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Subject[PATCH v2 9/9] gpiolib: of: add a quirk for reset line polarity for Himax LCDs
Date
Existing DTS that use legacy (non-standard) property name for the reset
line "gpios-reset" also specify incorrect polarity (0 which maps to
"active high"). Add a quirk to force polarity to "active low" so that
once driver is converted to gpiod API that pays attention to line
polarity it will work properly.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
drivers/gpio/gpiolib-of.c | 36 ++++++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 805222a2e6bc..26d57465fec9 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -152,11 +152,47 @@ static void of_gpio_quirk_polarity(const struct device_node *np,
}
}

+/*
+ * This quirk does static polarity overrides in cases where existing
+ * DTS specified incorrect polarity.
+ */
+static void of_gpio_try_fixup_polarity(const struct device_node *np,
+ const char *propname,
+ enum of_gpio_flags *flags)
+{
+ static const struct {
+ const char *compatible;
+ const char *propname;
+ bool active_high;
+ } gpios[] = {
+#if !IS_ENABLED(CONFIG_LCD_HX8357)
+ /*
+ * Himax LCD controllers used incorrectly named
+ * "gpios-reset" property and also specified wrong
+ * polarity.
+ */
+ { "himax,hx8357", "gpios-reset", false },
+ { "himax,hx8369", "gpios-reset", false },
+#endif
+ };
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(gpios); i++) {
+ if (of_device_is_compatible(np, gpios[i].compatible) &&
+ !strcmp(propname, gpios[i].propname)) {
+ of_gpio_quirk_polarity(np, gpios[i].active_high, flags);
+ break;
+ }
+ }
+}
+
static void of_gpio_flags_quirks(const struct device_node *np,
const char *propname,
enum of_gpio_flags *flags,
int index)
{
+ of_gpio_try_fixup_polarity(np, propname, flags);
+
/*
* Some GPIO fixed regulator quirks.
* Note that active low is the default.
--
b4 0.11.0-dev-5166b

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