1 files changed, 25 insertions, 2 deletions

diff --git a/drivers/gpio/cs5535-gpio.c b/drivers/gpio/cs5535-gpio.c
index e23c06893d19..d3e55a0ae92b 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)