[PATCH v4 0/2] leds: add ktd20xx LED driver support

[PATCH v4 0/2] leds: add ktd20xx LED driver support

[Florian Eckert]

v1: Initial send
v2: Remove variant 1 from source
v3: Changes requested by Andy Shevchenko added. Thanks for reviewing
  - Removing OF dependency
  - Add missing includes
  - Use device_property_read_u32() instead of fwnode_property_read_u32()
  - Use one liner function pattern <test> ? <value-true> : <value-false>
  - Remove switch case call for intensity color selection use BIT()
    instead
  - Remove not needed fwnode_handle_put() in ktd200xx_probe_dt()
    function
  - Use dev_get_drvdata() instead of i2c_get_clientdata() function call
  - Use sysfs_emit() function call
  - Use kstrtobool() function call
  - Remove not needed comma after last array element
  - Use dev_err_probe() instead of dev_error() in driver probe function
  - Do not use dev_group registration function set .dev_groups directly
    into ktd20xx_driver struct.
v4: Changes requested by Andy Shevchenko. Thanks again for your review
  - Fix Author indentation
  - Reduce logging noise
  - Use 'if' standard pattern
  - Use set_bit function to make code cleaner
  - Use meaningful jump labels
  - Updating the logging output to better match the source code
  - Remove duplicate dev pointer usage. This is not necessary as the
    information can be used directly from the client structure
  - Do not hide return value from kstrbool function
  - Do not use mutex_destroy function in devm mananged structs

Florian Eckert (2):
  leds: ktd20xx: Extension of the KTD20xx family of LED drivers from
    Kinetic
  dt: bindings: KTD20xx: Introduce the ktd20xx family of RGB drivers

 .../bindings/leds/leds-ktd20xx.yaml           | 130 ++++
 MAINTAINERS                                   |   7 +
 drivers/leds/Kconfig                          |  12 +
 drivers/leds/Makefile                         |   1 +
 drivers/leds/leds-ktd20xx.c                   | 582 ++++++++++++++++++
 5 files changed, 732 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/leds-ktd20xx.yaml
 create mode 100644 drivers/leds/leds-ktd20xx.c

-- 
2.20.1

[PATCH v4 1/2] leds: ktd20xx: Extension of the KTD20xx family of LED drivers from Kinetic

[Florian Eckert]

Introducing the KTD2061/58/59/60 RGB LED drivers. The difference in
these are the address numbers on the I2C bus that the device listens to.

All KT20xx units can drive up to 12 LEDs.

Due to the hardware limitation, we can only set 7 colors and the color
black (LED off) for each LED independently and not the full RGB range.
This is because the chip only has two color registers.

To control the LEDs independently, the chip has to be configured in a
special way.

Color register 0 must be loaded with the current value 0mA, and color
register 1 must be loaded with the value 'kinetic,led-current' from the
device tree node. If the property is omitted, the register is loaded
with the default value (0x28 = 5mA).

To select a color for an LED, a combination must be written to the color
selection register of that LED. This range for selecting the value is 3
bits wide (RGB). A '0' in any of the bits uses color register '0' and a
'1' uses color register '1'.

So we could choose the following combination for each LED:
R G B
0 0 0 = Black (off)
0 0 1 = Blue
0 1 0 = green
0 1 1 = Cyan
1 0 0 = Red
1 0 1 = Magenta
1 1 0 = Yellow
1 1 1 = White

Signed-off-by: Florian Eckert <fe@dev.tdt.de>
---
 MAINTAINERS                 |   6 +
 drivers/leds/Kconfig        |  12 +
 drivers/leds/Makefile       |   1 +
 drivers/leds/leds-ktd20xx.c | 582 ++++++++++++++++++++++++++++++++++++
 4 files changed, 601 insertions(+)
 create mode 100644 drivers/leds/leds-ktd20xx.c

diff --git a/MAINTAINERS b/MAINTAINERS
index a58544f7b699..04d68985d348 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10739,6 +10739,12 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/leds/backlight/kinetic,ktd253.yaml
 F:	drivers/video/backlight/ktd253-backlight.c
 
+KTD20XX LED CONTROLLER DRIVER
+M:	Florian Eckert <fe@dev.tdt.de>
+L:	linux-leds@vger.kernel.org
+S:	Maintained
+F:	drivers/leds/leds-ktd20xx.c
+
 KTEST
 M:	Steven Rostedt <rostedt@goodmis.org>
 M:	John Hawley <warthog9@eaglescrag.net>
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 6090e647daee..a96e6bf7918b 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -157,6 +157,18 @@ config LEDS_EL15203000
 	  To compile this driver as a module, choose M here: the module
 	  will be called leds-el15203000.
 
