regmap: add regmap_bulk_write() for register write

The bulk_write() supports the data transfer to multi
register which takes the data into cpu_endianness format
and does formatting of data to device format before
sending to device.
The transfer can be completed in single transfer or multiple
transfer based on data formatting.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 50 insertions, 0 deletions

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 74a6d4f8e3b..2366b6299f0 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -473,6 +473,56 @@ int regmap_raw_write(struct regmap *map, unsigned int reg,
 }
 EXPORT_SYMBOL_GPL(regmap_raw_write);
 
+/*
+ * 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 be 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;
+        void *wval;
+
+        if (!map->format.parse_val)
+                return -EINVAL;
+
+        mutex_lock(&map->lock);
+
+        /* No formatting is require if val_byte is 1 */
+        if (val_bytes == 1) {
+                wval = (void *)val;
+        } else {
+                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_val(wval + i);
+        }
+        ret = _regmap_raw_write(map, reg, wval, val_bytes * val_count);
+
+        if (val_bytes != 1)
+                kfree(wval);
+
+out:
+        mutex_unlock(&map->lock);
+        return ret;
+}
+EXPORT_SYMBOL_GPL(regmap_bulk_write);
+
 static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
                             unsigned int val_len)
 {