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- // SPDX-License-Identifier: GPL-2.0
- /*
- * Multiplexer subsystem
- *
- * Based on the linux multiplexer framework
- *
- * Copyright (C) 2017 Axentia Technologies AB
- * Author: Peter Rosin <peda@axentia.se>
- *
- * Copyright (C) 2017-2018 Texas Instruments Incorporated - http://www.ti.com/
- * Jean-Jacques Hiblot <jjhiblot@ti.com>
- */
- #define LOG_CATEGORY UCLASS_MUX
- #include <common.h>
- #include <dm.h>
- #include <mux-internal.h>
- #include <dm/device-internal.h>
- #include <dm/device_compat.h>
- #include <dm/devres.h>
- #include <dt-bindings/mux/mux.h>
- #include <linux/bug.h>
- /*
- * The idle-as-is "state" is not an actual state that may be selected, it
- * only implies that the state should not be changed. So, use that state
- * as indication that the cached state of the multiplexer is unknown.
- */
- #define MUX_CACHE_UNKNOWN MUX_IDLE_AS_IS
- /**
- * mux_control_ops() - Get the mux_control ops.
- * @dev: The client device.
- *
- * Return: A pointer to the 'mux_control_ops' of the device.
- */
- static inline const struct mux_control_ops *mux_dev_ops(struct udevice *dev)
- {
- return (const struct mux_control_ops *)dev->driver->ops;
- }
- /**
- * mux_control_set() - Set the state of the given mux controller.
- * @mux: A multiplexer control
- * @state: The new requested state.
- *
- * Return: 0 if OK, or a negative error code.
- */
- static int mux_control_set(struct mux_control *mux, int state)
- {
- int ret = mux_dev_ops(mux->dev)->set(mux, state);
- mux->cached_state = ret < 0 ? MUX_CACHE_UNKNOWN : state;
- return ret;
- }
- unsigned int mux_control_states(struct mux_control *mux)
- {
- return mux->states;
- }
- /**
- * __mux_control_select() - Select the given multiplexer state.
- * @mux: The mux-control to request a change of state from.
- * @state: The new requested state.
- *
- * Try to set the mux to the requested state. If not, try to revert if
- * appropriate.
- */
- static int __mux_control_select(struct mux_control *mux, int state)
- {
- int ret;
- if (WARN_ON(state < 0 || state >= mux->states))
- return -EINVAL;
- if (mux->cached_state == state)
- return 0;
- ret = mux_control_set(mux, state);
- if (ret >= 0)
- return 0;
- /* The mux update failed, try to revert if appropriate... */
- if (mux->idle_state != MUX_IDLE_AS_IS)
- mux_control_set(mux, mux->idle_state);
- return ret;
- }
- int mux_control_select(struct mux_control *mux, unsigned int state)
- {
- int ret;
- if (mux->in_use)
- return -EBUSY;
- ret = __mux_control_select(mux, state);
- if (ret < 0)
- return ret;
- mux->in_use = true;
- return 0;
- }
- int mux_control_deselect(struct mux_control *mux)
- {
- int ret = 0;
- if (mux->idle_state != MUX_IDLE_AS_IS &&
- mux->idle_state != mux->cached_state)
- ret = mux_control_set(mux, mux->idle_state);
- mux->in_use = false;
- return ret;
- }
- static int mux_of_xlate_default(struct mux_chip *mux_chip,
- struct ofnode_phandle_args *args,
- struct mux_control **muxp)
- {
- struct mux_control *mux;
- int id;
- log_debug("%s(muxp=%p)\n", __func__, muxp);
- if (args->args_count > 1) {
- debug("Invaild args_count: %d\n", args->args_count);
- return -EINVAL;
- }
- if (args->args_count)
- id = args->args[0];
- else
- id = 0;
- if (id >= mux_chip->controllers) {
- pr_err("bad mux controller %u specified in %s\n",
- id, ofnode_get_name(args->node));
- return -ERANGE;
- }
- mux = &mux_chip->mux[id];
- mux->id = id;
- *muxp = mux;
- return 0;
- }
- /**
- * mux_get_by_indexed_prop() - Get a mux control by integer index
- * @dev: The client device.
- * @prop_name: Name of the device tree property.
- * @index: The index of the mux to get
- * @mux: A pointer to the 'mux_control' struct to initialize.
- *
- * Return: 0 of OK, -errno otherwise.
