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From:   Florian Eckert <fe@dev.tdt.de>
To:     pavel@ucw.cz, robh+dt@kernel.org, Eckert.Florian@googlemail.com
Cc:     linux-leds@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, Florian Eckert <fe@dev.tdt.de>
Subject: [PATCH 1/2] leds: ktd20xx: Add the KTD20xx family of the RGB LEDs driver from Kinetic
Date:   Tue,  9 Nov 2021 11:08:21 +0100
Message-ID: <20211109100822.5412-2-fe@dev.tdt.de>
In-Reply-To: <20211109100822.5412-1-fe@dev.tdt.de>
References: <20211109100822.5412-1-fe@dev.tdt.de>
MIME-Version: 1.0
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Introduce the KTD2061/58/59/60 RGB LEDs driver. The difference in these
parts are the address number on the I2C bus the device is listen on.

All KT20xx device could control up to 12 LEDs. The chip can be operated
in two variants.

Variant 1:
The device has the ability to group LED outputs into two banks so that
the two LED banks can be controlled with the same color. This could not
be done via the LEDs 'sysfs' entry because of the limitation on the color
register count. The color of the two banks can be configured via device
'sysfs' entry for all LEDs at once [current_color0|current_color1].
Which color the LED is to be used can be set via the 'sysfs' of the
individual LEDs via the 'multi_intensity' file. Valid values for the
colors (RGB) are 0 | 1. The value 0 selects the color register 0 and the
value 1 selects the color register 1.

Variant 2:
The device can also set the LED color independently. Since the chip only
has two color registers, but we want to control the 12 LEDs
independently via the 'led-class-multicolour' sysfs entry,
the full RGB color depth cannot be used. Due to this limitation, only 7
colors and the color black (off) can be set. To use this mode the color
registers must be preset via the device tree or the device 'sysfs'. The
color registers 0 must be preset with 0x00 (Red=3D0x00 Green=3D0x00 Blue=3D=
0x00).
The color register1 should be preset all with the same value. This value
depends on which light intensity is to be used in the setup.

Signed-off-by: Florian Eckert <fe@dev.tdt.de>
---
 MAINTAINERS                 |   6 +
 drivers/leds/Kconfig        |  13 +
 drivers/leds/Makefile       |   1 +
 drivers/leds/leds-ktd20xx.c | 801 ++++++++++++++++++++++++++++++++++++
 4 files changed, 821 insertions(+)
 create mode 100644 drivers/leds/leds-ktd20xx.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 9096c64d8d09..736d564f7e93 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10603,6 +10603,12 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/leds/backlight/kinetic,ktd253.yaml
 F:	drivers/video/backlight/ktd253-backlight.c
=20
+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 ed800f5da7d8..b313b5c6a445 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -157,6 +157,19 @@ config LEDS_EL15203000
 	  To compile this driver as a module, choose M here: the module
 	  will be called leds-el15203000.
