ALSA: ASoC: Add SPI support for WM8731

[Modified to allow runtime selection between I2C and SPI and to select
SPI_MASTER for all codecs build so this is included. -- broonie]

Signed-off-by: Cliff Cai <cliff.cai@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

3 files changed, 71 insertions, 2 deletions

diff --git a/sound/soc/codecs/Kconfig b/sound/soc/codecs/Kconfig
index 13ae4fd2d179..cceac73aff0a 100644
--- a/sound/soc/codecs/Kconfig
+++ b/sound/soc/codecs/Kconfig
@@ -2,6 +2,7 @@ config SND_SOC_ALL_CODECS
         tristate "Build all ASoC CODEC drivers"
         depends on I2C
         select SPI
+        select SPI_MASTER
         select SND_SOC_AK4535
         select SND_SOC_UDA1380
         select SND_SOC_WM8510
diff --git a/sound/soc/codecs/wm8731.c b/sound/soc/codecs/wm8731.c
index 5814f9bdf0c0..975befdfd885 100644
--- a/sound/soc/codecs/wm8731.c
+++ b/sound/soc/codecs/wm8731.c
@@ -19,6 +19,7 @@
 #include <linux/pm.h>
 #include <linux/i2c.h>
 #include <linux/platform_device.h>
+#include <linux/spi/spi.h>
 #include <sound/core.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
@@ -652,6 +653,61 @@ err_driver:
 }
 #endif
 
+#if defined(CONFIG_SPI_MASTER)
+static int __devinit wm8731_spi_probe(struct spi_device *spi)
+{
+        struct snd_soc_device *socdev = wm8731_socdev;
+        struct snd_soc_codec *codec = socdev->codec;
+        int ret;
+
+        codec->control_data = spi;
+
+        ret = wm8731_init(socdev);
+        if (ret < 0)
+                dev_err(&spi->dev, "failed to initialise WM8731\n");
+
+        return ret;
+}
+
+static int __devexit wm8731_spi_remove(struct spi_device *spi)
+{
+        return 0;
+}
+
+static struct spi_driver wm8731_spi_driver = {
+        .driver = {
+                .name   = "wm8731",
+                .bus    = &spi_bus_type,
+                .owner  = THIS_MODULE,
+        },
+        .probe          = wm8731_spi_probe,
+        .remove         = __devexit_p(wm8731_spi_remove),
+};
+
+static int wm8731_spi_write(struct spi_device *spi, const char *data, int len)
+{
+        struct spi_transfer t;
+        struct spi_message m;
+        u16 msg[2];
+
+        if (len <= 0)
+                return 0;
+
+        msg[0] = (data[0] << 8) + data[1];
+
+        spi_message_init(&m);
+        memset(&t, 0, (sizeof t));
+
+        t.tx_buf = &msg[0];
+        t.len = len;
+
+        spi_message_add_tail(&t, &m);
+        spi_sync(spi, &m);
+
+        return len;
+}
+#endif /* CONFIG_SPI_MASTER */
+
 static int wm8731_probe(struct platform_device *pdev)
 {
         struct snd_soc_device *socdev = platform_get_drvdata(pdev);
@@ -680,13 +736,21 @@ static int wm8731_probe(struct platform_device *pdev)
         INIT_LIST_HEAD(&codec->dapm_paths);
 
         wm8731_socdev = socdev;
+        ret = -ENODEV;
+
 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
         if (setup->i2c_address) {
                 codec->hw_write = (hw_write_t)i2c_master_send;
                 ret = wm8731_add_i2c_device(pdev, setup);
         }
-#else
-        /* Add other interfaces here */
+#endif
+#if defined(CONFIG_SPI_MASTER)
+        if (setup->spi) {
+                codec->hw_write = (hw_write_t)wm8731_spi_write;
+                ret = spi_register_driver(&wm8731_spi_driver);
+                if (ret != 0)
+                        printk(KERN_ERR "can't add spi driver");
+        }
 #endif
 
         if (ret != 0) {
@@ -711,6 +775,9 @@ static int wm8731_remove(struct platform_device *pdev)
         i2c_unregister_device(codec->control_data);
         i2c_del_driver(&wm8731_i2c_driver);
 #endif
+#if defined(CONFIG_SPI_MASTER)
+        spi_unregister_driver(&wm8731_spi_driver);
+#endif
         kfree(codec->private_data);
         kfree(codec);
 
diff --git a/sound/soc/codecs/wm8731.h b/sound/soc/codecs/wm8731.h
index 0f8123909ab0..95190e9c0c14 100644
--- a/sound/soc/codecs/wm8731.h
+++ b/sound/soc/codecs/wm8731.h
@@ -35,6 +35,7 @@
 #define WM8731_DAI              0
 
 struct wm8731_setup_data {
+        int            spi;
         int            i2c_bus;
         unsigned short i2c_address;
 };