[alsa-devel] [PATCH] ASoC: AMD: Enable clk in startup intead of hw_params

[Yu-Hsuan Hsu]

Some usages only call startup and shutdown without setting hw_params
(e.g. arecord --dump-hw-params). If we don't enable clk in startup, it
will cause ref count error because the clk will be disabled in shutdown.
For this reason, we should move enabling clk from hw_params to startup.

In addition, the hw_params is fixed in this driver(48000 rate, 2
channels, S16_LE format) so we don't need to change the clk rate after
the hw_params is set.

Signed-off-by: Yu-Hsuan Hsu <yuhsuan at chromium.org>
---
 sound/soc/amd/acp-da7219-max98357a.c | 46 +++++++++-------------------
 1 file changed, 14 insertions(+), 32 deletions(-)

diff --git a/sound/soc/amd/acp-da7219-max98357a.c b/sound/soc/amd/acp-da7219-max98357a.c
index f4ee6798154af5..7a5621e5e2330d 100644
--- a/sound/soc/amd/acp-da7219-max98357a.c
+++ b/sound/soc/amd/acp-da7219-max98357a.c
@@ -96,14 +96,19 @@ static int cz_da7219_init(struct snd_soc_pcm_runtime *rtd)
 	return 0;
 }
 
-static int da7219_clk_enable(struct snd_pcm_substream *substream,
-			     int wclk_rate, int bclk_rate)
+static int da7219_clk_enable(struct snd_pcm_substream *substream)
 {
 	int ret = 0;
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 
-	clk_set_rate(da7219_dai_wclk, wclk_rate);
-	clk_set_rate(da7219_dai_bclk, bclk_rate);
+	/*
+	 * Set wclk to 48000 because the rate constraint of this driver is
+	 * 48000. ADAU7002 spec: "The ADAU7002 requires a BCLK rate that is
+	 * minimum of 64x the LRCLK sample rate." DA7219 is the only clk
+	 * source so for all codecs we have to limit bclk to 64X lrclk.
+	 */
+	clk_set_rate(da7219_dai_wclk, 48000);
+	clk_set_rate(da7219_dai_bclk, 48000 * 64);
 	ret = clk_prepare_enable(da7219_dai_bclk);
 	if (ret < 0) {
 		dev_err(rtd->dev, "can't enable master clock %d\n", ret);
@@ -156,7 +161,7 @@ static int cz_da7219_play_startup(struct snd_pcm_substream *substream)
 				   &constraints_rates);
 
 	machine->play_i2s_instance = I2S_SP_INSTANCE;
-	return 0;
+	return da7219_clk_enable(substream);
 }
 
 static int cz_da7219_cap_startup(struct snd_pcm_substream *substream)
@@ -178,7 +183,7 @@ static int cz_da7219_cap_startup(struct snd_pcm_substream *substream)
 
 	machine->cap_i2s_instance = I2S_SP_INSTANCE;
 	machine->capture_channel = CAP_CHANNEL1;
-	return 0;
+	return da7219_clk_enable(substream);
 }
 
 static int cz_max_startup(struct snd_pcm_substream *substream)
@@ -199,7 +204,7 @@ static int cz_max_startup(struct snd_pcm_substream *substream)
 				   &constraints_rates);
 
 	machine->play_i2s_instance = I2S_BT_INSTANCE;
-	return 0;
+	return da7219_clk_enable(substream);
 }
 
 static int cz_dmic0_startup(struct snd_pcm_substream *substream)
@@ -220,7 +225,7 @@ static int cz_dmic0_startup(struct snd_pcm_substream *substream)
 				   &constraints_rates);
 
 	machine->cap_i2s_instance = I2S_BT_INSTANCE;
-	return 0;
+	return da7219_clk_enable(substream);
 }
 
 static int cz_dmic1_startup(struct snd_pcm_substream *substream)
@@ -242,25 +247,7 @@ static int cz_dmic1_startup(struct snd_pcm_substream *substream)
 
 	machine->cap_i2s_instance = I2S_SP_INSTANCE;
 	machine->capture_channel = CAP_CHANNEL0;
-	return 0;
-}
-
-static int cz_da7219_params(struct snd_pcm_substream *substream,
-				      struct snd_pcm_hw_params *params)
-{
-	int wclk, bclk;
-
-	wclk = params_rate(params);
-	bclk = wclk * params_channels(params) *
-		snd_pcm_format_width(params_format(params));
-	/* ADAU7002 spec: "The ADAU7002 requires a BCLK rate
-	 * that is minimum of 64x the LRCLK sample rate."
-	 * DA7219 is the only clk source so for all codecs
-	 * we have to limit bclk to 64X lrclk.
-	 */
-	if (bclk < (wclk * 64))
-		bclk = wclk * 64;
-	return da7219_clk_enable(substream, wclk, bclk);
+	return da7219_clk_enable(substream);
 }
 
 static void cz_da7219_shutdown(struct snd_pcm_substream *substream)
@@ -271,31 +258,26 @@ static void cz_da7219_shutdown(struct snd_pcm_substream *substream)
 static const struct snd_soc_ops cz_da7219_play_ops = {
 	.startup = cz_da7219_play_startup,
 	.shutdown = cz_da7219_shutdown,
-	.hw_params = cz_da7219_params,
 };
 
 static const struct snd_soc_ops cz_da7219_cap_ops = {
 	.startup = cz_da7219_cap_startup,
 	.shutdown = cz_da7219_shutdown,
-	.hw_params = cz_da7219_params,
 };
 
 static const struct snd_soc_ops cz_max_play_ops = {
 	.startup = cz_max_startup,
 	.shutdown = cz_da7219_shutdown,
-	.hw_params = cz_da7219_params,
 };
 
 static const struct snd_soc_ops cz_dmic0_cap_ops = {
 	.startup = cz_dmic0_startup,
 	.shutdown = cz_da7219_shutdown,
-	.hw_params = cz_da7219_params,
 };
 
 static const struct snd_soc_ops cz_dmic1_cap_ops = {
 	.startup = cz_dmic1_startup,
 	.shutdown = cz_da7219_shutdown,
-	.hw_params = cz_da7219_params,
 };
 
 SND_SOC_DAILINK_DEF(designware1,
-- 
2.24.0.432.g9d3f5f5b63-goog