[deliverable/linux.git] / drivers / clk / clkdev.c

/*
 * 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>

#include "clk.h"

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

#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)

/**
 * of_clk_get_by_clkspec() - Lookup a clock form a clock provider
 * @clkspec: pointer to a clock specifier data structure
 *
 * This function looks up a struct clk from the registered list of clock
 * providers, an input is a clock specifier data structure as returned
 * from the of_parse_phandle_with_args() function call.
 */
struct clk *of_clk_get_by_clkspec(struct of_phandle_args *clkspec)
{
	struct clk *clk;

	if (!clkspec)
		return ERR_PTR(-EINVAL);

	of_clk_lock();
	clk = __of_clk_get_from_provider(clkspec);

	if (!IS_ERR(clk) && !__clk_get(clk))
		clk = ERR_PTR(-ENOENT);

	of_clk_unlock();
	return 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_by_clkspec(&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) {
			if (PTR_ERR(clk) != -EPROBE_DEFER)
				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))
			return clk;
		if (PTR_ERR(clk) == -EPROBE_DEFER)
			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);
Commit	Line	Data
0318e693	1	/*
6d803ba7	2	* drivers/clk/clkdev.c
0318e693 RK	3	*
	4	* Copyright (C) 2008 Russell King.
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	* Helper for the clk API to assist looking up a struct clk.
	11	*/
	12	#include <linux/module.h>
	13	#include <linux/kernel.h>
	14	#include <linux/device.h>
	15	#include <linux/list.h>
	16	#include <linux/errno.h>
	17	#include <linux/err.h>
	18	#include <linux/string.h>
	19	#include <linux/mutex.h>
c0c60c4b	20	#include <linux/clk.h>
6d803ba7	21	#include <linux/clkdev.h>
766e6a4e	22	#include <linux/of.h>
0318e693	23
3a3d2b05 SN	24	#include "clk.h"
3a3d2b05 SN	25
0318e693 RK	26	static LIST_HEAD(clocks);
	27	static DEFINE_MUTEX(clocks_mutex);
	28
137f8a72	29	#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
7f05e28f SN	30
	31	/**
	32	* of_clk_get_by_clkspec() - Lookup a clock form a clock provider
	33	* @clkspec: pointer to a clock specifier data structure
	34	*
	35	* This function looks up a struct clk from the registered list of clock
	36	* providers, an input is a clock specifier data structure as returned
	37	* from the of_parse_phandle_with_args() function call.
	38	*/
	39	struct clk of_clk_get_by_clkspec(struct of_phandle_args clkspec)
	40	{
	41	struct clk *clk;
	42
	43	if (!clkspec)
	44	return ERR_PTR(-EINVAL);
	45
	46	of_clk_lock();
	47	clk = __of_clk_get_from_provider(clkspec);
	48
	49	if (!IS_ERR(clk) && !__clk_get(clk))
	50	clk = ERR_PTR(-ENOENT);
	51
	52	of_clk_unlock();
	53	return clk;
	54	}
	55
766e6a4e GL	56	struct clk of_clk_get(struct device_node np, int index)
	57	{
	58	struct of_phandle_args clkspec;
	59	struct clk *clk;
	60	int rc;
	61
	62	if (index < 0)
	63	return ERR_PTR(-EINVAL);
	64
	65	rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
	66	&clkspec);
	67	if (rc)
	68	return ERR_PTR(rc);
	69
7f05e28f	70	clk = of_clk_get_by_clkspec(&clkspec);
766e6a4e GL	71	of_node_put(clkspec.np);
	72	return clk;
	73	}
	74	EXPORT_SYMBOL(of_clk_get);
	75
	76	/**
	77	* of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
	78	* @np: pointer to clock consumer node
	79	* @name: name of consumer's clock input, or NULL for the first clock reference
	80	*
	81	* This function parses the clocks and clock-names properties,
	82	* and uses them to look up the struct clk from the registered list of clock
	83	* providers.
	84	*/
	85	struct clk of_clk_get_by_name(struct device_node np, const char *name)
	86	{
	87	struct clk *clk = ERR_PTR(-ENOENT);
	88
	89	/* Walk up the tree of devices looking for a clock that matches */
	90	while (np) {
	91	int index = 0;
	92
	93	/*
