/* * Register map access API * * Copyright 2011 Wolfson Microelectronics plc * * Author: Mark Brown <broonie@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 <linux/module.h>#include <linux/mutex.h>#include <linux/err.h> #include <linux/regmap.h> struct regmap; struct regmap_format {	size_t buf_size;	size_t reg_bytes;	size_t val_bytes;	void (*format_write)(struct regmap *map,			     unsigned int reg, unsigned int val);	void (*format_reg)(void *buf, unsigned int reg);	void (*format_val)(void *buf, unsigned int val);	unsigned int (*parse_val)(void *buf);}; struct regmap {	struct mutex lock; 	struct device *dev; /* Device we do I/O on */	void *work_buf;     /* Scratch buffer used to format I/O */	struct regmap_format format;  /* Buffer format */	const struct regmap_bus *bus;}; static void regmap_format_4_12_write(struct regmap *map,				     unsigned int reg, unsigned int val){	__be16 *out = map->work_buf;	*out = cpu_to_be16((reg << 12) | val);} static void regmap_format_7_9_write(struct regmap *map,				    unsigned int reg, unsigned int val){	__be16 *out = map->work_buf;	*out = cpu_to_be16((reg << 9) | val);} static void regmap_format_8(void *buf, unsigned int val){	u8 *b = buf; 	b[0] = val;} static void regmap_format_16(void *buf, unsigned int val){	__be16 *b = buf; 	b[0] = cpu_to_be16(val);} static unsigned int regmap_parse_8(void *buf){	u8 *b = buf; 	return b[0];} static unsigned int regmap_parse_16(void *buf){	__be16 *b = buf; 	b[0] = be16_to_cpu(b[0]); 	return b[0];} /** * regmap_init(): Initialise register map * * @dev: Device that will be interacted with * @bus: Bus-specific callbacks to use with device * @config: Configuration for register map * * The return value will be an ERR_PTR() on error or a valid pointer to * a struct regmap.  This function should generally not be called * directly, it should be called by bus-specific init functions. */struct regmap *regmap_init(struct device *dev,			   const struct regmap_bus *bus,			   const struct regmap_config *config){	struct regmap *map;	int ret = -EINVAL; 	if (!bus || !config)		return NULL; 	map = kzalloc(sizeof(*map), GFP_KERNEL);	if (map == NULL) {		ret = -ENOMEM;		goto err;	} 	mutex_init(&map->lock);	map->format.buf_size = (config->reg_bits + config->val_bits) / 8;	map->format.reg_bytes = config->reg_bits / 8;	map->format.val_bytes = config->val_bits / 8;	map->dev = dev;	map->bus = bus; 	switch (config->reg_bits) {	case 4:		switch (config->val_bits) {		case 12:			map->format.format_write = regmap_format_4_12_write;			break;		default:			goto err_map;		}		break; 	case 7:		switch (config->val_bits) {		case 9:			map->format.format_write = regmap_format_7_9_write;			break;		default:			goto err_map;		}		break; 	case 8:		map->format.format_reg = regmap_format_8;		break; 	case 16:		map->format.format_reg = regmap_format_16;		break; 	default:		goto err_map;	} 	switch (config->val_bits) {	case 8:		map->format.format_val = regmap_format_8;		map->format.parse_val = regmap_parse_8;		break;	case 16:		map->format.format_val = regmap_format_16;		map->format.parse_val = regmap_parse_16;		break;	} 	if (!map->format.format_write &&	    !(map->format.format_reg && map->format.format_val))		goto err_map; 	map->work_buf = kmalloc(map->format.buf_size, GFP_KERNEL);	if (map->work_buf == NULL) {		ret = -ENOMEM;		goto err_map;	} 	return map; err_map:	kfree(map);err:	return ERR_PTR(ret);}EXPORT_SYMBOL_GPL(regmap_init); /** * regmap_exit(): Free a previously allocated register map */void regmap_exit(struct regmap *map){	kfree(map->work_buf);	kfree(map);}EXPORT_SYMBOL_GPL(regmap_exit); static int _regmap_raw_write(struct regmap *map, unsigned int reg,			     const void *val, size_t val_len){	void *buf;	int ret = -ENOTSUPP;	size_t len; 	map->format.format_reg(map->work_buf, reg); 	/* Try to do a gather write if we can */	if (map->bus->gather_write)		ret = map->bus->gather_write(map->dev, map->work_buf,					     map->format.reg_bytes,					     val, val_len); 	/* Otherwise fall back on linearising by hand. */	if (ret == -ENOTSUPP) {		len = map->format.reg_bytes + val_len;		buf = kmalloc(len, GFP_KERNEL);		if (!buf)			return -ENOMEM; 		memcpy(buf, map->work_buf, map->format.reg_bytes);		memcpy(buf + map->format.reg_bytes, val, val_len);		ret = map->bus->write(map->dev, buf, len); 		kfree(buf);	} 	return ret;} static int _regmap_write(struct regmap *map, unsigned int reg,			 unsigned int val){	BUG_ON(!map->format.format_write && !map->format.format_val); 	if (map->format.format_write) {		map->format.format_write(map, reg, val); 		return map->bus->write(map->dev, map->work_buf,				       map->format.buf_size);	} else {		map->format.format_val(map->work_buf + map->format.reg_bytes,				       val);		