[mirror_ubuntu-artful-kernel.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/clk-provider.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)
static struct clk *__of_clk_get(struct device_node *np, int index,
			       const char *dev_id, const char *con_id)
{
	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, dev_id, con_id);
	of_node_put(clkspec.np);

	return clk;
}

struct clk *of_clk_get(struct device_node *np, int index)
{
	return __of_clk_get(np, index, np->full_name, NULL);
}
EXPORT_SYMBOL(of_clk_get);

static struct clk *__of_clk_get_by_name(struct device_node *np,
					const char *dev_id,
					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, dev_id, name);
		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;
}

/**
 * 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)
{
	if (!np)
		return ERR_PTR(-ENOENT);

	return __of_clk_get_by_name(np, np->full_name, name);
}
EXPORT_SYMBOL(of_clk_get_by_name);

#else /* defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK) */

static struct clk *__of_clk_get_by_name(struct device_node *np,
					const char *dev_id,
					const char *name)
{
	return ERR_PTR(-ENOENT);
}
#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;
	struct clk *clk = NULL;

	mutex_lock(&clocks_mutex);

	cl = clk_find(dev_id, con_id);
	if (!cl)
		goto out;

	clk = __clk_create_clk(__clk_get_hw(cl->clk), dev_id, con_id);
	if (IS_ERR(clk))
		goto out;

	if (!__clk_get(clk)) {
		__clk_free_clk(clk);
		cl = NULL;
		goto out;
	}

out:
	mutex_unlock(&clocks_mutex);

	return 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, dev_id, con_id);
		if (!IS_ERR(clk) || 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;
}
EXPORT_SYMBOL(clk_register_clkdev);

