifo-depth",
- &fifo->tx_fifo_depth);
- if (ret) {
- dev_err(fifo->dt_device, "missing xlnx,tx-fifo-depth property\n");
- ret = -EIO;
- goto end;
- }
- /* IP sets TDFV to fifo depth - 4 so we will do the same */
- fifo->tx_fifo_depth -= 4;
- ret = get_dts_property(fifo, "xlnx,use-rx-data", &fifo->has_rx_fifo);
- if (ret) {
- dev_err(fifo->dt_device, "missing xlnx,use-rx-data property\n");
- ret = -EIO;
- goto end;
- }
- ret = get_dts_property(fifo, "xlnx,use-tx-data", &fifo->has_tx_fifo);
- if (ret) {
- dev_err(fifo->dt_device, "missing xlnx,use-tx-data property\n");
- ret = -EIO;
- goto end;
- }
- end:
- return ret;
- }
- static int axis_fifo_probe(struct platform_device *pdev)
- {
- struct resource *r_irq; /* interrupt resources */
- struct resource *r_mem; /* IO mem resources */
- struct device *dev = &pdev->dev; /* OS device (from device tree) */
- struct axis_fifo *fifo = NULL;
- char device_name[32];
- int rc = 0; /* error return value */
- /* ----------------------------
- * init wrapper device
- * ----------------------------
- */
- /* allocate device wrapper memory */
- fifo = devm_kmalloc(dev, sizeof(*fifo), GFP_KERNEL);
- if (!fifo)
- return -ENOMEM;
- dev_set_drvdata(dev, fifo);
- fifo->dt_device = dev;
- init_waitqueue_head(&fifo->read_queue);
- init_waitqueue_head(&fifo->write_queue);
- mutex_init(&fifo->read_lock);
- mutex_init(&fifo->write_lock);
- /* ----------------------------
- * init device memory space
- * ----------------------------
- */
- /* get iospace for the device */
- r_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!r_mem) {
- dev_err(fifo->dt_device, "invalid address\n");
- rc = -ENODEV;
- goto err_initial;
- }
- /* request physical memory */
- fifo->base_addr = devm_ioremap_resource(fifo->dt_device, r_mem);
- if (IS_ERR(fifo->base_addr)) {
- rc = PTR_ERR(fifo->base_addr);
- dev_err(fifo->dt_device, "can't remap IO resource (%d)\n", rc);
- goto err_initial;
- }
- dev_dbg(fifo->dt_device, "remapped memory to 0x%p\n", fifo->base_addr);
- /* create unique device name */
- snprintf(device_name, sizeof(device_name), "%s_%pa",
- DRIVER_NAME, &r_mem->start);
- dev_dbg(fifo->dt_device, "device name [%s]\n", device_name);
- /* ----------------------------
- * init IP
- * ----------------------------
- */
- rc = axis_fifo_parse_dt(fifo);
- if (rc)
- goto err_initial;
- reset_ip_core(fifo);
- /* ----------------------------
- * init device interrupts
- * ----------------------------
- */
- /* get IRQ resource */
- r_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
- if (!r_irq) {
- dev_err(fifo->dt_device, "no IRQ found for 0x%pa\n",
- &r_mem->start);
- rc = -EIO;
- goto err_initial;
- }
- /* request IRQ */
- fifo->irq = r_irq->start;
- rc = devm_request_irq(fifo->dt_device, fifo->irq, &axis_fifo_irq, 0,
- DRIVER_NAME, fifo);
- if (rc) {
- dev_err(fifo->dt_device, "couldn't allocate interrupt %i\n",
- fifo->irq);
- goto err_initial;
- }
- /* ----------------------------
- * init char device
- * ----------------------------
- */
- /* allocate device number */
- rc = alloc_chrdev_region(&fifo->devt, 0, 1, DRIVER_NAME);
- if (rc < 0)
- goto err_initial;
- dev_dbg(fifo->dt_device, "allocated device number major %i minor %i\n",
- MAJOR(fifo->devt), MINOR(fifo->devt));
- /* create driver file */
- fifo->device = device_create(axis_fifo_driver_class, NULL, fifo->devt,
- NULL, device_name);
- if (IS_ERR(fifo->device)) {
- dev_err(fifo->dt_device,
- "couldn't create driver file\n");
- rc = PTR_ERR(fifo->device);
- goto err_chrdev_region;
- }
- dev_set_drvdata(fifo->device, fifo);
- /* create character device */
- cdev_init(&fifo->char_device, &fops);
- rc = cdev_add(&fifo->char_device, fifo->devt, 1);
- if (rc < 0) {
- dev_err(fifo->dt_device, "couldn't create character device\n");
- goto err_dev;
- }
- /* create sysfs entries */
- rc = devm_device_add_group(fifo->device, &axis_fifo_attrs_group);
- if (rc < 0) {
- dev_err(fifo->dt_device, "couldn't register sysfs group\n");
- goto err_cdev;
- }
- dev_info(fifo->dt_device, "axis-fifo created at %pa mapped to 0x%pa, irq=%i, major=%i, minor=%i\n",
- &r_mem->start, &fifo->base_addr, fifo->irq,
- MAJOR(fifo->devt), MINOR(fifo->devt));
- return 0;
- err_cdev:
- cdev_del(&fifo->char_device);
- err_dev:
- device_destroy(axis_fifo_driver_class, fifo->devt);
- err_chrdev_region:
- unregister_chrdev_region(fifo->devt, 1);
- err_initial:
- dev_set_drvdata(dev, NULL);
- return rc;
- }
- static int axis_fifo_remove(struct platform_device *pdev)
- {
- struct device *dev = &pdev->dev;
- struct axis_fifo *fifo = dev_get_drvdata(dev);
- cdev_del(&fifo->char_device);
- dev_set_drvdata(fifo->device, NULL);
- device_destroy(axis_fifo_driver_class, fifo->devt);
- unregister_chrdev_region(fifo->devt, 1);
- dev_set_drvdata(dev, NULL);
- return 0;
- }
- static const struct of_device_id axis_fifo_of_match[] = {
- { .compatible = "xlnx,axi-fifo-mm-s-4.1", },
- {},
- };
- MODULE_DEVICE_TABLE(of, axis_fifo_of_match);
- static struct platform_driver axis_fifo_driver = {
- .driver = {
- .name = DRIVER_NAME,
- .of_match_table = axis_fifo_of_match,
- },
- .probe = axis_fifo_probe,
- .remove = axis_fifo_remove,
- };
- static int __init axis_fifo_init(void)
- {
- pr_info("axis-fifo driver loaded with parameters read_timeout = %i, write_timeout = %i\n",
- read_timeout, write_timeout);
- axis_fifo_driver_class = class_create(THIS_MODULE, DRIVER_NAME);
- if (IS_ERR(axis_fifo_driver_class))
- return PTR_ERR(axis_fifo_driver_class);
- return platform_driver_register(&axis_fifo_driver);
- }
- module_init(axis_fifo_init);
- static void __exit axis_fifo_exit(void)
- {
- platform_driver_unregister(&axis_fifo_driver);
- class_destroy(axis_fifo_driver_class);
- }
- module_exit(axis_fifo_exit);
- MODULE_LICENSE("GPL");
- MODULE_AUTHOR("Jacob Feder <jacobsfeder@gmail.com>");
- MODULE_DESCRIPTION("Xilinx AXI-Stream FIFO v4.1 IP core driver");
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