gpio: of: Restrict enable-gpio quirk to regulator-gpio

From: Thierry Reding <treding@nvidia.com>

Commit 0e7d6f940164 ("gpio: of: Apply regulator-gpio quirk only to
enable-gpios") breaks the device tree ABI specified in the device tree
bindings for fixed regulators (compatible "regulator-fixed"). According
to these bindings the polarity of the GPIO is exclusively controlled by
the presence or absence of the enable-active-high property. As such the
polarity quirk implemented in of_gpio_flags_quirks() must be applied to
the GPIO specified for fixed regulators.

However, commit 0e7d6f940164 ("gpio: of: Apply regulator-gpio quirk only
to enable-gpios") restricted the quirk to the enable-gpios property for
fixed regulators as well, whereas according to the commit message itself
it should only apply to "regulator-gpio" compatible device tree nodes.

Fix this by actually implementing what the offending commit intended,
which is to ensure that the quirk is applied to the GPIO specified by
the "enable-gpio" property for the "regulator-gpio" bindings only.

This fixes a regression on Jetson TX1 where the fixed regulator for the
HDMI +5V pin relies on the flags quirk for the proper polarity.

Fixes: 0e7d6f940164 ("gpio: of: Apply regulator-gpio quirk only to enable-gpios")
Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/gpio/gpiolib-of.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

On 2/20/19 11:52 AM, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
> 
> Commit 0e7d6f940164 ("gpio: of: Apply regulator-gpio quirk only to
> enable-gpios") breaks the device tree ABI specified in the device tree
> bindings for fixed regulators (compatible "regulator-fixed"). According
> to these bindings the polarity of the GPIO is exclusively controlled by
> the presence or absence of the enable-active-high property. As such the
> polarity quirk implemented in of_gpio_flags_quirks() must be applied to
> the GPIO specified for fixed regulators.
> 
> However, commit 0e7d6f940164 ("gpio: of: Apply regulator-gpio quirk only
> to enable-gpios") restricted the quirk to the enable-gpios property for
> fixed regulators as well, whereas according to the commit message itself
> it should only apply to "regulator-gpio" compatible device tree nodes.
> 
> Fix this by actually implementing what the offending commit intended,
> which is to ensure that the quirk is applied to the GPIO specified by
> the "enable-gpio" property for the "regulator-gpio" bindings only.
> 
> This fixes a regression on Jetson TX1 where the fixed regulator for the
> HDMI +5V pin relies on the flags quirk for the proper polarity.
> 
> Fixes: 0e7d6f940164 ("gpio: of: Apply regulator-gpio quirk only to enable-gpios")
> Signed-off-by: Thierry Reding <treding@nvidia.com>
> ---
>  drivers/gpio/gpiolib-of.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
> index 1b4c741e0635..bddfc6102a50 100644
> --- a/drivers/gpio/gpiolib-of.c
> +++ b/drivers/gpio/gpiolib-of.c
> @@ -84,10 +84,10 @@ static void of_gpio_flags_quirks(struct device_node *np,
>  	 * Note that active low is the default.
>  	 */
>  	if (IS_ENABLED(CONFIG_REGULATOR) &&
> -	    !strcmp(propname, "enable-gpio") &&
>  	    (of_device_is_compatible(np, "regulator-fixed") ||
>  	     of_device_is_compatible(np, "reg-fixed-voltage") ||
> -	     of_device_is_compatible(np, "regulator-gpio"))) {
> +	     (of_device_is_compatible(np, "regulator-gpio") &&
> +	      strcmp(propname, "enable-gpio") == 0))) {
>  		/*
>  		 * The regulator GPIO handles are specified such that the
>  		 * presence or absence of "enable-active-high" solely controls

On R8A7795 Salvator-XS
Tested-by: Marek Vasut <marek.vasut@gmail.com>

On Wed, Feb 20, 2019 at 11:52 AM Thierry Reding
<thierry.reding@gmail.com> wrote:

> From: Thierry Reding <treding@nvidia.com>
>
> Commit 0e7d6f940164 ("gpio: of: Apply regulator-gpio quirk only to
> enable-gpios") breaks the device tree ABI specified in the device tree
> bindings for fixed regulators (compatible "regulator-fixed"). According
> to these bindings the polarity of the GPIO is exclusively controlled by
> the presence or absence of the enable-active-high property. As such the
> polarity quirk implemented in of_gpio_flags_quirks() must be applied to
> the GPIO specified for fixed regulators.
>
> However, commit 0e7d6f940164 ("gpio: of: Apply regulator-gpio quirk only
> to enable-gpios") restricted the quirk to the enable-gpios property for
> fixed regulators as well, whereas according to the commit message itself
> it should only apply to "regulator-gpio" compatible device tree nodes.
>
> Fix this by actually implementing what the offending commit intended,
> which is to ensure that the quirk is applied to the GPIO specified by
> the "enable-gpio" property for the "regulator-gpio" bindings only.
>
> This fixes a regression on Jetson TX1 where the fixed regulator for the
> HDMI +5V pin relies on the flags quirk for the proper polarity.
>
> Fixes: 0e7d6f940164 ("gpio: of: Apply regulator-gpio quirk only to enable-gpios")
> Signed-off-by: Thierry Reding <treding@nvidia.com>

Patch applied with Marek's tested-by, thanks for thorough commit
message and helping out in sorting out this mess we've built
up over the years.

Yours,
Linus Walleij