diff options
Diffstat (limited to 'drivers/video/backlight/ktz8866.c')
| -rw-r--r-- | drivers/video/backlight/ktz8866.c | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/drivers/video/backlight/ktz8866.c b/drivers/video/backlight/ktz8866.c new file mode 100644 index 0000000000..9c980f2571 --- /dev/null +++ b/drivers/video/backlight/ktz8866.c @@ -0,0 +1,208 @@ +// 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 = 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"); |