ASoC: littlemill: Use a widget to keep track of AIF2 clocking

Since we only need to clock AIF2 when it's actively in use start up the
FLL for it using a supply widget which supplies AIF2CLK. This both makes
the sequencing more robust and ensures we minimise power consumption.

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

1 files changed, 53 insertions, 33 deletions

diff --git a/sound/soc/samsung/littlemill.c b/sound/soc/samsung/littlemill.c
index fd5ac47371a1..c82c646b8a08 100644
--- a/sound/soc/samsung/littlemill.c
+++ b/sound/soc/samsung/littlemill.c
@@ -67,7 +67,6 @@ static int littlemill_set_bias_level_post(struct snd_soc_card *card,
                                                enum snd_soc_bias_level level)
 {
         struct snd_soc_dai *aif1_dai = card->rtd[0].codec_dai;
-        struct snd_soc_dai *aif2_dai = card->rtd[1].cpu_dai;
         int ret;
 
         if (dapm->dev != aif1_dai->dev)
@@ -75,20 +74,6 @@ static int littlemill_set_bias_level_post(struct snd_soc_card *card,
 
         switch (level) {
         case SND_SOC_BIAS_STANDBY:
-                ret = snd_soc_dai_set_sysclk(aif2_dai, WM8994_SYSCLK_MCLK2,
-                                             32768, SND_SOC_CLOCK_IN);
-                if (ret < 0) {
-                        pr_err("Failed to switch away from FLL2: %d\n", ret);
-                        return ret;
-                }
-
-                ret = snd_soc_dai_set_pll(aif2_dai, WM8994_FLL2,
-                                          0, 0, 0);
-                if (ret < 0) {
-                        pr_err("Failed to stop FLL2: %d\n", ret);
-                        return ret;
-                }
-
                 ret = snd_soc_dai_set_sysclk(aif1_dai, WM8994_SYSCLK_MCLK2,
                                              32768, SND_SOC_CLOCK_IN);
                 if (ret < 0) {
@@ -104,24 +89,6 @@ static int littlemill_set_bias_level_post(struct snd_soc_card *card,
                 }
                 break;
 
-        case SND_SOC_BIAS_PREPARE:
-                ret = snd_soc_dai_set_pll(aif2_dai, WM8994_FLL2,
-                                          WM8994_FLL_SRC_BCLK, 64 * 8000,
-                                          8000 * 256);
-                if (ret < 0) {
-                        pr_err("Failed to start FLL: %d\n", ret);
-                        return ret;
-                }
-
-                ret = snd_soc_dai_set_sysclk(aif2_dai, WM8994_SYSCLK_FLL2,
-                                             8000 * 256,
-                                             SND_SOC_CLOCK_IN);
-                if (ret < 0) {
-                        pr_err("Failed to set SYSCLK: %d\n", ret);
-                        return ret;
-                }
-                break;
-
         default:
                 break;
         }
@@ -197,11 +164,62 @@ static struct snd_soc_dai_link littlemill_dai[] = {
         },
 };
 
+static int bbclk_ev(struct snd_soc_dapm_widget *w,
+                    struct snd_kcontrol *kcontrol, int event)
+{
+        struct snd_soc_card *card = w->dapm->card;
+        struct snd_soc_dai *aif2_dai = card->rtd[1].cpu_dai;
+        int ret;
+
+        switch (event) {
+        case SND_SOC_DAPM_PRE_PMU:
+                ret = snd_soc_dai_set_pll(aif2_dai, WM8994_FLL2,
+                                          WM8994_FLL_SRC_BCLK, 64 * 8000,
+                                          8000 * 256);
+                if (ret < 0) {
+                        pr_err("Failed to start FLL: %d\n", ret);
+                        return ret;
+                }
+
+                ret = snd_soc_dai_set_sysclk(aif2_dai, WM8994_SYSCLK_FLL2,
+                                             8000 * 256,
+                                             SND_SOC_CLOCK_IN);
+                if (ret < 0) {
+                        pr_err("Failed to set SYSCLK: %d\n", ret);
+                        return ret;
+                }
+                break;
+        case SND_SOC_DAPM_POST_PMD:
+                ret = snd_soc_dai_set_sysclk(aif2_dai, WM8994_SYSCLK_MCLK2,
+                                             32768, SND_SOC_CLOCK_IN);
+                if (ret < 0) {
+                        pr_err("Failed to switch away from FLL2: %d\n", ret);
+                        return ret;
+                }
+
+                ret = snd_soc_dai_set_pll(aif2_dai, WM8994_FLL2,
+                                          0, 0, 0);
+                if (ret < 0) {
+                        pr_err("Failed to stop FLL2: %d\n", ret);
+                        return ret;
+                }
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
 static struct snd_soc_dapm_widget widgets[] = {
         SND_SOC_DAPM_HP("Headphone", NULL),
 
         SND_SOC_DAPM_MIC("AMIC", NULL),
         SND_SOC_DAPM_MIC("DMIC", NULL),
+
+        SND_SOC_DAPM_SUPPLY_S("Baseband Clock", -1, SND_SOC_NOPM, 0, 0,
+                              bbclk_ev,
+                              SND_SOC_DAPM_PRE_PMU | SND_SOC_DAPM_POST_PMD),
 };
 
 static struct snd_soc_dapm_route audio_paths[] = {
@@ -214,6 +232,8 @@ static struct snd_soc_dapm_route audio_paths[] = {
         { "DMIC", NULL, "MICBIAS2" },   /* Default for DMICBIAS jumper */
         { "DMIC1DAT", NULL, "DMIC" },
         { "DMIC2DAT", NULL, "DMIC" },
+
+        { "AIF2CLK", NULL, "Baseband Clock" },
 };
 
 static struct snd_soc_jack littlemill_headset;