* [PATCH 1/3 v3] dt-bindings: backlight: Add some common backlight properties
@ 2020-08-19 20:51 Linus Walleij
2020-08-19 20:51 ` [PATCH 2/3 v3] dt-bindings: backlight: Add Kinetic KTD253 bindings Linus Walleij
` (4 more replies)
0 siblings, 5 replies; 12+ messages in thread
From: Linus Walleij @ 2020-08-19 20:51 UTC (permalink / raw)
To: Lee Jones, Daniel Thompson, Jingoo Han, dri-devel
Cc: devicetree, Sam Ravnborg
Let's use a common.yaml include for the backlight like we do with
the LEDs. The LEDs are inherently incompatible so their bindings
cannot be reused for backlight.
Cc: devicetree@vger.kernel.org
Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v2->v3:
- Drop the | for the description
- Drop the "default-on" property, we're not using it.
- Drop the minimum 0 for unsigned u32:s
ChangeLog v1->v2:
- New patch as suggested by Sam.
---
.../bindings/leds/backlight/common.yaml | 34 +++++++++++++++++++
1 file changed, 34 insertions(+)
create mode 100644 Documentation/devicetree/bindings/leds/backlight/common.yaml
diff --git a/Documentation/devicetree/bindings/leds/backlight/common.yaml b/Documentation/devicetree/bindings/leds/backlight/common.yaml
new file mode 100644
index 000000000000..4e7e95e331a5
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/backlight/common.yaml
@@ -0,0 +1,34 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/backlight/common.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Common backlight properties
+
+maintainers:
+ - Lee Jones <lee.jones@linaro.org>
+ - Daniel Thompson <daniel.thompson@linaro.org>
+ - Jingoo Han <jingoohan1@gmail.com>
+
+description:
+ Backlight devices provide backlight for different types of graphical
+ displays. They are typically but not necessarily implemented using a white
+ LED powered by a boost converter.
+
+properties:
+ default-brightness:
+ description:
+ The default brightness that should be applied to the LED by the operating
+ system on start-up. The brightness should not exceed the brightness the
+ LED can provide.
+ $ref: /schemas/types.yaml#definitions/uint32
+
+ max-brightness:
+ description:
+ Normally the maximum brightness is determined by the hardware and this
+ property is not required. This property is used to put a software limit
+ on the brightness apart from what the driver says, as it could happen
+ that a LED can be made so bright that it gets damaged or causes damage
+ due to restrictions in a specific system, such as mounting conditions.
+ $ref: /schemas/types.yaml#definitions/uint32
--
2.26.2
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https://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH 2/3 v3] dt-bindings: backlight: Add Kinetic KTD253 bindings
2020-08-19 20:51 [PATCH 1/3 v3] dt-bindings: backlight: Add some common backlight properties Linus Walleij
@ 2020-08-19 20:51 ` Linus Walleij
2020-08-20 16:38 ` Daniel Thompson
` (2 more replies)
2020-08-19 20:51 ` [PATCH 3/3 v3] backlight: Add Kinetic KTD253 backlight driver Linus Walleij
` (3 subsequent siblings)
4 siblings, 3 replies; 12+ messages in thread
From: Linus Walleij @ 2020-08-19 20:51 UTC (permalink / raw)
To: Lee Jones, Daniel Thompson, Jingoo Han, dri-devel
Cc: devicetree, Sam Ravnborg
This adds device tree bindings for the Kinetic KTD253
white LED backlight driver.
Cc: devicetree@vger.kernel.org
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v2->v3:
- Drop the pointless cargo-culted "default-on" property that
we were not using
- Correct the brightness in the example to something legal (13)
ChangeLog v1->v2:
- Create common.yaml for backlight as suggested by Sam and
use that.
