[PATCH v6 0/2] Add Support for LTC3220 18 Channel LED Driver

[PATCH v6 0/2] Add Support for LTC3220 18 Channel LED Driver

[Edelweise Escala]

The LTC3220/LTC3220-1 is a multi-display LED driver, which contains a
high-efficiency, low-noise charge pump to provide power to up to
18 LED current sources. The LEDs are individually configurable to
64-step linear brightness control, blinking and gradation control
via 2-wire I2C interface. The blinking and gradation configuration
is shared across all LED.

LTC3220 has a quick write function which allows changing the brightness
on all LEDS simultaneously when the brightness is changed on led 1.
For this leds are aggregated in the device tree and on probe we check
if led-sources exist to enable quick write. 
We would like to know if this approach is alright?
Another way we might want to know is, is it alright to just make a
virtual led for the quick write function. Changing brightness on 
the virtual led will change the brightness for all.

Signed-off-by: Edelweise Escala <edelweise.escala@analog.com>
---
Changes in v6:
- Fix commit message
- Add manufacturer on Kconfig and improve description
- Rearrange register map and bitmask and improve naming
- Use regmap, also use update bits of regmap to avoid unnecessary
  structs
- Alignment and spacing fixes
- Use Define for magic naumbers
- Fix blink calculation
- Add comments on aggregated LED
- Fix variable name to something more understandable like i to led_index
- Link to v5: https://lore.kernel.org/r/20260126-ltc3220-driver-v5-0-152a30e98ab7@analog.com

Changes in v5:
- Missed rename on bindings filename in MAINTAINERS file
- Link to v4: https://lore.kernel.org/linux-leds/20260126-ltc3220-driver-v4-0-c59517206c24@analog.com

Changes in v4:
- Rename leds-ltc3220.yaml to adi,ltc3220.yaml
- Add Reviewed-by: Conor Dooley <conor.dooley@microchip.com> on
  adi,ltc3220.yaml
Other V1 comments I think already addressed
- Subject commit message was already changed to match hardware
- Fixed wrapping after description
- Dropped "Bindings for" in descriptions and improved description to match hardware
- Dropped adi,ltc3220-1
- Dropped redundant description on reset-gpios
- Dropped adi,force-cpo-level
- Dropped adi,quick-write in favor of aggregated LED
- Used consistent quotes ^led@([1-9]|1[0-8])$
- Fixed wrapping on error messages

- Link to v3: https://lore.kernel.org/r/20260120-ltc3220-driver-v3-0-fef612ec4faa@analog.com

Changes in v3:
- Dropped quick-write on bindings and added aggregated led instead.
- Add aggregated led example.
- Modify quick write to check if there is aggregated led, if there is
  aggregated led enable quick write.
- Use DEFINE_SIMPLE_DEV_PM_OPS instead of SIMPLE_DEV_PM_OPS.
- Link to v2: https://lore.kernel.org/r/20260112-ltc3220-driver-v2-0-d043058fc4df@analog.com

Changes in v2:
leds-ltc3220.yaml changes
- Fix wrapping on description
- Improve description and commit messge to describe hardware
- Drop ltc3220-1
- Drop charge pump
ltc3220.c changes
- Fix wrapping
- Drop ltc3220-1
- Drop devname_mandatory
- Link to v1: https://lore.kernel.org/r/20260106-ltc3220-driver-v1-0-73601d6f1649@analog.com

---
Edelweise Escala (2):
      dt-bindings: leds: Add LTC3220 18 channel LED Driver
      leds: ltc3220: Add Support for LTC3220 18 channel LED Driver

 .../devicetree/bindings/leds/adi,ltc3220.yaml      | 120 ++++++
 MAINTAINERS                                        |   8 +
 drivers/leds/Kconfig                               |  12 +
 drivers/leds/Makefile                              |   1 +
 drivers/leds/leds-ltc3220.c                        | 418 +++++++++++++++++++++
 5 files changed, 559 insertions(+)
---
base-commit: 8856d7fe1758937ac528770f552ec58c388c255b
change-id: 20260106-ltc3220-driver-f9ab6cc9d1e4

Best regards,
-- 
Edelweise Escala <edelweise.escala@analog.com>

[PATCH v6 1/2] dt-bindings: leds: Add LTC3220 18 channel LED Driver

[Edelweise Escala]

LTC3220 is a multi-display LED driver with I2C interface.
The LTC3220 provides individual brightness control (64-step),
blinking, and gradation features for up to 18 LED outputs.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Edelweise Escala <edelweise.escala@analog.com>
---
 .../devicetree/bindings/leds/adi,ltc3220.yaml      | 120 +++++++++++++++++++++
 MAINTAINERS                                        |   7 ++
 2 files changed, 127 insertions(+)

diff --git a/Documentation/devicetree/bindings/leds/adi,ltc3220.yaml b/Documentation/devicetree/bindings/leds/adi,ltc3220.yaml
new file mode 100644
index 000000000000..62f760d517aa
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/adi,ltc3220.yaml
@@ -0,0 +1,120 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/adi,ltc3220.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices LTC3220 LED Driver
+
+maintainers:
+  - Edelweise Escala <edelweise.escala@analog.com>
+
+description:
+  The LTC3220 is a multi-display LED driver, which contains a high-efficiency,
+  low-noise charge pump to provide power to up to 18 LED current sources.
+  The LEDs are individually configurable to 64-step linear brightness control,
+  blinking and gradation control via 2-wire I2C interface.
+
+  For more product information please see the link below
+    https://www.analog.com/en/products/ltc3220.html
+
+properties:
+  compatible:
+    const: adi,ltc3220
+
+  reg:
+    maxItems: 1
+
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+  reset-gpios:
+    maxItems: 1
+
+patternProperties:
+  '^led@([1-9]|1[0-8])$':
+    type: object
+    $ref: /schemas/leds/common.yaml#
+    unevaluatedProperties: false
+    properties:
+      reg:
+        description:
+          Output channel for the LED (1-18 maps to LED outputs D1-D18).
+          For aggregated LED control, define only one LED node with reg = <1>
+          and use led-sources to list all controlled outputs. Only reg 1 should
+          be present when using led-sources.
+        minimum: 1
+        maximum: 18
+
+    required:
+      - reg
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    // Independent LEDs
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/leds/common.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        led-controller@1c {
+            compatible = "adi,ltc3220";
+            reg = <0x1c>;
+            #address-cells = <1>;
+            #size-cells = <0>;
+            reset-gpios = <&gpio 17 GPIO_ACTIVE_LOW>;
+
+            led@1 {
+                reg = <1>;
+                function = LED_FUNCTION_INDICATOR;
+                function-enumerator = <1>;
+            };
+
+            led@2 {
+                reg = <2>;
+                function = LED_FUNCTION_INDICATOR;
+                function-enumerator = <2>;
+            };
+
+            led@3 {
+                reg = <3>;
+                function = LED_FUNCTION_INDICATOR;
+                function-enumerator = <3>;
+            };
+        };
+    };
+
+  - |
+    // Aggregated LED
+    #include <dt-bindings/leds/common.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        led-controller@1c {
+            compatible = "adi,ltc3220";
+            reg = <0x1c>;
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            led@1 {
+                reg = <1>;
+                led-sources = <1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18>;
+                function = LED_FUNCTION_BACKLIGHT;
+            };
+        };
+    };
+
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index 327d74ca7ecb..5c10cc3e3022 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14955,6 +14955,13 @@ W:	https://ez.analog.com/linux-software-drivers
 F:	Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
 F:	drivers/iio/temperature/ltc2983.c
 
