[PATCH 2/2] leds: syscon: Implement support for active-low property

From: Pali Rohár
Date: Thu Aug 18 2022 - 13:26:12 EST


This new active-low property specify that LED has inverted logic
(0 - enable LED, 1 - disable LED).

Signed-off-by: Pali Rohár <pali@xxxxxxxxxx>
---
drivers/leds/leds-syscon.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/leds/leds-syscon.c b/drivers/leds/leds-syscon.c
index 7eddb8ecb44e..5e605d8438e9 100644
--- a/drivers/leds/leds-syscon.c
+++ b/drivers/leds/leds-syscon.c
@@ -29,6 +29,7 @@ struct syscon_led {
struct regmap *map;
u32 offset;
u32 mask;
+ bool active_low;
bool state;
};

@@ -41,10 +42,10 @@ static void syscon_led_set(struct led_classdev *led_cdev,
int ret;

if (value == LED_OFF) {
- val = 0;
+ val = sled->active_low ? sled->mask : 0;
sled->state = false;
} else {
- val = sled->mask;
+ val = sled->active_low ? 0 : sled->mask;
sled->state = true;
}

@@ -85,6 +86,8 @@ static int syscon_led_probe(struct platform_device *pdev)
return -EINVAL;
if (of_property_read_u32(np, "mask", &sled->mask))
return -EINVAL;
+ if (of_find_property(np, "active-low", NULL))
+ sled->active_low = true;

state = of_get_property(np, "default-state", NULL);
if (state) {
@@ -95,17 +98,20 @@ static int syscon_led_probe(struct platform_device *pdev)
if (ret < 0)
return ret;
sled->state = !!(val & sled->mask);
+ if (sled->active_low)
+ sled->state = !sled->state;
} else if (!strcmp(state, "on")) {
sled->state = true;
ret = regmap_update_bits(map, sled->offset,
sled->mask,
- sled->mask);
+ sled->active_low ? 0 : sled->mask);
if (ret < 0)
return ret;
} else {
sled->state = false;
ret = regmap_update_bits(map, sled->offset,
- sled->mask, 0);
+ sled->mask,
+ sled->active_low ? sled->mask : 0);
if (ret < 0)
return ret;
}
--
2.20.1