regmap.c

		struct regmap_range_node *range;

		/* Coalesce all the writes between a page break or a delay
		 * in a sequence
		 */
		range = _regmap_range_lookup(map, reg);
		if (range || regs[i].delay_us) {
			size_t len = sizeof(struct reg_sequence)*num_regs;
			struct reg_sequence *base = kmemdup(regs, len,
							   GFP_KERNEL);
			if (!base)
				return -ENOMEM;
			ret = _regmap_range_multi_paged_reg_write(map, base,
								  num_regs);
			kfree(base);

			return ret;
		}
	}
	return _regmap_raw_multi_reg_write(map, regs, num_regs);
}

/*
 * regmap_multi_reg_write(): Write multiple registers to the device
 *
 * where the set of register,value pairs are supplied in any order,
 * possibly not all in a single range.
 *
 * @map: Register map to write to
 * @regs: Array of structures containing register,value to be written
 * @num_regs: Number of registers to write
 *
 * The 'normal' block write mode will send ultimately send data on the
 * target bus as R,V1,V2,V3,..,Vn where successively higer registers are
 * addressed. However, this alternative block multi write mode will send
 * the data as R1,V1,R2,V2,..,Rn,Vn on the target bus. The target device
 * must of course support the 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, const struct reg_sequence *regs,
			   int num_regs)
{
	int ret;

	map->lock(map->lock_arg);

	ret = _regmap_multi_reg_write(map, regs, num_regs);

	map->unlock(map->lock_arg);

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_multi_reg_write);

/*
 * regmap_multi_reg_write_bypassed(): Write multiple registers to the
 *                                    device but not the cache
 *
 * 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_bypassed(struct regmap *map,
				    const struct reg_sequence *regs,
				    int num_regs)
{
	int ret;
	bool bypass;

	map->lock(map->lock_arg);

	bypass = map->cache_bypass;
	map->cache_bypass = true;

	ret = _regmap_multi_reg_write(map, regs, num_regs);

	map->cache_bypass = bypass;

	map->unlock(map->lock_arg);

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_multi_reg_write_bypassed);

/**
 * 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 address; 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, 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, reg, val_len / map->format.val_bytes);

	return ret;
}

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

	return map->bus->reg_read(map->bus_context, reg, val);
}

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);

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

		trace_regmap_reg_read(map, 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;
	if (val_count == 0)
		return -EINVAL;

	map->lock(map->lock_arg);

	if (regmap_volatile_range(map, reg, val_count) || map->cache_bypass ||
	    map->cache_type == REGCACHE_NONE) {
		if (!map->bus->read) {
			ret = -ENOTSUPP;
			goto out;
		}
		if (map->max_raw_read && map->max_raw_read < val_len) {
			ret = -E2BIG;
			goto out;
		}

		/* 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.
		 */
		size_t total_size = val_bytes * val_count;

		if (!map->use_single_read &&
		    (!map->max_raw_read || map->max_raw_read > total_size)) {
			ret = regmap_raw_read(map, reg, val,
					      val_bytes * val_count);
			if (ret != 0)
				return ret;
		} else {
			/*
			 * Some devices do not support bulk read or do not
			 * support large bulk reads, for them we have a series
			 * of read operations.
			 */
			int chunk_stride = map->reg_stride;
			size_t chunk_size = val_bytes;
			size_t chunk_count = val_count;

			if (!map->use_single_read) {
				chunk_size = map->max_raw_read;
				if (chunk_size % val_bytes)
					chunk_size -= chunk_size % val_bytes;
				chunk_count = total_size / chunk_size;
				chunk_stride *= chunk_size / val_bytes;
			}

			/* Read bytes that fit into a multiple of chunk_size */
			for (i = 0; i < chunk_count; i++) {
				ret = regmap_raw_read(map,
						      reg + (i * chunk_stride),
						      val + (i * chunk_size),
						      chunk_size);
				if (ret != 0)
					return ret;
			}

