[PATCH v6 0/2] leds: Add IS32FL3207 controller support

[PATCH v6 0/2] leds: Add IS32FL3207 controller support

[Ahmad Byagowi]

Add a binding and LED-class driver for the Lumissil IS32FL3207
18-channel constant-current LED controller. The driver supports individual
and multicolor LEDs, per-output current limits, an optional supply, and an
optional SDB GPIO.

This is the LED prerequisite split out of the Time Card v5 series following
the netdev maintainer's guidance. The dependent ptp_ocp board profiles will
be resent to net-next after the LED and I2C prerequisites land.

Changes since v5:
  - Send the binding and driver as a standalone LED series.
  - Raise the minimum led-max-microamp value to 149 uA, the lowest nonzero
    setting representable at the maximum permitted full-scale current.
  - Rebase onto the LED for-leds-next branch.

Krzysztof's Reviewed-by from v3 is not carried because the binding changed
materially after that review. It now supports groups beginning at outputs
16 and 17, documents the RISET/current-limit relationship, and enforces the
controller's minimum representable current.

Validation:
  - dt-doc-validate
  - dt-check-style --mode=strict
  - targeted dt_binding_check
  - x86-64 and arm64 defconfig/allmodconfig W=1 object builds

v5: https://lore.kernel.org/r/cover.1786746757.git.ahmadexp@gmail.com/

Ahmad Byagowi (2):
  dt-bindings: leds: Add IS32FL3207 controller
  leds: is32fl3207: Add controller driver

 .../bindings/leds/issi,is32fl3207.yaml        | 285 +++++++
 MAINTAINERS                                   |   7 +
 drivers/leds/rgb/Kconfig                      |  11 +
 drivers/leds/rgb/Makefile                     |   1 +
 drivers/leds/rgb/leds-is32fl3207.c            | 736 ++++++++++++++++++
 5 files changed, 1040 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/issi,is32fl3207.yaml
 create mode 100644 drivers/leds/rgb/leds-is32fl3207.c


base-commit: f8cca63a0a4f3475199d9ab7f86782bdfeb0744d
-- 
2.50.1 (Apple Git-155)

[PATCH v6 1/2] dt-bindings: leds: Add IS32FL3207 controller

[Ahmad Byagowi]

The IS32FL3207 is an 18-channel constant-current LED controller with
per-output PWM and current scaling.

Describe I2C addressing, power and shutdown controls, RISET, and
individual or multicolor output groupings. Require board current limits
for each output and document their relationship to the RISET-derived full
scale.

Allow dash-suffixed multicolor group names when a group begins at channel
16 or 17, which cannot be represented by the common schema unit-address
form.

Signed-off-by: Ahmad Byagowi <ahmadexp@gmail.com>
---
 .../bindings/leds/issi,is32fl3207.yaml        | 285 ++++++++++++++++++
 MAINTAINERS                                   |   6 +
 2 files changed, 291 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/issi,is32fl3207.yaml

