[PATCH v5 0/2] leds: Add a driver for KTD202x

[PATCH v5 0/2] leds: Add a driver for KTD202x

[André Apitzsch]

Add the binding description and the corresponding driver for
the Kinetic KTD2026 and KTD2027.

Signed-off-by: André Apitzsch <git@apitzsch.eu>
---
Changes in v5:
- Restructure brightness_set() + add comments to it to be easier understandable
- Add some line breaks + remove little line-wraps to improve readability
- Move parts of add_led() to setup_led_{rgb,single}()
- Move mutex_init() to the end of probe to omit gotos
- Fix grammar
- Set initial intensity to max brightness to avoid LED staying off when
  brightness is changed after switching to timer trigger, because of zero
  intensity
- Link to v4: https://lore.kernel.org/r/20230923-ktd202x-v4-0-14f724f6d43b@apitzsch.eu

Changes in v4:
- Annotate struct ktd202x with __counted_by
- Link to v3: https://lore.kernel.org/r/20230906-ktd202x-v3-0-7fcb91c65d3a@apitzsch.eu

Changes in v3:
- Add r-b to bindings patch
- Replace .probe_new by .probe
- Link to v2: https://lore.kernel.org/r/20230901-ktd202x-v2-0-3cb8b0ca02ed@apitzsch.eu

Changes in v2:
- Make binding description filename match compatible
- Address comments by Lee Jones
  - Extend driver description in Kconfig
  - Add copyright + link to datasheet
  - Add unit to definition/variable names, where needed
  - Define magic numbers
  - Remove forward declaration of 'struct ktd202x'
  - Remove superfluous comments
  - Get rid of struct ktd202x_info
  - Join ktd202x_chip_init() with ktd202x_chip_enable()
  - Return the error on ktd202x_chip_disable()
  - Remove unreachable case from chip_in_use()
  - Rename ktd202x_brightness_set() argument from num_colors to num_channels
  - Forward errors received in ktd202x_brightness_set()
  - Remove variable for 'num_channels = 1'
  - Add some explanations to blink time calculation
  - Remove unneeded lcdev from ktd202x_blink_*_set()
  - Add define for max brightness and replace deprecated LED_FULL by it
  - Move setting led_classdev.brightness to ktd202x_brightness_*_set()
  - Move mutex_lock inside ktd202x_blink_set()
  - Add comment that 'color' property is optional (allow EINVAL)
  - Replace escaped double quotes by single quotes
  - Avoid overloading variable 'color'
  - Do not lock during probe
  - Remove usage of 'of_match_ptr'
- Document interrupt and pull-up supply, like done for aw2013[1]
- Fix error in num_steps calculation
- Link to v1: https://lore.kernel.org/r/20230618-ktd202x-v1-0-fc182fefadd7@apitzsch.eu

[1] https://lore.kernel.org/linux-leds/20230815-aw2013-vio-v3-0-2505296b0856@gerhold.net/

---
André Apitzsch (2):
      dt-bindings: leds: Add Kinetic KTD2026/2027 LED
      leds: add ktd202x driver

 .../devicetree/bindings/leds/kinetic,ktd202x.yaml  | 171 ++++++
 drivers/leds/rgb/Kconfig                           |  13 +
 drivers/leds/rgb/Makefile                          |   1 +
 drivers/leds/rgb/leds-ktd202x.c                    | 619 +++++++++++++++++++++
 4 files changed, 804 insertions(+)
---
base-commit: 165adeea3617ea22dc49f8880474ebf3a98b696d
change-id: 20230618-ktd202x-546b2a7d240b

Best regards,
-- 
André Apitzsch <git@apitzsch.eu>

[PATCH v5 1/2] dt-bindings: leds: Add Kinetic KTD2026/2027 LED

[André Apitzsch]

Document Kinetic KTD2026/2027 LED driver devicetree bindings.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: André Apitzsch <git@apitzsch.eu>
---
 .../devicetree/bindings/leds/kinetic,ktd202x.yaml  | 171 +++++++++++++++++++++
 1 file changed, 171 insertions(+)

diff --git a/Documentation/devicetree/bindings/leds/kinetic,ktd202x.yaml b/Documentation/devicetree/bindings/leds/kinetic,ktd202x.yaml
new file mode 100644
index 000000000000..832c030a5acf
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/kinetic,ktd202x.yaml
@@ -0,0 +1,171 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/kinetic,ktd202x.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Kinetic KTD2026/7 RGB/White LED Driver
+
+maintainers:
+  - André Apitzsch <git@apitzsch.eu>
+
+description: |
+  The KTD2026/7 is a RGB/White LED driver with I2C interface.
+
+  The data sheet can be found at:
+    https://www.kinet-ic.com/uploads/KTD2026-7-04h.pdf
+
+properties:
+  compatible:
+    enum:
+      - kinetic,ktd2026
+      - kinetic,ktd2027
+
+  reg:
+    maxItems: 1
+
+  vin-supply:
+    description: Regulator providing power to the "VIN" pin.
+
+  vio-supply:
+    description: Regulator providing power for pull-up of the I/O lines.
+      Note that this regulator does not directly connect to KTD2026, but is
+      needed for the correct operation of the status ("ST") and I2C lines.
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+  multi-led:
+    type: object
+    $ref: leds-class-multicolor.yaml#
+    unevaluatedProperties: false
+
+    properties:
+      "#address-cells":
+        const: 1
+
+      "#size-cells":
+        const: 0
+
+    patternProperties:
+      "^led@[0-3]$":
+        type: object
+        $ref: common.yaml#
+        unevaluatedProperties: false
+
+        properties:
+          reg:
+            description: Index of the LED.
+            minimum: 0
+            maximum: 3
+
+        required:
+          - reg
+          - color
+
+    required:
+      - "#address-cells"
+      - "#size-cells"
+
+patternProperties:
+  "^led@[0-3]$":
+    type: object
+    $ref: common.yaml#
+    unevaluatedProperties: false
+
+    properties:
+      reg:
+        description: Index of the LED.
+        minimum: 0
+        maximum: 3
+
+    required:
+      - reg
+
+required:
+  - compatible
+  - reg
+  - "#address-cells"
+  - "#size-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/leds/common.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        led-controller@30 {
+            compatible = "kinetic,ktd2026";
+            reg = <0x30>;
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            vin-supply = <&pm8916_l17>;
+            vio-supply = <&pm8916_l6>;
+
+            led@0 {
+                reg = <0>;
+                function = LED_FUNCTION_STATUS;
+                color = <LED_COLOR_ID_RED>;
+            };
+
+            led@1 {
+                reg = <1>;
+                function = LED_FUNCTION_STATUS;
+                color = <LED_COLOR_ID_GREEN>;
+            };
+
+            led@2 {
+                reg = <2>;
+                function = LED_FUNCTION_STATUS;
+                color = <LED_COLOR_ID_BLUE>;
+            };
+        };
+    };
+  - |
+    #include <dt-bindings/leds/common.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        led-controller@30 {
+            compatible = "kinetic,ktd2026";
+            reg = <0x30>;
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            vin-supply = <&pm8916_l17>;
+            vio-supply = <&pm8916_l6>;
+
+            multi-led {
+                color = <LED_COLOR_ID_RGB>;
+                function = LED_FUNCTION_STATUS;
+
+                #address-cells = <1>;
+                #size-cells = <0>;
+
+                led@0 {
+                    reg = <0>;
+                    color = <LED_COLOR_ID_RED>;
+                };
+
+                led@1 {
+                    reg = <1>;
+                    color = <LED_COLOR_ID_GREEN>;
+                };
+
+                led@2 {
+                    reg = <2>;
+                    color = <LED_COLOR_ID_BLUE>;
+                };
+            };
+        };
+    };

-- 
2.42.0

[PATCH v5 2/2] leds: add ktd202x driver

[André Apitzsch]

This commit adds support for Kinetic KTD2026/7 RGB/White LED driver.

