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Commit 02308031 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'gpio-v4.15-5' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio 

Pull GPIO fix from Linus Walleij:
 "This is the (hopefully) last GPIO fix for v4.15, fixing the bit
  fiddling in the MMIO GPIO driver.

  Again the especially endowed screwer-upper who has been open coding
  bit fiddling is yours truly"

* tag 'gpio-v4.15-5' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: mmio: Also read bits that are zero
parents 1d966eb4 07c7b6a5

drivers/gpio/gpio-mmio.c

+16 −14
Original line number Original line Diff line number Diff line
@@ -152,14 +152,13 @@ static int bgpio_get_set_multiple(struct gpio_chip *gc, unsigned long *mask, 
{

{

	unsigned long get_mask = 0;

	unsigned long get_mask = 0;

	unsigned long set_mask = 0;

	unsigned long set_mask = 0;

	int bit = 0;





	while ((bit = find_next_bit(mask, gc->ngpio, bit)) != gc->ngpio) {

	/* Make sure we first clear any bits that are zero when we read the register */

		if (gc->bgpio_dir & BIT(bit))

	*bits &= ~*mask;

			set_mask |= BIT(bit);



		else

	/* Exploit the fact that we know which directions are set */

			get_mask |= BIT(bit);

	set_mask = *mask & gc->bgpio_dir;

	}

	get_mask = *mask & ~gc->bgpio_dir;





	if (set_mask)

	if (set_mask)

		*bits |= gc->read_reg(gc->reg_set) & set_mask;

		*bits |= gc->read_reg(gc->reg_set) & set_mask;
@@ -176,13 +175,13 @@ static int bgpio_get(struct gpio_chip *gc, unsigned int gpio) 




/*

/*

 * This only works if the bits in the GPIO register are in native endianness.

 * This only works if the bits in the GPIO register are in native endianness.

 * It is dirt simple and fast in this case. (Also the most common case.)

 */

 */

static int bgpio_get_multiple(struct gpio_chip *gc, unsigned long *mask,

static int bgpio_get_multiple(struct gpio_chip *gc, unsigned long *mask,

			      unsigned long *bits)

			      unsigned long *bits)

{

{



	/* Make sure we first clear any bits that are zero when we read the register */

	*bits = gc->read_reg(gc->reg_dat) & *mask;

	*bits &= ~*mask;

	*bits |= gc->read_reg(gc->reg_dat) & *mask;

	return 0;

	return 0;

}

}
@@ -196,9 +195,12 @@ static int bgpio_get_multiple_be(struct gpio_chip *gc, unsigned long *mask, 
	unsigned long val;

	unsigned long val;

	int bit;

	int bit;





	/* Make sure we first clear any bits that are zero when we read the register */

	*bits &= ~*mask;



	/* Create a mirrored mask */

	/* Create a mirrored mask */

	bit = 0;

	bit = -1;

	while ((bit = find_next_bit(mask, gc->ngpio, bit)) != gc->ngpio)

	while ((bit = find_next_bit(mask, gc->ngpio, bit + 1)) < gc->ngpio)

		readmask |= bgpio_line2mask(gc, bit);

		readmask |= bgpio_line2mask(gc, bit);





	/* Read the register */

	/* Read the register */
@@ -208,8 +210,8 @@ static int bgpio_get_multiple_be(struct gpio_chip *gc, unsigned long *mask, 
	 * Mirror the result into the "bits" result, this will give line 0

	 * Mirror the result into the "bits" result, this will give line 0

	 * in bit 0 ... line 31 in bit 31 for a 32bit register.

	 * in bit 0 ... line 31 in bit 31 for a 32bit register.

	 */

	 */

	bit = 0;

	bit = -1;

	while ((bit = find_next_bit(&val, gc->ngpio, bit)) != gc->ngpio)

	while ((bit = find_next_bit(&val, gc->ngpio, bit + 1)) < gc->ngpio)

		*bits |= bgpio_line2mask(gc, bit);

		*bits |= bgpio_line2mask(gc, bit);





	return 0;

	return 0;