diff --git a/Documentation/devicetree/bindings/leds/issi,is32fl3207.yaml b/Documentation/devicetree/bindings/leds/issi,is32fl3207.yaml
new file mode 100644
index 0000000000000..32eaf14ca7cf3
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/issi,is32fl3207.yaml
@@ -0,0 +1,285 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/issi,is32fl3207.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Lumissil IS32FL3207 18-channel LED controller
+
+maintainers:
+  - Ahmad Byagowi <ahmadexp@gmail.com>
+
+description: |
+  The IS32FL3207 is an I2C LED controller with 18 individually controlled
+  constant-current outputs. Each output has 8-bit current scaling. PWM
+  brightness control uses the controller's default 8-bit, 62 kHz mode.
+  Outputs may be exposed as individual LEDs or grouped as multicolor LEDs.
+
+  The data sheet is available at:
+    https://www.lumissil.com/assets/pdf/core/IS32FL3207_DS.pdf
+
+properties:
+  compatible:
+    const: issi,is32fl3207
+
+  reg:
+    enum: [0x34, 0x35, 0x36, 0x37]
+
+  vcc-supply:
+    description: Regulator providing power to the VCC pin.
+
+  enable-gpios:
+    maxItems: 1
+    description: GPIO connected to SDB, asserted to enable the controller.
+
+  issi,riset-ohms:
+    minimum: 2000
+    maximum: 76500000
+    description: |
+      Resistance in ohms of the external RISET resistor. The resistor sets the
+      full-scale output current according to IOUT(MAX) = 76.5 / RISET amperes.
+      Each LED's led-max-microamp value selects a board-safe peak current no
+      greater than this full scale, using the per-output scaling register.
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+patternProperties:
+  "^led@[0-9a-f]+$":
+    type: object
+    $ref: common.yaml#
+    unevaluatedProperties: false
+
+    properties:
+      reg:
+        minimum: 0
+        maximum: 17
+        description: |
+          Zero-based LED output number. Values 0 through 17 correspond to
+          OUT1 through OUT18.
+
+      led-max-microamp:
+        minimum: 149
+        maximum: 38250
+        description: |
+          Board-safe peak current for this output. The value must not exceed
+          the full-scale current derived from issi,riset-ohms. The minimum is
+          the smallest nonzero current representable at the maximum permitted
+          full-scale current.
+
+      color:
+        oneOf:
+          - minimum: 0
+            maximum: 7
+          - minimum: 10
+            maximum: 14
+
+      max-brightness:
+        minimum: 1
+        maximum: 255
+
+      default-state:
+        description:
+          The driver performs a software reset and clears the PWM state during
+          initialization, so an existing state cannot be preserved.
+        enum: ["on", "off"]
+
+      default-brightness:
+        maximum: 255
+        description: |
+          Brightness used when default-state is "on". This value must not
+          exceed max-brightness when max-brightness is specified.
+
+    anyOf:
+      - required:
+          - function
+      - required:
+          - color
+
+    required:
+      - reg
+      - led-max-microamp
+
+  "^multi-led(@[0-9a-f]|-[0-9]+)?$":
+    type: object
+    $ref: leds-class-multicolor.yaml#
+    unevaluatedProperties: false
+
+    properties:
+      reg:
+        minimum: 0
+        maximum: 15
+        description: |
+          Optional zero-based lowest-numbered output used by a group named
+          multi-led@N. Values 0 through 15 correspond to OUT1 through OUT16.
+          For a multi-led-N group without reg, the driver derives the lowest
+          output from its component nodes. This form permits groups beginning
+          at channels 16 or 17 while following the common multicolor node-name
+          schema.
+
+      "#address-cells":
+        const: 1
+
+      "#size-cells":
+        const: 0
+
+      max-brightness:
+        minimum: 1
+        maximum: 255
+
+      default-state:
+        description:
+          The driver performs a software reset and clears the PWM state during
+          initialization, so an existing state cannot be preserved.
+        enum: ["on", "off"]
+
+      default-brightness:
+        maximum: 255
+        description: |
+          Brightness used when default-state is "on". This value must not
+          exceed max-brightness when max-brightness is specified.
+
+    patternProperties:
+      "^led@[0-9a-f]+$":
+        type: object
+        $ref: common.yaml#
+        unevaluatedProperties: false
+
+        properties:
+          reg:
+            minimum: 0
+            maximum: 17
+            description: |
+              Zero-based LED output number. Values 0 through 17 correspond to
+              OUT1 through OUT18.
+
+          led-max-microamp:
+            minimum: 149
+            maximum: 38250
+            description: |
+              Board-safe peak current for this output. The value must not
+              exceed the full-scale current derived from issi,riset-ohms. The
+              minimum is the smallest nonzero current representable at the
+              maximum permitted full-scale current.
+
+          color:
+            oneOf:
+              - minimum: 0
+                maximum: 7
+              - minimum: 10
+                maximum: 14
+
+          max-brightness: false
+
+          default-state: false
+
+          default-brightness: false
+
+          retain-state-shutdown: false
+
+        required:
+          - reg
+          - color
+          - led-max-microamp
+
+    anyOf:
+      - required: [led@0]
+      - required: [led@1]
+      - required: [led@2]
+      - required: [led@3]
+      - required: [led@4]
+      - required: [led@5]
+      - required: [led@6]
+      - required: [led@7]
+      - required: [led@8]
+      - required: [led@9]
+      - required: [led@a]
+      - required: [led@b]
+      - required: [led@c]
+      - required: [led@d]
+      - required: [led@e]
+      - required: [led@f]
+      - required: [led@10]
+      - required: [led@11]
+
+    required:
+      - "#address-cells"
+      - "#size-cells"
+
+required:
+  - compatible
+  - reg
+  - issi,riset-ohms
+  - "#address-cells"
+  - "#size-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/leds/common.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        led-controller@34 {
+            compatible = "issi,is32fl3207";
+            reg = <0x34>;
+            #address-cells = <1>;
+            enable-gpios = <&gpio0 4 GPIO_ACTIVE_HIGH>;
+            #size-cells = <0>;
+            vcc-supply = <&led_3v3>;
+            issi,riset-ohms = <4700>;
+
+            multi-led@0 {
+                reg = <0>;
+                #address-cells = <1>;
+                color = <LED_COLOR_ID_RGB>;
+                function = LED_FUNCTION_STATUS;
+                #size-cells = <0>;
+
+                led@0 {
+                    reg = <0>;
+                    color = <LED_COLOR_ID_RED>;
+                    led-max-microamp = <8100>;
+                };
+
+                led@1 {
+                    reg = <1>;
+                    color = <LED_COLOR_ID_GREEN>;
+                    led-max-microamp = <8100>;
+                };
+
+                led@2 {
+                    reg = <2>;
+                    color = <LED_COLOR_ID_BLUE>;
+                    led-max-microamp = <8100>;
+                };
+            };
+
+            multi-led-1 {
+                #address-cells = <1>;
+                color = <LED_COLOR_ID_MULTI>;
+                function = LED_FUNCTION_INDICATOR;
+                #size-cells = <0>;
+
+                led@10 {
+                    reg = <16>;
+                    color = <LED_COLOR_ID_AMBER>;
+                    led-max-microamp = <8100>;
+                };
+
+                led@11 {
+                    reg = <17>;
+                    color = <LED_COLOR_ID_WHITE>;
+                    led-max-microamp = <8100>;
+                };
+            };
+        };
+    };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index 747ef98f21e85..dbb2fc536c065 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13817,6 +13817,12 @@ S:	Maintained
 F:	Documentation/filesystems/isofs.rst
 F:	fs/isofs/
 
+ISSI IS32FL3207 LED DRIVER
+M:	Ahmad Byagowi <ahmadexp@gmail.com>
+L:	linux-leds@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/leds/issi,is32fl3207.yaml
+
 IT87 HARDWARE MONITORING DRIVER
 M:	Jean Delvare <jdelvare@suse.com>
 L:	linux-hwmon@vger.kernel.org
-- 
2.50.1 (Apple Git-155)

[PATCH v6 2/2] leds: is32fl3207: Add controller driver

[Ahmad Byagowi]

Add an I2C driver for the Lumissil IS32FL3207 18-channel LED controller.