Signed-off-by: André Apitzsch <git@apitzsch.eu>
---
 drivers/leds/rgb/Kconfig        |  13 +
 drivers/leds/rgb/Makefile       |   1 +
 drivers/leds/rgb/leds-ktd202x.c | 619 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 633 insertions(+)

diff --git a/drivers/leds/rgb/Kconfig b/drivers/leds/rgb/Kconfig
index 183bccc06cf3..a6a21f564673 100644
--- a/drivers/leds/rgb/Kconfig
+++ b/drivers/leds/rgb/Kconfig
@@ -14,6 +14,19 @@ config LEDS_GROUP_MULTICOLOR
 	  To compile this driver as a module, choose M here: the module
 	  will be called leds-group-multicolor.
 
+config LEDS_KTD202X
+	tristate "LED support for KTD202x Chips"
+	depends on I2C
+	depends on OF
+	select REGMAP_I2C
+	help
+	  This option enables support for the Kinetic KTD2026/KTD2027
+	  RGB/White LED driver found in different BQ mobile phones.
+	  It is a 3 or 4 channel LED driver programmed via an I2C interface.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called leds-ktd202x.
+
 config LEDS_PWM_MULTICOLOR
 	tristate "PWM driven multi-color LED Support"
 	depends on PWM
diff --git a/drivers/leds/rgb/Makefile b/drivers/leds/rgb/Makefile
index c11cc56384e7..243f31e4d70d 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_KTD202X)		+= leds-ktd202x.o
 obj-$(CONFIG_LEDS_PWM_MULTICOLOR)	+= leds-pwm-multicolor.o
 obj-$(CONFIG_LEDS_QCOM_LPG)		+= leds-qcom-lpg.o
 obj-$(CONFIG_LEDS_MT6370_RGB)		+= leds-mt6370-rgb.o
diff --git a/drivers/leds/rgb/leds-ktd202x.c b/drivers/leds/rgb/leds-ktd202x.c
new file mode 100644
index 000000000000..57f69d2c30f8
--- /dev/null
+++ b/drivers/leds/rgb/leds-ktd202x.c
@@ -0,0 +1,619 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Kinetic KTD2026/7 RGB/White LED driver with I2C interface
+ *
+ * Copyright 2023 André Apitzsch <git@apitzsch.eu>
+ *
+ * Datasheet: https://www.kinet-ic.com/uploads/KTD2026-7-04h.pdf
+ */
+
+#include <linux/i2c.h>
+#include <linux/led-class-multicolor.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+
+#define KTD2026_NUM_LEDS 3
+#define KTD2027_NUM_LEDS 4
+#define KTD202X_MAX_LEDS 4
+
+/* Register bank */
+#define KTD202X_REG_RESET_CONTROL	0x00
+#define KTD202X_REG_FLASH_PERIOD	0x01
+#define KTD202X_REG_PWM1_TIMER		0x02
+#define KTD202X_REG_PWM2_TIMER		0x03
+#define KTD202X_REG_CHANNEL_CTRL	0x04
+#define KTD202X_REG_TRISE_FALL		0x05
+#define KTD202X_REG_LED_IOUT(x)		(0x06 + (x))
+
+/* Register 0 */
+#define KTD202X_TIMER_SLOT_CONTROL_TSLOT1	0x00
+#define KTD202X_TIMER_SLOT_CONTROL_TSLOT2	0x01
+#define KTD202X_TIMER_SLOT_CONTROL_TSLOT3	0x02
+#define KTD202X_TIMER_SLOT_CONTROL_TSLOT4	0x03
+#define KTD202X_RSTR_RESET			0x07
+
+#define KTD202X_ENABLE_CTRL_WAKE	0x00 /* SCL High & SDA High */
+#define KTD202X_ENABLE_CTRL_SLEEP	0x08 /* SCL High & SDA Toggling */
+
+#define KTD202X_TRISE_FALL_SCALE_NORMAL		0x00
+#define KTD202X_TRISE_FALL_SCALE_SLOW_X2	0x20
+#define KTD202X_TRISE_FALL_SCALE_SLOW_X4	0x40
+#define KTD202X_TRISE_FALL_SCALE_FAST_X8	0x60
+
+/* Register 1 */
+#define KTD202X_FLASH_PERIOD_256_MS_LOG_RAMP	0x00
+
+/* Register 2-3 */
+#define KTD202X_FLASH_ON_TIME_0_4_PERCENT	0x01
+
+/* Register 4 */
+#define KTD202X_CHANNEL_CTRL_MASK(x) (BIT(2 * (x)) | BIT(2 * (x) + 1))
+#define KTD202X_CHANNEL_CTRL_OFF 0x00
+#define KTD202X_CHANNEL_CTRL_ON(x) BIT(2 * (x))
+#define KTD202X_CHANNEL_CTRL_PWM1(x) BIT(2 * (x) + 1)
+#define KTD202X_CHANNEL_CTRL_PWM2(x) (BIT(2 * (x)) | BIT(2 * (x) + 1))
+
+/* Register 5 */
+#define KTD202X_RAMP_TIMES_2_MS			0x00
+
+/* Register 6-9 */
+#define KTD202X_LED_CURRENT_10_mA		0x4f
+
+#define KTD202X_FLASH_PERIOD_MIN_MS 256
+#define KTD202X_FLASH_PERIOD_STEP_MS 128
+#define KTD202X_FLASH_PERIOD_MAX_STEPS 126
+#define KTD202X_FLASH_ON_MAX 256
+
+#define KTD202X_MAX_BRIGHTNESS 192
+
+static const struct reg_default ktd202x_reg_defaults[] = {
+	{ KTD202X_REG_RESET_CONTROL, KTD202X_TIMER_SLOT_CONTROL_TSLOT1 |
+		KTD202X_ENABLE_CTRL_WAKE | KTD202X_TRISE_FALL_SCALE_NORMAL },
+	{ KTD202X_REG_FLASH_PERIOD, KTD202X_FLASH_PERIOD_256_MS_LOG_RAMP },
+	{ KTD202X_REG_PWM1_TIMER, KTD202X_FLASH_ON_TIME_0_4_PERCENT },
+	{ KTD202X_REG_PWM2_TIMER, KTD202X_FLASH_ON_TIME_0_4_PERCENT },
+	{ KTD202X_REG_CHANNEL_CTRL, KTD202X_CHANNEL_CTRL_OFF },
+	{ KTD202X_REG_TRISE_FALL, KTD202X_RAMP_TIMES_2_MS },
+	{ KTD202X_REG_LED_IOUT(0), KTD202X_LED_CURRENT_10_mA },
+	{ KTD202X_REG_LED_IOUT(1), KTD202X_LED_CURRENT_10_mA },
+	{ KTD202X_REG_LED_IOUT(2), KTD202X_LED_CURRENT_10_mA },
+	{ KTD202X_REG_LED_IOUT(3), KTD202X_LED_CURRENT_10_mA },
+};
+
+struct ktd202x_led {
+	struct ktd202x *chip;
+	union {
+		struct led_classdev cdev;
+		struct led_classdev_mc mcdev;
+	};
+	u32 index;
+};
+
+struct ktd202x {
+	struct mutex mutex;
+	struct regulator_bulk_data regulators[2];
+	struct device *dev;
+	struct regmap *regmap;
+	bool enabled;
+	int num_leds;
+	struct ktd202x_led leds[] __counted_by(num_leds);
+};
+
+static int ktd202x_chip_disable(struct ktd202x *chip)
+{
+	int ret;
+
+	if (!chip->enabled)
+		return 0;
+
+	regmap_write(chip->regmap, KTD202X_REG_RESET_CONTROL, KTD202X_ENABLE_CTRL_SLEEP);
+
+	ret = regulator_bulk_disable(ARRAY_SIZE(chip->regulators), chip->regulators);
+	if (ret) {
+		dev_err(chip->dev, "Failed to disable regulators: %d\n", ret);
+		return ret;
+	}
+
+	chip->enabled = false;
+	return 0;
+}
+
+static int ktd202x_chip_enable(struct ktd202x *chip)
+{
+	int ret;
+
+	if (chip->enabled)
+		return 0;
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(chip->regulators), chip->regulators);
+	if (ret) {
+		dev_err(chip->dev, "Failed to enable regulators: %d\n", ret);
+		return ret;
+	}
+	chip->enabled = true;
+
+	ret = regmap_write(chip->regmap, KTD202X_REG_RESET_CONTROL, KTD202X_ENABLE_CTRL_WAKE);
+
+	if (ret) {
+		dev_err(chip->dev, "Failed to enable the chip: %d\n", ret);
+		ktd202x_chip_disable(chip);
+	}
+
+	return ret;
+}
+
+static bool ktd202x_chip_in_use(struct ktd202x *chip)
+{
+	int i;
+
+	for (i = 0; i < chip->num_leds; i++) {
+		if (chip->leds[i].cdev.brightness)
+			return true;
+	}
+
+	return false;
+}
+
+static int ktd202x_brightness_set(struct ktd202x_led *led,
+				  struct mc_subled *subleds,
+				  unsigned int num_channels)
+{
