[v6,2/2] backlight: ktz8866: Add support for Kinetic KTZ8866 backlight
Commit Message
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.
Changes in v6:
- Correct devicetree property name.
MAINTAINERS | 6 +
drivers/video/backlight/Kconfig | 8 ++
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/ktz8866.c | 205 ++++++++++++++++++++++++++++++
4 files changed, 220 insertions(+)
create mode 100644 drivers/video/backlight/ktz8866.c
Comments
On 18/01/2023 14:10, 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.
>
> Changes in v6:
> - Correct devicetree property name.
>
> MAINTAINERS | 6 +
> drivers/video/backlight/Kconfig | 8 ++
> drivers/video/backlight/Makefile | 1 +
> drivers/video/backlight/ktz8866.c | 205 ++++++++++++++++++++++++++++++
> 4 files changed, 220 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..f7113ceb264a 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 enable 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..ca3ac349cd10
> --- /dev/null
> +++ b/drivers/video/backlight/ktz8866.c
> @@ -0,0 +1,205 @@
> +// 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);
Why 10 ms? Document magic values. Their need, reason behind.
> + }
> +
> + /* 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))
Here and in other places - not conforming to coding style. Missing space
before (.
Be sure you run checkpatch --strict and fix all relevant errors.
> + 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-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, "led-ramping-time-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, "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);
> +
Drop blank line
> + if (IS_ERR(ktz->regmap)) {
> + dev_err(&client->dev, "failed to init regmap\n");
dev_err_probe
> + 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);
> +
Drop blank line
> + if (IS_ERR(backlight_dev)) {
> + dev_err(&client->dev, "failed to register backlight device\n");
dev_err_probe
> + 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");
Best regards,
Krzysztof
On Wed, Jan 18, 2023 at 02:39:15PM +0100, Krzysztof Kozlowski wrote:
> On 18/01/2023 14:10, 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.
> >
> > Changes in v6:
> > - Correct devicetree property name.
> >
> > MAINTAINERS | 6 +
> > drivers/video/backlight/Kconfig | 8 ++
> > drivers/video/backlight/Makefile | 1 +
> > drivers/video/backlight/ktz8866.c | 205 ++++++++++++++++++++++++++++++
> > 4 files changed, 220 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..f7113ceb264a 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 enable 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..ca3ac349cd10
> > --- /dev/null
> > +++ b/drivers/video/backlight/ktz8866.c
> > @@ -0,0 +1,205 @@
> > +// 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);
>
> Why 10 ms? Document magic values. Their need, reason behind.
>
> > + }
> > +
> > + /* 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))
>
> Here and in other places - not conforming to coding style. Missing space
> before (.
>
> Be sure you run checkpatch --strict and fix all relevant errors.
>
> > + 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-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, "led-ramping-time-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, "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);
> > +
>
> Drop blank line
>
> > + if (IS_ERR(ktz->regmap)) {
> > + dev_err(&client->dev, "failed to init regmap\n");
>
> dev_err_probe
>
> > + 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);
> > +
>
> Drop blank line
>
> > + if (IS_ERR(backlight_dev)) {
> > + dev_err(&client->dev, "failed to register backlight device\n");
>
> dev_err_probe
>
> > + 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");
>
> Best regards,
> Krzysztof
>
I will send new version patches, thanks.
Hi Jianhua,
I love your patch! Perhaps something to improve:
[auto build test WARNING on lee-backlight/for-backlight-next]
[also build test WARNING on lee-backlight/for-backlight-fixes lee-leds/for-leds-next pavel-leds/for-next linus/master v6.2-rc4 next-20230119]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Jianhua-Lu/backlight-ktz8866-Add-support-for-Kinetic-KTZ8866-backlight/20230118-214354
base: https://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight.git for-backlight-next
patch link: https://lore.kernel.org/r/20230118131002.15453-2-lujianhua000%40gmail.com
patch subject: [PATCH v6 2/2] backlight: ktz8866: Add support for Kinetic KTZ8866 backlight
config: parisc-randconfig-r031-20230119 (https://download.01.org/0day-ci/archive/20230120/202301200239.m4ZDprWz-lkp@intel.com/config)
compiler: hppa-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/b862510e8bf9eb34db9d71a372b9de05682cb8ad
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Jianhua-Lu/backlight-ktz8866-Add-support-for-Kinetic-KTZ8866-backlight/20230118-214354
git checkout b862510e8bf9eb34db9d71a372b9de05682cb8ad
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=parisc olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=parisc SHELL=/bin/bash drivers/video/backlight/
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
In file included from include/linux/bits.h:6,
from include/linux/ratelimit_types.h:5,
from include/linux/ratelimit.h:5,
from include/linux/dev_printk.h:16,
from include/linux/device.h:15,
from include/linux/backlight.h:12,
from drivers/video/backlight/ktz8866.c:8:
include/vdso/bits.h: In function 'ktz8866_init':
>> include/vdso/bits.h:7:40: warning: 'val' is used uninitialized [-Wuninitialized]
7 | #define BIT(nr) (UL(1) << (nr))
| ^~
drivers/video/backlight/ktz8866.c:98:22: note: 'val' was declared here
98 | unsigned int val;
| ^~~
vim +/val +7 include/vdso/bits.h
3945ff37d2f48d Vincenzo Frascino 2020-03-20 6
3945ff37d2f48d Vincenzo Frascino 2020-03-20 @7 #define BIT(nr) (UL(1) << (nr))
3945ff37d2f48d Vincenzo Frascino 2020-03-20 8
@@ -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
@@ -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 enable 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
@@ -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
new file mode 100644
@@ -0,0 +1,205 @@
+// 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-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, "led-ramping-time-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, "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");