mfd: Add WM831x revision B support

Revision B of the WM831x devices changes the sense of the tristate
bit for GPIO configuration, inverting it to become an enable instead.
Take account of this in the gpiolib driver.

A current sink regulation status bit has also been added in revision B,
add a flag indicating if it's present but don't use it yet.

This revision also adds an interrupt on key up for the ON pin event
which the existing code is able to take advantage of.

Signed-off-by: Mark Brown <[e-mail]>
Signed-off-by: Samuel Ortiz <[e-mail]>

drivers/gpio/wm831x-gpio.c

···
 {
 	struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
 	struct wm831x *wm831x = wm831x_gpio->wm831x;
+	int val = WM831X_GPN_DIR;
+
+	if (wm831x->has_gpio_ena)
+		val |= WM831X_GPN_TRI;
 
 	return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
-			       WM831X_GPN_DIR | WM831X_GPN_TRI,
-			       WM831X_GPN_DIR);
+			       WM831X_GPN_DIR | WM831X_GPN_TRI, val);
 }
 
 static int wm831x_gpio_get(struct gpio_chip *chip, unsigned offset)
···
 {
 	struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
 	struct wm831x *wm831x = wm831x_gpio->wm831x;
+	int val = 0;
 	int ret;
 
+	if (wm831x->has_gpio_ena)
+		val |= WM831X_GPN_TRI;
+
 	ret = wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
-			      WM831X_GPN_DIR | WM831X_GPN_TRI, 0);
+			      WM831X_GPN_DIR | WM831X_GPN_TRI, val);
 	if (ret < 0)
 		return ret;
 
···
 {
 	struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
 	struct wm831x *wm831x = wm831x_gpio->wm831x;
-	int i;
+	int i, tristated;
 
 	for (i = 0; i < chip->ngpio; i++) {
 		int gpio = i + chip->base;
···
 			break;
 		}
 
+		tristated = reg & WM831X_GPN_TRI;
+		if (wm831x->has_gpio_ena)
+			tristated = !tristated;
+
 		seq_printf(s, " %s %s %s %s%s\n"
 			   "                                  %s%s (0x%4x)\n",
 			   reg & WM831X_GPN_DIR ? "in" : "out",
···
 			   powerdomain,
 			   reg & WM831X_GPN_POL ? "" : " inverted",
 			   reg & WM831X_GPN_OD ? "open-drain" : "CMOS",
-			   reg & WM831X_GPN_TRI ? " tristated" : "",
+			   tristated ? " tristated" : "",
 			   reg);
 	}
 }

drivers/mfd/wm831x-core.c

···
 	case WM8310:
 		parent = WM8310;
 		wm831x->num_gpio = 16;
+		if (rev > 0) {
+			wm831x->has_gpio_ena = 1;
+			wm831x->has_cs_sts = 1;
+		}
+
 		dev_info(wm831x->dev, "WM8310 revision %c\n", 'A' + rev);
 		break;
 
 	case WM8311:
 		parent = WM8311;
 		wm831x->num_gpio = 16;
+		if (rev > 0) {
+			wm831x->has_gpio_ena = 1;
+			wm831x->has_cs_sts = 1;
+		}
+
 		dev_info(wm831x->dev, "WM8311 revision %c\n", 'A' + rev);
 		break;
 
 	case WM8312:
 		parent = WM8312;
 		wm831x->num_gpio = 16;
+		if (rev > 0) {
+			wm831x->has_gpio_ena = 1;
+			wm831x->has_cs_sts = 1;
+		}
+
 		dev_info(wm831x->dev, "WM8312 revision %c\n", 'A' + rev);
 		break;
 

include/linux/mfd/wm831x/core.h

···
 	int irq_masks_cur[WM831X_NUM_IRQ_REGS];   /* Currently active value */
 	int irq_masks_cache[WM831X_NUM_IRQ_REGS]; /* Cached hardware value */
 
+	/* Chip revision based flags */
+	unsigned has_gpio_ena:1;  /* Has GPIO enable bit */
+	unsigned has_cs_sts:1;    /* Has current sink status bit */
+
 	int num_gpio;
 
 	struct mutex auxadc_lock;

include/linux/mfd/wm831x/gpio.h

···
 #define WM831X_GPN_OD_MASK                      0x0200  /* GPN_OD */
 #define WM831X_GPN_OD_SHIFT                          9  /* GPN_OD */
 #define WM831X_GPN_OD_WIDTH                          1  /* GPN_OD */
+#define WM831X_GPN_ENA                          0x0080  /* GPN_ENA */
+#define WM831X_GPN_ENA_MASK                     0x0080  /* GPN_ENA */
+#define WM831X_GPN_ENA_SHIFT                         7  /* GPN_ENA */
+#define WM831X_GPN_ENA_WIDTH                         1  /* GPN_ENA */
 #define WM831X_GPN_TRI                          0x0080  /* GPN_TRI */
 #define WM831X_GPN_TRI_MASK                     0x0080  /* GPN_TRI */
 #define WM831X_GPN_TRI_SHIFT                         7  /* GPN_TRI */