+	enum led_brightness brightness;
+	bool mode_blink = false;
+	int channel_state;
+	int channel;
+	int state;
+	int mode;
+	int ret;
+	int i;
+
+	if (ktd202x_chip_in_use(led->chip)) {
+		ret = ktd202x_chip_enable(led->chip);
+		if (ret)
+			return ret;
+	}
+
+	ret = regmap_read(led->chip->regmap, KTD202X_REG_CHANNEL_CTRL, &state);
+	if (ret)
+		return ret;
+
+	/*
+	 * In multicolor case, assume blink mode if PWM is set for at least one
+	 * channel because another channel cannot be in state ON at the same time
+	 */
+	for (i = 0; i < num_channels; i++) {
+		channel = subleds[i].channel;
+		channel_state = (state >> 2 * channel) & KTD202X_CHANNEL_CTRL_MASK(0);
+		if (channel_state == KTD202X_CHANNEL_CTRL_OFF)
+			continue;
+		mode_blink = channel_state == KTD202X_CHANNEL_CTRL_PWM1(0);
+		break;
+	}
+
+	for (i = 0; i < num_channels; i++) {
+		brightness = subleds[i].brightness;
+		channel = subleds[i].channel;
+
+		if (brightness) {
+			/* Register expects brightness between 0 and MAX_BRIGHTNESS - 1 */
+			ret = regmap_write(led->chip->regmap, KTD202X_REG_LED_IOUT(channel),
+					   brightness - 1);
+			if (ret)
+				return ret;
+
+			if (mode_blink)
+				mode = KTD202X_CHANNEL_CTRL_PWM1(channel);
+			else
+				mode = KTD202X_CHANNEL_CTRL_ON(channel);
+		} else {
+			mode = KTD202X_CHANNEL_CTRL_OFF;
+		}
+		ret = regmap_update_bits(led->chip->regmap, KTD202X_REG_CHANNEL_CTRL,
+					 KTD202X_CHANNEL_CTRL_MASK(channel), mode);
+		if (ret)
+			return ret;
+	}
+
+	if (!ktd202x_chip_in_use(led->chip))
+		return ktd202x_chip_disable(led->chip);
+
+	return 0;
+}
+
+static int ktd202x_brightness_single_set(struct led_classdev *cdev,
+					 enum led_brightness value)
+{
+	struct ktd202x_led *led = container_of(cdev, struct ktd202x_led, cdev);
+	struct mc_subled info;
+	int ret;
+
+	cdev->brightness = value;
+
+	mutex_lock(&led->chip->mutex);
+
+	info.brightness = value;
+	info.channel = led->index;
+	ret = ktd202x_brightness_set(led, &info, 1);
+
+	mutex_unlock(&led->chip->mutex);
+
+	return ret;
+}
+
+static int ktd202x_brightness_mc_set(struct led_classdev *cdev,
+				     enum led_brightness value)
+{
+	struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
+	struct ktd202x_led *led = container_of(mc, struct ktd202x_led, mcdev);
+	int ret;
+
+	cdev->brightness = value;
+
+	mutex_lock(&led->chip->mutex);
+
+	led_mc_calc_color_components(mc, value);
+	ret = ktd202x_brightness_set(led, mc->subled_info, mc->num_colors);
+
+	mutex_unlock(&led->chip->mutex);
+
+	return ret;
+}
+
+static int ktd202x_blink_set(struct ktd202x_led *led, unsigned long *delay_on,
+			     unsigned long *delay_off, struct mc_subled *subleds,
+			     unsigned int num_channels)
+{
+	unsigned long delay_total_ms;
+	int ret, num_steps, on;
+	u8 ctrl_mask = 0;
+	u8 ctrl_pwm1 = 0;
+	u8 ctrl_on = 0;
+	int i, channel;
+
+	mutex_lock(&led->chip->mutex);
+
+	for (i = 0; i < num_channels; i++) {
+		channel = subleds[i].channel;
+		ctrl_mask |= KTD202X_CHANNEL_CTRL_MASK(channel);
+		ctrl_on |= KTD202X_CHANNEL_CTRL_ON(channel);
+		ctrl_pwm1 |= KTD202X_CHANNEL_CTRL_PWM1(channel);
+	}
+
+	/* Never off - brightness is already set, disable blinking */
+	if (!*delay_off) {
+		ret = regmap_update_bits(led->chip->regmap, KTD202X_REG_CHANNEL_CTRL,
+					 ctrl_mask, ctrl_on);
+		goto out;
+	}
+
+	/* Convert into values the HW will understand. */
+
+	/* Integer representation of time of flash period */
+	num_steps = (*delay_on + *delay_off - KTD202X_FLASH_PERIOD_MIN_MS) /
+		    KTD202X_FLASH_PERIOD_STEP_MS;
+	num_steps = clamp(num_steps, 0, KTD202X_FLASH_PERIOD_MAX_STEPS);
+
+	/* Integer representation of percentage of LED ON time */
+	on = (*delay_on * KTD202X_FLASH_ON_MAX) / (*delay_on + *delay_off);
+
+	/* Actually used delay_{on,off} values */
+	delay_total_ms = num_steps * KTD202X_FLASH_PERIOD_STEP_MS + KTD202X_FLASH_PERIOD_MIN_MS;
+	*delay_on = (delay_total_ms * on) / KTD202X_FLASH_ON_MAX;
+	*delay_off = delay_total_ms - *delay_on;
+
+	/* Set timings */
+	ret = regmap_write(led->chip->regmap, KTD202X_REG_FLASH_PERIOD, num_steps);
+	if (ret)
+		goto out;
+
+	ret = regmap_write(led->chip->regmap, KTD202X_REG_PWM1_TIMER, on);
+	if (ret)
+		goto out;
+
+	ret = regmap_update_bits(led->chip->regmap, KTD202X_REG_CHANNEL_CTRL,
+				 ctrl_mask, ctrl_pwm1);
+out:
+	mutex_unlock(&led->chip->mutex);
+	return ret;
+}
+
+static int ktd202x_blink_single_set(struct led_classdev *cdev,
+				    unsigned long *delay_on,
+				    unsigned long *delay_off)
+{
+	struct ktd202x_led *led = container_of(cdev, struct ktd202x_led, cdev);
+	struct mc_subled info;
+	int ret;
+
+	if (!cdev->brightness) {
+		ret = ktd202x_brightness_single_set(cdev, KTD202X_MAX_BRIGHTNESS);
+		if (ret)
+			return ret;
+	}
+
+	/* If no blink specified, default to 1 Hz. */
+	if (!*delay_off && !*delay_on) {
+		*delay_off = 500;
+		*delay_on = 500;
+	}
+
+	/* Never on - just set to off */
+	if (!*delay_on)
+		return ktd202x_brightness_single_set(cdev, LED_OFF);
+
+	info.channel = led->index;
+
+	return ktd202x_blink_set(led, delay_on, delay_off, &info, 1);
+}
+
+static int ktd202x_blink_mc_set(struct led_classdev *cdev,
+				unsigned long *delay_on,
+				unsigned long *delay_off)
+{
+	struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
+	struct ktd202x_led *led = container_of(mc, struct ktd202x_led, mcdev);
+	int ret;
+
+	if (!cdev->brightness) {
+		ret = ktd202x_brightness_mc_set(cdev, KTD202X_MAX_BRIGHTNESS);
+		if (ret)
+			return ret;
+	}
+
+	/* If no blink specified, default to 1 Hz. */
+	if (!*delay_off && !*delay_on) {
+		*delay_off = 500;
+		*delay_on = 500;
+	}
+
+	/* Never on - just set to off */
+	if (!*delay_on)
+		return ktd202x_brightness_mc_set(cdev, LED_OFF);
+
+	return ktd202x_blink_set(led, delay_on, delay_off, mc->subled_info,
+				 mc->num_colors);
+}
+
+static int ktd202x_setup_led_rgb(struct ktd202x *chip, struct device_node *np,
+				 struct ktd202x_led *led, struct led_init_data *init_data)
+{
+	struct led_classdev *cdev;
+	struct device_node *child;
+	struct mc_subled *info;
+	int num_channels;
+	int i = 0;
+	u32 reg;
+	int ret;
+
+	num_channels = of_get_available_child_count(np);