+LTC3220 LED DRIVER
+M:	Edelweise Escala <edelweise.escala@analog.com>
+L:	linux-leds@vger.kernel.org
+S:	Maintained
+W:	https://ez.analog.com/linux-software-drivers
+F:	Documentation/devicetree/bindings/leds/adi,ltc3220.yaml
+
 LTC4282 HARDWARE MONITOR DRIVER
 M:	Nuno Sa <nuno.sa@analog.com>
 L:	linux-hwmon@vger.kernel.org

-- 
2.43.0

[PATCH v6 2/2] leds: ltc3220: Add Support for LTC3220 18 channel LED Driver

[Edelweise Escala]

Add driver for the LTC3220 18-channel LED driver
with I2C interface, individual brightness control, and hardware-assisted
blink/gradation features.

Signed-off-by: Edelweise Escala <edelweise.escala@analog.com>
---
 MAINTAINERS                 |   1 +
 drivers/leds/Kconfig        |  12 ++
 drivers/leds/Makefile       |   1 +
 drivers/leds/leds-ltc3220.c | 418 ++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 432 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 5c10cc3e3022..7467537938bf 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14961,6 +14961,7 @@ L:	linux-leds@vger.kernel.org
 S:	Maintained
 W:	https://ez.analog.com/linux-software-drivers
 F:	Documentation/devicetree/bindings/leds/adi,ltc3220.yaml
+F:	drivers/leds/leds-ltc3220.c
 
 LTC4282 HARDWARE MONITOR DRIVER
 M:	Nuno Sa <nuno.sa@analog.com>
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 597d7a79c988..f00cdc11c978 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -1001,6 +1001,18 @@ config LEDS_ST1202
 	  Say Y to enable support for LEDs connected to LED1202
 	  LED driver chips accessed via the I2C bus.
 
