regmap.c

	void *orig_work_buf;
	unsigned int win_offset;
	unsigned int win_page;
	bool page_chg;
	int ret;

	win_offset = (*reg - range->range_min) % range->window_len;
	win_page = (*reg - range->range_min) / range->window_len;

	if (val_num > 1) {
		/* Bulk write shouldn't cross range boundary */
		if (*reg + val_num - 1 > range->range_max)
			return -EINVAL;

		/* ... or single page boundary */
		if (val_num > range->window_len - win_offset)
			return -EINVAL;
	}

	/* It is possible to have selector register inside data window.
	   In that case, selector register is located on every page and
	   it needs no page switching, when accessed alone. */
	if (val_num > 1 ||
	    range->window_start + win_offset != range->selector_reg) {
		/* Use separate work_buf during page switching */
		orig_work_buf = map->work_buf;
		map->work_buf = map->selector_work_buf;

		ret = _regmap_update_bits(map, range->selector_reg,
					  range->selector_mask,
					  win_page << range->selector_shift,
					  &page_chg);

		map->work_buf = orig_work_buf;

		if (ret != 0)
			return ret;
	}

	*reg = range->window_start + win_offset;

	return 0;
}

int _regmap_raw_write(struct regmap *map, unsigned int reg,
		      const void *val, size_t val_len)
{
	struct regmap_range_node *range;
	unsigned long flags;
	u8 *u8 = map->work_buf;
	void *work_val = map->work_buf + map->format.reg_bytes +
		map->format.pad_bytes;
	void *buf;
	int ret = -ENOTSUPP;
	size_t len;
	int i;

	WARN_ON(!map->bus);

	/* Check for unwritable registers before we start */
	if (map->writeable_reg)
		for (i = 0; i < val_len / map->format.val_bytes; i++)
			if (!map->writeable_reg(map->dev,
						reg + (i * map->reg_stride)))
				return -EINVAL;

	if (!map->cache_bypass && map->format.parse_val) {
		unsigned int ival;
		int val_bytes = map->format.val_bytes;
		for (i = 0; i < val_len / val_bytes; i++) {
			ival = map->format.parse_val(val + (i * val_bytes));
			ret = regcache_write(map, reg + (i * map->reg_stride),
					     ival);
			if (ret) {
				dev_err(map->dev,
					"Error in caching of register: %x ret: %d\n",
					reg + i, ret);
				return ret;
			}
		}
		if (map->cache_only) {
			map->cache_dirty = true;
			return 0;
		}
	}

	range = _regmap_range_lookup(map, reg);
	if (range) {
		int val_num = val_len / map->format.val_bytes;
		int win_offset = (reg - range->range_min) % range->window_len;
		int win_residue = range->window_len - win_offset;

		/* If the write goes beyond the end of the window split it */
		while (val_num > win_residue) {
			dev_dbg(map->dev, "Writing window %d/%zu\n",
				win_residue, val_len / map->format.val_bytes);
			ret = _regmap_raw_write(map, reg, val, win_residue *
						map->format.val_bytes);
			if (ret != 0)
				return ret;

			reg += win_residue;
			val_num -= win_residue;
			val += win_residue * map->format.val_bytes;
			val_len -= win_residue * map->format.val_bytes;

			win_offset = (reg - range->range_min) %
				range->window_len;
			win_residue = range->window_len - win_offset;
		}

		ret = _regmap_select_page(map, &reg, range, val_num);
		if (ret != 0)
			return ret;
	}

	map->format.format_reg(map->work_buf, reg, map->reg_shift);

	u8[0] |= map->write_flag_mask;

	/*
	 * Essentially all I/O mechanisms will be faster with a single
	 * buffer to write.  Since register syncs often generate raw
	 * writes of single registers optimise that case.
	 */
	if (val != work_val && val_len == map->format.val_bytes) {
		memcpy(work_val, val, map->format.val_bytes);
		val = work_val;
	}

	if (map->async && map->bus->async_write) {
		struct regmap_async *async;

		trace_regmap_async_write_start(map->dev, reg, val_len);

		spin_lock_irqsave(&map->async_lock, flags);
		async = list_first_entry_or_null(&map->async_free,
						 struct regmap_async,
						 list);
		if (async)
			list_del(&async->list);
		spin_unlock_irqrestore(&map->async_lock, flags);

		if (!async) {
			async = map->bus->async_alloc();
			if (!async)
				return -ENOMEM;

			async->work_buf = kzalloc(map->format.buf_size,
						  GFP_KERNEL | GFP_DMA);
			if (!async->work_buf) {
				kfree(async);
				return -ENOMEM;
			}
		}

		async->map = map;

