--- /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/of_gpio.h>
+#include <linux/gpio/consumer.h>
+
+/**
+ * Driver for the Ubiquiti RGB LED controller (LEDBAR).
+ * This Controller is based on a Holtek HT32F52241 and connected
+ * via I2C.
+ *
+ * - The Controller needs an enable signal set to high when
+ * performing a transaction. On the U6-LR, this is located
+ * at Pin 18 (R6902)
+ *
+ * - The Pin is also printed when calling the "usetled" function
+ * contained in the ubntapp bootloader application.
+ */
+
+#define UBNT_LEDBAR_MAX_BRIGHTNESS 0xff
+
+#define UBNT_LEDBAR_TRANSACTION_LENGTH 8
+#define UBNT_LEDBAR_TRANSACTION_SUCCESS 0xaa
+
+#define UBNT_LEDBAR_TRANSACTION_BLUE_IDX 2
+#define UBNT_LEDBAR_TRANSACTION_GREEN_IDX 3
+#define UBNT_LEDBAR_TRANSACTION_RED_IDX 4
+
+struct ubnt_ledbar {
+ struct mutex lock;
+ struct i2c_client *client;
+ struct led_classdev led_red;
+ struct led_classdev led_green;
+ struct led_classdev led_blue;
+ struct gpio_desc *enable_gpio;
+};
+
+static int ubnt_ledbar_perform_transaction(struct ubnt_ledbar *ledbar,
+ char *transaction)
+{
+ int ret;
+ int i;
+
+ for (i = 0; i < UBNT_LEDBAR_TRANSACTION_LENGTH; i++)
+ i2c_smbus_write_byte(ledbar->client, transaction[i]);
+
+ return i2c_smbus_read_byte(ledbar->client);
+}
+
+static int ubnt_ledbar_apply_state(struct ubnt_ledbar *ledbar)
+{
+ char setup_msg[UBNT_LEDBAR_TRANSACTION_LENGTH] = {0x40, 0x10, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x11};
+ char led_msg[UBNT_LEDBAR_TRANSACTION_LENGTH] = {0x40, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x01, 0x00};
+ char i2c_response;
+ int ret = 0;
+
+ mutex_lock(&ledbar->lock);
+
+ led_msg[UBNT_LEDBAR_TRANSACTION_BLUE_IDX] = ledbar->led_blue.brightness;
+ led_msg[UBNT_LEDBAR_TRANSACTION_GREEN_IDX] = ledbar->led_green.brightness;
+ led_msg[UBNT_LEDBAR_TRANSACTION_RED_IDX] = ledbar->led_red.brightness;
+
+ gpiod_set_raw_value(ledbar->enable_gpio, 1);
+
+ msleep(10);
+
+ i2c_response = ubnt_ledbar_perform_transaction(ledbar, setup_msg);
+ if (i2c_response != UBNT_LEDBAR_TRANSACTION_SUCCESS) {
+ dev_err(&ledbar->client->dev, "Error initializing LED transaction: %02x\n", ret);
+ ret = -EINVAL;
+ goto out_gpio;
+ }
+
+ i2c_response = ubnt_ledbar_perform_transaction(ledbar, led_msg);
+ if (i2c_response != UBNT_LEDBAR_TRANSACTION_SUCCESS) {
+ dev_err(&ledbar->client->dev, "Failed LED transaction: %02x\n", ret);
+ ret = -EINVAL;
+ goto out_gpio;
+ }
+
+ msleep(10);
+out_gpio:
+ gpiod_set_raw_value(ledbar->enable_gpio, 0);
+
+ mutex_unlock(&ledbar->lock);
+
+ return ret;
+}
+
+#define UBNT_LEDBAR_CONTROL_RGBS(name) \
+static int ubnt_ledbar_set_##name##_brightness(struct led_classdev *led_cdev,\
+ enum led_brightness value) \
+{ \
+ struct ubnt_ledbar *ledbar = \
+ container_of(led_cdev, struct ubnt_ledbar, led_##name); \
