[deliverable/linux.git] / drivers / base / regmap / regcache.c

/*
 * Register cache access API
 *
 * Copyright 2011 Wolfson Microelectronics plc
 *
 * Author: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
 *
 * 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.
 */

#include <linux/slab.h>
#include <trace/events/regmap.h>

#include "internal.h"

static const struct regcache_ops *cache_types[] = {
	&regcache_indexed_ops,
	&regcache_rbtree_ops,
	&regcache_lzo_ops,
};

static int regcache_hw_init(struct regmap *map)
{
	int i, j;
	int ret;
	int count;
	unsigned int val;
	void *tmp_buf;

	if (!map->num_reg_defaults_raw)
		return -EINVAL;

	if (!map->reg_defaults_raw) {
		dev_warn(map->dev, "No cache defaults, reading back from HW\n");
		tmp_buf = kmalloc(map->cache_size_raw, GFP_KERNEL);
		if (!tmp_buf)
			return -EINVAL;
		ret = regmap_bulk_read(map, 0, tmp_buf,
				       map->num_reg_defaults_raw);
		if (ret < 0) {
			kfree(tmp_buf);
			return ret;
		}
		map->reg_defaults_raw = tmp_buf;
		map->cache_free = 1;
	}

	/* calculate the size of reg_defaults */
	for (count = 0, i = 0; i < map->num_reg_defaults_raw; i++) {
		val = regcache_get_val(map->reg_defaults_raw,
				       i, map->cache_word_size);
		if (!val)
			continue;
		count++;
	}

	map->reg_defaults = kmalloc(count * sizeof(struct reg_default),
				      GFP_KERNEL);
	if (!map->reg_defaults)
		return -ENOMEM;

	/* fill the reg_defaults */
	map->num_reg_defaults = count;
	for (i = 0, j = 0; i < map->num_reg_defaults_raw; i++) {
		val = regcache_get_val(map->reg_defaults_raw,
				       i, map->cache_word_size);
		if (!val)
			continue;
		map->reg_defaults[j].reg = i;
		map->reg_defaults[j].def = val;
		j++;
	}

	return 0;
}

int regcache_init(struct regmap *map)
{
	int ret;
	int i;
	void *tmp_buf;

	if (map->cache_type == REGCACHE_NONE) {
		map->cache_bypass = true;
		return 0;
	}

	for (i = 0; i < ARRAY_SIZE(cache_types); i++)
		if (cache_types[i]->type == map->cache_type)
			break;

	if (i == ARRAY_SIZE(cache_types)) {
		dev_err(map->dev, "Could not match compress type: %d\n",
			map->cache_type);
		return -EINVAL;
	}

	map->cache = NULL;
	map->cache_ops = cache_types[i];

	if (!map->cache_ops->read ||
	    !map->cache_ops->write ||
	    !map->cache_ops->name)
		return -EINVAL;

	/* We still need to ensure that the reg_defaults
	 * won't vanish from under us.  We'll need to make
	 * a copy of it.
	 */
	if (map->reg_defaults) {
		if (!map->num_reg_defaults)
			return -EINVAL;
		tmp_buf = kmemdup(map->reg_defaults, map->num_reg_defaults *
				  sizeof(struct reg_default), GFP_KERNEL);
		if (!tmp_buf)
			return -ENOMEM;
		map->reg_defaults = tmp_buf;
	} else {
		/* Some devices such as PMIC's don't have cache defaults,
		 * we cope with this by reading back the HW registers and
		 * crafting the cache defaults by hand.
		 */
		ret = regcache_hw_init(map);
		if (ret < 0)
			return ret;
	}

	if (!map->max_register)
		map->max_register = map->num_reg_defaults_raw;

	if (map->cache_ops->init) {
		dev_dbg(map->dev, "Initializing %s cache\n",
			map->cache_ops->name);
		return map->cache_ops->init(map);
	}
	return 0;
}

void regcache_exit(struct regmap *map)
{
	if (map->cache_type == REGCACHE_NONE)
		return;

	BUG_ON(!map->cache_ops);

	kfree(map->reg_defaults);
	if (map->cache_free)
		kfree(map->reg_defaults_raw);

	if (map->cache_ops->exit) {
		dev_dbg(map->dev, "Destroying %s cache\n",
			map->cache_ops->name);
		map->cache_ops->exit(map);
	}
}