		/* If the caller supplied the value we can use it safely. */
		memcpy(async->work_buf, map->work_buf, map->format.pad_bytes +
		       map->format.reg_bytes + map->format.val_bytes);

		spin_lock_irqsave(&map->async_lock, flags);
		list_add_tail(&async->list, &map->async_list);
		spin_unlock_irqrestore(&map->async_lock, flags);

		if (val != work_val)
			ret = map->bus->async_write(map->bus_context,
						    async->work_buf,
						    map->format.reg_bytes +
						    map->format.pad_bytes,
						    val, val_len, async);
		else
			ret = map->bus->async_write(map->bus_context,
						    async->work_buf,
						    map->format.reg_bytes +
						    map->format.pad_bytes +
						    val_len, NULL, 0, async);

		if (ret != 0) {
			dev_err(map->dev, "Failed to schedule write: %d\n",
				ret);

			spin_lock_irqsave(&map->async_lock, flags);
			list_move(&async->list, &map->async_free);
			spin_unlock_irqrestore(&map->async_lock, flags);
		}

		return ret;
	}

	trace_regmap_hw_write_start(map->dev, reg,
				    val_len / map->format.val_bytes);

	/* If we're doing a single register write we can probably just
	 * send the work_buf directly, otherwise try to do a gather
	 * write.
	 */
	if (val == work_val)
		ret = map->bus->write(map->bus_context, map->work_buf,
				      map->format.reg_bytes +
				      map->format.pad_bytes +
				      val_len);
	else if (map->bus->gather_write)
		ret = map->bus->gather_write(map->bus_context, map->work_buf,
					     map->format.reg_bytes +
					     map->format.pad_bytes,
					     val, val_len);

	/* If that didn't work fall back on linearising by hand. */
	if (ret == -ENOTSUPP) {
		len = map->format.reg_bytes + map->format.pad_bytes + val_len;
		buf = kzalloc(len, GFP_KERNEL);
		if (!buf)
			return -ENOMEM;

		memcpy(buf, map->work_buf, map->format.reg_bytes);
		memcpy(buf + map->format.reg_bytes + map->format.pad_bytes,
		       val, val_len);
		ret = map->bus->write(map->bus_context, buf, len);

		kfree(buf);
	}

	trace_regmap_hw_write_done(map->dev, reg,
				   val_len / map->format.val_bytes);

	return ret;
}

/**
 * regmap_can_raw_write - Test if regmap_raw_write() is supported
 *
 * @map: Map to check.
 */
bool regmap_can_raw_write(struct regmap *map)
{
	return map->bus && map->format.format_val && map->format.format_reg;
}
EXPORT_SYMBOL_GPL(regmap_can_raw_write);

static int _regmap_bus_formatted_write(void *context, unsigned int reg,
				       unsigned int val)
{
	int ret;
	struct regmap_range_node *range;
	struct regmap *map = context;

	WARN_ON(!map->bus || !map->format.format_write);

	range = _regmap_range_lookup(map, reg);
	if (range) {
		ret = _regmap_select_page(map, &reg, range, 1);
		if (ret != 0)
			return ret;
	}

	map->format.format_write(map, reg, val);

	trace_regmap_hw_write_start(map->dev, reg, 1);

	ret = map->bus->write(map->bus_context, map->work_buf,
			      map->format.buf_size);

	trace_regmap_hw_write_done(map->dev, reg, 1);

	return ret;
}

static int _regmap_bus_raw_write(void *context, unsigned int reg,
				 unsigned int val)
{
	struct regmap *map = context;

	WARN_ON(!map->bus || !map->format.format_val);

	map->format.format_val(map->work_buf + map->format.reg_bytes
			       + map->format.pad_bytes, val, 0);
	return _regmap_raw_write(map, reg,
				 map->work_buf +
				 map->format.reg_bytes +
				 map->format.pad_bytes,
				 map->format.val_bytes);
}

static inline void *_regmap_map_get_context(struct regmap *map)
{
	return (map->bus) ? map : map->bus_context;
}

int _regmap_write(struct regmap *map, unsigned int reg,
		  unsigned int val)
{
	int ret;
	void *context = _regmap_map_get_context(map);

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

	if (!map->cache_bypass && !map->defer_caching) {
		ret = regcache_write(map, reg, val);
		if (ret != 0)
			return ret;
		if (map->cache_only) {
			map->cache_dirty = true;
			return 0;
		}
	}

