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 <[email protected]>
---
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.
MAINTAINERS | 6 +
drivers/video/backlight/Kconfig | 8 ++
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/ktz8866.c | 195 ++++++++++++++++++++++++++++++
4 files changed, 210 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 <[email protected]>
S: Maintained
F: tools/testing/ktest
+KTZ8866 BACKLIGHT DRIVER
+M: Jianhua Lu <[email protected]>
+S: Maintained
+F: Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml
+F: drivers/video/backlight/ktz8866.c
+
L3MDEV
M: David Ahern <[email protected]>
L: [email protected]
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..98916f92d069
--- /dev/null
+++ b/drivers/video/backlight/ktz8866.c
@@ -0,0 +1,195 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Backlight driver for the Kinetic KTZ8866
+ *
+ * Copyright (C) 2023 Jianhua Lu <[email protected]>
+ */
+
+#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", &val))
+ ktz8866_write(ktz, BL_CFG2, BIT(7) | (ilog2(val) << 3) | PWM_HYST);
+
+ if(of_property_read_u32(ktz->client->dev.of_node, "led-ramping-time", &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;
+
+ 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 <[email protected]>");
+MODULE_LICENSE("GPL");
--
2.38.2
Add Kinetic KTZ8866 backlight binding documentation.
Signed-off-by: Jianhua Lu <[email protected]>
---
Changes in v2:
- Remove "items" between "compatible" and "const: kinetic,ktz8866"
- Change "additionalProperties" to "unevaluatedProperties"
Changes in v3:
- Add Krzysztof's R-b
Changes in v4:
- Drop Krzysztof's R-b
- Add some new properties
.../leds/backlight/kinetic,ktz8866.yaml | 54 +++++++++++++++++++
1 file changed, 54 insertions(+)
create mode 100644 Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml
diff --git a/Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml b/Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml
new file mode 100644
index 000000000000..18571d69accb
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml
@@ -0,0 +1,54 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/backlight/kinetic,ktz8866.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Kinetic Technologies KTZ8866 backlight
+
+maintainers:
+ - Jianhua Lu <[email protected]>
+
+description: |
+ The Kinetic Technologies KTZ8866 is a high efficiency 6-sinks led backlight
+ with dual lcd bias power.
+ https://www.kinet-ic.com/ktz8866/
+
+allOf:
+ - $ref: common.yaml#
+
+properties:
+ compatible:
+ const: kinetic,ktz8866
+
+ current-num-sinks:
+ description: Number of LED current sinks.
+
+ current-ramping-time:
+ description: LED current ramping time.
+
+ led-ramping-time:
+ description: LED on/off ramping time.
+
+ enable-lcd-bias:
+ description: Set if we want to output bias power supply for LCD.
+ type: boolean
+
+required:
+ - compatible
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ backlight {
+ compatible = "kinetic,ktz8866";
+
+ pinctrl-names = "default";
+ pinctrl-0 = <&bl_en_default>;
+
+ current-num-sinks = <5>;
+ current-ramping-time = <128>;
+ led-ramping-time = <1>;
+ enable-lcd-bias;
+ };
--
2.38.2
On Tue, Jan 17, 2023 at 02:04:05PM +0000, Daniel Thompson wrote:
> On Tue, Jan 17, 2023 at 09:47:41PM +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 <[email protected]>
> > ---
> > 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.
> >
> > MAINTAINERS | 6 +
> > drivers/video/backlight/Kconfig | 8 ++
> > drivers/video/backlight/Makefile | 1 +
> > drivers/video/backlight/ktz8866.c | 195 ++++++++++++++++++++++++++++++
> > 4 files changed, 210 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 <[email protected]>
> > S: Maintained
> > F: tools/testing/ktest
> >
> > +KTZ8866 BACKLIGHT DRIVER
> > +M: Jianhua Lu <[email protected]>
> > +S: Maintained
> > +F: Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml
> > +F: drivers/video/backlight/ktz8866.c
> > +
> > L3MDEV
> > M: David Ahern <[email protected]>
> > L: [email protected]
> > 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..98916f92d069
> > --- /dev/null
> > +++ b/drivers/video/backlight/ktz8866.c
> > @@ -0,0 +1,195 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * Backlight driver for the Kinetic KTZ8866
> > + *
> > + * Copyright (C) 2023 Jianhua Lu <[email protected]>
>
> Shouldn't this be:
> Copyright (C) 2022, 2023 Jianhua Lu <[email protected]>
>
> > +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;
>
> There is still pending feedback from v3.
>
> | Please set the scale property correctly. "Unknown" is never correct for
> | new drivers.
Do you means backlight_properties.backlight_scale?
>
> Do not ignore feedback. You should either act on it or, if you disagree
> or need additional clarification then, reply on the mail thread.
>
>
> Daniel.
