drivers/mux/mux-uclass.c - github/trini/u-boot - Gitiles

 // 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 - https://www.ti.com/
  * Jean-Jacques Hiblot <jjhiblot@ti.com>
  */

 #define LOG_CATEGORY UCLASS_MUX

 #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("Invalid 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") ||
 		    dev_read_bool(dev, "idle-states")) {
 			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),
 };
	// 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 - https://www.ti.com/
	* Jean-Jacques Hiblot <jjhiblot@ti.com>
	*/

	#define LOG_CATEGORY UCLASS_MUX

	#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("Invalid 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") \|\|
	dev_read_bool(dev, "idle-states")) {
	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),
	};