#ifdef LOG_DEVICE
	if (strcmp(dev_name(map->dev), LOG_DEVICE) == 0)
		dev_info(map->dev, "%x <= %x\n", reg, val);
#endif

	trace_regmap_reg_write(map->dev, reg, val);

	return map->reg_write(context, reg, val);
}

/**
 * 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;

	if (reg % map->reg_stride)
		return -EINVAL;

	map->lock(map->lock_arg);

	ret = _regmap_write(map, reg, val);

	map->unlock(map->lock_arg);

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_write);

/**
 * regmap_write_async(): Write a value to a single register asynchronously
 *
 * @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_async(struct regmap *map, unsigned int reg, unsigned int val)
{
	int ret;

	if (reg % map->reg_stride)
		return -EINVAL;

	map->lock(map->lock_arg);

	map->async = true;

	ret = _regmap_write(map, reg, val);

	map->async = false;

	map->unlock(map->lock_arg);

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_write_async);

/**
 * 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;

	if (!regmap_can_raw_write(map))
		return -EINVAL;
	if (val_len % map->format.val_bytes)
		return -EINVAL;

	map->lock(map->lock_arg);

	ret = _regmap_raw_write(map, reg, val, val_len);

	map->unlock(map->lock_arg);

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_raw_write);

/**
 * regmap_field_write(): Write a value to a single register field
 *
 * @field: Register field 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_field_write(struct regmap_field *field, unsigned int val)
{
	return regmap_update_bits(field->regmap, field->reg,
				field->mask, val << field->shift);
}
EXPORT_SYMBOL_GPL(regmap_field_write);

/**
 * regmap_field_update_bits():	Perform a read/modify/write cycle
 *                              on the register field
 *
 * @field: Register field to write to
 * @mask: Bitmask to change
 * @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_field_update_bits(struct regmap_field *field, unsigned int mask, unsigned int val)
{
	mask = (mask << field->shift) & field->mask;

	return regmap_update_bits(field->regmap, field->reg,
				  mask, val << field->shift);
}
EXPORT_SYMBOL_GPL(regmap_field_update_bits);

/**
 * regmap_fields_write(): Write a value to a single register field with port ID
 *
 * @field: Register field to write to
 * @id: port ID
 * @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_fields_write(struct regmap_field *field, unsigned int id,
			unsigned int val)
{
	if (id >= field->id_size)
		return -EINVAL;

	return regmap_update_bits(field->regmap,
				  field->reg + (field->id_offset * id),
				  field->mask, val << field->shift);
}
EXPORT_SYMBOL_GPL(regmap_fields_write);

/**
 * regmap_fields_update_bits():	Perform a read/modify/write cycle
 *                              on the register field
 *
 * @field: Register field to write to
 * @id: port ID
 * @mask: Bitmask to change
 * @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_fields_update_bits(struct regmap_field *field,  unsigned int id,
			      unsigned int mask, unsigned int val)
{
	if (id >= field->id_size)
		return -EINVAL;

	mask = (mask << field->shift) & field->mask;

	return regmap_update_bits(field->regmap,
				  field->reg + (field->id_offset * id),
				  mask, val << field->shift);
}
EXPORT_SYMBOL_GPL(regmap_fields_update_bits);

/*
 * regmap_bulk_write(): Write multiple registers to the device
 *
 * @map: Register map to write to
 * @reg: First register to be write from
 * @val: Block of data to be written, in native register size for device
 * @val_count: Number of registers to write
 *
 * This function is intended to be used for writing a large block of
 * data to the device either in single transfer or multiple transfer.
 *
 * A value of zero will be returned on success, a negative errno will
 * be returned in error cases.
 */
int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
		     size_t val_count)
{
	int ret = 0, i;
	size_t val_bytes = map->format.val_bytes;

	if (map->bus && !map->format.parse_inplace)
		return -EINVAL;
	if (reg % map->reg_stride)
		return -EINVAL;

	map->lock(map->lock_arg);
	/*
	 * Some devices don't support bulk write, for
	 * them we have a series of single write operations.
	 */
	if (!map->bus || map->use_single_rw) {
		for (i = 0; i < val_count; i++) {
			unsigned int ival;

			switch (val_bytes) {
			case 1:
				ival = *(u8 *)(val + (i * val_bytes));
				break;
			case 2:
				ival = *(u16 *)(val + (i * val_bytes));
				break;
			case 4:
				ival = *(u32 *)(val + (i * val_bytes));
				break;
#ifdef CONFIG_64BIT
			case 8:
				ival = *(u64 *)(val + (i * val_bytes));
				break;
#endif
			default:
				ret = -EINVAL;
				goto out;
			}

