Merge tag 'asoc-ac97-gpio' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into devel

ASoC: Add a GPIO chip for AC'97

GPIOs are part of the AC'97 spec, enable their use on embedded platforms
using AC'97.

1 files changed, 125 insertions, 0 deletions

diff --git a/sound/soc/soc-ac97.c b/sound/soc/soc-ac97.c
index d40efc9fe0a9..ae563e379a72 100644
--- a/sound/soc/soc-ac97.c
+++ b/sound/soc/soc-ac97.c
@@ -20,6 +20,7 @@
 #include <linux/delay.h>
 #include <linux/export.h>
 #include <linux/gpio.h>
+#include <linux/gpio/driver.h>
 #include <linux/init.h>
 #include <linux/of_gpio.h>
 #include <linux/of.h>
@@ -38,6 +39,14 @@ struct snd_ac97_reset_cfg {
         int gpio_reset;
 };
 
+struct snd_ac97_gpio_priv {
+#ifdef CONFIG_GPIOLIB
+        struct gpio_chip gpio_chip;
+#endif
+        unsigned int gpios_set;
+        struct snd_soc_codec *codec;
+};
+
 static struct snd_ac97_bus soc_ac97_bus = {
         .ops = NULL, /* Gets initialized in snd_soc_set_ac97_ops() */
 };
@@ -47,6 +56,117 @@ static void soc_ac97_device_release(struct device *dev)
         kfree(to_ac97_t(dev));
 }
 
+#ifdef CONFIG_GPIOLIB
+static inline struct snd_soc_codec *gpio_to_codec(struct gpio_chip *chip)
+{
+        struct snd_ac97_gpio_priv *gpio_priv =
+                container_of(chip, struct snd_ac97_gpio_priv, gpio_chip);
+
+        return gpio_priv->codec;
+}
+
+static int snd_soc_ac97_gpio_request(struct gpio_chip *chip, unsigned offset)
+{
+        if (offset >= AC97_NUM_GPIOS)
+                return -EINVAL;
+
+        return 0;
+}
+
+static int snd_soc_ac97_gpio_direction_in(struct gpio_chip *chip,
+                                          unsigned offset)
+{
+        struct snd_soc_codec *codec = gpio_to_codec(chip);
+
+        dev_dbg(codec->dev, "set gpio %d to output\n", offset);
+        return snd_soc_update_bits(codec, AC97_GPIO_CFG,
+                                   1 << offset, 1 << offset);
+}
+
+static int snd_soc_ac97_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+        struct snd_soc_codec *codec = gpio_to_codec(chip);
+        int ret;
+
+        ret = snd_soc_read(codec, AC97_GPIO_STATUS);
+        dev_dbg(codec->dev, "get gpio %d : %d\n", offset,
+                ret < 0 ? ret : ret & (1 << offset));
+
+        return ret < 0 ? ret : ret & (1 << offset);
+}
+
+static void snd_soc_ac97_gpio_set(struct gpio_chip *chip, unsigned offset,
+                                  int value)
+{
+        struct snd_ac97_gpio_priv *gpio_priv =
+                container_of(chip, struct snd_ac97_gpio_priv, gpio_chip);
+        struct snd_soc_codec *codec = gpio_to_codec(chip);
+
+        gpio_priv->gpios_set &= ~(1 << offset);
+        gpio_priv->gpios_set |= (!!value) << offset;
+        snd_soc_write(codec, AC97_GPIO_STATUS, gpio_priv->gpios_set);
+        dev_dbg(codec->dev, "set gpio %d to %d\n", offset, !!value);
+}
+
+static int snd_soc_ac97_gpio_direction_out(struct gpio_chip *chip,
+                                     unsigned offset, int value)
+{
+        struct snd_soc_codec *codec = gpio_to_codec(chip);
+
+        dev_dbg(codec->dev, "set gpio %d to output\n", offset);
+        snd_soc_ac97_gpio_set(chip, offset, value);
+        return snd_soc_update_bits(codec, AC97_GPIO_CFG, 1 << offset, 0);
+}
+
+static struct gpio_chip snd_soc_ac97_gpio_chip = {
+        .label                  = "snd_soc_ac97",
+        .owner                  = THIS_MODULE,
+        .request                = snd_soc_ac97_gpio_request,
+        .direction_input        = snd_soc_ac97_gpio_direction_in,
+        .get                    = snd_soc_ac97_gpio_get,
+        .direction_output       = snd_soc_ac97_gpio_direction_out,
+        .set                    = snd_soc_ac97_gpio_set,
+        .can_sleep              = 1,
+};
+
+static int snd_soc_ac97_init_gpio(struct snd_ac97 *ac97,
+                                  struct snd_soc_codec *codec)
+{
+        struct snd_ac97_gpio_priv *gpio_priv;
+        int ret;
+
+        gpio_priv = devm_kzalloc(codec->dev, sizeof(*gpio_priv), GFP_KERNEL);
+        if (!gpio_priv)
+                return -ENOMEM;
+        ac97->gpio_priv = gpio_priv;
+        gpio_priv->codec = codec;
+        gpio_priv->gpio_chip = snd_soc_ac97_gpio_chip;
+        gpio_priv->gpio_chip.ngpio = AC97_NUM_GPIOS;
+        gpio_priv->gpio_chip.dev = codec->dev;
+        gpio_priv->gpio_chip.base = -1;
+
+        ret = gpiochip_add(&gpio_priv->gpio_chip);
+        if (ret != 0)
+                dev_err(codec->dev, "Failed to add GPIOs: %d\n", ret);
+        return ret;
+}
+
+static void snd_soc_ac97_free_gpio(struct snd_ac97 *ac97)
+{
+        gpiochip_remove(&ac97->gpio_priv->gpio_chip);
+}
+#else
+static int snd_soc_ac97_init_gpio(struct snd_ac97 *ac97,
+                                  struct snd_soc_codec *codec)
+{
+        return 0;
+}
+
+static void snd_soc_ac97_free_gpio(struct snd_ac97 *ac97)
+{
+}
+#endif
+
 /**
  * snd_soc_alloc_ac97_codec() - Allocate new a AC'97 device
  * @codec: The CODEC for which to create the AC'97 device
@@ -119,6 +239,10 @@ struct snd_ac97 *snd_soc_new_ac97_codec(struct snd_soc_codec *codec,
         if (ret)
                 goto err_put_device;
 
+        ret = snd_soc_ac97_init_gpio(ac97, codec);
+        if (ret)
+                goto err_put_device;
+
         return ac97;
 
 err_put_device:
@@ -135,6 +259,7 @@ EXPORT_SYMBOL_GPL(snd_soc_new_ac97_codec);
  */
 void snd_soc_free_ac97_codec(struct snd_ac97 *ac97)
 {
+        snd_soc_ac97_free_gpio(ac97);
         device_del(&ac97->dev);
         ac97->bus = NULL;
         put_device(&ac97->dev);