[alsa-devel] [PATCH v2 8/8] ASoC: qcom: apq8096: add kcontrols to set PCM rate

[Adam Serbinski]

This makes it possible for the backend sample rate to be
set to 8000 or 16000 Hz, depending on the needs of the HFP
call being set up.

Signed-off-by: Adam Serbinski <adam at serbinski.com>
CC: Andy Gross <agross at kernel.org>
CC: Mark Rutland <mark.rutland at arm.com>
CC: Liam Girdwood <lgirdwood at gmail.com>
CC: Patrick Lai <plai at codeaurora.org>
CC: Banajit Goswami <bgoswami at codeaurora.org>
CC: Jaroslav Kysela <perex at perex.cz>
CC: Takashi Iwai <tiwai at suse.com>
CC: alsa-devel at alsa-project.org
CC: linux-arm-msm at vger.kernel.org
CC: devicetree at vger.kernel.org
CC: linux-kernel at vger.kernel.org
---
 sound/soc/qcom/apq8096.c | 92 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 90 insertions(+), 2 deletions(-)

diff --git a/sound/soc/qcom/apq8096.c b/sound/soc/qcom/apq8096.c
index 1edcaa15234f..882f2c456321 100644
--- a/sound/soc/qcom/apq8096.c
+++ b/sound/soc/qcom/apq8096.c
@@ -16,6 +16,9 @@
 #define MI2S_BCLK_RATE			1536000
 #define PCM_BCLK_RATE			1024000
 
+static int pri_pcm_sample_rate = 16000;
+static int quat_pcm_sample_rate = 16000;
+
 static int msm_snd_hw_params(struct snd_pcm_substream *substream,
 			     struct snd_pcm_hw_params *params)
 {
@@ -33,10 +36,15 @@ static int msm_snd_hw_params(struct snd_pcm_substream *substream,
 	switch (cpu_dai->id) {
 	case PRIMARY_PCM_RX:
 	case PRIMARY_PCM_TX:
+		rate->min = pri_pcm_sample_rate;
+		rate->max = pri_pcm_sample_rate;
+		channels->min = 1;
+		channels->max = 1;
+		break;
 	case QUATERNARY_PCM_RX:
 	case QUATERNARY_PCM_TX:
-		rate->min = 16000;
-		rate->max = 16000;
+		rate->min = quat_pcm_sample_rate;
+		rate->max = quat_pcm_sample_rate;
 		channels->min = 1;
 		channels->max = 1;
 		break;
@@ -121,6 +129,83 @@ static struct snd_soc_ops apq8096_ops = {
 	.startup = msm_snd_startup,
 };
 
+static char const *pcm_sample_rate_text[] = {"8 kHz", "16 kHz"};
+static const struct soc_enum pcm_snd_enum =
+		SOC_ENUM_SINGLE_EXT(2, pcm_sample_rate_text);
+
+static int get_sample_rate_idx(int sample_rate)
+{
+	int sample_rate_idx = 0;
+
+	switch (sample_rate) {
+	case 8000:
+		sample_rate_idx = 0;
+		break;
+	case 16000:
+	default:
+		sample_rate_idx = 1;
+		break;
+	}
+
+	return sample_rate_idx;
+}
+
+static int pri_pcm_sample_rate_get(struct snd_kcontrol *kcontrol,
+				   struct snd_ctl_elem_value *ucontrol)
+{
+	ucontrol->value.integer.value[0] =
+		get_sample_rate_idx(pri_pcm_sample_rate);
+	return 0;
+}
+
+static int quat_pcm_sample_rate_get(struct snd_kcontrol *kcontrol,
+				    struct snd_ctl_elem_value *ucontrol)
+{
+	ucontrol->value.integer.value[0] =
+		get_sample_rate_idx(quat_pcm_sample_rate);
+	return 0;
+}
+
+static int get_sample_rate(int idx)
+{
+	int sample_rate_val = 0;
+
+	switch (idx) {
+	case 0:
+		sample_rate_val = 8000;
+		break;
+	case 1:
+	default:
+		sample_rate_val = 16000;
+		break;
+	}
+
+	return sample_rate_val;
+}
+
+static int pri_pcm_sample_rate_put(struct snd_kcontrol *kcontrol,
+				   struct snd_ctl_elem_value *ucontrol)
+{
+	pri_pcm_sample_rate =
+		get_sample_rate(ucontrol->value.integer.value[0]);
+	return 0;
+}
+
+static int quat_pcm_sample_rate_put(struct snd_kcontrol *kcontrol,
+				    struct snd_ctl_elem_value *ucontrol)
+{
+	quat_pcm_sample_rate =
+		get_sample_rate(ucontrol->value.integer.value[0]);
+	return 0;
+}
+
+static const struct snd_kcontrol_new card_controls[] = {
+	SOC_ENUM_EXT("PRI_PCM SampleRate", pcm_snd_enum,
+		     pri_pcm_sample_rate_get, pri_pcm_sample_rate_put),
+	SOC_ENUM_EXT("QUAT_PCM SampleRate", pcm_snd_enum,
+		     quat_pcm_sample_rate_get, quat_pcm_sample_rate_put),
+};
+
 static int apq8096_init(struct snd_soc_pcm_runtime *rtd)
 {
 	struct snd_soc_dai *codec_dai = rtd->codec_dai;
@@ -182,6 +267,9 @@ static int apq8096_platform_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_card_register;
 
+	snd_soc_add_card_controls(card, card_controls,
+				  ARRAY_SIZE(card_controls));
+
 	return 0;
 
 err_card_register:
-- 
2.21.1