| Message ID | 20230117154408.1882-2-lujianhua000@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v5,1/2] dt-bindings: leds: backlight: Add Kinetic KTZ8866 backlight | expand |
On Tue, Jan 17, 2023 at 11:44:08PM +0800, Jianhua Lu 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@gmail.com> > --- > Changes in v2: > - Add missing staitc modifier to ktz8866_write function. > > Changes in v3: > - Add 2022 to Copyright line. > - Sort headers. > - Remove meaningless comment. > - Use definitions instead of hardcoding. > - Add missing maintainer info. > > Changes in v4: > - Change 2022 to 2023. > - Remove useless macro and enum. > - Describe settings by devicetree. > - Move header file to C file. > Changes in v5: > - Change "2023" to "2022, 2023" in Copyright line. > - Set scale property for backlight. > > MAINTAINERS | 6 + > drivers/video/backlight/Kconfig | 8 ++ > drivers/video/backlight/Makefile | 1 + > drivers/video/backlight/ktz8866.c | 201 ++++++++++++++++++++++++++++++ > 4 files changed, 216 insertions(+) > create mode 100644 drivers/video/backlight/ktz8866.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 42fc47c6edfd..2084e74e1b58 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -11674,6 +11674,12 @@ M: John Hawley <warthog9@eaglescrag.net> > S: Maintained > F: tools/testing/ktest > > +KTZ8866 BACKLIGHT DRIVER > +M: Jianhua Lu <lujianhua000@gmail.com> > +S: Maintained > +F: Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml > +F: drivers/video/backlight/ktz8866.c > + > L3MDEV > M: David Ahern <dsahern@kernel.org> > L: netdev@vger.kernel.org > 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. s/enabled/enable/ (and sorry for spotting this one so late) > +++ b/drivers/video/backlight/ktz8866.c > @@ -0,0 +1,201 @@ > [...] > +static void ktz8866_init(struct ktz8866 *ktz) > +{ > + unsigned int val; > + > + 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 specifed. */ > + ktz8866_write(ktz, BL_EN, BIT(6) - 1); > + > + if(of_property_read_u32(ktz->client->dev.of_node, "current-ramping-time-us", &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); > + } This code is interpreting current-ramping-time-us as milliseconds rather than microseconds! I know I used microseconds in the example I proposed in the feedback for v4 DT bindings but "something like" means I am merely providing an example (mostly I was intending to show that the units should be included both in the property name *and* description). It is up to you whether you fix the mismatch by changing the DT bindings document to current-ramping-time-ms or change this code to accept values in microseconds. > + } > + > + if(of_property_read_u32(ktz->client->dev.of_node, "led-ramping-time-us", &val)) { > + 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); > + } Similarly, this code has not adopted the units specified in the bindings documentation. In this case 0 would map to 512us so if you decided to use milliseconds you will need to add comment in the description saying that 0 will map to 512us because the hardware cannot ramp faster than this! Daniel.
