ASoC: atmel: add wm8904 based audio machine driver

Add wm8904 based audio machine driver for Atmel EK board

The following ek board based on it
- at91sam9n12ek
- sama5d3xek (d31, d33, d34, d35)

Signed-off-by: Bo Shen <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

Documentation/devicetree/bindings/sound/atmel-wm8904.txt

···
+Atmel ASoC driver with wm8904 audio codec complex
+
+Required properties:
+  - compatible: "atmel,asoc-wm8904"
+  - atmel,model: The user-visible name of this sound complex.
+  - 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. Valid names for sources and
+    sinks are the WM8904's pins, and the jacks on the board:
+
+    WM8904 pins:
+
+    * IN1L
+    * IN1R
+    * IN2L
+    * IN2R
+    * IN3L
+    * IN3R
+    * HPOUTL
+    * HPOUTR
+    * LINEOUTL
+    * LINEOUTR
+    * MICBIAS
+
+    Board connectors:
+
+    * Headphone Jack
+    * Line In Jack
+    * Mic
+
+  - atmel,ssc-controller: The phandle of the SSC controller
+  - atmel,audio-codec: The phandle of the WM8904 audio codec
+
+Optional properties:
+  - pinctrl-names, pinctrl-0: Please refer to pinctrl-bindings.txt
+
+Example:
+sound {
+	compatible = "atmel,asoc-wm8904";
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_pck0_as_mck>;
+
+	atmel,model = "wm8904 @ AT91SAM9N12EK";
+
+	atmel,audio-routing =
+		"Headphone Jack", "HPOUTL",
+		"Headphone Jack", "HPOUTR",
+		"IN2L", "Line In Jack",
+		"IN2R", "Line In Jack",
+		"Mic", "MICBIAS",
+		"IN1L", "Mic";
+
+	atmel,ssc-controller = <&ssc0>;
+	atmel,audio-codec = <&wm8904>;
+};

sound/soc/atmel/Kconfig

···
 	  Say Y if you want to add support for SoC audio on WM8731-based
 	  AT91sam9g20 evaluation board.
 
+config SND_ATMEL_SOC_WM8904
+	tristate "Atmel ASoC driver for boards using WM8904 codec"
+	depends on ARCH_AT91 && ATMEL_SSC && SND_ATMEL_SOC
+	select SND_ATMEL_SOC_SSC
+	select SND_ATMEL_SOC_DMA
+	select SND_SOC_WM8904
+	help
+	  Say Y if you want to add support for Atmel ASoC driver for boards using
+	  WM8904 codec.
+
 config SND_AT91_SOC_AFEB9260
 	tristate "SoC Audio support for AFEB9260 board"
 	depends on ARCH_AT91 && ATMEL_SSC && ARCH_AT91 && MACH_AFEB9260 && SND_ATMEL_SOC

sound/soc/atmel/Makefile

···
 
 # AT91 Machine Support
 snd-soc-sam9g20-wm8731-objs := sam9g20_wm8731.o
+snd-atmel-soc-wm8904-objs := atmel_wm8904.o
 
 obj-$(CONFIG_SND_AT91_SOC_SAM9G20_WM8731) += snd-soc-sam9g20-wm8731.o
+obj-$(CONFIG_SND_ATMEL_SOC_WM8904) += snd-atmel-soc-wm8904.o
 obj-$(CONFIG_SND_AT91_SOC_AFEB9260) += snd-soc-afeb9260.o

