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authorMark Brown <broonie@opensource.wolfsonmicro.com>2009-02-16 17:51:54 +0000
committerMark Brown <broonie@opensource.wolfsonmicro.com>2009-02-18 11:25:23 +0000
commit5de7f9b20069257aa5f0bb74723c8603adc5841a (patch)
tree076476094e6c9229c54c3d92a7a8625f48b42756 /sound/soc/atmel
parent40135ea07190316a789b2edfbf7c8131598bdf81 (diff)
downloadlinux-5de7f9b20069257aa5f0bb74723c8603adc5841a.tar.bz2
ASoC: Actively manage MCLK for AT91SAM9G20-EK
We have software control of the MCLK for the WM8731 so save a bit of power by actively managing it within the machine driver, enabling it only while the codec is active. Once ASoC supports multiple boards and doesn't require the soc-audio device the initial clock setup should be pushed down into the arch/arm code but for now this reduces merge issues. Tested-by: Sedji Gaouaou <sedji.gaouaou@atmel.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Diffstat (limited to 'sound/soc/atmel')
-rw-r--r--sound/soc/atmel/sam9g20_wm8731.c68
1 files changed, 65 insertions, 3 deletions
diff --git a/sound/soc/atmel/sam9g20_wm8731.c b/sound/soc/atmel/sam9g20_wm8731.c
index b7efdc8119d4..ab32514a858d 100644
--- a/sound/soc/atmel/sam9g20_wm8731.c
+++ b/sound/soc/atmel/sam9g20_wm8731.c
@@ -53,6 +53,9 @@
#include "atmel-pcm.h"
#include "atmel_ssc_dai.h"
+#define MCLK_RATE 12000000
+
+static struct clk *mclk;
static int at91sam9g20ek_startup(struct snd_pcm_substream *substream)
{
@@ -60,11 +63,12 @@ static int at91sam9g20ek_startup(struct snd_pcm_substream *substream)
struct snd_soc_dai *codec_dai = rtd->dai->codec_dai;
int ret;
- /* codec system clock is supplied by PCK0, set to 12MHz */
ret = snd_soc_dai_set_sysclk(codec_dai, WM8731_SYSCLK,
- 12000000, SND_SOC_CLOCK_IN);
- if (ret < 0)
+ MCLK_RATE, SND_SOC_CLOCK_IN);
+ if (ret < 0) {
+ clk_disable(mclk);
return ret;
+ }
return 0;
}
@@ -190,6 +194,31 @@ static struct snd_soc_ops at91sam9g20ek_ops = {
.shutdown = at91sam9g20ek_shutdown,
};
+static int at91sam9g20ek_set_bias_level(struct snd_soc_card *card,
+ enum snd_soc_bias_level level)
+{
+ static int mclk_on;
+ int ret = 0;
+
+ switch (level) {
+ case SND_SOC_BIAS_ON:
+ case SND_SOC_BIAS_PREPARE:
+ if (!mclk_on)
+ ret = clk_enable(mclk);
+ if (ret == 0)
+ mclk_on = 1;
+ break;
+
+ case SND_SOC_BIAS_OFF:
+ case SND_SOC_BIAS_STANDBY:
+ if (mclk_on)
+ clk_disable(mclk);
+ mclk_on = 0;
+ break;
+ }
+
+ return ret;
+}
static const struct snd_soc_dapm_widget at91sam9g20ek_dapm_widgets[] = {
SND_SOC_DAPM_MIC("Int Mic", NULL),
@@ -248,6 +277,7 @@ static struct snd_soc_card snd_soc_at91sam9g20ek = {
.platform = &atmel_soc_platform,
.dai_link = &at91sam9g20ek_dai,
.num_links = 1,
+ .set_bias_level = at91sam9g20ek_set_bias_level,
};
static struct wm8731_setup_data at91sam9g20ek_wm8731_setup = {
@@ -267,12 +297,38 @@ static int __init at91sam9g20ek_init(void)
{
struct atmel_ssc_info *ssc_p = at91sam9g20ek_dai.cpu_dai->private_data;
struct ssc_device *ssc = NULL;
+ struct clk *pllb;
int ret;
if (!machine_is_at91sam9g20ek())
return -ENODEV;
/*
+ * Codec MCLK is supplied by PCK0 - set it up.
+ */
+ mclk = clk_get(NULL, "pck0");
+ if (IS_ERR(mclk)) {
+ printk(KERN_ERR "ASoC: Failed to get MCLK\n");
+ ret = PTR_ERR(mclk);
+ goto err;
+ }
+
+ pllb = clk_get(NULL, "pllb");
+ if (IS_ERR(mclk)) {
+ printk(KERN_ERR "ASoC: Failed to get PLLB\n");
+ ret = PTR_ERR(mclk);
+ goto err_mclk;
+ }
+ ret = clk_set_parent(mclk, pllb);
+ clk_put(pllb);
+ if (ret != 0) {
+ printk(KERN_ERR "ASoC: Failed to set MCLK parent\n");
+ goto err_mclk;
+ }
+
+ clk_set_rate(mclk, MCLK_RATE);
+
+ /*
* Request SSC device
*/
ssc = ssc_request(0);
@@ -303,6 +359,10 @@ static int __init at91sam9g20ek_init(void)
return ret;
err_ssc:
+err_mclk:
+ clk_put(mclk);
+ mclk = NULL;
+err:
return ret;
}
@@ -320,6 +380,8 @@ static void __exit at91sam9g20ek_exit(void)
platform_device_unregister(at91sam9g20ek_snd_device);
at91sam9g20ek_snd_device = NULL;
+ clk_put(mclk);
+ mclk = NULL;
}
module_init(at91sam9g20ek_init);