ASoC: da7213: Improve 32KHz mode PLL locking

To aid PLL in locking on to a 32KHz MCLK, some register mods
are made during PLL configuration, and when enabling the DAI,
to achieve the full range of sample rates.

Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/codecs/da7213.c b/sound/soc/codecs/da7213.c
index 94550d4..f756220 100644 (file)
--- a/sound/soc/codecs/da7213.c
+++ b/sound/soc/codecs/da7213.c
@@ -750,11 +750,18 @@ static int da7213_dai_event(struct snd_soc_dapm_widget *w,
                snd_soc_update_bits(codec, DA7213_PC_COUNT,
                                    DA7213_PC_FREERUN_MASK, 0);
 
-               /* Slave mode, if SRM not enabled no need for status checks */
+               /* If SRM not enabled then nothing more to do */
                pll_ctrl = snd_soc_read(codec, DA7213_PLL_CTRL);
                if (!(pll_ctrl & DA7213_PLL_SRM_EN))
                        return 0;
 
+               /* Assist 32KHz mode PLL lock */
+               if (pll_ctrl & DA7213_PLL_32K_MODE) {
+                       snd_soc_write(codec, 0xF0, 0x8B);
+                       snd_soc_write(codec, 0xF2, 0x03);
+                       snd_soc_write(codec, 0xF0, 0x00);
+               }
+
                /* Check SRM has locked */
                do {
                        pll_status = snd_soc_read(codec, DA7213_PLL_STATUS);
@@ -771,6 +778,14 @@ static int da7213_dai_event(struct snd_soc_dapm_widget *w,
 
                return 0;
        case SND_SOC_DAPM_POST_PMD:
+               /* Revert 32KHz PLL lock udpates if applied previously */
+               pll_ctrl = snd_soc_read(codec, DA7213_PLL_CTRL);
+               if (pll_ctrl & DA7213_PLL_32K_MODE) {
+                       snd_soc_write(codec, 0xF0, 0x8B);
+                       snd_soc_write(codec, 0xF2, 0x01);
+                       snd_soc_write(codec, 0xF0, 0x00);
+               }
+
                /* PC free-running */
                snd_soc_update_bits(codec, DA7213_PC_COUNT,
                                    DA7213_PC_FREERUN_MASK,
@@ -1428,6 +1443,14 @@ static int da7213_set_dai_pll(struct snd_soc_dai *codec_dai, int pll_id,
                            DA7213_PLL_INDIV_MASK | DA7213_PLL_MODE_MASK,
                            pll_ctrl);
 
+       /* Assist 32KHz mode PLL lock */
+       if (source == DA7213_SYSCLK_PLL_32KHZ) {
+               snd_soc_write(codec, 0xF0, 0x8B);
+               snd_soc_write(codec, 0xF1, 0x03);
+               snd_soc_write(codec, 0xF1, 0x01);
+               snd_soc_write(codec, 0xF0, 0x00);
+       }
+
        return 0;
 }