[1/2] gpio: mvebu: implement get_direction

Commit Message

Baruch Siach Jan. 10, 2019, 12:26 p.m. UTC

struct gpio_chip documentation recommends to always implement this
callback function.

A more concrete motivation is to be able (in combination with
GPIOD_ASIS) to detect whether the bootloader has changed the state of a
GPIO signal.

Signed-off-by: Baruch Siach <[e-mail]>
---
 drivers/gpio/gpio-mvebu.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

Comments

Linus Walleij Jan. 10, 2019, 3:20 p.m. UTC | #1

On Thu, Jan 10, 2019 at 1:27 PM Baruch Siach <[e-mail]> wrote:

> struct gpio_chip documentation recommends to always implement this
> callback function.
>
> A more concrete motivation is to be able (in combination with
> GPIOD_ASIS) to detect whether the bootloader has changed the state of a
> GPIO signal.
>
> Signed-off-by: Baruch Siach <[e-mail]>

This is strongly recommended for all drivers to implment so patch
applied.

Yours,
Linus Walleij

Patch

diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c
index 7d5c55494ccd..f97ed32b8beb 100644
--- a/drivers/gpio/gpio-mvebu.c
+++ b/drivers/gpio/gpio-mvebu.c
@@ -376,6 +376,16 @@  static int mvebu_gpio_direction_output(struct gpio_chip *chip, unsigned int pin,
 	return 0;
 }
 
+static int mvebu_gpio_get_direction(struct gpio_chip *chip, unsigned int pin)
+{
+	struct mvebu_gpio_chip *mvchip = gpiochip_get_data(chip);
+	u32 u;
+
+	regmap_read(mvchip->regs, GPIO_IO_CONF_OFF + mvchip->offset, &u);
+
+	return !!(u & BIT(pin));
+}
+
 static int mvebu_gpio_to_irq(struct gpio_chip *chip, unsigned int pin)
 {
 	struct mvebu_gpio_chip *mvchip = gpiochip_get_data(chip);
@@ -1130,6 +1140,7 @@  static int mvebu_gpio_probe(struct platform_device *pdev)
 	mvchip->chip.parent = &pdev->dev;
 	mvchip->chip.request = gpiochip_generic_request;
 	mvchip->chip.free = gpiochip_generic_free;
+	mvchip->chip.get_direction = mvebu_gpio_get_direction;
 	mvchip->chip.direction_input = mvebu_gpio_direction_input;
 	mvchip->chip.get = mvebu_gpio_get;
 	mvchip->chip.direction_output = mvebu_gpio_direction_output;