On Tue, Jan 17, 2023 at 02:22:04PM +0000, Daniel Thompson wrote:
> On Tue, Jan 17, 2023 at 09:47:42PM +0800, Jianhua Lu wrote:
> > Add Kinetic KTZ8866 backlight binding documentation.
> >
> > Signed-off-by: Jianhua Lu <[email protected]>
>
> Might be a good idea to take a look at this bit of the docs because
> the patchset is not in the right order (I.5):
> https://docs.kernel.org/devicetree/bindings/submitting-patches.html
Thanks, I will read it.
>
>
> > ---
> > Changes in v2:
> > - Remove "items" between "compatible" and "const: kinetic,ktz8866"
> > - Change "additionalProperties" to "unevaluatedProperties"
> >
> > Changes in v3:
> > - Add Krzysztof's R-b
> >
> > Changes in v4:
> > - Drop Krzysztof's R-b
> > - Add some new properties
> >
> > .../leds/backlight/kinetic,ktz8866.yaml | 54 +++++++++++++++++++
> > 1 file changed, 54 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml b/Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml
> > new file mode 100644
> > index 000000000000..18571d69accb
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml
> > @@ -0,0 +1,54 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/leds/backlight/kinetic,ktz8866.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Kinetic Technologies KTZ8866 backlight
> > +
> > +maintainers:
> > + - Jianhua Lu <[email protected]>
> > +
> > +description: |
> > + The Kinetic Technologies KTZ8866 is a high efficiency 6-sinks led backlight
> > + with dual lcd bias power.
> > + https://www.kinet-ic.com/ktz8866/
> > +
> > +allOf:
> > + - $ref: common.yaml#
> > +
> > +properties:
> > + compatible:
> > + const: kinetic,ktz8866
> > +
> > + current-num-sinks:
> > + description: Number of LED current sinks.
> > +
> > + current-ramping-time:
> > + description: LED current ramping time.
>
> Needs to document know what units this value is expressed in. IIRC
> this should be expressed in SI units and included the property name.
> Something like:
>
> current-ramping-time-us:
> description: LED current ramping time in microseconds.
>
Get it, I will send a new version patch.
>
> > +
> > + led-ramping-time:
> > + description: LED on/off ramping time.
>
> +1
>
>
> Daniel.
On Tue, Jan 17, 2023 at 09:47:41PM +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 <[email protected]>
> ---
> 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.
>
> MAINTAINERS | 6 +
> drivers/video/backlight/Kconfig | 8 ++
> drivers/video/backlight/Makefile | 1 +
> drivers/video/backlight/ktz8866.c | 195 ++++++++++++++++++++++++++++++
> 4 files changed, 210 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 <[email protected]>
> S: Maintained
> F: tools/testing/ktest
>
> +KTZ8866 BACKLIGHT DRIVER
> +M: Jianhua Lu <[email protected]>
> +S: Maintained
> +F: Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml
> +F: drivers/video/backlight/ktz8866.c
> +
> L3MDEV
> M: David Ahern <[email protected]>
> L: [email protected]
> 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..98916f92d069
> --- /dev/null
> +++ b/drivers/video/backlight/ktz8866.c
> @@ -0,0 +1,195 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Backlight driver for the Kinetic KTZ8866
> + *
> + * Copyright (C) 2023 Jianhua Lu <[email protected]>
Shouldn't this be:
Copyright (C) 2022, 2023 Jianhua Lu <[email protected]>
> +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;
There is still pending feedback from v3.
| Please set the scale property correctly. "Unknown" is never correct for
| new drivers.
Do not ignore feedback. You should either act on it or, if you disagree
or need additional clarification then, reply on the mail thread.
Daniel.
On Tue, Jan 17, 2023 at 09:47:42PM +0800, Jianhua Lu wrote:
> Add Kinetic KTZ8866 backlight binding documentation.
>
> Signed-off-by: Jianhua Lu <[email protected]>
Might be a good idea to take a look at this bit of the docs because
the patchset is not in the right order (I.5):
https://docs.kernel.org/devicetree/bindings/submitting-patches.html
> ---
> Changes in v2:
> - Remove "items" between "compatible" and "const: kinetic,ktz8866"
> - Change "additionalProperties" to "unevaluatedProperties"
>
> Changes in v3:
> - Add Krzysztof's R-b
>
> Changes in v4:
> - Drop Krzysztof's R-b
> - Add some new properties
>
> .../leds/backlight/kinetic,ktz8866.yaml | 54 +++++++++++++++++++
> 1 file changed, 54 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml
>
> diff --git a/Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml b/Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml
> new file mode 100644
> index 000000000000..18571d69accb
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml
> @@ -0,0 +1,54 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/leds/backlight/kinetic,ktz8866.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Kinetic Technologies KTZ8866 backlight
> +
> +maintainers:
> + - Jianhua Lu <[email protected]>
> +
> +description: |
> + The Kinetic Technologies KTZ8866 is a high efficiency 6-sinks led backlight
> + with dual lcd bias power.