- Rename the GPIO line "enable-gpios"
---
.../leds/backlight/kinetic,ktd253.yaml | 46 +++++++++++++++++++
1 file changed, 46 insertions(+)
create mode 100644 Documentation/devicetree/bindings/leds/backlight/kinetic,ktd253.yaml
diff --git a/Documentation/devicetree/bindings/leds/backlight/kinetic,ktd253.yaml b/Documentation/devicetree/bindings/leds/backlight/kinetic,ktd253.yaml
new file mode 100644
index 000000000000..7a6ec1f8c0f3
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/backlight/kinetic,ktd253.yaml
@@ -0,0 +1,46 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/backlight/kinetic,ktd253.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Kinetic Technologies KTD253 one-wire backlight
+
+maintainers:
+ - Linus Walleij <linus.walleij@linaro.org>
+
+description: |
+ The Kinetic Technologies KTD253 is a white LED backlight that is
+ controlled by a single GPIO line. If you just turn on the backlight
+ it goes to maximum backlight then you can set the level of backlight
+ using pulses on the enable wire. This is sometimes referred to as
+ "expresswire".
+
+allOf:
+ - $ref: common.yaml#
+
+properties:
+ compatible:
+ const: kinetic,ktd253
+
+ enable-gpios:
+ description: GPIO to use to enable/disable and dim the backlight.
+ maxItems: 1
+
+ default-brightness: true
+ max-brightness: true
+
+required:
+ - compatible
+ - enable-gpios
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+ backlight {
+ compatible = "kinetic,ktd253";
+ enable-gpios = <&gpio2 5 GPIO_ACTIVE_HIGH>;
+ default-brightness = <13>;
+ };
--
2.26.2
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH 3/3 v3] backlight: Add Kinetic KTD253 backlight driver
2020-08-19 20:51 [PATCH 1/3 v3] dt-bindings: backlight: Add some common backlight properties Linus Walleij
2020-08-19 20:51 ` [PATCH 2/3 v3] dt-bindings: backlight: Add Kinetic KTD253 bindings Linus Walleij
@ 2020-08-19 20:51 ` Linus Walleij
2020-08-28 10:47 ` Lee Jones
2020-08-20 16:37 ` [PATCH 1/3 v3] dt-bindings: backlight: Add some common backlight properties Daniel Thompson
` (2 subsequent siblings)
4 siblings, 1 reply; 12+ messages in thread
From: Linus Walleij @ 2020-08-19 20:51 UTC (permalink / raw)
To: Lee Jones, Daniel Thompson, Jingoo Han, dri-devel; +Cc: Sam Ravnborg
The Kinetic KTD253 backlight driver is controlled with a
single GPIO line, but still supports a range of brightness
settings by sending fast pulses on the line.
This is based off the source code release for the Samsung
GT-S7710 mobile phone.
Cc: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v2->v3:
- Collect Daniel's review tag.
ChangeLog v1->v2:
- Expose the 32 actual hardware levels of brightness directly
instead of using an interpolated "brightness" table.
- Use the new backlight_get_brightness() helper.
- Call backlight_update_status() in probe instead of calling
local functions to sync brightness.
- Sort includes alphabetically.
- Name the GPIO line "enable" and grab that in accordance
with the change to the DT bindings.
---
MAINTAINERS | 6 +
drivers/video/backlight/Kconfig | 8 +
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/ktd253-backlight.c | 198 +++++++++++++++++++++
4 files changed, 213 insertions(+)
create mode 100644 drivers/video/backlight/ktd253-backlight.c
diff --git a/MAINTAINERS b/MAINTAINERS
index deaafb617361..ef6b4a279d25 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9722,6 +9722,12 @@ F: Documentation/admin-guide/auxdisplay/ks0108.rst
F: drivers/auxdisplay/ks0108.c
F: include/linux/ks0108.h
+KTD253 BACKLIGHT DRIVER
+M: Linus Walleij <linus.walleij@linaro.org>
+S: Maintained
+F: Documentation/devicetree/bindings/leds/backlight/kinetic,ktd253.yaml
+F: drivers/video/backlight/ktd253-backlight.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 87f9fc238d28..d83c87b902c1 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -182,6 +182,14 @@ config BACKLIGHT_IPAQ_MICRO
computers. Say yes if you have one of the h3100/h3600/h3700
machines.
+config BACKLIGHT_KTD253
+ tristate "Backlight Driver for Kinetic KTD253"
+ depends on GPIOLIB || COMPILE_TEST
+ help
+ Say y to enabled the backlight driver for the Kinetic KTD253
+ which is a 1-wire GPIO-controlled backlight found in some mobile
+ phones.
