diff mbox

[2/2] gpio: htc-egpio: read output value from cache

Message ID 1480496968-5829-1-git-send-email-linus.walleij@linaro.org
State Accepted
Commit 24b35ed9a84ab1e7ad96c67434841120ca7fbf36
Headers show

Commit Message

Linus Walleij Nov. 30, 2016, 9:09 a.m. UTC 
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>

---
 drivers/gpio/gpio-htc-egpio.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

-- 
2.7.4

--
To unsubscribe from this list: send the line "unsubscribe linux-gpio" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

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)