On Wed, Jan 18, 2023 at 12:08:01PM +0000, Daniel Thompson wrote: > On Tue, Jan 17, 2023 at 11:44:08PM +0800, Jianhua Lu 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@gmail.com> > > --- > > Changes in v2: > > - Add missing staitc modifier to ktz8866_write function. > > > > Changes in v3: > > - Add 2022 to Copyright line. > > - Sort headers. > > - Remove meaningless comment. > > - Use definitions instead of hardcoding. > > - Add missing maintainer info. > > > > Changes in v4: > > - Change 2022 to 2023. > > - Remove useless macro and enum. > > - Describe settings by devicetree. > > - Move header file to C file. > > Changes in v5: > > - Change "2023" to "2022, 2023" in Copyright line. > > - Set scale property for backlight. > > > > MAINTAINERS | 6 + > > drivers/video/backlight/Kconfig | 8 ++ > > drivers/video/backlight/Makefile | 1 + > > drivers/video/backlight/ktz8866.c | 201 ++++++++++++++++++++++++++++++ > > 4 files changed, 216 insertions(+) > > create mode 100644 drivers/video/backlight/ktz8866.c > > > > diff --git a/MAINTAINERS b/MAINTAINERS > > index 42fc47c6edfd..2084e74e1b58 100644 > > --- a/MAINTAINERS > > +++ b/MAINTAINERS > > @@ -11674,6 +11674,12 @@ M: John Hawley <warthog9@eaglescrag.net> > > S: Maintained > > F: tools/testing/ktest > > > > +KTZ8866 BACKLIGHT DRIVER > > +M: Jianhua Lu <lujianhua000@gmail.com> > > +S: Maintained > > +F: Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml > > +F: drivers/video/backlight/ktz8866.c > > + > > L3MDEV > > M: David Ahern <dsahern@kernel.org> > > L: netdev@vger.kernel.org > > 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. > > s/enabled/enable/ (and sorry for spotting this one so late) Get it. > > > > +++ b/drivers/video/backlight/ktz8866.c > > @@ -0,0 +1,201 @@ > > [...] > > +static void ktz8866_init(struct ktz8866 *ktz) > > +{ > > + unsigned int val; > > + > > + 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 specifed. */ > > + ktz8866_write(ktz, BL_EN, BIT(6) - 1); > > + > > + if(of_property_read_u32(ktz->client->dev.of_node, "current-ramping-time-us", &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); > > + } > > This code is interpreting current-ramping-time-us as milliseconds rather > than microseconds! > > I know I used microseconds in the example I proposed in the feedback for > v4 DT bindings but "something like" means I am merely providing an > example (mostly I was intending to show that the units should be > included both in the property name *and* description). > > It is up to you whether you fix the mismatch by changing the DT bindings > document to current-ramping-time-ms or change this code to accept > values in microseconds. This is my mistake, sorry. > > > > + } > > + > > + if(of_property_read_u32(ktz->client->dev.of_node, "led-ramping-time-us", &val)) { > > + 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); > > + } > > Similarly, this code has not adopted the units specified in the > bindings documentation. > > In this case 0 would map to 512us so if you decided to use milliseconds > you will need to add comment in the description saying that 0 will map > to 512us because the hardware cannot ramp faster than this! Get it, thank you very much. > > > Daniel.
diff --git a/MAINTAINERS b/MAINTAINERS index 42fc47c6edfd..2084e74e1b58 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11674,6 +11674,12 @@ M: John Hawley <warthog9@eaglescrag.net> S: Maintained F: tools/testing/ktest +KTZ8866 BACKLIGHT DRIVER +M: Jianhua Lu <lujianhua000@gmail.com> +S: Maintained +F: Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml +F: drivers/video/backlight/ktz8866.c + L3MDEV M: David Ahern <dsahern@kernel.org> L: netdev@vger.kernel.org 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..02d9be6e9df2 --- /dev/null +++ b/drivers/video/backlight/ktz8866.c @@ -0,0 +1,201 @@ +// 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/delay.h> +#include <linux/err.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; +}; + +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; + msleep(10); + } + + /* 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; + + 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 specifed. */ + ktz8866_write(ktz, BL_EN, BIT(6) - 1); + + if(of_property_read_u32(ktz->client->dev.of_node, "current-ramping-time-us", &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, "led-ramping-time-us", &val)) { + 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, "enable-lcd-bias")) + ktz8866_write(ktz, LCD_BIAS_CFG1, LCD_BIAS_EN); +} + +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 = 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)) { + 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@gmail.com>"); +MODULE_LICENSE("GPL");
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@gmail.com> --- Changes in v2: - Add missing staitc modifier to ktz8866_write function. Changes in v3: - Add 2022 to Copyright line. - Sort headers. - Remove meaningless comment. - Use definitions instead of hardcoding. - Add missing maintainer info. Changes in v4: - Change 2022 to 2023. - Remove useless macro and enum. - Describe settings by devicetree. - Move header file to C file. Changes in v5: - Change "2023" to "2022, 2023" in Copyright line. - Set scale property for backlight. MAINTAINERS | 6 + drivers/video/backlight/Kconfig | 8 ++ drivers/video/backlight/Makefile | 1 + drivers/video/backlight/ktz8866.c | 201 ++++++++++++++++++++++++++++++ 4 files changed, 216 insertions(+) create mode 100644 drivers/video/backlight/ktz8866.c