Hello,
This series adds support for the Kinetic KTD2801 LED backlight driver
IC found in samsung,coreprimevelte.
Support is already upstream for the somewhat similar KTD2692 flash
driver, and this series since v3 also moves its ExpressWire code into a
separate library and converts the KTD2692 driver to use that library.
Signed-off-by: Duje Mihanović <[email protected]>
---
Changes in v5:
- Split up ExpressWire library and KTD2692 conversion
- Rebase on v6.8-rc1
- Link to v4: https://lore.kernel.org/r/[email protected]
Changes in v4:
- Drop 'extern' keywords in leds-expresswire.h
- Add 'expresswire_write_u8' to leds-expresswire.c and use it in the two
drivers
- Move GPIOLIB dependency to LEDS_EXPRESSWIRE instead of letting clients
handle it
- Drop time constant macros
- Drop delay.h include in ktd2692
- Drop bits.h and delay.h includes in ktd2801
- Link to v3: https://lore.kernel.org/r/[email protected]
Changes in v3:
- Split ExpressWire code into library (and convert KTD2692 to use this
library)
- Rewrite commit messages
- Add link to datasheet
- Drop of.h include in ktd2801
- Use _cansleep and usleep_range when powering off
- Clean up bitwise operation in update_status
- Link to v2: https://lore.kernel.org/r/[email protected]
Changes in v2:
- Address maintainer comments:
- Drop MODULE_ALIAS
- Rename enable-gpios to ctrl-gpios
- Rename ktd2801_backlight->desc to ktd2801_backlight->gpiod
- Give time constants more descriptive names and note their origins in
Samsung driver
- Convert to GPIO_ACTIVE_HIGH
- Update trailers
- Link to v1: https://lore.kernel.org/r/[email protected]
---
Duje Mihanović (4):
leds: introduce ExpressWire library
leds: ktd2692: convert to use ExpressWire library
dt-bindings: backlight: add Kinetic KTD2801 binding
backlight: Add Kinetic KTD2801 backlight support
.../bindings/leds/backlight/kinetic,ktd2801.yaml | 46 ++++++++
MAINTAINERS | 13 +++
drivers/leds/Kconfig | 4 +
drivers/leds/Makefile | 3 +
drivers/leds/flash/Kconfig | 2 +-
drivers/leds/flash/leds-ktd2692.c | 116 +++++--------------
drivers/leds/leds-expresswire.c | 68 +++++++++++
drivers/video/backlight/Kconfig | 7 ++
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/ktd2801-backlight.c | 128 +++++++++++++++++++++
include/linux/leds-expresswire.h | 36 ++++++
11 files changed, 334 insertions(+), 90 deletions(-)
---
base-commit: 6613476e225e090cc9aad49be7fa504e290dd33d
change-id: 20231004-ktd2801-0f3883cb59d0
Best regards,
--
Duje Mihanović <[email protected]>
KTD2801 is a LED backlight driver IC found in samsung,coreprimevelte.
The brightness can be set using PWM or the ExpressWire protocol. Add
support for the KTD2801.
Reviewed-by: Linus Walleij <[email protected]>
Reviewed-by: Daniel Thompson <[email protected]>
Signed-off-by: Duje Mihanović <[email protected]>
---
MAINTAINERS | 6 ++
drivers/video/backlight/Kconfig | 7 ++
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/ktd2801-backlight.c | 128 ++++++++++++++++++++++++++++
4 files changed, 142 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index e1c83e0e837a..01cd1a460907 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12052,6 +12052,12 @@ S: Maintained
F: Documentation/devicetree/bindings/leds/backlight/kinetic,ktd253.yaml
F: drivers/video/backlight/ktd253-backlight.c
+KTD2801 BACKLIGHT DRIVER
+M: Duje Mihanović <[email protected]>
+S: Maintained
+F: Documentation/devicetree/bindings/leds/backlight/kinetic,ktd2801.yaml
+F: drivers/video/backlight/ktd2801-backlight.c
+
KTEST
M: Steven Rostedt <[email protected]>
M: John Hawley <[email protected]>
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index ea2d0d69bd8c..230bca07b09d 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -183,6 +183,13 @@ config BACKLIGHT_KTD253
which is a 1-wire GPIO-controlled backlight found in some mobile
phones.