/**
 * regcache_read: Fetch the value of a given register from the cache.
 *
 * @map: map to configure.
 * @reg: The register index.
 * @value: The value to be returned.
 *
 * Return a negative value on failure, 0 on success.
 */
int regcache_read(struct regmap *map,
		  unsigned int reg, unsigned int *value)
{
	if (map->cache_type == REGCACHE_NONE)
		return -ENOSYS;

	BUG_ON(!map->cache_ops);

	if (!regmap_readable(map, reg))
		return -EIO;

	if (!regmap_volatile(map, reg))
		return map->cache_ops->read(map, reg, value);

	return -EINVAL;
}
EXPORT_SYMBOL_GPL(regcache_read);

/**
 * regcache_write: Set the value of a given register in the cache.
 *
 * @map: map to configure.
 * @reg: The register index.
 * @value: The new register value.
 *
 * Return a negative value on failure, 0 on success.
 */
int regcache_write(struct regmap *map,
		   unsigned int reg, unsigned int value)
{
	if (map->cache_type == REGCACHE_NONE)
		return 0;

	BUG_ON(!map->cache_ops);

	if (!regmap_writeable(map, reg))
		return -EIO;

	if (!regmap_volatile(map, reg))
		return map->cache_ops->write(map, reg, value);

	return 0;
}
EXPORT_SYMBOL_GPL(regcache_write);

/**
 * regcache_sync: Sync the register cache with the hardware.
 *
 * @map: map to configure.
 *
 * Any registers that should not be synced should be marked as
 * volatile.  In general drivers can choose not to use the provided
 * syncing functionality if they so require.
 *
 * Return a negative value on failure, 0 on success.
 */
int regcache_sync(struct regmap *map)
{
	int ret = 0;
	unsigned int val;
	unsigned int i;
	const char *name;

	BUG_ON(!map->cache_ops);

	dev_dbg(map->dev, "Syncing %s cache\n",
		map->cache_ops->name);
	name = map->cache_ops->name;
	trace_regcache_sync(map->dev, name, "start");
	if (map->cache_ops->sync) {
		ret = map->cache_ops->sync(map);
	} else {
		for (i = 0; i < map->num_reg_defaults; i++) {
			ret = regcache_read(map, i, &val);
			if (ret < 0)
				goto out;
			map->cache_bypass = 1;
			ret = regmap_write(map, i, val);
			map->cache_bypass = 0;
			if (ret < 0)
				goto out;
			dev_dbg(map->dev, "Synced register %#x, value %#x\n",
				map->reg_defaults[i].reg,
				map->reg_defaults[i].def);
		}

	}
out:
	trace_regcache_sync(map->dev, name, "stop");

	return ret;
}
EXPORT_SYMBOL_GPL(regcache_sync);

/**
 * regcache_cache_only: Put a register map into cache only mode
 *
 * @map: map to configure
 * @cache_only: flag if changes should be written to the hardware
 *
 * When a register map is marked as cache only writes to the register
 * map API will only update the register cache, they will not cause
 * any hardware changes.  This is useful for allowing portions of
 * drivers to act as though the device were functioning as normal when
 * it is disabled for power saving reasons.
 */
void regcache_cache_only(struct regmap *map, bool enable)
{
	mutex_lock(&map->sync_lock);
	map->cache_only = enable;
	mutex_unlock(&map->sync_lock);
}
EXPORT_SYMBOL_GPL(regcache_cache_only);

bool regcache_set_val(void *base, unsigned int idx,
		      unsigned int val, unsigned int word_size)
{
	switch (word_size) {
	case 1: {
		u8 *cache = base;
		if (cache[idx] == val)
			return true;
		cache[idx] = val;
		break;
	}
	case 2: {
		u16 *cache = base;
		if (cache[idx] == val)
			return true;
		cache[idx] = val;
		break;
	}
	default:
		BUG();
	}
	/* unreachable */
	return false;
}

unsigned int regcache_get_val(const void *base, unsigned int idx,
			      unsigned int word_size)
{
	if (!base)
		return -EINVAL;