+
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 13463b99f1f9..685f3f1ca4df 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -35,6 +35,7 @@ obj-$(CONFIG_BACKLIGHT_GPIO) += gpio_backlight.o
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-$(CONFIG_BACKLIGHT_LM3533) += lm3533_bl.o
obj-$(CONFIG_BACKLIGHT_LM3630A) += lm3630a_bl.o
obj-$(CONFIG_BACKLIGHT_LM3639) += lm3639_bl.o
diff --git a/drivers/video/backlight/ktd253-backlight.c b/drivers/video/backlight/ktd253-backlight.c
new file mode 100644
index 000000000000..e3fee3f1f582
--- /dev/null
+++ b/drivers/video/backlight/ktd253-backlight.c
@@ -0,0 +1,198 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Backlight driver for the Kinetic KTD253
+ * Based on code and know-how from the Samsung GT-S7710
+ * Gareth Phillips <gareth.phillips@samsung.com>
+ */
+#include <linux/backlight.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/fb.h>
+#include <linux/gpio/consumer.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/limits.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/slab.h>
+
+/* Current ratio is n/32 from 1/32 to 32/32 */
+#define KTD253_MIN_RATIO 1
+#define KTD253_MAX_RATIO 32
+#define KTD253_DEFAULT_RATIO 13
+
+#define KTD253_T_LOW_NS (200 + 10) /* Additional 10ns as safety factor */
+#define KTD253_T_HIGH_NS (200 + 10) /* Additional 10ns as safety factor */
+#define KTD253_T_OFF_MS 3
+
+struct ktd253_backlight {
+ struct device *dev;
+ struct backlight_device *bl;
+ struct gpio_desc *gpiod;
+ u16 ratio;
+};
+
+static int ktd253_backlight_update_status(struct backlight_device *bl)
+{
+ struct ktd253_backlight *ktd253 = bl_get_data(bl);
+ int brightness = backlight_get_brightness(bl);
+ u16 target_ratio;
+ u16 current_ratio = ktd253->ratio;
+ unsigned long flags;
+
+ dev_dbg(ktd253->dev, "new brightness/ratio: %d/32\n", brightness);
+
+ target_ratio = brightness;
+
+ if (target_ratio == current_ratio)
+ /* This is already right */
+ return 0;
+
+ if (target_ratio == 0) {
+ gpiod_set_value_cansleep(ktd253->gpiod, 0);
+ /*
+ * We need to keep the GPIO low for at least this long
+ * to actually switch the KTD253 off.
+ */
+ msleep(KTD253_T_OFF_MS);
+ ktd253->ratio = 0;
+ return 0;
+ }
+
+ if (current_ratio == 0) {
+ gpiod_set_value_cansleep(ktd253->gpiod, 1);
+ ndelay(KTD253_T_HIGH_NS);
+ /* We always fall back to this when we power on */
+ current_ratio = KTD253_MAX_RATIO;
+ }
+
+ /*
+ * WARNING:
+ * The loop to set the correct current level is performed
+ * with interrupts disabled as it is timing critical.
+ * The maximum number of cycles of the loop is 32
+ * so the time taken will be (T_LOW_NS + T_HIGH_NS + loop_time) * 32,
+ */
+ local_irq_save(flags);
+ while (current_ratio != target_ratio) {
+ /*
+ * These GPIO operations absolutely can NOT sleep so no
+ * _cansleep suffixes, and no using GPIO expanders on
+ * slow buses for this!
