linux-kernel - [PATCH] ASoC: samsung: Add 'mclk' handling for Snow sound-card driver

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <1400559942-5666-1-git-send-email-tushar.behera@linaro.org>
Date:	Tue, 20 May 2014 09:55:42 +0530
From:	Tushar Behera <tushar.behera@...aro.org>
To:	alsa-devel@...a-project.org, linux-samsung-soc@...r.kernel.org,
	linux-kernel@...r.kernel.org, devicetree@...r.kernel.org,
	linux-doc@...r.kernel.org
Cc:	lgirdwood@...il.com, robh+dt@...nel.org, sbkim73@...sung.com,
	rdunlap@...radead.org, broonie@...nel.org, dianders@...omium.org,
	t.figa@...sung.com
Subject: [PATCH] ASoC: samsung: Add 'mclk' handling for Snow sound-card driver

For audio to work on Snow board, we need the codec master clock 'mclk'
to be properly configured.

Currently XCLKOUT is configured as 'mclk' for codec chip and it is
required to be clocked at 24MHz for the codec to work properly.

Add appropriate clock handling within Snow sound-card driver to set
'mclk' to operate at 24MHz.

Signed-off-by: Tushar Behera <tushar.behera@...aro.org>
---
 Documentation/devicetree/bindings/sound/snow.txt |    7 ++++++
 sound/soc/samsung/snow.c                         |   26 +++++++++++++++++++++-
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/sound/snow.txt b/Documentation/devicetree/bindings/sound/snow.txt
index 678b191..94dd29c 100644
--- a/Documentation/devicetree/bindings/sound/snow.txt
+++ b/Documentation/devicetree/bindings/sound/snow.txt
@@ -7,6 +7,10 @@ Required properties:
 - samsung,i2s-controller: The phandle of the Samsung I2S controller
 - samsung,audio-codec: The phandle of the audio codec
 
+Optional properties:
+- clocks: The phandle of the master clock to audio codec
+- clock-names: Should be "mclk"
+
 Example:
 
 sound {
@@ -14,4 +18,7 @@ sound {
 
 		samsung,i2s-controller = <&i2s0>;
 		samsung,audio-codec = <&max98095>;
+
+		clocks = <&pmu_system_controller>;
+		clock-names = "mclk";
 };
diff --git a/sound/soc/samsung/snow.c b/sound/soc/samsung/snow.c
index 014c177..c910739 100644
--- a/sound/soc/samsung/snow.c
+++ b/sound/soc/samsung/snow.c
@@ -15,13 +15,18 @@
 #include <linux/platform_device.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
+#include <linux/clk.h>
 
 #include <sound/soc.h>
 
 #include "i2s.h"
 
+/* Desired clock rate for codec mclk */
 #define FIN_PLL_RATE		24000000
 
+static struct clk *mclk;
+static unsigned long mclk_rate;
+
 static struct snd_soc_dai_link snow_dai[] = {
 	{
 		.name = "Primary",
@@ -41,7 +46,7 @@ static int snow_late_probe(struct snd_soc_card *card)
 
 	/* Set the MCLK rate for the codec */
 	ret = snd_soc_dai_set_sysclk(codec_dai, 0,
-					FIN_PLL_RATE, SND_SOC_CLOCK_IN);
+					mclk_rate, SND_SOC_CLOCK_IN);
 	if (ret < 0)
 		return ret;
 
@@ -68,6 +73,16 @@ static int snow_probe(struct platform_device *pdev)
 	struct device_node *i2s_node, *codec_node;
 	int i, ret;
 
+	/* The codec MCLK should be clocked at 24MHz */
+	mclk = devm_clk_get(&pdev->dev, "mclk");
+	if (!IS_ERR(mclk)) {
+		clk_prepare_enable(mclk);
+		clk_set_rate(mclk, FIN_PLL_RATE);
+		mclk_rate = clk_get_rate(mclk);
+	} else {
+		mclk_rate = FIN_PLL_RATE;
+	}
+
 	i2s_node = of_parse_phandle(pdev->dev.of_node,
 				    "samsung,i2s-controller", 0);
 	if (!i2s_node) {
@@ -101,6 +116,14 @@ static int snow_probe(struct platform_device *pdev)
 	return ret;
 }
 
+static int snow_remove(struct platform_device *pdev)
+{
+	if (!IS_ERR(mclk))
+		clk_disable_unprepare(mclk);
+
+	return 0;
+}
+
 static const struct of_device_id snow_of_match[] = {
 	{ .compatible = "google,snow-audio-max98090", },
 	{ .compatible = "google,snow-audio-max98095", },
@@ -115,6 +138,7 @@ static struct platform_driver snow_driver = {
 		.of_match_table = snow_of_match,
 	},
 	.probe = snow_probe,
+	.remove = snow_remove,
 };
 
 module_platform_driver(snow_driver);
-- 
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/