Expose individual and multicolor LEDs through the LED class. Use the
default 8-bit, 62 kHz PWM mode, derive output current from RISET, and
enforce each output current limit with the scaling registers. Serialize
multicolor calculation, scaling, PWM, and controller-wide update
operations.

Clear retained scaling while SDB holds the outputs disabled. Release SDB
and briefly enable normal operation to issue the required software reset,
then keep the controller in software shutdown while registering every LED.
Enable outputs only after all limits and initial brightness values are
programmed.

Handle an optional supply and enable GPIO. Serialize shutdown against
pending brightness updates and honor retained shutdown state.

Signed-off-by: Ahmad Byagowi <ahmadexp@gmail.com>
---
 MAINTAINERS                        |   1 +
 drivers/leds/rgb/Kconfig           |  11 +
 drivers/leds/rgb/Makefile          |   1 +
 drivers/leds/rgb/leds-is32fl3207.c | 736 +++++++++++++++++++++++++++++
 4 files changed, 749 insertions(+)
 create mode 100644 drivers/leds/rgb/leds-is32fl3207.c

diff --git a/MAINTAINERS b/MAINTAINERS
index dbb2fc536c065..79bb970b025db 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13822,6 +13822,7 @@ M:	Ahmad Byagowi <ahmadexp@gmail.com>
 L:	linux-leds@vger.kernel.org
 S:	Maintained
 F:	Documentation/devicetree/bindings/leds/issi,is32fl3207.yaml
+F:	drivers/leds/rgb/leds-is32fl3207.c
 
 IT87 HARDWARE MONITORING DRIVER
 M:	Jean Delvare <jdelvare@suse.com>
diff --git a/drivers/leds/rgb/Kconfig b/drivers/leds/rgb/Kconfig
index 6e9ab5f60714b..c896be1318dcc 100644
--- a/drivers/leds/rgb/Kconfig
+++ b/drivers/leds/rgb/Kconfig
@@ -14,6 +14,17 @@ config LEDS_GROUP_MULTICOLOR
 	  To compile this driver as a module, choose M here: the module
 	  will be called leds-group-multicolor.
 
