--- /dev/null
+RT5677 audio CODEC
+
+This device supports I2C only.
+
+Required properties:
+
+- compatible : "realtek,rt5677".
+
+- reg : The I2C address of the device.
+
+- interrupts : The CODEC's interrupt output.
+
+Optional properties:
+
+- realtek,pow-ldo2-gpio : The GPIO that controls the CODEC's POW_LDO2 pin.
+
+Pins on the device (for linking into audio routes):
+
+  * IN1P
+  * IN1N
+  * IN2P
+  * IN2N
+  * MICBIAS1
+  * DMIC1
+  * DMIC2
+  * DMIC3
+  * DMIC4
+  * LOUT1
+  * LOUT2
+  * LOUT3
+
+Example:
+
+rt5677 {
+       compatible = "realtek,rt5677";
+       reg = <0x2c>;
+       interrupt-parent = <&gpio>;
+       interrupts = <TEGRA_GPIO(W, 3) GPIO_ACTIVE_HIGH>;
+       realtek,pow-ldo2-gpio =
+               <&gpio TEGRA_GPIO(V, 3) GPIO_ACTIVE_HIGH>;
+};
 
 #include <linux/init.h>
 #include <linux/delay.h>
 #include <linux/pm.h>
+#include <linux/of_gpio.h>
 #include <linux/regmap.h>
 #include <linux/i2c.h>
 #include <linux/platform_device.h>
        struct rt5677_priv *rt5677 = snd_soc_codec_get_drvdata(codec);
 
        regmap_write(rt5677->regmap, RT5677_RESET, 0x10ec);
+       if (gpio_is_valid(rt5677->pow_ldo2))
+               gpio_set_value_cansleep(rt5677->pow_ldo2, 0);
 
        return 0;
 }
 
        regcache_cache_only(rt5677->regmap, true);
        regcache_mark_dirty(rt5677->regmap);
+       if (gpio_is_valid(rt5677->pow_ldo2))
+               gpio_set_value_cansleep(rt5677->pow_ldo2, 0);
 
        return 0;
 }
 {
        struct rt5677_priv *rt5677 = snd_soc_codec_get_drvdata(codec);
 
+       if (gpio_is_valid(rt5677->pow_ldo2)) {
+               gpio_set_value_cansleep(rt5677->pow_ldo2, 1);
+               msleep(10);
+       }
        regcache_cache_only(rt5677->regmap, false);
        regcache_sync(rt5677->regmap);
 
 };
 MODULE_DEVICE_TABLE(i2c, rt5677_i2c_id);
 
+static int rt5677_parse_dt(struct rt5677_priv *rt5677, struct device_node *np)
+{
+       rt5677->pow_ldo2 = of_get_named_gpio(np,
+                                       "realtek,pow-ldo2-gpio", 0);
+
+       /*
+        * POW_LDO2 is optional (it may be statically tied on the board).
+        * -ENOENT means that the property doesn't exist, i.e. there is no
+        * GPIO, so is not an error. Any other error code means the property
+        * exists, but could not be parsed.
+        */
+       if (!gpio_is_valid(rt5677->pow_ldo2) &&
+                       (rt5677->pow_ldo2 != -ENOENT))
+               return rt5677->pow_ldo2;
+
+       return 0;
+}
+
 static int rt5677_i2c_probe(struct i2c_client *i2c,
                    const struct i2c_device_id *id)
 {
        if (pdata)
                rt5677->pdata = *pdata;
 
+       if (i2c->dev.of_node) {
+               ret = rt5677_parse_dt(rt5677, i2c->dev.of_node);
+               if (ret) {
+                       dev_err(&i2c->dev, "Failed to parse device tree: %d\n",
+                               ret);
+                       return ret;
+               }
+       } else {
+               rt5677->pow_ldo2 = -EINVAL;
+       }
+
+       if (gpio_is_valid(rt5677->pow_ldo2)) {
+               ret = devm_gpio_request_one(&i2c->dev, rt5677->pow_ldo2,
+                                           GPIOF_OUT_INIT_HIGH,
+                                           "RT5677 POW_LDO2");
+               if (ret < 0) {
+                       dev_err(&i2c->dev, "Failed to request POW_LDO2 %d: %d\n",
+                               rt5677->pow_ldo2, ret);
+                       return ret;
+               }
+               /* Wait a while until I2C bus becomes available. The datasheet
+                * does not specify the exact we should wait but startup
+                * sequence mentiones at least a few milliseconds.
+                */
+               msleep(10);
+       }
+
        rt5677->regmap = devm_regmap_init_i2c(i2c, &rt5677_regmap);
        if (IS_ERR(rt5677->regmap)) {
                ret = PTR_ERR(rt5677->regmap);