			/* Read remaining bytes */
			if (chunk_size * i < total_size) {
				ret = regmap_raw_read(map,
						      reg + (i * chunk_stride),
						      val + (i * chunk_size),
						      total_size - i * chunk_size);
				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;

			if (map->format.format_val) {
				map->format.format_val(val + (i * val_bytes), ival, 0);
			} else {
				/* Devices providing read and write
				 * operations can use the bulk I/O
				 * functions if they define a val_bytes,
				 * we assume that the values are native
				 * endian.
				 */
				u32 *u32 = val;
				u16 *u16 = val;
				u8 *u8 = val;

				switch (map->format.val_bytes) {
				case 4:
					u32[i] = ival;
					break;
				case 2:
					u16[i] = ival;
					break;
				case 1:
					u8[i] = ival;
					break;
				default:
					return -EINVAL;
				}
			}
		}
	}

	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, bool force_write)
{
	int ret;
	unsigned int tmp, orig;

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

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

	if (force_write || (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, false);
	map->unlock(map->lock_arg);

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_update_bits);

/**
 * regmap_write_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_write_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, true);
	map->unlock(map->lock_arg);

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_write_bits);

/**
 * regmap_update_bits_async: Perform a read/modify/write cycle on the register
 *                           map asynchronously
 *
 * @map: Register map to update
 * @reg: Register to update
 * @mask: Bitmask to change
 * @val: New value for bitmask
 *
 * With most buses the read must be done synchronously so this is most
 * useful for devices with a cache which do not need to interact with
 * the hardware to determine the current register value.
 *
 * Returns zero for success, a negative number on error.
 */
int regmap_update_bits_async(struct regmap *map, unsigned int reg,
			     unsigned int mask, unsigned int val)
{
	int ret;

	map->lock(map->lock_arg);

	map->async = true;

	ret = _regmap_update_bits(map, reg, mask, val, NULL, false);

	map->async = false;

	map->unlock(map->lock_arg);

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_update_bits_async);

/**
 * regmap_update_bits_check: Perform a read/modify/write cycle on the
 *                           register map and report if updated
 *
 * @map: Register map to update
 * @reg: Register to update
 * @mask: Bitmask to change
 * @val: New value for bitmask
 * @change: Boolean indicating if a write was done
 *
 * Returns zero for success, a negative number on error.
 */
int regmap_update_bits_check(struct regmap *map, unsigned int reg,
			     unsigned int mask, unsigned int val,
			     bool *change)
{
	int ret;

	map->lock(map->lock_arg);
	ret = _regmap_update_bits(map, reg, mask, val, change, false);
	map->unlock(map->lock_arg);
	return ret;
}
EXPORT_SYMBOL_GPL(regmap_update_bits_check);

/**
 * regmap_update_bits_check_async: Perform a read/modify/write cycle on the
 *                                 register map asynchronously and report if
 *                                 updated
 *
 * @map: Register map to update
 * @reg: Register to update
 * @mask: Bitmask to change
 * @val: New value for bitmask
 * @change: Boolean indicating if a write was done
 *
 * With most buses the read must be done synchronously so this is most
 * useful for devices with a cache which do not need to interact with
 * the hardware to determine the current register value.
 *
 * Returns zero for success, a negative number on error.
 */
int regmap_update_bits_check_async(struct regmap *map, unsigned int reg,
				   unsigned int mask, unsigned int val,
				   bool *change)
{
	int ret;

	map->lock(map->lock_arg);

	map->async = true;

	ret = _regmap_update_bits(map, reg, mask, val, change, false);

	map->async = false;

	map->unlock(map->lock_arg);

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_update_bits_check_async);

void regmap_async_complete_cb(struct regmap_async *async, int ret)
{
	struct regmap *map = async->map;
	bool wake;

	trace_regmap_async_io_complete(map);

	spin_lock(&map->async_lock);
	list_move(&async->list, &map->async_free);
	wake = list_empty(&map->async_list);

	if (ret != 0)
		map->async_ret = ret;

	spin_unlock(&map->async_lock);

	if (wake)
		wake_up(&map->async_waitq);
}
EXPORT_SYMBOL_GPL(regmap_async_complete_cb);

static int regmap_async_is_done(struct regmap *map)
{
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&map->async_lock, flags);
	ret = list_empty(&map->async_list);
	spin_unlock_irqrestore(&map->async_lock, flags);

	return ret;
}

/**
 * regmap_async_complete: Ensure all asynchronous I/O has completed.
 *
 * @map: Map to operate on.
 *
 * Blocks until any pending asynchronous I/O has completed.  Returns
 * an error code for any failed I/O operations.
 */
int regmap_async_complete(struct regmap *map)
{
	unsigned long flags;
	int ret;