+config BACKLIGHT_KTD2801
+ tristate "Backlight Driver for Kinetic KTD2801"
+ select LEDS_EXPRESSWIRE
+ help
+ Say Y to enable the backlight driver for the Kinetic KTD2801 1-wire
+ GPIO-controlled backlight found in Samsung Galaxy Core Prime VE LTE.
+
config BACKLIGHT_KTZ8866
tristate "Backlight Driver for Kinetic KTZ8866"
depends on I2C
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index 06966cb20459..8d2cb252042d 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -34,6 +34,7 @@ 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-$(CONFIG_BACKLIGHT_KTD2801) += ktd2801-backlight.o
obj-$(CONFIG_BACKLIGHT_KTZ8866) += ktz8866.o
obj-$(CONFIG_BACKLIGHT_LM3533) += lm3533_bl.o
obj-$(CONFIG_BACKLIGHT_LM3630A) += lm3630a_bl.o
diff --git a/drivers/video/backlight/ktd2801-backlight.c b/drivers/video/backlight/ktd2801-backlight.c
new file mode 100644
index 000000000000..c020acff40f1
--- /dev/null
+++ b/drivers/video/backlight/ktd2801-backlight.c
@@ -0,0 +1,128 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Datasheet:
+ * https://www.kinet-ic.com/uploads/web/KTD2801/KTD2801-04b.pdf
+ */
+#include <linux/backlight.h>
+#include <linux/gpio/consumer.h>
+#include <linux/leds-expresswire.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+
+#define KTD2801_DEFAULT_BRIGHTNESS 100
+#define KTD2801_MAX_BRIGHTNESS 255
+
+/* These values have been extracted from Samsung's driver. */
+const struct expresswire_timing ktd2801_timing = {
+ .poweroff_us = 2600,
+ .detect_delay_us = 150,
+ .detect_us = 270,
+ .data_start_us = 5,
+ .short_bitset_us = 5,
+ .long_bitset_us = 15,
+ .end_of_data_low_us = 10,
+ .end_of_data_high_us = 350
+};
+
+struct ktd2801_backlight {
+ struct expresswire_common_props props;
+ struct backlight_device *bd;
+ bool was_on;
+};
+
+static int ktd2801_update_status(struct backlight_device *bd)
+{
+ struct ktd2801_backlight *ktd2801 = bl_get_data(bd);
+ u8 brightness = (u8) backlight_get_brightness(bd);
+
+ if (backlight_is_blank(bd)) {
+ expresswire_power_off(&ktd2801->props);
+ ktd2801->was_on = false;
+ return 0;
+ }
+
+ if (!ktd2801->was_on) {
+ expresswire_enable(&ktd2801->props);
+ ktd2801->was_on = true;
+ }
+
+ expresswire_write_u8(&ktd2801->props, brightness);
+
+ return 0;
+}
+
+static const struct backlight_ops ktd2801_backlight_ops = {
+ .update_status = ktd2801_update_status,
+};
+
+static int ktd2801_backlight_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct backlight_device *bd;
+ struct ktd2801_backlight *ktd2801;
+ u32 brightness, max_brightness;
+ int ret;
+
+ ktd2801 = devm_kzalloc(dev, sizeof(*ktd2801), GFP_KERNEL);
+ if (!ktd2801)
+ return -ENOMEM;
+ ktd2801->was_on = true;
+ ktd2801->props.timing = ktd2801_timing;
+
+ ret = device_property_read_u32(dev, "max-brightness", &max_brightness);
+ if (ret)
+ max_brightness = KTD2801_MAX_BRIGHTNESS;
+ if (max_brightness > KTD2801_MAX_BRIGHTNESS) {
+ dev_err(dev, "illegal max brightness specified\n");
+ max_brightness = KTD2801_MAX_BRIGHTNESS;
+ }
+
+ ret = device_property_read_u32(dev, "default-brightness", &brightness);
+ if (ret)
+ brightness = KTD2801_DEFAULT_BRIGHTNESS;
+ if (brightness > max_brightness) {
+ dev_err(dev, "default brightness exceeds max\n");
+ brightness = max_brightness;
+ }
+
+ ktd2801->props.ctrl_gpio = devm_gpiod_get(dev, "ctrl", GPIOD_OUT_HIGH);
+ if (IS_ERR(ktd2801->props.ctrl_gpio))
+ return dev_err_probe(dev, PTR_ERR(ktd2801->props.ctrl_gpio),
+ "failed to get backlight GPIO");
+ gpiod_set_consumer_name(ktd2801->props.ctrl_gpio, dev_name(dev));
