[PATCH 3.14 56/83] pinctrl: as3722: fix handling of GPIO invert bit

Greg Kroah-Hartman
2014-05-11T19:25:05Z

From: Andrew Bresticker <abrestic@chromium.org>

commit a73d2e30b46787d478275db36c19222020e29dc5 upstream.

The AS3722_GPIO_INV bit will always be blindly overwritten by
as3722_pinctrl_gpio_set_direction() and will be ignored when
setting the value of the GPIO in as3722_gpio_set() since the
enable_gpio_invert flag is never set. This will cause an
initially inverted GPIO to toggle when requested as an output,
which could be problematic if, for example, the GPIO controls
a critical regulator.

Instead of setting up the enable_gpio_invert flag, just leave
the invert bit alone and check it before setting the GPIO value.

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/pinctrl/pinctrl-as3722.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)

--- a/drivers/pinctrl/pinctrl-as3722.c
+++ b/drivers/pinctrl/pinctrl-as3722.c
@@ -64,7 +64,6 @@ struct as3722_pin_function {
};

struct as3722_gpio_pin_control {
- bool enable_gpio_invert;
unsigned mode_prop;
int io_function;
};
@@ -320,10 +319,8 @@ static int as3722_pinctrl_gpio_set_direc
return mode;
}

- if (as_pci->gpio_control[offset].enable_gpio_invert)
- mode |= AS3722_GPIO_INV;
-
- return as3722_write(as3722, AS3722_GPIOn_CONTROL_REG(offset), mode);
+ return as3722_update_bits(as3722, AS3722_GPIOn_CONTROL_REG(offset),
+ AS3722_GPIO_MODE_MASK, mode);
}

static const struct pinmux_ops as3722_pinmux_ops = {
@@ -496,10 +493,18 @@ static void as3722_gpio_set(struct gpio_
{
struct as3722_pctrl_info *as_pci = to_as_pci(chip);
struct as3722 *as3722 = as_pci->as3722;
- int en_invert = as_pci->gpio_control[offset].enable_gpio_invert;
+ int en_invert;
u32 val;
int ret;

+ ret = as3722_read(as3722, AS3722_GPIOn_CONTROL_REG(offset), &val);
+ if (ret < 0) {
+ dev_err(as_pci->dev,
+ "GPIO_CONTROL%d_REG read failed: %d\n", offset, ret);
+ return;
+ }
+ en_invert = !!(val & AS3722_GPIO_INV);
+
if (value)
val = (en_invert) ? 0 : AS3722_GPIOn_SIGNAL(offset);
else