[deliverable/linux.git] / arch / arm / common / clkdev.c

/*
 *  arch/arm/common/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/slab.h>

#include <asm/clkdev.h>
#include <mach/clkdev.h>

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

/*
 * 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 *clk_find(const char *dev_id, const char *con_id)
{
	struct clk_lookup *p;
	struct clk *clk = NULL;
	int match, best = 0;

	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) {
			clk = p->clk;
			if (match != 3)
				best = match;
			else
				break;
		}
	}
	return clk;
}

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

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

	return clk ? 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;

	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];
};

struct clk_lookup *clkdev_alloc(struct clk *clk, const char *con_id,
	const char *dev_fmt, ...)
{
	struct clk_lookup_alloc *cla;

	cla = kzalloc(sizeof(*cla), GFP_KERNEL);
	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) {
		va_list ap;

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

	return &cla->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);
Commit	Line	Data
0318e693 RK	1	/*
	2	* arch/arm/common/clkdev.c
	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>
5a0e3ad6	21	#include <linux/slab.h>
0318e693 RK	22
	23	#include <asm/clkdev.h>
	24	#include <mach/clkdev.h>
	25
	26	static LIST_HEAD(clocks);
	27	static DEFINE_MUTEX(clocks_mutex);
	28
409dc360 RK	29	/*
	30	* Find the correct struct clk for the device and connection ID.
	31	* We do slightly fuzzy matching here:
	32	* An entry with a NULL ID is assumed to be a wildcard.
	33	* If an entry has a device ID, it must match
	34	* If an entry has a connection ID, it must match
	35	* Then we take the most specific entry - with the following
659431fc	36	* order of precedence: dev+con > dev only > con only.
409dc360	37	*/
0318e693 RK	38	static struct clk clk_find(const char dev_id, const char *con_id)
	39	{
	40	struct clk_lookup *p;
	41	struct clk *clk = NULL;
	42	int match, best = 0;
	43
	44	list_for_each_entry(p, &clocks, node) {
0318e693	45	match = 0;
409dc360 RK	46	if (p->dev_id) {
	47	if (!dev_id \|\| strcmp(p->dev_id, dev_id))
	48	continue;
	49	match += 2;
	50	}
	51	if (p->con_id) {
	52	if (!con_id \|\| strcmp(p->con_id, con_id))
	53	continue;
	54	match += 1;
	55	}
0318e693 RK	56
	57	if (match > best) {
	58	clk = p->clk;
e4bf5bec	59	if (match != 3)
	60	best = match;
	61	else
	62	break;
0318e693 RK	63	}
	64	}
	65	return clk;
	66	}
	67
05fd8e73	68	struct clk clk_get_sys(const char dev_id, const char *con_id)
0318e693	69	{
0318e693 RK	70	struct clk *clk;
	71
	72	mutex_lock(&clocks_mutex);
	73	clk = clk_find(dev_id, con_id);
	74	if (clk && !__clk_get(clk))
	75	clk = NULL;
	76	mutex_unlock(&clocks_mutex);
	77
	78	return clk ? clk : ERR_PTR(-ENOENT);
	79	}
05fd8e73 SH	80	EXPORT_SYMBOL(clk_get_sys);
	81
	82	struct clk clk_get(struct device dev, const char *con_id)
	83	{
	84	const char *dev_id = dev ? dev_name(dev) : NULL;
	85
	86	return clk_get_sys(dev_id, con_id);
	87	}
0318e693 RK	88	EXPORT_SYMBOL(clk_get);
	89
	90	void clk_put(struct clk *clk)
	91	{
	92	__clk_put(clk);
	93	}
	94	EXPORT_SYMBOL(clk_put);
	95
	96	void clkdev_add(struct clk_lookup *cl)
	97	{
	98	mutex_lock(&clocks_mutex);
	99	list_add_tail(&cl->node, &clocks);
	100	mutex_unlock(&clocks_mutex);
	101	}
	102	EXPORT_SYMBOL(clkdev_add);
	103
0a0300dc RK	104	void __init clkdev_add_table(struct clk_lookup *cl, size_t num)
	105	{
	106	mutex_lock(&clocks_mutex);
	107	while (num--) {
	108	list_add_tail(&cl->node, &clocks);
	109	cl++;
	110	}
	111	mutex_unlock(&clocks_mutex);
	112	}
	113
0318e693 RK	114	#define MAX_DEV_ID 20
	115	#define MAX_CON_ID 16
	116
	117	struct clk_lookup_alloc {
	118	struct clk_lookup cl;
	119	char dev_id[MAX_DEV_ID];
	120	char con_id[MAX_CON_ID];
	121	};
	122
	123	struct clk_lookup clkdev_alloc(struct clk clk, const char *con_id,
	124	const char *dev_fmt, ...)
	125	{
	126	struct clk_lookup_alloc *cla;
	127
	128	cla = kzalloc(sizeof(*cla), GFP_KERNEL);
	129	if (!cla)
	130	return NULL;
	131
	132	cla->cl.clk = clk;
	133	if (con_id) {
	134	strlcpy(cla->con_id, con_id, sizeof(cla->con_id));
	135	cla->cl.con_id = cla->con_id;
	136	}
	137
	138	if (dev_fmt) {
	139	va_list ap;
	140
	141	va_start(ap, dev_fmt);
	142	vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);
	143	cla->cl.dev_id = cla->dev_id;
	144	va_end(ap);
	145	}
	146
	147	return &cla->cl;
	148	}
	149	EXPORT_SYMBOL(clkdev_alloc);
	150
c0683039 TL	151	int clk_add_alias(const char alias, const char alias_dev_name, char *id,
	152	struct device *dev)
	153	{
	154	struct clk *r = clk_get(dev, id);
	155	struct clk_lookup *l;
	156
	157	if (IS_ERR(r))
	158	return PTR_ERR(r);
	159
	160	l = clkdev_alloc(r, alias, alias_dev_name);
	161	clk_put(r);
	162	if (!l)
	163	return -ENODEV;
	164	clkdev_add(l);
	165	return 0;
	166	}
	167	EXPORT_SYMBOL(clk_add_alias);
	168
0318e693 RK	169	/*
	170	* clkdev_drop - remove a clock dynamically allocated
	171	*/
	172	void clkdev_drop(struct clk_lookup *cl)
	173	{
	174	mutex_lock(&clocks_mutex);
	175	list_del(&cl->node);
	176	mutex_unlock(&clocks_mutex);
	177	kfree(cl);
	178	}
	179	EXPORT_SYMBOL(clkdev_drop);