=20
+config LEDS_KTD20XX
+	tristate "LED Support for KTD2061/58/59/60 LED driver chip"
+	depends on LEDS_CLASS && I2C
+	depends on LEDS_CLASS_MULTICOLOR || !LEDS_CLASS_MULTICOLOR
+	depends on OF
+	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 c636ec069612..7004ec953c87 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -35,6 +35,7 @@ obj-$(CONFIG_LEDS_IP30)			+=3D leds-ip30.o
 obj-$(CONFIG_LEDS_IPAQ_MICRO)		+=3D leds-ipaq-micro.o
 obj-$(CONFIG_LEDS_IS31FL319X)		+=3D leds-is31fl319x.o
 obj-$(CONFIG_LEDS_IS31FL32XX)		+=3D leds-is31fl32xx.o
+obj-${CONFIG_LEDS_KTD20XX}		+=3D leds-ktd20xx.o
 obj-$(CONFIG_LEDS_LM3530)		+=3D leds-lm3530.o
 obj-$(CONFIG_LEDS_LM3532)		+=3D leds-lm3532.o
 obj-$(CONFIG_LEDS_LM3533)		+=3D leds-lm3533.o
diff --git a/drivers/leds/leds-ktd20xx.c b/drivers/leds/leds-ktd20xx.c
new file mode 100644
index 000000000000..ffe125c2f7d9
--- /dev/null
+++ b/drivers/leds/leds-ktd20xx.c
@@ -0,0 +1,801 @@
+// 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/module.h>
+#include <linux/mutex.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_rgb {
+	RED,
+	GRN,
+	BLU,
+};
+
+enum ktd20xx_control_mode {
+	CONTROL_MODE_OFF,
+	CONTROL_MODE_NIGHT,
+	CONTROL_MODE_NORMAL,
+	CONTROL_MODE_RESET,
+};
+
+static const struct reg_default ktd20xx_reg_defs[] =3D {
+	/* 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 =3D REG_FIELD(KTD20XX_=
CONTROL, 6, 7);
+static const struct reg_field kt20xx_faderate =3D REG_FIELD(KTD20XX_CONT=
ROL, 0, 2);
+static const struct reg_field kt20xx_vendor =3D REG_FIELD(KTD20XX_ID, 5,=
 7);
+static const struct reg_field kt20xx_chip_id =3D REG_FIELD(KTD20XX_ID, 0=
, 4);
+static const struct reg_field kt20xx_chip_rev =3D REG_FIELD(KTD20XX_MONI=
TOR, 4, 7);
+
+/* ISELA1 and ISELA2 */
+static const struct reg_field kt20xx_a1_select =3D REG_FIELD(KTD20XX_ISE=
LA12, 4, 6);
+static const struct reg_field kt20xx_a1_enable =3D REG_FIELD(KTD20XX_ISE=
LA12, 7, 7);
+static const struct reg_field kt20xx_a2_select =3D REG_FIELD(KTD20XX_ISE=
LA12, 0, 2);
+static const struct reg_field kt20xx_a2_enable =3D REG_FIELD(KTD20XX_ISE=
LA12, 3, 3);
+
+/* ISELA3 and ISELA4 */
+static const struct reg_field kt20xx_a3_select =3D REG_FIELD(KTD20XX_ISE=
LA34, 4, 6);
+static const struct reg_field kt20xx_a3_enable =3D REG_FIELD(KTD20XX_ISE=
LA34, 7, 7);
+static const struct reg_field kt20xx_a4_select =3D REG_FIELD(KTD20XX_ISE=
LA34, 0, 2);
+static const struct reg_field kt20xx_a4_enable =3D REG_FIELD(KTD20XX_ISE=
LA34, 3, 3);
+
+/* ISELB1 and ISELB2 */
+static const struct reg_field kt20xx_b1_select =3D REG_FIELD(KTD20XX_ISE=
LB12, 4, 6);
+static const struct reg_field kt20xx_b1_enable =3D REG_FIELD(KTD20XX_ISE=
LB12, 7, 7);
+static const struct reg_field kt20xx_b2_select =3D REG_FIELD(KTD20XX_ISE=
LB12, 0, 2);
+static const struct reg_field kt20xx_b2_enable =3D REG_FIELD(KTD20XX_ISE=
LB12, 3, 3);
+
+/* ISELB3 and ISELB4 */
+static const struct reg_field kt20xx_b3_select =3D REG_FIELD(KTD20XX_ISE=
LB34, 4, 6);
+static const struct reg_field kt20xx_b3_enable =3D REG_FIELD(KTD20XX_ISE=
LB34, 7, 7);