return _regmap_raw_write(map, reg,					 map->work_buf + map->format.reg_bytes,					 map->format.val_bytes);	}} /** * regmap_write(): Write a value to a single register * * @map: Register map to write to * @reg: Register to write to * @val: Value to be written * * A value of zero will be returned on success, a negative errno will * be returned in error cases. */int regmap_write(struct regmap *map, unsigned int reg, unsigned int val){	int ret; 	mutex_lock(&map->lock); 	ret = _regmap_write(map, reg, val); 	mutex_unlock(&map->lock); 	return ret;}EXPORT_SYMBOL_GPL(regmap_write); /** * regmap_raw_write(): Write raw values to one or more registers * * @map: Register map to write to * @reg: Initial register to write to * @val: Block of data to be written, laid out for direct transmission to the *       device * @val_len: Length of data pointed to by val. * * This function is intended to be used for things like firmware * download where a large block of data needs to be transferred to the * device.  No formatting will be done on the data provided. * * A value of zero will be returned on success, a negative errno will * be returned in error cases. */int regmap_raw_write(struct regmap *map, unsigned int reg,		     const void *val, size_t val_len){	int ret; 	mutex_lock(&map->lock); 	ret = _regmap_raw_write(map, reg, val, val_len); 	mutex_unlock(&map->lock); 	return ret;}EXPORT_SYMBOL_GPL(regmap_raw_write); static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,			    unsigned int val_len){	u8 *u8 = map->work_buf;	int ret; 	map->format.format_reg(map->work_buf, reg); 	/*	 * Some buses flag reads by setting the high bits in the	 * register addresss; since it's always the high bits for all	 * current formats we can do this here rather than in	 * formatting.  This may break if we get interesting formats.	 */	if (map->bus->read_flag_mask)		u8[0] |= map->bus->read_flag_mask; 	ret = map->bus->read(map->dev, map->work_buf, map->format.reg_bytes,			     val, val_len);	if (ret != 0)		return ret; 	return 0;} static int _regmap_read(struct regmap *map, unsigned int reg,			unsigned int *val){	int ret; 	if (!map->format.parse_val)		return -EINVAL; 	ret = _regmap_raw_read(map, reg, map->work_buf, map->format.val_bytes);	if (ret == 0)		*val = map->format.parse_val(map->work_buf); 	return ret;} /** * regmap_read(): Read a value from a single register * * @map: Register map to write to * @reg: Register to be read from * @val: Pointer to store read value * * A value of zero will be returned on success, a negative errno will * be returned in error cases. */int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val){	int ret; 	mutex_lock(&map->lock); 	ret = _regmap_read(map, reg, val); 	mutex_unlock(&map->lock); 	return ret;}EXPORT_SYMBOL_GPL(regmap_read); /** * regmap_raw_read(): Read raw data from the device * * @map: Register map to write to * @reg: First register to be read from * @val: Pointer to store read value * @val_len: Size of data to read * * A value of zero will be returned on success, a negative errno will * be returned in error cases. */int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,		    size_t val_len){	int ret; 	mutex_lock(&map->lock); 	ret = _regmap_raw_read(map, reg, val, val_len); 	mutex_unlock(&map->lock); 	return ret;}EXPORT_SYMBOL_GPL(regmap_raw_read); /** * regmap_bulk_read(): Read multiple registers from the device * * @map: Register map to write to * @reg: First register to be read from * @val: Pointer to store read value, in native register size for device * @val_count: Number of registers to read * * A value of zero will be returned on success, a negative errno will * be returned in error cases. */int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,		     size_t val_count){	int ret, i;	size_t val_bytes = map->format.val_bytes; 	if (!map->format.parse_val)		return -EINVAL; 	ret = regmap_raw_read(map, reg, val, val_bytes * val_count);	if (ret != 0)		return ret; 	for (i = 0; i < val_count * val_bytes; i += val_bytes)		map->format.parse_val(val + i); 	return 0;}EXPORT_SYMBOL_GPL(regmap_bulk_read); /** * remap_update_bits: Perform a read/modify/write cycle on the register map * * @map: Register map to update * @reg: Register to update * @mask: Bitmask to change * @val: New value for bitmask * * Returns zero for success, a negative number on error. */int regmap_update_bits(struct regmap *map, unsigned int reg,		       unsigned int mask, unsigned int val){	int ret;	unsigned int tmp; 	mutex_lock(&map->lock); 	ret = _regmap_read(map, reg, &tmp);	if (ret != 0)		goto out; 	tmp &= ~mask;	tmp |= val & mask; 	ret = _regmap_write(map, reg, tmp); out:	mutex_unlock(&map->lock); 	return ret;}EXPORT_SYMBOL_GPL(regmap_update_bits);