regmap: Converts group operation into single read write operations

Some devices does not support bulk read and write operations, for them
we have series of single write and read operations.

Signed-off-by: Anthony Olech <Anthony.Olech@diasemi.com>
Signed-off-by: Ashish Jangam <ashish.jangam@kpitcummins.com>
[Fixed coding style, don't check use_single_rw before assign --broonie ]
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

3 files changed, 44 insertions, 4 deletions

diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index d92e9b1cb83c..2eb719704885 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -91,6 +91,9 @@ struct regmap {
 
         struct reg_default *patch;
         int patch_regs;
+
+        /* if set, converts bulk rw to single rw */
+        bool use_single_rw;
 };
 
 struct regcache_ops {
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 8a25006b2a4d..0a05a706e141 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -247,6 +247,7 @@ 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->dev = dev;
         map->bus = bus;
         map->bus_context = bus_context;
@@ -686,7 +687,22 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
                 for (i = 0; i < val_count * val_bytes; i += val_bytes)
                         map->format.parse_val(wval + i);
         }
-        ret = _regmap_raw_write(map, reg, wval, val_bytes * val_count);
+        /*
+         * Some devices does not support bulk write, for
+         * them we have a series of single write operations.
+         */
+        if (map->use_single_rw) {
+                for (i = 0; i < val_count; i++) {
+                        ret = regmap_raw_write(map,
+                                                reg + (i * map->reg_stride),
+                                                val + (i * val_bytes),
+                                                val_bytes);
+                        if (ret != 0)
+                                return ret;
+                }
+        } else {
+                ret = _regmap_raw_write(map, reg, wval, val_bytes * val_count);
+        }
 
         if (val_bytes != 1)
                 kfree(wval);
@@ -855,9 +871,25 @@ int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
                 return -EINVAL;
 
         if (vol || map->cache_type == REGCACHE_NONE) {
-                ret = regmap_raw_read(map, reg, val, val_bytes * val_count);
-                if (ret != 0)
-                        return ret;
+                /*
+                 * 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_val(val + i);
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 0258bcd6258d..ae797b142aa8 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -76,6 +76,9 @@ struct reg_default {
  * @write_flag_mask: Mask to be set in the top byte of the register when doing
  *                   a write. If both read_flag_mask and write_flag_mask are
  *                   empty the regmap_bus default masks are used.
+ * @use_single_rw: If set, converts the bulk read and write operations into
+ *                  a series of single read and write operations. This is useful
+ *                  for device that does not support bulk read and write.
  *
  * @cache_type: The actual cache type.
  * @reg_defaults_raw: Power on reset values for registers (for use with
@@ -104,6 +107,8 @@ struct regmap_config {
 
         u8 read_flag_mask;
         u8 write_flag_mask;
+
+        bool use_single_rw;
 };
 
 typedef int (*regmap_hw_write)(void *context, const void *data,