+static const struct reg_field kt20xx_b4_select =3D REG_FIELD(KTD20XX_ISE=
LB34, 0, 2);
+static const struct reg_field kt20xx_b4_enable =3D REG_FIELD(KTD20XX_ISE=
LB34, 3, 3);
+
+/* ISELC1 and ISELC2 */
+static const struct reg_field kt20xx_c1_select =3D REG_FIELD(KTD20XX_ISE=
LC12, 4, 6);
+static const struct reg_field kt20xx_c1_enable =3D REG_FIELD(KTD20XX_ISE=
LC12, 7, 7);
+static const struct reg_field kt20xx_c2_select =3D REG_FIELD(KTD20XX_ISE=
LC12, 0, 2);
+static const struct reg_field kt20xx_c2_enable =3D REG_FIELD(KTD20XX_ISE=
LC12, 3, 3);
+
+/* ISELC3 and ISELC4 */
+static const struct reg_field kt20xx_c3_select =3D REG_FIELD(KTD20XX_ISE=
LC34, 4, 6);
+static const struct reg_field kt20xx_c3_enable =3D REG_FIELD(KTD20XX_ISE=
LC34, 7, 7);
+static const struct reg_field kt20xx_c4_select =3D REG_FIELD(KTD20XX_ISE=
LC34, 0, 2);
+static const struct reg_field kt20xx_c4_enable =3D REG_FIELD(KTD20XX_ISE=
LC34, 3, 3);
+
+static const struct regmap_range ktd20xx_volatile_ranges =3D {
+	.range_min =3D KTD20XX_ID,
+	.range_max =3D KTD20XX_CONTROL,
+};
+
+static const struct regmap_access_table ktd20xx_volatile_table =3D {
+	.yes_ranges =3D &ktd20xx_volatile_ranges,
+	.n_yes_ranges =3D 1,
+};
+
+static const struct regmap_range ktd20xx_readable_ranges =3D {
+	.range_min =3D KTD20XX_ID,
+	.range_max =3D KTD20XX_MONITOR,
+};
+
+static const struct regmap_access_table ktd20xx_readable_table =3D {
+	.yes_ranges =3D &ktd20xx_readable_ranges,
+	.n_yes_ranges =3D 1,
+};
+
+static const struct regmap_config ktd20xx_regmap_config =3D {
+	.name =3D "ktd20xx_regmap",
+	.reg_bits =3D 8,
+	.val_bits =3D 8,
+
+	.max_register =3D KTD20XX_ISELC34,
+
+	.volatile_table =3D &ktd20xx_volatile_table,
+	.rd_table =3D &ktd20xx_readable_table,
+
+	.reg_defaults =3D ktd20xx_reg_defs,
+	.num_reg_defaults =3D ARRAY_SIZE(ktd20xx_reg_defs),
+	.cache_type =3D 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 device *dev;
+	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 fwnode_handle *fwnode;
+	struct device *dev =3D &chip->client->dev;
+	u8 value[3];
+
+	fwnode =3D dev_fwnode(dev);
+
+	if (fwnode_property_read_u8_array(fwnode, "kinetic,color-current0", val=
ue, 3)) {
+		dev_warn(dev, "no kinetic,color-current0 property, use chip default va=
lue 0x28.\n");
+	} else {
+		regmap_write(chip->regmap, KTD20XX_IRED0, value[0]);
+		regmap_write(chip->regmap, KTD20XX_IGRN0, value[1]);
+		regmap_write(chip->regmap, KTD20XX_IBLU0, value[2]);
+	}
+
+	if (fwnode_property_read_u8_array(fwnode, "kinetic,color-current1", val=
ue, 3)) {
+		dev_warn(dev, "no kinetic,color-current1 property, use chip default va=
lue 0x60.\n");
+	} else {
+		regmap_write(chip->regmap, KTD20XX_IRED1, value[0]);
+		regmap_write(chip->regmap, KTD20XX_IGRN1, value[1]);
+		regmap_write(chip->regmap, KTD20XX_IBLU1, value[2]);
+	}
+
+	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 =3D lcdev_to_mccdev(cdev);
+	struct ktd20xx_led *led =3D mcled_cdev_to_led(mc_dev);
+	struct device *dev =3D led->chip->dev;
+	int ret =3D 0;
+	int i =3D 0;
+	unsigned int rgb =3D 0;
+	unsigned int bit =3D 0;