	94	* For named clocks, first look up the name in the
	95	* "clock-names" property. If it cannot be found, then
	96	* index will be an error code, and of_clk_get() will fail.
	97	*/
	98	if (name)
	99	index = of_property_match_string(np, "clock-names", name);
	100	clk = of_clk_get(np, index);
	101	if (!IS_ERR(clk))
	102	break;
	103	else if (name && index >= 0) {
d8e53c3d SB	104	if (PTR_ERR(clk) != -EPROBE_DEFER)
	105	pr_err("ERROR: could not get clock %s:%s(%i)\n",
	106	np->full_name, name ? name : "", index);
766e6a4e GL	107	return clk;
	108	}
	109
	110	/*
	111	* No matching clock found on this node. If the parent node
	112	* has a "clock-ranges" property, then we can try one of its
	113	* clocks.
	114	*/
	115	np = np->parent;
	116	if (np && !of_get_property(np, "clock-ranges", NULL))
	117	break;
	118	}
	119
	120	return clk;
	121	}
	122	EXPORT_SYMBOL(of_clk_get_by_name);
	123	#endif
	124
409dc360 RK	125	/*
	126	* Find the correct struct clk for the device and connection ID.
	127	* We do slightly fuzzy matching here:
	128	* An entry with a NULL ID is assumed to be a wildcard.
	129	* If an entry has a device ID, it must match
	130	* If an entry has a connection ID, it must match
	131	* Then we take the most specific entry - with the following
659431fc	132	* order of precedence: dev+con > dev only > con only.
409dc360	133	*/
e8bf8df9	134	static struct clk_lookup clk_find(const char dev_id, const char *con_id)
0318e693	135	{
e8bf8df9	136	struct clk_lookup p, cl = NULL;
67b50871	137	int match, best_found = 0, best_possible = 0;
	138
	139	if (dev_id)
	140	best_possible += 2;
	141	if (con_id)
	142	best_possible += 1;
0318e693 RK	143
0318e693 RK	144	list_for_each_entry(p, &clocks, node) {
0318e693	145	match = 0;
409dc360 RK	146	if (p->dev_id) {
	147	if (!dev_id \|\| strcmp(p->dev_id, dev_id))
	148	continue;
	149	match += 2;
	150	}
	151	if (p->con_id) {
	152	if (!con_id \|\| strcmp(p->con_id, con_id))
	153	continue;
	154	match += 1;
	155	}
0318e693	156
67b50871	157	if (match > best_found) {
e8bf8df9	158	cl = p;
67b50871	159	if (match != best_possible)
67b50871	160	best_found = match;
e4bf5bec	161	else
e4bf5bec	162	break;
0318e693 RK	163	}
0318e693 RK	164	}
e8bf8df9	165	return cl;
0318e693 RK	166	}
0318e693 RK	167
05fd8e73	168	struct clk clk_get_sys(const char dev_id, const char *con_id)
0318e693	169	{
e8bf8df9	170	struct clk_lookup *cl;
0318e693 RK	171
0318e693 RK	172	mutex_lock(&clocks_mutex);
e8bf8df9 RK	173	cl = clk_find(dev_id, con_id);
	174	if (cl && !__clk_get(cl->clk))
	175	cl = NULL;
0318e693 RK	176	mutex_unlock(&clocks_mutex);
0318e693 RK	177
e8bf8df9	178	return cl ? cl->clk : ERR_PTR(-ENOENT);
0318e693	179	}
05fd8e73 SH	180	EXPORT_SYMBOL(clk_get_sys);
	181
	182	struct clk clk_get(struct device dev, const char *con_id)
	183	{
	184	const char *dev_id = dev ? dev_name(dev) : NULL;
766e6a4e GL	185	struct clk *clk;
	186
	187	if (dev) {
	188	clk = of_clk_get_by_name(dev->of_node, con_id);
3a3d2b05	189	if (!IS_ERR(clk))
766e6a4e	190	return clk;
a34cd466 JFM	191	if (PTR_ERR(clk) == -EPROBE_DEFER)
a34cd466 JFM	192	return clk;
766e6a4e	193	}
05fd8e73 SH	194
	195	return clk_get_sys(dev_id, con_id);
	196	}
0318e693 RK	197	EXPORT_SYMBOL(clk_get);
	198
	199	void clk_put(struct clk *clk)
	200	{
	201	__clk_put(clk);
	202	}
	203	EXPORT_SYMBOL(clk_put);
	204
	205	void clkdev_add(struct clk_lookup *cl)
	206	{
	207	mutex_lock(&clocks_mutex);
	208	list_add_tail(&cl->node, &clocks);
	209	mutex_unlock(&clocks_mutex);
	210	}
	211	EXPORT_SYMBOL(clkdev_add);
	212
0a0300dc RK	213	void __init clkdev_add_table(struct clk_lookup *cl, size_t num)
	214	{
	215	mutex_lock(&clocks_mutex);
	216	while (num--) {
	217	list_add_tail(&cl->node, &clocks);
	218	cl++;
	219	}
	220	mutex_unlock(&clocks_mutex);
	221	}
	222
0318e693 RK	223	#define MAX_DEV_ID 20
