ASoC: samsung: Add sound card driver for Snow board

Added machine driver to instantiate I2S based sound card on Snow
board. It has MAX98095 audio codec on board.

There are some other variants for Snow board which have MAX98090
audio codec. Hence support for MAX98090 is also added to this
driver.
Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

Documentation/devicetree/bindings/sound/snow.txt

+Audio Binding for Snow boards
+
+Required properties:
+- compatible : Can be one of the following,
+			"google,snow-audio-max98090" or
+			"google,snow-audio-max98095"
+- samsung,i2s-controller: The phandle of the Samsung I2S controller
+- samsung,audio-codec: The phandle of the audio codec
+
+Example:
+
+sound {
+		compatible = "google,snow-audio-max98095";
+
+		samsung,i2s-controller = <&i2s0>;
+		samsung,audio-codec = <&max98095>;
+};

sound/soc/samsung/Kconfig

@@ -231,3 +231,13 @@ config SND_SOC_LITTLEMILL
 	select SND_SAMSUNG_I2S
 	select MFD_WM8994
 	select SND_SOC_WM8994
+
+config SND_SOC_SNOW
+	tristate "Audio support for Google Snow boards"
+	depends on SND_SOC_SAMSUNG
+	select SND_SOC_MAX98090
+	select SND_SOC_MAX98095
+	select SND_SAMSUNG_I2S
+	help
+	  Say Y if you want to add audio support for various Snow
+	  boards based on Exynos5 series of SoCs.

sound/soc/samsung/Makefile

@@ -34,6 +34,7 @@ snd-soc-h1940-uda1380-objs := h1940_uda1380.o
 snd-soc-rx1950-uda1380-objs := rx1950_uda1380.o
 snd-soc-smdk-wm8580-objs := smdk_wm8580.o
 snd-soc-smdk-wm8994-objs := smdk_wm8994.o
+snd-soc-snow-objs := snow.o
 snd-soc-smdk-wm9713-objs := smdk_wm9713.o
 snd-soc-s3c64xx-smartq-wm8987-objs := smartq_wm8987.o
 snd-soc-goni-wm8994-objs := goni_wm8994.o
@@ -58,6 +59,7 @@ obj-$(CONFIG_SND_SOC_SAMSUNG_H1940_UDA1380) += snd-soc-h1940-uda1380.o
 obj-$(CONFIG_SND_SOC_SAMSUNG_RX1950_UDA1380) += snd-soc-rx1950-uda1380.o
 obj-$(CONFIG_SND_SOC_SAMSUNG_SMDK_WM8580) += snd-soc-smdk-wm8580.o
 obj-$(CONFIG_SND_SOC_SAMSUNG_SMDK_WM8994) += snd-soc-smdk-wm8994.o
+obj-$(CONFIG_SND_SOC_SNOW) += snd-soc-snow.o
 obj-$(CONFIG_SND_SOC_SAMSUNG_SMDK_WM9713) += snd-soc-smdk-wm9713.o
 obj-$(CONFIG_SND_SOC_SMARTQ) += snd-soc-s3c64xx-smartq-wm8987.o
 obj-$(CONFIG_SND_SOC_SAMSUNG_SMDK_SPDIF) += snd-soc-smdk-spdif.o

sound/soc/samsung/snow.c

+/*
+ * ASoC machine driver for Snow boards
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+#include <sound/soc.h>
+
+#include "i2s.h"
+
+#define FIN_PLL_RATE		24000000
+
+static struct snd_soc_dai_link snow_dai[] = {
+	{
+		.name = "Primary",
+		.stream_name = "Primary",
+		.codec_dai_name = "HiFi",
+		.dai_fmt = SND_SOC_DAIFMT_I2S |
+				SND_SOC_DAIFMT_NB_NF |
+				SND_SOC_DAIFMT_CBS_CFS,
+	},
+};
+
+static int snow_late_probe(struct snd_soc_card *card)
+{
+	struct snd_soc_dai *codec_dai = card->rtd[0].codec_dai;
+	struct snd_soc_dai *cpu_dai = card->rtd[0].cpu_dai;
+	int ret;
+
+	/* Set the MCLK rate for the codec */
+	ret = snd_soc_dai_set_sysclk(codec_dai, 0,
+					FIN_PLL_RATE, SND_SOC_CLOCK_IN);
+	if (ret < 0)
+		return ret;
+
+	/* Select I2S Bus clock to set RCLK and BCLK */
+	ret = snd_soc_dai_set_sysclk(cpu_dai, SAMSUNG_I2S_RCLKSRC_0,
+					0, SND_SOC_CLOCK_IN);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static struct snd_soc_card snow_snd = {
+	.name = "Snow-I2S",
+	.dai_link = snow_dai,
+	.num_links = ARRAY_SIZE(snow_dai),
+
+	.late_probe = snow_late_probe,
+};
+
+static int snow_probe(struct platform_device *pdev)
+{
+	struct snd_soc_card *card = &snow_snd;
+	struct device_node *i2s_node, *codec_node;
+	int i, ret;
+
+	i2s_node = of_parse_phandle(pdev->dev.of_node,
+				    "samsung,i2s-controller", 0);
+	if (!i2s_node) {
+		dev_err(&pdev->dev,
+			"Property 'i2s-controller' missing or invalid\n");
+		return -EINVAL;
+	}
+
+	codec_node = of_parse_phandle(pdev->dev.of_node,
+				      "samsung,audio-codec", 0);
+	if (!codec_node) {
+		dev_err(&pdev->dev,
+			"Property 'audio-codec' missing or invalid\n");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(snow_dai); i++) {
+		snow_dai[i].codec_of_node = codec_node;
+		snow_dai[i].cpu_of_node = i2s_node;
+		snow_dai[i].platform_of_node = i2s_node;
+	}
+
+	card->dev = &pdev->dev;
+
+	ret = devm_snd_soc_register_card(&pdev->dev, card);
+	if (ret) {
+		dev_err(&pdev->dev, "snd_soc_register_card failed (%d)\n", ret);
+		return ret;
+	}
+
+	return ret;
+}
+
+static const struct of_device_id snow_of_match[] = {
+	{ .compatible = "google,snow-audio-max98090", },
+	{ .compatible = "google,snow-audio-max98095", },
+	{},
+};
+
+static struct platform_driver snow_driver = {
+	.driver = {
+		.name = "snow-audio",
+		.owner = THIS_MODULE,
+		.of_match_table = snow_of_match,
+	},
+	.probe = snow_probe,
+};
+
+module_platform_driver(snow_driver);
+
+MODULE_DESCRIPTION("ALSA SoC Audio machine driver for Snow");
+MODULE_LICENSE("GPL");