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leds: lm3601x: Calculate max_brightness and brightness properly

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The torch_current_max should be checked not exceeding the upper bound.
If it does, throw a warning message and set to LM3601X_MAX_TORCH_I_UA.

LM3601x torch brigthness register (LM3601X_LED_TORCH_REG) takes 0 as the
minimum output (2.4 mA). However, 0 of led_brightness means LED_OFF.
Adding a -1 offset to brightness before writing to brightness
register, so when users write minimum brightness (1), it sets lm3601x
output the minimum.

Signed-off-by: Jack Chen <zenghuchen@google.com>
Link: https://lore.kernel.org/r/20240704191500.766846-1-zenghuchen@google.com
Signed-off-by: Lee Jones <lee@kernel.org>
This commit is contained in:
Jack Chen 2024-07-04 15:15:00 -04:00 committed by Lee Jones
parent 8400291e28
commit b5a7fc286c
1 changed files with 12 additions and 3 deletions
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13
drivers/leds/flash/leds-lm3601x.c
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@ -190,7 +190,7 @@ static int lm3601x_brightness_set(struct led_classdev *cdev,
goto out;
}
ret = regmap_write(led->regmap, LM3601X_LED_TORCH_REG, brightness);
ret = regmap_write(led->regmap, LM3601X_LED_TORCH_REG, brightness - 1);
if (ret < 0)
goto out;
@ -341,7 +341,8 @@ static int lm3601x_register_leds(struct lm3601x_led *led,
led_cdev = &led->fled_cdev.led_cdev;
led_cdev->brightness_set_blocking = lm3601x_brightness_set;
led_cdev->max_brightness = DIV_ROUND_UP(led->torch_current_max,
led_cdev->max_brightness =
DIV_ROUND_UP(led->torch_current_max - LM3601X_MIN_TORCH_I_UA + 1,
LM3601X_TORCH_REG_DIV);
led_cdev->flags |= LED_DEV_CAP_FLASH;
@ -386,6 +387,14 @@ static int lm3601x_parse_node(struct lm3601x_led *led,
goto out_err;
}
if (led->torch_current_max > LM3601X_MAX_TORCH_I_UA) {
dev_warn(&led->client->dev,
"Max torch current set too high (%d vs %d)\n",
led->torch_current_max,
LM3601X_MAX_TORCH_I_UA);
led->torch_current_max = LM3601X_MAX_TORCH_I_UA;
}
ret = fwnode_property_read_u32(child, "flash-max-microamp",
&led->flash_current_max);
if (ret) {