[2/2] gpio: use "asserted" and "deasserted" instead of "high" and "low"

Message ID 20210503210526.43455-2-u.kleine-koenig@pengutronix.de
State New
Headers show
Series
  • Untitled series #124446
Related show

Commit Message

Uwe Kleine-König May 3, 2021, 9:05 p.m.
For active-low GPIOs the currently available nomenclature requires
regular explaination to the non-enlightened folks, e.g. because a hog
defined as:

	someline {
		gpio-hog;
		gpios = <24 GPIO_ACTIVE_LOW>;
		output-high;
	}

results in the line being set to the physical low level.

So use the terms "asserted" and "deasserted" which are less ambigous and
keep the old names as synonyms. The above example can now be written as:

	someline {
		gpio-hog;
		gpios = <24 GPIO_ACTIVE_LOW>;
		output-asserted;
	}

where it is less surprising that the output is set to a low level.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/gpio/gpiolib-of.c     | 10 ++++++++--
 include/linux/gpio/consumer.h | 14 ++++++++++----
 2 files changed, 18 insertions(+), 6 deletions(-)

Patch

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index baf0153b7bca..89e852da6a61 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -624,10 +624,16 @@  static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
 
 	if (of_property_read_bool(np, "input"))
 		*dflags |= GPIOD_IN;
+	else if (of_property_read_bool(np, "output-deasserted"))
+		*dflags |= GPIOD_OUT_DEASSERTED;
+	else if (of_property_read_bool(np, "output-asserted"))
+		*dflags |= GPIOD_OUT_ASSERTED;
 	else if (of_property_read_bool(np, "output-low"))
-		*dflags |= GPIOD_OUT_LOW;
+		/* misleading alias for output-deasserted */
+		*dflags |= GPIOD_OUT_DEASSERTED;
 	else if (of_property_read_bool(np, "output-high"))
-		*dflags |= GPIOD_OUT_HIGH;
+		/* misleading alias for output-asserted */
+		*dflags |= GPIOD_OUT_ASSERTED;
 	else {
 		pr_warn("GPIO line %d (%pOFn): no hogging state specified, bailing out\n",
 			desc_to_gpio(desc), np);
diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h
index c73b25bc9213..b40cc19cf419 100644
--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -49,11 +49,17 @@  struct gpio_descs {
 enum gpiod_flags {
 	GPIOD_ASIS	= 0,
 	GPIOD_IN	= GPIOD_FLAGS_BIT_DIR_SET,
-	GPIOD_OUT_LOW	= GPIOD_FLAGS_BIT_DIR_SET | GPIOD_FLAGS_BIT_DIR_OUT,
-	GPIOD_OUT_HIGH	= GPIOD_FLAGS_BIT_DIR_SET | GPIOD_FLAGS_BIT_DIR_OUT |
+	GPIOD_OUT_DEASSERTED = GPIOD_FLAGS_BIT_DIR_SET | GPIOD_FLAGS_BIT_DIR_OUT,
+	GPIOD_OUT_ASSERTED = GPIOD_FLAGS_BIT_DIR_SET | GPIOD_FLAGS_BIT_DIR_OUT |
 			  GPIOD_FLAGS_BIT_DIR_VAL,
-	GPIOD_OUT_LOW_OPEN_DRAIN = GPIOD_OUT_LOW | GPIOD_FLAGS_BIT_OPEN_DRAIN,
-	GPIOD_OUT_HIGH_OPEN_DRAIN = GPIOD_OUT_HIGH | GPIOD_FLAGS_BIT_OPEN_DRAIN,
+	GPIOD_OUT_DEASSERTED_OPEN_DRAIN = GPIOD_OUT_DEASSERTED | GPIOD_FLAGS_BIT_OPEN_DRAIN,
+	GPIOD_OUT_ASSERTED_OPEN_DRAIN = GPIOD_OUT_ASSERTED | GPIOD_FLAGS_BIT_OPEN_DRAIN,
+
+	/* old names that are confusing in combination with active-low GPIOs */
+	GPIOD_OUT_LOW = GPIOD_OUT_DEASSERTED,
+	GPIOD_OUT_HIGH = GPIOD_OUT_ASSERTED,
+	GPIOD_OUT_LOW_OPEN_DRAIN = GPIOD_OUT_DEASSERTED_OPEN_DRAIN,
+	GPIOD_OUT_HIGH_OPEN_DRAIN = GPIOD_OUT_ASSERTED_OPEN_DRAIN,
 };
 
 #ifdef CONFIG_GPIOLIB