ASoC: Add a driver for AK4104 S/PDIF transmitter

This adds a driver for the SPI connected AK4104 S/PDIF transmitter
device. Its features are fairly simple, but as there is need to set up
certain bits in the IEC958 information, this better goes into a real
driver.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Mark Brown <broonie@sirena.org.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

4 files changed, 376 insertions, 0 deletions

diff --git a/sound/soc/codecs/Kconfig b/sound/soc/codecs/Kconfig
index 628a591c728f..a1af311e7f06 100644
--- a/sound/soc/codecs/Kconfig
+++ b/sound/soc/codecs/Kconfig
@@ -14,6 +14,7 @@ config SND_SOC_ALL_CODECS
         select SND_SOC_AC97_CODEC if SND_SOC_AC97_BUS
         select SND_SOC_AD1980 if SND_SOC_AC97_BUS
         select SND_SOC_AD73311 if I2C
+        select SND_SOC_AK4104 if SPI_MASTER
         select SND_SOC_AK4535 if I2C
         select SND_SOC_CS4270 if I2C
         select SND_SOC_PCM3008
@@ -60,6 +61,9 @@ config SND_SOC_AD1980
 config SND_SOC_AD73311
         tristate
 
+config SND_SOC_AK4104
+        tristate
+
 config SND_SOC_AK4535
         tristate
 
diff --git a/sound/soc/codecs/Makefile b/sound/soc/codecs/Makefile
index 3664cdc300b2..4717c3c99040 100644
--- a/sound/soc/codecs/Makefile
+++ b/sound/soc/codecs/Makefile
@@ -1,6 +1,7 @@
 snd-soc-ac97-objs := ac97.o
 snd-soc-ad1980-objs := ad1980.o
 snd-soc-ad73311-objs := ad73311.o
+snd-soc-ak4104-objs := ak4104.o
 snd-soc-ak4535-objs := ak4535.o
 snd-soc-cs4270-objs := cs4270.o
 snd-soc-l3-objs := l3.o
@@ -30,6 +31,7 @@ snd-soc-wm9713-objs := wm9713.o
 obj-$(CONFIG_SND_SOC_AC97_CODEC)        += snd-soc-ac97.o
 obj-$(CONFIG_SND_SOC_AD1980)    += snd-soc-ad1980.o
 obj-$(CONFIG_SND_SOC_AD73311) += snd-soc-ad73311.o
+obj-$(CONFIG_SND_SOC_AK4104)    += snd-soc-ak4104.o
 obj-$(CONFIG_SND_SOC_AK4535)    += snd-soc-ak4535.o
 obj-$(CONFIG_SND_SOC_CS4270)    += snd-soc-cs4270.o
 obj-$(CONFIG_SND_SOC_L3)        += snd-soc-l3.o
diff --git a/sound/soc/codecs/ak4104.c b/sound/soc/codecs/ak4104.c
new file mode 100644
index 000000000000..338381f4fe1e
--- /dev/null
+++ b/sound/soc/codecs/ak4104.c
@@ -0,0 +1,363 @@
+/*
+ * AK4104 ALSA SoC (ASoC) driver
+ *
+ * Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
+ *
+ *  This program is free software; you can redistribute  it and/or modify it
+ *  under the terms of  the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the  License, or (at your
+ *  option) any later version.