+config LEDS_LTC3220
+	tristate "LED Driver for Analog Devices Inc. LTC3220"
+	depends on I2C && LEDS_CLASS
+	help
+	  Say Y to enable support for the Analog Devices LTC3220
+	  18-channel LED controller with I2C interface.
+	  The driver supports individual LED brightness control (64 steps),
+	  hardware-assisted blinking and gradation effects.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called leds-ltc3220.
+
 config LEDS_TPS6105X
 	tristate "LED support for TI TPS6105X"
 	depends on LEDS_CLASS
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 8fdb45d5b439..5301568d9e00 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -61,6 +61,7 @@ obj-$(CONFIG_LEDS_LP8788)		+= leds-lp8788.o
 obj-$(CONFIG_LEDS_LP8860)		+= leds-lp8860.o
 obj-$(CONFIG_LEDS_LP8864)		+= leds-lp8864.o
 obj-$(CONFIG_LEDS_LT3593)		+= leds-lt3593.o
+obj-$(CONFIG_LEDS_LTC3220)		+= leds-ltc3220.o
 obj-$(CONFIG_LEDS_MAX5970)		+= leds-max5970.o
 obj-$(CONFIG_LEDS_MAX77650)		+= leds-max77650.o
 obj-$(CONFIG_LEDS_MAX77705)		+= leds-max77705.o
diff --git a/drivers/leds/leds-ltc3220.c b/drivers/leds/leds-ltc3220.c
new file mode 100644
index 000000000000..5e1f994cc35b
--- /dev/null
+++ b/drivers/leds/leds-ltc3220.c
@@ -0,0 +1,418 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * LTC3220 18-Channel LED Driver
+ *
+ * Copyright 2026 Analog Devices Inc.
+ *
+ * Author: Edelweise Escala <edelweise.escala@analog.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/leds.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+
+/* LTC3220 Registers */
+#define LTC3220_COMMAND_REG				0x00
+#define   LTC3220_QUICK_WRITE_MASK			BIT(0)
+#define   LTC3220_SHUTDOWN_MASK				BIT(3)
+
+#define LTC3220_ULED_REG(x)				(0x01 + (x))
+#define   LTC3220_LED_CURRENT_MASK			GENMASK(5, 0)
+#define   LTC3220_LED_MODE_MASK				GENMASK(7, 6)
+
+#define LTC3220_GRAD_BLINK_REG				0x13
+#define   LTC3220_GRADATION_MASK			GENMASK(2, 0)
+#define   LTC3220_GRADATION_DIRECTION_MASK		BIT(0)
+#define   LTC3220_GRADATION_PERIOD_MASK			GENMASK(2, 1)
+#define   LTC3220_BLINK_MASK				GENMASK(4, 3)
+
+#define LTC3220_NUM_LEDS				18
+
+#define LTC3220_GRADATION_START_VALUE			128
+#define LTC3220_GRADATION_RAMP_TIME_240MS		240
+#define LTC3220_GRADATION_RAMP_TIME_480MS		480
+
+#define LTC3220_BLINK_ON_156MS				156
+#define LTC3220_BLINK_ON_625MS				625
+#define LTC3220_BLINK_PERIOD_1250MS			1250
+#define LTC3220_BLINK_PERIOD_2500MS			2500
+
+#define LTC3220_BLINK_SHORT_ON_TIME			BIT(0)
+#define LTC3220_BLINK_LONG_PERIOD			BIT(1)
+
+enum ltc3220_blink_mode {
+	LTC3220_BLINK_MODE_625MS_1250MS,
+	LTC3220_BLINK_MODE_156MS_1250MS,
+	LTC3220_BLINK_MODE_625MS_2500MS,
+	LTC3220_BLINK_MODE_156MS_2500MS
+};
+
+enum ltc3220_gradation_mode {
+	LTC3220_GRADATION_MODE_DISABLED,
+	LTC3220_GRADATION_MODE_240MS_RAMP_TIME,
+	LTC3220_GRADATION_MODE_480MS_RAMP_TIME,
+	LTC3220_GRADATION_MODE_960MS_RAMP_TIME
+};
+
+static const struct regmap_config ltc3220_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = LTC3220_GRAD_BLINK_REG,
+};
+
+struct ltc3220_uled_cfg {
+	struct ltc3220_state *ltc3220_state;
+	struct led_classdev led_cdev;
+	u8 reg_value;
+	u8 led_index;
+};
+
+struct ltc3220_state {
+	struct ltc3220_uled_cfg uled_cfg[LTC3220_NUM_LEDS];
+	struct regmap *regmap;
+	bool is_aggregated;
+};
+
+static int ltc3220_shutdown(struct ltc3220_state *ltc3220_state)
+{
+	return regmap_update_bits(ltc3220_state->regmap, LTC3220_COMMAND_REG,
+				  LTC3220_SHUTDOWN_MASK, LTC3220_SHUTDOWN_MASK);
+}
+
+static int ltc3220_resume_from_shutdown(struct ltc3220_state *ltc3220_state)
+{
+	return regmap_update_bits(ltc3220_state->regmap, LTC3220_COMMAND_REG,
+				  LTC3220_SHUTDOWN_MASK, 0);
+}
+
+/*
+ * Set LED brightness and mode.
+ * The brightness value determines both the LED current and operating mode:
+ * 0-63:    Normal mode - LED current from 0-63 (off to full brightness)
+ * 64-127:  Blink mode - LED blinks with current level (brightness - 64)
+ * 128-191: Gradation mode - LED gradually changes brightness (brightness - 128)
+ * 192-255: GPO mode - LED operates as general purpose output (brightness - 192)
+ */
+static int ltc3220_set_led_data(struct led_classdev *led_cdev,
+				enum led_brightness brightness)
+{
+	struct ltc3220_state *ltc3220_state;
+	struct ltc3220_uled_cfg *uled_cfg;
+	int ret;
+	int i;
+
+	uled_cfg = container_of(led_cdev, struct ltc3220_uled_cfg, led_cdev);
+	ltc3220_state = uled_cfg->ltc3220_state;
+
+	ret = regmap_write(ltc3220_state->regmap, LTC3220_ULED_REG(uled_cfg->led_index),
+			   brightness);
+	if (ret < 0)
+		return ret;
+
+	uled_cfg->reg_value = brightness;
+
+	/*
+	 * When aggregated LED mode is enabled, writing to LED 1 updates all
+	 * LEDs simultaneously via quick-write mode. Update cached values for
+	 * all LEDs to reflect the synchronized state.
+	 * See Documentation/devicetree/bindings/leds/adi,ltc3220.yaml for how
+	 * to configure aggregated LED mode.
+	 */
+	if (ltc3220_state->is_aggregated && uled_cfg->led_index == 0) {
+		for (i = 0; i < LTC3220_NUM_LEDS; i++)
+			ltc3220_state->uled_cfg[i].reg_value = brightness;
+	}
+
+	return 0;
+}
+
+static enum led_brightness ltc3220_get_led_data(struct led_classdev *led_cdev)
+{
+	struct ltc3220_uled_cfg *uled_cfg = container_of(led_cdev,
+							 struct ltc3220_uled_cfg, led_cdev);
+
+	return uled_cfg->reg_value;
+}
+
+/*
+ * LTC3220 pattern support for hardware-assisted breathing/gradation.
+ * The hardware supports 3 gradation ramp time 240ms, 480ms, 960ms)
+ * and can ramp up or down.
+ *
+ * Pattern array interpretation:
+ *   pattern[0].brightness = start brightness (0-63)
+ *   pattern[0].delta_t = ramp time in milliseconds
+ *   pattern[1].brightness = end brightness (0-63)
+ *   pattern[1].delta_t = (optional, can be 0 or same as pattern[0].delta_t)
+ */
+static int ltc3220_pattern_set(struct led_classdev *led_cdev,
+			       struct led_pattern *pattern,
+			       u32 len, int repeat)
+{
+	struct ltc3220_uled_cfg *uled_cfg = container_of(led_cdev, struct ltc3220_uled_cfg,
+							 led_cdev);
+	struct ltc3220_state *ltc3220_state = uled_cfg->ltc3220_state;
+	u8 gradation_period;
+	u8 start_brightness;
+	u8 end_brightness;
+	u8 reg_val;
+	bool is_increasing;
+	int ret;
+
+	if (len != 2)
+		return -EINVAL;
+
+	start_brightness = pattern[0].brightness & LTC3220_LED_CURRENT_MASK;
+	end_brightness = pattern[1].brightness & LTC3220_LED_CURRENT_MASK;
+
+	is_increasing = end_brightness > start_brightness;
+
+	if (pattern[0].delta_t == 0)
+		gradation_period = LTC3220_GRADATION_MODE_DISABLED;
+	else if (pattern[0].delta_t <= LTC3220_GRADATION_RAMP_TIME_240MS)
+		gradation_period = LTC3220_GRADATION_MODE_240MS_RAMP_TIME;
+	else if (pattern[0].delta_t <= LTC3220_GRADATION_RAMP_TIME_480MS)
+		gradation_period = LTC3220_GRADATION_MODE_480MS_RAMP_TIME;
+	else
+		gradation_period = LTC3220_GRADATION_MODE_960MS_RAMP_TIME;
+
+	reg_val = FIELD_PREP(LTC3220_GRADATION_PERIOD_MASK, gradation_period);
+	reg_val |= FIELD_PREP(LTC3220_GRADATION_DIRECTION_MASK, is_increasing);
+
+	ret = regmap_update_bits(ltc3220_state->regmap, LTC3220_GRAD_BLINK_REG,
+				 LTC3220_GRADATION_MASK, reg_val);
+	if (ret < 0)
+		return ret;
+