+	if (!num_channels || num_channels > chip->num_leds)
+		return -EINVAL;
+
+	info = devm_kcalloc(chip->dev, num_channels, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	for_each_available_child_of_node(np, child) {
+		u32 mono_color = 0;
+
+		ret = of_property_read_u32(child, "reg", &reg);
+		if (ret != 0 || reg >= chip->num_leds) {
+			dev_err(chip->dev, "invalid 'reg' of %pOFn\n", np);
+			return -EINVAL;
+		}
+
+		ret = of_property_read_u32(child, "color", &mono_color);
+		if (ret < 0 && ret != -EINVAL) {
+			dev_err(chip->dev, "failed to parse 'color' of %pOF\n", np);
+			return ret;
+		}
+
+		info[i].color_index = mono_color;
+		info[i].channel = reg;
+		info[i].intensity = KTD202X_MAX_BRIGHTNESS;
+		i++;
+	}
+
+	led->mcdev.subled_info = info;
+	led->mcdev.num_colors = num_channels;
+
+	cdev = &led->mcdev.led_cdev;
+	cdev->brightness_set_blocking = ktd202x_brightness_mc_set;
+	cdev->blink_set = ktd202x_blink_mc_set;
+
+	return devm_led_classdev_multicolor_register_ext(chip->dev, &led->mcdev, init_data);
+}
+
+static int ktd202x_setup_led_single(struct ktd202x *chip, struct device_node *np,
+				    struct ktd202x_led *led, struct led_init_data *init_data)
+{
+	struct led_classdev *cdev;
+	u32 reg;
+	int ret;
+
+	ret = of_property_read_u32(np, "reg", &reg);
+	if (ret != 0 || reg >= chip->num_leds) {
+		dev_err(chip->dev, "invalid 'reg' of %pOFn\n", np);
+		return -EINVAL;
+	}
+	led->index = reg;
+
+	cdev = &led->cdev;
+	cdev->brightness_set_blocking = ktd202x_brightness_single_set;
+	cdev->blink_set = ktd202x_blink_single_set;
+
+	return devm_led_classdev_register_ext(chip->dev, &led->cdev, init_data);
+}
+
+static int ktd202x_add_led(struct ktd202x *chip, struct device_node *np, unsigned int index)
+{
+	struct ktd202x_led *led = &chip->leds[index];
+	struct led_init_data init_data = {};
+	struct led_classdev *cdev;
+	u32 color = 0;
+	int ret;
+
+	/* Color property is optional in single color case */
+	ret = of_property_read_u32(np, "color", &color);
+	if (ret < 0 && ret != -EINVAL) {
+		dev_err(chip->dev, "failed to parse 'color' of %pOF\n", np);
+		return ret;
+	}
+
+	led->chip = chip;
+	init_data.fwnode = of_fwnode_handle(np);
+
+	if (color == LED_COLOR_ID_RGB) {
+		cdev = &led->mcdev.led_cdev;
+		ret = ktd202x_setup_led_rgb(chip, np, led, &init_data);
+	} else {
+		cdev = &led->cdev;
+		ret = ktd202x_setup_led_single(chip, np, led, &init_data);
+	}
+
+	if (ret) {
+		dev_err(chip->dev, "unable to register %s\n", cdev->name);
+		of_node_put(np);
+		return ret;
+	}
+
+	cdev->max_brightness = KTD202X_MAX_BRIGHTNESS;
+
+	return 0;
+}
+
+static int ktd202x_probe_dt(struct ktd202x *chip)
+{
+	struct device_node *np = dev_of_node(chip->dev), *child;
+	unsigned int i;
+	int count, ret;
+
+	chip->num_leds = (int)(unsigned long)of_device_get_match_data(chip->dev);
+
+	count = of_get_available_child_count(np);
+	if (!count || count > chip->num_leds)
+		return -EINVAL;
+
+	regmap_write(chip->regmap, KTD202X_REG_RESET_CONTROL, KTD202X_RSTR_RESET);
+
+	/* Allow the device to execute the complete reset */
+	usleep_range(200, 300);
+
+	i = 0;
+	for_each_available_child_of_node(np, child) {
+		ret = ktd202x_add_led(chip, child, i);
+		if (ret)
+			return ret;
+		i++;
+	}
+
+	return 0;
+}
+
+static const struct regmap_config ktd202x_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0x09,
+	.cache_type = REGCACHE_FLAT,
+	.reg_defaults = ktd202x_reg_defaults,
+	.num_reg_defaults = ARRAY_SIZE(ktd202x_reg_defaults),
+};
+
+static int ktd202x_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct ktd202x *chip;
+	int count;
+	int ret;
+
+	count = device_get_child_node_count(dev);
+	if (!count || count > KTD202X_MAX_LEDS)
+		return dev_err_probe(dev, -EINVAL, "Incorrect number of leds (%d)", count);
+
+	chip = devm_kzalloc(dev, struct_size(chip, leds, count), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->dev = dev;
+	i2c_set_clientdata(client, chip);
+
+	chip->regmap = devm_regmap_init_i2c(client, &ktd202x_regmap_config);
+	if (IS_ERR(chip->regmap)) {
+		ret = dev_err_probe(dev, PTR_ERR(chip->regmap),
+				    "Failed to allocate register map.\n");
+		return ret;
+	}
+
+	chip->regulators[0].supply = "vin";
+	chip->regulators[1].supply = "vio";
+	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(chip->regulators), chip->regulators);
+	if (ret < 0) {
+		dev_err_probe(dev, ret, "Failed to request regulators.\n");
+		return ret;
+	}
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(chip->regulators), chip->regulators);
+	if (ret) {
+		dev_err_probe(dev, ret, "Failed to enable regulators.\n");
+		return ret;
+	}
+
+	ret = ktd202x_probe_dt(chip);
+	if (ret < 0) {
+		regulator_bulk_disable(ARRAY_SIZE(chip->regulators), chip->regulators);
+		return ret;
+	}
+
+	ret = regulator_bulk_disable(ARRAY_SIZE(chip->regulators), chip->regulators);
+	if (ret) {
+		dev_err_probe(dev, ret, "Failed to disable regulators.\n");
+		return ret;
+	}
+
+	mutex_init(&chip->mutex);
+
+	return 0;
+}
+
+static void ktd202x_remove(struct i2c_client *client)
+{
+	struct ktd202x *chip = i2c_get_clientdata(client);
+
+	ktd202x_chip_disable(chip);
+
+	mutex_destroy(&chip->mutex);
+}
+
+static void ktd202x_shutdown(struct i2c_client *client)
+{
+	struct ktd202x *chip = i2c_get_clientdata(client);
+
+	/* Reset registers to make sure all LEDs are off before shutdown */
+	regmap_write(chip->regmap, KTD202X_REG_RESET_CONTROL, KTD202X_RSTR_RESET);
+}
+
+static const struct of_device_id ktd202x_match_table[] = {
+	{ .compatible = "kinetic,ktd2026", .data = (void *)KTD2026_NUM_LEDS },
+	{ .compatible = "kinetic,ktd2027", .data = (void *)KTD2027_NUM_LEDS },
+	{},
+};
+MODULE_DEVICE_TABLE(of, ktd202x_match_table);
+
+static struct i2c_driver ktd202x_driver = {
+	.driver = {
+		.name = "leds-ktd202x",
+		.of_match_table = ktd202x_match_table,
+	},
+	.probe = ktd202x_probe,
+	.remove = ktd202x_remove,
+	.shutdown = ktd202x_shutdown,
+};
+module_i2c_driver(ktd202x_driver);
+
+MODULE_AUTHOR("André Apitzsch <git@apitzsch.eu>");
+MODULE_DESCRIPTION("Kinetic KTD2026/7 LED driver");
+MODULE_LICENSE("GPL");

