Re: [PATCH v1 3/3] leds: aat1290: Add support for AAT1270 Current Regulator for Flash LEDs
From: Jacek Anaszewski
Date: Sun Oct 11 2026 - 12:01:57 EST
Hi Svyatoslav,
On 10/7/26 10:54 AM, Svyatoslav Ryhel wrote:
The AAT1270 is quite similar to the AAT1290, but it does not support the
Advanced Simple Serial Control (AS2C) used in the AAT1290. The AAT1270
uses an earlier version of AS2C, namely Simple Serial Control, which lacks
address-sending capabilities.
Differentiate the chips by using a description structure with a flag to
indicate if AS2C is supported, placing all AS2C-only features under a
conditional check.
Signed-off-by: Svyatoslav Ryhel <clamor95@xxxxxxxxx>
---
drivers/leds/flash/leds-aat1290.c | 66 ++++++++++++++++++++++---------
1 file changed, 47 insertions(+), 19 deletions(-)
diff --git a/drivers/leds/flash/leds-aat1290.c b/drivers/leds/flash/leds-aat1290.c
index 49251cfd33509..773cdcc73a9e1 100644
--- a/drivers/leds/flash/leds-aat1290.c
+++ b/drivers/leds/flash/leds-aat1290.c
@@ -43,9 +43,6 @@
#define AAT1290_FLASH_TM_NUM_LEVELS 16
#define AAT1290_MM_CURRENT_SCALE_SIZE 15
-#define AAT1290_NAME "aat1290"
-
-
struct aat1290_led_config_data {
/* maximum LED current in movie mode */
u32 max_mm_current;
@@ -59,6 +56,13 @@ struct aat1290_led_config_data {
enum led_brightness max_brightness;
};
+struct aat1290_led_chip_info {
+ /* led controller name */
+ const char *name;
+ /* Advanced Simple Serial Control support */
+ bool as2c;
+};
+
struct aat1290_led {
/* platform device data */
struct platform_device *pdev;
@@ -74,6 +78,10 @@ struct aat1290_led {
struct gpio_desc *gpio_fl_en;
/* EN|SET pin */
struct gpio_desc *gpio_en_set;
+
+ /* led controller description */
+ const struct aat1290_led_chip_info *info;
+
/* movie mode current scale */
int *mm_current_scale;
/* device mode */
@@ -101,15 +109,17 @@ static void aat1290_as2cwire_write(struct aat1290_led *led, int addr, int value)
udelay(AAT1290_FLEN_OFF_DELAY_TIME_US);
- /* write address */
- for (i = 0; i < addr; ++i) {
- udelay(AAT1290_EN_SET_TICK_TIME_US);
- gpiod_direction_output(led->gpio_en_set, 0);
- udelay(AAT1290_EN_SET_TICK_TIME_US);
- gpiod_direction_output(led->gpio_en_set, 1);
- }
+ if (led->info->as2c) {
+ /* write address */
+ for (i = 0; i < addr; ++i) {
+ udelay(AAT1290_EN_SET_TICK_TIME_US);
+ gpiod_direction_output(led->gpio_en_set, 0);
+ udelay(AAT1290_EN_SET_TICK_TIME_US);
+ gpiod_direction_output(led->gpio_en_set, 1);
+ }
- usleep_range(AAT1290_LATCH_TIME_MIN_US, AAT1290_LATCH_TIME_MAX_US);
+ usleep_range(AAT1290_LATCH_TIME_MIN_US, AAT1290_LATCH_TIME_MAX_US);
+ }
/* write data */
for (i = 0; i < value; ++i) {
@@ -150,16 +160,18 @@ static int aat1290_led_brightness_set(struct led_classdev *led_cdev,
led->movie_mode = false;
} else {
if (!led->movie_mode) {
- aat1290_as2cwire_write(led,
- AAT1290_MM_CURRENT_RATIO_ADDR,
- AAT1290_MM_TO_FL_1_92);
+ if (led->info->as2c)
+ aat1290_as2cwire_write(led,
+ AAT1290_MM_CURRENT_RATIO_ADDR,
+ AAT1290_MM_TO_FL_1_92);
In AAT1270 the Maximum Movie to Flash Mode Current Ratio is constant
and set to 1/7.3, whereas for AAT1290 we alter it to 1/1.92 here.
