regmap: Split use_single_rw internally into use_single_read/write

use_single_rw currently reflects the capabilities of the connected
device. The capabilities of the bus are currently missing for this
variable.

As there are read only and write only buses we need seperate values for
use_single_rw to also reflect tha capabilities of the bus.

This patch splits use_single_rw into use_single_read and
use_single_write. The initialization is changed to check the
configuration for use_single_rw and to check the capabilities of the
used bus.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/base/regmap/internal.h

@@ -139,8 +139,10 @@ struct regmap {
 	struct reg_default *patch;
 	int patch_regs;
 
-	/* if set, converts bulk rw to single rw */
-	bool use_single_rw;
+	/* if set, converts bulk read to single read */
+	bool use_single_read;
+	/* if set, converts bulk read to single read */
+	bool use_single_write;
 	/* if set, the device supports multi write mode */
 	bool can_multi_write;
 

drivers/base/regmap/regcache.c

@@ -729,7 +729,7 @@ int regcache_sync_block(struct regmap *map, void *block,
 			unsigned int block_base, unsigned int start,
 			unsigned int end)
 {
-	if (regmap_can_raw_write(map) && !map->use_single_rw)
+	if (regmap_can_raw_write(map) && !map->use_single_write)
 		return regcache_sync_block_raw(map, block, cache_present,
 					       block_base, start, end);
 	else

drivers/base/regmap/regmap-irq.c

@@ -209,7 +209,7 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
 	 * Read in the statuses, using a single bulk read if possible
 	 * in order to reduce the I/O overheads.
 	 */
-	if (!map->use_single_rw && map->reg_stride == 1 &&
+	if (!map->use_single_read && map->reg_stride == 1 &&
 	    data->irq_reg_stride == 1) {
 		u8 *buf8 = data->status_reg_buf;
 		u16 *buf16 = data->status_reg_buf;
@@ -398,7 +398,7 @@ int regmap_add_irq_chip(struct regmap *map, int irq, int irq_flags,
 	else
 		d->irq_reg_stride = 1;
 
-	if (!map->use_single_rw && map->reg_stride == 1 &&
+	if (!map->use_single_read && map->reg_stride == 1 &&
 	    d->irq_reg_stride == 1) {
 		d->status_reg_buf = kmalloc(map->format.val_bytes *
 					    chip->num_regs, GFP_KERNEL);

drivers/base/regmap/regmap.c

@@ -576,7 +576,8 @@ struct regmap *regmap_init(struct device *dev,
 		map->reg_stride = config->reg_stride;
 	else
 		map->reg_stride = 1;
-	map->use_single_rw = config->use_single_rw;
+	map->use_single_read = config->use_single_rw || !bus || !bus->read;
+	map->use_single_write = config->use_single_rw || !bus || !bus->write;
 	map->can_multi_write = config->can_multi_write;
 	map->dev = dev;
 	map->bus = bus;
@@ -766,7 +767,7 @@ struct regmap *regmap_init(struct device *dev,
 		if ((reg_endian != REGMAP_ENDIAN_BIG) ||
 		    (val_endian != REGMAP_ENDIAN_BIG))
 			goto err_map;
-		map->use_single_rw = true;
+		map->use_single_write = true;
 	}
 
 	if (!map->format.format_write &&
@@ -1720,7 +1721,7 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
 		}
 out:
 		map->unlock(map->lock_arg);
-	} else if (map->use_single_rw) {
+	} else if (map->use_single_write) {
 		map->lock(map->lock_arg);
 		for (i = 0; i < val_count; i++) {
 			ret = _regmap_raw_write(map,
@@ -2312,7 +2313,7 @@ int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
 		 * Some devices does not support bulk read, for
 		 * them we have a series of single read operations.
 		 */
-		if (map->use_single_rw) {
+		if (map->use_single_read) {
 			for (i = 0; i < val_count; i++) {
 				ret = regmap_raw_read(map,
 						reg + (i * map->reg_stride),