	/* Nothing to do with no async support */
	if (!map->bus || !map->bus->async_write)
		return 0;

	trace_regmap_async_complete_start(map);

	wait_event(map->async_waitq, regmap_async_is_done(map));

	spin_lock_irqsave(&map->async_lock, flags);
	ret = map->async_ret;
	map->async_ret = 0;
	spin_unlock_irqrestore(&map->async_lock, flags);

	trace_regmap_async_complete_done(map);

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_async_complete);

/**
 * regmap_register_patch: Register and apply register updates to be applied
 *                        on device initialistion
 *
 * @map: Register map to apply updates to.
 * @regs: Values to update.
 * @num_regs: Number of entries in regs.
 *
 * Register a set of register updates to be applied to the device
 * whenever the device registers are synchronised with the cache and
 * apply them immediately.  Typically this is used to apply
 * corrections to be applied to the device defaults on startup, such
 * as the updates some vendors provide to undocumented registers.
 *
 * The caller must ensure that this function cannot be called
 * concurrently with either itself or regcache_sync().
 */
int regmap_register_patch(struct regmap *map, const struct reg_sequence *regs,
			  int num_regs)
{
	struct reg_sequence *p;
	int ret;
	bool bypass;

	if (WARN_ONCE(num_regs <= 0, "invalid registers number (%d)\n",
	    num_regs))
		return 0;

	p = krealloc(map->patch,
		     sizeof(struct reg_sequence) * (map->patch_regs + num_regs),
		     GFP_KERNEL);
	if (p) {
		memcpy(p + map->patch_regs, regs, num_regs * sizeof(*regs));
		map->patch = p;
		map->patch_regs += num_regs;
	} else {
		return -ENOMEM;
	}

	map->lock(map->lock_arg);

	bypass = map->cache_bypass;

	map->cache_bypass = true;
	map->async = true;

	ret = _regmap_multi_reg_write(map, regs, num_regs);

	map->async = false;
	map->cache_bypass = bypass;

	map->unlock(map->lock_arg);

	regmap_async_complete(map);

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_register_patch);

/*
 * regmap_get_val_bytes(): Report the size of a register value
 *
 * Report the size of a register value, mainly intended to for use by
 * generic infrastructure built on top of regmap.
 */
int regmap_get_val_bytes(struct regmap *map)
{
	if (map->format.format_write)
		return -EINVAL;

	return map->format.val_bytes;
}
EXPORT_SYMBOL_GPL(regmap_get_val_bytes);

/**
 * regmap_get_max_register(): Report the max register value
 *
 * Report the max register value, mainly intended to for use by
 * generic infrastructure built on top of regmap.
 */
int regmap_get_max_register(struct regmap *map)
{
	return map->max_register ? map->max_register : -EINVAL;
}
EXPORT_SYMBOL_GPL(regmap_get_max_register);

/**
 * regmap_get_reg_stride(): Report the register address stride
 *
 * Report the register address stride, mainly intended to for use by
 * generic infrastructure built on top of regmap.
 */
int regmap_get_reg_stride(struct regmap *map)
{
	return map->reg_stride;
}
EXPORT_SYMBOL_GPL(regmap_get_reg_stride);

int regmap_parse_val(struct regmap *map, const void *buf,
			unsigned int *val)
{
	if (!map->format.parse_val)
		return -EINVAL;

	*val = map->format.parse_val(buf);

	return 0;
}
EXPORT_SYMBOL_GPL(regmap_parse_val);

static int __init regmap_initcall(void)
{
	regmap_debugfs_initcall();

	return 0;
}
postcore_initcall(regmap_initcall);