This is taken into account while calculating max_mm_current in
init_mm_current_scale(), where AAT1290_MAX_MM_CURRENT definition is
used, which is based on AAT1290_MM_TO_FL_RATIO (1000 / 1920).
Obviously it would have to be changed to 1000 / 7300 for AAT1270,
for the calculations between brightness levels and microamperes for
V4L2 Flash interface to work properly for this controller.
led->movie_mode = true;
}
aat1290_as2cwire_write(led, AAT1290_MOVIE_MODE_CURRENT_ADDR,
AAT1290_MAX_MM_CURR_PERCENT_0 - brightness);
- aat1290_as2cwire_write(led, AAT1290_MOVIE_MODE_CONFIG_ADDR,
- AAT1290_MOVIE_MODE_ON);
+ if (led->info->as2c)
+ aat1290_as2cwire_write(led, AAT1290_MOVIE_MODE_CONFIG_ADDR,
+ AAT1290_MOVIE_MODE_ON);
}
mutex_unlock(&led->lock);
@@ -178,7 +190,8 @@ static int aat1290_led_flash_strobe_set(struct led_classdev_flash *fled_cdev,
mutex_lock(&led->lock);
if (state) {
- aat1290_set_flash_safety_timer(led, timeout->val);
+ if (led->info->as2c)
+ aat1290_set_flash_safety_timer(led, timeout->val);
AAT1290 has the capability of setting flash safety timer timeout, not
like AAT1270, for which this is controlled solely by the discrete
elements, basing on the formula T = 21.5s/µF · CT. This needs to be
reflected both in the DT bindings and in the
aat1290_init_flash_timeout(), where the minimum value should be also
fixed for AAT1270.
gpiod_direction_output(led->gpio_fl_en, 1);
} else {
gpiod_direction_output(led->gpio_fl_en, 0);
@@ -475,6 +488,10 @@ static int aat1290_led_probe(struct platform_device *pdev)
fled_cdev->ops = &flash_ops;
led_cdev = &fled_cdev->led_cdev;
+ led->info = device_get_match_data(dev);
+ if (!led->info)
+ return -ENODEV;
+
ret = aat1290_led_get_configuration(led, &led_cfg, &sub_node);
if (ret < 0)
return ret;
@@ -489,7 +506,7 @@ static int aat1290_led_probe(struct platform_device *pdev)
aat1290_init_flash_timeout(led, &led_cfg);
init_data.fwnode = of_fwnode_handle(sub_node);
- init_data.devicename = AAT1290_NAME;
+ init_data.devicename = led->info->name;
/* Register LED Flash class device */
ret = led_classdev_flash_register_ext(&pdev->dev, fled_cdev,
@@ -528,8 +545,19 @@ static void aat1290_led_remove(struct platform_device *pdev)
mutex_destroy(&led->lock);
}
+static const struct aat1290_led_chip_info aat1290_info = {
+ .name = "aat1290",
+ .as2c = true,
+};
+
+static const struct aat1290_led_chip_info aat1270_info = {
+ .name = "aat1270",
+ .as2c = false,
+};
+
static const struct of_device_id aat1290_led_dt_match[] = {
- { .compatible = "skyworks,aat1290" },
+ { .compatible = "skyworks,aat1290", .data = &aat1290_info },
+ { .compatible = "skyworks,aat1270", .data = &aat1270_info },
{},
};
MODULE_DEVICE_TABLE(of, aat1290_led_dt_match);
--
Best regards,
Jacek Anaszewski