[PATCH v2 6/6] video: leds: backlight: lm3533: Support getting LED sources from DT

From: Svyatoslav Ryhel

Date: Thu May 28 2026 - 10:03:45 EST


Add Control Bank to HVLED/LVLED muxing support based on the led-sources
defined in the device tree.

Signed-off-by: Svyatoslav Ryhel <clamor95@xxxxxxxxx>
---
drivers/leds/leds-lm3533.c | 55 ++++++++++++++++++++++++++++-
drivers/video/backlight/lm3533_bl.c | 37 ++++++++++++++++++-
2 files changed, 90 insertions(+), 2 deletions(-)

diff --git a/drivers/leds/leds-lm3533.c b/drivers/leds/leds-lm3533.c
index d707d43d5526..07390bba9a48 100644
--- a/drivers/leds/leds-lm3533.c
+++ b/drivers/leds/leds-lm3533.c
@@ -7,6 +7,7 @@
* Author: Johan Hovold <jhovold@xxxxxxxxx>
*/

+#include <linux/bits.h>
#include <linux/module.h>
#include <linux/leds.h>
#include <linux/mfd/core.h>
@@ -26,6 +27,12 @@
#define LM3533_ALS_CHANNEL_LV_MIN 1
#define LM3533_ALS_CHANNEL_LV_MAX 2

+#define LM3533_REG_OUTPUT_CONF1 0x10
+#define OUTPUT_CONF1_MASK GENMASK(7, 2)
+#define OUTPUT_CONF1_SHIFT 2
+#define LM3533_REG_OUTPUT_CONF2 0x11
+#define OUTPUT_CONF2_MASK GENMASK(3, 0)
+#define OUTPUT_CONF2_SHIFT 6
#define LM3533_REG_CTRLBANK_BCONF_BASE 0x1b
#define LM3533_REG_PATTERN_ENABLE 0x28
#define LM3533_REG_PATTERN_LOW_TIME_BASE 0x71
@@ -53,6 +60,9 @@ struct lm3533_led {

u32 max_current;
u32 pwm;
+
+ int num_leds;
+ u32 leds[LM3533_LVCTRLBANK_MAX];
};


@@ -639,7 +649,33 @@ static const struct attribute_group *lm3533_led_attribute_groups[] = {

static int lm3533_led_setup(struct lm3533_led *led)
{
- int ret;
+ u32 output_cfg_shift = 0;
+ u32 output_cfg_val = 0;
+ int ret, i;
+
+ if (led->num_leds) {
+ for (i = 0; i < led->num_leds; i++) {
+ if (led->leds[i] > LM3533_LVCTRLBANK_MAX)
+ continue;
+
+ output_cfg_shift = led->leds[i] * 2;
+ output_cfg_val |= led->id << output_cfg_shift;
+ }
+
+ /* LVLED1, LVLED2 and LVLED3 */
+ ret = lm3533_update(led->lm3533, LM3533_REG_OUTPUT_CONF1,
+ output_cfg_val << OUTPUT_CONF1_SHIFT,
+ OUTPUT_CONF1_MASK);
+ if (ret)
+ return ret;
+
+ /* LVLED4 and LVLED5 */
+ ret = lm3533_update(led->lm3533, LM3533_REG_OUTPUT_CONF2,
+ output_cfg_val >> OUTPUT_CONF2_SHIFT,
+ OUTPUT_CONF2_MASK);
+ if (ret)
+ return ret;
+ }

ret = lm3533_ctrlbank_set_max_current(&led->cb, led->max_current);
if (ret)
@@ -714,6 +750,23 @@ static int lm3533_led_probe(struct platform_device *pdev)
led->pwm = 0;
device_property_read_u32(&pdev->dev, "ti,pwm-config-mask", &led->pwm);

+ led->num_leds = device_property_count_u32(&pdev->dev, "led-sources");
+
+ /*
+ * If led-sources property is not set then either this Control Bank uses
+ * its default LVLED or is not linked to any LVLED at all.
+ */
+ if (led->num_leds > 0 && led->num_leds <= LM3533_LVCTRLBANK_MAX) {
+ ret = device_property_read_u32_array(&pdev->dev, "led-sources",
+ led->leds, led->num_leds);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to get led-sources\n");
+ goto err_deregister;
+ }
+ } else {
+ led->num_leds = 0;
+ }
+
ret = lm3533_led_setup(led);
if (ret)
goto err_deregister;
diff --git a/drivers/video/backlight/lm3533_bl.c b/drivers/video/backlight/lm3533_bl.c
index c03d0d1667e4..82b46a531dd2 100644
--- a/drivers/video/backlight/lm3533_bl.c
+++ b/drivers/video/backlight/lm3533_bl.c
@@ -7,6 +7,7 @@
* Author: Johan Hovold <jhovold@xxxxxxxxx>
*/

+#include <linux/bits.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/mod_devicetable.h>
@@ -21,6 +22,8 @@
#define LM3533_HVCTRLBANK_COUNT 2
#define LM3533_BL_MAX_BRIGHTNESS 255

+#define LM3533_REG_OUTPUT_CONF1 0x10
+#define OUTPUT_CONF1_MASK GENMASK(1, 0)
#define LM3533_REG_CTRLBANK_AB_BCONF 0x1a
#define CTRLBANK_AB_BCONF_MODE(n) BIT(2 * (n) + 1)

@@ -34,6 +37,9 @@ struct lm3533_bl {
u32 max_current;
u32 pwm;
bool linear;
+
+ u32 num_leds;
+ u32 led_strings[LM3533_HVCTRLBANK_COUNT];
};


@@ -248,7 +254,8 @@ static struct attribute_group lm3533_bl_attribute_group = {
static int lm3533_bl_setup(struct lm3533_bl *bl)
{
int id = lm3533_bl_get_ctrlbank_id(bl);
- int ret;
+ u32 output_cfg_val = 0;
+ int ret, i;

ret = lm3533_update(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF,
bl->linear ? CTRLBANK_AB_BCONF_MODE(id) : 0,
@@ -256,6 +263,16 @@ static int lm3533_bl_setup(struct lm3533_bl *bl)
if (ret)
return ret;

+ if (bl->num_leds) {
+ for (i = 0; i < bl->num_leds; i++)
+ output_cfg_val |= id << bl->led_strings[i];
+
+ ret = lm3533_update(bl->lm3533, LM3533_REG_OUTPUT_CONF1,
+ output_cfg_val, OUTPUT_CONF1_MASK);
+ if (ret)
+ return ret;
+ }
+
ret = lm3533_ctrlbank_set_max_current(&bl->cb, bl->max_current);
if (ret)
return ret;
@@ -329,6 +346,24 @@ static int lm3533_bl_probe(struct platform_device *pdev)
bl->linear = device_property_read_bool(&pdev->dev,
"ti,linear-mapping-mode");

+ bl->num_leds = device_property_count_u32(&pdev->dev, "led-sources");
+
+ /*
+ * If led-sources property is not set then either this Control Bank uses
+ * its default HVLED or is not linked to any HVLED at all.
+ */
+ if (bl->num_leds > 0 && bl->num_leds <= LM3533_HVCTRLBANK_COUNT) {
+ ret = device_property_read_u32_array(&pdev->dev, "led-sources",
+ bl->led_strings,
+ bl->num_leds);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to get led-sources\n");
+ goto err_sysfs_remove;
+ }
+ } else {
+ bl->num_leds = 0;
+ }
+
ret = lm3533_bl_setup(bl);
if (ret)
return ret;
--
2.51.0