+	ret = ltc3220_set_led_data(led_cdev, start_brightness);
+	if (ret < 0)
+		return ret;
+
+	return ltc3220_set_led_data(led_cdev, LTC3220_GRADATION_START_VALUE + end_brightness);
+}
+
+static int ltc3220_pattern_clear(struct led_classdev *led_cdev)
+{
+	struct ltc3220_uled_cfg *uled_cfg = container_of(led_cdev, struct ltc3220_uled_cfg,
+							 led_cdev);
+	struct ltc3220_state *ltc3220_state = uled_cfg->ltc3220_state;
+
+	return regmap_update_bits(ltc3220_state->regmap, LTC3220_GRAD_BLINK_REG,
+							  LTC3220_GRADATION_MASK, 0);
+}
+
+/*
+ * LTC3220 has a global blink configuration that affects all LEDs.
+ * This implementation allows per-LED blink requests, but the blink timing
+ * will be shared across all LEDs. The delay values are mapped to the
+ * hardware's discrete blink rates.
+ */
+static int ltc3220_blink_set(struct led_classdev *led_cdev,
+			     unsigned long *delay_on,
+			     unsigned long *delay_off)
+{
+	struct ltc3220_uled_cfg *uled_cfg = container_of(led_cdev, struct ltc3220_uled_cfg,
+							 led_cdev);
+	struct ltc3220_state *ltc3220_state = uled_cfg->ltc3220_state;
+	u8 blink_mode = 0;
+
+	if (*delay_on <= LTC3220_BLINK_ON_156MS)
+		blink_mode = LTC3220_BLINK_SHORT_ON_TIME;
+
+	if (*delay_on + *delay_off > LTC3220_BLINK_PERIOD_1250MS)
+		blink_mode |= LTC3220_BLINK_LONG_PERIOD;
+
+	switch (blink_mode) {
+	case LTC3220_BLINK_MODE_625MS_1250MS:
+		*delay_on = LTC3220_BLINK_ON_625MS;
+		*delay_off = LTC3220_BLINK_PERIOD_1250MS - LTC3220_BLINK_ON_625MS;
+		break;
+	case LTC3220_BLINK_MODE_156MS_1250MS:
+		*delay_on = LTC3220_BLINK_ON_156MS;
+		*delay_off = LTC3220_BLINK_PERIOD_1250MS - LTC3220_BLINK_ON_156MS;
+		break;
+	case LTC3220_BLINK_MODE_625MS_2500MS:
+		*delay_on = LTC3220_BLINK_ON_625MS;
+		*delay_off = LTC3220_BLINK_PERIOD_2500MS - LTC3220_BLINK_ON_625MS;
+		break;
+	case LTC3220_BLINK_MODE_156MS_2500MS:
+		*delay_on = LTC3220_BLINK_ON_156MS;
+		*delay_off = LTC3220_BLINK_PERIOD_2500MS - LTC3220_BLINK_ON_156MS;
+		break;
+	}
+
+	return regmap_update_bits(ltc3220_state->regmap, LTC3220_GRAD_BLINK_REG,
+				  LTC3220_BLINK_MASK, blink_mode);
+}
+
+static void ltc3220_reset_gpio_action(void *data)
+{
+	struct gpio_desc *reset_gpio = data;
+
+	gpiod_set_value_cansleep(reset_gpio, 1);
+}
+
+static int ltc3220_reset(struct ltc3220_state *ltc3220_state, struct i2c_client *client)
+{
+	struct gpio_desc *reset_gpio;
+	int ret;
+	int i;
+
+	reset_gpio = devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(reset_gpio))
+		return dev_err_probe(&client->dev, PTR_ERR(reset_gpio), "Failed on reset GPIO\n");
+
+	if (reset_gpio) {
+		gpiod_set_value_cansleep(reset_gpio, 0);
+
+		return devm_add_action_or_reset(&client->dev, ltc3220_reset_gpio_action,
+						reset_gpio);
+	}
+
+	ret = regmap_write(ltc3220_state->regmap, LTC3220_COMMAND_REG, 0);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < LTC3220_NUM_LEDS; i++) {
+		ret = regmap_write(ltc3220_state->regmap, LTC3220_ULED_REG(i), 0);
+		if (ret < 0)
+			return ret;
+	}
+
+	return regmap_write(ltc3220_state->regmap, LTC3220_GRAD_BLINK_REG, 0);
+}
+
+static int ltc3220_suspend(struct device *dev)
+{
+	struct ltc3220_state *ltc3220_state = i2c_get_clientdata(to_i2c_client(dev));
+
+	return ltc3220_shutdown(ltc3220_state);
+}
+
+static int ltc3220_resume(struct device *dev)
+{
+	struct ltc3220_state *ltc3220_state = i2c_get_clientdata(to_i2c_client(dev));
+
+	return ltc3220_resume_from_shutdown(ltc3220_state);
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(ltc3220_pm_ops, ltc3220_suspend, ltc3220_resume);
+
+static int ltc3220_probe(struct i2c_client *client)
+{
+	struct ltc3220_state *ltc3220_state;
+	bool aggregated_led_found = false;
+	int num_leds = 0;
+	u8 led_index = 0;
+	int ret;
+
+	ltc3220_state = devm_kzalloc(&client->dev, sizeof(*ltc3220_state), GFP_KERNEL);
+	if (!ltc3220_state)
+		return -ENOMEM;
+
+	ltc3220_state->regmap = devm_regmap_init_i2c(client, &ltc3220_regmap_config);
+	if (IS_ERR(ltc3220_state->regmap))
+		return dev_err_probe(&client->dev, PTR_ERR(ltc3220_state->regmap),
+				     "Failed to initialize regmap\n");
+
+	i2c_set_clientdata(client, ltc3220_state);
+
+	ret = ltc3220_reset(ltc3220_state, client);
+	if (ret)
+		return dev_err_probe(&client->dev, ret, "Failed to reset device\n");
+
+	device_for_each_child_node_scoped(&client->dev, child) {
+		struct led_init_data init_data = {};
+		struct ltc3220_uled_cfg *led;
+		u32 source;
+
+		ret = fwnode_property_read_u32(child, "reg", &source);
+		if (ret)
+			return dev_err_probe(&client->dev, ret, "Couldn't read LED address\n");
+
+		if (!source || source > LTC3220_NUM_LEDS)
+			return dev_err_probe(&client->dev, -EINVAL, "LED address out of range\n");
+
+		init_data.fwnode = child;
+		init_data.devicename = "ltc3220";
+
+		if (fwnode_property_present(child, "led-sources")) {
+			if (source != 1)
+				return dev_err_probe(&client->dev, -EINVAL,
+						     "Aggregated LED out of range\n");
+
+			if (aggregated_led_found)
+				return dev_err_probe(&client->dev, -EINVAL,
+						     "One Aggregated LED only\n");
+
+			aggregated_led_found = true;
+			ltc3220_state->is_aggregated = true;
+
+			ret = regmap_update_bits(ltc3220_state->regmap,
+						 LTC3220_COMMAND_REG,
+						 LTC3220_QUICK_WRITE_MASK,
+						 LTC3220_QUICK_WRITE_MASK);
+			if (ret < 0)
+				return dev_err_probe(&client->dev, ret,
+						     "Failed to set quick write mode\n");
+		}
+
+		num_leds++;
+
+		/* LED node reg/index/address goes from 1 to 18 */
+		led_index = source - 1;
+		led = &ltc3220_state->uled_cfg[led_index];
+		led->led_index = led_index;
+		led->reg_value = 0;
+		led->ltc3220_state = ltc3220_state;
+		led->led_cdev.brightness_set_blocking = ltc3220_set_led_data;
+		led->led_cdev.brightness_get = ltc3220_get_led_data;
+		led->led_cdev.max_brightness = 255;
+		led->led_cdev.blink_set = ltc3220_blink_set;
+		led->led_cdev.pattern_set = ltc3220_pattern_set;
+		led->led_cdev.pattern_clear = ltc3220_pattern_clear;
+
+		ret = devm_led_classdev_register_ext(&client->dev, &led->led_cdev, &init_data);
+		if (ret)
+			return dev_err_probe(&client->dev, ret, "Failed to register LED class\n");
+	}
+
+	/*
+	 * Aggregated LED mode uses hardware quick-write to control all 18 LEDs
+	 * simultaneously. This is mutually exclusive with individual LED control.
+	 * See Documentation/devicetree/bindings/leds/adi,ltc3220.yaml for details
+	 * on how to configure aggregated LED mode.
+	 */
+	if (aggregated_led_found && num_leds > 1)
+		return dev_err_probe(&client->dev, -EINVAL,
+				     "Aggregated LED must be the only LED node\n");
+
+	return 0;
+}
+
+static const struct of_device_id ltc3220_of_match[] = {
+	{ .compatible = "adi,ltc3220" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ltc3220_of_match);
+
+static struct i2c_driver ltc3220_led_driver = {
+	.driver = {
+		.name = "ltc3220",
+		.of_match_table = ltc3220_of_match,
+		.pm = pm_sleep_ptr(&ltc3220_pm_ops),
+	},
+	.probe = ltc3220_probe,
+};
+module_i2c_driver(ltc3220_led_driver);
+
+MODULE_AUTHOR("Edelweise Escala <edelweise.escala@analog.com>");
+MODULE_DESCRIPTION("LED driver for LTC3220 controllers");
+MODULE_LICENSE("GPL");