+config LEDS_IS32FL3207
+	tristate "LED support for ISSI IS32FL3207"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  Say Y here to include support for the Lumissil IS32FL3207
+	  18-channel I2C LED controller.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called leds-is32fl3207.
+
 config LEDS_KTD202X
 	tristate "LED support for KTD202x Chips"
 	depends on I2C
diff --git a/drivers/leds/rgb/Makefile b/drivers/leds/rgb/Makefile
index cc0f2df662869..228923e8bb119 100644
--- a/drivers/leds/rgb/Makefile
+++ b/drivers/leds/rgb/Makefile
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 
 obj-$(CONFIG_LEDS_GROUP_MULTICOLOR)	+= leds-group-multicolor.o
+obj-$(CONFIG_LEDS_IS32FL3207)		+= leds-is32fl3207.o
 obj-$(CONFIG_LEDS_KTD202X)		+= leds-ktd202x.o
 obj-$(CONFIG_LEDS_LP5812)		+= leds-lp5812.o
 obj-$(CONFIG_LEDS_LP5860_CORE)		+= leds-lp5860-core.o
diff --git a/drivers/leds/rgb/leds-is32fl3207.c b/drivers/leds/rgb/leds-is32fl3207.c
new file mode 100644
index 0000000000000..6a46f97ba50a5
--- /dev/null
+++ b/drivers/leds/rgb/leds-is32fl3207.c
@@ -0,0 +1,736 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ISSI IS32FL3207 LED controller driver
+ *
+ * Copyright 2026 Ahmad Byagowi
+ */
+
+#include <linux/bitmap.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/led-class-multicolor.h>
+#include <linux/math64.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/string.h>
+
+#include <dt-bindings/leds/common.h>
+
+#define IS32FL3207_NUM_CHANNELS		18
+#define IS32FL3207_MAX_BRIGHTNESS	255
+
+#define IS32FL3207_REG_CONTROL		0x00
+#define IS32FL3207_REG_PWM_LOW(channel)	(0x01 + 2 * (channel))
+#define IS32FL3207_REG_PWM_UPDATE	0x49
+#define IS32FL3207_REG_SCALING(channel)	(0x4a + (channel))
+#define IS32FL3207_REG_GLOBAL_CURRENT	0x6e
+#define IS32FL3207_REG_RESET		0x7f
+
+#define IS32FL3207_CONTROL_ENABLE	BIT(0)
+#define IS32FL3207_GLOBAL_CURRENT_MAX	0xff
+
+/* IOUT(MAX) in microamperes = 76,500,000 / RISET in ohms. */
+#define IS32FL3207_CURRENT_NUMERATOR	76500000ULL
+
+struct is32fl3207;
+
+struct is32fl3207_led {
+	struct is32fl3207 *chip;
+	struct led_classdev *led_cdev;
+	union {
+		struct led_classdev cdev;
+		struct led_classdev_mc mcdev;
+	};
+	unsigned int channel;
+};
+
+struct is32fl3207 {
+	struct device *dev;
+	struct regmap *regmap;
+	struct gpio_desc *enable_gpio;
+	struct mutex lock; /* Serializes controller register updates. */
+	unsigned long channels[BITS_TO_LONGS(IS32FL3207_NUM_CHANNELS)];
+	u32 output_max_microamp;
+	unsigned int num_leds;
+	bool shutting_down;
+	struct is32fl3207_led leds[] __counted_by(num_leds);
+};
+
+static int is32fl3207_parse_led_properties(struct is32fl3207 *chip,
+					   struct fwnode_handle *fwnode,
+					   unsigned int *max_brightness,
+					   unsigned int *brightness)
+{
+	enum led_default_state default_state;
+	u32 value;
+	int ret;
+
+	*max_brightness = IS32FL3207_MAX_BRIGHTNESS;
+	if (fwnode_property_present(fwnode, "max-brightness")) {
+		ret = fwnode_property_read_u32(fwnode, "max-brightness",
+					       &value);
+		if (ret)
+			return dev_err_probe(chip->dev, ret,
+					     "failed to read maximum brightness for %pfw\n",
+					     fwnode);
+		if (!value || value > IS32FL3207_MAX_BRIGHTNESS)
+			return dev_err_probe(chip->dev, -EINVAL,
+					     "invalid maximum brightness %u for %pfw\n",
+					     value, fwnode);
+
+		*max_brightness = value;
+	}
+
+	value = *max_brightness;
+	if (fwnode_property_present(fwnode, "default-brightness")) {
+		ret = fwnode_property_read_u32(fwnode, "default-brightness",
+					       &value);
+		if (ret)
+			return dev_err_probe(chip->dev, ret,
+					     "failed to read default brightness for %pfw\n",
+					     fwnode);
+		if (value > *max_brightness)
+			return dev_err_probe(chip->dev, -EINVAL,
+					     "invalid default brightness %u for %pfw\n",
+					     value, fwnode);
+	}
+
+	default_state = led_init_default_state_get(fwnode);
+	if (default_state == LEDS_DEFSTATE_KEEP)
+		return dev_err_probe(chip->dev, -EINVAL,
+				     "default state keep is not supported for %pfw\n",
+				     fwnode);
+
+	*brightness = default_state == LEDS_DEFSTATE_ON ? value : LED_OFF;
+	return 0;
+}
+
+static int is32fl3207_validate_component(struct is32fl3207 *chip,
+					 struct fwnode_handle *fwnode)
+{
+	static const char * const unsupported[] = {
+		"default-brightness",
+		"default-state",
+		"max-brightness",
+		"retain-state-shutdown",
+	};
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(unsupported); i++)
+		if (fwnode_property_present(fwnode, unsupported[i]))
+			return dev_err_probe(chip->dev, -EINVAL,
+					     "%s is not supported for component %pfw\n",
+					     unsupported[i], fwnode);
+
+	return 0;
+}
+
+static int is32fl3207_write_channels_locked(struct is32fl3207 *chip,
+					    const struct mc_subled *subleds,
+					    unsigned int num_channels)
+{
+	unsigned int i;
+	int ret;
+
+	for (i = 0; i < num_channels; i++) {
+		ret = regmap_write(chip->regmap,
+				   IS32FL3207_REG_PWM_LOW(subleds[i].channel),
+				   subleds[i].brightness);
+		if (ret)
+			return ret;
+	}
+
+	return regmap_write(chip->regmap, IS32FL3207_REG_PWM_UPDATE, 0);
+}
+
+static int is32fl3207_brightness_set(struct led_classdev *cdev,
+				     enum led_brightness brightness)
+{
+	struct is32fl3207_led *led = container_of(cdev, struct is32fl3207_led,
+						     cdev);
