Commit 01e10d02 authored by Chen-Yu Tsai's avatar Chen-Yu Tsai Committed by Linus Walleij
Browse files

pinctrl: sunxi: Implement gpiochip::get_direction() 



After commit 471e998c ("gpiolib: remove redundant callback check"),
a warning will be printed if the gpio driver does not implement this
callback. The warning was added in commit e623c430 ("gpiolib:
sanitize the return value of gpio_chip::get_direction()"), but was
masked by the "redundant" check.

The warning can be triggered by any action that calls the callback,
such as dumping the GPIO state from /sys/kernel/debug/gpio.

Implement it for the sunxi driver. This is simply a matter of reading
out the mux value from the registers, then checking if it is one of
the GPIO functions and which direction it is.

Signed-off-by: default avatarChen-Yu Tsai <wens@kernel.org>
Reviewed-by: default avatarJernej Skrabec <jernej.skrabec@gmail.com>
Reviewed-by: default avatarBartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Reviewed-by: default avatarAndre Przywara <andre.przywara@arm.com>
Signed-off-by: default avatarLinus Walleij <linusw@kernel.org>
parent 45fe4592

drivers/pinctrl/sunxi/pinctrl-sunxi.c

+51 −0
Original line number Diff line number Diff line
@@ -204,6 +204,32 @@ sunxi_pinctrl_desc_find_function_by_pin(struct sunxi_pinctrl *pctl, 
	return NULL;

}



static struct sunxi_desc_function *

sunxi_pinctrl_desc_find_function_by_pin_and_mux(struct sunxi_pinctrl *pctl,

						const u16 pin_num,

						const u8 muxval)

{

	for (unsigned int i = 0; i < pctl->desc->npins; i++) {

		const struct sunxi_desc_pin *pin = pctl->desc->pins + i;

		struct sunxi_desc_function *func = pin->functions;



		if (pin->pin.number != pin_num)

			continue;



		if (pin->variant && !(pctl->variant & pin->variant))

			continue;



		while (func->name) {

			if (func->muxval == muxval)

				return func;



			func++;

		}

	}



	return NULL;

}



static int sunxi_pctrl_get_groups_count(struct pinctrl_dev *pctldev)

{

	struct sunxi_pinctrl *pctl = pinctrl_dev_get_drvdata(pctldev);
@@ -930,6 +956,30 @@ static const struct pinmux_ops sunxi_pmx_ops = { 
	.strict			= true,

};



static int sunxi_pinctrl_gpio_get_direction(struct gpio_chip *chip,

					    unsigned int offset)

{

	struct sunxi_pinctrl *pctl = gpiochip_get_data(chip);

	const struct sunxi_desc_function *func;

	u32 pin = offset + chip->base;

	u32 reg, shift, mask;

	u8 muxval;



	sunxi_mux_reg(pctl, offset, &reg, &shift, &mask);



	muxval = (readl(pctl->membase + reg) & mask) >> shift;



	func = sunxi_pinctrl_desc_find_function_by_pin_and_mux(pctl, pin, muxval);

	if (!func)

		return -ENODEV;



	if (!strcmp(func->name, "gpio_out"))

		return GPIO_LINE_DIRECTION_OUT;

	if (!strcmp(func->name, "gpio_in") || !strcmp(func->name, "irq"))

		return GPIO_LINE_DIRECTION_IN;

	return -EINVAL;

}



static int sunxi_pinctrl_gpio_direction_input(struct gpio_chip *chip,

					unsigned offset)

{
@@ -1599,6 +1649,7 @@ int sunxi_pinctrl_init_with_flags(struct platform_device *pdev, 
	pctl->chip->request = gpiochip_generic_request;

	pctl->chip->free = gpiochip_generic_free;

	pctl->chip->set_config = gpiochip_generic_config;

	pctl->chip->get_direction = sunxi_pinctrl_gpio_get_direction;

	pctl->chip->direction_input = sunxi_pinctrl_gpio_direction_input;

	pctl->chip->direction_output = sunxi_pinctrl_gpio_direction_output;

	pctl->chip->get = sunxi_pinctrl_gpio_get;