> + https://www.kinet-ic.com/ktz8866/
> +
> +allOf:
> + - $ref: common.yaml#
> +
> +properties:
> + compatible:
> + const: kinetic,ktz8866
> +
> + current-num-sinks:
> + description: Number of LED current sinks.
> +
> + current-ramping-time:
> + description: LED current ramping time.
Needs to document know what units this value is expressed in. IIRC
this should be expressed in SI units and included the property name.
Something like:
current-ramping-time-us:
description: LED current ramping time in microseconds.
> +
> + led-ramping-time:
> + description: LED on/off ramping time.
+1
Daniel.
On Tue, Jan 17, 2023 at 10:12:18PM +0800, Jianhua Lu wrote:
> On Tue, Jan 17, 2023 at 02:04:05PM +0000, Daniel Thompson wrote:
> > On Tue, Jan 17, 2023 at 09:47:41PM +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 <[email protected]>
> > > ---
> > > 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.
> > >
> > > MAINTAINERS | 6 +
> > > drivers/video/backlight/Kconfig | 8 ++
> > > drivers/video/backlight/Makefile | 1 +
> > > drivers/video/backlight/ktz8866.c | 195 ++++++++++++++++++++++++++++++
> > > 4 files changed, 210 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 <[email protected]>
> > > S: Maintained
> > > F: tools/testing/ktest
> > >
> > > +KTZ8866 BACKLIGHT DRIVER
> > > +M: Jianhua Lu <[email protected]>
> > > +S: Maintained
> > > +F: Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml
> > > +F: drivers/video/backlight/ktz8866.c
> > > +
> > > L3MDEV
> > > M: David Ahern <[email protected]>
> > > L: [email protected]
> > > 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..98916f92d069
> > > --- /dev/null
> > > +++ b/drivers/video/backlight/ktz8866.c
> > > @@ -0,0 +1,195 @@
> > > +// SPDX-License-Identifier: GPL-2.0-only
> > > +/*
> > > + * Backlight driver for the Kinetic KTZ8866
> > > + *
> > > + * Copyright (C) 2023 Jianhua Lu <[email protected]>
> >
> > Shouldn't this be:
> > Copyright (C) 2022, 2023 Jianhua Lu <[email protected]>
> >
> > > +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;
> >
> > There is still pending feedback from v3.
> >
> > | Please set the scale property correctly. "Unknown" is never correct for
> > | new drivers.
> Do you means backlight_properties.backlight_scale?
props.scale = BACKLIGHT_SCALE_<whatever_is_correct_for_this_hardware>;
(the memset means you are currently setting the scale to
BACKLIGHT_SCALE_UNKNOWN )
Daniel.
On Tue, Jan 17, 2023 at 02:37:07PM +0000, Daniel Thompson wrote:
> On Tue, Jan 17, 2023 at 10:12:18PM +0800, Jianhua Lu wrote:
> > On Tue, Jan 17, 2023 at 02:04:05PM +0000, Daniel Thompson wrote:
> > > On Tue, Jan 17, 2023 at 09:47:41PM +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 <[email protected]>
> > > > ---
> > > > 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.
> > > >
> > > > MAINTAINERS | 6 +
> > > > drivers/video/backlight/Kconfig | 8 ++
> > > > drivers/video/backlight/Makefile | 1 +
> > > > drivers/video/backlight/ktz8866.c | 195 ++++++++++++++++++++++++++++++
> > > > 4 files changed, 210 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 <[email protected]>
> > > > S: Maintained
> > > > F: tools/testing/ktest
> > > >
> > > > +KTZ8866 BACKLIGHT DRIVER
> > > > +M: Jianhua Lu <[email protected]>
> > > > +S: Maintained
> > > > +F: Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml
> > > > +F: drivers/video/backlight/ktz8866.c
> > > > +
> > > > L3MDEV
> > > > M: David Ahern <[email protected]>
> > > > L: [email protected]
> > > > 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..98916f92d069
> > > > --- /dev/null
> > > > +++ b/drivers/video/backlight/ktz8866.c
> > > > @@ -0,0 +1,195 @@
> > > > +// SPDX-License-Identifier: GPL-2.0-only
> > > > +/*
> > > > + * Backlight driver for the Kinetic KTZ8866
> > > > + *
> > > > + * Copyright (C) 2023 Jianhua Lu <[email protected]>
> > >
> > > Shouldn't this be:
> > > Copyright (C) 2022, 2023 Jianhua Lu <[email protected]>
> > >
> > > > +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;
> > >
> > > There is still pending feedback from v3.
> > >
> > > | Please set the scale property correctly. "Unknown" is never correct for
> > > | new drivers.
> > Do you means backlight_properties.backlight_scale?
>
> props.scale = BACKLIGHT_SCALE_<whatever_is_correct_for_this_hardware>;
>
> (the memset means you are currently setting the scale to
> BACKLIGHT_SCALE_UNKNOWN )
Thanks for explanation.
>
>
> Daniel.