+ int ret; \
+ led_cdev->brightness = value; \
+ ret = ubnt_ledbar_apply_state(ledbar); \
+ return ret; \
+}
+
+UBNT_LEDBAR_CONTROL_RGBS(red);
+UBNT_LEDBAR_CONTROL_RGBS(green);
+UBNT_LEDBAR_CONTROL_RGBS(blue);
+
+
+static int ubnt_ledbar_init_led(struct device_node *np, struct ubnt_ledbar *ledbar,
+ struct led_classdev *led_cdev)
+{
+ struct led_init_data init_data = {};
+ int ret;
+
+ if (!np)
+ return 0;
+
+ init_data.fwnode = of_fwnode_handle(np);
+
+ led_cdev->max_brightness = UBNT_LEDBAR_MAX_BRIGHTNESS;
+
+ ret = devm_led_classdev_register_ext(&ledbar->client->dev, led_cdev,
+ &init_data);
+ if (ret)
+ dev_err(&ledbar->client->dev, "led register err: %d\n", ret);
+
+ return ret;
+}
+
+
+static int ubnt_ledbar_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct device_node *np = client->dev.of_node;
+ struct ubnt_ledbar *ledbar;
+ int ret;
+
+ ledbar = devm_kzalloc(&client->dev, sizeof(*ledbar), GFP_KERNEL);
+ if (!ledbar)
+ return -ENOMEM;
+
+ ledbar->enable_gpio = devm_gpiod_get(&client->dev, "enable", GPIOD_OUT_LOW);
+
+ if (IS_ERR(ledbar->enable_gpio)) {
+ ret = PTR_ERR(ledbar->enable_gpio);
+ dev_err(&client->dev, "Failed to get enable gpio: %d\n", ret);
+ return ret;
+ }
+
+ gpiod_direction_output(ledbar->enable_gpio, 0);
+
+ ledbar->client = client;
+
+ mutex_init(&ledbar->lock);
+
+ i2c_set_clientdata(client, ledbar);
+
+ ledbar->led_red.brightness_set_blocking = ubnt_ledbar_set_red_brightness;
+ ubnt_ledbar_init_led(of_get_child_by_name(np, "red"), ledbar, &ledbar->led_red);
+
+ ledbar->led_green.brightness_set_blocking = ubnt_ledbar_set_green_brightness;
+ ubnt_ledbar_init_led(of_get_child_by_name(np, "green"), ledbar, &ledbar->led_green);
+
+ ledbar->led_blue.brightness_set_blocking = ubnt_ledbar_set_blue_brightness;
+ ubnt_ledbar_init_led(of_get_child_by_name(np, "blue"), ledbar, &ledbar->led_blue);
+
+ return ubnt_ledbar_apply_state(ledbar);
+}
+
+static int ubnt_ledbar_remove(struct i2c_client *client)
+{
+ struct ubnt_ledbar *ledbar = i2c_get_clientdata(client);
+
+ mutex_destroy(&ledbar->lock);
+
+ return 0;
+}
+
+static const struct i2c_device_id ubnt_ledbar_id[] = {
+ { "ubnt-ledbar", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ubnt_ledbar_id);
+
+static const struct of_device_id of_ubnt_ledbar_match[] = {
+ { .compatible = "ubnt,ledbar", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, of_ubnt_ledbar_match);
+
+static struct i2c_driver ubnt_ledbar_driver = {
+ .driver = {
+ .name = "ubnt-ledbar",
+ .of_match_table = of_ubnt_ledbar_match,
+ },
+ .probe = ubnt_ledbar_probe,
+ .remove = ubnt_ledbar_remove,
+ .id_table = ubnt_ledbar_id,
+};
+module_i2c_driver(ubnt_ledbar_driver);
+
+MODULE_DESCRIPTION("Ubiquiti LEDBAR driver");
+MODULE_AUTHOR("David Bauer <mail@david-bauer.net>");
+MODULE_LICENSE("GPL v2");