ASoC: Add support for HifiBerry DAC

This adds a machine driver for the HifiBerry DAC.
It is a sound card that can
be stacked onto the Raspberry Pi.

Signed-off-by: Florian Meier <florian.meier@koalo.de>

sound/soc/bcm/Kconfig

@@ -7,3 +7,10 @@ config SND_BCM2835_SOC_I2S
 	  Say Y or M if you want to add support for codecs attached to
 	  the BCM2835 I2S interface. You will also need
 	  to select the audio interfaces to support below.
+
+config SND_BCM2708_SOC_HIFIBERRY_DAC
+        tristate "Support for HifiBerry DAC"
+        depends on SND_BCM2708_SOC_I2S || SND_BCM2835_SOC_I2S
+        select SND_SOC_PCM5102A
+        help
+         Say Y or M if you want to add support for HifiBerry DAC.

sound/soc/bcm/Makefile

@@ -3,3 +3,7 @@ snd-soc-bcm2835-i2s-objs := bcm2835-i2s.o
 
 obj-$(CONFIG_SND_BCM2835_SOC_I2S) += snd-soc-bcm2835-i2s.o
 
+# BCM2708 Machine Support
+snd-soc-hifiberry-dac-objs := hifiberry_dac.o
+
+obj-$(CONFIG_SND_BCM2708_SOC_HIFIBERRY_DAC) += snd-soc-hifiberry-dac.o

sound/soc/bcm/hifiberry_dac.c

@@ -0,0 +1,122 @@
+/*
+ * ASoC Driver for HifiBerry DAC
+ *
+ * Author:	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>
+
+static int snd_rpi_hifiberry_dac_init(struct snd_soc_pcm_runtime *rtd)
+{
+	return 0;
+}
+
+static int snd_rpi_hifiberry_dac_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 *cpu_dai = rtd->cpu_dai;
+
+	unsigned int sample_bits =
+		snd_pcm_format_physical_width(params_format(params));
+
+	return snd_soc_dai_set_bclk_ratio(cpu_dai, sample_bits * 2);
+}
+
+/* machine stream operations */
+static struct snd_soc_ops snd_rpi_hifiberry_dac_ops = {
+	.hw_params = snd_rpi_hifiberry_dac_hw_params,
+};
+
+static struct snd_soc_dai_link snd_rpi_hifiberry_dac_dai[] = {
+{
+	.name		= "HifiBerry DAC",
+	.stream_name	= "HifiBerry DAC HiFi",
+	.cpu_dai_name	= "bcm2708-i2s.0",
+	.codec_dai_name	= "pcm5102a-hifi",
+	.platform_name	= "bcm2708-i2s.0",
+	.codec_name	= "pcm5102a-codec",
+	.dai_fmt	= SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_NB_NF |
+				SND_SOC_DAIFMT_CBS_CFS,
+	.ops		= &snd_rpi_hifiberry_dac_ops,
+	.init		= snd_rpi_hifiberry_dac_init,
+},
+};
+
+/* audio machine driver */
+static struct snd_soc_card snd_rpi_hifiberry_dac = {
+	.name         = "snd_rpi_hifiberry_dac",
+	.dai_link     = snd_rpi_hifiberry_dac_dai,
+	.num_links    = ARRAY_SIZE(snd_rpi_hifiberry_dac_dai),
+};
+
+static int snd_rpi_hifiberry_dac_probe(struct platform_device *pdev)
+{
+	int ret = 0;
+
+	snd_rpi_hifiberry_dac.dev = &pdev->dev;
+
+	if (pdev->dev.of_node) {
+	    struct device_node *i2s_node;
+	    struct snd_soc_dai_link *dai = &snd_rpi_hifiberry_dac_dai[0];
+	    i2s_node = of_parse_phandle(pdev->dev.of_node,
+					"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;
+	    }
+	}
+
+	ret = snd_soc_register_card(&snd_rpi_hifiberry_dac);
+	if (ret)
+		dev_err(&pdev->dev, "snd_soc_register_card() failed: %d\n", ret);
+
+	return ret;
+}
+
+static int snd_rpi_hifiberry_dac_remove(struct platform_device *pdev)
+{
+	return snd_soc_unregister_card(&snd_rpi_hifiberry_dac);
+}
+
+static const struct of_device_id snd_rpi_hifiberry_dac_of_match[] = {
+	{ .compatible = "hifiberry,hifiberry-dac", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, snd_rpi_hifiberry_dac_of_match);
+
+static struct platform_driver snd_rpi_hifiberry_dac_driver = {
+        .driver = {
+                .name   = "snd-hifiberry-dac",
+                .owner  = THIS_MODULE,
+		.of_match_table = snd_rpi_hifiberry_dac_of_match,
+        },
+        .probe          = snd_rpi_hifiberry_dac_probe,
+        .remove         = snd_rpi_hifiberry_dac_remove,
+};
+
+module_platform_driver(snd_rpi_hifiberry_dac_driver);
+
+MODULE_AUTHOR("Florian Meier <florian.meier@koalo.de>");
+MODULE_DESCRIPTION("ASoC Driver for HifiBerry DAC");
+MODULE_LICENSE("GPL v2");