ASoC: Add driver for PROTO Audio CODEC (with a WM8731)

Add support for the MikroElektronika PROTO audio codec board.

URL to the audio chip:
http://www.mikroe.com/add-on-boards/audio-voice/audio-codec-proto/

Signed-off-by: Florian Meier <[e-mail]>
Signed-off-by: Codrin Ciubotariu <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

sound/soc/atmel/Kconfig

···
 	help
 	  Say Y or M if you want to add support for Atmel ASoc driver for boards
 	  using I2S.
+
+config SND_SOC_MIKROE_PROTO
+	tristate "Support for Mikroe-PROTO board"
+	depends on OF
+	select SND_SOC_WM8731
+	help
+	  Say Y or M if you want to add support for MikroElektronika PROTO Audio
+	  Board. This board contains the WM8731 codec, which can be configured
+	  using I2C over SDA (MPU Data Input) and SCL (MPU Clock Input) pins.
+	  Both playback and capture are supported.
+
 endif

sound/soc/atmel/Makefile

···
 snd-atmel-soc-classd-objs := atmel-classd.o
 snd-atmel-soc-pdmic-objs := atmel-pdmic.o
 snd-atmel-soc-tse850-pcm5142-objs := tse850-pcm5142.o
+snd-soc-mikroe-proto-objs := mikroe-proto.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-$(CONFIG_SND_ATMEL_SOC_CLASSD) += snd-atmel-soc-classd.o
 obj-$(CONFIG_SND_ATMEL_SOC_PDMIC) += snd-atmel-soc-pdmic.o
 obj-$(CONFIG_SND_ATMEL_SOC_TSE850_PCM5142) += snd-atmel-soc-tse850-pcm5142.o
+obj-$(CONFIG_SND_SOC_MIKROE_PROTO) += snd-soc-mikroe-proto.o

sound/soc/atmel/mikroe-proto.c

···
+/*
+ * ASoC driver for PROTO AudioCODEC (with a WM8731)
+ *
+ * Author:      Florian Meier, <[e-mail]>
+ *	      Copyright 2013
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/soc.h>
+#include <sound/jack.h>
+
+#include "../codecs/wm8731.h"
+
+#define XTAL_RATE 12288000	/* This is fixed on this board */
+
+static int snd_proto_init(struct snd_soc_pcm_runtime *rtd)
+{
+	struct snd_soc_card *card = rtd->card;
+	struct snd_soc_dai *codec_dai = rtd->codec_dai;
+
+	/* Set proto sysclk */
+	int ret = snd_soc_dai_set_sysclk(codec_dai, WM8731_SYSCLK_XTAL,
+					 XTAL_RATE, SND_SOC_CLOCK_IN);
+	if (ret < 0) {
+		dev_err(card->dev, "Failed to set WM8731 SYSCLK: %d\n",
+			ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct snd_soc_dapm_widget snd_proto_widget[] = {
+	SND_SOC_DAPM_MIC("Microphone Jack", NULL),
+	SND_SOC_DAPM_HP("Headphone Jack", NULL),
+};
+
+static const struct snd_soc_dapm_route snd_proto_route[] = {
+	/* speaker connected to LHPOUT/RHPOUT */
+	{"Headphone Jack", NULL, "LHPOUT"},
+	{"Headphone Jack", NULL, "RHPOUT"},
+
+	/* mic is connected to Mic Jack, with WM8731 Mic Bias */
+	{"MICIN", NULL, "Mic Bias"},
+	{"Mic Bias", NULL, "Microphone Jack"},
+};
+
+/* audio machine driver */
+static struct snd_soc_card snd_proto = {
+	.name		= "snd_mikroe_proto",
+	.owner		= THIS_MODULE,
+	.dapm_widgets	= snd_proto_widget,
+	.num_dapm_widgets = ARRAY_SIZE(snd_proto_widget),
+	.dapm_routes	= snd_proto_route,
+	.num_dapm_routes = ARRAY_SIZE(snd_proto_route),
+};
+
+static int snd_proto_probe(struct platform_device *pdev)
+{
+	struct snd_soc_dai_link *dai;
+	struct device_node *np = pdev->dev.of_node;
+	struct device_node *codec_np, *cpu_np;
+	struct device_node *bitclkmaster = NULL;
+	struct device_node *framemaster = NULL;
+	unsigned int dai_fmt;
+	int ret = 0;
+
+	if (!np) {
+		dev_err(&pdev->dev, "No device node supplied\n");
+		return -EINVAL;
+	}
+
+	snd_proto.dev = &pdev->dev;
+	ret = snd_soc_of_parse_card_name(&snd_proto, "model");
+	if (ret)
+		return ret;
+
+	dai = devm_kzalloc(&pdev->dev, sizeof(*dai), GFP_KERNEL);
+	if (!dai)
+		return -ENOMEM;
+
+	snd_proto.dai_link = dai;
+	snd_proto.num_links = 1;
+
+	dai->name = "WM8731";
+	dai->stream_name = "WM8731 HiFi";
+	dai->codec_dai_name = "wm8731-hifi";
+	dai->init = &snd_proto_init;
+
+	codec_np = of_parse_phandle(np, "audio-codec", 0);
+	if (!codec_np) {
+		dev_err(&pdev->dev, "audio-codec node missing\n");
+		return -EINVAL;
+	}
+	dai->codec_of_node = codec_np;
+
+	cpu_np = of_parse_phandle(np, "i2s-controller", 0);
+	if (!cpu_np) {
+		dev_err(&pdev->dev, "i2s-controller missing\n");
+		return -EINVAL;
+	}
+	dai->cpu_of_node = cpu_np;
+	dai->platform_of_node = cpu_np;
+
+	dai_fmt = snd_soc_of_parse_daifmt(np, NULL,
+					  &bitclkmaster, &framemaster);
+	if (bitclkmaster != framemaster) {
+		dev_err(&pdev->dev, "Must be the same bitclock and frame master\n");
+		return -EINVAL;
+	}
+	if (bitclkmaster) {
+		dai_fmt &= ~SND_SOC_DAIFMT_MASTER_MASK;
+		if (codec_np == bitclkmaster)
+			dai_fmt |= SND_SOC_DAIFMT_CBM_CFM;
+		else
+			dai_fmt |= SND_SOC_DAIFMT_CBS_CFS;
+	}
+	of_node_put(bitclkmaster);
+	of_node_put(framemaster);
+	dai->dai_fmt = dai_fmt;
+
+	of_node_put(codec_np);
+	of_node_put(cpu_np);
+
+	ret = snd_soc_register_card(&snd_proto);
+	if (ret && ret != -EPROBE_DEFER)
+		dev_err(&pdev->dev,
+			"snd_soc_register_card() failed: %d\n", ret);
+
+	return ret;
+}
+
+static int snd_proto_remove(struct platform_device *pdev)
+{
+	return snd_soc_unregister_card(&snd_proto);
+}
+
+static const struct of_device_id snd_proto_of_match[] = {
+	{ .compatible = "mikroe,mikroe-proto", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, snd_proto_of_match);
+
+static struct platform_driver snd_proto_driver = {
+	.driver = {
+		.name   = "snd-mikroe-proto",
+		.of_match_table = snd_proto_of_match,
+	},
+	.probe	  = snd_proto_probe,
+	.remove	 = snd_proto_remove,
+};
+
+module_platform_driver(snd_proto_driver);
+
+MODULE_AUTHOR("Florian Meier");
+MODULE_DESCRIPTION("ASoC Driver for PROTO board (WM8731)");
+MODULE_LICENSE("GPL");