-- 
2.43.0

Re: [PATCH v6 2/2] leds: ltc3220: Add Support for LTC3220 18 channel LED Driver

[Lee Jones]

On Fri, 17 Apr 2026, Edelweise Escala wrote:

> Add driver for the LTC3220 18-channel LED driver
> with I2C interface, individual brightness control, and hardware-assisted
> blink/gradation features.
> 
> Signed-off-by: Edelweise Escala <edelweise.escala@analog.com>
> ---
>  MAINTAINERS                 |   1 +
>  drivers/leds/Kconfig        |  12 ++
>  drivers/leds/Makefile       |   1 +
>  drivers/leds/leds-ltc3220.c | 418 ++++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 432 insertions(+)
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 5c10cc3e3022..7467537938bf 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -14961,6 +14961,7 @@ L:	linux-leds@vger.kernel.org
>  S:	Maintained
>  W:	https://ez.analog.com/linux-software-drivers
>  F:	Documentation/devicetree/bindings/leds/adi,ltc3220.yaml
> +F:	drivers/leds/leds-ltc3220.c
>  
>  LTC4282 HARDWARE MONITOR DRIVER
>  M:	Nuno Sa <nuno.sa@analog.com>
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index 597d7a79c988..f00cdc11c978 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -1001,6 +1001,18 @@ config LEDS_ST1202
>  	  Say Y to enable support for LEDs connected to LED1202
>  	  LED driver chips accessed via the I2C bus.
>  
> +config LEDS_LTC3220
> +	tristate "LED Driver for Analog Devices Inc. LTC3220"
> +	depends on I2C && LEDS_CLASS
> +	help
> +	  Say Y to enable support for the Analog Devices LTC3220
> +	  18-channel LED controller with I2C interface.
> +	  The driver supports individual LED brightness control (64 steps),
> +	  hardware-assisted blinking and gradation effects.
> +
> +	  To compile this driver as a module, choose M here: the module will
> +	  be called leds-ltc3220.
> +
>  config LEDS_TPS6105X
>  	tristate "LED support for TI TPS6105X"
>  	depends on LEDS_CLASS
> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> index 8fdb45d5b439..5301568d9e00 100644
> --- a/drivers/leds/Makefile
> +++ b/drivers/leds/Makefile
> @@ -61,6 +61,7 @@ obj-$(CONFIG_LEDS_LP8788)		+= leds-lp8788.o
>  obj-$(CONFIG_LEDS_LP8860)		+= leds-lp8860.o
>  obj-$(CONFIG_LEDS_LP8864)		+= leds-lp8864.o
>  obj-$(CONFIG_LEDS_LT3593)		+= leds-lt3593.o
> +obj-$(CONFIG_LEDS_LTC3220)		+= leds-ltc3220.o
>  obj-$(CONFIG_LEDS_MAX5970)		+= leds-max5970.o
>  obj-$(CONFIG_LEDS_MAX77650)		+= leds-max77650.o
>  obj-$(CONFIG_LEDS_MAX77705)		+= leds-max77705.o
> diff --git a/drivers/leds/leds-ltc3220.c b/drivers/leds/leds-ltc3220.c
> new file mode 100644
> index 000000000000..5e1f994cc35b
> --- /dev/null
> +++ b/drivers/leds/leds-ltc3220.c
> @@ -0,0 +1,418 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * LTC3220 18-Channel LED Driver
> + *
> + * Copyright 2026 Analog Devices Inc.
> + *
> + * Author: Edelweise Escala <edelweise.escala@analog.com>
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/leds.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +#include <linux/types.h>
> +
> +/* LTC3220 Registers */
> +#define LTC3220_COMMAND_REG				0x00
> +#define   LTC3220_QUICK_WRITE_MASK			BIT(0)
> +#define   LTC3220_SHUTDOWN_MASK				BIT(3)
> +
> +#define LTC3220_ULED_REG(x)				(0x01 + (x))
> +#define   LTC3220_LED_CURRENT_MASK			GENMASK(5, 0)
> +#define   LTC3220_LED_MODE_MASK				GENMASK(7, 6)
> +
> +#define LTC3220_GRAD_BLINK_REG				0x13
> +#define   LTC3220_GRADATION_MASK			GENMASK(2, 0)
> +#define   LTC3220_GRADATION_DIRECTION_MASK		BIT(0)
> +#define   LTC3220_GRADATION_PERIOD_MASK			GENMASK(2, 1)
> +#define   LTC3220_BLINK_MASK				GENMASK(4, 3)
> +
> +#define LTC3220_NUM_LEDS				18
> +
> +#define LTC3220_GRADATION_START_VALUE			128
> +#define LTC3220_GRADATION_RAMP_TIME_240MS		240
> +#define LTC3220_GRADATION_RAMP_TIME_480MS		480
> +
> +#define LTC3220_BLINK_ON_156MS				156
> +#define LTC3220_BLINK_ON_625MS				625
> +#define LTC3220_BLINK_PERIOD_1250MS			1250
> +#define LTC3220_BLINK_PERIOD_2500MS			2500
> +
> +#define LTC3220_BLINK_SHORT_ON_TIME			BIT(0)
> +#define LTC3220_BLINK_LONG_PERIOD			BIT(1)
> +
> +enum ltc3220_blink_mode {
> +	LTC3220_BLINK_MODE_625MS_1250MS,
> +	LTC3220_BLINK_MODE_156MS_1250MS,
> +	LTC3220_BLINK_MODE_625MS_2500MS,
> +	LTC3220_BLINK_MODE_156MS_2500MS
> +};
> +
> +enum ltc3220_gradation_mode {
> +	LTC3220_GRADATION_MODE_DISABLED,
> +	LTC3220_GRADATION_MODE_240MS_RAMP_TIME,
> +	LTC3220_GRADATION_MODE_480MS_RAMP_TIME,
> +	LTC3220_GRADATION_MODE_960MS_RAMP_TIME
> +};
> +
> +static const struct regmap_config ltc3220_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +	.max_register = LTC3220_GRAD_BLINK_REG,
> +};