+
+	mutex_lock(&led->chip->lock);
+	if (brightness > 0)
+		ret =3D regmap_field_write(led->enable, 1);
+	else
+		ret =3D regmap_field_write(led->enable, 0);
+
+	if (ret) {
+		dev_err(dev, "Cannot set enable flag of LED %d error: %d\n",
+				led->index, ret);
+		goto out;
+	}
+
+	for (i =3D 0; i < led->mc_cdev.num_colors; i++) {
+		unsigned int intensity =3D mc_dev->subled_info[i].intensity;
+
+		switch (i) {
+		case RED:
+			bit =3D 4;
+			break;
+		case GRN:
+			bit =3D 2;
+			break;
+		case BLU:
+			bit =3D 1;
+			break;
+		}
+
+		if (intensity > 0)
+			rgb +=3D bit;
+	}
+
+	ret =3D 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 out;
+	}
+
+out:
+	mutex_unlock(&led->chip->lock);
+	return ret;
+}
+
+static int ktd20xx_probe_dt(struct ktd20xx *chip)
+{
+	struct fwnode_handle *child =3D NULL;
+	struct led_init_data init_data =3D {};
+	struct led_classdev *led_cdev;
+	struct ktd20xx_led *led;
+	struct device *dev =3D &chip->client->dev;
+	u8 value[3] =3D { 0, 0, 0 };
+	int i =3D 0;
+	int ret =3D -EINVAL;
+	int color;
+
+	device_for_each_child_node(chip->dev, child) {
+		led =3D &chip->leds[i];
+
+		ret =3D fwnode_property_read_u32(child, "reg", &led->index);
+		if (ret) {
+			dev_err(dev, "missing property: reg\n");
+			goto child_out;
+		}
+		if (led->index >=3D KTD20XX_MAX_LEDS) {
+			dev_warn(dev, "property 'reg' must contain value between '0' and '%i'=
\n",
+					KTD20XX_MAX_LEDS);
+			goto child_out;
+		}
+
+		ret =3D fwnode_property_read_u32(child, "color", &color);
+		if (ret) {
+			dev_err(dev, "missing property: color\n");
+			goto child_out;
+		}
+		if (color !=3D LED_COLOR_ID_RGB) {
+			dev_warn(dev, "property 'color' must contain value 'LED_COLOR_ID_RGB'=
\n");
+			goto child_out;
+		}
+
+		/* Get default color register selection */
+		if (fwnode_property_read_u8_array(child, "kinetic,color-selection", va=
lue, 3))
+			dev_warn(dev, "no kinetic,color-selection property found, use default=
 rgbt color selection from register 0.\n");
+
+		led->subled_info[0].color_index =3D LED_COLOR_ID_RED;
+		led->subled_info[0].channel =3D 0;
+		led->subled_info[0].intensity =3D value[0];
+		led->subled_info[1].color_index =3D LED_COLOR_ID_GREEN;
+		led->subled_info[1].channel =3D 1;
+		led->subled_info[1].intensity =3D value[1];
+		led->subled_info[2].color_index =3D LED_COLOR_ID_BLUE;
+		led->subled_info[2].channel =3D 2;
+		led->subled_info[2].intensity =3D value[2];
+
+		led->mc_cdev.subled_info =3D led->subled_info;
+		led->mc_cdev.num_colors =3D KTD20XX_LED_CHANNELS;
+
+		init_data.fwnode =3D child;
+
+		led->chip =3D chip;
+		led_cdev =3D &led->mc_cdev.led_cdev;
+		led_cdev->brightness_set_blocking =3D ktd20xx_brightness_set;
+
+		switch (led->index) {
+		case RGB_A1:
+			led->select =3D devm_regmap_field_alloc(chip->dev,
+					chip->regmap, kt20xx_a1_select);
+			led->enable =3D devm_regmap_field_alloc(chip->dev,
+					chip->regmap, kt20xx_a1_enable);
+			break;
+		case RGB_A2:
+			led->select =3D devm_regmap_field_alloc(chip->dev,
+					chip->regmap, kt20xx_a2_select);
+			led->enable =3D devm_regmap_field_alloc(chip->dev,