+ */
+
+#include <linux/module.h>
+#include <sound/core.h>
+#include <sound/soc.h>
+#include <sound/initval.h>
+#include <linux/spi/spi.h>
+#include <sound/asoundef.h>
+
+#include "ak4104.h"
+
+/* AK4104 registers addresses */
+#define AK4104_REG_CONTROL1             0x00
+#define AK4104_REG_RESERVED             0x01
+#define AK4104_REG_CONTROL2             0x02
+#define AK4104_REG_TX                   0x03
+#define AK4104_REG_CHN_STATUS(x)        ((x) + 0x04)
+#define AK4104_NUM_REGS                 10
+
+#define AK4104_REG_MASK                 0x1f
+#define AK4104_READ                     0xc0
+#define AK4104_WRITE                    0xe0
+#define AK4104_RESERVED_VAL             0x5b
+
+/* Bit masks for AK4104 registers */
+#define AK4104_CONTROL1_RSTN            (1 << 0)
+#define AK4104_CONTROL1_PW              (1 << 1)
+#define AK4104_CONTROL1_DIF0            (1 << 2)
+#define AK4104_CONTROL1_DIF1            (1 << 3)
+
+#define AK4104_CONTROL2_SEL0            (1 << 0)
+#define AK4104_CONTROL2_SEL1            (1 << 1)
+#define AK4104_CONTROL2_MODE            (1 << 2)
+
+#define AK4104_TX_TXE                   (1 << 0)
+#define AK4104_TX_V                     (1 << 1)
+
+#define DRV_NAME "ak4104"
+
+struct ak4104_private {
+        struct snd_soc_codec codec;
+        u8 reg_cache[AK4104_NUM_REGS];
+};
+
+static int ak4104_fill_cache(struct snd_soc_codec *codec)
+{
+        int i;
+        u8 *reg_cache = codec->reg_cache;
+        struct spi_device *spi = codec->control_data;
+
+        for (i = 0; i < codec->reg_cache_size; i++) {
+                int ret = spi_w8r8(spi, i | AK4104_READ);
+                if (ret < 0) {
+                        dev_err(&spi->dev, "SPI write failure\n");
+                        return ret;
+                }
+
+                reg_cache[i] = ret;
+        }
+
+        return 0;
+}
+
+static unsigned int ak4104_read_reg_cache(struct snd_soc_codec *codec,
+                                          unsigned int reg)
+{
+        u8 *reg_cache = codec->reg_cache;
+
+        if (reg >= codec->reg_cache_size)
+                return -EINVAL;
+
+        return reg_cache[reg];
+}
+
+static int ak4104_spi_write(struct snd_soc_codec *codec, unsigned int reg,
+                            unsigned int value)
+{
+        u8 *cache = codec->reg_cache;
+        struct spi_device *spi = codec->control_data;
+
+        if (reg >= codec->reg_cache_size)
+                return -EINVAL;
+
+        reg &= AK4104_REG_MASK;
+        reg |= AK4104_WRITE;
+
+        /* only write to the hardware if value has changed */
+        if (cache[reg] != value) {
+                u8 tmp[2] = { reg, value };
+                if (spi_write(spi, tmp, sizeof(tmp))) {
+                        dev_err(&spi->dev, "SPI write failed\n");
+                        return -EIO;
+                }
+
+                cache[reg] = value;
+        }
+
+        return 0;
+}
+
+static int ak4104_set_dai_fmt(struct snd_soc_dai *codec_dai,
+                              unsigned int format)
+{
+        struct snd_soc_codec *codec = codec_dai->codec;
+        int val = 0;
+
+        val = ak4104_read_reg_cache(codec, AK4104_REG_CONTROL1);
+        if (val < 0)
+                return val;
+
+        val &= ~(AK4104_CONTROL1_DIF0 | AK4104_CONTROL1_DIF1);
+
+        /* set DAI format */
+        switch (format & SND_SOC_DAIFMT_FORMAT_MASK) {
+        case SND_SOC_DAIFMT_RIGHT_J:
+                break;
+        case SND_SOC_DAIFMT_LEFT_J:
+                val |= AK4104_CONTROL1_DIF0;
+                break;
+        case SND_SOC_DAIFMT_I2S:
+                val |= AK4104_CONTROL1_DIF0 | AK4104_CONTROL1_DIF1;
+                break;
+        default:
+                dev_err(codec->dev, "invalid dai format\n");
+                return -EINVAL;
+        }
