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path: root/drivers/gpio/cs5535-gpio.c
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Diffstat (limited to 'drivers/gpio/cs5535-gpio.c')
-rw-r--r--drivers/gpio/cs5535-gpio.c27
1 files changed, 25 insertions, 2 deletions
diff --git a/drivers/gpio/cs5535-gpio.c b/drivers/gpio/cs5535-gpio.c
index e23c068..d3e55a0 100644
--- a/drivers/gpio/cs5535-gpio.c
+++ b/drivers/gpio/cs5535-gpio.c
@@ -56,6 +56,29 @@ static struct cs5535_gpio_chip {
* registers, see include/linux/cs5535.h.
*/
+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) {
+ if (val & 0xffff)
+ val |= (inl(addr) & 0xffff); /* ignore the high bits */
+ else
+ val |= (inl(addr) ^ (val >> 16));
+ }
+ outl(val, addr);
+}
+
static void __cs5535_gpio_set(struct cs5535_gpio_chip *chip, unsigned offset,
unsigned int reg)
{
@@ -64,7 +87,7 @@ static void __cs5535_gpio_set(struct cs5535_gpio_chip *chip, unsigned offset,
outl(1 << offset, chip->base + reg);
else
/* high bank register */
- outl(1 << (offset - 16), chip->base + 0x80 + reg);
+ errata_outl(chip, 1 << (offset - 16), reg);
}
void cs5535_gpio_set(unsigned offset, unsigned int reg)
@@ -86,7 +109,7 @@ static void __cs5535_gpio_clear(struct cs5535_gpio_chip *chip, unsigned offset,
outl(1 << (offset + 16), chip->base + reg);
else
/* high bank register */
- 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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