2013-07-26 20:40:23

by Andrew Chew

Subject: [PATCH V2] gpio: palmas: Fix misreported GPIO out value

It seems that the value read back from the PALMAS_GPIO_DATA_IN register
isn't valid if the GPIO direction is out. When that's the case, we can
read back the PALMAS_GPIO_DATA_OUT register to get the proper output value.

Change-Id: Iaf877e538cfdb37a6759c45ec3c6e4ee31078709
Signed-off-by: Andrew Chew <[email protected]>
---
V2: Fixed a warning from using test_bit with an int instead of long. Keeping
the int and just masking that bit in the raw now.

drivers/gpio/gpio-palmas.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpio-palmas.c b/drivers/gpio/gpio-palmas.c
index e3a4e56..723825d 100644
--- a/drivers/gpio/gpio-palmas.c
+++ b/drivers/gpio/gpio-palmas.c
@@ -43,9 +43,22 @@ static int palmas_gpio_get(struct gpio_chip *gc, unsigned offset)
unsigned int val;
int ret;

- ret = palmas_read(palmas, PALMAS_GPIO_BASE, PALMAS_GPIO_DATA_IN, &val);
+ ret = palmas_read(palmas, PALMAS_GPIO_BASE, PALMAS_GPIO_DATA_DIR, &val);
if (ret < 0) {
- dev_err(gc->dev, "GPIO_DATA_IN read failed, err = %d\n", ret);
+ dev_err(gc->dev, "GPIO_DATA_DIR read failed, err = %d\n", ret);
+ return ret;
+ }
+
+ if (val & (1 << offset)) {
+ ret = palmas_read(palmas, PALMAS_GPIO_BASE,
+ PALMAS_GPIO_DATA_OUT, &val);
+ } else {
+ ret = palmas_read(palmas, PALMAS_GPIO_BASE,
+ PALMAS_GPIO_DATA_IN, &val);
+ }
+ if (ret < 0) {
+ dev_err(gc->dev, "GPIO_DATA_IN/OUT read failed, err = %d\n",
+ ret);
return ret;
}
return !!(val & BIT(offset));
--
1.8.1.5

2013-07-29 05:48:14

by Laxman Dewangan

Subject: Re: [PATCH V2] gpio: palmas: Fix misreported GPIO out value

On Saturday 27 July 2013 02:09 AM, Andrew Chew wrote:
> It seems that the value read back from the PALMAS_GPIO_DATA_IN register
> isn't valid if the GPIO direction is out. When that's the case, we can
> read back the PALMAS_GPIO_DATA_OUT register to get the proper output value.

Looks good to me.
Acked-by: Laxman Dewangan <[email protected]>

2013-08-16 13:06:16

by Linus Walleij

Subject: Re: [PATCH V2] gpio: palmas: Fix misreported GPIO out value

On Fri, Jul 26, 2013 at 10:39 PM, Andrew Chew <[email protected]> wrote:

> It seems that the value read back from the PALMAS_GPIO_DATA_IN register
> isn't valid if the GPIO direction is out. When that's the case, we can
> read back the PALMAS_GPIO_DATA_OUT register to get the proper output value.
>
> Change-Id: Iaf877e538cfdb37a6759c45ec3c6e4ee31078709

Very interesting that you use gerrit, but the kernel community does not
want this.

> Signed-off-by: Andrew Chew <[email protected]>
> ---
> V2: Fixed a warning from using test_bit with an int instead of long. Keeping
> the int and just masking that bit in the raw now.

Applied with change-id stripped and Laxman's ACK.

Yours,
Linus Walleij