-- 
2.42.0

Re: [PATCH v5 2/2] leds: add ktd202x driver

[Christophe JAILLET]

Le 01/10/2023 à 15:52, André Apitzsch a écrit :
> This commit adds support for Kinetic KTD2026/7 RGB/White LED driver.
> 
> Signed-off-by: André Apitzsch <git-AtRKszJ1oGPsq35pWSNszA@public.gmane.org>

...

> +static int ktd202x_setup_led_rgb(struct ktd202x *chip, struct device_node *np,
> +				 struct ktd202x_led *led, struct led_init_data *init_data)
> +{
> +	struct led_classdev *cdev;
> +	struct device_node *child;
> +	struct mc_subled *info;
> +	int num_channels;
> +	int i = 0;
> +	u32 reg;
> +	int ret;
> +
> +	num_channels = of_get_available_child_count(np);
> +	if (!num_channels || num_channels > chip->num_leds)
> +		return -EINVAL;
> +
> +	info = devm_kcalloc(chip->dev, num_channels, sizeof(*info), GFP_KERNEL);
> +	if (!info)
> +		return -ENOMEM;
> +
> +	for_each_available_child_of_node(np, child) {
> +		u32 mono_color = 0;

Un-needed init.
And, why is it defined here, while reg is defined out-side the loop?

> +
> +		ret = of_property_read_u32(child, "reg", &reg);
> +		if (ret != 0 || reg >= chip->num_leds) {
> +			dev_err(chip->dev, "invalid 'reg' of %pOFn\n", np);

Mossing of_node_put(np);?

> +			return -EINVAL;
> +		}
> +
> +		ret = of_property_read_u32(child, "color", &mono_color);
> +		if (ret < 0 && ret != -EINVAL) {
> +			dev_err(chip->dev, "failed to parse 'color' of %pOF\n", np);

Mossing of_node_put(np);?

> +			return ret;
> +		}
> +
> +		info[i].color_index = mono_color;
> +		info[i].channel = reg;
> +		info[i].intensity = KTD202X_MAX_BRIGHTNESS;
> +		i++;
> +	}
> +
> +	led->mcdev.subled_info = info;
> +	led->mcdev.num_colors = num_channels;
> +
> +	cdev = &led->mcdev.led_cdev;
> +	cdev->brightness_set_blocking = ktd202x_brightness_mc_set;
> +	cdev->blink_set = ktd202x_blink_mc_set;
> +
> +	return devm_led_classdev_multicolor_register_ext(chip->dev, &led->mcdev, init_data);
> +}
> +
> +static int ktd202x_setup_led_single(struct ktd202x *chip, struct device_node *np,
> +				    struct ktd202x_led *led, struct led_init_data *init_data)
> +{
> +	struct led_classdev *cdev;
> +	u32 reg;
> +	int ret;
> +
> +	ret = of_property_read_u32(np, "reg", &reg);
> +	if (ret != 0 || reg >= chip->num_leds) {
> +		dev_err(chip->dev, "invalid 'reg' of %pOFn\n", np);
> +		return -EINVAL;
> +	}
> +	led->index = reg;
> +
> +	cdev = &led->cdev;
> +	cdev->brightness_set_blocking = ktd202x_brightness_single_set;
> +	cdev->blink_set = ktd202x_blink_single_set;
> +
> +	return devm_led_classdev_register_ext(chip->dev, &led->cdev, init_data);
> +}
> +
> +static int ktd202x_add_led(struct ktd202x *chip, struct device_node *np, unsigned int index)
> +{
> +	struct ktd202x_led *led = &chip->leds[index];
> +	struct led_init_data init_data = {};
> +	struct led_classdev *cdev;
> +	u32 color = 0;
Un-needed init.

> +	int ret;
> +
> +	/* Color property is optional in single color case */
> +	ret = of_property_read_u32(np, "color", &color);
> +	if (ret < 0 && ret != -EINVAL) {
> +		dev_err(chip->dev, "failed to parse 'color' of %pOF\n", np);
> +		return ret;
> +	}
> +
> +	led->chip = chip;
> +	init_data.fwnode = of_fwnode_handle(np);
> +
> +	if (color == LED_COLOR_ID_RGB) {
> +		cdev = &led->mcdev.led_cdev;
> +		ret = ktd202x_setup_led_rgb(chip, np, led, &init_data);
> +	} else {
> +		cdev = &led->cdev;
> +		ret = ktd202x_setup_led_single(chip, np, led, &init_data);
> +	}
> +
> +	if (ret) {
> +		dev_err(chip->dev, "unable to register %s\n", cdev->name);
> +		of_node_put(np);

This is strange to have it here.
Why not above after "if (ret < 0 && ret != -EINVAL) {"?

It would look much more natural to have it a few lines below, ... [1]

> +		return ret;
> +	}
> +
> +	cdev->max_brightness = KTD202X_MAX_BRIGHTNESS;
> +
> +	return 0;
> +}
> +
> +static int ktd202x_probe_dt(struct ktd202x *chip)
> +{
> +	struct device_node *np = dev_of_node(chip->dev), *child;
> +	unsigned int i;
> +	int count, ret;
> +
> +	chip->num_leds = (int)(unsigned long)of_device_get_match_data(chip->dev);
> +
> +	count = of_get_available_child_count(np);
> +	if (!count || count > chip->num_leds)
> +		return -EINVAL;
> +
> +	regmap_write(chip->regmap, KTD202X_REG_RESET_CONTROL, KTD202X_RSTR_RESET);
> +
> +	/* Allow the device to execute the complete reset */
> +	usleep_range(200, 300);
> +
> +	i = 0;
> +	for_each_available_child_of_node(np, child) {
> +		ret = ktd202x_add_led(chip, child, i);
> +		if (ret)

[1] ... here.

Otherwise, it is likely that, thanks to a static checker, an additionnal 
of_node_put() will be added on early exit of the loop.

CJ

> +			return ret;
> +		i++;
> +	}
> +
> +	return 0;
> +}

...

Re: [PATCH v5 2/2] leds: add ktd202x driver

[André Apitzsch]

Hi Christophe,

Am Sonntag, dem 01.10.2023 um 17:15 +0200 schrieb Christophe JAILLET:
> Le 01/10/2023 à 15:52, André Apitzsch a écrit :
> > This commit adds support for Kinetic KTD2026/7 RGB/White LED
> > driver.
> > 
> > Signed-off-by: André Apitzsch
> > <git-AtRKszJ1oGPsq35pWSNszA@public.gmane.org>
> 
> ...
> 
> > +static int ktd202x_setup_led_rgb(struct ktd202x *chip, struct
> > device_node *np,
> > +                                struct ktd202x_led *led, struct
> > led_init_data *init_data)
> > +{
> > +       struct led_classdev *cdev;
> > +       struct device_node *child;
> > +       struct mc_subled *info;
> > +       int num_channels;
> > +       int i = 0;
> > +       u32 reg;
> > +       int ret;
> > +
> > +       num_channels = of_get_available_child_count(np);
> > +       if (!num_channels || num_channels > chip->num_leds)
> > +               return -EINVAL;
> > +
> > +       info = devm_kcalloc(chip->dev, num_channels, sizeof(*info),
> > GFP_KERNEL);
> > +       if (!info)
> > +               return -ENOMEM;
> > +
> > +       for_each_available_child_of_node(np, child) {
> > +               u32 mono_color = 0;
> 
> Un-needed init.
> And, why is it defined here, while reg is defined out-side the loop?