+					chip->regmap, kt20xx_a2_enable);
+			break;
+		case RGB_A3:
+			led->select =3D devm_regmap_field_alloc(chip->dev,
+					chip->regmap, kt20xx_a3_select);
+			led->enable =3D devm_regmap_field_alloc(chip->dev,
+					chip->regmap, kt20xx_a3_enable);
+			break;
+		case RGB_A4:
+			led->select =3D devm_regmap_field_alloc(chip->dev,
+					chip->regmap, kt20xx_a4_select);
+			led->enable =3D devm_regmap_field_alloc(chip->dev,
+					chip->regmap, kt20xx_a4_enable);
+			break;
+		case RGB_B1:
+			led->select =3D devm_regmap_field_alloc(chip->dev,
+					chip->regmap, kt20xx_b1_select);
+			led->enable =3D devm_regmap_field_alloc(chip->dev,
+					chip->regmap, kt20xx_b1_enable);
+			break;
+		case RGB_B2:
+			led->select =3D devm_regmap_field_alloc(chip->dev,
+					chip->regmap, kt20xx_b2_select);
+			led->enable =3D devm_regmap_field_alloc(chip->dev,
+					chip->regmap, kt20xx_b2_enable);
+			break;
+		case RGB_B3:
+			led->select =3D devm_regmap_field_alloc(chip->dev,
+					chip->regmap, kt20xx_b3_select);
+			led->enable =3D devm_regmap_field_alloc(chip->dev,
+					chip->regmap, kt20xx_b3_enable);
+			break;
+		case RGB_B4:
+			led->select =3D devm_regmap_field_alloc(chip->dev,
+					chip->regmap, kt20xx_b4_select);
+			led->enable =3D devm_regmap_field_alloc(chip->dev,
+					chip->regmap, kt20xx_b4_enable);
+			break;
+		case RGB_C1:
+			led->select =3D devm_regmap_field_alloc(chip->dev,
+					chip->regmap, kt20xx_c1_select);
+			led->enable =3D devm_regmap_field_alloc(chip->dev,
+					chip->regmap, kt20xx_c1_enable);
+			break;
+		case RGB_C2:
+			led->select =3D devm_regmap_field_alloc(chip->dev,
+					chip->regmap, kt20xx_c2_select);
+			led->enable =3D devm_regmap_field_alloc(chip->dev,
+					chip->regmap, kt20xx_c2_enable);
+			break;
+		case RGB_C3:
+			led->select =3D devm_regmap_field_alloc(chip->dev,
+					chip->regmap, kt20xx_c3_select);
+			led->enable =3D devm_regmap_field_alloc(chip->dev,
+					chip->regmap, kt20xx_c3_enable);
+			break;
+		case RGB_C4:
+			led->select =3D devm_regmap_field_alloc(chip->dev,
+					chip->regmap, kt20xx_c4_select);
+			led->enable =3D devm_regmap_field_alloc(chip->dev,
+					chip->regmap, kt20xx_c4_enable);
+			break;
+		}
+
+		ret =3D devm_led_classdev_multicolor_register_ext(&chip->client->dev,
+			&led->mc_cdev,
+			&init_data);
+
+		if (ret) {
+			dev_err(&chip->client->dev, "led register err: %d\n", ret);
+			goto child_out;
+		}
+
+		i++;
+		fwnode_handle_put(child);
+	}
+
+	return 0;
+
+child_out:
+	fwnode_handle_put(child);
+	return ret;
+}
+
+/* Device attribute for color0 register
+ *
+ * The device attribute colour1 is intended to adjust the colour space.
+ * The colour strength can be controlled via the current in 125uA steps.
+ * The maximum current for the individual channels is limited to 24mA.
+ * To set a new RGB value, 3 values must be passed. This value may not b=
e
+ * less than 0 and also not greater than 194. The chip can only process =
the
+ * maximum current of 24mA. This means that any value greater than 194
+ * cannot be set.
