mfd: Mark WM1811 GPIO6 register volatile for later revisions

For later chip revisions the WM1811 GPIO6 register is always volatile so
store the device revision when initialising the driver and then check at
runtime if we're running on a newer device.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/mfd/wm8994-core.c

@@ -446,15 +446,16 @@ static int wm8994_device_init(struct wm8994 *wm8994, int irq)
 			ret);
 		goto err_enable;
 	}
+	wm8994->revision = ret;
 
 	switch (wm8994->type) {
 	case WM8994:
-		switch (ret) {
+		switch (wm8994->revision) {
 		case 0:
 		case 1:
 			dev_warn(wm8994->dev,
 				 "revision %c not fully supported\n",
-				 'A' + ret);
+				 'A' + wm8994->revision);
 			break;
 		default:
 			break;
@@ -462,14 +463,15 @@ static int wm8994_device_init(struct wm8994 *wm8994, int irq)
 		break;
 	case WM1811:
 		/* Revision C did not change the relevant layer */
-		if (ret > 1)
-			ret++;
+		if (wm8994->revision > 1)
+			wm8994->revision++;
 		break;
 	default:
 		break;
 	}
 
-	dev_info(wm8994->dev, "%s revision %c\n", devname, 'A' + ret);
+	dev_info(wm8994->dev, "%s revision %c\n", devname,
+		 'A' + wm8994->revision);
 
 	switch (wm8994->type) {
 	case WM1811:

drivers/mfd/wm8994-regmap.c

@@ -12,6 +12,7 @@
  *
  */
 
+#include <linux/mfd/wm8994/core.h>
 #include <linux/mfd/wm8994/registers.h>
 #include <linux/regmap.h>
 
@@ -210,7 +211,6 @@ static struct reg_default wm1811_defaults[] = {
 	{ 0x0702, 0xA101 },    /* R1794 - Pull Control (BCLK2) */
 	{ 0x0703, 0xA101 },    /* R1795 - Pull Control (DACLRCLK2) */
 	{ 0x0704, 0xA101 },    /* R1796 - Pull Control (DACDAT2) */
-	{ 0x0705, 0xA101 },    /* R1797 - GPIO 6 */
 	{ 0x0707, 0xA101 },    /* R1799 - GPIO 8 */
 	{ 0x0708, 0xA101 },    /* R1800 - GPIO 9 */
 	{ 0x0709, 0xA101 },    /* R1801 - GPIO 10 */
@@ -1145,6 +1145,21 @@ static bool wm8994_volatile_register(struct device *dev, unsigned int reg)
 	}
 }
 
+static bool wm1811_volatile_register(struct device *dev, unsigned int reg)
+{
+	struct wm8994 *wm8994 = dev_get_drvdata(dev);
+
+	switch (reg) {
+	case WM8994_GPIO_6:
+		if (wm8994->revision > 1)
+			return true;
+		else
+			return false;
+	default:
+		return wm8994_volatile_register(dev, reg);
+	}
+}
+
 static bool wm8958_volatile_register(struct device *dev, unsigned int reg)
 {
 	switch (reg) {
@@ -1185,7 +1200,7 @@ struct regmap_config wm1811_regmap_config = {
 	.num_reg_defaults = ARRAY_SIZE(wm1811_defaults),
 
 	.max_register = WM8994_MAX_REGISTER,
-	.volatile_reg = wm8994_volatile_register,
+	.volatile_reg = wm1811_volatile_register,
 	.readable_reg = wm1811_readable_register,
 };
 

include/linux/mfd/wm8994/core.h

@@ -56,6 +56,7 @@ struct wm8994 {
 	struct mutex irq_lock;
 
 	enum wm8994_type type;
+	int revision;
 
 	struct device *dev;
 	struct regmap *regmap;