drivers/clk/clkdev.c - kernel/msm-4.9 - Gitiles

 /*
  * drivers/clk/clkdev.c
  *
  *  Copyright (C) 2008 Russell King.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
  * Helper for the clk API to assist looking up a struct clk.
  */
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/device.h>
 #include <linux/list.h>
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/string.h>
 #include <linux/mutex.h>
 #include <linux/clk.h>
 #include <linux/clkdev.h>
 #include <linux/of.h>

 static LIST_HEAD(clocks);
 static DEFINE_MUTEX(clocks_mutex);

 #if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
 struct clk *of_clk_get(struct device_node *np, int index)
 {
 	struct of_phandle_args clkspec;
 	struct clk *clk;
 	int rc;

 	if (index < 0)
 		return ERR_PTR(-EINVAL);

 	rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
 					&clkspec);
 	if (rc)
 		return ERR_PTR(rc);

 	clk = of_clk_get_from_provider(&clkspec);
 	of_node_put(clkspec.np);
 	return clk;
 }
 EXPORT_SYMBOL(of_clk_get);

 /**
  * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
  * @np: pointer to clock consumer node
  * @name: name of consumer's clock input, or NULL for the first clock reference
  *
  * This function parses the clocks and clock-names properties,
  * and uses them to look up the struct clk from the registered list of clock
  * providers.
  */
 struct clk *of_clk_get_by_name(struct device_node *np, const char *name)
 {
 	struct clk *clk = ERR_PTR(-ENOENT);

 	/* Walk up the tree of devices looking for a clock that matches */
 	while (np) {
 		int index = 0;

 		/*
 		 * For named clocks, first look up the name in the
 		 * "clock-names" property.  If it cannot be found, then
 		 * index will be an error code, and of_clk_get() will fail.
 		 */
 		if (name)
 			index = of_property_match_string(np, "clock-names", name);
 		clk = of_clk_get(np, index);
 		if (!IS_ERR(clk))
 			break;
 		else if (name && index >= 0) {
 			pr_err("ERROR: could not get clock %s:%s(%i)\n",
 				np->full_name, name ? name : "", index);
 			return clk;
 		}

 		/*
 		 * No matching clock found on this node.  If the parent node
 		 * has a "clock-ranges" property, then we can try one of its
 		 * clocks.
 		 */
 		np = np->parent;
 		if (np && !of_get_property(np, "clock-ranges", NULL))
 			break;
 	}

 	return clk;
 }
 EXPORT_SYMBOL(of_clk_get_by_name);
 #endif

 /*
  * Find the correct struct clk for the device and connection ID.
  * We do slightly fuzzy matching here:
  *  An entry with a NULL ID is assumed to be a wildcard.
  *  If an entry has a device ID, it must match
  *  If an entry has a connection ID, it must match
  * Then we take the most specific entry - with the following
  * order of precedence: dev+con > dev only > con only.
  */
 static struct clk_lookup *clk_find(const char *dev_id, const char *con_id)
 {
 	struct clk_lookup *p, *cl = NULL;
 	int match, best_found = 0, best_possible = 0;

 	if (dev_id)
 		best_possible += 2;
 	if (con_id)
 		best_possible += 1;

 	list_for_each_entry(p, &clocks, node) {
 		match = 0;
 		if (p->dev_id) {
 			if (!dev_id || strcmp(p->dev_id, dev_id))
 				continue;
 			match += 2;
 		}
 		if (p->con_id) {
 			if (!con_id || strcmp(p->con_id, con_id))
 				continue;
 			match += 1;
 		}

 		if (match > best_found) {
 			cl = p;
 			if (match != best_possible)
 				best_found = match;
 			else
 				break;
 		}
 	}
 	return cl;
 }

 struct clk *clk_get_sys(const char *dev_id, const char *con_id)
 {
 	struct clk_lookup *cl;

 	mutex_lock(&clocks_mutex);
 	cl = clk_find(dev_id, con_id);
 	if (cl && !__clk_get(cl->clk))
 		cl = NULL;
 	mutex_unlock(&clocks_mutex);

 	return cl ? cl->clk : ERR_PTR(-ENOENT);
 }
 EXPORT_SYMBOL(clk_get_sys);

 struct clk *clk_get(struct device *dev, const char *con_id)
 {
 	const char *dev_id = dev ? dev_name(dev) : NULL;
 	struct clk *clk;

 	if (dev) {
 		clk = of_clk_get_by_name(dev->of_node, con_id);
 		if (!IS_ERR(clk) && __clk_get(clk))
 			return clk;
 	}

 	return clk_get_sys(dev_id, con_id);
 }
 EXPORT_SYMBOL(clk_get);