+config LEDS_KTD20XX
+	tristate "LED Support for KTD2061/58/59/60 LED driver chip"
+	depends on LEDS_CLASS && I2C
+	depends on LEDS_CLASS_MULTICOLOR
+	select REGMAP_I2C
+	help
+	  If you say yes here you get support for the Kinetic
+	  KTD2061, KTD2058, KTD2059 and KTD2060 LED driver.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called leds-ktd20xx.
+
 config LEDS_TURRIS_OMNIA
 	tristate "LED support for CZ.NIC's Turris Omnia"
 	depends on LEDS_CLASS_MULTICOLOR
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index e58ecb36360f..5a86e72ea722 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -34,6 +34,7 @@ obj-$(CONFIG_LEDS_IP30)			+= leds-ip30.o
 obj-$(CONFIG_LEDS_IPAQ_MICRO)		+= leds-ipaq-micro.o
 obj-$(CONFIG_LEDS_IS31FL319X)		+= leds-is31fl319x.o
 obj-$(CONFIG_LEDS_IS31FL32XX)		+= leds-is31fl32xx.o
+obj-${CONFIG_LEDS_KTD20XX}		+= leds-ktd20xx.o
 obj-$(CONFIG_LEDS_LM3530)		+= leds-lm3530.o
 obj-$(CONFIG_LEDS_LM3532)		+= leds-lm3532.o
 obj-$(CONFIG_LEDS_LM3533)		+= leds-lm3533.o
diff --git a/drivers/leds/leds-ktd20xx.c b/drivers/leds/leds-ktd20xx.c
new file mode 100644
index 000000000000..7e2a1a603b50
--- /dev/null
+++ b/drivers/leds/leds-ktd20xx.c
@@ -0,0 +1,582 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  LEDs driver for the Kinetic KDT20xx device
+ *
+ *  Copyright (C) 2021 TDT AG Florian Eckert <fe@dev.tdt.de>
+ *
+ */
+
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/leds.h>
+#include <linux/led-class-multicolor.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+
+/* I2C Register Map */
+#define KTD20XX_ID		0x00
+#define KTD20XX_MONITOR		0x01
+#define KTD20XX_CONTROL		0x02
+
+/* Color0 Configuration Registers */
+#define KTD20XX_IRED0		0x03
+#define KTD20XX_IGRN0		0x04
+#define KTD20XX_IBLU0		0x05
+
+/* Color1 Configuration Registers */
+#define KTD20XX_IRED1		0x06
+#define KTD20XX_IGRN1		0x07
+#define KTD20XX_IBLU1		0x08
+
+/* Selection Configuration Register */
+#define KTD20XX_ISELA12		0x09
+#define KTD20XX_ISELA34		0x0A
+#define KTD20XX_ISELB12		0x0B
+#define KTD20XX_ISELB34		0x0C
+#define KTD20XX_ISELC12		0x0D
+#define KTD20XX_ISELC34		0x0E
+
+#define KTD20XX_MAX_LEDS	12
+#define KTD20XX_LED_CHANNELS	3
+
+enum ktd20xx_led_number {
+	/* ISELA12 */
+	RGB_A1,
+	RGB_A2,
+	/* ISELA34 */
+	RGB_A3,
+	RGB_A4,
+	/* ISELB12 */
+	RGB_B1,
+	RGB_B2,
+	/* ISELB34 */
+	RGB_B3,
+	RGB_B4,
+	/* ISELC12 */
+	RGB_C1,
+	RGB_C2,
+	/* ISELC34 */
+	RGB_C3,
+	RGB_C4,
+};
+
+enum ktd20xx_control_mode {
+	CONTROL_MODE_OFF,
+	CONTROL_MODE_NIGHT,
+	CONTROL_MODE_NORMAL,
+	CONTROL_MODE_RESET,
+};
+
+static const struct reg_default ktd20xx_reg_defs[] = {
+	/* Color0 Configuration Registers */
+	{KTD20XX_IRED0, 0x28},
+	{KTD20XX_IGRN0, 0x28},
+	{KTD20XX_IBLU0, 0x28},
+	/* Color1 Configuration Registers */
+	{KTD20XX_IRED1, 0x60},
+	{KTD20XX_IGRN1, 0x60},
+	{KTD20XX_IBLU1, 0x60},
+	/* Selection Configuration Register */
+	{KTD20XX_ISELA12, 0x00},
+	{KTD20XX_ISELA34, 0x00},
+	{KTD20XX_ISELB12, 0x00},
+	{KTD20XX_ISELB34, 0x00},
+	{KTD20XX_ISELC12, 0x00},
+	{KTD20XX_ISELC34, 0x00}
+};
+
+/* Chip values */
+static const struct reg_field kt20xx_control_mode = REG_FIELD(KTD20XX_CONTROL, 6, 7);
+static const struct reg_field kt20xx_faderate = REG_FIELD(KTD20XX_CONTROL, 0, 2);
+static const struct reg_field kt20xx_vendor = REG_FIELD(KTD20XX_ID, 5, 7);
+static const struct reg_field kt20xx_chip_id = REG_FIELD(KTD20XX_ID, 0, 4);
+static const struct reg_field kt20xx_chip_rev = REG_FIELD(KTD20XX_MONITOR, 4, 7);
+
+/* ISELA1 and ISELA2 */
+static const struct reg_field kt20xx_a1_select = REG_FIELD(KTD20XX_ISELA12, 4, 6);
+static const struct reg_field kt20xx_a1_enable = REG_FIELD(KTD20XX_ISELA12, 7, 7);
+static const struct reg_field kt20xx_a2_select = REG_FIELD(KTD20XX_ISELA12, 0, 2);
+static const struct reg_field kt20xx_a2_enable = REG_FIELD(KTD20XX_ISELA12, 3, 3);
+
+/* ISELA3 and ISELA4 */
+static const struct reg_field kt20xx_a3_select = REG_FIELD(KTD20XX_ISELA34, 4, 6);
+static const struct reg_field kt20xx_a3_enable = REG_FIELD(KTD20XX_ISELA34, 7, 7);
+static const struct reg_field kt20xx_a4_select = REG_FIELD(KTD20XX_ISELA34, 0, 2);
+static const struct reg_field kt20xx_a4_enable = REG_FIELD(KTD20XX_ISELA34, 3, 3);
+
+/* ISELB1 and ISELB2 */
+static const struct reg_field kt20xx_b1_select = REG_FIELD(KTD20XX_ISELB12, 4, 6);
+static const struct reg_field kt20xx_b1_enable = REG_FIELD(KTD20XX_ISELB12, 7, 7);
+static const struct reg_field kt20xx_b2_select = REG_FIELD(KTD20XX_ISELB12, 0, 2);
+static const struct reg_field kt20xx_b2_enable = REG_FIELD(KTD20XX_ISELB12, 3, 3);
+
+/* ISELB3 and ISELB4 */
+static const struct reg_field kt20xx_b3_select = REG_FIELD(KTD20XX_ISELB34, 4, 6);
+static const struct reg_field kt20xx_b3_enable = REG_FIELD(KTD20XX_ISELB34, 7, 7);
+static const struct reg_field kt20xx_b4_select = REG_FIELD(KTD20XX_ISELB34, 0, 2);
+static const struct reg_field kt20xx_b4_enable = REG_FIELD(KTD20XX_ISELB34, 3, 3);
+
+/* ISELC1 and ISELC2 */
+static const struct reg_field kt20xx_c1_select = REG_FIELD(KTD20XX_ISELC12, 4, 6);
+static const struct reg_field kt20xx_c1_enable = REG_FIELD(KTD20XX_ISELC12, 7, 7);
+static const struct reg_field kt20xx_c2_select = REG_FIELD(KTD20XX_ISELC12, 0, 2);
+static const struct reg_field kt20xx_c2_enable = REG_FIELD(KTD20XX_ISELC12, 3, 3);
+
+/* ISELC3 and ISELC4 */
+static const struct reg_field kt20xx_c3_select = REG_FIELD(KTD20XX_ISELC34, 4, 6);
+static const struct reg_field kt20xx_c3_enable = REG_FIELD(KTD20XX_ISELC34, 7, 7);
+static const struct reg_field kt20xx_c4_select = REG_FIELD(KTD20XX_ISELC34, 0, 2);
+static const struct reg_field kt20xx_c4_enable = REG_FIELD(KTD20XX_ISELC34, 3, 3);
+
+static const struct regmap_range ktd20xx_volatile_ranges = {
+	.range_min = KTD20XX_ID,
+	.range_max = KTD20XX_CONTROL,
+};
+
+static const struct regmap_access_table ktd20xx_volatile_table = {
+	.yes_ranges = &ktd20xx_volatile_ranges,
+	.n_yes_ranges = 1,
+};
+
+static const struct regmap_range ktd20xx_readable_ranges = {
+	.range_min = KTD20XX_ID,
