[PATCH 1/1] pinctrl: sunxi: add GPIO get_direction callback

[James Hilliard]

Implement sunxi_pinctrl_gpio_get_direction() and wire it into
the sunxi gpio_chip setup.

The new callback reads the pin mux register and compares the mux
value against the pin descriptor gpio_in and gpio_out functions
to report GPIO_LINE_DIRECTION_IN or GPIO_LINE_DIRECTION_OUT.
If the pin is muxed to irq, report it as input.

Signed-off-by: James Hilliard <james.hilliard1 at gmail.com>
---
 drivers/pinctrl/sunxi/pinctrl-sunxi.c | 32 +++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/drivers/pinctrl/sunxi/pinctrl-sunxi.c b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
index 0fb057a07dcc..424f23be27b2 100644
--- a/drivers/pinctrl/sunxi/pinctrl-sunxi.c
+++ b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
@@ -995,6 +995,37 @@ static int sunxi_pinctrl_gpio_direction_output(struct gpio_chip *chip,
 					    chip->base + offset, false);
 }
 
+static int sunxi_pinctrl_gpio_get_direction(struct gpio_chip *chip,
+					    unsigned int offset)
+{
+	struct sunxi_pinctrl *pctl = gpiochip_get_data(chip);
+	struct sunxi_desc_function *in, *out, *irq;
+	u32 reg, shift, mask, val;
+	u16 pin = chip->base + offset;
+
+	in = sunxi_pinctrl_desc_find_function_by_pin(pctl, pin, "gpio_in");
+	out = sunxi_pinctrl_desc_find_function_by_pin(pctl, pin, "gpio_out");
+	if (!in || !out)
+		return -EINVAL;
+
+	irq = sunxi_pinctrl_desc_find_function_by_pin(pctl, pin, "irq");
+
+	sunxi_mux_reg(pctl, offset, &reg, &shift, &mask);
+	val = (readl(pctl->membase + reg) & mask) >> shift;
+
+	if (val == in->muxval)
+		return GPIO_LINE_DIRECTION_IN;
+
+	if (val == out->muxval)
+		return GPIO_LINE_DIRECTION_OUT;
+
+	/* IRQ function is effectively input. */
+	if (irq && val == irq->muxval)
+		return GPIO_LINE_DIRECTION_IN;
+
+	return -EINVAL;
+}
+
 static int sunxi_pinctrl_gpio_of_xlate(struct gpio_chip *gc,
 				const struct of_phandle_args *gpiospec,
 				u32 *flags)
@@ -1603,6 +1634,7 @@ int sunxi_pinctrl_init_with_flags(struct platform_device *pdev,
 	pctl->chip->set_config = gpiochip_generic_config;
 	pctl->chip->direction_input = sunxi_pinctrl_gpio_direction_input;
 	pctl->chip->direction_output = sunxi_pinctrl_gpio_direction_output;
+	pctl->chip->get_direction = sunxi_pinctrl_gpio_get_direction;
 	pctl->chip->get = sunxi_pinctrl_gpio_get;
 	pctl->chip->set = sunxi_pinctrl_gpio_set;
 	pctl->chip->of_xlate = sunxi_pinctrl_gpio_of_xlate;
-- 
2.43.0