+ */
+static ssize_t current_color0_show(struct device *dev,
+		struct device_attribute *a,
+		char *buf)
+{
+	struct i2c_client *client =3D to_i2c_client(dev);
+	struct ktd20xx *chip =3D i2c_get_clientdata(client);
+	unsigned int value;
+	int len =3D 0;
+
+	mutex_lock(&chip->lock);
+	regmap_read(chip->regmap, KTD20XX_IRED0, &value);
+	len +=3D sprintf(buf + len, "%d", value);
+	len +=3D sprintf(buf + len, " ");
+
+	regmap_read(chip->regmap, KTD20XX_IGRN0, &value);
+	len +=3D sprintf(buf + len, "%d", value);
+	len +=3D sprintf(buf + len, " ");
+
+	regmap_read(chip->regmap, KTD20XX_IBLU0, &value);
+	len +=3D sprintf(buf + len, "%d", value);
+	mutex_unlock(&chip->lock);
+
+	buf[len++] =3D '\n';
+	return len;
+}
+
+static ssize_t current_color0_store(struct device *dev,
+		struct device_attribute *a,
+		const char *buf, size_t size)
+{
+	struct i2c_client *client =3D to_i2c_client(dev);
+	struct ktd20xx *chip =3D i2c_get_clientdata(client);
+	unsigned int value[3];
+	int i;
+	ssize_t ret;
+
+	ret =3D sscanf(buf, "%u %u %u", &value[0], &value[1], &value[2]);
+	if (ret < 3) {
+		ret =3D -EINVAL;
+		goto err_out;
+	}
+
+	for (i =3D 0; i < 3; i++) {
+		if (value[i] > 194) {
+			ret =3D -EINVAL;
+			goto err_out;
+		}
+		if (value[i] < 0) {
+			ret =3D -EINVAL;
+			goto err_out;
+		}
+	}
+
+	mutex_lock(&chip->lock);
+	regmap_write(chip->regmap, KTD20XX_IRED0, value[0]);
+	regmap_write(chip->regmap, KTD20XX_IGRN0, value[1]);
+	regmap_write(chip->regmap, KTD20XX_IBLU0, value[2]);
+	mutex_unlock(&chip->lock);
+	return size;
+
+err_out:
+	return ret;
+}
+static DEVICE_ATTR_RW(current_color0);
+
+/* Device attribute for color1 register
+ *
+ * The device attribute colour1 is intended to adjust the colour space.
+ * The colour strength can be controlled via the current in 125uA steps.
+ * The maximum current for the individual channels is limited to 24mA.
+ * To set a new RGB value, 3 values must be passed. This value may not b=
e
+ * less than 0 and also not greater than 194. The chip can only process =
the
+ * maximum current of 24mA. This means that any value greater than 194
+ * cannot be set.
