Commit 04c50ccf authored by Mark Brown's avatar Mark Brown
Browse files

regmap: Only send a single buffer for async I/O if writing one register 



Extend the interface for async I/O by allowing the value buffer to be
omitted and sending the value as part of the register buffer, minimising
the number of separate hardware operations required.

Signed-off-by: default avatarMark Brown <broonie@linaro.org>
parent cd1b9dd0

drivers/base/regmap/regmap.c

+12 −7
Original line number Diff line number Diff line
@@ -1157,18 +1157,23 @@ int _regmap_raw_write(struct regmap *map, unsigned int reg, 
		/* 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);

		if (val == work_val)

			val = async->work_buf + map->format.pad_bytes +

				map->format.reg_bytes;



		spin_lock_irqsave(&map->async_lock, flags);

		list_add_tail(&async->list, &map->async_list);

		spin_unlock_irqrestore(&map->async_lock, flags);



		ret = map->bus->async_write(map->bus_context, async->work_buf,

		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",