ASoC: Add codec driver for AK5386

Adds a driver for Asahi Kasei's AK5386 Single-ended 24-Bit 192kHz
delta-sigma ADC. The device has no control port interface but an
optional RESET/PDN GPIO pin.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 152 insertions, 0 deletions

diff --git a/sound/soc/codecs/ak5386.c b/sound/soc/codecs/ak5386.c
new file mode 100644
index 000000000000..1f303983ae02
--- /dev/null
+++ b/sound/soc/codecs/ak5386.c
@@ -0,0 +1,152 @@
+/*
+ * ALSA SoC driver for
+ *    Asahi Kasei AK5386 Single-ended 24-Bit 192kHz delta-sigma ADC
+ *
+ * (c) 2013 Daniel Mack <zonque@gmail.com>
+ *
+ * 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/slab.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/of_device.h>
+#include <sound/soc.h>
+#include <sound/pcm.h>
+#include <sound/initval.h>
+
+struct ak5386_priv {
+        int reset_gpio;
+};
+
+static struct snd_soc_codec_driver soc_codec_ak5386;
+
+static int ak5386_set_dai_fmt(struct snd_soc_dai *codec_dai,
+                              unsigned int format)
+{
+        struct snd_soc_codec *codec = codec_dai->codec;
+
+        format &= SND_SOC_DAIFMT_FORMAT_MASK;
+        if (format != SND_SOC_DAIFMT_LEFT_J &&
+            format != SND_SOC_DAIFMT_I2S) {
+                dev_err(codec->dev, "Invalid DAI format\n");
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+static int ak5386_hw_params(struct snd_pcm_substream *substream,
+                            struct snd_pcm_hw_params *params,
+                            struct snd_soc_dai *dai)
+{
+        struct snd_soc_codec *codec = dai->codec;
+        struct ak5386_priv *priv = snd_soc_codec_get_drvdata(codec);
+
+        /*
+         * From the datasheet:
+         *
+         * All external clocks (MCLK, SCLK and LRCK) must be present unless
+         * PDN pin = “L”. If these clocks are not provided, the AK5386 may
+         * draw excess current due to its use of internal dynamically
+         * refreshed logic. If the external clocks are not present, place
+         * the AK5386 in power-down mode (PDN pin = “L”).
+         */
+
+        if (gpio_is_valid(priv->reset_gpio))
+                gpio_set_value(priv->reset_gpio, 1);
+
+        return 0;
+}
+
+static int ak5386_hw_free(struct snd_pcm_substream *substream,
+                          struct snd_soc_dai *dai)
+{
+        struct snd_soc_codec *codec = dai->codec;
+        struct ak5386_priv *priv = snd_soc_codec_get_drvdata(codec);
+
+        if (gpio_is_valid(priv->reset_gpio))
+                gpio_set_value(priv->reset_gpio, 0);
+
+        return 0;
+}
+
+static const struct snd_soc_dai_ops ak5386_dai_ops = {
+        .set_fmt        = ak5386_set_dai_fmt,
+        .hw_params      = ak5386_hw_params,
+        .hw_free        = ak5386_hw_free,
+};
+
+static struct snd_soc_dai_driver ak5386_dai = {
+        .name           = "ak5386-hifi",
+        .capture        = {
+                .stream_name    = "Capture",
+                .channels_min   = 1,
+                .channels_max   = 2,
+                .rates          = SNDRV_PCM_RATE_8000_192000,
+                .formats        = SNDRV_PCM_FMTBIT_S8     |
+                                  SNDRV_PCM_FMTBIT_S16_LE |
+                                  SNDRV_PCM_FMTBIT_S24_LE |
+                                  SNDRV_PCM_FMTBIT_S24_3LE,
+        },
+        .ops    = &ak5386_dai_ops,
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id ak5386_dt_ids[] = {
+        { .compatible = "asahi-kasei,ak5386", },
+        { }
+};
+MODULE_DEVICE_TABLE(of, ak5386_dt_ids);
+#endif
+
+static int ak5386_probe(struct platform_device *pdev)
+{
+        struct device *dev = &pdev->dev;
+        struct ak5386_priv *priv;
+
+        priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+        if (!priv)
+                return -ENOMEM;
+
+        priv->reset_gpio = -EINVAL;
+        dev_set_drvdata(dev, priv);
+
+        if (of_match_device(of_match_ptr(ak5386_dt_ids), dev))
+                priv->reset_gpio = of_get_named_gpio(dev->of_node,
+                                                      "reset-gpio", 0);
+
+        if (gpio_is_valid(priv->reset_gpio))
+                if (devm_gpio_request_one(dev, priv->reset_gpio,
+                                          GPIOF_OUT_INIT_LOW,
+                                          "AK5386 Reset"))
+                        priv->reset_gpio = -EINVAL;
+
+        return snd_soc_register_codec(dev, &soc_codec_ak5386,
+                                      &ak5386_dai, 1);
+}
+
+static int ak5386_remove(struct platform_device *pdev)
+{
+        snd_soc_unregister_codec(&pdev->dev);
+        return 0;
+}
+
+static struct platform_driver ak5386_driver = {
+        .probe          = ak5386_probe,
+        .remove         = ak5386_remove,
+        .driver         = {
+                .name   = "ak5386",
+                .owner  = THIS_MODULE,
+                .of_match_table = of_match_ptr(ak5386_dt_ids),
+        },
+};
+
+module_platform_driver(ak5386_driver);
+
+MODULE_DESCRIPTION("ASoC driver for AK5386 ADC");
+MODULE_AUTHOR("Daniel Mack <zonque@gmail.com>");
+MODULE_LICENSE("GPL");