+	.range_max = KTD20XX_MONITOR,
+};
+
+static const struct regmap_access_table ktd20xx_readable_table = {
+	.yes_ranges = &ktd20xx_readable_ranges,
+	.n_yes_ranges = 1,
+};
+
+static const struct regmap_config ktd20xx_regmap_config = {
+	.name = "ktd20xx_regmap",
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.max_register = KTD20XX_ISELC34,
+
+	.volatile_table = &ktd20xx_volatile_table,
+	.rd_table = &ktd20xx_readable_table,
+
+	.reg_defaults = ktd20xx_reg_defs,
+	.num_reg_defaults = ARRAY_SIZE(ktd20xx_reg_defs),
+	.cache_type = REGCACHE_FLAT,
+};
+
+struct ktd20xx_led {
+	struct led_classdev_mc mc_cdev;
+	struct mc_subled subled_info[KTD20XX_LED_CHANNELS];
+	int index;
+	struct regmap_field *enable;
+	struct regmap_field *select;
+	struct ktd20xx *chip;
+};
+
+struct ktd20xx {
+	struct mutex lock;
+	struct i2c_client *client;
+	struct regmap *regmap;
+	struct regmap_field *control_mode;
+	struct regmap_field *faderate;
+	struct regmap_field *vendor;
+	struct regmap_field *chip_id;
+	struct regmap_field *chip_rev;
+	struct ktd20xx_led leds[KTD20XX_MAX_LEDS];
+};
+
+static int ktd20xx_hwinit(struct ktd20xx *chip)
+{
+	struct device *dev = &chip->client->dev;
+	int ret;
+	unsigned int value;
+
+	/*
+	 * If the device tree property 'kinetc,led-current' is found
+	 * then set this value into the color0 register as the max current
+	 * for all color channel LEDs. If this poperty is not set then
+	 * use the default value 0x28 set by the chip after a hardware reset.
+	 * The hardware default value 0x28 corresponds to 5mA.
+	 */
+	/* Set color1 register current value to 0x00 and therefor 0mA */
+	regmap_write(chip->regmap, KTD20XX_IRED1, 0);
+	regmap_write(chip->regmap, KTD20XX_IGRN1, 0);
+	regmap_write(chip->regmap, KTD20XX_IBLU1, 0);
+
+	ret = device_property_read_u32(dev, "kinetic,led-current", &value);
+	if (ret) {
+		dev_warn(dev, "property 'kinetic,led-current' not found. Using default hardware value 0x28 (5mA).\n");
+	} else {
+		dev_dbg(dev, "property 'kinetic,led-current' found. Using value 0x%02x.\n",
+				value);
+		regmap_write(chip->regmap, KTD20XX_IRED0, value);
+		regmap_write(chip->regmap, KTD20XX_IGRN0, value);
+		regmap_write(chip->regmap, KTD20XX_IBLU0, value);
+	}
+
+	/* Enable chip to run in 'normal mode' */
+	regmap_field_write(chip->control_mode, CONTROL_MODE_NORMAL);
+
+	return 0;
+}
+
+static struct ktd20xx_led *mcled_cdev_to_led(struct led_classdev_mc *mc_cdev)
+{
+	return container_of(mc_cdev, struct ktd20xx_led, mc_cdev);
+}
+
+static int ktd20xx_brightness_set(struct led_classdev *cdev,
+		enum led_brightness brightness)
+{
+	struct led_classdev_mc *mc_dev = lcdev_to_mccdev(cdev);
+	struct ktd20xx_led *led = mcled_cdev_to_led(mc_dev);
+	struct device *dev = &led->chip->client->dev;
+	int ret;
+	int i;
+	unsigned long rgb = 0;
+
+	mutex_lock(&led->chip->lock);
+	ret = regmap_field_write(led->enable, brightness ? 1 : 0);
+	if (ret) {
+		dev_err(dev, "Cannot set enable flag of LED %d error: %d\n",
+				led->index, ret);
+		goto unlock_out;
+	}
+
+	for (i = 0; i < led->mc_cdev.num_colors; i++) {
+		unsigned int intensity = mc_dev->subled_info[i].intensity;
+		unsigned int channel = mc_dev->subled_info[i].channel;
+
+		if (intensity > 0)
+			set_bit(channel, &rgb);
+	}
+
+	/*
+	 * To use the color0 registers default value after an hadware reset,
+	 * if the device tree property 'kinetc,led-current' is not set,
+	 * we have to 'invert' the rgb channel!
+	 */
+	ret = regmap_field_write(led->select, ~rgb);
+	if (ret) {
+		dev_err(dev, "Can not set RGB for LED %d error: %d\n",
+				led->index, ret);
+		goto unlock_out;
+	}
+
+unlock_out:
+	mutex_unlock(&led->chip->lock);
+	return ret;
+}
+
+static int ktd20xx_probe_dt(struct ktd20xx *chip)
+{
+	struct fwnode_handle *child = NULL;
+	struct led_init_data init_data = {};
+	struct led_classdev *led_cdev;
+	struct ktd20xx_led *led;
+	struct device *dev = &chip->client->dev;
+	int color;
+	int ret;
+	int i = 0;
+
+	device_for_each_child_node(dev, child) {
+		led = &chip->leds[i];
+
+		ret = fwnode_property_read_u32(child, "reg", &led->index);
+		if (ret) {
+			dev_err(dev, "missing property 'reg'\n");
+			goto child_out;
+		}
+		if (led->index >= KTD20XX_MAX_LEDS) {
+			dev_warn(dev, "property 'reg' is greater then '%i'\n",
+					KTD20XX_MAX_LEDS);
+			ret = -EINVAL;
+			goto child_out;
+		}
+
+		ret = fwnode_property_read_u32(child, "color", &color);
+		if (ret) {
+			dev_err(dev, "missing property 'color'\n");
+			goto child_out;
+		}
+		if (color != LED_COLOR_ID_MULTI) {
+			dev_warn(dev, "property 'color' is not equal to the value 'LED_COLOR_ID_MULTI'\n");
+			ret = -EINVAL;
+			goto child_out;
+		}
+
+		led->subled_info[0].color_index = LED_COLOR_ID_RED;
+		led->subled_info[0].channel = 2;
+		led->subled_info[0].intensity = 1;
+		led->subled_info[1].color_index = LED_COLOR_ID_GREEN;
+		led->subled_info[1].channel = 1;
+		led->subled_info[1].intensity = 1;
+		led->subled_info[2].color_index = LED_COLOR_ID_BLUE;
+		led->subled_info[2].channel = 0;
+		led->subled_info[2].intensity = 1;
+
+		led->mc_cdev.subled_info = led->subled_info;
+		led->mc_cdev.num_colors = KTD20XX_LED_CHANNELS;
+
+		init_data.fwnode = child;
+
+		led->chip = chip;
+		led_cdev = &led->mc_cdev.led_cdev;
+		led_cdev->brightness_set_blocking = ktd20xx_brightness_set;
+
+		switch (led->index) {
+		case RGB_A1:
+			led->select = devm_regmap_field_alloc(dev,
+					chip->regmap, kt20xx_a1_select);
+			led->enable = devm_regmap_field_alloc(dev,
+					chip->regmap, kt20xx_a1_enable);
+			break;
+		case RGB_A2:
+			led->select = devm_regmap_field_alloc(dev,
+					chip->regmap, kt20xx_a2_select);
+			led->enable = devm_regmap_field_alloc(dev,
+					chip->regmap, kt20xx_a2_enable);
+			break;
+		case RGB_A3:
+			led->select = devm_regmap_field_alloc(dev,
+					chip->regmap, kt20xx_a3_select);
+			led->enable = devm_regmap_field_alloc(dev,
+					chip->regmap, kt20xx_a3_enable);
+			break;
+		case RGB_A4:
+			led->select = devm_regmap_field_alloc(dev,
