[PATCH v4 13/39] pinctrl: qcom: stub support for special GPIOs

[Caleb Connolly]

Most platforms have a handful of "special" GPIOs, like the MMC
clock/data lanes, UFS reset, etc. These don't follow the usually naming
scheme of "gpioX" and also have unique capabilities and registers. We
can get away without supporting them all for now, but DT compatibility
is still an issue.

Add support for allowing these to be specified after the other pins, and
make all pinmux/pinconf calls for them nop.

Signed-off-by: Caleb Connolly <caleb.connolly at linaro.org>
---
 arch/arm/mach-snapdragon/include/mach/gpio.h |  2 ++
 drivers/gpio/msm_gpio.c                      | 20 ++++++++++++++++++++
 drivers/pinctrl/qcom/pinctrl-qcom.c          | 12 ++++++++++++
 3 files changed, 34 insertions(+)

diff --git a/arch/arm/mach-snapdragon/include/mach/gpio.h b/arch/arm/mach-snapdragon/include/mach/gpio.h
index 8dac62f870b9..c373f5a4cf3d 100644
--- a/arch/arm/mach-snapdragon/include/mach/gpio.h
+++ b/arch/arm/mach-snapdragon/include/mach/gpio.h
@@ -13,6 +13,8 @@
 struct msm_pin_data {
 	int pin_count;
 	const unsigned int *pin_offsets;
+	/* Index of first special pin, these are ignored for now */
+	unsigned int special_pins_start;
 };
 
 static inline u32 qcom_pin_offset(const unsigned int *offs, unsigned int selector)
diff --git a/drivers/gpio/msm_gpio.c b/drivers/gpio/msm_gpio.c
index 80cd28bb231f..8a5e8730e911 100644
--- a/drivers/gpio/msm_gpio.c
+++ b/drivers/gpio/msm_gpio.c
@@ -39,6 +39,10 @@ static int msm_gpio_direction_input(struct udevice *dev, unsigned int gpio)
 {
 	struct msm_gpio_bank *priv = dev_get_priv(dev);
 
+	/* Always NOP for special pins, assume they're in the correct state */
+	if (gpio >= priv->pin_data->special_pins_start)
+		return 0;
+
 	/* Disable OE bit */
 	clrsetbits_le32(priv->base + GPIO_CONFIG_REG(dev, gpio),
 			GPIO_OE_MASK, GPIO_OE_DISABLE);
@@ -50,6 +54,10 @@ static int msm_gpio_set_value(struct udevice *dev, unsigned int gpio, int value)
 {
 	struct msm_gpio_bank *priv = dev_get_priv(dev);
 
+	/* Always NOP for special pins, assume they're in the correct state */
+	if (gpio >= priv->pin_data->special_pins_start)
+		return 0;
+
 	value = !!value;
 	/* set value */
 	writel(value << GPIO_OUT, priv->base + GPIO_IN_OUT_REG(dev, gpio));
@@ -62,6 +70,10 @@ static int msm_gpio_direction_output(struct udevice *dev, unsigned int gpio,
 {
 	struct msm_gpio_bank *priv = dev_get_priv(dev);
 
+	/* Always NOP for special pins, assume they're in the correct state */
+	if (gpio >= priv->pin_data->special_pins_start)
+		return 0;
+
 	value = !!value;
 	/* set value */
 	writel(value << GPIO_OUT, priv->base + GPIO_IN_OUT_REG(dev, gpio));
@@ -76,6 +88,10 @@ static int msm_gpio_get_value(struct udevice *dev, unsigned int gpio)
 {
 	struct msm_gpio_bank *priv = dev_get_priv(dev);
 
+	/* Always NOP for special pins, assume they're in the correct state */
+	if (gpio >= priv->pin_data->special_pins_start)
+		return 0;
+
 	return !!(readl(priv->base + GPIO_IN_OUT_REG(dev, gpio)) >> GPIO_IN);
 }
 
@@ -83,6 +99,10 @@ static int msm_gpio_get_function(struct udevice *dev, unsigned int gpio)
 {
 	struct msm_gpio_bank *priv = dev_get_priv(dev);
 
+	/* Always NOP for special pins, assume they're in the correct state */
+	if (gpio >= priv->pin_data->special_pins_start)
+		return 0;
+
 	if (readl(priv->base + GPIO_CONFIG_REG(dev, gpio)) & GPIO_OE_ENABLE)
 		return GPIOF_OUTPUT;
 
diff --git a/drivers/pinctrl/qcom/pinctrl-qcom.c b/drivers/pinctrl/qcom/pinctrl-qcom.c
index dc3d8c4d9034..1ea4d21c41fc 100644
--- a/drivers/pinctrl/qcom/pinctrl-qcom.c
+++ b/drivers/pinctrl/qcom/pinctrl-qcom.c
@@ -83,6 +83,10 @@ static int msm_pinmux_set(struct udevice *dev, unsigned int pin_selector,
 {
 	struct msm_pinctrl_priv *priv = dev_get_priv(dev);
 
+	/* Always NOP for special pins, assume they're in the correct state */
+	if (pin_selector >= priv->data->pin_data.special_pins_start)
+		return 0;
+
 	clrsetbits_le32(priv->base + GPIO_CONFIG_REG(priv, pin_selector),
 			TLMM_FUNC_SEL_MASK | TLMM_GPIO_DISABLE,
 			priv->data->get_function_mux(func_selector) << 2);
@@ -94,6 +98,10 @@ static int msm_pinconf_set(struct udevice *dev, unsigned int pin_selector,
 {
 	struct msm_pinctrl_priv *priv = dev_get_priv(dev);
 
+	/* Always NOP for special pins */
+	if (pin_selector >= priv->data->pin_data.special_pins_start)
+		return 0;
+
 	switch (param) {
 	case PIN_CONFIG_DRIVE_STRENGTH:
 		argument = (argument / 2) - 1;
@@ -136,6 +144,10 @@ int msm_pinctrl_bind(struct udevice *dev)
 	const char *name;
 	int ret;
 
+	/* Make sure we don't indadvertently treat all pins as special pins. */
+	if (!data->pin_data.special_pins_start)
+		data->pin_data.special_pins_start = data->pin_data.pin_count;
+
 	drv = lists_driver_lookup_name("pinctrl_qcom");
 	if (!drv)
 		return -ENOENT;

-- 
2.43.1