I'll move it out-side the loop (without initialization).

> 
> > +
> > +               ret = of_property_read_u32(child, "reg", &reg);
> > +               if (ret != 0 || reg >= chip->num_leds) {
> > +                       dev_err(chip->dev, "invalid 'reg' of
> > %pOFn\n", np);
> 
> Mossing of_node_put(np);?

It shouldn't be needed here if handled in the calling function, right? 

> 
> > +                       return -EINVAL;
> > +               }
> > +
> > +               ret = of_property_read_u32(child, "color",
> > &mono_color);
> > +               if (ret < 0 && ret != -EINVAL) {
> > +                       dev_err(chip->dev, "failed to parse 'color'
> > of %pOF\n", np);
> 
> Mossing of_node_put(np);?
> 
> > +                       return ret;
> > +               }
> > +
> > +               info[i].color_index = mono_color;
> > +               info[i].channel = reg;
> > +               info[i].intensity = KTD202X_MAX_BRIGHTNESS;
> > +               i++;
> > +       }
> > +
> > +       led->mcdev.subled_info = info;
> > +       led->mcdev.num_colors = num_channels;
> > +
> > +       cdev = &led->mcdev.led_cdev;
> > +       cdev->brightness_set_blocking = ktd202x_brightness_mc_set;
> > +       cdev->blink_set = ktd202x_blink_mc_set;
> > +
> > +       return devm_led_classdev_multicolor_register_ext(chip->dev,
> > &led->mcdev, init_data);
> > +}
> > +
> > +static int ktd202x_setup_led_single(struct ktd202x *chip, struct
> > device_node *np,
> > +                                   struct ktd202x_led *led, struct
> > led_init_data *init_data)
> > +{
> > +       struct led_classdev *cdev;
> > +       u32 reg;
> > +       int ret;
> > +
> > +       ret = of_property_read_u32(np, "reg", &reg);
> > +       if (ret != 0 || reg >= chip->num_leds) {
> > +               dev_err(chip->dev, "invalid 'reg' of %pOFn\n", np);
> > +               return -EINVAL;
> > +       }
> > +       led->index = reg;
> > +
> > +       cdev = &led->cdev;
> > +       cdev->brightness_set_blocking =
> > ktd202x_brightness_single_set;
> > +       cdev->blink_set = ktd202x_blink_single_set;
> > +
> > +       return devm_led_classdev_register_ext(chip->dev, &led-
> > >cdev, init_data);
> > +}
> > +
> > +static int ktd202x_add_led(struct ktd202x *chip, struct
> > device_node *np, unsigned int index)
> > +{
> > +       struct ktd202x_led *led = &chip->leds[index];
> > +       struct led_init_data init_data = {};
> > +       struct led_classdev *cdev;
> > +       u32 color = 0;
> Un-needed init.
> 
> > +       int ret;
> > +
> > +       /* Color property is optional in single color case */
> > +       ret = of_property_read_u32(np, "color", &color);
> > +       if (ret < 0 && ret != -EINVAL) {
> > +               dev_err(chip->dev, "failed to parse 'color' of
> > %pOF\n", np);
> > +               return ret;
> > +       }
> > +
> > +       led->chip = chip;
> > +       init_data.fwnode = of_fwnode_handle(np);
> > +
> > +       if (color == LED_COLOR_ID_RGB) {
> > +               cdev = &led->mcdev.led_cdev;
> > +               ret = ktd202x_setup_led_rgb(chip, np, led,
> > &init_data);
> > +       } else {
> > +               cdev = &led->cdev;
> > +               ret = ktd202x_setup_led_single(chip, np, led,
> > &init_data);
> > +       }
> > +
> > +       if (ret) {
> > +               dev_err(chip->dev, "unable to register %s\n", cdev-
> > >name);
> > +               of_node_put(np);
> 
> This is strange to have it here.
> Why not above after "if (ret < 0 && ret != -EINVAL) {"?
> 
> It would look much more natural to have it a few lines below, ... [1]

Good catch. I'll move of_node_put(np); to [1] and [2].

> 
> > +               return ret;
> > +       }
> > +
> > +       cdev->max_brightness = KTD202X_MAX_BRIGHTNESS;
> > +
> > +       return 0;
> > +}
> > +
> > +static int ktd202x_probe_dt(struct ktd202x *chip)
> > +{
> > +       struct device_node *np = dev_of_node(chip->dev), *child;
> > +       unsigned int i;
> > +       int count, ret;
> > +
> > +       chip->num_leds = (int)(unsigned
> > long)of_device_get_match_data(chip->dev);
> > +
> > +       count = of_get_available_child_count(np);
> > +       if (!count || count > chip->num_leds)

[2].

> > +               return -EINVAL;
> > +
> > +       regmap_write(chip->regmap, KTD202X_REG_RESET_CONTROL,
> > KTD202X_RSTR_RESET);
> > +
> > +       /* Allow the device to execute the complete reset */
> > +       usleep_range(200, 300);
> > +
> > +       i = 0;
> > +       for_each_available_child_of_node(np, child) {
> > +               ret = ktd202x_add_led(chip, child, i);
> > +               if (ret)
> 
> [1] ... here.
> 
> Otherwise, it is likely that, thanks to a static checker, an
> additionnal 
> of_node_put() will be added on early exit of the loop.
> 
> CJ
> 
> > +                       return ret;
> > +               i++;
> > +       }
> > +
> > +       return 0;
> > +}
> 
> ...
> 

Best regards,
André

Re: [PATCH v5 2/2] leds: add ktd202x driver

[Uwe Kleine-König]

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Hello André,

On Sun, Oct 01, 2023 at 06:56:20PM +0200, André Apitzsch wrote:
> Am Sonntag, dem 01.10.2023 um 17:15 +0200 schrieb Christophe JAILLET:
> > Le 01/10/2023 à 15:52, André Apitzsch a écrit :
> > > +       for_each_available_child_of_node(np, child) {
> > > +               u32 mono_color = 0;
> > 
> > Un-needed init.
> > And, why is it defined here, while reg is defined out-side the loop?
> 
> I'll move it out-side the loop (without initialization).

In my book a variable with a narrow scope is better. I didn't check, but
if you can restrict both variables to the for loop, that's nicer.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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Re: [PATCH v5 2/2] leds: add ktd202x driver

[Christophe JAILLET]

Le 01/10/2023 à 18:56, André Apitzsch a écrit :
> Hi Christophe,
> 
> Am Sonntag, dem 01.10.2023 um 17:15 +0200 schrieb Christophe JAILLET:
>> Le 01/10/2023 à 15:52, André Apitzsch a écrit :
>>> This commit adds support for Kinetic KTD2026/7 RGB/White LED
>>> driver.
>>>
>>> Signed-off-by: André Apitzsch
>>> <git-AtRKszJ1oGPsq35pWSNszA@public.gmane.org>
>>
>> ...
>>
>>> +static int ktd202x_setup_led_rgb(struct ktd202x *chip, struct
>>> device_node *np,
>>> +                                struct ktd202x_led *led, struct
>>> led_init_data *init_data)
>>> +{
>>> +       struct led_classdev *cdev;
>>> +       struct device_node *child;
>>> +       struct mc_subled *info;
>>> +       int num_channels;
>>> +       int i = 0;
>>> +       u32 reg;
>>> +       int ret;
>>> +
>>> +       num_channels = of_get_available_child_count(np);
>>> +       if (!num_channels || num_channels > chip->num_leds)
>>> +               return -EINVAL;
>>> +
>>> +       info = devm_kcalloc(chip->dev, num_channels, sizeof(*info),
>>> GFP_KERNEL);
>>> +       if (!info)
>>> +               return -ENOMEM;
>>> +
>>> +       for_each_available_child_of_node(np, child) {
>>> +               u32 mono_color = 0;
>>
>> Un-needed init.
>> And, why is it defined here, while reg is defined out-side the loop?
> 
> I'll move it out-side the loop (without initialization).
> 
>>
>>> +
>>> +               ret = of_property_read_u32(child, "reg", &reg);
>>> +               if (ret != 0 || reg >= chip->num_leds) {
>>> +                       dev_err(chip->dev, "invalid 'reg' of
>>> %pOFn\n", np);
>>
>> Mossing of_node_put(np);?
> 
> It shouldn't be needed here if handled in the calling function, right?