	switch (word_size) {
	case 1: {
		const u8 *cache = base;
		return cache[idx];
	}
	case 2: {
		const u16 *cache = base;
		return cache[idx];
	}
	default:
		BUG();
	}
	/* unreachable */
	return -1;
}

int regcache_lookup_reg(struct regmap *map, unsigned int reg)
{
	unsigned int i;

	for (i = 0; i < map->num_reg_defaults; i++)
		if (map->reg_defaults[i].reg == reg)
			return i;
	return -1;
}

int regcache_insert_reg(struct regmap *map, unsigned int reg,
			unsigned int val)
{
	void *tmp;

	tmp = krealloc(map->reg_defaults,
		       (map->num_reg_defaults + 1) * sizeof(struct reg_default),
		       GFP_KERNEL);
	if (!tmp)
		return -ENOMEM;
	map->reg_defaults = tmp;
	map->num_reg_defaults++;
	map->reg_defaults[map->num_reg_defaults - 1].reg = reg;
	map->reg_defaults[map->num_reg_defaults - 1].def = val;
	return 0;
}
Commit	Line	Data
9fabe24e DP	1	/*
	2	* Register cache access API
	3	*
	4	* Copyright 2011 Wolfson Microelectronics plc
	5	*
	6	* Author: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*/
	12
	13	#include <linux/slab.h>
	14	#include <trace/events/regmap.h>
	15
	16	#include "internal.h"
	17
	18	static const struct regcache_ops *cache_types[] = {
195af65c	19	&regcache_indexed_ops,
28644c80	20	&regcache_rbtree_ops,
2cbbb579	21	&regcache_lzo_ops,
9fabe24e DP	22	};
	23
	24	static int regcache_hw_init(struct regmap *map)
	25	{
	26	int i, j;
	27	int ret;
	28	int count;
	29	unsigned int val;
	30	void *tmp_buf;
	31
	32	if (!map->num_reg_defaults_raw)
	33	return -EINVAL;
	34
	35	if (!map->reg_defaults_raw) {
	36	dev_warn(map->dev, "No cache defaults, reading back from HW\n");
	37	tmp_buf = kmalloc(map->cache_size_raw, GFP_KERNEL);
	38	if (!tmp_buf)
	39	return -EINVAL;
	40	ret = regmap_bulk_read(map, 0, tmp_buf,
	41	map->num_reg_defaults_raw);
	42	if (ret < 0) {
	43	kfree(tmp_buf);
	44	return ret;
	45	}
	46	map->reg_defaults_raw = tmp_buf;
	47	map->cache_free = 1;
	48	}
	49
	50	/* calculate the size of reg_defaults */
	51	for (count = 0, i = 0; i < map->num_reg_defaults_raw; i++) {
	52	val = regcache_get_val(map->reg_defaults_raw,
	53	i, map->cache_word_size);
	54	if (!val)
	55	continue;
	56	count++;
	57	}
	58
	59	map->reg_defaults = kmalloc(count * sizeof(struct reg_default),
	60	GFP_KERNEL);
	61	if (!map->reg_defaults)
	62	return -ENOMEM;
	63
	64	/* fill the reg_defaults */
	65	map->num_reg_defaults = count;
	66	for (i = 0, j = 0; i < map->num_reg_defaults_raw; i++) {
	67	val = regcache_get_val(map->reg_defaults_raw,
	68	i, map->cache_word_size);
	69	if (!val)
	70	continue;
	71	map->reg_defaults[j].reg = i;
	72	map->reg_defaults[j].def = val;
	73	j++;
	74	}
	75
	76	return 0;
	77	}
	78
	79	int regcache_init(struct regmap *map)
	80	{
	81	int ret;
	82	int i;
	83	void *tmp_buf;
	84
e7a6db30 MB	85	if (map->cache_type == REGCACHE_NONE) {
e7a6db30 MB	86	map->cache_bypass = true;
9fabe24e	87	return 0;
e7a6db30	88	}
9fabe24e DP	89
	90	for (i = 0; i < ARRAY_SIZE(cache_types); i++)
	91	if (cache_types[i]->type == map->cache_type)
	92	break;
	93
	94	if (i == ARRAY_SIZE(cache_types)) {
	95	dev_err(map->dev, "Could not match compress type: %d\n",
	96	map->cache_type);
	97	return -EINVAL;
	98	}
	99
	100	map->cache = NULL;
	101	map->cache_ops = cache_types[i];
	102
	103	if (!map->cache_ops->read \|\|
	104	!map->cache_ops->write \|\|