+ */
+ gpiod_set_value(ktd253->gpiod, 0);
+ ndelay(KTD253_T_LOW_NS);
+ gpiod_set_value(ktd253->gpiod, 1);
+ ndelay(KTD253_T_HIGH_NS);
+ /* After 1/32 we loop back to 32/32 */
+ if (current_ratio == KTD253_MIN_RATIO)
+ current_ratio = KTD253_MAX_RATIO;
+ else
+ current_ratio--;
+ }
+ local_irq_restore(flags);
+ ktd253->ratio = current_ratio;
+
+ dev_dbg(ktd253->dev, "new ratio set to %d/32\n", target_ratio);
+
+ return 0;
+}
+
+static const struct backlight_ops ktd253_backlight_ops = {
+ .options = BL_CORE_SUSPENDRESUME,
+ .update_status = ktd253_backlight_update_status,
+};
+
+static int ktd253_backlight_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct backlight_device *bl;
+ struct ktd253_backlight *ktd253;
+ u32 max_brightness;
+ u32 brightness;
+ int ret;
+
+ ktd253 = devm_kzalloc(dev, sizeof(*ktd253), GFP_KERNEL);
+ if (!ktd253)
+ return -ENOMEM;
+ ktd253->dev = dev;
+
+ ret = device_property_read_u32(dev, "max-brightness", &max_brightness);
+ if (ret)
+ max_brightness = KTD253_MAX_RATIO;
+ if (max_brightness > KTD253_MAX_RATIO) {
+ /* Clamp brightness to hardware max */
+ dev_err(dev, "illegal max brightness specified\n");
+ max_brightness = KTD253_MAX_RATIO;
+ }
+
+ ret = device_property_read_u32(dev, "default-brightness", &brightness);
+ if (ret)
+ brightness = KTD253_DEFAULT_RATIO;
+ if (brightness > max_brightness) {
+ /* Clamp default brightness to max brightness */
+ dev_err(dev, "default brightness exceeds max brightness\n");
+ brightness = max_brightness;
+ }
+
+ if (brightness)
+ /* This will be the default ratio when the KTD253 is enabled */
+ ktd253->ratio = KTD253_MAX_RATIO;
+ else
+ ktd253->ratio = 0;
+
+ ktd253->gpiod = devm_gpiod_get(dev, "enable",
+ brightness ? GPIOD_OUT_HIGH :
+ GPIOD_OUT_LOW);
+ if (IS_ERR(ktd253->gpiod)) {
+ ret = PTR_ERR(ktd253->gpiod);
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "gpio line missing or invalid.\n");
+ return ret;
+ }
+ gpiod_set_consumer_name(ktd253->gpiod, dev_name(dev));
+
+ bl = devm_backlight_device_register(dev, dev_name(dev), dev, ktd253,
+ &ktd253_backlight_ops, NULL);
+ if (IS_ERR(bl)) {
+ dev_err(dev, "failed to register backlight\n");
+ return PTR_ERR(bl);
+ }
+ bl->props.max_brightness = max_brightness;
+ /* When we just enable the GPIO line we set max brightness */
+ if (brightness) {
+ bl->props.brightness = brightness;
+ bl->props.power = FB_BLANK_UNBLANK;
+ } else {
+ bl->props.brightness = 0;
+ bl->props.power = FB_BLANK_POWERDOWN;
+ }
+
+ ktd253->bl = bl;
+ platform_set_drvdata(pdev, bl);
+ backlight_update_status(bl);
+
+ return 0;
+}
+
+static const struct of_device_id ktd253_backlight_of_match[] = {
+ { .compatible = "kinetic,ktd253" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, ktd253_backlight_of_match);
+
+static struct platform_driver ktd253_backlight_driver = {
+ .driver = {
+ .name = "ktd253-backlight",
+ .of_match_table = ktd253_backlight_of_match,
+ },
+ .probe = ktd253_backlight_probe,
+};
+module_platform_driver(ktd253_backlight_driver);
+
+MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
+MODULE_DESCRIPTION("Kinetic KTD253 Backlight Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:ktd253-backlight");
--
2.26.2
_______________________________________________
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dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH 1/3 v3] dt-bindings: backlight: Add some common backlight properties
2020-08-19 20:51 [PATCH 1/3 v3] dt-bindings: backlight: Add some common backlight properties Linus Walleij
2020-08-19 20:51 ` [PATCH 2/3 v3] dt-bindings: backlight: Add Kinetic KTD253 bindings Linus Walleij
2020-08-19 20:51 ` [PATCH 3/3 v3] backlight: Add Kinetic KTD253 backlight driver Linus Walleij
@ 2020-08-20 16:37 ` Daniel Thompson
2020-08-24 17:24 ` Rob Herring
2020-08-28 10:46 ` Lee Jones
4 siblings, 0 replies; 12+ messages in thread
From: Daniel Thompson @ 2020-08-20 16:37 UTC (permalink / raw)
To: Linus Walleij; +Cc: Sam Ravnborg, Jingoo Han, Lee Jones, dri-devel, devicetree
On Wed, Aug 19, 2020 at 10:51:48PM +0200, Linus Walleij wrote:
> Let's use a common.yaml include for the backlight like we do with
> the LEDs. The LEDs are inherently incompatible so their bindings
> cannot be reused for backlight.