sound/soc/atmel/atmel_wm8904.c

···
+/*
+ * atmel_wm8904 - Atmel ASoC driver for boards with WM8904 codec.
+ *
+ * Copyright (C) 2012 Atmel
+ *
+ * Author: Bo Shen <[e-mail]>
+ *
+ * GPLv2 or later
+ */
+
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/pinctrl/consumer.h>
+
+#include <sound/soc.h>
+
+#include "../codecs/wm8904.h"
+#include "atmel_ssc_dai.h"
+
+#define MCLK_RATE 32768
+
+static struct clk *mclk;
+
+static const struct snd_soc_dapm_widget atmel_asoc_wm8904_dapm_widgets[] = {
+	SND_SOC_DAPM_HP("Headphone Jack", NULL),
+	SND_SOC_DAPM_MIC("Mic", NULL),
+	SND_SOC_DAPM_LINE("Line In Jack", NULL),
+};
+
+static int atmel_asoc_wm8904_hw_params(struct snd_pcm_substream *substream,
+		struct snd_pcm_hw_params *params)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_dai *codec_dai = rtd->codec_dai;
+	int ret;
+
+	ret = snd_soc_dai_set_pll(codec_dai, WM8904_FLL_MCLK, WM8904_FLL_MCLK,
+		32768, params_rate(params) * 256);
+	if (ret < 0) {
+		pr_err("%s - failed to set wm8904 codec PLL.", __func__);
+		return ret;
+	}
+
+	/*
+	 * As here wm8904 use FLL output as its system clock
+	 * so calling set_sysclk won't care freq parameter
+	 * then we pass 0
+	 */
+	ret = snd_soc_dai_set_sysclk(codec_dai, WM8904_CLK_FLL,
+			0, SND_SOC_CLOCK_IN);
+	if (ret < 0) {
+		pr_err("%s -failed to set wm8904 SYSCLK\n", __func__);
+		return ret;
+	}
+
+	return 0;
+}
+
+static struct snd_soc_ops atmel_asoc_wm8904_ops = {
+	.hw_params = atmel_asoc_wm8904_hw_params,
+};
+
+static int atmel_set_bias_level(struct snd_soc_card *card,
+		struct snd_soc_dapm_context *dapm,
+		enum snd_soc_bias_level level)
+{
+	if (dapm->bias_level == SND_SOC_BIAS_STANDBY) {
+		switch (level) {
+		case SND_SOC_BIAS_PREPARE:
+			clk_prepare_enable(mclk);
+			break;
+		case SND_SOC_BIAS_OFF:
+			clk_disable_unprepare(mclk);
+			break;
+		default:
+			break;
+		}
+	}
+
+	return 0;
+};
+
+static struct snd_soc_dai_link atmel_asoc_wm8904_dailink = {
+	.name = "WM8904",
+	.stream_name = "WM8904 PCM",
+	.codec_dai_name = "wm8904-hifi",
+	.dai_fmt = SND_SOC_DAIFMT_I2S
+		| SND_SOC_DAIFMT_NB_NF
+		| SND_SOC_DAIFMT_CBM_CFM,
+	.ops = &atmel_asoc_wm8904_ops,
+};
+
+static struct snd_soc_card atmel_asoc_wm8904_card = {
+	.name = "atmel_asoc_wm8904",
+	.owner = THIS_MODULE,
+	.set_bias_level = atmel_set_bias_level,
+	.dai_link = &atmel_asoc_wm8904_dailink,
+	.num_links = 1,
+	.dapm_widgets = atmel_asoc_wm8904_dapm_widgets,
+	.num_dapm_widgets = ARRAY_SIZE(atmel_asoc_wm8904_dapm_widgets),
+	.fully_routed = true,
+};
+
+static int atmel_asoc_wm8904_dt_init(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct device_node *codec_np, *cpu_np;
+	struct snd_soc_card *card = &atmel_asoc_wm8904_card;
+	struct snd_soc_dai_link *dailink = &atmel_asoc_wm8904_dailink;
+	int ret;
+
+	if (!np) {
+		dev_err(&pdev->dev, "only device tree supported\n");
+		return -EINVAL;
+	}
+
+	ret = snd_soc_of_parse_card_name(card, "atmel,model");
+	if (ret) {
+		dev_err(&pdev->dev, "failed to parse card name\n");
+		return ret;
+	}
+
+	ret = snd_soc_of_parse_audio_routing(card, "atmel,audio-routing");
+	if (ret) {
+		dev_err(&pdev->dev, "failed to parse audio routing\n");