- */
- static int mux_get_by_indexed_prop(struct udevice *dev, const char *prop_name,
- int index, struct mux_control **mux)
- {
- int ret;
- struct ofnode_phandle_args args;
- struct udevice *dev_mux;
- const struct mux_control_ops *ops;
- struct mux_chip *mux_chip;
- log_debug("%s(dev=%p, index=%d, mux=%p)\n", __func__, dev, index, mux);
- ret = dev_read_phandle_with_args(dev, prop_name, "#mux-control-cells",
- 0, index, &args);
- if (ret) {
- debug("%s: fdtdec_parse_phandle_with_args failed: err=%d\n",
- __func__, ret);
- return ret;
- }
- ret = uclass_get_device_by_ofnode(UCLASS_MUX, args.node, &dev_mux);
- if (ret) {
- debug("%s: uclass_get_device_by_ofnode failed: err=%d\n",
- __func__, ret);
- return ret;
- }
- mux_chip = dev_get_uclass_priv(dev_mux);
- ops = mux_dev_ops(dev_mux);
- if (ops->of_xlate)
- ret = ops->of_xlate(mux_chip, &args, mux);
- else
- ret = mux_of_xlate_default(mux_chip, &args, mux);
- if (ret) {
- debug("of_xlate() failed: %d\n", ret);
- return ret;
- }
- (*mux)->dev = dev_mux;
- return 0;
- }
- int mux_get_by_index(struct udevice *dev, int index, struct mux_control **mux)
- {
- return mux_get_by_indexed_prop(dev, "mux-controls", index, mux);
- }
- int mux_control_get(struct udevice *dev, const char *name,
- struct mux_control **mux)
- {
- int index;
- debug("%s(dev=%p, name=%s, mux=%p)\n", __func__, dev, name, mux);
- index = dev_read_stringlist_search(dev, "mux-control-names", name);
- if (index < 0) {
- debug("fdt_stringlist_search() failed: %d\n", index);
- return index;
- }
- return mux_get_by_index(dev, index, mux);
- }
- void mux_control_put(struct mux_control *mux)
- {
- mux_control_deselect(mux);
- }
- /**
- * devm_mux_control_release() - Release the given managed mux.
- * @dev: The client device.
- * @res: Pointer to the mux to be released.
- *
- * This function is called by devres to release the mux. It reverses the
- * effects of mux_control_get().
- */
- static void devm_mux_control_release(struct udevice *dev, void *res)
- {
- mux_control_put(*(struct mux_control **)res);
- }
- struct mux_control *devm_mux_control_get(struct udevice *dev, const char *id)
- {
- int rc;
- struct mux_control **mux;
- mux = devres_alloc(devm_mux_control_release,
- sizeof(struct mux_control *), __GFP_ZERO);
- if (unlikely(!mux))
- return ERR_PTR(-ENOMEM);
- rc = mux_control_get(dev, id, mux);
- if (rc)
- return ERR_PTR(rc);
- devres_add(dev, mux);
- return *mux;
- }
- int mux_alloc_controllers(struct udevice *dev, unsigned int controllers)
- {
- int i;
- struct mux_chip *mux_chip = dev_get_uclass_priv(dev);
- mux_chip->mux = devm_kmalloc(dev,
- sizeof(struct mux_control) * controllers,
- __GFP_ZERO);
- if (!mux_chip->mux)
- return -ENOMEM;
- mux_chip->controllers = controllers;
- for (i = 0; i < mux_chip->controllers; ++i) {
- struct mux_control *mux = &mux_chip->mux[i];
- mux->dev = dev;
- mux->cached_state = MUX_CACHE_UNKNOWN;
- mux->idle_state = MUX_IDLE_AS_IS;
- mux->in_use = false;
- mux->id = i;
- }
- return 0;
- }
- static int mux_uclass_post_probe(struct udevice *dev)
- {
- int i, ret;
- struct mux_chip *mux_chip = dev_get_uclass_priv(dev);
- /* Set all mux controllers to their idle state. */
- for (i = 0; i < mux_chip->controllers; ++i) {
- struct mux_control *mux = &mux_chip->mux[i];
- if (mux->idle_state == mux->cached_state)
- continue;
- ret = mux_control_set(mux, mux->idle_state);
- if (ret < 0) {
- dev_err(dev, "unable to set idle state\n");
- return ret;
- }
- }
- return 0;
- }
- int dm_mux_init(void)
- {
- struct uclass *uc;
- struct udevice *dev;
- int ret;
- ret = uclass_get(UCLASS_MUX, &uc);
- if (ret < 0) {
- log_debug("unable to get MUX uclass\n");
- return ret;
- }
- uclass_foreach_dev(dev, uc) {
- if (dev_read_bool(dev, "u-boot,mux-autoprobe")) {
- ret = device_probe(dev);
- if (ret)
- log_debug("unable to probe device %s\n",
- dev->name);
- }
- }
- return 0;
- }
- UCLASS_DRIVER(mux) = {
- .id = UCLASS_MUX,
- .name = "mux",
- .post_probe = mux_uclass_post_probe,
- .per_device_auto = sizeof(struct mux_chip),
- };
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