How can the caller do this?

The goal of this of_node_put() is to release a reference taken by the 
for_each_available_child_of_node() loop, in case of early exit.

The caller can't know if np needs to be released or not. An error code 
is returned either if an error occurs within the for_each loop, or if 
devm_led_classdev_multicolor_register_ext() fails.

More over, in your case the caller is ktd202x_add_led().
 From there either ktd202x_setup_led_rgb() or ktd202x_setup_led_single() 
is called.

ktd202x_setup_led_single() does not take any reference to np.
But if it fails, of_node_put() would still be called.

> 
>>
>>> +                       return -EINVAL;
>>> +               }
>>> +
>>> +               ret = of_property_read_u32(child, "color",
>>> &mono_color);
>>> +               if (ret < 0 && ret != -EINVAL) {
>>> +                       dev_err(chip->dev, "failed to parse 'color'
>>> of %pOF\n", np);
>>
>> Mossing of_node_put(np);?
>>
>>> +                       return ret;
>>> +               }
>>> +
>>> +               info[i].color_index = mono_color;
>>> +               info[i].channel = reg;
>>> +               info[i].intensity = KTD202X_MAX_BRIGHTNESS;
>>> +               i++;
>>> +       }
>>> +
>>> +       led->mcdev.subled_info = info;
>>> +       led->mcdev.num_colors = num_channels;
>>> +
>>> +       cdev = &led->mcdev.led_cdev;
>>> +       cdev->brightness_set_blocking = ktd202x_brightness_mc_set;
>>> +       cdev->blink_set = ktd202x_blink_mc_set;
>>> +
>>> +       return devm_led_classdev_multicolor_register_ext(chip->dev,
>>> &led->mcdev, init_data);
>>> +}
>>> +
>>> +static int ktd202x_setup_led_single(struct ktd202x *chip, struct
>>> device_node *np,
>>> +                                   struct ktd202x_led *led, struct
>>> led_init_data *init_data)
>>> +{
>>> +       struct led_classdev *cdev;
>>> +       u32 reg;
>>> +       int ret;
>>> +
>>> +       ret = of_property_read_u32(np, "reg", &reg);
>>> +       if (ret != 0 || reg >= chip->num_leds) {
>>> +               dev_err(chip->dev, "invalid 'reg' of %pOFn\n", np);
>>> +               return -EINVAL;
>>> +       }
>>> +       led->index = reg;
>>> +
>>> +       cdev = &led->cdev;
>>> +       cdev->brightness_set_blocking =
>>> ktd202x_brightness_single_set;
>>> +       cdev->blink_set = ktd202x_blink_single_set;
>>> +
>>> +       return devm_led_classdev_register_ext(chip->dev, &led-
>>>> cdev, init_data);
>>> +}
>>> +
>>> +static int ktd202x_add_led(struct ktd202x *chip, struct
>>> device_node *np, unsigned int index)
>>> +{
>>> +       struct ktd202x_led *led = &chip->leds[index];
>>> +       struct led_init_data init_data = {};
>>> +       struct led_classdev *cdev;
>>> +       u32 color = 0;
>> Un-needed init.
>>
>>> +       int ret;
>>> +
>>> +       /* Color property is optional in single color case */
>>> +       ret = of_property_read_u32(np, "color", &color);
>>> +       if (ret < 0 && ret != -EINVAL) {
>>> +               dev_err(chip->dev, "failed to parse 'color' of
>>> %pOF\n", np);
>>> +               return ret;
>>> +       }
>>> +
>>> +       led->chip = chip;
>>> +       init_data.fwnode = of_fwnode_handle(np);
>>> +
>>> +       if (color == LED_COLOR_ID_RGB) {
>>> +               cdev = &led->mcdev.led_cdev;
>>> +               ret = ktd202x_setup_led_rgb(chip, np, led,
>>> &init_data);
>>> +       } else {
>>> +               cdev = &led->cdev;
>>> +               ret = ktd202x_setup_led_single(chip, np, led,
>>> &init_data);
>>> +       }
>>> +
>>> +       if (ret) {
>>> +               dev_err(chip->dev, "unable to register %s\n", cdev-
>>>> name);
>>> +               of_node_put(np);
>>
>> This is strange to have it here.
>> Why not above after "if (ret < 0 && ret != -EINVAL) {"?
>>
>> It would look much more natural to have it a few lines below, ... [1]
> 
> Good catch. I'll move of_node_put(np); to [1] and [2].

Why [2]?
It does not seem needed here.

of_get_available_child_count() does not keep any reference.

CJ

> 
>>
>>> +               return ret;
>>> +       }
>>> +
>>> +       cdev->max_brightness = KTD202X_MAX_BRIGHTNESS;
>>> +
>>> +       return 0;
>>> +}
>>> +
>>> +static int ktd202x_probe_dt(struct ktd202x *chip)
>>> +{
>>> +       struct device_node *np = dev_of_node(chip->dev), *child;
>>> +       unsigned int i;
>>> +       int count, ret;
>>> +
>>> +       chip->num_leds = (int)(unsigned
>>> long)of_device_get_match_data(chip->dev);
>>> +
>>> +       count = of_get_available_child_count(np);
>>> +       if (!count || count > chip->num_leds)
> 
> [2].
> 
>>> +               return -EINVAL;
>>> +
>>> +       regmap_write(chip->regmap, KTD202X_REG_RESET_CONTROL,
>>> KTD202X_RSTR_RESET);
>>> +
>>> +       /* Allow the device to execute the complete reset */
>>> +       usleep_range(200, 300);
>>> +
>>> +       i = 0;
>>> +       for_each_available_child_of_node(np, child) {
>>> +               ret = ktd202x_add_led(chip, child, i);
>>> +               if (ret)
>>
>> [1] ... here.
>>
>> Otherwise, it is likely that, thanks to a static checker, an
>> additionnal
>> of_node_put() will be added on early exit of the loop.
>>
>> CJ
>>
>>> +                       return ret;
>>> +               i++;
>>> +       }
>>> +
>>> +       return 0;
>>> +}
>>
>> ...
>>
> 
> Best regards,
> André
> 

Re: [PATCH v5 2/2] leds: add ktd202x driver

[André Apitzsch]