.cache_type?

> +
> +struct ltc3220_uled_cfg {
> +	struct ltc3220_state *ltc3220_state;

This is not a linked list.  Use container_of() instead.

> +	u8 reg_value;
> +	u8 led_index;
> +};
> +
> +struct ltc3220_state {

Drop the "_state" part.

> +	struct ltc3220_uled_cfg uled_cfg[LTC3220_NUM_LEDS];
> +	struct regmap *regmap;
> +	bool is_aggregated;
> +};
> +
> +static int ltc3220_shutdown(struct ltc3220_state *ltc3220_state)
> +{
> +	return regmap_update_bits(ltc3220_state->regmap, LTC3220_COMMAND_REG,
> +				  LTC3220_SHUTDOWN_MASK, LTC3220_SHUTDOWN_MASK);
> +}
> +
> +static int ltc3220_resume_from_shutdown(struct ltc3220_state *ltc3220_state)
> +{
> +	return regmap_update_bits(ltc3220_state->regmap, LTC3220_COMMAND_REG,
> +				  LTC3220_SHUTDOWN_MASK, 0);
> +}

These do not need to be abstracted out.

> +
> +/*
> + * Set LED brightness and mode.
> + * The brightness value determines both the LED current and operating mode:
> + * 0-63:    Normal mode - LED current from 0-63 (off to full brightness)
> + * 64-127:  Blink mode - LED blinks with current level (brightness - 64)
> + * 128-191: Gradation mode - LED gradually changes brightness (brightness - 128)
> + * 192-255: GPO mode - LED operates as general purpose output (brightness - 192)
> + */
> +static int ltc3220_set_led_data(struct led_classdev *led_cdev,
> +				enum led_brightness brightness)
> +{
> +	struct ltc3220_state *ltc3220_state;
> +	struct ltc3220_uled_cfg *uled_cfg;
> +	int ret;
> +	int i;
> +
> +	uled_cfg = container_of(led_cdev, struct ltc3220_uled_cfg, led_cdev);
> +	ltc3220_state = uled_cfg->ltc3220_state;
> +
> +	ret = regmap_write(ltc3220_state->regmap, LTC3220_ULED_REG(uled_cfg->led_index),
> +			   brightness);
> +	if (ret < 0)

Should we be using 'if (ret)' to check for errors here instead of 'if (ret < 0)'?

> +		return ret;
> +
> +	uled_cfg->reg_value = brightness;
> +
> +	/*
> +	 * When aggregated LED mode is enabled, writing to LED 1 updates all
> +	 * LEDs simultaneously via quick-write mode. Update cached values for
> +	 * all LEDs to reflect the synchronized state.
> +	 * See Documentation/devicetree/bindings/leds/adi,ltc3220.yaml for how
> +	 * to configure aggregated LED mode.
> +	 */
> +	if (ltc3220_state->is_aggregated && uled_cfg->led_index == 0) {
> +		for (i = 0; i < LTC3220_NUM_LEDS; i++)

for (int i = 0; ...