+	struct mc_subled subled = {
+		.brightness = brightness,
+		.channel = led->channel,
+	};
+
+	guard(mutex)(&led->chip->lock);
+	if (led->chip->shutting_down)
+		return 0;
+
+	return is32fl3207_write_channels_locked(led->chip, &subled, 1);
+}
+
+static int is32fl3207_mc_brightness_set(struct led_classdev *cdev,
+					enum led_brightness brightness)
+{
+	struct led_classdev_mc *mcdev = lcdev_to_mccdev(cdev);
+	struct is32fl3207_led *led = container_of(mcdev, struct is32fl3207_led,
+						     mcdev);
+
+	guard(mutex)(&led->chip->lock);
+	if (led->chip->shutting_down)
+		return 0;
+
+	led_mc_calc_color_components(mcdev, brightness);
+
+	return is32fl3207_write_channels_locked(led->chip, mcdev->subled_info,
+						   mcdev->num_colors);
+}
+
+static int is32fl3207_turn_off_locked(struct is32fl3207 *chip,
+				      struct is32fl3207_led *led)
+{
+	struct led_classdev *cdev = led->led_cdev;
+	struct mc_subled subled = {
+		.brightness = LED_OFF,
+		.channel = led->channel,
+	};
+
+	if (cdev->flags & LED_MULTI_COLOR) {
+		struct led_classdev_mc *mcdev = lcdev_to_mccdev(cdev);
+
+		led_mc_calc_color_components(mcdev, LED_OFF);
+		return is32fl3207_write_channels_locked(chip,
+							   mcdev->subled_info,
+							   mcdev->num_colors);
+	}
+
+	return is32fl3207_write_channels_locked(chip, &subled, 1);
+}
+
+static int is32fl3207_configure_channel(struct is32fl3207 *chip,
+					struct fwnode_handle *fwnode,
+					unsigned int *channel)
+{
+	u64 scaling;
+	u32 max_microamp;
+	u32 reg;
+	int ret;
+
+	ret = fwnode_property_read_u32(fwnode, "reg", &reg);
+	if (ret)
+		return dev_err_probe(chip->dev, ret,
+				     "failed to read channel for %pfw\n",
+				     fwnode);
+
+	if (reg >= IS32FL3207_NUM_CHANNELS)
+		return dev_err_probe(chip->dev, -EINVAL,
+				     "channel %u is out of range\n", reg);
+
+	if (test_bit(reg, chip->channels))
+		return dev_err_probe(chip->dev, -EINVAL,
+				     "channel %u is used more than once\n",
+				     reg);
+
+	ret = fwnode_property_read_u32(fwnode, "led-max-microamp",
+				       &max_microamp);
+	if (ret)
+		return dev_err_probe(chip->dev, ret,
+				     "failed to read current limit for channel %u\n",
+				     reg);
+
+	if (!max_microamp || max_microamp > chip->output_max_microamp)
+		return dev_err_probe(chip->dev, -EINVAL,
+				     "invalid current limit %u uA for channel %u\n",
+				     max_microamp, reg);
+
+	/* GCC is fixed at 0xff, so use each output's scaling register. */
+	scaling = div_u64((u64)max_microamp * 256 * 256,
+			  (u64)chip->output_max_microamp *
+			  IS32FL3207_GLOBAL_CURRENT_MAX);
+	if (!scaling)
+		return dev_err_probe(chip->dev, -EINVAL,
+				     "current limit %u uA is below channel %u resolution\n",
+				     max_microamp, reg);
+
+	scaling = min_t(u64, scaling, 0xff);
+
+	guard(mutex)(&chip->lock);
+	ret = regmap_write(chip->regmap, IS32FL3207_REG_SCALING(reg),
+			   (unsigned int)scaling);
+	if (ret)
+		return ret;
+
+	set_bit(reg, chip->channels);
+	*channel = reg;
+
+	return 0;
+}
+
+static int is32fl3207_register_single(struct is32fl3207 *chip,
+				      struct fwnode_handle *fwnode,
+				      struct is32fl3207_led *led)
+{
+	struct led_init_data init_data = {
+		.devicename = dev_name(chip->dev),
+		.devname_mandatory = true,
+		.fwnode = fwnode,
+	};
+	unsigned int max_brightness;
+	unsigned int brightness;
+	u32 color;
+	int ret;
+
+	if (!fwnode_property_present(fwnode, "function") &&
+	    !fwnode_property_present(fwnode, "color"))
+		return dev_err_probe(chip->dev, -EINVAL,
+				     "single LED %pfw requires function or color\n",
+				     fwnode);
+
+	ret = is32fl3207_parse_led_properties(chip, fwnode,
+					      &max_brightness, &brightness);
+	if (ret)
+		return ret;
+
+	if (fwnode_property_present(fwnode, "color")) {
+		ret = fwnode_property_read_u32(fwnode, "color", &color);
+		if (ret)
+			return dev_err_probe(chip->dev, ret,
+					     "failed to read color for %pfw\n",
+					     fwnode);
+		if (color >= LED_COLOR_ID_MAX || color == LED_COLOR_ID_MULTI ||
+		    color == LED_COLOR_ID_RGB)
+			return dev_err_probe(chip->dev, -EINVAL,
+					     "invalid single LED color %u\n",
+					     color);
+	}
+
+	ret = is32fl3207_configure_channel(chip, fwnode, &led->channel);
+	if (ret)
+		return ret;
+	led->chip = chip;
+	led->led_cdev = &led->cdev;
+	led->cdev.brightness = brightness;
+	led->cdev.max_brightness = max_brightness;
+	led->cdev.brightness_set_blocking = is32fl3207_brightness_set;
+
+	ret = is32fl3207_brightness_set(&led->cdev, brightness);
+	if (ret)
+		return ret;
+
+	return devm_led_classdev_register_ext(chip->dev, &led->cdev,
+					      &init_data);
+}
+
+static int is32fl3207_register_multicolor(struct is32fl3207 *chip,
+					  struct fwnode_handle *fwnode,
+					  struct is32fl3207_led *led)
+{
+	struct led_init_data init_data = {
+		.devicename = dev_name(chip->dev),
+		.devname_mandatory = true,
+		.fwnode = fwnode,
+	};
+	struct mc_subled *subleds;
+	DECLARE_BITMAP(color_map, LED_COLOR_ID_MAX);
+	unsigned int max_brightness;
+	unsigned int brightness;
+	unsigned int count;
+	unsigned int i = 0;
+	bool has_group_reg;
+	u32 group_color;
+	u32 group_reg;
+	unsigned int first_channel = IS32FL3207_NUM_CHANNELS;
+	int ret;
+
+	ret = is32fl3207_parse_led_properties(chip, fwnode,
+					      &max_brightness, &brightness);
+	if (ret)
+		return ret;
+