+ */
+static ssize_t current_color1_show(struct device *dev,
+		struct device_attribute *a,
+		char *buf)
+{
+	struct i2c_client *client =3D to_i2c_client(dev);
+	struct ktd20xx *chip =3D i2c_get_clientdata(client);
+	unsigned int value;
+	int len =3D 0;
+
+	mutex_lock(&chip->lock);
+	regmap_read(chip->regmap, KTD20XX_IRED1, &value);
+	len +=3D sprintf(buf + len, "%d", value);
+	len +=3D sprintf(buf + len, " ");
+
+	regmap_read(chip->regmap, KTD20XX_IGRN1, &value);
+	len +=3D sprintf(buf + len, "%d", value);
+	len +=3D sprintf(buf + len, " ");
+
+	regmap_read(chip->regmap, KTD20XX_IBLU1, &value);
+	len +=3D sprintf(buf + len, "%d", value);
+	mutex_unlock(&chip->lock);
+
+	buf[len++] =3D '\n';
+	return len;
+}
+static ssize_t current_color1_store(struct device *dev,
+		struct device_attribute *a,
+		const char *buf, size_t size)
+{
+	struct i2c_client *client =3D to_i2c_client(dev);
+	struct ktd20xx *chip =3D i2c_get_clientdata(client);
+	unsigned int value[3];
+	int i;
+	ssize_t ret;
+
+	ret =3D sscanf(buf, "%u %u %u", &value[0], &value[1], &value[2]);
+	if (ret < 3) {
+		ret =3D -EINVAL;
+		goto err_out;
+	}
+
+	for (i =3D 0; i < 3; i++) {
+		if (value[i] > 194) {
+			ret =3D -EINVAL;
+			goto err_out;
+		}
+		if (value[i] < 0) {
+			ret =3D -EINVAL;
+			goto err_out;
+		}
+	}
+
+	mutex_lock(&chip->lock);
+	regmap_write(chip->regmap, KTD20XX_IRED1, value[0]);
+	regmap_write(chip->regmap, KTD20XX_IGRN1, value[1]);
+	regmap_write(chip->regmap, KTD20XX_IBLU1, value[2]);
+	mutex_unlock(&chip->lock);
+	return size;
+
+err_out:
+	return ret;
+}
+static DEVICE_ATTR_RW(current_color1);
+
+/*
+ * 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_attribut=
e *a,
+		char *buf)
+{
+	struct i2c_client *client =3D to_i2c_client(dev);
+	struct ktd20xx *chip =3D i2c_get_clientdata(client);
+	unsigned int value;
+
+	mutex_lock(&chip->lock);
+	regmap_field_read(chip->control_mode, &value);
+	mutex_unlock(&chip->lock);
+
+	if (value =3D=3D CONTROL_MODE_NIGHT)
+		return sprintf(buf, "%d\n", 1);
+	else
+		return sprintf(buf, "%d\n", 0);
+}
+
+static ssize_t nightmode_store(struct device *dev, struct device_attribu=
te *a,
+		const char *buf, size_t count)
+{
+	struct i2c_client *client =3D to_i2c_client(dev);
+	struct ktd20xx *chip =3D i2c_get_clientdata(client);
+	unsigned long nightmode;
+	int ret;
+
+	if (kstrtoul(buf, 10, &nightmode))
+		return -EINVAL;
+
+	if (nightmode > 1)
+		return -EINVAL;
+
+	mutex_lock(&chip->lock);
+	if (nightmode =3D=3D 1)
+		ret =3D regmap_field_write(chip->control_mode, CONTROL_MODE_NIGHT);
+	else
+		ret =3D regmap_field_write(chip->control_mode, CONTROL_MODE_NORMAL);
+	mutex_unlock(&chip->lock);
+
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+static DEVICE_ATTR_RW(nightmode);
+
+/*
+ * The chip also offers the option "Fade rate".
+ */
+static ssize_t faderate_show(struct device *dev, struct device_attribute=
 *a,
+		char *buf)
+{
+	struct i2c_client *client =3D to_i2c_client(dev);
+	struct ktd20xx *chip =3D i2c_get_clientdata(client);
+	unsigned int value;
+
+	mutex_lock(&chip->lock);
+	regmap_field_read(chip->faderate, &value);
+	mutex_unlock(&chip->lock);
+
+	return sprintf(buf, "%d\n", value);
+}
+
+static ssize_t faderate_store(struct device *dev, struct device_attribut=
e *a,
+		const char *buf, size_t count)
+{
+	struct i2c_client *client =3D to_i2c_client(dev);
+	struct ktd20xx *chip =3D i2c_get_clientdata(client);
