dt: bindings: leds: Add NCP5623 multi-LED Controller

NCP5623 is DC-DC multi-LEDs driver with 94% peak

efficiency. NCP5623 has three PWMs which can be programmed up to 32 steps giving 32768 colors hue.

NCP5623 driver supports gradual dimming upward/downward with programmable delay steps. Also, the driver supports driving a single LED or multi-LED like RGB.

Signed-off-by Abdel Alkuor <[email protected]>

---
 .../sysfs-class-led-multicolor-driver-ncp5623 |  46 +++
 drivers/leds/rgb/Kconfig                      |  11 +
 drivers/leds/rgb/Makefile                     |   1 +
 drivers/leds/rgb/leds-ncp5623.c               | 320 ++++++++++++++++++
 4 files changed, 378 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-class-led-multicolor-driver-ncp5623
 create mode 100644 drivers/leds/rgb/leds-ncp5623.c

Documentation/ABI/testing/sysfs-class-led-multicolor-driver-ncp5623 new file +0 -0

new file mode 100644
index 000000000000..6b9f4849852b

Documentation/ABI/testing/sysfs-class-led-multicolor-driver-ncp5623 new file +15 -0

+Date:		Feb 2024
+KernelVersion:	6.8
+Contact:	Abdel Alkuor <[email protected]>
+Description:
+		Set gradual dimming direction which
+		can be either none, up, or down.
+		After setting the direction, brightness
+		can be set using one of 31 steps.
+
+		==== ======== ==== ======== ==== ========
+		Step ILED(mA) Step ILED(mA) Step ILED(mA)
+		0    0        11   1.38      22   3.06
+		1    0.92     12   1.45      23   3.45
+		2    0.95     13   1.53      24   3.94
+		3    0.98     14   1.62      25   4.60

Documentation/ABI/testing/sysfs-class-led-multicolor-driver-ncp5623 new file +20 -0

+Date:		Feb 2024
+KernelVersion:	6.8
+Contact:	Abdel Alkuor <[email protected]>
+Description:
+		Set gradual dimming time.
+
+		==== ======== ==== ======== ==== ========
+		Step Time(ms) Step Time(ms) Step Time(ms)
+		0     0       11   88       22   176
+		1     8       12   96       23   184
+		2     16      13   104      24   192
+		3     24      14   112      25   200
+		4     32      15   120      26   208
+		5     40      16   128      27   216
+		6     48      17   136      28   224
+		7     56      18   144      29   232
+		8     64      19   152      30   240
+		9     72      20   160      31   248
+		10    80      21   168
+		==== ======== ==== ======== ==== ========

drivers/leds/rgb/Kconfig +11 -0

index a6a21f564673..81ab6a526a78 100644
@@ -27,6 +27,17 @@ config LEDS_KTD202X
 	  To compile this driver as a module, choose M here: the module
 	  will be called leds-ktd202x.
 
+config LEDS_NCP5623
+	tristate "LED support for NCP5623"
+	depends on I2C
+	depends on OF
+	help
+	  This option enables support for ON semiconductor NCP5623
+	  Triple Output I2C Controlled RGB LED Driver.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called leds-ncp5623.
+
 config LEDS_PWM_MULTICOLOR
 	tristate "PWM driven multi-color LED Support"
 	depends on PWM

drivers/leds/rgb/Makefile +1 -0

index 243f31e4d70d..a501fd27f179 100644
@@ -2,6 +2,7 @@
 
 obj-$(CONFIG_LEDS_GROUP_MULTICOLOR)	+= leds-group-multicolor.o
 obj-$(CONFIG_LEDS_KTD202X)		+= leds-ktd202x.o
+obj-$(CONFIG_LEDS_NCP5623)		+= leds-ncp5623.o
 obj-$(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

drivers/leds/rgb/leds-ncp5623.c new file +0 -0

new file mode 100644
index 000000000000..e77dfca69ca3

drivers/leds/rgb/leds-ncp5623.c new file +20 -0

+ * Author: Abdel Alkuor <[email protected]>
+ * Datasheet: https://www.onsemi.com/pdf/datasheet/ncp5623-d.pdf
+ */
+
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/sysfs.h>
+#include <linux/workqueue.h>
+
+#include <linux/led-class-multicolor.h>
+
+#define NCP5623_REG(x)			((x) << 0x5)
+
+#define NCP5623_SHUTDOWN_REG		NCP5623_REG(0x0)
+#define NCP5623_ILED_REG		NCP5623_REG(0x1)
+#define NCP5623_PWM_REG(index)		NCP5623_REG(0x2 + (index))
+#define NCP5623_UPWARD_STEP_REG		NCP5623_REG(0x5)
+#define NCP5623_DOWNWARD_STEP_REG	NCP5623_REG(0x6)
+#define NCP5623_DIMMING_TIME_REG	NCP5623_REG(0x7)
+