+	ret = fwnode_property_read_u32(fwnode, "color", &group_color);
+	if (ret)
+		return dev_err_probe(chip->dev, ret,
+				     "failed to read color for %pfw\n", fwnode);
+
+	if (group_color != LED_COLOR_ID_RGB &&
+	    group_color != LED_COLOR_ID_MULTI)
+		return dev_err_probe(chip->dev, -EINVAL,
+				     "invalid multicolor LED color %u\n",
+				     group_color);
+
+	has_group_reg = fwnode_property_present(fwnode, "reg");
+	if (has_group_reg) {
+		ret = fwnode_property_read_u32(fwnode, "reg", &group_reg);
+		if (ret)
+			return dev_err_probe(chip->dev, ret,
+					     "failed to read group index for %pfw\n",
+					     fwnode);
+	}
+
+	count = fwnode_get_child_node_count(fwnode);
+	if (!count || count > LED_COLOR_ID_MAX)
+		return dev_err_probe(chip->dev, -EINVAL,
+				     "invalid component count %u for %pfw\n",
+				     count, fwnode);
+
+	subleds = devm_kcalloc(chip->dev, count, sizeof(*subleds), GFP_KERNEL);
+	if (!subleds)
+		return -ENOMEM;
+	bitmap_zero(color_map, LED_COLOR_ID_MAX);
+
+	fwnode_for_each_child_node_scoped(fwnode, child) {
+		u32 color;
+
+		ret = is32fl3207_validate_component(chip, child);
+		if (ret)
+			return ret;
+
+		ret = fwnode_property_read_u32(child, "color", &color);
+		if (ret)
+			return dev_err_probe(chip->dev, ret,
+					     "failed to read color for %pfw\n",
+					     child);
+
+		if (color >= LED_COLOR_ID_MAX || color == LED_COLOR_ID_MULTI ||
+		    color == LED_COLOR_ID_RGB)
+			return dev_err_probe(chip->dev, -EINVAL,
+					     "invalid component color %u\n",
+					     color);
+		if (test_and_set_bit(color, color_map))
+			return dev_err_probe(chip->dev, -EINVAL,
+					     "component color %u is used more than once\n",
+					     color);
+
+		ret = is32fl3207_configure_channel(chip, child,
+						   &subleds[i].channel);
+		if (ret)
+			return ret;
+
+		subleds[i].color_index = color;
+		subleds[i].intensity = max_brightness;
+		subleds[i].max_intensity = 0;
+		first_channel = min(first_channel, subleds[i].channel);
+		i++;
+	}
+
+	if (has_group_reg && group_reg != first_channel)
+		return dev_err_probe(chip->dev, -EINVAL,
+				     "group index %u does not match first channel %u\n",
+				     group_reg, first_channel);
+
+	led->chip = chip;
+	led->led_cdev = &led->mcdev.led_cdev;
+	led->mcdev.num_colors = count;
+	led->mcdev.subled_info = subleds;
+	led->mcdev.led_cdev.brightness = brightness;
+	led->mcdev.led_cdev.max_brightness = max_brightness;
+	led->mcdev.led_cdev.brightness_set_blocking =
+		is32fl3207_mc_brightness_set;
+
+	ret = is32fl3207_mc_brightness_set(&led->mcdev.led_cdev,
+					   brightness);
+	if (ret)
+		return ret;
+
+	return devm_led_classdev_multicolor_register_ext(chip->dev, &led->mcdev,
+						     &init_data);
+}
+
+static int is32fl3207_register_led(struct is32fl3207 *chip,
+				   struct fwnode_handle *fwnode,
+				   struct is32fl3207_led *led)
+{
+	unsigned int count = fwnode_get_child_node_count(fwnode);
+	bool has_color = fwnode_property_present(fwnode, "color");
+	u32 color = LED_COLOR_ID_MAX;
+	int ret;
+
+	if (has_color) {
+		ret = fwnode_property_read_u32(fwnode, "color", &color);
+		if (ret)
+			return dev_err_probe(chip->dev, ret,
+					     "failed to read color for %pfw\n",
+					     fwnode);
+	}
+
+	if (color == LED_COLOR_ID_RGB || color == LED_COLOR_ID_MULTI) {
+		if (!count)
+			return dev_err_probe(chip->dev, -EINVAL,
+					     "multicolor LED %pfw has no components\n",
+					     fwnode);
+
+		return is32fl3207_register_multicolor(chip, fwnode, led);
+	}
+
+	if (count)
+		return dev_err_probe(chip->dev, -EINVAL,
+				     "single LED %pfw must not have components\n",
+				     fwnode);
+
+	return is32fl3207_register_single(chip, fwnode, led);
+}
+
+static int is32fl3207_clear_retained_scaling(struct is32fl3207 *chip)
+{
+	u8 scaling[IS32FL3207_NUM_CHANNELS] = { };
+	int ret;
+
+	ret = regmap_write(chip->regmap, IS32FL3207_REG_CONTROL, 0);
+	if (ret)
+		return ret;
+
+	return regmap_bulk_write(chip->regmap,
+				 IS32FL3207_REG_SCALING(0), scaling,
+				 sizeof(scaling));
+}
+
+static int is32fl3207_hw_init(struct is32fl3207 *chip)
+{
+	u8 scaling[IS32FL3207_NUM_CHANNELS] = { };
+	u8 pwm[2 * IS32FL3207_NUM_CHANNELS] = { };
+	int disable_ret;
+	int ret;
+
+	/* Software reset requires normal operation (SSD = 1). */
+	ret = regmap_write(chip->regmap, IS32FL3207_REG_CONTROL,
+			   IS32FL3207_CONTROL_ENABLE);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(chip->regmap, IS32FL3207_REG_RESET, 0);
+	if (ret)
+		return ret;
+	usleep_range(200, 300);
+
+	ret = regmap_write(chip->regmap, IS32FL3207_REG_CONTROL, 0);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(chip->regmap, IS32FL3207_REG_GLOBAL_CURRENT,
+			   IS32FL3207_GLOBAL_CURRENT_MAX);
+	if (ret)
+		return ret;
+
+	ret = regmap_bulk_write(chip->regmap, IS32FL3207_REG_SCALING(0),
+				scaling, sizeof(scaling));
+	if (ret)
+		return ret;
+
+	ret = regmap_bulk_write(chip->regmap, IS32FL3207_REG_PWM_LOW(0), pwm,
+				sizeof(pwm));
+	if (ret)
+		return ret;
+
+	/* PWM data can be latched only in normal operation. */
+	ret = regmap_write(chip->regmap, IS32FL3207_REG_CONTROL,
+			   IS32FL3207_CONTROL_ENABLE);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(chip->regmap, IS32FL3207_REG_PWM_UPDATE, 0);
+	disable_ret = regmap_write(chip->regmap, IS32FL3207_REG_CONTROL, 0);
+
+	return ret ?: disable_ret;