>
> Cc: devicetree@vger.kernel.org
> Suggested-by: Sam Ravnborg <sam@ravnborg.org>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
> ---
> ChangeLog v2->v3:
> - Drop the | for the description
> - Drop the "default-on" property, we're not using it.
> - Drop the minimum 0 for unsigned u32:s
> ChangeLog v1->v2:
> - New patch as suggested by Sam.
> ---
> .../bindings/leds/backlight/common.yaml | 34 +++++++++++++++++++
> 1 file changed, 34 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/leds/backlight/common.yaml
>
> diff --git a/Documentation/devicetree/bindings/leds/backlight/common.yaml b/Documentation/devicetree/bindings/leds/backlight/common.yaml
> new file mode 100644
> index 000000000000..4e7e95e331a5
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/backlight/common.yaml
> @@ -0,0 +1,34 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/leds/backlight/common.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Common backlight properties
> +
> +maintainers:
> + - Lee Jones <lee.jones@linaro.org>
> + - Daniel Thompson <daniel.thompson@linaro.org>
> + - Jingoo Han <jingoohan1@gmail.com>
> +
> +description:
> + Backlight devices provide backlight for different types of graphical
> + displays. They are typically but not necessarily implemented using a white
> + LED powered by a boost converter.
> +
> +properties:
> + default-brightness:
> + description:
> + The default brightness that should be applied to the LED by the operating
> + system on start-up. The brightness should not exceed the brightness the
> + LED can provide.
> + $ref: /schemas/types.yaml#definitions/uint32
> +
> + max-brightness:
> + description:
> + Normally the maximum brightness is determined by the hardware and this
> + property is not required. This property is used to put a software limit
> + on the brightness apart from what the driver says, as it could happen
> + that a LED can be made so bright that it gets damaged or causes damage
> + due to restrictions in a specific system, such as mounting conditions.
> + $ref: /schemas/types.yaml#definitions/uint32
> --
> 2.26.2
>
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 2/3 v3] dt-bindings: backlight: Add Kinetic KTD253 bindings
2020-08-19 20:51 ` [PATCH 2/3 v3] dt-bindings: backlight: Add Kinetic KTD253 bindings Linus Walleij
@ 2020-08-20 16:38 ` Daniel Thompson
2020-08-24 17:25 ` Rob Herring
2020-08-28 10:46 ` Lee Jones
2 siblings, 0 replies; 12+ messages in thread
From: Daniel Thompson @ 2020-08-20 16:38 UTC (permalink / raw)
To: Linus Walleij; +Cc: Sam Ravnborg, Jingoo Han, Lee Jones, dri-devel, devicetree
On Wed, Aug 19, 2020 at 10:51:49PM +0200, Linus Walleij wrote:
> This adds device tree bindings for the Kinetic KTD253
> white LED backlight driver.
>
> Cc: devicetree@vger.kernel.org
> Cc: Sam Ravnborg <sam@ravnborg.org>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
> ---
> ChangeLog v2->v3:
> - Drop the pointless cargo-culted "default-on" property that
> we were not using
> - Correct the brightness in the example to something legal (13)
> ChangeLog v1->v2:
> - Create common.yaml for backlight as suggested by Sam and
> use that.