	105	!map->cache_ops->name)
	106	return -EINVAL;
	107
	108	/* We still need to ensure that the reg_defaults
	109	* won't vanish from under us. We'll need to make
	110	* a copy of it.
	111	*/
	112	if (map->reg_defaults) {
	113	if (!map->num_reg_defaults)
	114	return -EINVAL;
	115	tmp_buf = kmemdup(map->reg_defaults, map->num_reg_defaults *
	116	sizeof(struct reg_default), GFP_KERNEL);
	117	if (!tmp_buf)
	118	return -ENOMEM;
	119	map->reg_defaults = tmp_buf;
	120	} else {
	121	/* Some devices such as PMIC's don't have cache defaults,
	122	* we cope with this by reading back the HW registers and
	123	* crafting the cache defaults by hand.
	124	*/
	125	ret = regcache_hw_init(map);
	126	if (ret < 0)
	127	return ret;
	128	}
	129
	130	if (!map->max_register)
	131	map->max_register = map->num_reg_defaults_raw;
	132
	133	if (map->cache_ops->init) {
	134	dev_dbg(map->dev, "Initializing %s cache\n",
	135	map->cache_ops->name);
	136	return map->cache_ops->init(map);
	137	}
	138	return 0;
	139	}
	140
	141	void regcache_exit(struct regmap *map)
	142	{
	143	if (map->cache_type == REGCACHE_NONE)
	144	return;
	145
	146	BUG_ON(!map->cache_ops);
	147
	148	kfree(map->reg_defaults);
	149	if (map->cache_free)
	150	kfree(map->reg_defaults_raw);
	151
	152	if (map->cache_ops->exit) {
153	dev_dbg(map->dev, "Destroying %s cache\n",
154	map->cache_ops->name);
155	map->cache_ops->exit(map);
156	}
157	}
158
159	/**
160	* regcache_read: Fetch the value of a given register from the cache.
161	*
162	* @map: map to configure.
163	* @reg: The register index.
164	* @value: The value to be returned.
165	*
166	* Return a negative value on failure, 0 on success.
167	*/
168	int regcache_read(struct regmap *map,
169	unsigned int reg, unsigned int *value)
170	{
171	if (map->cache_type == REGCACHE_NONE)
172	return -ENOSYS;
173
174	BUG_ON(!map->cache_ops);
175
176	if (!regmap_readable(map, reg))
177	return -EIO;
178
179	if (!regmap_volatile(map, reg))
180	return map->cache_ops->read(map, reg, value);
181
182	return -EINVAL;
183	}
184	EXPORT_SYMBOL_GPL(regcache_read);
185
186	/**
187	* regcache_write: Set the value of a given register in the cache.
188	*
189	* @map: map to configure.
190	* @reg: The register index.
191	* @value: The new register value.
192	*
193	* Return a negative value on failure, 0 on success.
194	*/
195	int regcache_write(struct regmap *map,
196	unsigned int reg, unsigned int value)
197	{
198	if (map->cache_type == REGCACHE_NONE)
199	return 0;
200
201	BUG_ON(!map->cache_ops);
202
203	if (!regmap_writeable(map, reg))
204	return -EIO;
205
206	if (!regmap_volatile(map, reg))
207	return map->cache_ops->write(map, reg, value);
208
209	return 0;
210	}
211	EXPORT_SYMBOL_GPL(regcache_write);
212
213	/**
214	* regcache_sync: Sync the register cache with the hardware.
215	*
216	* @map: map to configure.
217	*
218	* Any registers that should not be synced should be marked as
219	* volatile. In general drivers can choose not to use the provided
220	* syncing functionality if they so require.
221	*
222	* Return a negative value on failure, 0 on success.
223	*/
224	int regcache_sync(struct regmap *map)
225	{
954757d7 DP	226	int ret = 0;
	227	unsigned int val;
	228	unsigned int i;
59360089 DP	229	const char *name;
59360089 DP	230
9fabe24e DP	231	BUG_ON(!map->cache_ops);