+}
+
+static int is32fl3207_enable(struct is32fl3207 *chip)
+{
+	int ret;
+
+	guard(mutex)(&chip->lock);
+
+	ret = regmap_write(chip->regmap, IS32FL3207_REG_CONTROL,
+			   IS32FL3207_CONTROL_ENABLE);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(chip->regmap, IS32FL3207_REG_PWM_UPDATE, 0);
+	if (ret)
+		regmap_write(chip->regmap, IS32FL3207_REG_CONTROL, 0);
+
+	return ret;
+}
+
+static void is32fl3207_disable_locked(struct is32fl3207 *chip)
+{
+	regmap_write(chip->regmap, IS32FL3207_REG_CONTROL, 0);
+	if (chip->enable_gpio)
+		gpiod_set_value_cansleep(chip->enable_gpio, 0);
+}
+
+static void is32fl3207_disable(void *data)
+{
+	struct is32fl3207 *chip = data;
+
+	guard(mutex)(&chip->lock);
+	chip->shutting_down = true;
+	is32fl3207_disable_locked(chip);
+}
+
+static const struct regmap_config is32fl3207_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = IS32FL3207_REG_RESET,
+};
+
+static int is32fl3207_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct is32fl3207 *ddata;
+	unsigned int count;
+	unsigned int i = 0;
+	u32 riset_ohms;
+	int ret;
+
+	count = device_get_child_node_count(dev);
+	if (!count || count > IS32FL3207_NUM_CHANNELS)
+		return dev_err_probe(dev, -EINVAL,
+				     "invalid LED count %u\n", count);
+
+	ddata = devm_kzalloc(dev, struct_size(ddata, leds, count), GFP_KERNEL);
+	if (!ddata)
+		return -ENOMEM;
+
+	ddata->dev = dev;
+	ddata->num_leds = count;
+	i2c_set_clientdata(client, ddata);
+
+	ret = device_property_read_u32(dev, "issi,riset-ohms", &riset_ohms);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to read RISET value\n");
+
+	if (riset_ohms < 2000)
+		return dev_err_probe(dev, -EINVAL,
+				     "RISET value %u is below 2000 ohms\n",
+				     riset_ohms);
+
+	ddata->output_max_microamp = div_u64(IS32FL3207_CURRENT_NUMERATOR,
+					     riset_ohms);
+	if (!ddata->output_max_microamp)
+		return dev_err_probe(dev, -EINVAL,
+				     "RISET value %u is too large\n",
+				     riset_ohms);
+
+	ddata->enable_gpio = devm_gpiod_get_optional(dev, "enable",
+						     GPIOD_OUT_LOW);
+	if (IS_ERR(ddata->enable_gpio))
+		return dev_err_probe(dev, PTR_ERR(ddata->enable_gpio),
+				     "failed to get enable GPIO\n");
+
+	ddata->regmap = devm_regmap_init_i2c(client,
+					     &is32fl3207_regmap_config);
+	if (IS_ERR(ddata->regmap))
+		return dev_err_probe(dev, PTR_ERR(ddata->regmap),
+				     "failed to allocate register map\n");
+
+	ret = devm_mutex_init(dev, &ddata->lock);
+	if (ret)
+		return ret;
+
+	ret = devm_regulator_get_enable_optional(dev, "vcc");
+	if (ret && ret != -ENODEV)
+		return dev_err_probe(dev, ret,
+				     "failed to enable VCC regulator\n");
+
+	ret = devm_add_action_or_reset(dev, is32fl3207_disable, ddata);
+	if (ret)
+		return ret;
+
+	/* Let VCC settle while SDB keeps the outputs disabled. */
+	usleep_range(1000, 2000);
+
+	/*
+	 * Registers remain accessible with SDB low. Clear retained scaling
+	 * before releasing hardware shutdown.
+	 */
+	ret = is32fl3207_clear_retained_scaling(ddata);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "failed to clear retained current scaling\n");
+
+	if (ddata->enable_gpio)
+		gpiod_set_value_cansleep(ddata->enable_gpio, 1);
+
+	/* The SDB rising edge resets the I2C interface; allow it to settle. */
+	usleep_range(1000, 2000);
+
+	ret = is32fl3207_hw_init(ddata);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "failed to initialize controller\n");
+
+	device_for_each_child_node_scoped(dev, child) {
+		struct is32fl3207_led *led = &ddata->leds[i];
+
+		ret = is32fl3207_register_led(ddata, child, led);
+		if (ret)
+			return ret;
+
+		i++;
+	}
+
+	ret = is32fl3207_enable(ddata);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to enable controller\n");
+
+	return 0;
+}
+
+static void is32fl3207_shutdown(struct i2c_client *client)
+{
+	struct is32fl3207 *chip = i2c_get_clientdata(client);
+	bool retain_state = false;
+	unsigned int i;
+	int ret = 0;
+
+	guard(mutex)(&chip->lock);
+	chip->shutting_down = true;
+
+	for (i = 0; i < chip->num_leds; i++)
+		if (chip->leds[i].led_cdev->flags & LED_RETAIN_AT_SHUTDOWN) {
+			retain_state = true;
+			break;
+		}
+
+	if (!retain_state) {
+		is32fl3207_disable_locked(chip);
+		return;
+	}
+
+	for (i = 0; i < chip->num_leds; i++) {
+		struct led_classdev *cdev = chip->leds[i].led_cdev;
+
+		if (cdev->flags & LED_RETAIN_AT_SHUTDOWN)
+			continue;
+		ret = is32fl3207_turn_off_locked(chip, &chip->leds[i]);
+
+		if (ret) {
+			dev_warn(chip->dev,
+				 "failed to turn off LEDs during shutdown: %d\n",
+				 ret);
+			break;
+		}
+	}
+}
+
+static const struct of_device_id is32fl3207_of_match[] = {
+	{ .compatible = "issi,is32fl3207" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, is32fl3207_of_match);
+
+static const struct i2c_device_id is32fl3207_id[] = {
+	{ .name = "is32fl3207" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, is32fl3207_id);
+
+static struct i2c_driver is32fl3207_driver = {
+	.driver = {
+		.name = "is32fl3207",
+		.of_match_table = is32fl3207_of_match,
+	},
+	.probe = is32fl3207_probe,
+	.shutdown = is32fl3207_shutdown,
+	.id_table = is32fl3207_id,
+};
+module_i2c_driver(is32fl3207_driver);
+
+MODULE_AUTHOR("Ahmad Byagowi <ahmadexp@gmail.com>");
+MODULE_DESCRIPTION("Lumissil IS32FL3207 LED controller driver");
+MODULE_LICENSE("GPL");
-- 
2.50.1 (Apple Git-155)

