ASoC: pxa: add devicetree support

Add the devicetree support, so that the driver can be used in a
devictree platform.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/arm/pxa2xx-ac97-lib.c

@@ -19,6 +19,7 @@
 #include <linux/module.h>
 #include <linux/io.h>
 #include <linux/gpio.h>
+#include <linux/of_gpio.h>
 
 #include <sound/pxa2xx-lib.h>
 
@@ -337,6 +338,17 @@ int pxa2xx_ac97_hw_probe(struct platform_device *dev)
 			dev_err(&dev->dev, "Invalid reset GPIO %d\n",
 				pdata->reset_gpio);
 		}
+	} else if (!pdata && dev->dev.of_node) {
+		pdata = devm_kzalloc(&dev->dev, sizeof(*pdata), GFP_KERNEL);
+		if (!pdata)
+			return -ENOMEM;
+		pdata->reset_gpio = of_get_named_gpio(dev->dev.of_node,
+						      "reset-gpios", 0);
+		if (pdata->reset_gpio == -ENOENT)
+			pdata->reset_gpio = -1;
+		else if (pdata->reset_gpio < 0)
+			return pdata->reset_gpio;
+		reset_gpio = pdata->reset_gpio;
 	} else {
 		if (cpu_is_pxa27x())
 			reset_gpio = 113;