Am Sonntag, dem 01.10.2023 um 22:46 +0200 schrieb Christophe JAILLET:
> Le 01/10/2023 à 18:56, André Apitzsch a écrit :
> > Hi Christophe,
> > 
> > Am Sonntag, dem 01.10.2023 um 17:15 +0200 schrieb Christophe
> > JAILLET:
> > > Le 01/10/2023 à 15:52, André Apitzsch a écrit :
> > > > This commit adds support for Kinetic KTD2026/7 RGB/White LED
> > > > driver.
> > > > 
> > > > Signed-off-by: André Apitzsch
> > > > <git-AtRKszJ1oGPsq35pWSNszA@public.gmane.org>
> > > 
> > > ...
> > > 
> > > > +static int ktd202x_setup_led_rgb(struct ktd202x *chip, struct
> > > > device_node *np,
> > > > +                                struct ktd202x_led *led,
> > > > struct
> > > > led_init_data *init_data)
> > > > +{
> > > > +       struct led_classdev *cdev;
> > > > +       struct device_node *child;
> > > > +       struct mc_subled *info;
> > > > +       int num_channels;
> > > > +       int i = 0;
> > > > +       u32 reg;
> > > > +       int ret;
> > > > +
> > > > +       num_channels = of_get_available_child_count(np);
> > > > +       if (!num_channels || num_channels > chip->num_leds)
> > > > +               return -EINVAL;
> > > > +
> > > > +       info = devm_kcalloc(chip->dev, num_channels,
> > > > sizeof(*info),
> > > > GFP_KERNEL);
> > > > +       if (!info)
> > > > +               return -ENOMEM;
> > > > +
> > > > +       for_each_available_child_of_node(np, child) {
> > > > +               u32 mono_color = 0;
> > > 
> > > Un-needed init.
> > > And, why is it defined here, while reg is defined out-side the
> > > loop?
> > 
> > I'll move it out-side the loop (without initialization).
> > 
> > > 
> > > > +
> > > > +               ret = of_property_read_u32(child, "reg", &reg);
> > > > +               if (ret != 0 || reg >= chip->num_leds) {
> > > > +                       dev_err(chip->dev, "invalid 'reg' of
> > > > %pOFn\n", np);
> > > 
> > > Mossing of_node_put(np);?
> > 
> > It shouldn't be needed here if handled in the calling function,
> > right?
> 
> How can the caller do this?
> 
> The goal of this of_node_put() is to release a reference taken by the
> for_each_available_child_of_node() loop, in case of early exit.
> 
> The caller can't know if np needs to be released or not. An error
> code 
> is returned either if an error occurs within the for_each loop, or if
> devm_led_classdev_multicolor_register_ext() fails.
> 
> More over, in your case the caller is ktd202x_add_led().
>  From there either ktd202x_setup_led_rgb() or
> ktd202x_setup_led_single() 
> is called.
> 
> ktd202x_setup_led_single() does not take any reference to np.
> But if it fails, of_node_put() would still be called.
> 
> 

Hello Christophe,

It seems I misunderstood when of_node_put() is used. Thanks for the
explanation.

While checking the usage of of_node_put(), I noticed that dev_err()
(and of_node_put()) should take "child" and not "np", here.

André

> > > 
> > > > +                       return -EINVAL;
> > > > +               }
> > > > +
> > > > +               ret = of_property_read_u32(child, "color",
> > > > &mono_color);
> > > > +               if (ret < 0 && ret != -EINVAL) {
> > > > +                       dev_err(chip->dev, "failed to parse
> > > > 'color'
> > > > of %pOF\n", np);
> > > 
> > > Mossing of_node_put(np);?
> > > 
> > > > +                       return ret;
> > > > +               }
> > > > +
> > > > +               info[i].color_index = mono_color;
> > > > +               info[i].channel = reg;
> > > > +               info[i].intensity = KTD202X_MAX_BRIGHTNESS;
> > > > +               i++;
> > > > +       }
> > > > +
> > > > +       led->mcdev.subled_info = info;
> > > > +       led->mcdev.num_colors = num_channels;
> > > > +
> > > > +       cdev = &led->mcdev.led_cdev;
> > > > +       cdev->brightness_set_blocking =
> > > > ktd202x_brightness_mc_set;
> > > > +       cdev->blink_set = ktd202x_blink_mc_set;
> > > > +
> > > > +       return devm_led_classdev_multicolor_register_ext(chip-
> > > > >dev,
> > > > &led->mcdev, init_data);
> > > > +}
> > > > +
> > > > +static int ktd202x_setup_led_single(struct ktd202x *chip,
> > > > struct
> > > > device_node *np,
> > > > +                                   struct ktd202x_led *led,
> > > > struct
> > > > led_init_data *init_data)
> > > > +{
> > > > +       struct led_classdev *cdev;
> > > > +       u32 reg;
> > > > +       int ret;
> > > > +
> > > > +       ret = of_property_read_u32(np, "reg", &reg);
> > > > +       if (ret != 0 || reg >= chip->num_leds) {
> > > > +               dev_err(chip->dev, "invalid 'reg' of %pOFn\n",
> > > > np);
> > > > +               return -EINVAL;
> > > > +       }
> > > > +       led->index = reg;
> > > > +
> > > > +       cdev = &led->cdev;
> > > > +       cdev->brightness_set_blocking =
> > > > ktd202x_brightness_single_set;
> > > > +       cdev->blink_set = ktd202x_blink_single_set;
> > > > +
> > > > +       return devm_led_classdev_register_ext(chip->dev, &led-
> > > > > cdev, init_data);
> > > > +}
> > > > +
> > > > +static int ktd202x_add_led(struct ktd202x *chip, struct
> > > > device_node *np, unsigned int index)
> > > > +{
> > > > +       struct ktd202x_led *led = &chip->leds[index];
> > > > +       struct led_init_data init_data = {};
> > > > +       struct led_classdev *cdev;
> > > > +       u32 color = 0;
> > > Un-needed init.
> > > 
> > > > +       int ret;
> > > > +
> > > > +       /* Color property is optional in single color case */
> > > > +       ret = of_property_read_u32(np, "color", &color);
> > > > +       if (ret < 0 && ret != -EINVAL) {
> > > > +               dev_err(chip->dev, "failed to parse 'color' of
> > > > %pOF\n", np);
> > > > +               return ret;
> > > > +       }
> > > > +
> > > > +       led->chip = chip;
> > > > +       init_data.fwnode = of_fwnode_handle(np);
> > > > +
> > > > +       if (color == LED_COLOR_ID_RGB) {
> > > > +               cdev = &led->mcdev.led_cdev;
> > > > +               ret = ktd202x_setup_led_rgb(chip, np, led,
> > > > &init_data);
> > > > +       } else {
> > > > +               cdev = &led->cdev;
> > > > +               ret = ktd202x_setup_led_single(chip, np, led,
> > > > &init_data);
> > > > +       }
> > > > +
> > > > +       if (ret) {
> > > > +               dev_err(chip->dev, "unable to register %s\n",
> > > > cdev-
> > > > > name);
> > > > +               of_node_put(np);
> > > 
> > > This is strange to have it here.
> > > Why not above after "if (ret < 0 && ret != -EINVAL) {"?
> > > 
> > > It would look much more natural to have it a few lines below, ...
> > > [1]
> > 
> > Good catch. I'll move of_node_put(np); to [1] and [2].
> 
> Why [2]?
> It does not seem needed here.
> 
> of_get_available_child_count() does not keep any reference.
> 
> CJ
> 
> > 
> > > 
> > > > +               return ret;
> > > > +       }
> > > > +
> > > > +       cdev->max_brightness = KTD202X_MAX_BRIGHTNESS;
> > > > +
> > > > +       return 0;
> > > > +}
> > > > +
> > > > +static int ktd202x_probe_dt(struct ktd202x *chip)
> > > > +{
> > > > +       struct device_node *np = dev_of_node(chip->dev),
> > > > *child;
> > > > +       unsigned int i;
> > > > +       int count, ret;
> > > > +
> > > > +       chip->num_leds = (int)(unsigned
> > > > long)of_device_get_match_data(chip->dev);
> > > > +
> > > > +       count = of_get_available_child_count(np);
> > > > +       if (!count || count > chip->num_leds)
> > 
> > [2].
> > 
> > > > +               return -EINVAL;
> > > > +
> > > > +       regmap_write(chip->regmap, KTD202X_REG_RESET_CONTROL,
> > > > KTD202X_RSTR_RESET);
> > > > +
> > > > +       /* Allow the device to execute the complete reset */
> > > > +       usleep_range(200, 300);
> > > > +
> > > > +       i = 0;
> > > > +       for_each_available_child_of_node(np, child) {
> > > > +               ret = ktd202x_add_led(chip, child, i);
> > > > +               if (ret)
> > > 
> > > [1] ... here.
> > > 
> > > Otherwise, it is likely that, thanks to a static checker, an
> > > additionnal
> > > of_node_put() will be added on early exit of the loop.
> > > 
> > > CJ
> > > 
> > > > +                       return ret;
> > > > +               i++;
> > > > +       }
> > > > +
> > > > +       return 0;
> > > > +}
> > > 
> > > ...
> > > 
> > 
> > Best regards,
> > André
> > 
>