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authorLinus Walleij2016-11-13 11:50:22 +0100
committerLinus Walleij2016-11-13 11:50:22 +0100
commit24b35ed9a84ab1e7ad96c67434841120ca7fbf36 (patch)
tree54ce2241c790ed49839ff41f4cfa71bfd0d81a2e
parent9298539c0472c1bd7516c62d444e561493e3f26c (diff)
gpio: htc-egpio: read output value from cache
When the hardware is in output mode, reading the value from the hardware is not giving the correct value back. Instead read the value from the cache so we get the right value. Suggested-by: Russell King <linux@arm.linux.org.uk> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
-rw-r--r--drivers/gpio/gpio-htc-egpio.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/drivers/gpio/gpio-htc-egpio.c b/drivers/gpio/gpio-htc-egpio.c
index 27af52850927..271356effb2e 100644
--- a/drivers/gpio/gpio-htc-egpio.c
+++ b/drivers/gpio/gpio-htc-egpio.c
@@ -160,10 +160,14 @@ static int egpio_get(struct gpio_chip *chip, unsigned offset)
bit = egpio_bit(ei, offset);
reg = egpio->reg_start + egpio_pos(ei, offset);
- value = egpio_readw(ei, reg);
- pr_debug("readw(%p + %x) = %x\n",
- ei->base_addr, reg << ei->bus_shift, value);
- return !!(value & bit);
+ if (test_bit(offset, &egpio->is_out)) {
+ return !!(egpio->cached_values & (1 << offset));
+ } else {
+ value = egpio_readw(ei, reg);
+ pr_debug("readw(%p + %x) = %x\n",
+ ei->base_addr, reg << ei->bus_shift, value);
+ return !!(value & bit);
+ }
}
static int egpio_direction_input(struct gpio_chip *chip, unsigned offset)