	224	#define MAX_CON_ID 16
	225
	226	struct clk_lookup_alloc {
	227	struct clk_lookup cl;
	228	char dev_id[MAX_DEV_ID];
	229	char con_id[MAX_CON_ID];
	230	};
	231
e9d7f406 RK	232	static struct clk_lookup * __init_refok
	233	vclkdev_alloc(struct clk clk, const char con_id, const char *dev_fmt,
	234	va_list ap)
0318e693 RK	235	{
	236	struct clk_lookup_alloc *cla;
	237
6d803ba7	238	cla = __clkdev_alloc(sizeof(*cla));
0318e693 RK	239	if (!cla)
	240	return NULL;
	241
	242	cla->cl.clk = clk;
	243	if (con_id) {
	244	strlcpy(cla->con_id, con_id, sizeof(cla->con_id));
	245	cla->cl.con_id = cla->con_id;
	246	}
	247
	248	if (dev_fmt) {
0318e693 RK	249	vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);
0318e693 RK	250	cla->cl.dev_id = cla->dev_id;
0318e693 RK	251	}
	252
	253	return &cla->cl;
	254	}
e9d7f406 RK	255
	256	struct clk_lookup * __init_refok
	257	clkdev_alloc(struct clk clk, const char con_id, const char *dev_fmt, ...)
	258	{
	259	struct clk_lookup *cl;
	260	va_list ap;
	261
	262	va_start(ap, dev_fmt);
	263	cl = vclkdev_alloc(clk, con_id, dev_fmt, ap);
	264	va_end(ap);
	265
	266	return cl;
	267	}
0318e693 RK	268	EXPORT_SYMBOL(clkdev_alloc);
0318e693 RK	269
c0683039 TL	270	int clk_add_alias(const char alias, const char alias_dev_name, char *id,
	271	struct device *dev)
	272	{
	273	struct clk *r = clk_get(dev, id);
	274	struct clk_lookup *l;
	275
	276	if (IS_ERR(r))
	277	return PTR_ERR(r);
	278
	279	l = clkdev_alloc(r, alias, alias_dev_name);
	280	clk_put(r);
	281	if (!l)
	282	return -ENODEV;
	283	clkdev_add(l);
	284	return 0;
	285	}
	286	EXPORT_SYMBOL(clk_add_alias);
	287
0318e693 RK	288	/*
	289	* clkdev_drop - remove a clock dynamically allocated
	290	*/
	291	void clkdev_drop(struct clk_lookup *cl)
	292	{
	293	mutex_lock(&clocks_mutex);
	294	list_del(&cl->node);
	295	mutex_unlock(&clocks_mutex);
	296	kfree(cl);
	297	}
	298	EXPORT_SYMBOL(clkdev_drop);
e9d7f406 RK	299
	300	/**
	301	* clk_register_clkdev - register one clock lookup for a struct clk
	302	* @clk: struct clk to associate with all clk_lookups
	303	* @con_id: connection ID string on device
	304	* @dev_id: format string describing device name
	305	*
	306	* con_id or dev_id may be NULL as a wildcard, just as in the rest of
	307	* clkdev.
	308	*
	309	* To make things easier for mass registration, we detect error clks
	310	* from a previous clk_register() call, and return the error code for
	311	* those. This is to permit this function to be called immediately
	312	* after clk_register().
	313	*/
	314	int clk_register_clkdev(struct clk clk, const char con_id,
	315	const char *dev_fmt, ...)
	316	{
	317	struct clk_lookup *cl;
	318	va_list ap;
	319
	320	if (IS_ERR(clk))
	321	return PTR_ERR(clk);
	322
	323	va_start(ap, dev_fmt);
	324	cl = vclkdev_alloc(clk, con_id, dev_fmt, ap);
	325	va_end(ap);
	326
	327	if (!cl)
	328	return -ENOMEM;
	329
	330	clkdev_add(cl);
	331
	332	return 0;
	333	}
	334
	335	/**
	336	* clk_register_clkdevs - register a set of clk_lookup for a struct clk
	337	* @clk: struct clk to associate with all clk_lookups
	338	* @cl: array of clk_lookup structures with con_id and dev_id pre-initialized
	339	* @num: number of clk_lookup structures to register
	340	*
	341	* To make things easier for mass registration, we detect error clks
	342	* from a previous clk_register() call, and return the error code for
	343	* those. This is to permit this function to be called immediately
	344	* after clk_register().
	345	*/
	346	int clk_register_clkdevs(struct clk clk, struct clk_lookup cl, size_t num)
	347	{
	348	unsigned i;
	349
	350	if (IS_ERR(clk))
	351	return PTR_ERR(clk);
	352
	353	for (i = 0; i < num; i++, cl++) {
	354	cl->clk = clk;
	355	clkdev_add(cl);
	356	}
	357
	358	return 0;
	359	}
	360	EXPORT_SYMBOL(clk_register_clkdevs);