In the generic pin config library, readback of some options are handled
differently compared to the setting of those options: the argument value
is used to convey enable/disable of an option in the set path, but
success or -EINVAL is used to convey if an option is enabled or disabled
in the debugfs readback path.

PIN_CONFIG_INPUT_SCHMITT_ENABLE is one such option. Fix the readback of
the option in the mediatek-paris library, so that the debugfs dump is
not showing "input schmitt enabled" for pins that don't have it enabled.

Fixes: 1bea6afbc842 ("pinctrl: mediatek: Refine mtk_pinconf_get()")
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
---
 drivers/pinctrl/mediatek/pinctrl-paris.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/pinctrl/mediatek/pinctrl-paris.c b/drivers/pinctrl/mediatek/pinctrl-paris.c
index b6bc31abd2b0..9353f78a52f0 100644
--- a/drivers/pinctrl/mediatek/pinctrl-paris.c
+++ b/drivers/pinctrl/mediatek/pinctrl-paris.c
@@ -193,6 +193,8 @@ static int mtk_pinconf_get(struct pinctrl_dev *pctldev,
 		}
 
 		err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_SMT, &ret);
+		if (!ret)
+			err = -EINVAL;
 		break;
 	case PIN_CONFIG_DRIVE_STRENGTH:
 		if (!hw->soc->drive_get)
-- 
2.44.0.396.g6e790dbe36-goog

On Wed, Mar 27, 2024 at 05:13:33PM +0800, Chen-Yu Tsai wrote:
> In the generic pin config library, readback of some options are handled
> differently compared to the setting of those options: the argument value
> is used to convey enable/disable of an option in the set path, but
> success or -EINVAL is used to convey if an option is enabled or disabled
> in the debugfs readback path.
> 
> PIN_CONFIG_INPUT_SCHMITT_ENABLE is one such option. Fix the readback of
> the option in the mediatek-paris library, so that the debugfs dump is
> not showing "input schmitt enabled" for pins that don't have it enabled.
> 
> Fixes: 1bea6afbc842 ("pinctrl: mediatek: Refine mtk_pinconf_get()")
> Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
> ---
>  drivers/pinctrl/mediatek/pinctrl-paris.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/pinctrl/mediatek/pinctrl-paris.c b/drivers/pinctrl/mediatek/pinctrl-paris.c
> index b6bc31abd2b0..9353f78a52f0 100644
> --- a/drivers/pinctrl/mediatek/pinctrl-paris.c
> +++ b/drivers/pinctrl/mediatek/pinctrl-paris.c
> @@ -193,6 +193,8 @@ static int mtk_pinconf_get(struct pinctrl_dev *pctldev,
>  		}
>  
>  		err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_SMT, &ret);
> +		if (!ret)
> +			err = -EINVAL;

In this function "ret" contains a mix of different data depending on
what the param is.  It's not always clear what "ret" means from one
line to the next.  I think it would be more clear to say
if (ret == MTK_DISABLE) in this case...

(I'm sorry to the list for sending so many nit picks today).

regards,
dan carpenter