--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/version.h>
+
+/**
+ * Driver for SmartRG RGBW LED microcontroller.
+ * RGBW LED is connected to a Holtek HT45F0062 that is on the I2C bus.
+ *
+ */
+
+struct srg_led_ctrl;
+struct srg_led {
+ u8 index;
+ struct led_classdev led;
+ struct srg_led_ctrl *ctrl;
+};
+
+struct srg_led_ctrl {
+ struct mutex lock;
+ struct i2c_client *client;
+ struct srg_led channel[4];
+ u8 control[5];
+};
+
+static int
+srg_led_i2c_write(struct srg_led_ctrl *sysled_ctrl, u8 reg, u8 value)
+{
+ return i2c_smbus_write_byte_data(sysled_ctrl->client, reg, value);
+}
+
+/*
+ * MC LED Command: 0 = OFF, 1 = ON, 2 = Flash, 3 = Pulse, 4 = Blink
+ * */
+static int
+srg_led_control_sync(struct srg_led_ctrl *sysled_ctrl)
+{
+ int i, ret;
+
+ for (i = 1; i < 5; i++) {
+ ret = srg_led_i2c_write(sysled_ctrl, i, sysled_ctrl->control[i]);
+ if (ret)
+ break;
+ }
+ return ret;
+}
+
+/*
+ * This function overrides the led driver timer trigger to offload
+ * flashing to the micro-controller. The negative effect of this
+ * is the inability to configure the delay_on and delay_off periods.
+ *
+ * */
+static int
+srg_led_set_pulse(struct led_classdev *led_cdev,
+ unsigned long *delay_on,
+ unsigned long *delay_off)
+{
+ struct srg_led *sysled = container_of(led_cdev, struct srg_led, led);
+ struct srg_led_ctrl *sysled_ctrl = sysled->ctrl;
+ bool blinking = false, pulsing = false;
+ u8 cbyte;
+ int ret;
+
+ if (delay_on && delay_off && (*delay_on > 100) && (*delay_on <= 500)) {
+ pulsing = true;
+ *delay_on = 500;
+ *delay_off = 500;
+ } else if (delay_on && delay_off && (*delay_on >= 50) && (*delay_on <= 100)) {
+ blinking = true;
+ *delay_on = 50;
+ *delay_off = 50;
+ }
+
+ cbyte = pulsing ? 3 : blinking ? 2 : 0;
+ mutex_lock(&sysled_ctrl->lock);
+ ret = srg_led_i2c_write(sysled_ctrl, sysled->index + 4,
+ (blinking || pulsing) ? 255 : 0);
+ if (!ret) {
+ sysled_ctrl->control[sysled->index] = cbyte;
+ ret = srg_led_control_sync(sysled_ctrl);
+ }
+ mutex_unlock(&sysled_ctrl->lock);
+
+ return !cbyte;
+}
+
+static int
+srg_led_set_brightness(struct led_classdev *led_cdev,
+ enum led_brightness value)
+{
+ struct srg_led *sysled = container_of(led_cdev, struct srg_led, led);
+ struct srg_led_ctrl *sysled_ctrl = sysled->ctrl;
+ int ret;
+
+ mutex_lock(&sysled_ctrl->lock);
+ ret = srg_led_i2c_write(sysled_ctrl, sysled->index + 4, value);
+ if (!ret) {
+ sysled_ctrl->control[sysled->index] = !!value;
+ ret = srg_led_control_sync(sysled_ctrl);
+ }
+ mutex_unlock(&sysled_ctrl->lock);
+ return ret;
+}
+
+static int
+srg_led_init_led(struct srg_led_ctrl *sysled_ctrl, struct device_node *np)
+{
+ struct led_init_data init_data = {};
+ struct led_classdev *led_cdev;
+ struct srg_led *sysled;
+ int index, ret;
+
+ if (!np)
+ return -ENOENT;
+
+ ret = of_property_read_u32(np, "reg", &index);
+ if (ret) {
+ dev_err(&sysled_ctrl->client->dev,
+ "srg_led_init_led: no reg defined in np!\n");
+ return ret;
+ }
+
+ if (index < 1 || index > 4)
+ return -EINVAL;
+
+ sysled = &sysled_ctrl->channel[index - 1];
+ led_cdev = &sysled->led;
+
+ sysled->index = index;
+ sysled->ctrl = sysled_ctrl;
+
+ init_data.fwnode = of_fwnode_handle(np);
+
+ led_cdev->name = of_get_property(np, "label", NULL) ? : np->name;
+ led_cdev->brightness = LED_OFF;
+ led_cdev->max_brightness = LED_FULL;
+ led_cdev->brightness_set_blocking = srg_led_set_brightness;
+ led_cdev->blink_set = srg_led_set_pulse;
+
+ srg_led_i2c_write(sysled_ctrl, index + 4, 0);
+
+ ret = devm_led_classdev_register_ext(&sysled_ctrl->client->dev,
+ led_cdev, &init_data);
+ if (ret) {
+ dev_err(&sysled_ctrl->client->dev,
+ "srg_led_init_led: led register %s error ret %d!n",
+ led_cdev->name, ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int
+srg_led_probe(struct i2c_client *client, const struct i2c_device_id *id)
+{
+ struct device_node *np = client->dev.of_node, *child;
+ struct srg_led_ctrl *sysled_ctrl;
+
+ sysled_ctrl = devm_kzalloc(&client->dev, sizeof(*sysled_ctrl), GFP_KERNEL);