> - Rename the GPIO line "enable-gpios"
> ---
> .../leds/backlight/kinetic,ktd253.yaml | 46 +++++++++++++++++++
> 1 file changed, 46 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/leds/backlight/kinetic,ktd253.yaml
>
> diff --git a/Documentation/devicetree/bindings/leds/backlight/kinetic,ktd253.yaml b/Documentation/devicetree/bindings/leds/backlight/kinetic,ktd253.yaml
> new file mode 100644
> index 000000000000..7a6ec1f8c0f3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/backlight/kinetic,ktd253.yaml
> @@ -0,0 +1,46 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/leds/backlight/kinetic,ktd253.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Kinetic Technologies KTD253 one-wire backlight
> +
> +maintainers:
> + - Linus Walleij <linus.walleij@linaro.org>
> +
> +description: |
> + The Kinetic Technologies KTD253 is a white LED backlight that is
> + controlled by a single GPIO line. If you just turn on the backlight
> + it goes to maximum backlight then you can set the level of backlight
> + using pulses on the enable wire. This is sometimes referred to as
> + "expresswire".
> +
> +allOf:
> + - $ref: common.yaml#
> +
> +properties:
> + compatible:
> + const: kinetic,ktd253
> +
> + enable-gpios:
> + description: GPIO to use to enable/disable and dim the backlight.
> + maxItems: 1
> +
> + default-brightness: true
> + max-brightness: true
> +
> +required:
> + - compatible
> + - enable-gpios
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/gpio/gpio.h>
> + backlight {
> + compatible = "kinetic,ktd253";
> + enable-gpios = <&gpio2 5 GPIO_ACTIVE_HIGH>;
> + default-brightness = <13>;
> + };
> --
> 2.26.2
>
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^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 1/3 v3] dt-bindings: backlight: Add some common backlight properties
2020-08-19 20:51 [PATCH 1/3 v3] dt-bindings: backlight: Add some common backlight properties Linus Walleij
` (2 preceding siblings ...)
2020-08-20 16:37 ` [PATCH 1/3 v3] dt-bindings: backlight: Add some common backlight properties Daniel Thompson
@ 2020-08-24 17:24 ` Rob Herring
2020-08-28 10:46 ` Lee Jones
4 siblings, 0 replies; 12+ messages in thread
From: Rob Herring @ 2020-08-24 17:24 UTC (permalink / raw)
To: Linus Walleij
Cc: devicetree, Daniel Thompson, Jingoo Han, dri-devel, Lee Jones,
Sam Ravnborg
On Wed, Aug 19, 2020 at 10:51:48PM +0200, Linus Walleij wrote:
> Let's use a common.yaml include for the backlight like we do with
> the LEDs. The LEDs are inherently incompatible so their bindings
> cannot be reused for backlight.
>
> Cc: devicetree@vger.kernel.org
> Suggested-by: Sam Ravnborg <sam@ravnborg.org>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
> ChangeLog v2->v3:
> - Drop the | for the description
> - Drop the "default-on" property, we're not using it.
> - Drop the minimum 0 for unsigned u32:s
> ChangeLog v1->v2:
> - New patch as suggested by Sam.
> ---
> .../bindings/leds/backlight/common.yaml | 34 +++++++++++++++++++
> 1 file changed, 34 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/leds/backlight/common.yaml
Reviewed-by: Rob Herring <robh@kernel.org>
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^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 2/3 v3] dt-bindings: backlight: Add Kinetic KTD253 bindings
2020-08-19 20:51 ` [PATCH 2/3 v3] dt-bindings: backlight: Add Kinetic KTD253 bindings Linus Walleij
2020-08-20 16:38 ` Daniel Thompson
@ 2020-08-24 17:25 ` Rob Herring
2020-08-28 10:46 ` Lee Jones
2 siblings, 0 replies; 12+ messages in thread
From: Rob Herring @ 2020-08-24 17:25 UTC (permalink / raw)
To: Linus Walleij
Cc: devicetree, Daniel Thompson, Sam Ravnborg, dri-devel, Jingoo Han,
Lee Jones
On Wed, 19 Aug 2020 22:51:49 +0200, Linus Walleij wrote:
> This adds device tree bindings for the Kinetic KTD253
> white LED backlight driver.