9fabe24e DP	232
954757d7 DP	233	dev_dbg(map->dev, "Syncing %s cache\n",
	234	map->cache_ops->name);
	235	name = map->cache_ops->name;
	236	trace_regcache_sync(map->dev, name, "start");
9fabe24e	237	if (map->cache_ops->sync) {
59360089	238	ret = map->cache_ops->sync(map);
954757d7 DP	239	} else {
	240	for (i = 0; i < map->num_reg_defaults; i++) {
	241	ret = regcache_read(map, i, &val);
	242	if (ret < 0)
	243	goto out;
ec8a365f	244	map->cache_bypass = 1;
a40c2823	245	ret = regmap_write(map, i, val);
ec8a365f	246	map->cache_bypass = 0;
954757d7 DP	247	if (ret < 0)
	248	goto out;
	249	dev_dbg(map->dev, "Synced register %#x, value %#x\n",
	250	map->reg_defaults[i].reg,
	251	map->reg_defaults[i].def);
	252	}
	253
9fabe24e	254	}
954757d7 DP	255	out:
	256	trace_regcache_sync(map->dev, name, "stop");
	257
	258	return ret;
9fabe24e DP	259	}
	260	EXPORT_SYMBOL_GPL(regcache_sync);
	261
92afb286 MB	262	/**
	263	* regcache_cache_only: Put a register map into cache only mode
	264	*
	265	* @map: map to configure
	266	* @cache_only: flag if changes should be written to the hardware
	267	*
	268	* When a register map is marked as cache only writes to the register
	269	* map API will only update the register cache, they will not cause
	270	* any hardware changes. This is useful for allowing portions of
	271	* drivers to act as though the device were functioning as normal when
	272	* it is disabled for power saving reasons.
	273	*/
	274	void regcache_cache_only(struct regmap *map, bool enable)
	275	{
38f69169	276	mutex_lock(&map->sync_lock);
92afb286	277	map->cache_only = enable;
38f69169	278	mutex_unlock(&map->sync_lock);
92afb286 MB	279	}
	280	EXPORT_SYMBOL_GPL(regcache_cache_only);
	281
9fabe24e DP	282	bool regcache_set_val(void *base, unsigned int idx,
	283	unsigned int val, unsigned int word_size)
	284	{
	285	switch (word_size) {
	286	case 1: {
	287	u8 *cache = base;
	288	if (cache[idx] == val)
	289	return true;
	290	cache[idx] = val;
	291	break;
	292	}
	293	case 2: {
	294	u16 *cache = base;
	295	if (cache[idx] == val)
	296	return true;
	297	cache[idx] = val;
	298	break;
	299	}
	300	default:
	301	BUG();
	302	}
	303	/* unreachable */
	304	return false;
	305	}
	306
	307	unsigned int regcache_get_val(const void *base, unsigned int idx,
	308	unsigned int word_size)
	309	{
	310	if (!base)
	311	return -EINVAL;
	312
	313	switch (word_size) {
	314	case 1: {
	315	const u8 *cache = base;
	316	return cache[idx];
	317	}
	318	case 2: {
	319	const u16 *cache = base;
	320	return cache[idx];
	321	}
	322	default:
	323	BUG();
	324	}
	325	/* unreachable */
	326	return -1;
	327	}
	328
	329	int regcache_lookup_reg(struct regmap *map, unsigned int reg)
	330	{
	331	unsigned int i;
	332
	333	for (i = 0; i < map->num_reg_defaults; i++)
	334	if (map->reg_defaults[i].reg == reg)
	335	return i;
	336	return -1;
	337	}
	338
	339	int regcache_insert_reg(struct regmap *map, unsigned int reg,
	340	unsigned int val)
	341	{
	342	void *tmp;
	343
	344	tmp = krealloc(map->reg_defaults,
	345	(map->num_reg_defaults + 1) * sizeof(struct reg_default),
346	GFP_KERNEL);
347	if (!tmp)
348	return -ENOMEM;
349	map->reg_defaults = tmp;
350	map->num_reg_defaults++;
351	map->reg_defaults[map->num_reg_defaults - 1].reg = reg;
352	map->reg_defaults[map->num_reg_defaults - 1].def = val;
353	return 0;
354	}