 void clk_put(struct clk *clk)
 {
 	__clk_put(clk);
 }
 EXPORT_SYMBOL(clk_put);

 void clkdev_add(struct clk_lookup *cl)
 {
 	mutex_lock(&clocks_mutex);
 	list_add_tail(&cl->node, &clocks);
 	mutex_unlock(&clocks_mutex);
 }
 EXPORT_SYMBOL(clkdev_add);

 void __init clkdev_add_table(struct clk_lookup *cl, size_t num)
 {
 	mutex_lock(&clocks_mutex);
 	while (num--) {
 		list_add_tail(&cl->node, &clocks);
 		cl++;
 	}
 	mutex_unlock(&clocks_mutex);
 }

 #define MAX_DEV_ID	20
 #define MAX_CON_ID	16

 struct clk_lookup_alloc {
 	struct clk_lookup cl;
 	char	dev_id[MAX_DEV_ID];
 	char	con_id[MAX_CON_ID];
 };

 static struct clk_lookup * __init_refok
 vclkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt,
 	va_list ap)
 {
 	struct clk_lookup_alloc *cla;

 	cla = __clkdev_alloc(sizeof(*cla));
 	if (!cla)
 		return NULL;

 	cla->cl.clk = clk;
 	if (con_id) {
 		strlcpy(cla->con_id, con_id, sizeof(cla->con_id));
 		cla->cl.con_id = cla->con_id;
 	}

 	if (dev_fmt) {
 		vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);
 		cla->cl.dev_id = cla->dev_id;
 	}

 	return &cla->cl;
 }

 struct clk_lookup * __init_refok
 clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...)
 {
 	struct clk_lookup *cl;
 	va_list ap;

 	va_start(ap, dev_fmt);
 	cl = vclkdev_alloc(clk, con_id, dev_fmt, ap);
 	va_end(ap);

 	return cl;
 }
 EXPORT_SYMBOL(clkdev_alloc);

 int clk_add_alias(const char *alias, const char *alias_dev_name, char *id,
 	struct device *dev)
 {
 	struct clk *r = clk_get(dev, id);
 	struct clk_lookup *l;

 	if (IS_ERR(r))
 		return PTR_ERR(r);

 	l = clkdev_alloc(r, alias, alias_dev_name);
 	clk_put(r);
 	if (!l)
 		return -ENODEV;
 	clkdev_add(l);
 	return 0;
 }
 EXPORT_SYMBOL(clk_add_alias);

 /*
  * clkdev_drop - remove a clock dynamically allocated
  */
 void clkdev_drop(struct clk_lookup *cl)
 {
 	mutex_lock(&clocks_mutex);
 	list_del(&cl->node);
 	mutex_unlock(&clocks_mutex);
 	kfree(cl);
 }
 EXPORT_SYMBOL(clkdev_drop);

 /**
  * clk_register_clkdev - register one clock lookup for a struct clk
  * @clk: struct clk to associate with all clk_lookups
  * @con_id: connection ID string on device
  * @dev_id: format string describing device name
  *
  * con_id or dev_id may be NULL as a wildcard, just as in the rest of
  * clkdev.
  *
  * To make things easier for mass registration, we detect error clks
  * from a previous clk_register() call, and return the error code for
  * those.  This is to permit this function to be called immediately
  * after clk_register().
  */
 int clk_register_clkdev(struct clk *clk, const char *con_id,
 	const char *dev_fmt, ...)
 {
 	struct clk_lookup *cl;
 	va_list ap;

 	if (IS_ERR(clk))
 		return PTR_ERR(clk);

 	va_start(ap, dev_fmt);
 	cl = vclkdev_alloc(clk, con_id, dev_fmt, ap);
 	va_end(ap);

 	if (!cl)
 		return -ENOMEM;

 	clkdev_add(cl);

 	return 0;
 }

 /**
  * clk_register_clkdevs - register a set of clk_lookup for a struct clk
  * @clk: struct clk to associate with all clk_lookups
  * @cl: array of clk_lookup structures with con_id and dev_id pre-initialized
  * @num: number of clk_lookup structures to register
  *
  * To make things easier for mass registration, we detect error clks
  * from a previous clk_register() call, and return the error code for
  * those.  This is to permit this function to be called immediately
  * after clk_register().
  */
 int clk_register_clkdevs(struct clk *clk, struct clk_lookup *cl, size_t num)
 {
 	unsigned i;

 	if (IS_ERR(clk))
 		return PTR_ERR(clk);