>
> Cc: devicetree@vger.kernel.org
> Cc: Sam Ravnborg <sam@ravnborg.org>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
> ChangeLog v2->v3:
> - Drop the pointless cargo-culted "default-on" property that
> we were not using
> - Correct the brightness in the example to something legal (13)
> ChangeLog v1->v2:
> - Create common.yaml for backlight as suggested by Sam and
> use that.
> - Rename the GPIO line "enable-gpios"
> ---
> .../leds/backlight/kinetic,ktd253.yaml | 46 +++++++++++++++++++
> 1 file changed, 46 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/leds/backlight/kinetic,ktd253.yaml
>
Reviewed-by: Rob Herring <robh@kernel.org>
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^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 1/3 v3] dt-bindings: backlight: Add some common backlight properties
2020-08-19 20:51 [PATCH 1/3 v3] dt-bindings: backlight: Add some common backlight properties Linus Walleij
` (3 preceding siblings ...)
2020-08-24 17:24 ` Rob Herring
@ 2020-08-28 10:46 ` Lee Jones
4 siblings, 0 replies; 12+ messages in thread
From: Lee Jones @ 2020-08-28 10:46 UTC (permalink / raw)
To: Linus Walleij
Cc: Jingoo Han, Daniel Thompson, Sam Ravnborg, dri-devel, devicetree
On Wed, 19 Aug 2020, Linus Walleij wrote:
> Let's use a common.yaml include for the backlight like we do with
> the LEDs. The LEDs are inherently incompatible so their bindings
> cannot be reused for backlight.
>
> Cc: devicetree@vger.kernel.org
> Suggested-by: Sam Ravnborg <sam@ravnborg.org>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
> ChangeLog v2->v3:
> - Drop the | for the description
> - Drop the "default-on" property, we're not using it.
> - Drop the minimum 0 for unsigned u32:s
> ChangeLog v1->v2:
> - New patch as suggested by Sam.
> ---
> .../bindings/leds/backlight/common.yaml | 34 +++++++++++++++++++
> 1 file changed, 34 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/leds/backlight/common.yaml
Applied, thanks.
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
_______________________________________________
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^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 2/3 v3] dt-bindings: backlight: Add Kinetic KTD253 bindings
2020-08-19 20:51 ` [PATCH 2/3 v3] dt-bindings: backlight: Add Kinetic KTD253 bindings Linus Walleij
2020-08-20 16:38 ` Daniel Thompson
2020-08-24 17:25 ` Rob Herring
@ 2020-08-28 10:46 ` Lee Jones
2 siblings, 0 replies; 12+ messages in thread
From: Lee Jones @ 2020-08-28 10:46 UTC (permalink / raw)
To: Linus Walleij
Cc: Jingoo Han, Daniel Thompson, Sam Ravnborg, dri-devel, devicetree
On Wed, 19 Aug 2020, Linus Walleij wrote:
> This adds device tree bindings for the Kinetic KTD253
> white LED backlight driver.
>
> Cc: devicetree@vger.kernel.org
> Cc: Sam Ravnborg <sam@ravnborg.org>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
> ChangeLog v2->v3:
> - Drop the pointless cargo-culted "default-on" property that
> we were not using
> - Correct the brightness in the example to something legal (13)
> ChangeLog v1->v2:
> - Create common.yaml for backlight as suggested by Sam and
> use that.
> - Rename the GPIO line "enable-gpios"
> ---
> .../leds/backlight/kinetic,ktd253.yaml | 46 +++++++++++++++++++
> 1 file changed, 46 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/leds/backlight/kinetic,ktd253.yaml
Applied, thanks.
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
_______________________________________________
dri-devel mailing list
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https://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 3/3 v3] backlight: Add Kinetic KTD253 backlight driver
2020-08-19 20:51 ` [PATCH 3/3 v3] backlight: Add Kinetic KTD253 backlight driver Linus Walleij
@ 2020-08-28 10:47 ` Lee Jones
2020-09-30 14:19 ` Linus Walleij
0 siblings, 1 reply; 12+ messages in thread
From: Lee Jones @ 2020-08-28 10:47 UTC (permalink / raw)
To: Linus Walleij; +Cc: Jingoo Han, Daniel Thompson, Sam Ravnborg, dri-devel
On Wed, 19 Aug 2020, Linus Walleij wrote:
> The Kinetic KTD253 backlight driver is controlled with a
> single GPIO line, but still supports a range of brightness
> settings by sending fast pulses on the line.
