[PATCH v6 6/9] leds: st1202: fix brightness having no effect while pattern mode is active

[Manuel Fombuena]

Once a hardware pattern is running (PATS=1), writing to the brightness
sysfs attribute only updates the ILED register. The visible output is
ILED x Pattern_PWM / 4095, so the change has little effect and the LED
never returns to steady static operation as the user expects.

The LED1202 has a single global sequencer shared across all channels.
Stopping it in brightness_set() to force static mode would halt running
patterns on all other active LEDs.

Instead, set all 8 PWM slots for the channel to ST1202_PATTERN_PWM_FULL
before writing ILED. With every step at full duty cycle, the output is
ILED x FULL / 4095 = ILED regardless of the sequencer state, without
disturbing other channels.

This also enables basic LED operation without the pattern trigger: with
the trigger set to none, the brightness sysfs attribute fully controls
the LED as a simple on/off device.

Fixes: 259230378c65 ("leds: Add LED1202 I2C driver")
Signed-off-by: Manuel Fombuena <fombuena@xxxxxxxxxxx>
Assisted-by: Claude:claude-sonnet-4-6
---
 drivers/leds/leds-st1202.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/leds/leds-st1202.c b/drivers/leds/leds-st1202.c
index b8a571282900..4909985ade04 100644
--- a/drivers/leds/leds-st1202.c
+++ b/drivers/leds/leds-st1202.c
@@ -136,6 +136,8 @@ static void st1202_brightness_set(struct led_classdev *led_cdev,
 
 	guard(mutex)(&chip->lock);
 
+	for (int patt = 0; patt < ST1202_MAX_PATTERNS; patt++)
+		st1202_pwm_pattern_write(chip, led->led_num, patt, ST1202_PATTERN_PWM_FULL);
 	st1202_write_reg(chip, ST1202_ILED_REG0 + led->led_num, value);
 }
 
-- 
2.55.0