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leds: st1202: Cap the channel current in st1202_led_set()

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st1202_led_set() writes the requested brightness straight into the 8-bit
channel current register. The LED core limits brightness to
max_brightness, which comes from the device tree max-brightness property
and has no upper bound, so on a board declaring more than 255 a
brightness of 256 reaches the register as 0 and turns the LED off, and
larger values wrap around.

Cap the value at U8_MAX, the width of the register, so anything above it
drives the channel at full current. The pattern and blink paths already
cap the current they program the same way.

Fixes: 259230378c ("leds: Add LED1202 I2C driver")
Signed-off-by: Manuel Fombuena <fombuena@outlook.com>
Assisted-by: LLM
Link: https://patch.msgid.link/GV1PR08MB8497C60D1D2921DD0384926FC5BA2@GV1PR08MB8497.eurprd08.prod.outlook.com
Signed-off-by: Lee Jones <lee@kernel.org>
This commit is contained in:
Manuel Fombuena 2026-09-15 13:48:22 +01:00 committed by Lee Jones
parent 865d81a986
commit ca81ea1085
1 changed files with 2 additions and 1 deletions
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3
drivers/leds/leds-st1202.c
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@ -207,7 +207,8 @@ static int st1202_led_set(struct led_classdev *ldev, enum led_brightness value)
return ret;
}
ret = st1202_write_reg(chip, ST1202_ILED_REG0 + led->led_num, value);
ret = st1202_write_reg(chip, ST1202_ILED_REG0 + led->led_num,
min_t(unsigned int, value, U8_MAX));
if (ret)
return ret;