drivers/leds/rgb/leds-ncp5623.c new file +13 -0

+	[NCP5623_DIR_UPWARD]   = "up",
+	[NCP5623_DIR_DOWNWARD] = "down",
+};
+
+struct ncp5623 {
+	struct i2c_client *client;
+	struct led_classdev_mc mc_dev;
+	struct mutex lock;
+
+	u8 direction;
+	u8 dim_step;
+	u8 old_brightness;
+	unsigned long delay;

drivers/leds/rgb/leds-ncp5623.c new file +7 -0

+	int diff = brightness - old_brightness;
+
+	if (dir == NCP5623_DIR_UPWARD)
+		return diff <= 1 ? NCP5623_MAX_BRIGHTNESS + diff : diff;
+
+	return diff >= -1 ? NCP5623_MAX_BRIGHTNESS - diff : -diff;
+

drivers/leds/rgb/leds-ncp5623.c new file +26 -0

+		ret = ncp5623_write(ncp->client,
+				    NCP5623_PWM_REG(mc_cdev->subled_info[i].channel),
+				    min(mc_cdev->subled_info[i].intensity,
+					NCP5623_MAX_BRIGHTNESS));
+		if (ret)
+			return ret;
+	}
+
+	switch (ncp->direction) {
+	case NCP5623_DIR_NONE:
+		reg = NCP5623_ILED_REG;
+		break;
+	case NCP5623_DIR_UPWARD:
+		reg = NCP5623_UPWARD_STEP_REG;
+		break;
+	case NCP5623_DIR_DOWNWARD:
+		reg = NCP5623_DOWNWARD_STEP_REG;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ret = ncp5623_write(ncp->client, reg, brightness);
+	if (ret)
+		return ret;
+

drivers/leds/rgb/leds-ncp5623.c new file +48 -0

+		ncp->delay *= ncp->dim_step * 8;
+		ncp->delay = msecs_to_jiffies(ncp->delay) + jiffies;
+	}
+
+	ncp->old_brightness = brightness;
+
+	return 0;
+}
+
+static ssize_t dim_step_store(struct device *dev,
+			      struct device_attribute *attr,
+			      const char *buf, size_t count)
+{
+	struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(dev_get_drvdata(dev));
+	struct ncp5623 *ncp = container_of(mc_cdev, struct ncp5623, mc_dev);
+	u8 value;
+	int ret;
+
+	ret = kstrtou8(buf, 0, &value);
+	if (ret)
+		return ret;
+
+	if (value > 0x1f)
+		return -EINVAL;
+
+	guard(mutex)(&ncp->lock);
+	ncp->dim_step = value;
+
+	return count;
+}
+
+static ssize_t dim_step_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(dev_get_drvdata(dev));
+	struct ncp5623 *ncp = container_of(mc_cdev, struct ncp5623, mc_dev);
+
+	guard(mutex)(&ncp->lock);
+
+	return sysfs_emit(buf, "%u\n", ncp->dim_step);
+}
+
+static ssize_t direction_store(struct device *dev,
+			       struct device_attribute *attr,
+			       const char *buf, size_t count)
+{
+	struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(dev_get_drvdata(dev));
+	struct ncp5623 *ncp = container_of(mc_cdev, struct ncp5623, mc_dev);

drivers/leds/rgb/leds-ncp5623.c new file +8 -0

+		return count;
+	default:
+		return -EINVAL;
+	}
+}
+
+static ssize_t direction_show(struct device *dev,
+			      struct device_attribute *attr, char *buf)

drivers/leds/rgb/leds-ncp5623.c new file +13 -0

+static DEVICE_ATTR_RW(direction);
+static DEVICE_ATTR_RW(dim_step);
+
+static struct attribute *ncp5623_led_attrs[] = {
+	&dev_attr_direction.attr,
+	&dev_attr_dim_step.attr,
+	NULL
+};
+
+static const struct attribute_group ncp5623_led_group = {
+	.attrs = ncp5623_led_attrs,
+};
+

