| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Backlight driver for the Kinetic KTZ8866 |
| * |
| * Copyright (C) 2022, 2023 Jianhua Lu <lujianhua000@gmail.com> |
| */ |
| |
| #include <linux/backlight.h> |
| #include <linux/err.h> |
| #include <linux/gpio/consumer.h> |
| #include <linux/i2c.h> |
| #include <linux/module.h> |
| #include <linux/of.h> |
| #include <linux/regmap.h> |
| |
| #define DEFAULT_BRIGHTNESS 1500 |
| #define MAX_BRIGHTNESS 2047 |
| #define REG_MAX 0x15 |
| |
| /* reg */ |
| #define DEVICE_ID 0x01 |
| #define BL_CFG1 0x02 |
| #define BL_CFG2 0x03 |
| #define BL_BRT_LSB 0x04 |
| #define BL_BRT_MSB 0x05 |
| #define BL_EN 0x08 |
| #define LCD_BIAS_CFG1 0x09 |
| #define LCD_BIAS_CFG2 0x0A |
| #define LCD_BIAS_CFG3 0x0B |
| #define LCD_BOOST_CFG 0x0C |
| #define OUTP_CFG 0x0D |
| #define OUTN_CFG 0x0E |
| #define FLAG 0x0F |
| #define BL_OPTION1 0x10 |
| #define BL_OPTION2 0x11 |
| #define PWM2DIG_LSBs 0x12 |
| #define PWM2DIG_MSBs 0x13 |
| #define BL_DIMMING 0x14 |
| #define PWM_RAMP_TIME 0x15 |
| |
| /* definition */ |
| #define BL_EN_BIT BIT(6) |
| #define LCD_BIAS_EN 0x9F |
| #define PWM_HYST 0x5 |
| |
| struct ktz8866 { |
| struct i2c_client *client; |
| struct regmap *regmap; |
| bool led_on; |
| struct gpio_desc *enable_gpio; |
| }; |
| |
| static const struct regmap_config ktz8866_regmap_config = { |
| .reg_bits = 8, |
| .val_bits = 8, |
| .max_register = REG_MAX, |
| }; |
| |
| static int ktz8866_write(struct ktz8866 *ktz, unsigned int reg, |
| unsigned int val) |
| { |
| return regmap_write(ktz->regmap, reg, val); |
| } |
| |
| static int ktz8866_update_bits(struct ktz8866 *ktz, unsigned int reg, |
| unsigned int mask, unsigned int val) |
| { |
| return regmap_update_bits(ktz->regmap, reg, mask, val); |
| } |
| |
| static int ktz8866_backlight_update_status(struct backlight_device *backlight_dev) |
| { |
| struct ktz8866 *ktz = bl_get_data(backlight_dev); |
| unsigned int brightness = backlight_get_brightness(backlight_dev); |
| |
| if (!ktz->led_on && brightness > 0) { |
| ktz8866_update_bits(ktz, BL_EN, BL_EN_BIT, BL_EN_BIT); |
| ktz->led_on = true; |
| } else if (brightness == 0) { |
| ktz8866_update_bits(ktz, BL_EN, BL_EN_BIT, 0); |
| ktz->led_on = false; |
| } |
| |
| /* Set brightness */ |
| ktz8866_write(ktz, BL_BRT_LSB, brightness & 0x7); |
| ktz8866_write(ktz, BL_BRT_MSB, (brightness >> 3) & 0xFF); |
| |
| return 0; |
| } |
| |
| static const struct backlight_ops ktz8866_backlight_ops = { |
| .options = BL_CORE_SUSPENDRESUME, |
| .update_status = ktz8866_backlight_update_status, |
| }; |
| |
| static void ktz8866_init(struct ktz8866 *ktz) |
| { |
| unsigned int val = 0; |
| |
| if (of_property_read_u32(ktz->client->dev.of_node, "current-num-sinks", &val)) |
| ktz8866_write(ktz, BL_EN, BIT(val) - 1); |
| else |
| /* Enable all 6 current sinks if the number of current sinks isn't specified. */ |
| ktz8866_write(ktz, BL_EN, BIT(6) - 1); |
| |
| if (of_property_read_u32(ktz->client->dev.of_node, "kinetic,current-ramp-delay-ms", &val)) { |
| if (val <= 128) |
| ktz8866_write(ktz, BL_CFG2, BIT(7) | (ilog2(val) << 3) | PWM_HYST); |
| else |