+					chip->regmap, kt20xx_a4_select);
+			led->enable = devm_regmap_field_alloc(dev,
+					chip->regmap, kt20xx_a4_enable);
+			break;
+		case RGB_B1:
+			led->select = devm_regmap_field_alloc(dev,
+					chip->regmap, kt20xx_b1_select);
+			led->enable = devm_regmap_field_alloc(dev,
+					chip->regmap, kt20xx_b1_enable);
+			break;
+		case RGB_B2:
+			led->select = devm_regmap_field_alloc(dev,
+					chip->regmap, kt20xx_b2_select);
+			led->enable = devm_regmap_field_alloc(dev,
+					chip->regmap, kt20xx_b2_enable);
+			break;
+		case RGB_B3:
+			led->select = devm_regmap_field_alloc(dev,
+					chip->regmap, kt20xx_b3_select);
+			led->enable = devm_regmap_field_alloc(dev,
+					chip->regmap, kt20xx_b3_enable);
+			break;
+		case RGB_B4:
+			led->select = devm_regmap_field_alloc(dev,
+					chip->regmap, kt20xx_b4_select);
+			led->enable = devm_regmap_field_alloc(dev,
+					chip->regmap, kt20xx_b4_enable);
+			break;
+		case RGB_C1:
+			led->select = devm_regmap_field_alloc(dev,
+					chip->regmap, kt20xx_c1_select);
+			led->enable = devm_regmap_field_alloc(dev,
+					chip->regmap, kt20xx_c1_enable);
+			break;
+		case RGB_C2:
+			led->select = devm_regmap_field_alloc(dev,
+					chip->regmap, kt20xx_c2_select);
+			led->enable = devm_regmap_field_alloc(dev,
+					chip->regmap, kt20xx_c2_enable);
+			break;
+		case RGB_C3:
+			led->select = devm_regmap_field_alloc(dev,
+					chip->regmap, kt20xx_c3_select);
+			led->enable = devm_regmap_field_alloc(dev,
+					chip->regmap, kt20xx_c3_enable);
+			break;
+		case RGB_C4:
+			led->select = devm_regmap_field_alloc(dev,
+					chip->regmap, kt20xx_c4_select);
+			led->enable = devm_regmap_field_alloc(dev,
+					chip->regmap, kt20xx_c4_enable);
+			break;
+		}
+
+		ret = devm_led_classdev_multicolor_register_ext(dev,
+			&led->mc_cdev,
+			&init_data);
+
+		if (ret) {
+			dev_err(dev, "led register err: %d\n", ret);
+			goto child_out;
+		}
+
+		i++;
+	}
+
+	return 0;
+
+child_out:
+	fwnode_handle_put(child);
+	return ret;
+}
+
+/*
+ * The chip also offers the option "Night Mode".
+ * All LED current settings are divided by 16 for a 0 to 1.5mA current
+ * setting range.
+ */
+static ssize_t nightmode_show(struct device *dev, struct device_attribute *a,
+		char *buf)
+{
+	struct ktd20xx *chip = dev_get_drvdata(dev);
+	unsigned int value;
+
+	mutex_lock(&chip->lock);
+	regmap_field_read(chip->control_mode, &value);
+	mutex_unlock(&chip->lock);
+
+	return sysfs_emit(buf, "%d\n", value == CONTROL_MODE_NIGHT ? 1 : 0);
+}
+
+static ssize_t nightmode_store(struct device *dev, struct device_attribute *a,
+		const char *buf, size_t count)
+{
+	struct ktd20xx *chip = dev_get_drvdata(dev);
+	bool value;
+	int ret;
+
+	ret = kstrtobool(buf, &value);
+	if (ret)
+		return ret;
+
+	mutex_lock(&chip->lock);
+	ret = regmap_field_write(chip->control_mode,
+			value == 1 ? CONTROL_MODE_NIGHT : CONTROL_MODE_NORMAL);
+	mutex_unlock(&chip->lock);
+
+	if (ret)
+		return ret;
+
+	return count;
+}
+static DEVICE_ATTR_RW(nightmode);
+
+static struct attribute *ktd20xx_led_controller_attrs[] = {
+	&dev_attr_nightmode.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(ktd20xx_led_controller);
+
+static int ktd20xx_probe(struct i2c_client *client,
+		const struct i2c_device_id *id)
+{
+	struct ktd20xx *chip;
+	unsigned int vendor;
+	unsigned int chip_id;
+	unsigned int chip_rev;
+	struct device *dev;
+	int ret;
+
+	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	mutex_init(&chip->lock);
+	chip->client = client;
+	dev = &client->dev;
+	i2c_set_clientdata(client, chip);
+
+	chip->regmap = devm_regmap_init_i2c(client, &ktd20xx_regmap_config);
+	if (IS_ERR(chip->regmap)) {
+		dev_err_probe(dev, PTR_ERR(chip->regmap),
+			"Failed to allocate register map\n");
+		goto error;
+	}
+
+	chip->control_mode = devm_regmap_field_alloc(dev, chip->regmap,
+			kt20xx_control_mode);
+	chip->faderate = devm_regmap_field_alloc(dev, chip->regmap,
+			kt20xx_faderate);
+	chip->vendor = devm_regmap_field_alloc(dev, chip->regmap,
+			kt20xx_vendor);
+	chip->chip_id = devm_regmap_field_alloc(dev, chip->regmap,
+			kt20xx_chip_id);
+	chip->chip_rev = devm_regmap_field_alloc(dev, chip->regmap,
+			kt20xx_chip_rev);
+
+	/* Reset all registers to hardware device default settings */
+	regmap_field_write(chip->control_mode, CONTROL_MODE_RESET);
+
+	ret = regmap_field_read(chip->vendor, &vendor);
+	if (ret) {
+		dev_err_probe(dev, ret, "Failed to read vendor\n");
+		goto error;
+	}
+
+	ret = regmap_field_read(chip->chip_id, &chip_id);
+	if (ret) {
+		dev_err_probe(dev, ret, "Failed to read chip id\n");
+		goto error;
+	}
+
+	ret = regmap_field_read(chip->chip_rev, &chip_rev);
+	if (ret) {
+		dev_err_probe(dev, ret, "Failed to read chip rev\n");
+		goto error;
+	}
+
+	dev_info(dev, "vendor: 0x%02x chip-id: 0x%02x chip-rev: 0x%02x\n",
+			vendor, chip_id, chip_rev);
+
+	ret = ktd20xx_probe_dt(chip);
+	if (ret)
+		goto error;
+
+	ret = ktd20xx_hwinit(chip);
+	if (ret)
+		goto error;
+
+	return 0;
+
+error:
+	return ret;
+}
+
+static int ktd20xx_remove(struct i2c_client *client)
+{
+	struct ktd20xx *chip = i2c_get_clientdata(client);
+
+	mutex_lock(&chip->lock);
+	regmap_field_write(chip->control_mode, CONTROL_MODE_OFF);
+	mutex_unlock(&chip->lock);
+
+	return 0;
+}
+
+static const struct i2c_device_id ktd20xx_id[] = {
+	{ "ktd20xx", 0 },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, ktd20xx_id);
+
+static const struct of_device_id of_ktd20xx_leds_match[] = {
+	{ .compatible = "kinetic,ktd20xx", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, of_ktd20xx_leds_match);
+
+static struct i2c_driver ktd20xx_driver = {
+	.driver = {
+		.name = "ktd20xx",
+		.dev_groups = ktd20xx_led_controller_groups,
+		.of_match_table = of_ktd20xx_leds_match,
+	},
+	.probe = ktd20xx_probe,
+	.remove = ktd20xx_remove,
+	.id_table = ktd20xx_id
+};
+module_i2c_driver(ktd20xx_driver);
+
+MODULE_DESCRIPTION("Kinetic KTD20xx LED driver");
+MODULE_AUTHOR("Florian Eckert <fe@dev.tdt.de>");
+MODULE_LICENSE("GPL v2");
-- 
2.20.1