+ if (!sysled_ctrl)
+ return -ENOMEM;
+
+ sysled_ctrl->client = client;
+
+ mutex_init(&sysled_ctrl->lock);
+
+ i2c_set_clientdata(client, sysled_ctrl);
+
+ for_each_child_of_node(np, child) {
+ if (srg_led_init_led(sysled_ctrl, child))
+ continue;
+
+ msleep(5);
+ }
+
+ return srg_led_control_sync(sysled_ctrl);;
+}
+
+static void srg_led_disable(struct i2c_client *client)
+{
+ struct srg_led_ctrl *sysled_ctrl = i2c_get_clientdata(client);
+ int i;
+
+ for (i = 1; i < 10; i++)
+ srg_led_i2c_write(sysled_ctrl, i, 0);
+}
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5,16,0)
+static void
+#else
+static int
+#endif
+srg_led_remove(struct i2c_client *client)
+{
+ struct srg_led_ctrl *sysled_ctrl = i2c_get_clientdata(client);
+
+ srg_led_disable(client);
+ mutex_destroy(&sysled_ctrl->lock);
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5,16,0)
+ return 0;
+#endif
+}
+
+static const struct i2c_device_id srg_led_id[] = {
+ { "srg-sysled", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, srg_led_id);
+
+static const struct of_device_id of_srg_led_match[] = {
+ { .compatible = "srg,sysled", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, of_srg_led_match);
+
+static struct i2c_driver srg_sysled_driver = {
+ .driver = {
+ .name = "srg-sysled",
+ .of_match_table = of_srg_led_match,
+ },
+ .probe = srg_led_probe,
+ .remove = srg_led_remove,
+ .id_table = srg_led_id,
+};
+module_i2c_driver(srg_sysled_driver);
+
+MODULE_DESCRIPTION("SmartRG system LED driver");
+MODULE_AUTHOR("Shen Loh <shen.loh@adtran.com>");
+MODULE_AUTHOR("Daniel Golle <daniel@makrotopia.org>");
+MODULE_LICENSE("GPL v2");
--- /dev/null
+---
+ drivers/leds/Kconfig | 10 ++++++++++
+ drivers/leds/Makefile | 1 +
+ 2 files changed, 11 insertions(+)
+
+--- a/drivers/leds/Kconfig
++++ b/drivers/leds/Kconfig
+@@ -877,6 +877,16 @@ source "drivers/leds/blink/Kconfig"
+ comment "Flash and Torch LED drivers"
+ source "drivers/leds/flash/Kconfig"
+
++config LEDS_SMARTRG_LED
++ tristate "LED support for Adtran SmartRG"
++ depends on LEDS_CLASS && I2C && OF
++ help
++ This option enables support for the Adtran SmartRG platform
++ system LED driver.
++
++ To compile this driver as a module, choose M here: the module
++ will be called leds-smartrg-system.
++
+ comment "LED Triggers"
+ source "drivers/leds/trigger/Kconfig"
+
+--- a/drivers/leds/Makefile
++++ b/drivers/leds/Makefile
+@@ -77,6 +77,7 @@ obj-$(CONFIG_LEDS_PWM) += leds-pwm.o
+ obj-$(CONFIG_LEDS_REGULATOR) += leds-regulator.o
+ obj-$(CONFIG_LEDS_S3C24XX) += leds-s3c24xx.o
+ obj-$(CONFIG_LEDS_SC27XX_BLTC) += leds-sc27xx-bltc.o
++obj-$(CONFIG_LEDS_SMARTRG_LED) += leds-smartrg-system.o
+ obj-$(CONFIG_LEDS_SUNFIRE) += leds-sunfire.o
+ obj-$(CONFIG_LEDS_SYSCON) += leds-syscon.o
+ obj-$(CONFIG_LEDS_TCA6507) += leds-tca6507.o
--- /dev/null
+---
+ drivers/leds/Kconfig | 10 ++++++++++
+ drivers/leds/Makefile | 1 +
+ 2 files changed, 11 insertions(+)
+
+--- a/drivers/leds/Kconfig
++++ b/drivers/leds/Kconfig
+@@ -873,6 +873,16 @@ source "drivers/leds/flash/Kconfig"
+ comment "RGB LED drivers"
+ source "drivers/leds/rgb/Kconfig"
+
++config LEDS_SMARTRG_LED
++ tristate "LED support for Adtran SmartRG"
++ depends on LEDS_CLASS && I2C && OF
++ help
++ This option enables support for the Adtran SmartRG platform
++ system LED driver.
++
++ To compile this driver as a module, choose M here: the module
++ will be called leds-smartrg-system.
++
+ comment "LED Triggers"
+ source "drivers/leds/trigger/Kconfig"
+
+--- a/drivers/leds/Makefile
++++ b/drivers/leds/Makefile
+@@ -76,6 +76,7 @@ obj-$(CONFIG_LEDS_PWM) += leds-pwm.o
+ obj-$(CONFIG_LEDS_REGULATOR) += leds-regulator.o
+ obj-$(CONFIG_LEDS_S3C24XX) += leds-s3c24xx.o
+ obj-$(CONFIG_LEDS_SC27XX_BLTC) += leds-sc27xx-bltc.o
++obj-$(CONFIG_LEDS_SMARTRG_LED) += leds-smartrg-system.o
+ obj-$(CONFIG_LEDS_SUNFIRE) += leds-sunfire.o
+ obj-$(CONFIG_LEDS_SYSCON) += leds-syscon.o
+ obj-$(CONFIG_LEDS_TCA6507) += leds-tca6507.o