+		return ret;
+	}
+
+	cpu_np = of_parse_phandle(np, "atmel,ssc-controller", 0);
+	if (!cpu_np) {
+		dev_err(&pdev->dev, "failed to get dai and pcm info\n");
+		ret = -EINVAL;
+		return ret;
+	}
+	dailink->cpu_of_node = cpu_np;
+	dailink->platform_of_node = cpu_np;
+	of_node_put(cpu_np);
+
+	codec_np = of_parse_phandle(np, "atmel,audio-codec", 0);
+	if (!codec_np) {
+		dev_err(&pdev->dev, "failed to get codec info\n");
+		ret = -EINVAL;
+		return ret;
+	}
+	dailink->codec_of_node = codec_np;
+	of_node_put(codec_np);
+
+	return 0;
+}
+
+static int atmel_asoc_wm8904_probe(struct platform_device *pdev)
+{
+	struct snd_soc_card *card = &atmel_asoc_wm8904_card;
+	struct snd_soc_dai_link *dailink = &atmel_asoc_wm8904_dailink;
+	struct clk *clk_src;
+	struct pinctrl *pinctrl;
+	int id, ret;
+
+	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
+	if (IS_ERR(pinctrl)) {
+		dev_err(&pdev->dev, "failed to request pinctrl\n");
+		return PTR_ERR(pinctrl);
+	}
+
+	card->dev = &pdev->dev;
+	ret = atmel_asoc_wm8904_dt_init(pdev);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to init dt info\n");
+		return ret;
+	}
+
+	id = of_alias_get_id((struct device_node *)dailink->cpu_of_node, "ssc");
+	ret = atmel_ssc_set_audio(id);
+	if (ret != 0) {
+		dev_err(&pdev->dev, "failed to set SSC %d for audio\n", id);
+		return ret;
+	}
+
+	mclk = clk_get(NULL, "pck0");
+	if (IS_ERR(mclk)) {
+		dev_err(&pdev->dev, "failed to get pck0\n");
+		ret = PTR_ERR(mclk);
+		goto err_set_audio;
+	}
+
+	clk_src = clk_get(NULL, "clk32k");
+	if (IS_ERR(clk_src)) {
+		dev_err(&pdev->dev, "failed to get clk32k\n");
+		ret = PTR_ERR(clk_src);
+		goto err_set_audio;
+	}
+
+	ret = clk_set_parent(mclk, clk_src);
+	clk_put(clk_src);
+	if (ret != 0) {
+		dev_err(&pdev->dev, "failed to set MCLK parent\n");
+		goto err_set_audio;
+	}
+
+	dev_info(&pdev->dev, "setting pck0 to %dHz\n", MCLK_RATE);
+	clk_set_rate(mclk, MCLK_RATE);
+
+	ret = snd_soc_register_card(card);
+	if (ret) {
+		dev_err(&pdev->dev, "snd_soc_register_card failed\n");
+		goto err_set_audio;
+	}
+
+	return 0;
+
+err_set_audio:
+	atmel_ssc_put_audio(id);
+	return ret;
+}
+
+static int atmel_asoc_wm8904_remove(struct platform_device *pdev)
+{
+	struct snd_soc_card *card = platform_get_drvdata(pdev);
+	struct snd_soc_dai_link *dailink = &atmel_asoc_wm8904_dailink;
+	int id;
+
+	id = of_alias_get_id((struct device_node *)dailink->cpu_of_node, "ssc");
+
+	snd_soc_unregister_card(card);
+	atmel_ssc_put_audio(id);
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id atmel_asoc_wm8904_dt_ids[] = {
+	{ .compatible = "atmel,asoc-wm8904", },
+	{ }
+};
+#endif
+
+static struct platform_driver atmel_asoc_wm8904_driver = {
+	.driver = {
+		.name = "atmel-wm8904-audio",
+		.owner = THIS_MODULE,
+		.of_match_table = of_match_ptr(atmel_asoc_wm8904_dt_ids),
+	},
+	.probe = atmel_asoc_wm8904_probe,
+	.remove = atmel_asoc_wm8904_remove,
+};
+
+module_platform_driver(atmel_asoc_wm8904_driver);
+
+/* Module information */
+MODULE_AUTHOR("Bo Shen <[e-mail]>");
+MODULE_DESCRIPTION("ALSA SoC machine driver for Atmel EK with WM8904 codec");
+MODULE_LICENSE("GPL");