			ret = _regmap_write(map, reg + (i * map->reg_stride),
					ival);
			if (ret != 0)
				goto out;
		}
	} else {
		void *wval;

		wval = kmemdup(val, val_count * val_bytes, GFP_KERNEL);
		if (!wval) {
			ret = -ENOMEM;
			dev_err(map->dev, "Error in memory allocation\n");
			goto out;
		}
		for (i = 0; i < val_count * val_bytes; i += val_bytes)
			map->format.parse_inplace(wval + i);

		ret = _regmap_raw_write(map, reg, wval, val_bytes * val_count);

		kfree(wval);
	}
out:
	map->unlock(map->lock_arg);
	return ret;
}
EXPORT_SYMBOL_GPL(regmap_bulk_write);

/*
 * regmap_multi_reg_write(): Write multiple registers to the device
 *
 * where the set of register are supplied in any order
 *
 * @map: Register map to write to
 * @regs: Array of structures containing register,value to be written
 * @num_regs: Number of registers to write
 *
 * This function is intended to be used for writing a large block of data
 * atomically to the device in single transfer for those I2C client devices
 * that implement this alternative block write mode.
 *
 * A value of zero will be returned on success, a negative errno will
 * be returned in error cases.
 */
int regmap_multi_reg_write(struct regmap *map, struct reg_default *regs,
				int num_regs)
{
	int ret = 0, i;

	for (i = 0; i < num_regs; i++) {
		int reg = regs[i].reg;
		if (reg % map->reg_stride)
			return -EINVAL;
	}

	map->lock(map->lock_arg);

	for (i = 0; i < num_regs; i++) {
		ret = _regmap_write(map, regs[i].reg, regs[i].def);
		if (ret != 0)
			goto out;
	}
out:
	map->unlock(map->lock_arg);

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_multi_reg_write);

/**
 * regmap_raw_write_async(): Write raw values to one or more registers
 *                           asynchronously
 *
 * @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.  Must be valid until regmap_async_complete() is called.
 * @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.
 *
 * If supported by the underlying bus the write will be scheduled
 * asynchronously, helping maximise I/O speed on higher speed buses
 * like SPI.  regmap_async_complete() can be called to ensure that all
 * asynchrnous writes have been completed.
 *
 * A value of zero will be returned on success, a negative errno will
 * be returned in error cases.
 */
int regmap_raw_write_async(struct regmap *map, unsigned int reg,
			   const void *val, size_t val_len)
{
	int ret;

	if (val_len % map->format.val_bytes)
		return -EINVAL;
	if (reg % map->reg_stride)
		return -EINVAL;

	map->lock(map->lock_arg);

	map->async = true;

	ret = _regmap_raw_write(map, reg, val, val_len);

	map->async = false;

	map->unlock(map->lock_arg);

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_raw_write_async);

static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
			    unsigned int val_len)
{
	struct regmap_range_node *range;
	u8 *u8 = map->work_buf;
	int ret;

	WARN_ON(!map->bus);

	range = _regmap_range_lookup(map, reg);
	if (range) {
		ret = _regmap_select_page(map, &reg, range,
					  val_len / map->format.val_bytes);
		if (ret != 0)
			return ret;
	}

	map->format.format_reg(map->work_buf, reg, map->reg_shift);

	/*
	 * Some buses or devices 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.
	 */
	u8[0] |= map->read_flag_mask;

	trace_regmap_hw_read_start(map->dev, reg,
				   val_len / map->format.val_bytes);

	ret = map->bus->read(map->bus_context, map->work_buf,
			     map->format.reg_bytes + map->format.pad_bytes,
			     val, val_len);

	trace_regmap_hw_read_done(map->dev, reg,
				  val_len / map->format.val_bytes);

	return ret;
}

static int _regmap_bus_read(void *context, unsigned int reg,
			    unsigned int *val)
{
	int ret;
	struct regmap *map = context;

	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;
}

static int _regmap_read(struct regmap *map, unsigned int reg,
			unsigned int *val)
{
	int ret;
	void *context = _regmap_map_get_context(map);

	WARN_ON(!map->reg_read);

	if (!map->cache_bypass) {
		ret = regcache_read(map, reg, val);
		if (ret == 0)
			return 0;
	}

	if (map->cache_only)
		return -EBUSY;

