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authorLinus Walleij <linus.walleij@linaro.org>2016-11-13 11:50:22 +0100
committerLinus Walleij <linus.walleij@linaro.org>2016-11-13 11:50:22 +0100
commit24b35ed9a84ab1e7ad96c67434841120ca7fbf36 (patch)
tree54ce2241c790ed49839ff41f4cfa71bfd0d81a2e /drivers/gpio
parentgpio: htc-egpio: add .get_direction() support (diff)
downloadlinux-dev-24b35ed9a84ab1e7ad96c67434841120ca7fbf36.tar.xz
linux-dev-24b35ed9a84ab1e7ad96c67434841120ca7fbf36.zip
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>
Diffstat (limited to 'drivers/gpio')
-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)