[PATCH 0/2] ASoC: da7218: Small clocking related updates for driver

[PATCH 0/2] ASoC: da7218: Small clocking related updates for driver

[Adam Thomson]

This patch set contains two updates relating to clocking. The first removes the
32KHz PLL feature as this is no longer supported, and the second provides MCLK
effciency improvements to avoid unnecessary MCLK enabling.

Changes are based on v4.8-rc1 Linux kernel.

Adam Thomson (2):
  ASoC: da7218: Remove 32KHz PLL mode from driver
  ASoC: da7218: Improve driver efficiency with regards to MCLK usage

 sound/soc/codecs/da7218.c | 34 +++++++++++++++-------------------
 sound/soc/codecs/da7218.h |  2 --
 2 files changed, 15 insertions(+), 21 deletions(-)

--
1.9.3

[PATCH 1/2] ASoC: da7218: Remove 32KHz PLL mode from driver

[Adam Thomson]

Functionality has been removed in latest silicon variants. This
patch removes the feature from the driver to align.

Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
---
 sound/soc/codecs/da7218.c | 12 +++---------
 sound/soc/codecs/da7218.h |  2 --
 2 files changed, 3 insertions(+), 11 deletions(-)

diff --git a/sound/soc/codecs/da7218.c b/sound/soc/codecs/da7218.c
index 99ce23e..f443519 100644
--- a/sound/soc/codecs/da7218.c
+++ b/sound/soc/codecs/da7218.c
@@ -1819,7 +1819,7 @@ static int da7218_set_dai_sysclk(struct snd_soc_dai *codec_dai,
 	if (da7218->mclk_rate == freq)
 		return 0;
 
-	if (((freq < 2000000) && (freq != 32768)) || (freq > 54000000)) {
+	if ((freq < 2000000) || (freq > 54000000)) {
 		dev_err(codec_dai->dev, "Unsupported MCLK value %d\n",
 			freq);
 		return -EINVAL;
@@ -1866,11 +1866,8 @@ static int da7218_set_dai_pll(struct snd_soc_dai *codec_dai, int pll_id,
 	u32 freq_ref;
 	u64 frac_div;
 
-	/* Verify 32KHz, 2MHz - 54MHz MCLK provided, and set input divider */
-	if (da7218->mclk_rate == 32768) {
-		indiv_bits = DA7218_PLL_INDIV_9_TO_18_MHZ;
-		indiv = DA7218_PLL_INDIV_9_TO_18_MHZ_VAL;
-	} else if (da7218->mclk_rate < 2000000) {
+	/* Verify 2MHz - 54MHz MCLK provided, and set input divider */
+	if (da7218->mclk_rate < 2000000) {
 		dev_err(codec->dev, "PLL input clock %d below valid range\n",
 			da7218->mclk_rate);
 		return -EINVAL;
@@ -1911,9 +1908,6 @@ static int da7218_set_dai_pll(struct snd_soc_dai *codec_dai, int pll_id,
 	case DA7218_SYSCLK_PLL_SRM:
 		pll_ctrl |= DA7218_PLL_MODE_SRM;
 		break;
-	case DA7218_SYSCLK_PLL_32KHZ:
-		pll_ctrl |= DA7218_PLL_MODE_32KHZ;
-		break;
 	default:
 		dev_err(codec->dev, "Invalid PLL config\n");
 		return -EINVAL;
diff --git a/sound/soc/codecs/da7218.h b/sound/soc/codecs/da7218.h
index 477cd37..4f7ec21 100644
--- a/sound/soc/codecs/da7218.h
+++ b/sound/soc/codecs/da7218.h
@@ -888,7 +888,6 @@
 #define DA7218_PLL_MODE_BYPASS		(0x0 << 6)
 #define DA7218_PLL_MODE_NORMAL		(0x1 << 6)
 #define DA7218_PLL_MODE_SRM		(0x2 << 6)
-#define DA7218_PLL_MODE_32KHZ		(0x3 << 6)
 
 /* DA7218_PLL_FRAC_TOP = 0x92 */
 #define DA7218_PLL_FBDIV_FRAC_TOP_SHIFT	0
@@ -1371,7 +1370,6 @@ enum da7218_sys_clk {
 	DA7218_SYSCLK_MCLK = 0,
 	DA7218_SYSCLK_PLL,
 	DA7218_SYSCLK_PLL_SRM,
-	DA7218_SYSCLK_PLL_32KHZ
 };
 
 enum da7218_dev_id {
-- 
1.9.3

[PATCH 2/2] ASoC: da7218: Improve driver efficiency with regards to MCLK usage

[Adam Thomson]

Currently MCLK remains enabled during bias STANDBY state, and this
is not necessary. This patch updates the code to handle enabling
and disabling of MCLK, if provided, when moving between STANDBY
and PREPARE states, therefore saving power when no active streams
present.

Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
---
 sound/soc/codecs/da7218.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/sound/soc/codecs/da7218.c b/sound/soc/codecs/da7218.c
index f443519..e7f3e4c 100644
--- a/sound/soc/codecs/da7218.c
+++ b/sound/soc/codecs/da7218.c
@@ -2583,20 +2583,22 @@ static int da7218_set_bias_level(struct snd_soc_codec *codec,
 
 	switch (level) {
 	case SND_SOC_BIAS_ON:
-	case SND_SOC_BIAS_PREPARE:
 		break;
-	case SND_SOC_BIAS_STANDBY:
-		if (snd_soc_codec_get_bias_level(codec) == SND_SOC_BIAS_OFF) {
-			/* MCLK */
+	case SND_SOC_BIAS_PREPARE:
+		/* Enable MCLK for transition to ON state */
+		if (snd_soc_codec_get_bias_level(codec) == SND_SOC_BIAS_STANDBY) {
 			if (da7218->mclk) {
 				ret = clk_prepare_enable(da7218->mclk);
 				if (ret) {
-					dev_err(codec->dev,
-						"Failed to enable mclk\n");
+					dev_err(codec->dev, "Failed to enable mclk\n");
 					return ret;
 				}
 			}
+		}
 
+		break;
+	case SND_SOC_BIAS_STANDBY:
+		if (snd_soc_codec_get_bias_level(codec) == SND_SOC_BIAS_OFF) {
 			/* Master bias */
 			snd_soc_update_bits(codec, DA7218_REFERENCES,
 					    DA7218_BIAS_EN_MASK,
@@ -2606,6 +2608,10 @@ static int da7218_set_bias_level(struct snd_soc_codec *codec,
 			snd_soc_update_bits(codec, DA7218_LDO_CTRL,
 					    DA7218_LDO_EN_MASK,
 					    DA7218_LDO_EN_MASK);
+		} else {
+			/* Remove MCLK */
+			if (da7218->mclk)
+				clk_disable_unprepare(da7218->mclk);
 		}
 		break;
 	case SND_SOC_BIAS_OFF:
@@ -2619,10 +2625,6 @@ static int da7218_set_bias_level(struct snd_soc_codec *codec,
 			snd_soc_update_bits(codec, DA7218_REFERENCES,
 					    DA7218_BIAS_EN_MASK, 0);
 		}
-
-		/* MCLK */
-		if (da7218->mclk)
-			clk_disable_unprepare(da7218->mclk);
 		break;
 	}
 
-- 
1.9.3