[PATCH v6 8/8] ASoC: sam9x5: get codec MCLK via device tree

From: Richard Genoud
Date: Tue Jul 30 2013 - 06:00:59 EST


Instead of having the clock rate hard coded, and thus, only compatible
with one board, we can make it compatible with other implementations.

Signed-off-by: Richard Genoud <richard.genoud@xxxxxxxxx>
---
.../bindings/sound/atmel-sam9x5-wm8731-audio.txt | 4 ++++
arch/arm/boot/dts/at91sam9x5ek.dtsi | 8 ++++++++
sound/soc/atmel/sam9x5_wm8731.c | 18 ++++++++++++++----
3 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/sound/atmel-sam9x5-wm8731-audio.txt b/Documentation/devicetree/bindings/sound/atmel-sam9x5-wm8731-audio.txt
index 0720857..114a4c5 100644
--- a/Documentation/devicetree/bindings/sound/atmel-sam9x5-wm8731-audio.txt
+++ b/Documentation/devicetree/bindings/sound/atmel-sam9x5-wm8731-audio.txt
@@ -8,6 +8,8 @@ Required properties:
- atmel,audio-routing: A list of the connections between audio components.
Each entry is a pair of strings, the first being the connection's sink,
the second being the connection's source.
+ - clocks: Must contain an entry for the codec master clock.
+ - clock-names : Must be "mclk" (clock that feeds the codec master clock)

Available audio endpoints for the audio-routing table:

@@ -32,4 +34,6 @@ sound {

atmel,ssc-controller = <&ssc0>;
atmel,audio-codec = <&wm8731>;
+ clocks = <&sound_crystal 0>;
+ clock-names = "mclk";
};
diff --git a/arch/arm/boot/dts/at91sam9x5ek.dtsi b/arch/arm/boot/dts/at91sam9x5ek.dtsi
index 9afe15b..b5ff17c 100644
--- a/arch/arm/boot/dts/at91sam9x5ek.dtsi
+++ b/arch/arm/boot/dts/at91sam9x5ek.dtsi
@@ -114,6 +114,12 @@
};
};

+ sound_crystal: osc@0 {
+ compatible = "fixed-clock";
+ #clock-cells = <0>;
+ clock-frequency = <12288000>;
+ };
+
sound {
compatible = "atmel,sam9x5-wm8731-audio";

@@ -127,5 +133,7 @@

atmel,ssc-controller = <&ssc0>;
atmel,audio-codec = <&wm8731>;
+ clocks = <&sound_crystal 0>;
+ clock-names = "mclk";
};
};
diff --git a/sound/soc/atmel/sam9x5_wm8731.c b/sound/soc/atmel/sam9x5_wm8731.c
index 992ae38..f33c181 100644
--- a/sound/soc/atmel/sam9x5_wm8731.c
+++ b/sound/soc/atmel/sam9x5_wm8731.c
@@ -23,6 +23,8 @@
#include <linux/mod_devicetable.h>
#include <linux/platform_device.h>
#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/clk.h>

#include <sound/soc.h>
#include <sound/soc-dai.h>
@@ -31,12 +33,10 @@
#include "../codecs/wm8731.h"
#include "atmel_ssc_dai.h"

-
-#define MCLK_RATE 12288000
-
#define DRV_NAME "sam9x5-snd-wm8731"

struct sam9x5_drvdata {
+ struct clk *mclk;
int ssc_id;
};

@@ -46,6 +46,7 @@ struct sam9x5_drvdata {
static int sam9x5_wm8731_init(struct snd_soc_pcm_runtime *rtd)
{
struct snd_soc_dai *codec_dai = rtd->codec_dai;
+ struct sam9x5_drvdata *priv = snd_soc_card_get_drvdata(rtd->card);
struct device *dev = rtd->dev;
int ret;

@@ -53,7 +54,8 @@ static int sam9x5_wm8731_init(struct snd_soc_pcm_runtime *rtd)

/* set the codec system clock for DAC and ADC */
ret = snd_soc_dai_set_sysclk(codec_dai, WM8731_SYSCLK_XTAL,
- MCLK_RATE, SND_SOC_CLOCK_IN);
+ clk_get_rate(priv->mclk),
+ SND_SOC_CLOCK_IN);
if (ret < 0) {
dev_err(dev, "ASoC: Failed to set WM8731 SYSCLK: %d\n", ret);
return ret;
@@ -142,6 +144,13 @@ static int sam9x5_wm8731_driver_probe(struct platform_device *pdev)

priv->ssc_id = of_alias_get_id(cpu_np, "ssc");

+ priv->mclk = devm_clk_get(&pdev->dev, "mclk");
+ if (IS_ERR(priv->mclk)) {
+ ret = PTR_ERR(priv->mclk);
+ dev_err(&pdev->dev, "Failed to get MCLK: %d\n", ret);
+ goto out;
+ }
+
ret = atmel_ssc_set_audio(priv->ssc_id);
if (ret != 0) {
dev_err(&pdev->dev,
@@ -153,6 +162,7 @@ static int sam9x5_wm8731_driver_probe(struct platform_device *pdev)
of_node_put(codec_np);
of_node_put(cpu_np);

+ snd_soc_card_set_drvdata(card, priv);
platform_set_drvdata(pdev, card);

ret = snd_soc_register_card(card);
--
1.7.10.4

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