| ktz8866_write(ktz, BL_CFG2, BIT(7) | ((5 + val / 64) << 3) | PWM_HYST); |
| } |
| |
| if (of_property_read_u32(ktz->client->dev.of_node, "kinetic,led-enable-ramp-delay-ms", &val)) { |
| if (val == 0) |
| ktz8866_write(ktz, BL_DIMMING, 0); |
| else { |
| unsigned int ramp_off_time = ilog2(val) + 1; |
| unsigned int ramp_on_time = ramp_off_time << 4; |
| ktz8866_write(ktz, BL_DIMMING, ramp_on_time | ramp_off_time); |
| } |
| } |
| |
| if (of_property_read_bool(ktz->client->dev.of_node, "kinetic,enable-lcd-bias")) |
| ktz8866_write(ktz, LCD_BIAS_CFG1, LCD_BIAS_EN); |
| } |
| |
| static int ktz8866_probe(struct i2c_client *client) |
| { |
| struct backlight_device *backlight_dev; |
| struct backlight_properties props; |
| struct ktz8866 *ktz; |
| int ret = 0; |
| |
| ktz = devm_kzalloc(&client->dev, sizeof(*ktz), GFP_KERNEL); |
| if (!ktz) |
| return -ENOMEM; |
| |
| ktz->client = client; |
| ktz->regmap = devm_regmap_init_i2c(client, &ktz8866_regmap_config); |
| if (IS_ERR(ktz->regmap)) |
| return dev_err_probe(&client->dev, PTR_ERR(ktz->regmap), "failed to init regmap\n"); |
| |
| ret = devm_regulator_get_enable(&client->dev, "vddpos"); |
| if (ret) |
| return dev_err_probe(&client->dev, ret, "get regulator vddpos failed\n"); |
| ret = devm_regulator_get_enable(&client->dev, "vddneg"); |
| if (ret) |
| return dev_err_probe(&client->dev, ret, "get regulator vddneg failed\n"); |
| |
| ktz->enable_gpio = devm_gpiod_get_optional(&client->dev, "enable", GPIOD_OUT_HIGH); |
| if (IS_ERR(ktz->enable_gpio)) |
| return PTR_ERR(ktz->enable_gpio); |
| |
| memset(&props, 0, sizeof(props)); |
| props.type = BACKLIGHT_RAW; |
| props.max_brightness = MAX_BRIGHTNESS; |
| props.brightness = DEFAULT_BRIGHTNESS; |
| props.scale = BACKLIGHT_SCALE_LINEAR; |
| |
| backlight_dev = devm_backlight_device_register(&client->dev, "ktz8866-backlight", |
| &client->dev, ktz, &ktz8866_backlight_ops, &props); |
| if (IS_ERR(backlight_dev)) |
| return dev_err_probe(&client->dev, PTR_ERR(backlight_dev), |
| "failed to register backlight device\n"); |
| |
| ktz8866_init(ktz); |
| |
| i2c_set_clientdata(client, backlight_dev); |
| backlight_update_status(backlight_dev); |
| |
| return 0; |
| } |
| |
| static void ktz8866_remove(struct i2c_client *client) |
| { |
| struct backlight_device *backlight_dev = i2c_get_clientdata(client); |
| backlight_dev->props.brightness = 0; |
| backlight_update_status(backlight_dev); |
| } |
| |
| static const struct i2c_device_id ktz8866_ids[] = { |
| { "ktz8866", 0 }, |
| {}, |
| }; |
| MODULE_DEVICE_TABLE(i2c, ktz8866_ids); |
| |
| static const struct of_device_id ktz8866_match_table[] = { |
| { |
| .compatible = "kinetic,ktz8866", |
| }, |
| {}, |
| }; |
| |
| static struct i2c_driver ktz8866_driver = { |
| .driver = { |
| .name = "ktz8866", |
| .of_match_table = ktz8866_match_table, |
| }, |
| .probe_new = ktz8866_probe, |
| .remove = ktz8866_remove, |
| .id_table = ktz8866_ids, |
| }; |
| |
| module_i2c_driver(ktz8866_driver); |
| |
| MODULE_DESCRIPTION("Kinetic KTZ8866 Backlight Driver"); |
| MODULE_AUTHOR("Jianhua Lu <lujianhua000@gmail.com>"); |
| MODULE_LICENSE("GPL"); |