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authorJohan Adolfsson <johan.adolfsson@axis.com>2025-06-17 12:23:54 +0200
committerLee Jones <lee@kernel.org>2025-06-27 13:58:31 +0100
commit2e84a5e5374232e6f356ce5c079a5658d7e4af2c (patch)
treebde08603e59c6265e8aa3db432fcd736336a1636
parent6012ce6b30567aa8ec8dc5b648b7841f9f74ca7c (diff)
leds: leds-lp50xx: Handle reg to get correct multi_index
mc_subled used for multi_index needs well defined array indexes, to guarantee the desired result, use reg for that. If devicetree child nodes is processed in random or reverse order you may end up with multi_index "blue green red" instead of the expected "red green blue". If user space apps uses multi_index to deduce how to control the leds they would most likely be broken without this patch if devicetree processing is reversed (which it appears to be). arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-fuji.dts has reg set but I don't see how it can have worked without this change. If reg is not set, an error is returned, If reg is out of range, an error is returned. reg within led child nodes starts with 0, to map to the iout in each bank. Signed-off-by: Johan Adolfsson <johan.adolfsson@axis.com> Reviewed-by: Jacek Anaszewski <jacek.anaszewski@gmail.com> Link: https://lore.kernel.org/r/20250617-led-fix-v7-1-cdbe8efc88fa@axis.com Signed-off-by: Lee Jones <lee@kernel.org>
-rw-r--r--drivers/leds/leds-lp50xx.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/leds/leds-lp50xx.c b/drivers/leds/leds-lp50xx.c
index 02cb1565a9fb..94f8ef6b482c 100644
--- a/drivers/leds/leds-lp50xx.c
+++ b/drivers/leds/leds-lp50xx.c
@@ -476,6 +476,7 @@ static int lp50xx_probe_dt(struct lp50xx *priv)
return -ENOMEM;
fwnode_for_each_child_node(child, led_node) {
+ int multi_index;
ret = fwnode_property_read_u32(led_node, "color",
&color_id);
if (ret) {
@@ -483,8 +484,16 @@ static int lp50xx_probe_dt(struct lp50xx *priv)
dev_err(priv->dev, "Cannot read color\n");
return ret;
}
+ ret = fwnode_property_read_u32(led_node, "reg", &multi_index);
+ if (ret != 0) {
+ dev_err(priv->dev, "reg must be set\n");
+ return -EINVAL;
+ } else if (multi_index >= LP50XX_LEDS_PER_MODULE) {
+ dev_err(priv->dev, "reg %i out of range\n", multi_index);
+ return -EINVAL;
+ }
- mc_led_info[num_colors].color_index = color_id;
+ mc_led_info[multi_index].color_index = color_id;
num_colors++;
}