--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2022 Svyatoslav Ryhel <clamor95@gmail.com>
+ */
+
+#define LOG_CATEGORY UCLASS_PANEL_BACKLIGHT
+
+#include <backlight.h>
+#include <common.h>
+#include <dm.h>
+#include <i2c.h>
+#include <log.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <asm/gpio.h>
+
+#define LM3533_BL_MIN_BRIGHTNESS 0x02
+#define LM3533_BL_MAX_BRIGHTNESS 0xFF
+
+#define LM3533_SINK_OUTPUT_CONFIG_1 0x10
+#define LM3533_CONTROL_BANK_A_PWM 0x14
+#define LM3533_CONTROL_BANK_AB_BRIGHTNESS 0x1A
+#define LM3533_CONTROL_BANK_A_FULLSCALE_CURRENT 0x1F
+#define LM3533_CONTROL_BANK_ENABLE 0x27
+#define LM3533_OVP_FREQUENCY_PWM_POLARITY 0x2C
+#define LM3533_BRIGHTNESS_REGISTER_A 0x40
+
+struct lm3533_backlight_priv {
+ struct gpio_desc enable_gpio;
+ u32 def_bl_lvl;
+};
+
+static int lm3533_backlight_enable(struct udevice *dev)
+{
+ struct lm3533_backlight_priv *priv = dev_get_priv(dev);
+ int ret;
+
+ dm_gpio_set_value(&priv->enable_gpio, 1);
+ mdelay(5);
+
+ /* HVLED 1 & 2 are controlled by Bank A */
+ ret = dm_i2c_reg_write(dev, LM3533_SINK_OUTPUT_CONFIG_1, 0x00);
+ if (ret)
+ return ret;
+
+ /* PWM input is disabled for CABC */
+ ret = dm_i2c_reg_write(dev, LM3533_CONTROL_BANK_A_PWM, 0x00);
+ if (ret)
+ return ret;
+
+ /* Linear & Control Bank A is configured for register Current control */
+ ret = dm_i2c_reg_write(dev, LM3533_CONTROL_BANK_AB_BRIGHTNESS, 0x02);
+ if (ret)
+ return ret;
+
+ /* Full-Scale Current (20.2mA) */
+ ret = dm_i2c_reg_write(dev, LM3533_CONTROL_BANK_A_FULLSCALE_CURRENT, 0x13);
+ if (ret)
+ return ret;
+
+ /* Control Bank A is enable */
+ ret = dm_i2c_reg_write(dev, LM3533_CONTROL_BANK_ENABLE, 0x01);
+ if (ret)
+ return ret;
+
+ ret = dm_i2c_reg_write(dev, LM3533_OVP_FREQUENCY_PWM_POLARITY, 0x0A);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int lm3533_backlight_set_brightness(struct udevice *dev, int percent)
+{
+ struct lm3533_backlight_priv *priv = dev_get_priv(dev);
+ int ret;
+
+ if (percent == BACKLIGHT_DEFAULT)
+ percent = priv->def_bl_lvl;
+
+ if (percent < LM3533_BL_MIN_BRIGHTNESS)
+ percent = LM3533_BL_MIN_BRIGHTNESS;
+
+ if (percent > LM3533_BL_MAX_BRIGHTNESS)
+ percent = LM3533_BL_MAX_BRIGHTNESS;
+
+ /* Set brightness level */
+ ret = dm_i2c_reg_write(dev, LM3533_BRIGHTNESS_REGISTER_A,
+ percent);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int lm3533_backlight_probe(struct udevice *dev)
+{
+ struct lm3533_backlight_priv *priv = dev_get_priv(dev);
+ int ret;
+
+ if (device_get_uclass_id(dev->parent) != UCLASS_I2C)
+ return -EPROTONOSUPPORT;
+
+ ret = gpio_request_by_name(dev, "enable-gpios", 0,
+ &priv->enable_gpio, GPIOD_IS_OUT);
+ if (ret) {
+ log_err("Could not decode enable-gpios (%d)\n", ret);
+ return ret;
+ }
+
+ priv->def_bl_lvl = dev_read_u32_default(dev, "default-brightness-level",
+ LM3533_BL_MAX_BRIGHTNESS);
+
+ return 0;
+}
+
+static const struct backlight_ops lm3533_backlight_ops = {
+ .enable = lm3533_backlight_enable,
+ .set_brightness = lm3533_backlight_set_brightness,
+};
+
+static const struct udevice_id lm3533_backlight_ids[] = {
+ { .compatible = "ti,lm3533" },
+ { }
+};
+
+U_BOOT_DRIVER(lm3533_backlight) = {
+ .name = "lm3533_backlight",
+ .id = UCLASS_PANEL_BACKLIGHT,
+ .of_match = lm3533_backlight_ids,
+ .probe = lm3533_backlight_probe,
+ .ops = &lm3533_backlight_ops,
+ .priv_auto = sizeof(struct lm3533_backlight_priv),
+};