[alsa-devel] [PATCH 4/6] ASoC: ad1980: make usage of register cache optional

[Uwe Kleine-König]

I'm hunting some problems where reading and writing to the codec doesn't
work.  In this case caching is in the way.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig at pengutronix.de>
---
 sound/soc/codecs/ad1980.c |   36 +++++++++++++++++++++++++++++-------
 1 files changed, 29 insertions(+), 7 deletions(-)

diff --git a/sound/soc/codecs/ad1980.c b/sound/soc/codecs/ad1980.c
index 82267e5..864e65d 100644
--- a/sound/soc/codecs/ad1980.c
+++ b/sound/soc/codecs/ad1980.c
@@ -33,6 +33,8 @@
 
 #include "ad1980.h"
 
+#define AC97_USE_CACHE 1
+#if AC97_USE_CACHE
 /*
  * AD1980 register cache
  */
@@ -54,6 +56,7 @@ static const u16 ad1980_reg[] = {
 	0x0000, 0x0000, 0x1001, 0x0000, /* 70 - 76 */
 	0x0000, 0x0000, 0x4144, 0x5370  /* 78 - 7e */
 };
+#endif
 
 static const char *ad1980_rec_sel[] = {"Mic", "CD", "NC", "AUX", "Line",
 		"Stereo Mix", "Mono Mix", "Phone"};
@@ -101,7 +104,9 @@ static unsigned int ac97_read(struct snd_soc_codec *codec,
 	unsigned int reg)
 {
 	u16 *cache = codec->reg_cache;
+	int ret;
 
+#if AC97_USE_CACHE
 	switch (reg) {
 	case AC97_RESET:
 	case AC97_INT_PAGING:
@@ -109,27 +114,38 @@ static unsigned int ac97_read(struct snd_soc_codec *codec,
 	case AC97_EXTENDED_STATUS:
 	case AC97_VENDOR_ID1:
 	case AC97_VENDOR_ID2:
-		return soc_ac97_ops.read(codec->ac97, reg);
+#endif
+		ret = soc_ac97_ops.read(codec->ac97, reg);
+#if AC97_USE_CACHE
 	default:
 		reg = reg >> 1;
 
 		if (reg >= ARRAY_SIZE(ad1980_reg))
-			return -EINVAL;
-
-		return cache[reg];
+			ret = -EINVAL;
+		else
+			ret = cache[reg];
 	}
+#endif
+
+	pr_debug("%s: reg=0x%02x, val=0x%04x\n", __func__, reg, ret);
+
+	return ret;
 }
 
 static int ac97_write(struct snd_soc_codec *codec, unsigned int reg,
 	unsigned int val)
 {
-	u16 *cache = codec->reg_cache;
+	pr_debug("%s: reg=0x%02x, val=0x%04x\n", __func__, reg, val);
 
 	soc_ac97_ops.write(codec->ac97, reg, val);
+
+#if AC97_USE_CACHE
 	reg = reg >> 1;
-	if (reg < ARRAY_SIZE(ad1980_reg))
+	if (reg < ARRAY_SIZE(ad1980_reg)) {
+		u16 *cache = codec->reg_cache;
 		cache[reg] = val;
-
+	}
+#endif
 	return 0;
 }
 
@@ -204,6 +220,7 @@ static int ad1980_soc_probe(struct platform_device *pdev)
 	codec = socdev->card->codec;
 	mutex_init(&codec->mutex);
 
+#if AC97_USE_CACHE
 	codec->reg_cache =
 		kzalloc(sizeof(u16) * ARRAY_SIZE(ad1980_reg), GFP_KERNEL);
 	if (codec->reg_cache == NULL) {
@@ -214,6 +231,7 @@ static int ad1980_soc_probe(struct platform_device *pdev)
 			ARRAY_SIZE(ad1980_reg));
 	codec->reg_cache_size = sizeof(u16) * ARRAY_SIZE(ad1980_reg);
 	codec->reg_cache_step = 2;
+#endif
 	codec->name = "AD1980";
 	codec->owner = THIS_MODULE;
 	codec->dai = &ad1980_dai;
@@ -279,9 +297,11 @@ pcm_err:
 	snd_soc_free_ac97_codec(codec);
 
 codec_err:
+#if AC97_USE_CACHE
 	kfree(codec->reg_cache);
 
 cache_err:
+#endif
 	kfree(socdev->card->codec);
 	socdev->card->codec = NULL;
 	return ret;
@@ -298,7 +318,9 @@ static int ad1980_soc_remove(struct platform_device *pdev)
 	snd_soc_dapm_free(socdev);
 	snd_soc_free_pcms(socdev);
 	snd_soc_free_ac97_codec(codec);
+#if AC97_USE_CACHE
 	kfree(codec->reg_cache);
+#endif
 	kfree(codec);
 	return 0;
 }
-- 
1.7.1