On Tue, Dec 20, 2022, Jianhua Lu <lujianhua000@xxxxxxxxx> wrote: > > Add support for Kinetic KTZ8866 backlight, which is used in > Xiaomi tablet, Mi Pad 5 series. This driver lightly based on > downstream implementation [1]. > [1] https://github.com/MiCode/Xiaomi_Kernel_OpenSource/blob/elish-r-oss/drivers/video/backlight/ktz8866.c > > Signed-off-by: Jianhua Lu <lujianhua000@xxxxxxxxx> > --- > drivers/video/backlight/Kconfig | 8 ++ > drivers/video/backlight/Makefile | 1 + > drivers/video/backlight/ktz8866.c | 173 ++++++++++++++++++++++++++++++ > drivers/video/backlight/ktz8866.h | 31 ++++++ > 4 files changed, 213 insertions(+) > create mode 100644 drivers/video/backlight/ktz8866.c > create mode 100644 drivers/video/backlight/ktz8866.h > > diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig > index 936ba1e4d35e..2845fd7e33ad 100644 > --- a/drivers/video/backlight/Kconfig > +++ b/drivers/video/backlight/Kconfig > @@ -190,6 +190,14 @@ config BACKLIGHT_KTD253 > which is a 1-wire GPIO-controlled backlight found in some mobile > phones. > > +config BACKLIGHT_KTZ8866 > + tristate "Backlight Driver for Kinetic KTZ8866" > + depends on I2C > + select REGMAP_I2C > + help > + Say Y to enabled the backlight driver for the Kinetic KTZ8866 > + found in Xiaomi Mi Pad 5 series. > + > config BACKLIGHT_LM3533 > tristate "Backlight Driver for LM3533" > depends on MFD_LM3533 > diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile > index e815f3f1deff..f70a819c304c 100644 > --- a/drivers/video/backlight/Makefile > +++ b/drivers/video/backlight/Makefile > @@ -36,6 +36,7 @@ obj-$(CONFIG_BACKLIGHT_HP680) += hp680_bl.o > obj-$(CONFIG_BACKLIGHT_HP700) += jornada720_bl.o > obj-$(CONFIG_BACKLIGHT_IPAQ_MICRO) += ipaq_micro_bl.o > obj-$(CONFIG_BACKLIGHT_KTD253) += ktd253-backlight.o > +obj-$(CONFIG_BACKLIGHT_KTZ8866) += ktz8866.o > obj-$(CONFIG_BACKLIGHT_LM3533) += lm3533_bl.o > obj-$(CONFIG_BACKLIGHT_LM3630A) += lm3630a_bl.o > obj-$(CONFIG_BACKLIGHT_LM3639) += lm3639_bl.o > diff --git a/drivers/video/backlight/ktz8866.c b/drivers/video/backlight/ktz8866.c > new file mode 100644 > index 000000000000..1eaf72d9116b > --- /dev/null > +++ b/drivers/video/backlight/ktz8866.c > @@ -0,0 +1,173 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Backlight driver for the Kinetic KTZ8866 > + * > + * Copyright (C) Jianhua Lu <lujianhua000@xxxxxxxxx> Please add '2022'. > + */ > + > +#include <linux/backlight.h> > +#include <linux/delay.h> > +#include <linux/err.h> > +#include <linux/of.h> > +#include <linux/i2c.h> Please sort these headers alphabetically. > +#include <linux/module.h> > +#include <linux/regmap.h> > +#include "ktz8866.h" > + > +#define DEF_BRIGHTNESS 1500 What is 'DEF'? Please use more meaningful name. > +#define MAX_BRIGHTNESS 2047 > +#define REG_MAX 0x15 > + > +/* Helper */ Remove this meaningless comment line. > +#define low_3_bit(x) ((x)&0x7) > +#define high_8_bit(x) ((x >> 3) & 0xFF) > + > +struct ktz8866 { > + struct i2c_client *client; > + struct regmap *regmap; > + bool state; > +}; > + > +enum { > + LED_OFF, > + LED_ON, > +}; > + > +static const struct regmap_config ktz8866_regmap_config = { > + .reg_bits = 8, > + .val_bits = 8, > + .max_register = REG_MAX, > +}; > + > +int ktz8866_write(struct ktz8866 *ktz, unsigned int reg, unsigned int val) Add 'static' here, unless you have a reason. > +{ > + 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) Hmm, use 1 line not 2 lines, if there is no reason. > +{ > + struct ktz8866 *ktz = bl_get_data(backlight_dev); > + unsigned int brightness = backlight_get_brightness(backlight_dev); > + > + if (!ktz->state && brightness > 0) { > + ktz8866_update_bits(ktz, BL_EN, BIT(6), BIT(6)); Please use definitions. > + ktz->state = LED_ON; > + } else if (brightness == 0) { > + ktz8866_update_bits(ktz, BL_EN, BIT(6), 0); > + ktz->state = LED_OFF; > + msleep(10); > + } > + > + /* Set brightness */ > + ktz8866_write(ktz, BL_BRT_LSB, low_3_bit(brightness)); > + ktz8866_write(ktz, BL_BRT_MSB, high_8_bit(brightness)); > + > + 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) > +{ > + /* Enable 1~5 current sinks */ > + ktz8866_write(ktz, BL_EN, 0x1F); > + /* Backlight OVP 26.4V */ > + ktz8866_write(ktz, BL_CFG1, 0x33); > + /* LED ramping time 128ms */ > + ktz8866_write(ktz, BL_CFG2, 0xBD); > + /* LED on/off ramping time 1ms */ > + ktz8866_write(ktz, BL_DIMMING, 0x11); > + /* Enable OUTP and OUTN via pin ENP and ENN */ > + ktz8866_write(ktz, LCD_BIAS_CFG1, 0x9F); > + /* Backlight Full-scale LED Current 30.0mA */ > + ktz8866_write(ktz, FULL_SCALE_CURRENT, 0xF9); Don't use hardcoding. Please add definitions for bits, and use these definitions. > +} > + > +static int ktz8866_probe(struct i2c_client *client, > + const struct i2c_device_id *id) > +{ > + struct backlight_device *backlight_dev; > + struct backlight_properties props; > + struct ktz8866 *ktz; > + > + 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)) { > + dev_err(&client->dev, "failed to init regmap\n"); > + return PTR_ERR(ktz->regmap); > + } > + > + memset(&props, 0, sizeof(props)); > + props.type = BACKLIGHT_RAW; > + props.max_brightness = MAX_BRIGHTNESS; > + props.brightness = > + clamp_t(unsigned int, DEF_BRIGHTNESS, 0, props.max_brightness); > + > + backlight_dev = devm_backlight_device_register( > + &client->dev, "ktz8866-backlight", &client->dev, ktz, > + &ktz8866_backlight_ops, &props); > + > + if (IS_ERR(backlight_dev)) { > + dev_err(&client->dev, "failed to register backlight device\n"); > + return PTR_ERR(backlight_dev); > + } > + > + 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@xxxxxxxxx>"); > +MODULE_LICENSE("GPL"); > diff --git a/drivers/video/backlight/ktz8866.h b/drivers/video/backlight/ktz8866.h > new file mode 100644 > index 000000000000..b2a606288a7e > --- /dev/null > +++ b/drivers/video/backlight/ktz8866.h > @@ -0,0 +1,31 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > +/* > + * Register definitions for Kinetic KTZ8866 backlight > + * > + * Copyright (C) Jianhua Lu <lujianhua000@xxxxxxxxx> Please add '2022'. Best regards, Jingoo Han > + */ > + > +#ifndef KTZ8866_H > +#define KTZ8866_H > + > +#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 FULL_SCALE_CURRENT 0x15 > + > +#endif /* KTZ8866_H */ > -- > 2.38.2 >