+
+ bd = devm_backlight_device_register(dev, dev_name(dev), dev, ktd2801,
+ &ktd2801_backlight_ops, NULL);
+ if (IS_ERR(bd))
+ return dev_err_probe(dev, PTR_ERR(bd),
+ "failed to register backlight");
+
+ bd->props.max_brightness = max_brightness;
+ bd->props.brightness = brightness;
+
+ ktd2801->bd = bd;
+ platform_set_drvdata(pdev, bd);
+ backlight_update_status(bd);
+
+ return 0;
+}
+
+static const struct of_device_id ktd2801_of_match[] = {
+ { .compatible = "kinetic,ktd2801" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ktd2801_of_match);
+
+static struct platform_driver ktd2801_backlight_driver = {
+ .driver = {
+ .name = "ktd2801-backlight",
+ .of_match_table = ktd2801_of_match,
+ },
+ .probe = ktd2801_backlight_probe,
+};
+module_platform_driver(ktd2801_backlight_driver);
+
+MODULE_IMPORT_NS(EXPRESSWIRE);
+MODULE_AUTHOR("Duje Mihanović <[email protected]>");
+MODULE_DESCRIPTION("Kinetic KTD2801 Backlight Driver");
+MODULE_LICENSE("GPL");
--
2.43.0
KTD2801 is a LED backlight driver IC found in samsung,coreprimevelte.
The brightness can be set using PWM or the ExpressWire protocol. Add
a DT binding for the KTD2801.
Reviewed-by: Krzysztof Kozlowski <[email protected]>
Reviewed-by: Linus Walleij <[email protected]>
Reviewed-by: Daniel Thompson <[email protected]>
Signed-off-by: Duje Mihanović <[email protected]>
---
.../bindings/leds/backlight/kinetic,ktd2801.yaml | 46 ++++++++++++++++++++++
1 file changed, 46 insertions(+)
diff --git a/Documentation/devicetree/bindings/leds/backlight/kinetic,ktd2801.yaml b/Documentation/devicetree/bindings/leds/backlight/kinetic,ktd2801.yaml
new file mode 100644
index 000000000000..b005065e0f48
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/backlight/kinetic,ktd2801.yaml
@@ -0,0 +1,46 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/backlight/kinetic,ktd2801.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Kinetic Technologies KTD2801 one-wire backlight
+
+maintainers:
+ - Duje Mihanović <[email protected]>
+
+description: |
+ The Kinetic Technologies KTD2801 is a LED backlight driver controlled
+ by a single GPIO line. The driver can be controlled with a PWM signal
+ or by pulsing the GPIO line to set the backlight level. This is called
+ "ExpressWire".
+
+allOf:
+ - $ref: common.yaml#
+
+properties:
+ compatible:
+ const: kinetic,ktd2801
+
+ ctrl-gpios:
+ maxItems: 1
+
+ default-brightness: true
+ max-brightness: true
+
+required:
+ - compatible
+ - ctrl-gpios
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+
+ backlight {
+ compatible = "kinetic,ktd2801";
+ ctrl-gpios = <&gpio 97 GPIO_ACTIVE_HIGH>;
+ max-brightness = <210>;
+ default-brightness = <100>;
+ };
--
2.43.0
On Thu, 25 Jan 2024 16:30:52 +0100, Duje Mihanović wrote:
> This series adds support for the Kinetic KTD2801 LED backlight driver
> IC found in samsung,coreprimevelte.
>
> Support is already upstream for the somewhat similar KTD2692 flash
> driver, and this series since v3 also moves its ExpressWire code into a
> separate library and converts the KTD2692 driver to use that library.
>
> [...]
Applied, thanks!
[1/4] leds: introduce ExpressWire library
commit: 25ae5f5f4168bbf91e7b6b126d24c30c91ef952e
[2/4] leds: ktd2692: convert to use ExpressWire library
commit: e59a15af7aa690fa0997758df23069a9f0756c49
[3/4] dt-bindings: backlight: add Kinetic KTD2801 binding
commit: 4ac621a418ce8f4c562b50ea6f676196bd5262da
[4/4] backlight: Add Kinetic KTD2801 backlight support
commit: 66c76c1cd984c14660453dfa2118014817924375
--
Lee Jones [李琼斯]