Add IQAudIO Digi WM8804 board support

Support IQAudIO Digi board with iqaudio_digi machine driver and
 iqaudio-digi-wm8804-audio overlay.

NB. Machine driver is a cut and paste of hifiberry_digi code, with format
    and general cleanup to comply with kernel coding standards.

Signed-off-by: DigitalDreamtime <clive.messer@digitaldreamtime.co.uk>

sound/soc/bcm/Kconfig

@@ -81,6 +81,13 @@ config SND_BCM2708_SOC_IQAUDIO_DAC
 	help
 	  Say Y or M if you want to add support for IQaudIO-DAC.
 
+config SND_BCM2708_SOC_IQAUDIO_DIGI
+        tristate "Support for IQAudIO Digi"
+        depends on SND_BCM2708_SOC_I2S || SND_BCM2835_SOC_I2S
+        select SND_SOC_WM8804
+        help
+         Say Y or M if you want to add support for IQAudIO Digital IO board.
+
 config SND_BCM2708_SOC_ADAU1977_ADC
 	tristate "Support for ADAU1977 ADC"
 	depends on SND_BCM2708_SOC_I2S || SND_BCM2835_SOC_I2S

sound/soc/bcm/Makefile

@@ -19,6 +19,7 @@ snd-soc-justboom-digi-objs := justboom-digi.o
 snd-soc-rpi-dac-objs := rpi-dac.o
 snd-soc-rpi-proto-objs := rpi-proto.o
 snd-soc-iqaudio-dac-objs := iqaudio-dac.o
+snd-soc-iqaudio-digi-objs := iqaudio_digi.o
 snd-soc-audioinjector-pi-soundcard-objs := audioinjector-pi-soundcard.o
 
 obj-$(CONFIG_SND_BCM2708_SOC_ADAU1977_ADC) += snd-soc-adau1977-adc.o
@@ -31,4 +32,5 @@ obj-$(CONFIG_SND_BCM2708_SOC_JUSTBOOM_DIGI) += snd-soc-justboom-digi.o
 obj-$(CONFIG_SND_BCM2708_SOC_RPI_DAC) += snd-soc-rpi-dac.o
 obj-$(CONFIG_SND_BCM2708_SOC_RPI_PROTO) += snd-soc-rpi-proto.o
 obj-$(CONFIG_SND_BCM2708_SOC_IQAUDIO_DAC) += snd-soc-iqaudio-dac.o
+obj-$(CONFIG_SND_BCM2708_SOC_IQAUDIO_DIGI) += snd-soc-iqaudio-digi.o
 obj-$(CONFIG_SND_AUDIOINJECTOR_PI_SOUNDCARD) += snd-soc-audioinjector-pi-soundcard.o