drivers/leds/rgb/leds-ncp5623.c new file +69 -0

+	int ret;
+
+	ncp = devm_kzalloc(dev, sizeof(*ncp), GFP_KERNEL);
+	if (!ncp)
+		return -ENOMEM;
+
+	ncp->client = client;
+
+	mc_node = device_get_named_child_node(dev, "multi-led");
+	if (!mc_node)
+		return -EINVAL;
+
+	fwnode_for_each_child_node(mc_node, led_node)
+		count++;
+
+	subled_info = devm_kcalloc(dev, count, sizeof(*subled_info), GFP_KERNEL);
+	if (!subled_info) {
+		ret = -ENOMEM;
+		goto release_mc_node;
+	}
+
+	fwnode_for_each_available_child_node(mc_node, led_node) {
+		ret = fwnode_property_read_u32(led_node, "color", &color_index);
+		if (ret) {
+			fwnode_handle_put(led_node);
+			goto release_mc_node;
+		}
+
+		ret = fwnode_property_read_u32(led_node, "reg", &reg);
+		if (ret) {
+			fwnode_handle_put(led_node);
+			goto release_mc_node;
+		}
+
+		subled_info[ncp->mc_dev.num_colors].channel = reg;
+		subled_info[ncp->mc_dev.num_colors++].color_index = color_index;
+	}
+
+	init_data.fwnode = mc_node;
+
+	ncp->mc_dev.led_cdev.max_brightness = NCP5623_MAX_BRIGHTNESS;
+	ncp->mc_dev.subled_info = subled_info;
+	ncp->mc_dev.led_cdev.brightness_set_blocking = ncp5623_brightness_set;
+
+	mutex_init(&ncp->lock);
+	i2c_set_clientdata(client, ncp);
+
+	ret = devm_led_classdev_multicolor_register_ext(dev, &ncp->mc_dev, &init_data);
+	if (ret)
+		goto destroy_lock;
+
+	ret = sysfs_update_group(&ncp->mc_dev.led_cdev.dev->kobj, &ncp5623_led_group);
+	if (ret)
+		goto destroy_lock;
+
+	fwnode_handle_put(mc_node);
+
+	return 0;
+
+destroy_lock:
+	mutex_destroy(&ncp->lock);
+
+release_mc_node:
+	fwnode_handle_put(mc_node);
+
+	return ret;
+}
+
+static void ncp5623_remove(struct i2c_client *client)

drivers/leds/rgb/leds-ncp5623.c new file +23 -0

+}
+
+static const struct of_device_id ncp5623_id[] = {
+	{ .compatible = "onnn,ncp5623" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ncp5623_id);
+
+static struct i2c_driver ncp5623_i2c_driver = {
+	.driver	= {
+		.name = "ncp5623",
+		.of_match_table = ncp5623_id,
+	},
+	.probe = ncp5623_probe,
+	.remove = ncp5623_remove,
+	.shutdown = ncp5623_shutdown,
+};
+
+module_i2c_driver(ncp5623_i2c_driver);
+
+MODULE_AUTHOR("Abdel Alkuor <[email protected]>");
+MODULE_DESCRIPTION("NCP5623 Multi-LED driver");
+MODULE_LICENSE("GPL");

Signature · 1 line

2.34.1

On Sat, 03 Feb 2024, Abdel Alkuor wrote:

Quoted 1 line

+What: /sys/class/leds/<led>/dim_step

The step principle seems a bit arbitrary.

Why not provide the time directly?

dim_step_delay?

I already see documentation for risetime and falltime.

Perhaps that will omit the need for both direction and step?

