pinctrl: axp209: Add support for GPIO3 on the AXP209

The AXP209 device has a 4th GPIO which has a slightly different register
setup, where the control + status bits are held in a single register
rather than sharing AXP20X_GPIO20_SS with GPIOs 0-2.
Signed-off-by: Jonathan McDowell <noodles@earth.li>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/dde40307f0ebc23b9841c32e702b481ab5193dc4.1684258957.git.noodles@earth.liSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-axp209.c

@@ -30,6 +30,11 @@
 #define AXP20X_GPIO_FUNCTION_OUT_HIGH	1
 #define AXP20X_GPIO_FUNCTION_INPUT	2
 
+#define AXP20X_GPIO3_FUNCTIONS		GENMASK(2, 1)
+#define AXP20X_GPIO3_FUNCTION_OUT_LOW	0
+#define AXP20X_GPIO3_FUNCTION_OUT_HIGH	2
+#define AXP20X_GPIO3_FUNCTION_INPUT	4
+
 #define AXP20X_FUNC_GPIO_OUT		0
 #define AXP20X_FUNC_GPIO_IN		1
 #define AXP20X_FUNC_LDO			2
@@ -73,6 +78,7 @@ static const struct pinctrl_pin_desc axp209_pins[] = {
 	PINCTRL_PIN(0, "GPIO0"),
 	PINCTRL_PIN(1, "GPIO1"),
 	PINCTRL_PIN(2, "GPIO2"),
+	PINCTRL_PIN(3, "GPIO3"),
 };
 
 static const struct pinctrl_pin_desc axp22x_pins[] = {
@@ -130,6 +136,14 @@ static int axp20x_gpio_get(struct gpio_chip *chip, unsigned int offset)
 	unsigned int val;
 	int ret;
 
+	/* AXP209 has GPIO3 status sharing the settings register */
+	if (offset == 3) {
+		ret = regmap_read(pctl->regmap, AXP20X_GPIO3_CTRL, &val);
+		if (ret)
+			return ret;
+		return !!(val & BIT(0));
+	}
+
 	ret = regmap_read(pctl->regmap, AXP20X_GPIO20_SS, &val);
 	if (ret)
 		return ret;
@@ -144,6 +158,17 @@ static int axp20x_gpio_get_direction(struct gpio_chip *chip,
 	unsigned int val;
 	int reg, ret;
 
+	/* AXP209 GPIO3 settings have a different layout */
+	if (offset == 3) {
+		ret = regmap_read(pctl->regmap, AXP20X_GPIO3_CTRL, &val);
+		if (ret)
+			return ret;
+		if (val & AXP20X_GPIO3_FUNCTION_INPUT)
+			return GPIO_LINE_DIRECTION_IN;
+
+		return GPIO_LINE_DIRECTION_OUT;
+	}
+
 	reg = axp20x_gpio_get_reg(offset);
 	if (reg < 0)
 		return reg;
@@ -184,6 +209,15 @@ static void axp20x_gpio_set(struct gpio_chip *chip, unsigned int offset,
 	struct axp20x_pctl *pctl = gpiochip_get_data(chip);
 	int reg;
 
+	/* AXP209 has GPIO3 status sharing the settings register */
+	if (offset == 3) {
+		regmap_update_bits(pctl->regmap, AXP20X_GPIO3_CTRL,
+				   AXP20X_GPIO3_FUNCTIONS,
+				   value ? AXP20X_GPIO3_FUNCTION_OUT_HIGH :
+				   AXP20X_GPIO3_FUNCTION_OUT_LOW);
+		return;
+	}
+
 	reg = axp20x_gpio_get_reg(offset);
 	if (reg < 0)
 		return;
@@ -200,6 +234,14 @@ static int axp20x_pmx_set(struct pinctrl_dev *pctldev, unsigned int offset,
 	struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);
 	int reg;
 
+	/* AXP209 GPIO3 settings have a different layout */
+	if (offset == 3) {
+		return regmap_update_bits(pctl->regmap, AXP20X_GPIO3_CTRL,
+				   AXP20X_GPIO3_FUNCTIONS,
+				   config == AXP20X_MUX_GPIO_OUT ? AXP20X_GPIO3_FUNCTION_OUT_LOW :
+				   AXP20X_GPIO3_FUNCTION_INPUT);
+	}
+
 	reg = axp20x_gpio_get_reg(offset);
 	if (reg < 0)
 		return reg;