+
+        /* This device can only be slave */
+        if ((format & SND_SOC_DAIFMT_MASTER_MASK) != SND_SOC_DAIFMT_CBS_CFS)
+                return -EINVAL;
+
+        return ak4104_spi_write(codec, AK4104_REG_CONTROL1, val);
+}
+
+static int ak4104_hw_params(struct snd_pcm_substream *substream,
+                            struct snd_pcm_hw_params *params,
+                            struct snd_soc_dai *dai)
+{
+        struct snd_soc_pcm_runtime *rtd = substream->private_data;
+        struct snd_soc_device *socdev = rtd->socdev;
+        struct snd_soc_codec *codec = socdev->card->codec;
+        int val = 0;
+
+        /* set the IEC958 bits: consumer mode, no copyright bit */
+        val |= IEC958_AES0_CON_NOT_COPYRIGHT;
+        ak4104_spi_write(codec, AK4104_REG_CHN_STATUS(0), val);
+
+        val = 0;
+
+        switch (params_rate(params)) {
+        case 44100:
+                val |= IEC958_AES3_CON_FS_44100;
+                break;
+        case 48000:
+                val |= IEC958_AES3_CON_FS_48000;
+                break;
+        case 32000:
+                val |= IEC958_AES3_CON_FS_32000;
+                break;
+        default:
+                dev_err(codec->dev, "unsupported sampling rate\n");
+                return -EINVAL;
+        }
+
+        return ak4104_spi_write(codec, AK4104_REG_CHN_STATUS(3), val);
+}
+
+struct snd_soc_dai ak4104_dai = {
+        .name = DRV_NAME,
+        .playback = {
+                .stream_name = "Playback",
+                .channels_min = 2,
+                .channels_max = 2,
+                .rates = SNDRV_PCM_RATE_44100 |
+                         SNDRV_PCM_RATE_48000 |
+                         SNDRV_PCM_RATE_32000,
+                .formats = SNDRV_PCM_FMTBIT_S16_LE  |
+                           SNDRV_PCM_FMTBIT_S24_3LE |
+                           SNDRV_PCM_FMTBIT_S24_LE
+        },
+        .ops = {
+                .hw_params = ak4104_hw_params,
+                .set_fmt = ak4104_set_dai_fmt,
+        }
+};
+
+static struct snd_soc_codec *ak4104_codec;
+
+static int ak4104_spi_probe(struct spi_device *spi)
+{
+        struct snd_soc_codec *codec;
+        struct ak4104_private *ak4104;
+        int ret, val;
+
+        spi->bits_per_word = 8;
+        spi->mode = SPI_MODE_0;
+        ret = spi_setup(spi);
+        if (ret < 0)
+                return ret;
+
+        ak4104 = kzalloc(sizeof(struct ak4104_private), GFP_KERNEL);
+        if (!ak4104) {
+                dev_err(&spi->dev, "could not allocate codec\n");
+                return -ENOMEM;
+        }
+
+        codec = &ak4104->codec;
+        mutex_init(&codec->mutex);
+        INIT_LIST_HEAD(&codec->dapm_widgets);
+        INIT_LIST_HEAD(&codec->dapm_paths);
+
+        codec->dev = &spi->dev;
+        codec->name = DRV_NAME;
+        codec->owner = THIS_MODULE;
+        codec->dai = &ak4104_dai;
+        codec->num_dai = 1;
+        codec->private_data = ak4104;
+        codec->control_data = spi;
+        codec->reg_cache = ak4104->reg_cache;
+        codec->reg_cache_size = AK4104_NUM_REGS;
+
+        /* read all regs and fill the cache */
+        ret = ak4104_fill_cache(codec);
+        if (ret < 0) {
+                dev_err(&spi->dev, "failed to fill register cache\n");
+                return ret;
+        }
+
+        /* read the 'reserved' register - according to the datasheet, it
+         * should contain 0x5b. Not a good way to verify the presence of
+         * the device, but there is no hardware ID register. */
+        if (ak4104_read_reg_cache(codec, AK4104_REG_RESERVED) !=
+                                         AK4104_RESERVED_VAL) {
+                ret = -ENODEV;
+                goto error_free_codec;
+        }
+
+        /* set power-up and non-reset bits */