> +			ltc3220_state->uled_cfg[i].reg_value = brightness;
> +	}
> +
> +	return 0;
> +}
> +
> +static enum led_brightness ltc3220_get_led_data(struct led_classdev *led_cdev)
> +{
> +	struct ltc3220_uled_cfg *uled_cfg = container_of(led_cdev,
> +							 struct ltc3220_uled_cfg, led_cdev);
> +
> +	return uled_cfg->reg_value;
> +}
> +
> +/*
> + * LTC3220 pattern support for hardware-assisted breathing/gradation.
> + * The hardware supports 3 gradation ramp time 240ms, 480ms, 960ms)
> + * and can ramp up or down.
> + *
> + * Pattern array interpretation:
> + *   pattern[0].brightness = start brightness (0-63)
> + *   pattern[0].delta_t = ramp time in milliseconds
> + *   pattern[1].brightness = end brightness (0-63)
> + *   pattern[1].delta_t = (optional, can be 0 or same as pattern[0].delta_t)
> + */
> +static int ltc3220_pattern_set(struct led_classdev *led_cdev,
> +			       struct led_pattern *pattern,
> +			       u32 len, int repeat)
> +{
> +	struct ltc3220_uled_cfg *uled_cfg = container_of(led_cdev, struct ltc3220_uled_cfg,
> +							 led_cdev);

This is the 3rd time we do this and every time has been different.

> +	struct ltc3220_state *ltc3220_state = uled_cfg->ltc3220_state;
> +	u8 gradation_period;
> +	u8 start_brightness;
> +	u8 end_brightness;
> +	u8 reg_val;

Something a little more descriptive please.

> +	bool is_increasing;
> +	int ret;
> +
> +	if (len != 2)
> +		return -EINVAL;
> +
> +	start_brightness = pattern[0].brightness & LTC3220_LED_CURRENT_MASK;
> +	end_brightness = pattern[1].brightness & LTC3220_LED_CURRENT_MASK;
> +
> +	is_increasing = end_brightness > start_brightness;
> +
> +	if (pattern[0].delta_t == 0)
> +		gradation_period = LTC3220_GRADATION_MODE_DISABLED;
> +	else if (pattern[0].delta_t <= LTC3220_GRADATION_RAMP_TIME_240MS)
> +		gradation_period = LTC3220_GRADATION_MODE_240MS_RAMP_TIME;
> +	else if (pattern[0].delta_t <= LTC3220_GRADATION_RAMP_TIME_480MS)
> +		gradation_period = LTC3220_GRADATION_MODE_480MS_RAMP_TIME;
> +	else
> +		gradation_period = LTC3220_GRADATION_MODE_960MS_RAMP_TIME;
> +
> +	reg_val = FIELD_PREP(LTC3220_GRADATION_PERIOD_MASK, gradation_period);
> +	reg_val |= FIELD_PREP(LTC3220_GRADATION_DIRECTION_MASK, is_increasing);
> +
> +	ret = regmap_update_bits(ltc3220_state->regmap, LTC3220_GRAD_BLINK_REG,
> +				 LTC3220_GRADATION_MASK, reg_val);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = ltc3220_set_led_data(led_cdev, start_brightness);
> +	if (ret < 0)
> +		return ret;
> +
> +	return ltc3220_set_led_data(led_cdev, LTC3220_GRADATION_START_VALUE + end_brightness);
> +}
> +
> +static int ltc3220_pattern_clear(struct led_classdev *led_cdev)
> +{
> +	struct ltc3220_uled_cfg *uled_cfg = container_of(led_cdev, struct ltc3220_uled_cfg,
> +							 led_cdev);
> +	struct ltc3220_state *ltc3220_state = uled_cfg->ltc3220_state;
> +
> +	return regmap_update_bits(ltc3220_state->regmap, LTC3220_GRAD_BLINK_REG,
> +							  LTC3220_GRADATION_MASK, 0);

Odd tabbing.

> +}
> +
> +/*
> + * LTC3220 has a global blink configuration that affects all LEDs.
> + * This implementation allows per-LED blink requests, but the blink timing
> + * will be shared across all LEDs. The delay values are mapped to the
> + * hardware's discrete blink rates.
> + */
> +static int ltc3220_blink_set(struct led_classdev *led_cdev,
> +			     unsigned long *delay_on,
> +			     unsigned long *delay_off)
> +{
> +	struct ltc3220_uled_cfg *uled_cfg = container_of(led_cdev, struct ltc3220_uled_cfg,
> +							 led_cdev);
> +	struct ltc3220_state *ltc3220_state = uled_cfg->ltc3220_state;
> +	u8 blink_mode = 0;
> +
> +	if (*delay_on <= LTC3220_BLINK_ON_156MS)
> +		blink_mode = LTC3220_BLINK_SHORT_ON_TIME;
> +
> +	if (*delay_on + *delay_off > LTC3220_BLINK_PERIOD_1250MS)
> +		blink_mode |= LTC3220_BLINK_LONG_PERIOD;
> +
> +	switch (blink_mode) {
> +	case LTC3220_BLINK_MODE_625MS_1250MS:
> +		*delay_on = LTC3220_BLINK_ON_625MS;
> +		*delay_off = LTC3220_BLINK_PERIOD_1250MS - LTC3220_BLINK_ON_625MS;
> +		break;
> +	case LTC3220_BLINK_MODE_156MS_1250MS:
> +		*delay_on = LTC3220_BLINK_ON_156MS;
> +		*delay_off = LTC3220_BLINK_PERIOD_1250MS - LTC3220_BLINK_ON_156MS;
> +		break;
> +	case LTC3220_BLINK_MODE_625MS_2500MS:
> +		*delay_on = LTC3220_BLINK_ON_625MS;
> +		*delay_off = LTC3220_BLINK_PERIOD_2500MS - LTC3220_BLINK_ON_625MS;
> +		break;
> +	case LTC3220_BLINK_MODE_156MS_2500MS:
> +		*delay_on = LTC3220_BLINK_ON_156MS;
> +		*delay_off = LTC3220_BLINK_PERIOD_2500MS - LTC3220_BLINK_ON_156MS;
> +		break;
> +	}
> +
> +	return regmap_update_bits(ltc3220_state->regmap, LTC3220_GRAD_BLINK_REG,
> +				  LTC3220_BLINK_MASK, blink_mode);
> +}
> +
> +static void ltc3220_reset_gpio_action(void *data)
> +{
> +	struct gpio_desc *reset_gpio = data;
> +
> +	gpiod_set_value_cansleep(reset_gpio, 1);
> +}
> +
> +static int ltc3220_reset(struct ltc3220_state *ltc3220_state, struct i2c_client *client)
> +{
> +	struct gpio_desc *reset_gpio;
> +	int ret;
> +	int i;
> +
> +	reset_gpio = devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_HIGH);
> +	if (IS_ERR(reset_gpio))
> +		return dev_err_probe(&client->dev, PTR_ERR(reset_gpio), "Failed on reset GPIO\n");
> +
> +	if (reset_gpio) {
> +		gpiod_set_value_cansleep(reset_gpio, 0);
> +
> +		return devm_add_action_or_reset(&client->dev, ltc3220_reset_gpio_action,
> +						reset_gpio);
> +	}
> +
> +	ret = regmap_write(ltc3220_state->regmap, LTC3220_COMMAND_REG, 0);
> +	if (ret < 0)
> +		return ret;
> +
> +	for (i = 0; i < LTC3220_NUM_LEDS; i++) {

As above.