 	for (i = 0; i < num; i++, cl++) {
 		cl->clk = clk;
 		clkdev_add(cl);
 	}

 	return 0;
 }
 EXPORT_SYMBOL(clk_register_clkdevs);
	/*
	* drivers/clk/clkdev.c
	*
	* Copyright (C) 2008 Russell King.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	* Helper for the clk API to assist looking up a struct clk.
	*/
	#include <linux/module.h>
	#include <linux/kernel.h>
	#include <linux/device.h>
	#include <linux/list.h>
	#include <linux/errno.h>
	#include <linux/err.h>
	#include <linux/string.h>
	#include <linux/mutex.h>
	#include <linux/clk.h>
	#include <linux/clkdev.h>
	#include <linux/of.h>

	static LIST_HEAD(clocks);
	static DEFINE_MUTEX(clocks_mutex);

	#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
	struct clk of_clk_get(struct device_node np, int index)
	{
	struct of_phandle_args clkspec;
	struct clk *clk;
	int rc;

	if (index < 0)
	return ERR_PTR(-EINVAL);

	rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
	&clkspec);
	if (rc)
	return ERR_PTR(rc);

	clk = of_clk_get_from_provider(&clkspec);
	of_node_put(clkspec.np);
	return clk;
	}
	EXPORT_SYMBOL(of_clk_get);

	/**
	* of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
	* @np: pointer to clock consumer node
	* @name: name of consumer's clock input, or NULL for the first clock reference
	*
	* This function parses the clocks and clock-names properties,
	* and uses them to look up the struct clk from the registered list of clock
	* providers.
	*/
	struct clk of_clk_get_by_name(struct device_node np, const char *name)
	{
	struct clk *clk = ERR_PTR(-ENOENT);

	/* Walk up the tree of devices looking for a clock that matches */
	while (np) {
	int index = 0;

	/*
	* For named clocks, first look up the name in the
	* "clock-names" property. If it cannot be found, then
	* index will be an error code, and of_clk_get() will fail.
	*/
	if (name)
	index = of_property_match_string(np, "clock-names", name);
	clk = of_clk_get(np, index);
	if (!IS_ERR(clk))
	break;
	else if (name && index >= 0) {
	pr_err("ERROR: could not get clock %s:%s(%i)\n",
	np->full_name, name ? name : "", index);
	return clk;
	}

	/*
	* No matching clock found on this node. If the parent node
	* has a "clock-ranges" property, then we can try one of its
	* clocks.
	*/
	np = np->parent;
	if (np && !of_get_property(np, "clock-ranges", NULL))
	break;
	}

	return clk;
	}
	EXPORT_SYMBOL(of_clk_get_by_name);
	#endif

	/*
	* Find the correct struct clk for the device and connection ID.
	* We do slightly fuzzy matching here:
	* An entry with a NULL ID is assumed to be a wildcard.
	* If an entry has a device ID, it must match
	* If an entry has a connection ID, it must match
	* Then we take the most specific entry - with the following
	* order of precedence: dev+con > dev only > con only.
	*/
	static struct clk_lookup clk_find(const char dev_id, const char *con_id)
	{
	struct clk_lookup p, cl = NULL;
	int match, best_found = 0, best_possible = 0;

	if (dev_id)
	best_possible += 2;
	if (con_id)
	best_possible += 1;

	list_for_each_entry(p, &clocks, node) {
	match = 0;
	if (p->dev_id) {
	if (!dev_id \|\| strcmp(p->dev_id, dev_id))
	continue;
	match += 2;
	}
	if (p->con_id) {
	if (!con_id \|\| strcmp(p->con_id, con_id))
	continue;
	match += 1;
	}

	if (match > best_found) {
	cl = p;
	if (match != best_possible)
	best_found = match;
	else
	break;
	}
	}
	return cl;
	}

	struct clk clk_get_sys(const char dev_id, const char *con_id)
	{
	struct clk_lookup *cl;

	mutex_lock(&clocks_mutex);
	cl = clk_find(dev_id, con_id);
	if (cl && !__clk_get(cl->clk))
	cl = NULL;
	mutex_unlock(&clocks_mutex);

	return cl ? cl->clk : ERR_PTR(-ENOENT);
	}
	EXPORT_SYMBOL(clk_get_sys);

	struct clk clk_get(struct device dev, const char *con_id)
	{
	const char *dev_id = dev ? dev_name(dev) : NULL;
	struct clk *clk;

	if (dev) {
	clk = of_clk_get_by_name(dev->of_node, con_id);
	if (!IS_ERR(clk) && __clk_get(clk))
	return clk;
	}

	return clk_get_sys(dev_id, con_id);
	}
	EXPORT_SYMBOL(clk_get);

	void clk_put(struct clk *clk)
	{
	__clk_put(clk);
	}
	EXPORT_SYMBOL(clk_put);

	void clkdev_add(struct clk_lookup *cl)
	{
	mutex_lock(&clocks_mutex);
	list_add_tail(&cl->node, &clocks);
	mutex_unlock(&clocks_mutex);
	}
	EXPORT_SYMBOL(clkdev_add);

	void __init clkdev_add_table(struct clk_lookup *cl, size_t num)
	{
	mutex_lock(&clocks_mutex);
	while (num--) {
	list_add_tail(&cl->node, &clocks);
	cl++;
	}
	mutex_unlock(&clocks_mutex);
	}