Re: [PATCH v4 1/2] leds: ktd20xx: Extension of the KTD20xx family of LED drivers from Kinetic

[Andy Shevchenko]

On Fri, Jan 21, 2022 at 4:01 PM Florian Eckert <fe@dev.tdt.de> wrote:
>
> Introducing the KTD2061/58/59/60 RGB LED drivers. The difference in
> these are the address numbers on the I2C bus that the device listens to.
>
> All KT20xx units can drive up to 12 LEDs.
>
> Due to the hardware limitation, we can only set 7 colors and the color
> black (LED off) for each LED independently and not the full RGB range.
> This is because the chip only has two color registers.
>
> To control the LEDs independently, the chip has to be configured in a
> special way.
>
> Color register 0 must be loaded with the current value 0mA, and color
> register 1 must be loaded with the value 'kinetic,led-current' from the
> device tree node. If the property is omitted, the register is loaded
> with the default value (0x28 = 5mA).
>
> To select a color for an LED, a combination must be written to the color
> selection register of that LED. This range for selecting the value is 3
> bits wide (RGB). A '0' in any of the bits uses color register '0' and a
> '1' uses color register '1'.
>
> So we could choose the following combination for each LED:
> R G B
> 0 0 0 = Black (off)
> 0 0 1 = Blue
> 0 1 0 = green
> 0 1 1 = Cyan
> 1 0 0 = Red
> 1 0 1 = Magenta
> 1 1 0 = Yellow
> 1 1 1 = White

...

> +/*
> + *  LEDs driver for the Kinetic KDT20xx device
> + *
> + *  Copyright (C) 2021 TDT AG Florian Eckert <fe@dev.tdt.de>

> + *

Redundant (blank) line.

> + */

...

