ASoC: soc-cache: Introduce raw bulk write support

As it has become more common to have to write firmware or similar
large chunks of data to the hardware, add a function to perform
raw bulk writes that bypass the cache.  This only handles volatile
registers as we should avoid getting out of sync with the actual
cache.

Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

3 files changed, 49 insertions, 0 deletions

diff --git a/include/sound/soc.h b/include/sound/soc.h
index bfa4836ea107..2f2a51fe78e9 100644
--- a/include/sound/soc.h
+++ b/include/sound/soc.h
@@ -543,6 +543,7 @@ struct snd_soc_codec {
         unsigned int (*hw_read)(struct snd_soc_codec *, unsigned int);
         unsigned int (*read)(struct snd_soc_codec *, unsigned int);
         int (*write)(struct snd_soc_codec *, unsigned int, unsigned int);
+        int (*bulk_write_raw)(struct snd_soc_codec *, unsigned int, const void *, size_t);
         void *reg_cache;
         const void *reg_def_copy;
         const struct snd_soc_cache_ops *cache_ops;
@@ -814,6 +815,8 @@ struct soc_enum {
 unsigned int snd_soc_read(struct snd_soc_codec *codec, unsigned int reg);
 unsigned int snd_soc_write(struct snd_soc_codec *codec,
                            unsigned int reg, unsigned int val);
+unsigned int snd_soc_bulk_write_raw(struct snd_soc_codec *codec,
+                                    unsigned int reg, const void *data, size_t len);
 
 /* device driver data */
 
diff --git a/sound/soc/soc-cache.c b/sound/soc/soc-cache.c
index 9f6737413a6e..8bcd4e1cee91 100644
--- a/sound/soc/soc-cache.c
+++ b/sound/soc/soc-cache.c
@@ -625,6 +625,44 @@ static int snd_soc_16_16_spi_write(void *control_data, const char *data,
 #define snd_soc_16_16_spi_write NULL
 #endif
 
+/* Primitive bulk write support for soc-cache.  The data pointed to by `data' needs
+ * to already be in the form the hardware expects including any leading register specific
+ * data.  Any data written through this function will not go through the cache as it
+ * only handles writing to volatile or out of bounds registers.
+ */
+static int snd_soc_hw_bulk_write_raw(struct snd_soc_codec *codec, unsigned int reg,
+                                     const void *data, size_t len)
+{
+        int ret;
+
+        /* Ensure that the base register is volatile.  Subsequently
+         * any other register that is touched by this routine should be
+         * volatile as well to ensure that we don't get out of sync with
+         * the cache.
+         */
+        if (!snd_soc_codec_volatile_register(codec, reg)
+            && reg < codec->driver->reg_cache_size)
+                return -EINVAL;
+
+        switch (codec->control_type) {
+        case SND_SOC_I2C:
+                ret = i2c_master_send(codec->control_data, data, len);
+                break;
+        case SND_SOC_SPI:
+                ret = do_spi_write(codec->control_data, data, len);
+                break;
+        default:
+                BUG();
+        }
+
+        if (ret == len)
+                return 0;
+        if (ret < 0)
+                return ret;
+        else
+                return -EIO;
+}
+
 static struct {
         int addr_bits;
         int data_bits;
@@ -708,6 +746,7 @@ int snd_soc_codec_set_cache_io(struct snd_soc_codec *codec,
 
         codec->write = io_types[i].write;
         codec->read = io_types[i].read;
+        codec->bulk_write_raw = snd_soc_hw_bulk_write_raw;
 
         switch (control) {
         case SND_SOC_CUSTOM:
diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 4dda58926bc5..636328e868e8 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -2228,6 +2228,13 @@ unsigned int snd_soc_write(struct snd_soc_codec *codec,
 }
 EXPORT_SYMBOL_GPL(snd_soc_write);
 
+unsigned int snd_soc_bulk_write_raw(struct snd_soc_codec *codec,
+                                    unsigned int reg, const void *data, size_t len)
+{
+        return codec->bulk_write_raw(codec, reg, data, len);
+}
+EXPORT_SYMBOL_GPL(snd_soc_bulk_write_raw);
+
 /**
  * snd_soc_update_bits - update codec register bits
  * @codec: audio codec