+	unsigned long faderate;
+
+	if (kstrtoul(buf, 10, &faderate))
+		return -EINVAL;
+
+	if (faderate < 0)
+		return -EINVAL;
+
+	if (faderate > 7)
+		return -EINVAL;
+
+	mutex_lock(&chip->lock);
+	regmap_field_write(chip->faderate, faderate);
+	mutex_unlock(&chip->lock);
+
+	return count;
+}
+static DEVICE_ATTR_RW(faderate);
+
+static struct attribute *ktd20xx_led_controller_attrs[] =3D {
+	&dev_attr_current_color0.attr,
+	&dev_attr_current_color1.attr,
+	&dev_attr_nightmode.attr,
+	&dev_attr_faderate.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;
+	int ret;
+
+	chip =3D devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	mutex_init(&chip->lock);
+	chip->client =3D client;
+	chip->dev =3D &client->dev;
+	i2c_set_clientdata(client, chip);
+
+	chip->regmap =3D devm_regmap_init_i2c(client, &ktd20xx_regmap_config);
+	if (IS_ERR(chip->regmap)) {
+		ret =3D PTR_ERR(chip->regmap);
+		dev_err(&client->dev, "Failed to allocate register map: %d\n",
+			ret);
+		goto error;
+	}
+
+	chip->control_mode =3D devm_regmap_field_alloc(chip->dev, chip->regmap,
+			kt20xx_control_mode);
+	chip->faderate =3D devm_regmap_field_alloc(chip->dev, chip->regmap,
+			kt20xx_faderate);
+	chip->vendor =3D devm_regmap_field_alloc(chip->dev, chip->regmap,
+			kt20xx_vendor);
+	chip->chip_id =3D devm_regmap_field_alloc(chip->dev, chip->regmap,
+			kt20xx_chip_id);
+	chip->chip_rev =3D devm_regmap_field_alloc(chip->dev, chip->regmap,
+			kt20xx_chip_rev);
+
+	regmap_field_write(chip->control_mode, CONTROL_MODE_RESET);
+	ret =3D regmap_field_read(chip->vendor, &vendor);
+	if (ret) {
+		dev_err(&client->dev, "Failed to read vendor: %d\n", ret);
+		goto error;
+	}
+
+	ret =3D regmap_field_read(chip->chip_id, &chip_id);
+	if (ret) {
+		dev_err(&client->dev, "Failed to read chip id: %d\n", ret);
+		goto error;
+	}
+
+	ret =3D regmap_field_read(chip->chip_rev, &chip_rev);
+	if (ret) {
+		dev_err(&client->dev, "Failed to read chip rev: %d\n", ret);
+		goto error;
+	}
+
+	dev_info(&client->dev, "vendor: 0x%02x chip-id: 0x%02x chip-rev: 0x%02x=
\n",
+			vendor, chip_id, chip_rev);
+
+	regmap_field_write(chip->control_mode, CONTROL_MODE_NORMAL);
+
+	if (devm_device_add_groups(chip->dev, ktd20xx_led_controller_groups))
+		dev_warn(&client->dev, "Could not add attribute group!\n");
+
+	ret =3D ktd20xx_hwinit(chip);
+	if (ret)
+		goto error;
+
+	ret =3D ktd20xx_probe_dt(chip);
+	if (ret)
+		goto error;
+
+	return 0;
+
+error:
+	mutex_destroy(&chip->lock);
+	return ret;
+}
+
+static int ktd20xx_remove(struct i2c_client *client)
+{
+	struct ktd20xx *chip =3D i2c_get_clientdata(client);
+
+	mutex_lock(&chip->lock);
+	regmap_field_write(chip->control_mode, CONTROL_MODE_OFF);
+	mutex_unlock(&chip->lock);
+
+	mutex_destroy(&chip->lock);
+
+	return 0;
+}
+
+static const struct i2c_device_id ktd20xx_id[] =3D {
+	{ "ktd20xx", 0 },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, ktd20xx_id);
+
+static const struct of_device_id of_ktd20xx_leds_match[] =3D {
+	{ .compatible =3D "kinetic,ktd20xx", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, of_ktd20xx_leds_match);
+
+static struct i2c_driver ktd20xx_driver =3D {
+	.driver =3D {
+		.name	=3D "ktd20xx",
+		.of_match_table =3D of_ktd20xx_leds_match,
+	},
+	.probe		=3D ktd20xx_probe,
+	.remove		=3D ktd20xx_remove,
+	.id_table	=3D 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");
--=20
2.20.1