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Commit 91492a44 authored by Rabin Vincent's avatar Rabin Vincent Committed by Linus Walleij
Browse files

gpio: generic: support input-only chips 



Allow chips to indicates that they are input-only and thus cannot set
the output value.  This will be used by the gpio-etraxfs driver.

Signed-off-by: default avatarRabin Vincent <rabin@rab.in>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 1296fba1

drivers/gpio/gpio-generic.c

+20 −3
Original line number Diff line number Diff line
@@ -153,6 +153,10 @@ static int bgpio_get(struct gpio_chip *gc, unsigned int gpio) 
	return !!(bgc->read_reg(bgc->reg_dat) & bgc->pin2mask(bgc, gpio));

}



static void bgpio_set_none(struct gpio_chip *gc, unsigned int gpio, int val)

{

}



static void bgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)

{

	struct bgpio_chip *bgc = to_bgpio_chip(gc);
@@ -279,6 +283,12 @@ static int bgpio_simple_dir_in(struct gpio_chip *gc, unsigned int gpio) 
	return 0;

}



static int bgpio_dir_out_err(struct gpio_chip *gc, unsigned int gpio,

				int val)

{

	return -EINVAL;

}



static int bgpio_simple_dir_out(struct gpio_chip *gc, unsigned int gpio,

				int val)

{
@@ -460,6 +470,9 @@ static int bgpio_setup_io(struct bgpio_chip *bgc, 
		bgc->reg_set = set;

		bgc->gc.set = bgpio_set_set;

		bgc->gc.set_multiple = bgpio_set_multiple_set;

	} else if (flags & BGPIOF_NO_OUTPUT) {

		bgc->gc.set = bgpio_set_none;

		bgc->gc.set_multiple = NULL;

	} else {

		bgc->gc.set = bgpio_set;

		bgc->gc.set_multiple = bgpio_set_multiple;
@@ -476,7 +489,8 @@ static int bgpio_setup_io(struct bgpio_chip *bgc, 


static int bgpio_setup_direction(struct bgpio_chip *bgc,

				 void __iomem *dirout,

				 void __iomem *dirin)

				 void __iomem *dirin,

				 unsigned long flags)

{

	if (dirout && dirin) {

		return -EINVAL;
@@ -491,6 +505,9 @@ static int bgpio_setup_direction(struct bgpio_chip *bgc, 
		bgc->gc.direction_input = bgpio_dir_in_inv;

		bgc->gc.get_direction = bgpio_get_dir_inv;

	} else {

		if (flags & BGPIOF_NO_OUTPUT)

			bgc->gc.direction_output = bgpio_dir_out_err;

		else

			bgc->gc.direction_output = bgpio_simple_dir_out;

		bgc->gc.direction_input = bgpio_simple_dir_in;

	}
@@ -543,7 +560,7 @@ int bgpio_init(struct bgpio_chip *bgc, struct device *dev, 
	if (ret)

		return ret;



	ret = bgpio_setup_direction(bgc, dirout, dirin);

	ret = bgpio_setup_direction(bgc, dirout, dirin, flags);

	if (ret)

		return ret;

include/linux/basic_mmio_gpio.h

+1 −0
Original line number Diff line number Diff line
@@ -75,5 +75,6 @@ int bgpio_init(struct bgpio_chip *bgc, struct device *dev, 
#define BGPIOF_UNREADABLE_REG_DIR	BIT(2) /* reg_dir is unreadable */

#define BGPIOF_BIG_ENDIAN_BYTE_ORDER	BIT(3)

#define BGPIOF_READ_OUTPUT_REG_SET     BIT(4) /* reg_set stores output value */

#define BGPIOF_NO_OUTPUT		BIT(5) /* only input */



#endif /* __BASIC_MMIO_GPIO_H */