[alsa-devel] [PATCH] ASoC: fsl: imx-wm8962: Grant hw_params() permission to reprogram FLL
Nicolin Chen
Guangyu.Chen at freescale.com
Wed Dec 25 11:37:15 CET 2013
From: Nicolin Chen <b42378 at freescale.com>
Previously, we couldn't use hw_params() to reclock FLL becuase there might
be a race between two simmultaneous substreams so the FLL reprogramming
would be changed and accordingly mulfunction. Also it wouldn't make sense
for analogue bypass path feature of WM8962. So we adopted the DAPM way to
control it. However, if we want to playback a different sample rate file,
we need to wait for DAPM to change its bias_level and reconfigure FLL.
After we introduced full symmetry protection in the soc-pcm, we don't need
to worry about the race any more. And the instance by using hw_params() to
reprogram FLL will allow us to support flexible use cases -- for example:
'aplay -Dhw:0 44k16bit.wav 48k24bit.wav 32k16bit.wav'.
Thus this patch mainly adds FLL reprogramming code to hw_params() so as to
enchance the sound card's capability. Meanwhile in order not to break the
analogue bypass path feature, we make both set_bias_level() and hw_params()
ways coexist by only reclocking FLL if requiring a different frequency and
meanwhile not running any analogue bypass path in the background.
Signed-off-by: Nicolin Chen <Guangyu.Chen at freescale.com>
---
sound/soc/fsl/imx-wm8962.c | 167 ++++++++++++++++++++++++++++++++-------------
1 file changed, 121 insertions(+), 46 deletions(-)
diff --git a/sound/soc/fsl/imx-wm8962.c b/sound/soc/fsl/imx-wm8962.c
index 3fd76bc..9621909 100644
--- a/sound/soc/fsl/imx-wm8962.c
+++ b/sound/soc/fsl/imx-wm8962.c
@@ -17,6 +17,7 @@
#include <linux/of_platform.h>
#include <linux/i2c.h>
#include <linux/slab.h>
+#include <linux/spinlock.h>
#include <linux/clk.h>
#include <sound/soc.h>
#include <sound/pcm_params.h>
@@ -35,6 +36,8 @@ struct imx_wm8962_data {
char platform_name[DAI_NAME_SIZE];
struct clk *codec_clk;
unsigned int clk_frequency;
+ unsigned int fll_frequency;
+ spinlock_t fll_lock;
};
struct imx_priv {
@@ -50,15 +53,125 @@ static const struct snd_soc_dapm_widget imx_wm8962_dapm_widgets[] = {
};
static int sample_rate = 44100;
+static unsigned int fll_frequency = 44100 * 256;
static snd_pcm_format_t sample_format = SNDRV_PCM_FORMAT_S16_LE;
+static inline u32 imx_wm8962_calculate_fll(u32 rate, snd_pcm_format_t format)
+{
+ switch (format) {
+ case SNDRV_PCM_FORMAT_S24_LE:
+ return rate * 384;
+ default:
+ return rate * 256;
+ }
+}
+
+static int imx_wm8962_enable_fll(struct snd_soc_dai *codec_dai)
+{
+ struct imx_priv *priv = &card_priv;
+ struct device *dev = &priv->pdev->dev;
+ struct imx_wm8962_data *data = platform_get_drvdata(priv->pdev);
+ u32 ret = 0;
+
+ spin_lock(&data->fll_lock);
+
+ /* Protect FLL if it has not been disabled */
+ if (data->fll_frequency)
+ goto err_unlock;
+
+ ret = snd_soc_dai_set_pll(codec_dai, WM8962_FLL, WM8962_FLL_MCLK,
+ data->clk_frequency, fll_frequency);
+ if (ret) {
+ dev_err(dev, "failed to start FLL: %d\n", ret);
+ goto err_unlock;
+ }
+
+ ret = snd_soc_dai_set_sysclk(codec_dai, WM8962_SYSCLK_FLL,
+ fll_frequency, SND_SOC_CLOCK_IN);
+ if (ret)
+ dev_err(dev, "failed to set SYSCLK: %d\n", ret);
+
+ data->fll_frequency = fll_frequency;
+
+err_unlock:
+ spin_unlock(&data->fll_lock);
+
+ return ret;
+}
+
+static int imx_wm8962_disable_fll(struct snd_soc_dai *codec_dai)
+{
+ struct imx_priv *priv = &card_priv;
+ struct device *dev = &priv->pdev->dev;
+ struct imx_wm8962_data *data = platform_get_drvdata(priv->pdev);
+ int ret = 0;
+
+ spin_lock(&data->fll_lock);
+
+ if (!data->fll_frequency)
+ goto err_unlock;
+
+ /* Switch to MCLK as sysclk once so as to disable FLL */
+ ret = snd_soc_dai_set_sysclk(codec_dai, WM8962_SYSCLK_MCLK,
+ 0, SND_SOC_CLOCK_IN);