	#define MAX_DEV_ID 20
	#define MAX_CON_ID 16

	struct clk_lookup_alloc {
	struct clk_lookup cl;
	char dev_id[MAX_DEV_ID];
	char con_id[MAX_CON_ID];
	};

	static struct clk_lookup * __init_refok
	vclkdev_alloc(struct clk clk, const char con_id, const char *dev_fmt,
	va_list ap)
	{
	struct clk_lookup_alloc *cla;

	cla = __clkdev_alloc(sizeof(*cla));
	if (!cla)
	return NULL;

	cla->cl.clk = clk;
	if (con_id) {
	strlcpy(cla->con_id, con_id, sizeof(cla->con_id));
	cla->cl.con_id = cla->con_id;
	}

	if (dev_fmt) {
	vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);
	cla->cl.dev_id = cla->dev_id;
	}

	return &cla->cl;
	}

	struct clk_lookup * __init_refok
	clkdev_alloc(struct clk clk, const char con_id, const char *dev_fmt, ...)
	{
	struct clk_lookup *cl;
	va_list ap;

	va_start(ap, dev_fmt);
	cl = vclkdev_alloc(clk, con_id, dev_fmt, ap);
	va_end(ap);

	return cl;
	}
	EXPORT_SYMBOL(clkdev_alloc);

	int clk_add_alias(const char alias, const char alias_dev_name, char *id,
	struct device *dev)
	{
	struct clk *r = clk_get(dev, id);
	struct clk_lookup *l;

	if (IS_ERR(r))
	return PTR_ERR(r);

	l = clkdev_alloc(r, alias, alias_dev_name);
	clk_put(r);
	if (!l)
	return -ENODEV;
	clkdev_add(l);
	return 0;
	}
	EXPORT_SYMBOL(clk_add_alias);

	/*
	* clkdev_drop - remove a clock dynamically allocated
	*/
	void clkdev_drop(struct clk_lookup *cl)
	{
	mutex_lock(&clocks_mutex);
	list_del(&cl->node);
	mutex_unlock(&clocks_mutex);
	kfree(cl);
	}
	EXPORT_SYMBOL(clkdev_drop);

	/**
	* clk_register_clkdev - register one clock lookup for a struct clk
	* @clk: struct clk to associate with all clk_lookups
	* @con_id: connection ID string on device
	* @dev_id: format string describing device name
	*
	* con_id or dev_id may be NULL as a wildcard, just as in the rest of
	* clkdev.
	*
	* To make things easier for mass registration, we detect error clks
	* from a previous clk_register() call, and return the error code for
	* those. This is to permit this function to be called immediately
	* after clk_register().
	*/
	int clk_register_clkdev(struct clk clk, const char con_id,
	const char *dev_fmt, ...)
	{
	struct clk_lookup *cl;
	va_list ap;

	if (IS_ERR(clk))
	return PTR_ERR(clk);

	va_start(ap, dev_fmt);
	cl = vclkdev_alloc(clk, con_id, dev_fmt, ap);
	va_end(ap);

	if (!cl)
	return -ENOMEM;

	clkdev_add(cl);

	return 0;
	}

	/**
	* clk_register_clkdevs - register a set of clk_lookup for a struct clk
	* @clk: struct clk to associate with all clk_lookups
	* @cl: array of clk_lookup structures with con_id and dev_id pre-initialized
	* @num: number of clk_lookup structures to register
	*
	* To make things easier for mass registration, we detect error clks
	* from a previous clk_register() call, and return the error code for
	* those. This is to permit this function to be called immediately
	* after clk_register().
	*/
	int clk_register_clkdevs(struct clk clk, struct clk_lookup cl, size_t num)
	{
	unsigned i;

	if (IS_ERR(clk))
	return PTR_ERR(clk);

	for (i = 0; i < num; i++, cl++) {
	cl->clk = clk;
	clkdev_add(cl);
	}

	return 0;
	}
	EXPORT_SYMBOL(clk_register_clkdevs);