Re: [PATCH v6 2/2] leds: is32fl3207: Add controller driver

[sashiko-bot]

> Add an I2C driver for the Lumissil IS32FL3207 18-channel LED controller.
> 
> Expose individual and multicolor LEDs through the LED class. Use the
> default 8-bit, 62 kHz PWM mode, derive output current from RISET, and
> enforce each output current limit with the scaling registers. Serialize
> multicolor calculation, scaling, PWM, and controller-wide update
> operations.
> 
> Clear retained scaling while SDB holds the outputs disabled. Release SDB
> and briefly enable normal operation to issue the required software reset,
> then keep the controller in software shutdown while registering every LED.
> Enable outputs only after all limits and initial brightness values are
> programmed.
> 
> Handle an optional supply and enable GPIO. Serialize shutdown against
> pending brightness updates and honor retained shutdown state.
> 
> Signed-off-by: Ahmad Byagowi <ahmadexp@gmail.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/cover.1787247467.git.ahmadexp@gmail.com?part=2

Re: [PATCH v6 1/2] dt-bindings: leds: Add IS32FL3207 controller

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The `minimum: 149` constraint on `led-max-microamp` incorrectly rejects valid, lower-current configurations.
--

--- Patch [1]: [PATCH v6 1/2] dt-bindings: leds: Add IS32FL3207 controller ---
commit 4fc20b49cd66c5af5de8db1465fd9c2b64f3c2ad
Author: Ahmad Byagowi <ahmadexp@gmail.com>

dt-bindings: leds: Add IS32FL3207 controller

The IS32FL3207 is an 18-channel constant-current LED controller with
per-output PWM and current scaling.

> diff --git a/Documentation/devicetree/bindings/leds/issi,is32fl3207.yaml b/Documentation/devicetree/bindings/leds/issi,is32fl3207.yaml
> new file mode 100644
> index 0000000000000..32eaf14ca7cf3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/issi,is32fl3207.yaml
> @@ -0,0 +1,285 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/leds/issi,is32fl3207.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Lumissil IS32FL3207 18-channel LED controller

[ ... ]

> +patternProperties:
> +  "^led@[0-9a-f]+$":
> +    type: object
> +    $ref: common.yaml#
> +    unevaluatedProperties: false
> +
> +    properties:
> +      reg:
> +        minimum: 0
> +        maximum: 17
> +        description: |
> +          Zero-based LED output number. Values 0 through 17 correspond to
> +          OUT1 through OUT18.
> +
> +      led-max-microamp:
> +        minimum: 149
> +        maximum: 38250

[Severity: Medium]
Does this minimum constraint inadvertently reject valid lower-current limits
for single LEDs?

When a board designer uses a larger issi,riset-ohms (e.g., 100 kOhm) to
achieve a lower full-scale current, they may need to limit a specific LED to
a peak current well below 149 uA (e.g., 50 uA).

Since the hardware can represent much smaller currents with a large RISET,
could this prevent developers from enforcing valid safety limits below 149 uA,
forcing them to over-specify the limit?

> +        description: |
> +          Board-safe peak current for this output. The value must not exceed
> +          the full-scale current derived from issi,riset-ohms. The minimum is
> +          the smallest nonzero current representable at the maximum permitted
> +          full-scale current.

[ ... ]

> +  "^multi-led(@[0-9a-f]|-[0-9]+)?$":
> +    type: object
> +    $ref: leds-class-multicolor.yaml#
> +    unevaluatedProperties: false

[ ... ]

> +    patternProperties:
> +      "^led@[0-9a-f]+$":
> +        type: object
> +        $ref: common.yaml#
> +        unevaluatedProperties: false
> +
> +        properties:
> +          reg:
> +            minimum: 0
> +            maximum: 17
> +            description: |
> +              Zero-based LED output number. Values 0 through 17 correspond to
> +              OUT1 through OUT18.
> +
> +          led-max-microamp:
> +            minimum: 149
> +            maximum: 38250

[Severity: Medium]
Does this also incorrectly restrict nested LEDs inside multi-led groups from
having valid maximum current limits below 149 uA?

> +            description: |
> +              Board-safe peak current for this output. The value must not
> +              exceed the full-scale current derived from issi,riset-ohms. The
> +              minimum is the smallest nonzero current representable at the
> +              maximum permitted full-scale current.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/cover.1787247467.git.ahmadexp@gmail.com?part=1