> +		ret = regmap_write(ltc3220_state->regmap, LTC3220_ULED_REG(i), 0);
> +		if (ret < 0)
> +			return ret;
> +	}
> +
> +	return regmap_write(ltc3220_state->regmap, LTC3220_GRAD_BLINK_REG, 0);
> +}
> +
> +static int ltc3220_suspend(struct device *dev)
> +{
> +	struct ltc3220_state *ltc3220_state = i2c_get_clientdata(to_i2c_client(dev));
> +
> +	return ltc3220_shutdown(ltc3220_state);
> +}
> +
> +static int ltc3220_resume(struct device *dev)
> +{
> +	struct ltc3220_state *ltc3220_state = i2c_get_clientdata(to_i2c_client(dev));
> +
> +	return ltc3220_resume_from_shutdown(ltc3220_state);
> +}
> +
> +static DEFINE_SIMPLE_DEV_PM_OPS(ltc3220_pm_ops, ltc3220_suspend, ltc3220_resume);
> +
> +static int ltc3220_probe(struct i2c_client *client)
> +{
> +	struct ltc3220_state *ltc3220_state;
> +	bool aggregated_led_found = false;
> +	int num_leds = 0;
> +	u8 led_index = 0;
> +	int ret;
> +
> +	ltc3220_state = devm_kzalloc(&client->dev, sizeof(*ltc3220_state), GFP_KERNEL);
> +	if (!ltc3220_state)
> +		return -ENOMEM;
> +
> +	ltc3220_state->regmap = devm_regmap_init_i2c(client, &ltc3220_regmap_config);
> +	if (IS_ERR(ltc3220_state->regmap))
> +		return dev_err_probe(&client->dev, PTR_ERR(ltc3220_state->regmap),
> +				     "Failed to initialize regmap\n");
> +
> +	i2c_set_clientdata(client, ltc3220_state);
> +
> +	ret = ltc3220_reset(ltc3220_state, client);
> +	if (ret)
> +		return dev_err_probe(&client->dev, ret, "Failed to reset device\n");
> +
> +	device_for_each_child_node_scoped(&client->dev, child) {
> +		struct led_init_data init_data = {};
> +		struct ltc3220_uled_cfg *led;
> +		u32 source;
> +
> +		ret = fwnode_property_read_u32(child, "reg", &source);
> +		if (ret)
> +			return dev_err_probe(&client->dev, ret, "Couldn't read LED address\n");
> +
> +		if (!source || source > LTC3220_NUM_LEDS)
> +			return dev_err_probe(&client->dev, -EINVAL, "LED address out of range\n");
> +
> +		init_data.fwnode = child;
> +		init_data.devicename = "ltc3220";
> +
> +		if (fwnode_property_present(child, "led-sources")) {
> +			if (source != 1)
> +				return dev_err_probe(&client->dev, -EINVAL,
> +						     "Aggregated LED out of range\n");
> +
> +			if (aggregated_led_found)
> +				return dev_err_probe(&client->dev, -EINVAL,
> +						     "One Aggregated LED only\n");
> +
> +			aggregated_led_found = true;
> +			ltc3220_state->is_aggregated = true;
> +
> +			ret = regmap_update_bits(ltc3220_state->regmap,
> +						 LTC3220_COMMAND_REG,
> +						 LTC3220_QUICK_WRITE_MASK,
> +						 LTC3220_QUICK_WRITE_MASK);
> +			if (ret < 0)
> +				return dev_err_probe(&client->dev, ret,
> +						     "Failed to set quick write mode\n");
> +		}
> +
> +		num_leds++;
> +
> +		/* LED node reg/index/address goes from 1 to 18 */
> +		led_index = source - 1;
> +		led = &ltc3220_state->uled_cfg[led_index];
> +		led->led_index = led_index;
> +		led->reg_value = 0;
> +		led->ltc3220_state = ltc3220_state;
> +		led->led_cdev.brightness_set_blocking = ltc3220_set_led_data;
> +		led->led_cdev.brightness_get = ltc3220_get_led_data;
> +		led->led_cdev.max_brightness = 255;
> +		led->led_cdev.blink_set = ltc3220_blink_set;
> +		led->led_cdev.pattern_set = ltc3220_pattern_set;
> +		led->led_cdev.pattern_clear = ltc3220_pattern_clear;
> +
> +		ret = devm_led_classdev_register_ext(&client->dev, &led->led_cdev, &init_data);
> +		if (ret)
> +			return dev_err_probe(&client->dev, ret, "Failed to register LED class\n");
> +	}
> +
> +	/*
> +	 * Aggregated LED mode uses hardware quick-write to control all 18 LEDs
> +	 * simultaneously. This is mutually exclusive with individual LED control.
> +	 * See Documentation/devicetree/bindings/leds/adi,ltc3220.yaml for details
> +	 * on how to configure aggregated LED mode.
> +	 */
> +	if (aggregated_led_found && num_leds > 1)
> +		return dev_err_probe(&client->dev, -EINVAL,
> +				     "Aggregated LED must be the only LED node\n");
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id ltc3220_of_match[] = {
> +	{ .compatible = "adi,ltc3220" },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, ltc3220_of_match);
> +
> +static struct i2c_driver ltc3220_led_driver = {
> +	.driver = {
> +		.name = "ltc3220",
> +		.of_match_table = ltc3220_of_match,
> +		.pm = pm_sleep_ptr(&ltc3220_pm_ops),
> +	},
> +	.probe = ltc3220_probe,
> +};
> +module_i2c_driver(ltc3220_led_driver);
> +
> +MODULE_AUTHOR("Edelweise Escala <edelweise.escala@analog.com>");
> +MODULE_DESCRIPTION("LED driver for LTC3220 controllers");
> +MODULE_LICENSE("GPL");
> 
> -- 
> 2.43.0
> 

-- 
Lee Jones