> +static const struct reg_default ktd20xx_reg_defs[] = {
> +       /* Color0 Configuration Registers */
> +       {KTD20XX_IRED0, 0x28},
> +       {KTD20XX_IGRN0, 0x28},
> +       {KTD20XX_IBLU0, 0x28},
> +       /* Color1 Configuration Registers */
> +       {KTD20XX_IRED1, 0x60},
> +       {KTD20XX_IGRN1, 0x60},
> +       {KTD20XX_IBLU1, 0x60},
> +       /* Selection Configuration Register */
> +       {KTD20XX_ISELA12, 0x00},
> +       {KTD20XX_ISELA34, 0x00},
> +       {KTD20XX_ISELB12, 0x00},
> +       {KTD20XX_ISELB34, 0x00},
> +       {KTD20XX_ISELC12, 0x00},

> +       {KTD20XX_ISELC34, 0x00}

+ Comma?

> +};

...

> +       struct device *dev = &chip->client->dev;
> +       int ret;
> +       unsigned int value;

Here and everywhere can you use reverse xmas tree ordering?

       struct device *dev = &chip->client->dev;
       unsigned int value;
       int ret;

...

> +       /*
> +        * If the device tree property 'kinetc,led-current' is found
> +        * then set this value into the color0 register as the max current
> +        * for all color channel LEDs. If this poperty is not set then

property

> +        * use the default value 0x28 set by the chip after a hardware reset.
> +        * The hardware default value 0x28 corresponds to 5mA.
> +        */

...


> +                       set_bit(channel, &rgb);

__set_bit() will be sufficient here (no need an atomic version)

...

> +       /*
> +        * To use the color0 registers default value after an hadware reset,

hardware

> +        * if the device tree property 'kinetc,led-current' is not set,
> +        * we have to 'invert' the rgb channel!
> +        */

...

> +unlock_out:

out_unlock is more usual, but it's up to you.


...

> +       chip->regmap = devm_regmap_init_i2c(client, &ktd20xx_regmap_config);
> +       if (IS_ERR(chip->regmap)) {

> +               dev_err_probe(dev, PTR_ERR(chip->regmap),
> +                       "Failed to allocate register map\n");
> +               goto error;

return dev_err_probe(...);

> +       }

...

> +       ret = regmap_field_read(chip->vendor, &vendor);
> +       if (ret) {

> +               dev_err_probe(dev, ret, "Failed to read vendor\n");
> +               goto error;

Ditto.

> +       }
> +
> +       ret = regmap_field_read(chip->chip_id, &chip_id);
> +       if (ret) {

> +               dev_err_probe(dev, ret, "Failed to read chip id\n");
> +               goto error;

Ditto,

> +       }
> +
> +       ret = regmap_field_read(chip->chip_rev, &chip_rev);
> +       if (ret) {
> +               dev_err_probe(dev, ret, "Failed to read chip rev\n");
> +               goto error;

Ditto.

> +       }

...

> +       dev_info(dev, "vendor: 0x%02x chip-id: 0x%02x chip-rev: 0x%02x\n",
> +                       vendor, chip_id, chip_rev);

Why on the info level?

...

> +       ret = ktd20xx_probe_dt(chip);
> +       if (ret)

return ret;

> +               goto error;
> +
> +       ret = ktd20xx_hwinit(chip);
> +       if (ret)
> +               goto error;

Ditto.

...

> +error:
> +       return ret;

Unneeded label, see above.

...

> +static struct i2c_driver ktd20xx_driver = {
> +       .driver = {
> +               .name = "ktd20xx",
> +               .dev_groups = ktd20xx_led_controller_groups,
> +               .of_match_table = of_ktd20xx_leds_match,
> +       },

> +       .probe = ktd20xx_probe,

Why not .probe_new?

> +       .remove = ktd20xx_remove,

> +       .id_table = ktd20xx_id

+ Comma.

> +};

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v4 1/2] leds: ktd20xx: Extension of the KTD20xx family of LED drivers from Kinetic

[Pavel Machek]

[-- Attachment #1: Type: text/plain, Size: 402 bytes --]

Hi!


> > +       struct device *dev = &chip->client->dev;
> > +       int ret;
> > +       unsigned int value;
> 
> Here and everywhere can you use reverse xmas tree ordering?
> 
>        struct device *dev = &chip->client->dev;
>        unsigned int value;
>        int ret;

Lets not ask people to do that.

Best regards,
								Pavel
-- 
http://www.livejournal.com/~pavelmachek

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 195 bytes --]

Re: [PATCH v4 1/2] leds: ktd20xx: Extension of the KTD20xx family of LED drivers from Kinetic

[Florian Eckert]

Hello Pavel,

Haven't seen the new ktd20xx for the next [1] kernel release yet.
Do I still have to do something?

Best regards,

Florian Eckert

[1] 
https://git.kernel.org/pub/scm/linux/kernel/git/pavel/linux-leds.git/log/?h=for-next

Re: [PATCH v4 1/2] leds: ktd20xx: Extension of the KTD20xx family of LED drivers from Kinetic

[kernel test robot]

Hi Florian,

I love your patch! Perhaps something to improve:

[auto build test WARNING on pavel-leds/for-next]
[also build test WARNING on robh/for-next linux/master linus/master v5.17-rc1 next-20220124]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Florian-Eckert/leds-add-ktd20xx-LED-driver-support/20220121-220338
base:   git://git.kernel.org/pub/scm/linux/kernel/git/pavel/linux-leds.git for-next
config: i386-allmodconfig (https://download.01.org/0day-ci/archive/20220125/202201251140.YNV7J1Ot-lkp@intel.com/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 2e58a18910867ba6795066e044293e6daf89edf5)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/8e24c9cc5b5a807f40eec9cc643c2ea43f75e8a3
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Florian-Eckert/leds-add-ktd20xx-LED-driver-support/20220121-220338
        git checkout 8e24c9cc5b5a807f40eec9cc643c2ea43f75e8a3
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash arch/x86/kvm/ drivers/leds/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/leds/leds-ktd20xx.c:490:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
           if (IS_ERR(chip->regmap)) {
               ^~~~~~~~~~~~~~~~~~~~
   drivers/leds/leds-ktd20xx.c:542:9: note: uninitialized use occurs here
           return ret;
                  ^~~
   drivers/leds/leds-ktd20xx.c:490:2: note: remove the 'if' if its condition is always false
           if (IS_ERR(chip->regmap)) {
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/leds/leds-ktd20xx.c:478:9: note: initialize the variable 'ret' to silence this warning
           int ret;
                  ^
                   = 0
   1 warning generated.