/**
 * 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>
035a61c3	22	#include <linux/clk-provider.h>
766e6a4e	23	#include <linux/of.h>
0318e693	24
3a3d2b05 SN	25	#include "clk.h"
3a3d2b05 SN	26
0318e693 RK	27	static LIST_HEAD(clocks);
	28	static DEFINE_MUTEX(clocks_mutex);
	29
137f8a72	30	#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
73e0e496 SB	31	static struct clk __of_clk_get(struct device_node np, int index,
73e0e496 SB	32	const char dev_id, const char con_id)
766e6a4e GL	33	{
	34	struct of_phandle_args clkspec;
	35	struct clk *clk;
	36	int rc;
	37
	38	if (index < 0)
	39	return ERR_PTR(-EINVAL);
	40
	41	rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
	42	&clkspec);
	43	if (rc)
	44	return ERR_PTR(rc);
	45
306c342f	46	clk = __of_clk_get_from_provider(&clkspec, dev_id, con_id);
766e6a4e	47	of_node_put(clkspec.np);
035a61c3 TV	48
	49	return clk;
	50	}
	51
	52	struct clk of_clk_get(struct device_node np, int index)
	53	{
73e0e496	54	return __of_clk_get(np, index, np->full_name, NULL);
766e6a4e GL	55	}
	56	EXPORT_SYMBOL(of_clk_get);
	57
035a61c3 TV	58	static struct clk __of_clk_get_by_name(struct device_node np,
	59	const char *dev_id,
	60	const char *name)
766e6a4e GL	61	{
	62	struct clk *clk = ERR_PTR(-ENOENT);
	63
	64	/* Walk up the tree of devices looking for a clock that matches */
	65	while (np) {
	66	int index = 0;
	67
	68	/*
	69	* For named clocks, first look up the name in the
	70	* "clock-names" property. If it cannot be found, then
	71	* index will be an error code, and of_clk_get() will fail.
	72	*/
	73	if (name)
	74	index = of_property_match_string(np, "clock-names", name);
73e0e496	75	clk = __of_clk_get(np, index, dev_id, name);
035a61c3	76	if (!IS_ERR(clk)) {
766e6a4e	77	break;
73e0e496	78	} else if (name && index >= 0) {
d8e53c3d SB	79	if (PTR_ERR(clk) != -EPROBE_DEFER)
	80	pr_err("ERROR: could not get clock %s:%s(%i)\n",
	81	np->full_name, name ? name : "", index);
766e6a4e GL	82	return clk;
	83	}
	84
	85	/*
	86	* No matching clock found on this node. If the parent node
	87	* has a "clock-ranges" property, then we can try one of its
	88	* clocks.
	89	*/
	90	np = np->parent;
	91	if (np && !of_get_property(np, "clock-ranges", NULL))
	92	break;
	93	}
	94
	95	return clk;
	96	}
035a61c3 TV	97
	98	/**
	99	* of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
	100	* @np: pointer to clock consumer node
	101	* @name: name of consumer's clock input, or NULL for the first clock reference
	102	*
	103	* This function parses the clocks and clock-names properties,
	104	* and uses them to look up the struct clk from the registered list of clock
	105	* providers.
	106	*/
	107	struct clk of_clk_get_by_name(struct device_node np, const char *name)
	108	{
	109	if (!np)
	110	return ERR_PTR(-ENOENT);
	111
	112	return __of_clk_get_by_name(np, np->full_name, name);
	113	}
766e6a4e	114	EXPORT_SYMBOL(of_clk_get_by_name);
035a61c3 TV	115
	116	#else /* defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK) */
	117
	118	static struct clk __of_clk_get_by_name(struct device_node np,
	119	const char *dev_id,
	120	const char *name)
	121	{
	122	return ERR_PTR(-ENOENT);
	123	}
766e6a4e GL	124	#endif
766e6a4e GL	125
409dc360 RK	126	/*
	127	* Find the correct struct clk for the device and connection ID.
	128	* We do slightly fuzzy matching here:
	129	* An entry with a NULL ID is assumed to be a wildcard.
	130	* If an entry has a device ID, it must match
	131	* If an entry has a connection ID, it must match
	132	* Then we take the most specific entry - with the following
659431fc	133	* order of precedence: dev+con > dev only > con only.
409dc360	134	*/
e8bf8df9	135	static struct clk_lookup clk_find(const char dev_id, const char *con_id)
0318e693	136	{
e8bf8df9	137	struct clk_lookup p, cl = NULL;
67b50871 VK	138	int match, best_found = 0, best_possible = 0;
	139
	140	if (dev_id)
	141	best_possible += 2;
	142	if (con_id)
	143	best_possible += 1;
0318e693 RK	144
0318e693 RK	145	list_for_each_entry(p, &clocks, node) {
0318e693	146	match = 0;
409dc360 RK	147	if (p->dev_id) {
	148	if (!dev_id \|\| strcmp(p->dev_id, dev_id))
	149	continue;
	150	match += 2;
	151	}
	152	if (p->con_id) {
	153	if (!con_id \|\| strcmp(p->con_id, con_id))
	154	continue;
	155	match += 1;
	156	}
0318e693	157
67b50871	158	if (match > best_found) {
e8bf8df9	159	cl = p;
67b50871 VK	160	if (match != best_possible)
67b50871 VK	161	best_found = match;
e4bf5bec VK	162	else
e4bf5bec VK	163	break;
0318e693 RK	164	}
0318e693 RK	165	}
e8bf8df9	166	return cl;
0318e693 RK	167	}
0318e693 RK	168
05fd8e73	169	struct clk clk_get_sys(const char dev_id, const char *con_id)
0318e693	170	{
e8bf8df9	171	struct clk_lookup *cl;
035a61c3	172	struct clk *clk = NULL;
0318e693 RK	173
0318e693 RK	174	mutex_lock(&clocks_mutex);
035a61c3	175
e8bf8df9	176	cl = clk_find(dev_id, con_id);
035a61c3 TV	177	if (!cl)
	178	goto out;
	179
73e0e496 SB	180	clk = __clk_create_clk(__clk_get_hw(cl->clk), dev_id, con_id);
	181	if (IS_ERR(clk))
	182	goto out;
	183
	184	if (!__clk_get(clk)) {
	185	__clk_free_clk(clk);
e8bf8df9	186	cl = NULL;
035a61c3 TV	187	goto out;