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

	ret = map->reg_read(context, reg, val);
	if (ret == 0) {
#ifdef LOG_DEVICE
		if (strcmp(dev_name(map->dev), LOG_DEVICE) == 0)
			dev_info(map->dev, "%x => %x\n", reg, *val);
#endif

		trace_regmap_reg_read(map->dev, reg, *val);

		if (!map->cache_bypass)
			regcache_write(map, reg, *val);
	}

	return ret;
}

/**
 * regmap_read(): Read a value from a single register
 *
 * @map: Register map to read from
 * @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;

	if (reg % map->reg_stride)
		return -EINVAL;

	map->lock(map->lock_arg);

	ret = _regmap_read(map, reg, val);

	map->unlock(map->lock_arg);

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_read);

/**
 * regmap_raw_read(): Read raw data from the device
 *
 * @map: Register map to read from
 * @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)
{
	size_t val_bytes = map->format.val_bytes;
	size_t val_count = val_len / val_bytes;
	unsigned int v;
	int ret, i;

	if (!map->bus)
		return -EINVAL;
	if (val_len % map->format.val_bytes)
		return -EINVAL;
	if (reg % map->reg_stride)
		return -EINVAL;

	map->lock(map->lock_arg);

	if (regmap_volatile_range(map, reg, val_count) || map->cache_bypass ||
	    map->cache_type == REGCACHE_NONE) {
		/* Physical block read if there's no cache involved */
		ret = _regmap_raw_read(map, reg, val, val_len);

	} else {
		/* Otherwise go word by word for the cache; should be low
		 * cost as we expect to hit the cache.
		 */
		for (i = 0; i < val_count; i++) {
			ret = _regmap_read(map, reg + (i * map->reg_stride),
					   &v);
			if (ret != 0)
				goto out;

			map->format.format_val(val + (i * val_bytes), v, 0);
		}
	}

 out:
	map->unlock(map->lock_arg);

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_raw_read);

/**
 * regmap_field_read(): Read a value to a single register field
 *
 * @field: Register field to 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_field_read(struct regmap_field *field, unsigned int *val)
{
	int ret;
	unsigned int reg_val;
	ret = regmap_read(field->regmap, field->reg, &reg_val);
	if (ret != 0)
		return ret;

	reg_val &= field->mask;
	reg_val >>= field->shift;
	*val = reg_val;

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_field_read);

/**
 * regmap_fields_read(): Read a value to a single register field with port ID
 *
 * @field: Register field to read from
 * @id: port ID
 * @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_fields_read(struct regmap_field *field, unsigned int id,
		       unsigned int *val)
{
	int ret;
	unsigned int reg_val;

	if (id >= field->id_size)
		return -EINVAL;

	ret = regmap_read(field->regmap,
			  field->reg + (field->id_offset * id),
			  &reg_val);
	if (ret != 0)
		return ret;

	reg_val &= field->mask;
	reg_val >>= field->shift;
	*val = reg_val;

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_fields_read);

/**
 * regmap_bulk_read(): Read multiple registers from the device
 *
 * @map: Register map to read from
 * @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;
	bool vol = regmap_volatile_range(map, reg, val_count);

	if (reg % map->reg_stride)
		return -EINVAL;

	if (map->bus && map->format.parse_inplace && (vol || map->cache_type == REGCACHE_NONE)) {
		/*
		 * Some devices does not support bulk read, for
		 * them we have a series of single read operations.
		 */
		if (map->use_single_rw) {
			for (i = 0; i < val_count; i++) {
				ret = regmap_raw_read(map,
						reg + (i * map->reg_stride),
						val + (i * val_bytes),
						val_bytes);
				if (ret != 0)
					return ret;
			}
		} else {
			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_inplace(val + i);
	} else {
		for (i = 0; i < val_count; i++) {
			unsigned int ival;
			ret = regmap_read(map, reg + (i * map->reg_stride),
					  &ival);
			if (ret != 0)
				return ret;
			memcpy(val + (i * val_bytes), &ival, val_bytes);
		}
	}

	return 0;
}
EXPORT_SYMBOL_GPL(regmap_bulk_read);

static int _regmap_update_bits(struct regmap *map, unsigned int reg,
			       unsigned int mask, unsigned int val,
			       bool *change)
{
	int ret;
	unsigned int tmp, orig;

	ret = _regmap_read(map, reg, &orig);
	if (ret != 0)
		return ret;

	tmp = orig & ~mask;
	tmp |= val & mask;

	if (tmp != orig) {
		ret = _regmap_write(map, reg, tmp);
		if (change)
			*change = true;
	} else {
		if (change)
			*change = false;
	}

	return ret;
}

/**
 * regmap_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;

	map->lock(map->lock_arg);
	ret = _regmap_update_bits(map, reg, mask, val, NULL);
	map->unlock(map->lock_arg);