vim +490 drivers/leds/leds-ktd20xx.c

   469	
   470	static int ktd20xx_probe(struct i2c_client *client,
   471			const struct i2c_device_id *id)
   472	{
   473		struct ktd20xx *chip;
   474		unsigned int vendor;
   475		unsigned int chip_id;
   476		unsigned int chip_rev;
   477		struct device *dev;
   478		int ret;
   479	
   480		chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
   481		if (!chip)
   482			return -ENOMEM;
   483	
   484		mutex_init(&chip->lock);
   485		chip->client = client;
   486		dev = &client->dev;
   487		i2c_set_clientdata(client, chip);
   488	
   489		chip->regmap = devm_regmap_init_i2c(client, &ktd20xx_regmap_config);
 > 490		if (IS_ERR(chip->regmap)) {
   491			dev_err_probe(dev, PTR_ERR(chip->regmap),
   492				"Failed to allocate register map\n");
   493			goto error;
   494		}
   495	
   496		chip->control_mode = devm_regmap_field_alloc(dev, chip->regmap,
   497				kt20xx_control_mode);
   498		chip->faderate = devm_regmap_field_alloc(dev, chip->regmap,
   499				kt20xx_faderate);
   500		chip->vendor = devm_regmap_field_alloc(dev, chip->regmap,
   501				kt20xx_vendor);
   502		chip->chip_id = devm_regmap_field_alloc(dev, chip->regmap,
   503				kt20xx_chip_id);
   504		chip->chip_rev = devm_regmap_field_alloc(dev, chip->regmap,
   505				kt20xx_chip_rev);
   506	
   507		/* Reset all registers to hardware device default settings */
   508		regmap_field_write(chip->control_mode, CONTROL_MODE_RESET);
   509	
   510		ret = regmap_field_read(chip->vendor, &vendor);
   511		if (ret) {
   512			dev_err_probe(dev, ret, "Failed to read vendor\n");
   513			goto error;
   514		}
   515	
   516		ret = regmap_field_read(chip->chip_id, &chip_id);
   517		if (ret) {
   518			dev_err_probe(dev, ret, "Failed to read chip id\n");
   519			goto error;
   520		}
   521	
   522		ret = regmap_field_read(chip->chip_rev, &chip_rev);
   523		if (ret) {
   524			dev_err_probe(dev, ret, "Failed to read chip rev\n");
   525			goto error;
   526		}
   527	
   528		dev_info(dev, "vendor: 0x%02x chip-id: 0x%02x chip-rev: 0x%02x\n",
   529				vendor, chip_id, chip_rev);
   530	
   531		ret = ktd20xx_probe_dt(chip);
   532		if (ret)
   533			goto error;
   534	
   535		ret = ktd20xx_hwinit(chip);
   536		if (ret)
   537			goto error;
   538	
   539		return 0;
   540	
   541	error:
   542		return ret;
   543	}
   544	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

Re: [PATCH v4 1/2] leds: ktd20xx: Extension of the KTD20xx family of LED drivers from Kinetic

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 5007 bytes --]

Hi Florian,

I love your patch! Perhaps something to improve:

[auto build test WARNING on pavel-leds/for-next]
[also build test WARNING on robh/for-next linux/master linus/master v5.17-rc1 next-20220124]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Florian-Eckert/leds-add-ktd20xx-LED-driver-support/20220121-220338
base:   git://git.kernel.org/pub/scm/linux/kernel/git/pavel/linux-leds.git for-next
config: i386-allmodconfig (https://download.01.org/0day-ci/archive/20220125/202201251140.YNV7J1Ot-lkp(a)intel.com/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 2e58a18910867ba6795066e044293e6daf89edf5)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/8e24c9cc5b5a807f40eec9cc643c2ea43f75e8a3
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Florian-Eckert/leds-add-ktd20xx-LED-driver-support/20220121-220338
        git checkout 8e24c9cc5b5a807f40eec9cc643c2ea43f75e8a3
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash arch/x86/kvm/ drivers/leds/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/leds/leds-ktd20xx.c:490:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
           if (IS_ERR(chip->regmap)) {
               ^~~~~~~~~~~~~~~~~~~~
   drivers/leds/leds-ktd20xx.c:542:9: note: uninitialized use occurs here
           return ret;
                  ^~~
   drivers/leds/leds-ktd20xx.c:490:2: note: remove the 'if' if its condition is always false
           if (IS_ERR(chip->regmap)) {
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/leds/leds-ktd20xx.c:478:9: note: initialize the variable 'ret' to silence this warning
           int ret;
                  ^
                   = 0
   1 warning generated.


vim +490 drivers/leds/leds-ktd20xx.c

   469	
   470	static int ktd20xx_probe(struct i2c_client *client,
   471			const struct i2c_device_id *id)
   472	{
   473		struct ktd20xx *chip;
   474		unsigned int vendor;
   475		unsigned int chip_id;
   476		unsigned int chip_rev;
   477		struct device *dev;
   478		int ret;
   479	
   480		chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
   481		if (!chip)
   482			return -ENOMEM;
   483	
   484		mutex_init(&chip->lock);
   485		chip->client = client;
   486		dev = &client->dev;
   487		i2c_set_clientdata(client, chip);
   488	
   489		chip->regmap = devm_regmap_init_i2c(client, &ktd20xx_regmap_config);
 > 490		if (IS_ERR(chip->regmap)) {
   491			dev_err_probe(dev, PTR_ERR(chip->regmap),
   492				"Failed to allocate register map\n");
   493			goto error;
   494		}
   495	
   496		chip->control_mode = devm_regmap_field_alloc(dev, chip->regmap,
   497				kt20xx_control_mode);
   498		chip->faderate = devm_regmap_field_alloc(dev, chip->regmap,
   499				kt20xx_faderate);
   500		chip->vendor = devm_regmap_field_alloc(dev, chip->regmap,
   501				kt20xx_vendor);
   502		chip->chip_id = devm_regmap_field_alloc(dev, chip->regmap,
   503				kt20xx_chip_id);
   504		chip->chip_rev = devm_regmap_field_alloc(dev, chip->regmap,
   505				kt20xx_chip_rev);
   506	
   507		/* Reset all registers to hardware device default settings */
   508		regmap_field_write(chip->control_mode, CONTROL_MODE_RESET);
   509	
   510		ret = regmap_field_read(chip->vendor, &vendor);
   511		if (ret) {
   512			dev_err_probe(dev, ret, "Failed to read vendor\n");
   513			goto error;
   514		}
   515	
   516		ret = regmap_field_read(chip->chip_id, &chip_id);
   517		if (ret) {
   518			dev_err_probe(dev, ret, "Failed to read chip id\n");
   519			goto error;
   520		}
   521	
   522		ret = regmap_field_read(chip->chip_rev, &chip_rev);
   523		if (ret) {
   524			dev_err_probe(dev, ret, "Failed to read chip rev\n");
   525			goto error;
   526		}
   527	
   528		dev_info(dev, "vendor: 0x%02x chip-id: 0x%02x chip-rev: 0x%02x\n",
   529				vendor, chip_id, chip_rev);
   530	
   531		ret = ktd20xx_probe_dt(chip);
   532		if (ret)
   533			goto error;
   534	
   535		ret = ktd20xx_hwinit(chip);
   536		if (ret)
   537			goto error;
   538	
   539		return 0;
   540	
   541	error:
   542		return ret;
   543	}
   544	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

