Commit 00185165 authored by Andres Salomon's avatar Andres Salomon Committed by Linus Torvalds
Browse files

cs5535-gpio: don't apply errata #36 to edge detect GPIOs 



The edge detect status GPIOs function differently from the other atomic
model CS5536 GPIO registers; writing 1 to the high bits clears the GPIO,
but writing 1 to the lower bits also clears the bit.

This means that read-modify-write doesn't actually work for it, so don't
apply the errata here.  If a negative edge status gets lost after
resume..  well, we tried our best!

Tested-by: default avatarDaniel Drake <dsd@laptop.org>
Signed-off-by: default avatarAndres Salomon <dilinger@queued.net>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e819eb86

drivers/gpio/cs5535-gpio.c

+11 −4
Original line number Diff line number Diff line
@@ -56,14 +56,21 @@ static struct cs5535_gpio_chip { 
 * registers, see include/linux/cs5535.h.

 */



static void errata_outl(u32 val, unsigned long addr)

static void errata_outl(struct cs5535_gpio_chip *chip, u32 val,

		unsigned int reg)

{

	unsigned long addr = chip->base + 0x80 + reg;



	/*

	 * According to the CS5536 errata (#36), after suspend

	 * a write to the high bank GPIO register will clear all

	 * non-selected bits; the recommended workaround is a

	 * read-modify-write operation.

	 *

	 * Don't apply this errata to the edge status GPIOs, as writing

	 * to their lower bits will clear them.

	 */

	if (reg != GPIO_POSITIVE_EDGE_STS && reg != GPIO_NEGATIVE_EDGE_STS)

		val |= inl(addr);

	outl(val, addr);

}
@@ -76,7 +83,7 @@ static void __cs5535_gpio_set(struct cs5535_gpio_chip *chip, unsigned offset, 
		outl(1 << offset, chip->base + reg);

	else

		/* high bank register */

		errata_outl(1 << (offset - 16), chip->base + 0x80 + reg);

		errata_outl(chip, 1 << (offset - 16), reg);

}



void cs5535_gpio_set(unsigned offset, unsigned int reg)
@@ -98,7 +105,7 @@ static void __cs5535_gpio_clear(struct cs5535_gpio_chip *chip, unsigned offset, 
		outl(1 << (offset + 16), chip->base + reg);

	else

		/* high bank register */

		errata_outl(1 << offset, chip->base + 0x80 + reg);

		errata_outl(chip, 1 << offset, reg);

}



void cs5535_gpio_clear(unsigned offset, unsigned int reg)

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