+ if (ret) {
+ dev_err(dev, "failed to switch away from FLL: %d\n", ret);
+ goto err_unlock;
+ }
+
+ /* Disable FLL so that we can reset its output freq later */
+ ret = snd_soc_dai_set_pll(codec_dai, WM8962_FLL,
+ WM8962_FLL_MCLK, 0, 0);
+ if (ret)
+ dev_err(dev, "failed to stop FLL: %d\n", ret);
+
+ data->fll_frequency = 0;
+
+err_unlock:
+ spin_unlock(&data->fll_lock);
+
+ return ret;
+}
+
+static int imx_wm8962_reprogram_fll(struct snd_pcm_substream *substream)
+{
+ struct imx_priv *priv = &card_priv;
+ struct imx_wm8962_data *data = platform_get_drvdata(priv->pdev);
+ struct snd_soc_pcm_runtime *rtd = substream->private_data;
+ struct snd_soc_dai *codec_dai = rtd->codec_dai;
+ struct snd_soc_codec *codec = rtd->codec;
+ u32 mask, ret = 0;
+
+ mask = WM8962_MIXINL_TO_HPMIXL_MASK | WM8962_MIXINR_TO_HPMIXL_MASK |
+ WM8962_IN4L_TO_HPMIXL_MASK | WM8962_IN4R_TO_HPMIXL_MASK;
+ ret |= snd_soc_read(codec, WM8962_HEADPHONE_MIXER_1) & mask;
+ ret |= snd_soc_read(codec, WM8962_HEADPHONE_MIXER_2) & mask;
+ ret |= snd_soc_read(codec, WM8962_SPEAKER_MIXER_1) & mask;
+ ret |= snd_soc_read(codec, WM8962_SPEAKER_MIXER_2) & mask;
+
+ spin_lock(&data->fll_lock);
+ /* Do not reprogram FLL if not changed or running analogue bypass */
+ if (fll_frequency == data->fll_frequency || ret) {
+ spin_unlock(&data->fll_lock);
+ return 0;
+ }
+ spin_unlock(&data->fll_lock);
+
+ ret = imx_wm8962_disable_fll(codec_dai);
+ if (ret)
+ return ret;
+
+ return imx_wm8962_enable_fll(codec_dai);
+}
+
static int imx_hifi_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params)
{
sample_rate = params_rate(params);
sample_format = params_format(params);
+ fll_frequency = imx_wm8962_calculate_fll(sample_rate, sample_format);
- return 0;
+ return imx_wm8962_reprogram_fll(substream);
}
static struct snd_soc_ops imx_hifi_ops = {
@@ -70,60 +183,19 @@ static int imx_wm8962_set_bias_level(struct snd_soc_card *card,
enum snd_soc_bias_level level)
{
struct snd_soc_dai *codec_dai = card->rtd[0].codec_dai;
- struct imx_priv *priv = &card_priv;
- struct imx_wm8962_data *data = platform_get_drvdata(priv->pdev);
- struct device *dev = &priv->pdev->dev;
- unsigned int pll_out;
- int ret;
if (dapm->dev != codec_dai->dev)
return 0;
switch (level) {
case SND_SOC_BIAS_PREPARE:
- if (dapm->bias_level == SND_SOC_BIAS_STANDBY) {
- if (sample_format == SNDRV_PCM_FORMAT_S24_LE)
- pll_out = sample_rate * 384;
- else
- pll_out = sample_rate * 256;
-
- ret = snd_soc_dai_set_pll(codec_dai, WM8962_FLL,
- WM8962_FLL_MCLK, data->clk_frequency,
- pll_out);
- if (ret < 0) {
- dev_err(dev, "failed to start FLL: %d\n", ret);
- return ret;
- }
-
- ret = snd_soc_dai_set_sysclk(codec_dai,
- WM8962_SYSCLK_FLL, pll_out,
- SND_SOC_CLOCK_IN);
- if (ret < 0) {
- dev_err(dev, "failed to set SYSCLK: %d\n", ret);
- return ret;
- }
- }
+ if (dapm->bias_level == SND_SOC_BIAS_STANDBY)
+ return imx_wm8962_enable_fll(codec_dai);
break;
case SND_SOC_BIAS_STANDBY:
- if (dapm->bias_level == SND_SOC_BIAS_PREPARE) {
- ret = snd_soc_dai_set_sysclk(codec_dai,
- WM8962_SYSCLK_MCLK, data->clk_frequency,
- SND_SOC_CLOCK_IN);
- if (ret < 0) {
- dev_err(dev,
- "failed to switch away from FLL: %d\n",
- ret);
- return ret;
- }
-
- ret = snd_soc_dai_set_pll(codec_dai, WM8962_FLL,
- 0, 0, 0);
- if (ret < 0) {
- dev_err(dev, "failed to stop FLL: %d\n", ret);
- return ret;
- }
- }
+ if (dapm->bias_level == SND_SOC_BIAS_PREPARE)
+ return imx_wm8962_disable_fll(codec_dai);
break;
default:
@@ -225,6 +297,9 @@ static int imx_wm8962_probe(struct platform_device *pdev)
goto fail;
}
+ data->fll_frequency = 0;
+ spin_lock_init(&data->fll_lock);
+
data->codec_clk = devm_clk_get(&codec_dev->dev, NULL);
if (IS_ERR(data->codec_clk)) {
ret = PTR_ERR(data->codec_clk);
--
1.8.4
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