ASoC: Begin to factor out register cache I/O functions

A lot of CODECs share the same register data formats and therefore
replicate the code to manage access to and caching of the register
map. In order to reduce code duplication centralised versions of
this code will be introduced with drivers able to configure the use
of the common code by calling the new snd_soc_codec_set_cache_io()
API call during startup.

As an initial user the 7 bit address/9 bit data format used by many
Wolfson devices is supported for write only CODECs and the drivers
with straightforward register cache implementations are converted to
use it.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 22 insertions, 56 deletions

diff --git a/sound/soc/codecs/wm8728.c b/sound/soc/codecs/wm8728.c
index e7ff2121ede9..66da44b08d35 100644
--- a/sound/soc/codecs/wm8728.c
+++ b/sound/soc/codecs/wm8728.c
@@ -43,45 +43,6 @@ static const u16 wm8728_reg_defaults[] = {
         0x100,
 };
 
-static inline unsigned int wm8728_read_reg_cache(struct snd_soc_codec *codec,
-        unsigned int reg)
-{
-        u16 *cache = codec->reg_cache;
-        BUG_ON(reg >= ARRAY_SIZE(wm8728_reg_defaults));
-        return cache[reg];
-}
-
-static inline void wm8728_write_reg_cache(struct snd_soc_codec *codec,
-        u16 reg, unsigned int value)
-{
-        u16 *cache = codec->reg_cache;
-        BUG_ON(reg >= ARRAY_SIZE(wm8728_reg_defaults));
-        cache[reg] = value;
-}
-
-/*
- * write to the WM8728 register space
- */
-static int wm8728_write(struct snd_soc_codec *codec, unsigned int reg,
-        unsigned int value)
-{
-        u8 data[2];
-
-        /* data is
-         *   D15..D9 WM8728 register offset
-         *   D8...D0 register data
-         */
-        data[0] = (reg << 1) | ((value >> 8) & 0x0001);
-        data[1] = value & 0x00ff;
-
-        wm8728_write_reg_cache(codec, reg, value);
-
-        if (codec->hw_write(codec->control_data, data, 2) == 2)
-                return 0;
-        else
-                return -EIO;
-}
-
 static const DECLARE_TLV_DB_SCALE(wm8728_tlv, -12750, 50, 1);
 
 static const struct snd_kcontrol_new wm8728_snd_controls[] = {
@@ -121,12 +82,12 @@ static int wm8728_add_widgets(struct snd_soc_codec *codec)
 static int wm8728_mute(struct snd_soc_dai *dai, int mute)
 {
         struct snd_soc_codec *codec = dai->codec;
-        u16 mute_reg = wm8728_read_reg_cache(codec, WM8728_DACCTL);
+        u16 mute_reg = snd_soc_read(codec, WM8728_DACCTL);
 
         if (mute)
-                wm8728_write(codec, WM8728_DACCTL, mute_reg | 1);
+                snd_soc_write(codec, WM8728_DACCTL, mute_reg | 1);
         else
-                wm8728_write(codec, WM8728_DACCTL, mute_reg & ~1);
+                snd_soc_write(codec, WM8728_DACCTL, mute_reg & ~1);
 
         return 0;
 }
@@ -138,7 +99,7 @@ static int wm8728_hw_params(struct snd_pcm_substream *substream,
         struct snd_soc_pcm_runtime *rtd = substream->private_data;
         struct snd_soc_device *socdev = rtd->socdev;
         struct snd_soc_codec *codec = socdev->card->codec;
-        u16 dac = wm8728_read_reg_cache(codec, WM8728_DACCTL);
+        u16 dac = snd_soc_read(codec, WM8728_DACCTL);
 
         dac &= ~0x18;
 
@@ -155,7 +116,7 @@ static int wm8728_hw_params(struct snd_pcm_substream *substream,
                 return -EINVAL;
         }
 
-        wm8728_write(codec, WM8728_DACCTL, dac);
+        snd_soc_write(codec, WM8728_DACCTL, dac);
 
         return 0;
 }
@@ -164,7 +125,7 @@ static int wm8728_set_dai_fmt(struct snd_soc_dai *codec_dai,
                 unsigned int fmt)
 {
         struct snd_soc_codec *codec = codec_dai->codec;
-        u16 iface = wm8728_read_reg_cache(codec, WM8728_IFCTL);
+        u16 iface = snd_soc_read(codec, WM8728_IFCTL);
 
         /* Currently only I2S is supported by the driver, though the
          * hardware is more flexible.
@@ -204,7 +165,7 @@ static int wm8728_set_dai_fmt(struct snd_soc_dai *codec_dai,
                 return -EINVAL;
         }
 
-        wm8728_write(codec, WM8728_IFCTL, iface);
+        snd_soc_write(codec, WM8728_IFCTL, iface);
         return 0;
 }
 
@@ -220,19 +181,19 @@ static int wm8728_set_bias_level(struct snd_soc_codec *codec,
         case SND_SOC_BIAS_STANDBY:
                 if (codec->bias_level == SND_SOC_BIAS_OFF) {
                         /* Power everything up... */
-                        reg = wm8728_read_reg_cache(codec, WM8728_DACCTL);
-                        wm8728_write(codec, WM8728_DACCTL, reg & ~0x4);
+                        reg = snd_soc_read(codec, WM8728_DACCTL);
+                        snd_soc_write(codec, WM8728_DACCTL, reg & ~0x4);
 
                         /* ..then sync in the register cache. */
                         for (i = 0; i < ARRAY_SIZE(wm8728_reg_defaults); i++)
-                                wm8728_write(codec, i,
-                                             wm8728_read_reg_cache(codec, i));
+                                snd_soc_write(codec, i,
+                                             snd_soc_read(codec, i));
                 }
                 break;
 
         case SND_SOC_BIAS_OFF:
-                reg = wm8728_read_reg_cache(codec, WM8728_DACCTL);
-                wm8728_write(codec, WM8728_DACCTL, reg | 0x4);
+                reg = snd_soc_read(codec, WM8728_DACCTL);
+                snd_soc_write(codec, WM8728_DACCTL, reg | 0x4);
                 break;
         }
         codec->bias_level = level;
@@ -294,8 +255,6 @@ static int wm8728_init(struct snd_soc_device *socdev)
 
         codec->name = "WM8728";
         codec->owner = THIS_MODULE;
-        codec->read = wm8728_read_reg_cache;
-        codec->write = wm8728_write;
         codec->set_bias_level = wm8728_set_bias_level;
         codec->dai = &wm8728_dai;
         codec->num_dai = 1;
@@ -307,11 +266,18 @@ static int wm8728_init(struct snd_soc_device *socdev)
         if (codec->reg_cache == NULL)
                 return -ENOMEM;
 
+        ret = snd_soc_codec_set_cache_io(codec, 7, 9);
+        if (ret < 0) {
+                printk(KERN_ERR "wm8728: failed to configure cache I/O: %d\n",
+                       ret);
+                goto err;
+        }
+
         /* register pcms */
         ret = snd_soc_new_pcms(socdev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1);
         if (ret < 0) {
                 printk(KERN_ERR "wm8728: failed to create pcms\n");
-                goto pcm_err;
+                goto err;
         }
 
         /* power on device */
@@ -331,7 +297,7 @@ static int wm8728_init(struct snd_soc_device *socdev)
 card_err:
         snd_soc_free_pcms(socdev);
         snd_soc_dapm_free(socdev);
-pcm_err:
+err:
         kfree(codec->reg_cache);
         return ret;
 }