Quoted 12 lines

Documentation/ABI/testing/sysfs-class-led-multicolor-driver-ncp5623 new file +12 -0

+Date:		Feb 2024
+KernelVersion:	6.8
+Contact:	Abdel Alkuor <[email protected]>
+Description:
+		Set gradual dimming time.
+
+		==== ======== ==== ======== ==== ========
+		Step Time(ms) Step Time(ms) Step Time(ms)
+		0     0       11   88       22   176
+		1     8       12   96       23   184
+		2     16      13   104      24   192
+		3     24      14   112      25   200

Documentation/ABI/testing/sysfs-class-led-multicolor-driver-ncp5623 line 46

Quoted 8 lines

Documentation/ABI/testing/sysfs-class-led-multicolor-driver-ncp5623 new file +8 -0

+		4     32      15   120      26   208
+		5     40      16   128      27   216
+		6     48      17   136      28   224
+		7     56      18   144      29   232
+		8     64      19   152      30   240
+		9     72      20   160      31   248
+		10    80      21   168
+		==== ======== ==== ======== ==== ========

Quoted 2 lines · Lee Jones

On Sat, 03 Feb 2024, Abdel Alkuor wrote:

Hi Lee,

Please check the inline comment. All other comments will be addressed in v2.

Quoted 10 lines

Quoted 1 line

+What: /sys/class/leds/<led>/dim_step

The step principle seems a bit arbitrary.

Why not provide the time directly?

dim_step_delay?

I already see documentation for risetime and falltime.

Quoted 2 lines

Perhaps that will omit the need for both direction and step?

I'm going to drop off both and use risetime and falltime. That being said, the documented risetime and falltime for lm3533 use steps instead of entering the time directly. This is my first time doing this, should I document risetime/falltime in sysfs-class-led-multicolor-driver-ncp5623? or should I update risetime/falltime in sysfs-class-led-driver-lm3533 to reflect risetime/falltime for ncp5623?

Quoted 12 lines

Quoted 12 lines

Documentation/ABI/testing/sysfs-class-led-multicolor-driver-ncp5623 new file +12 -0

+Date:		Feb 2024
+KernelVersion:	6.8
+Contact:	Abdel Alkuor <[email protected]>
+Description:
+		Set gradual dimming time.
+
+		==== ======== ==== ======== ==== ========
+		Step Time(ms) Step Time(ms) Step Time(ms)
+		0     0       11   88       22   176
+		1     8       12   96       23   184
+		2     16      13   104      24   192
+		3     24      14   112      25   200

Quoted 8 lines

Documentation/ABI/testing/sysfs-class-led-multicolor-driver-ncp5623 line 46

Quoted 8 lines

Documentation/ABI/testing/sysfs-class-led-multicolor-driver-ncp5623 new file +8 -0

+		4     32      15   120      26   208
+		5     40      16   128      27   216
+		6     48      17   136      28   224
+		7     56      18   144      29   232
+		8     64      19   152      30   240
+		9     72      20   160      31   248
+		10    80      21   168
+		==== ======== ==== ======== ==== ========

Thanks,
Abdel

 .../sysfs-class-led-multicolor-driver-ncp5623 |  46 +++
 drivers/leds/rgb/Kconfig                      |  11 +
 drivers/leds/rgb/Makefile                     |   1 +
 drivers/leds/rgb/leds-ncp5623.c               | 320 ++++++++++++++++++
 4 files changed, 378 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-class-led-multicolor-driver-ncp5623
 create mode 100644 drivers/leds/rgb/leds-ncp5623.c

Documentation/ABI/testing/sysfs-class-led-multicolor-driver-ncp5623 new file +0 -0

new file mode 100644
index 000000000000..6b9f4849852b

Quoted 1 line

+What: /sys/class/leds/<led>/dim_step

You are reinventing hardware_pattern trigger. NAK.

I suggest you add basic support first, then look at hardware pattern trigger and add that support in separate patch.

NCP5623 is DC-DC multi-LED controller which can be used for RGB illumination or backlight LCD display. NCP5623 provides 94% peak efficiency.

Signed-off-by Abdel Alkuor <[email protected]>

---
 .../bindings/leds/onnn,ncp5623.yaml           | 98 +++++++++++++++++++
 1 file changed, 98 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/onnn,ncp5623.yaml

Documentation/devicetree/bindings/leds/onnn,ncp5623.yaml new file +2 -0

new file mode 100644
index 000000000000..696bc7d8c8f9
@@ -0,0 +1,98 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2

Documentation/devicetree/bindings/leds/onnn,ncp5623.yaml new file +13 -0

+      - 0x38
+
+  multi-led:
+    type: object
+    $ref: leds-class-multicolor.yaml#
+    unevaluatedProperties: false
+
+    properties:
+      "#address-cells":
+        const: 1
+
+      "#size-cells":
+        const: 0