sound/soc/bcm/iqaudio_digi.c

@@ -0,0 +1,239 @@
+/*
+ * ASoC Driver for IQAudIO WM8804 Digi
+ *
+ * Author: Daniel Matuschek <info@crazy-audio.com>
+ * based on the HifiBerry DAC driver by Florian Meier <florian.meier@koalo.de>
+ *	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.
+ *
+ * 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 <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include <sound/jack.h>
+
+#include "../codecs/wm8804.h"
+
+static short int auto_shutdown_output;
+module_param(auto_shutdown_output, short,
+	      S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
+MODULE_PARM_DESC(auto_shutdown_output, "Shutdown SP/DIF output if playback is stopped");
+
+static int snd_rpi_iqaudio_digi_init(struct snd_soc_pcm_runtime *rtd)
+{
+	struct snd_soc_codec *codec = rtd->codec;
+
+	/* enable TX output */
+	snd_soc_update_bits(codec, WM8804_PWRDN, 0x4, 0x0);
+
+	return 0;
+}
+
+static int snd_rpi_iqaudio_digi_startup(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_codec *codec = rtd->codec;
+
+	/* turn on digital output */
+	snd_soc_update_bits(codec, WM8804_PWRDN, 0x3c, 0x00);
+
+	return 0;
+}
+
+static void snd_rpi_iqaudio_digi_shutdown(struct snd_pcm_substream *substream)
+{
+	if (auto_shutdown_output) {
+		struct snd_soc_pcm_runtime *rtd = substream->private_data;
+		struct snd_soc_codec *codec = rtd->codec;
+
+		/* turn off digital output */
+		snd_soc_update_bits(codec, WM8804_PWRDN, 0x3c, 0x3c);
+	}
+}
+
+
+static int snd_rpi_iqaudio_digi_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;
+	struct snd_soc_codec *codec = rtd->codec;
+	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
+
+	int sysclk = 27000000; /* This is fixed on this board */
+
+	long mclk_freq = 0;
+	int mclk_div = 1;
+	int sampling_freq = 1;
+
+	int ret;
+
+	int samplerate = params_rate(params);
+
+	if (samplerate <= 96000) {
+		mclk_freq = samplerate * 256;
+		mclk_div = WM8804_MCLKDIV_256FS;
+	} else {
+		mclk_freq = samplerate * 128;
+		mclk_div = WM8804_MCLKDIV_128FS;
+	}
+
+	switch (samplerate) {
+	case 32000:
+		sampling_freq = 0x03;
+		break;
+	case 44100:
+		sampling_freq = 0x00;
+		break;
+	case 48000:
+		sampling_freq = 0x02;
+		break;
+	case 88200:
+		sampling_freq = 0x08;
+		break;
+	case 96000:
+		sampling_freq = 0x0a;
+		break;
+	case 176400:
+		sampling_freq = 0x0c;
+		break;
+	case 192000:
+		sampling_freq = 0x0e;
+		break;
+	default:
+		dev_err(codec->dev, "Failed to set WM8804 SYSCLK, unsupported samplerate %d\n",
+			samplerate);
+	}
+
+	snd_soc_dai_set_clkdiv(codec_dai, WM8804_MCLK_DIV, mclk_div);
+	snd_soc_dai_set_pll(codec_dai, 0, 0, sysclk, mclk_freq);
+
+	ret = snd_soc_dai_set_sysclk(codec_dai, WM8804_TX_CLKSRC_PLL,
+					sysclk, SND_SOC_CLOCK_OUT);
+	if (ret < 0) {
+		dev_err(codec->dev, "Failed to set WM8804 SYSCLK: %d\n", ret);
+		return ret;
+	}
+
+	/* Enable TX output */
+	snd_soc_update_bits(codec, WM8804_PWRDN, 0x4, 0x0);
+
+	/* Power on */
+	snd_soc_update_bits(codec, WM8804_PWRDN, 0x9, 0);
+
+	/* set sampling frequency status bits */
+	snd_soc_update_bits(codec, WM8804_SPDTX4, 0x0f, sampling_freq);
+
+	return snd_soc_dai_set_bclk_ratio(cpu_dai, 64);
+}
+
+/* machine stream operations */
+static struct snd_soc_ops snd_rpi_iqaudio_digi_ops = {
+	.hw_params	= snd_rpi_iqaudio_digi_hw_params,
+	.startup	= snd_rpi_iqaudio_digi_startup,
+	.shutdown	= snd_rpi_iqaudio_digi_shutdown,
+};
+
+static struct snd_soc_dai_link snd_rpi_iqaudio_digi_dai[] = {
+{
+	.name		= "IQAudIO Digi",
+	.stream_name	= "IQAudIO Digi HiFi",
+	.cpu_dai_name	= "bcm2708-i2s.0",
+	.codec_dai_name	= "wm8804-spdif",
+	.platform_name	= "bcm2708-i2s.0",
+	.codec_name	= "wm8804.1-003b",
+	.dai_fmt	= SND_SOC_DAIFMT_I2S |
+			  SND_SOC_DAIFMT_NB_NF |
+			  SND_SOC_DAIFMT_CBM_CFM,
+	.ops		= &snd_rpi_iqaudio_digi_ops,
+	.init		= snd_rpi_iqaudio_digi_init,
+},
+};
+
+/* audio machine driver */
+static struct snd_soc_card snd_rpi_iqaudio_digi = {
+	.name		= "IQAudIODigi",
+	.owner		= THIS_MODULE,
+	.dai_link	= snd_rpi_iqaudio_digi_dai,
+	.num_links	= ARRAY_SIZE(snd_rpi_iqaudio_digi_dai),
+};
+
+static int snd_rpi_iqaudio_digi_probe(struct platform_device *pdev)
+{
+	struct snd_soc_card *card = &snd_rpi_iqaudio_digi;
+	char *prefix = "wm8804-digi,";
+	char prop[128];
+	struct device_node *np;
+	int ret = 0;
+
+	snd_rpi_iqaudio_digi.dev = &pdev->dev;
+
+	np = pdev->dev.of_node;
+	if (np) {
+		struct snd_soc_dai_link *dai = &snd_rpi_iqaudio_digi_dai[0];
+		struct device_node *i2s_node;
+
+		i2s_node = of_parse_phandle(np, "i2s-controller", 0);
+		if (i2s_node) {
+			dai->cpu_dai_name = NULL;
+			dai->cpu_of_node = i2s_node;
+			dai->platform_name = NULL;
+			dai->platform_of_node = i2s_node;
+		}
+
+		snprintf(prop, sizeof(prop), "%scard-name", prefix);
+		of_property_read_string(np, prop, &card->name);
+
+		snprintf(prop, sizeof(prop), "%sdai-name", prefix);
+		of_property_read_string(np, prop, &dai->name);
+
+		snprintf(prop, sizeof(prop), "%sdai-stream-name", prefix);
+		of_property_read_string(np, prop, &dai->stream_name);
+	}
+
+	ret = snd_soc_register_card(card);
+	if (ret && ret != -EPROBE_DEFER)
+		dev_err(&pdev->dev, "snd_soc_register_card() failed: %d\n",
+			ret);
+
+	return ret;
+}
+
+static int snd_rpi_iqaudio_digi_remove(struct platform_device *pdev)
+{
+	return snd_soc_unregister_card(&snd_rpi_iqaudio_digi);
+}
+
+static const struct of_device_id snd_rpi_iqaudio_digi_of_match[] = {
+	{ .compatible = "iqaudio,wm8804-digi", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, snd_rpi_iqaudio_digi_of_match);
+
+static struct platform_driver snd_rpi_iqaudio_digi_driver = {
+	.driver = {
+		.name		= "IQAudIODigi",
+		.owner		= THIS_MODULE,
+		.of_match_table	= snd_rpi_iqaudio_digi_of_match,
+	},
+	.probe  = snd_rpi_iqaudio_digi_probe,
+	.remove = snd_rpi_iqaudio_digi_remove,
+};
+
+module_platform_driver(snd_rpi_iqaudio_digi_driver);
+
+MODULE_AUTHOR("Daniel Matuschek <info@crazy-audio.com>");
+MODULE_DESCRIPTION("ASoC Driver for IQAudIO WM8804 Digi");
+MODULE_LICENSE("GPL v2");