	188	}
	189
035a61c3	190	out:
0318e693 RK	191	mutex_unlock(&clocks_mutex);
0318e693 RK	192
035a61c3	193	return cl ? clk : ERR_PTR(-ENOENT);
0318e693	194	}
05fd8e73 SH	195	EXPORT_SYMBOL(clk_get_sys);
	196
	197	struct clk clk_get(struct device dev, const char *con_id)
	198	{
	199	const char *dev_id = dev ? dev_name(dev) : NULL;
766e6a4e GL	200	struct clk *clk;
	201
	202	if (dev) {
035a61c3 TV	203	clk = __of_clk_get_by_name(dev->of_node, dev_id, con_id);
035a61c3 TV	204	if (!IS_ERR(clk) \|\| PTR_ERR(clk) == -EPROBE_DEFER)
a34cd466	205	return clk;
766e6a4e	206	}
05fd8e73 SH	207
	208	return clk_get_sys(dev_id, con_id);
	209	}
0318e693 RK	210	EXPORT_SYMBOL(clk_get);
	211
	212	void clk_put(struct clk *clk)
	213	{
	214	__clk_put(clk);
	215	}
	216	EXPORT_SYMBOL(clk_put);
	217
	218	void clkdev_add(struct clk_lookup *cl)
	219	{
	220	mutex_lock(&clocks_mutex);
	221	list_add_tail(&cl->node, &clocks);
	222	mutex_unlock(&clocks_mutex);
	223	}
	224	EXPORT_SYMBOL(clkdev_add);
	225
0a0300dc RK	226	void __init clkdev_add_table(struct clk_lookup *cl, size_t num)
	227	{
	228	mutex_lock(&clocks_mutex);
	229	while (num--) {
	230	list_add_tail(&cl->node, &clocks);
	231	cl++;
	232	}
	233	mutex_unlock(&clocks_mutex);
	234	}
	235
0318e693 RK	236	#define MAX_DEV_ID 20
	237	#define MAX_CON_ID 16
	238
	239	struct clk_lookup_alloc {
	240	struct clk_lookup cl;
	241	char dev_id[MAX_DEV_ID];
	242	char con_id[MAX_CON_ID];
	243	};
	244
e9d7f406 RK	245	static struct clk_lookup * __init_refok
	246	vclkdev_alloc(struct clk clk, const char con_id, const char *dev_fmt,
	247	va_list ap)
0318e693 RK	248	{
	249	struct clk_lookup_alloc *cla;
	250
6d803ba7	251	cla = __clkdev_alloc(sizeof(*cla));
0318e693 RK	252	if (!cla)
	253	return NULL;
	254
	255	cla->cl.clk = clk;
	256	if (con_id) {
	257	strlcpy(cla->con_id, con_id, sizeof(cla->con_id));
	258	cla->cl.con_id = cla->con_id;
	259	}
	260
	261	if (dev_fmt) {
0318e693 RK	262	vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);
0318e693 RK	263	cla->cl.dev_id = cla->dev_id;
0318e693 RK	264	}
	265
	266	return &cla->cl;
	267	}
e9d7f406 RK	268
	269	struct clk_lookup * __init_refok
	270	clkdev_alloc(struct clk clk, const char con_id, const char *dev_fmt, ...)
	271	{
	272	struct clk_lookup *cl;
	273	va_list ap;
	274
	275	va_start(ap, dev_fmt);
	276	cl = vclkdev_alloc(clk, con_id, dev_fmt, ap);
	277	va_end(ap);
	278
	279	return cl;
	280	}
0318e693 RK	281	EXPORT_SYMBOL(clkdev_alloc);
0318e693 RK	282
c0683039 TL	283	int clk_add_alias(const char alias, const char alias_dev_name, char *id,
	284	struct device *dev)
	285	{
	286	struct clk *r = clk_get(dev, id);
	287	struct clk_lookup *l;
	288
	289	if (IS_ERR(r))
	290	return PTR_ERR(r);
	291
	292	l = clkdev_alloc(r, alias, alias_dev_name);
	293	clk_put(r);
	294	if (!l)
	295	return -ENODEV;
	296	clkdev_add(l);
	297	return 0;
	298	}
	299	EXPORT_SYMBOL(clk_add_alias);
	300
0318e693 RK	301	/*
	302	* clkdev_drop - remove a clock dynamically allocated
	303	*/
	304	void clkdev_drop(struct clk_lookup *cl)
	305	{
	306	mutex_lock(&clocks_mutex);
	307	list_del(&cl->node);
	308	mutex_unlock(&clocks_mutex);
	309	kfree(cl);
	310	}
	311	EXPORT_SYMBOL(clkdev_drop);
e9d7f406 RK	312
	313	/**
	314	* clk_register_clkdev - register one clock lookup for a struct clk
	315	* @clk: struct clk to associate with all clk_lookups
	316	* @con_id: connection ID string on device
	317	* @dev_id: format string describing device name
	318	*
	319	* con_id or dev_id may be NULL as a wildcard, just as in the rest of
	320	* clkdev.
	321	*
	322	* To make things easier for mass registration, we detect error clks
	323	* from a previous clk_register() call, and return the error code for
	324	* those. This is to permit this function to be called immediately
	325	* after clk_register().
	326	*/
	327	int clk_register_clkdev(struct clk clk, const char con_id,
	328	const char *dev_fmt, ...)
	329	{
	330	struct clk_lookup *cl;
	331	va_list ap;
	332
	333	if (IS_ERR(clk))
	334	return PTR_ERR(clk);
	335
	336	va_start(ap, dev_fmt);
	337	cl = vclkdev_alloc(clk, con_id, dev_fmt, ap);
	338	va_end(ap);
	339
	340	if (!cl)
	341	return -ENOMEM;
	342
	343	clkdev_add(cl);
	344
	345	return 0;
	346	}
a251361a	347	EXPORT_SYMBOL(clk_register_clkdev);
e9d7f406 RK	348
	349	/**
	350	* clk_register_clkdevs - register a set of clk_lookup for a struct clk
	351	* @clk: struct clk to associate with all clk_lookups
	352	* @cl: array of clk_lookup structures with con_id and dev_id pre-initialized
	353	* @num: number of clk_lookup structures to register
	354	*
	355	* To make things easier for mass registration, we detect error clks
	356	* from a previous clk_register() call, and return the error code for
	357	* those. This is to permit this function to be called immediately
	358	* after clk_register().
	359	*/
	360	int clk_register_clkdevs(struct clk clk, struct clk_lookup cl, size_t num)
	361	{
	362	unsigned i;
	363
	364	if (IS_ERR(clk))
	365	return PTR_ERR(clk);
	366
	367	for (i = 0; i < num; i++, cl++) {
	368	cl->clk = clk;
	369	clkdev_add(cl);
	370	}
	371
	372	return 0;
	373	}
	374	EXPORT_SYMBOL(clk_register_clkdevs);