>
> This is based off the source code release for the Samsung
> GT-S7710 mobile phone.
>
> Cc: Sam Ravnborg <sam@ravnborg.org>
> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
> ChangeLog v2->v3:
> - Collect Daniel's review tag.
> ChangeLog v1->v2:
> - Expose the 32 actual hardware levels of brightness directly
> instead of using an interpolated "brightness" table.
> - Use the new backlight_get_brightness() helper.
> - Call backlight_update_status() in probe instead of calling
> local functions to sync brightness.
> - Sort includes alphabetically.
> - Name the GPIO line "enable" and grab that in accordance
> with the change to the DT bindings.
> ---
> MAINTAINERS | 6 +
> drivers/video/backlight/Kconfig | 8 +
> drivers/video/backlight/Makefile | 1 +
> drivers/video/backlight/ktd253-backlight.c | 198 +++++++++++++++++++++
> 4 files changed, 213 insertions(+)
> create mode 100644 drivers/video/backlight/ktd253-backlight.c
Applied, thanks.
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
_______________________________________________
dri-devel mailing list
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https://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 3/3 v3] backlight: Add Kinetic KTD253 backlight driver
2020-08-28 10:47 ` Lee Jones
@ 2020-09-30 14:19 ` Linus Walleij
2020-10-01 8:59 ` Lee Jones
0 siblings, 1 reply; 12+ messages in thread
From: Linus Walleij @ 2020-09-30 14:19 UTC (permalink / raw)
To: Lee Jones
Cc: Jingoo Han, Daniel Thompson, Sam Ravnborg, open list:DRM PANEL DRIVERS
On Fri, Aug 28, 2020 at 12:47 PM Lee Jones <lee.jones@linaro.org> wrote:
> > create mode 100644 drivers/video/backlight/ktd253-backlight.c
>
> Applied, thanks.
Not to unnecessarily nag but I can't see this in linux-next and since we
are at -rc7 it makes me a bit nervous, is it still gonna be in v5.10?
Yours,
Linus Walleij
_______________________________________________
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https://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 3/3 v3] backlight: Add Kinetic KTD253 backlight driver
2020-09-30 14:19 ` Linus Walleij
@ 2020-10-01 8:59 ` Lee Jones
0 siblings, 0 replies; 12+ messages in thread
From: Lee Jones @ 2020-10-01 8:59 UTC (permalink / raw)
To: Linus Walleij
Cc: Jingoo Han, Daniel Thompson, Sam Ravnborg, open list:DRM PANEL DRIVERS
On Wed, 30 Sep 2020, Linus Walleij wrote:
> On Fri, Aug 28, 2020 at 12:47 PM Lee Jones <lee.jones@linaro.org> wrote:
>
> > > create mode 100644 drivers/video/backlight/ktd253-backlight.c
> >
> > Applied, thanks.
>
> Not to unnecessarily nag but I can't see this in linux-next and since we
> are at -rc7 it makes me a bit nervous, is it still gonna be in v5.10?
Heh, you're right. Apologies, tested and pushed now.
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
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^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~2020-10-01 8:59 UTC | newest]
Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
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2020-08-19 20:51 [PATCH 1/3 v3] dt-bindings: backlight: Add some common backlight properties Linus Walleij
2020-08-19 20:51 ` [PATCH 2/3 v3] dt-bindings: backlight: Add Kinetic KTD253 bindings Linus Walleij
2020-08-20 16:38 ` Daniel Thompson
2020-08-24 17:25 ` Rob Herring
2020-08-28 10:46 ` Lee Jones
2020-08-19 20:51 ` [PATCH 3/3 v3] backlight: Add Kinetic KTD253 backlight driver Linus Walleij
2020-08-28 10:47 ` Lee Jones
2020-09-30 14:19 ` Linus Walleij
2020-10-01 8:59 ` Lee Jones
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