[PATCH v4 2/2] dt: bindings: KTD20xx: Introduce the ktd20xx family of RGB drivers

[Florian Eckert]

Introduce the bindings for the Kinetic KTD2061/58/59/60RGB LED device
driver. The KTD20xx can control RGB LEDs individually. Because of the
hardware limitations, only 7 colors and the color black (off) can be set.

Signed-off-by: Florian Eckert <fe@dev.tdt.de>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../bindings/leds/leds-ktd20xx.yaml           | 130 ++++++++++++++++++
 MAINTAINERS                                   |   1 +
 2 files changed, 131 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/leds-ktd20xx.yaml

diff --git a/Documentation/devicetree/bindings/leds/leds-ktd20xx.yaml b/Documentation/devicetree/bindings/leds/leds-ktd20xx.yaml
new file mode 100644
index 000000000000..c4e440cc6945
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/leds-ktd20xx.yaml
@@ -0,0 +1,130 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/leds-ktd20xx.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: LED driver for KTD20xx RGB LED from Kinetic.
+
+maintainers:
+  - Florian Eckert <fe@dev.tdt.de>
+
+description: |
+  The KTD20XX is multi-channel, I2C LED driver. Into can control up to 12
+  LEDs per device. The RGB value can be set for each LED. Due to hardware
+  limitations, the full RGB range cannot be used. Only 7 colors and the
+  color black can be set (black means off).
+  R G B
+  0 0 0 = Black (off)
+  0 0 1 = Blue
+  0 1 0 = Green
+  0 1 1 = Cyan
+  1 0 0 = Red
+  1 0 1 = Magenta
+  1 1 0 = Yellow
+  1 1 1 = White
+
+properties:
+  compatible:
+    enum:
+      - kinetic,ktd20xx
+
+  reg:
+    maxItems: 1
+    description:
+      I2C slave address
+      ktd2061/58/59/60 0x68 0x69 0x6A 0x6B
+
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+  'kinetic,led-current':
+    $ref: /schemas/types.yaml#/definitions/uint8
+    description:
+      This value is a current setting for all LEDs connected to this device.
+      If this value is not set then the default value off 0x28 (5mA) is set.
+      This means all LEDs get 5mA. The max value is 24mA. We have the
+      following mapping in 125uA steps. We can set a maximum of 24mA.
+      0000 0000 (0x00) = 0uA
+      0000 0001 (0x01) = 125uA
+      .... ....
+      0010 1000 (0x28) = 5mA
+      .... ....
+      1100 0000 (0xC0) = 24mA
+      1100 0001 (0xC1) = 24mA
+      .... ....
+      1111 1111 (0xFF) = 24mA
+    minimum: 0
+    maximum: 255
+
+patternProperties:
+  '^multi-led@[0-9a-f]$':
+    type: object
+    allOf:
+      - $ref: leds-class-multicolor.yaml#
+    description:
+      This node represents one of the Multicolor LED. No subnodes need to
+      be added for subchannels since this controller only supports 1bit
+      RGB values. We could display seven different colors and the color
+      black which means off.
+
+    properties:
+      reg:
+        minimum: 0
+        maximum: 11
+        description:
+          This property identifies wired connection of the LED to this device.
+          0x00  LEDA1
+          0x01  LEDA2
+          0x02  LEDA3
+          0x03  LEDA4
+          0x04  LEDB1
+          0x05  LEDB2
+          0x06  LEDB3
+          0x07  LEDB4
+          0x08  LEDC1
+          0x09  LEDC2
+          0x0A  LEDC3
+          0x0B  LEDC4
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+   #include <dt-bindings/leds/common.h>
+
+   i2c {
+       #address-cells = <1>;
+       #size-cells = <0>;
+
+       led-controller@14 {
+           compatible = "kinetic,ktd20xx";
+           reg = <0x68>;
+           #address-cells = <1>;
+           #size-cells = <0>;
+           kinetic,led-current = <0x28>; // Current for all LEDs is 5mA
+
+           multi-led@0 {
+               reg = <0x0>;
+               color = <LED_COLOR_ID_MULTI>;
+               function = LED_FUNCTION_CHARGING;
+               linux,default-trigger = "default-on";
+          };
+
+          multi-led@2 {
+            reg = <0x2>;
+            color = <LED_COLOR_ID_MULTI>;
+            function = LED_FUNCTION_STANDBY;
+            linux,default-trigger = "default-on";
+         };
+       };
+    };
+
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index 04d68985d348..b56d8392119c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10743,6 +10743,7 @@ KTD20XX LED CONTROLLER DRIVER
 M:	Florian Eckert <fe@dev.tdt.de>
 L:	linux-leds@vger.kernel.org
 S:	Maintained
+F:	Documentation/devicetree/bindings/leds/leds-ktd20xx.yaml
 F:	drivers/leds/leds-ktd20xx.c
 
 KTEST
-- 
2.20.1