+        val = ak4104_read_reg_cache(codec, AK4104_REG_CONTROL1);
+        val |= AK4104_CONTROL1_PW | AK4104_CONTROL1_RSTN;
+        ret = ak4104_spi_write(codec, AK4104_REG_CONTROL1, val);
+        if (ret < 0)
+                goto error_free_codec;
+
+        /* enable transmitter */
+        val = ak4104_read_reg_cache(codec, AK4104_REG_TX);
+        val |= AK4104_TX_TXE;
+        ret = ak4104_spi_write(codec, AK4104_REG_TX, val);
+        if (ret < 0)
+                goto error_free_codec;
+
+        ak4104_codec = codec;
+        ret = snd_soc_register_dai(&ak4104_dai);
+        if (ret < 0) {
+                dev_err(&spi->dev, "failed to register DAI\n");
+                goto error_free_codec;
+        }
+
+        spi_set_drvdata(spi, ak4104);
+        dev_info(&spi->dev, "SPI device initialized\n");
+        return 0;
+
+error_free_codec:
+        kfree(ak4104);
+        ak4104_dai.dev = NULL;
+        return ret;
+}
+
+static int __devexit ak4104_spi_remove(struct spi_device *spi)
+{
+        int ret, val;
+        struct ak4104_private *ak4104 = spi_get_drvdata(spi);
+
+        val = ak4104_read_reg_cache(&ak4104->codec, AK4104_REG_CONTROL1);
+        if (val < 0)
+                return val;
+
+        /* clear power-up and non-reset bits */
+        val &= ~(AK4104_CONTROL1_PW | AK4104_CONTROL1_RSTN);
+        ret = ak4104_spi_write(&ak4104->codec, AK4104_REG_CONTROL1, val);
+        if (ret < 0)
+                return ret;
+
+        ak4104_codec = NULL;
+        kfree(ak4104);
+        return 0;
+}
+
+static int ak4104_probe(struct platform_device *pdev)
+{
+        struct snd_soc_device *socdev = platform_get_drvdata(pdev);
+        struct snd_soc_codec *codec = ak4104_codec;
+        int ret;
+
+        /* Connect the codec to the socdev.  snd_soc_new_pcms() needs this. */
+        socdev->card->codec = codec;
+
+        /* Register PCMs */
+        ret = snd_soc_new_pcms(socdev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1);
+        if (ret < 0) {
+                dev_err(codec->dev, "failed to create pcms\n");
+                return ret;
+        }
+
+        /* Register the socdev */
+        ret = snd_soc_init_card(socdev);
+        if (ret < 0) {
+                dev_err(codec->dev, "failed to register card\n");
+                snd_soc_free_pcms(socdev);
+                return ret;
+        }
+
+        return 0;
+}
+
+static int ak4104_remove(struct platform_device *pdev)
+{
+        struct snd_soc_device *socdev = platform_get_drvdata(pdev);
+        snd_soc_free_pcms(socdev);
+        return 0;
+};
+
+struct snd_soc_codec_device soc_codec_device_ak4104 = {
+        .probe =        ak4104_probe,
+        .remove =       ak4104_remove
+};
+EXPORT_SYMBOL_GPL(soc_codec_device_ak4104);
+
+static struct spi_driver ak4104_spi_driver = {
+        .driver  = {
+                .name   = DRV_NAME,
+                .owner  = THIS_MODULE,
+        },
+        .probe  = ak4104_spi_probe,
+        .remove = __devexit_p(ak4104_spi_remove),
+};
+
+static int __init ak4104_init(void)
+{
+        pr_info("Asahi Kasei AK4104 ALSA SoC Codec Driver\n");
+        return spi_register_driver(&ak4104_spi_driver);
+}
+module_init(ak4104_init);
+
+static void __exit ak4104_exit(void)
+{
+        spi_unregister_driver(&ak4104_spi_driver);
+}
+module_exit(ak4104_exit);
+
+MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
+MODULE_DESCRIPTION("Asahi Kasei AK4104 ALSA SoC driver");
+MODULE_LICENSE("GPL");
+
diff --git a/sound/soc/codecs/ak4104.h b/sound/soc/codecs/ak4104.h
new file mode 100644
index 000000000000..eb88fe7e4def
--- /dev/null
+++ b/sound/soc/codecs/ak4104.h
@@ -0,0 +1,7 @@
+#ifndef _AK4104_H
+#define _AK4104_H
+
+extern struct snd_soc_dai ak4104_dai;
+extern struct snd_soc_codec_device soc_codec_device_ak4104;
+
+#endif