[PATCH v2] gpiolib: of: fix lookup quirk for MIPS Lantiq

[PATCH v2] gpiolib: of: fix lookup quirk for MIPS Lantiq

[Dmitry Torokhov]

As it turns out, there is a large number of out-of-tree DTSes (in
OpenWrt project) that used to specify incorrect (active high) polarity
for the Lantiq reset GPIO, so to keep compatibility while they are
being updated a quirk for force the polarity low is needed. Luckily
these old DTSes used nonstandard name for the property ("gpio-reset" vs
"reset-gpios") so the quirk will not hurt if there are any new devices
that need inverted polarity as they can specify the right polarity in
their DTS when using the standard "reset-gpios" property.

Additionally the condition to enable the transition from standard to
non-standard reset GPIO property name was inverted and the replacement
name for the property was not correct. Fix this as well.

Fixes: fbbbcd177a27 ("gpiolib: of: add quirk for locating reset lines with legacy bindings")
Fixes: 90c2d2eb7ab5 ("MIPS: pci: lantiq: switch to using gpiod API")
Reported-by: Martin Schiller <ms@dev.tdt.de>
Acked-by: Martin Schiller <ms@dev.tdt.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---

v2: collected acked-by, rebased on top of gpio-fixes-for-v6.10-rc6 

 drivers/gpio/gpiolib-of.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index d75f6ee37028..38679cf1969f 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -202,6 +202,16 @@ static void of_gpio_try_fixup_polarity(const struct device_node *np,
 		 * helper, and be consistent with what other drivers do.
 		 */
 		{ "qi,lb60",		"rb-gpios",	true },
+#endif
+#if IS_ENABLED(CONFIG_PCI_LANTIQ)
+		/*
+		 * According to the PCI specification, the RST# pin is an
+		 * active-low signal. However, most of the device trees that
+		 * have been widely used for a long time incorrectly describe
+		 * reset GPIO as active-high, and were also using wrong name
+		 * for the property.
+		 */
+		{ "lantiq,pci-xway",	"gpio-reset",	false },
 #endif
 	};
 	unsigned int i;
@@ -504,9 +514,9 @@ static struct gpio_desc *of_find_gpio_rename(struct device_node *np,
 		{ "reset",	"reset-n-io",	"marvell,nfc-uart" },
 		{ "reset",	"reset-n-io",	"mrvl,nfc-uart" },
 #endif
-#if !IS_ENABLED(CONFIG_PCI_LANTIQ)
+#if IS_ENABLED(CONFIG_PCI_LANTIQ)
 		/* MIPS Lantiq PCI */
-		{ "reset",	"gpios-reset",	"lantiq,pci-xway" },
+		{ "reset",	"gpio-reset",	"lantiq,pci-xway" },
 #endif
 
 		/*
-- 
2.45.2.803.g4e1b14247a-goog

-- 
Dmitry

Re: [PATCH v2] gpiolib: of: fix lookup quirk for MIPS Lantiq

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>


On Mon, 01 Jul 2024 10:38:50 -0700, Dmitry Torokhov wrote:
> As it turns out, there is a large number of out-of-tree DTSes (in
> OpenWrt project) that used to specify incorrect (active high) polarity
> for the Lantiq reset GPIO, so to keep compatibility while they are
> being updated a quirk for force the polarity low is needed. Luckily
> these old DTSes used nonstandard name for the property ("gpio-reset" vs
> "reset-gpios") so the quirk will not hurt if there are any new devices
> that need inverted polarity as they can specify the right polarity in
> their DTS when using the standard "reset-gpios" property.
> 
> [...]

Applied, thanks!

[1/1] gpiolib: of: fix lookup quirk for MIPS Lantiq
      commit: 3645ffaf2b334abaf5f53e5ca0f47465d91e69d2

Best regards,
-- 
Bartosz Golaszewski <bartosz.golaszewski@linaro.org>