* [PATCH v5 0/4] Kinetic ExpressWire library and KTD2801 backlight driver
@ 2024-01-25 15:30 Duje Mihanović
2024-01-25 15:30 ` [PATCH v5 1/4] leds: introduce ExpressWire library Duje Mihanović
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: Duje Mihanović @ 2024-01-25 15:30 UTC (permalink / raw
To: Lee Jones, Daniel Thompson, Jingoo Han, Pavel Machek, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Helge Deller, Linus Walleij
Cc: Karel Balej, ~postmarketos/upstreaming, phone-devel, dri-devel,
linux-leds, devicetree, linux-kernel, linux-fbdev,
Duje Mihanović, Krzysztof Kozlowski
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 <duje.mihanovic@skole.hr>
---
Changes in v5:
- Split up ExpressWire library and KTD2692 conversion
- Rebase on v6.8-rc1
- Link to v4: https://lore.kernel.org/r/20240122-ktd2801-v4-0-33c986a3eb68@skole.hr
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/20240120-ktd2801-v3-0-fe2cbafffb21@skole.hr
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/20240118-ktd2801-v2-0-425cf32e0769@skole.hr
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/20231005-ktd2801-v1-0-43cd85b0629a@skole.hr
---
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 <duje.mihanovic@skole.hr>
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v5 1/4] leds: introduce ExpressWire library
2024-01-25 15:30 [PATCH v5 0/4] Kinetic ExpressWire library and KTD2801 backlight driver Duje Mihanović
@ 2024-01-25 15:30 ` Duje Mihanović
2024-01-25 15:30 ` [PATCH v5 2/4] leds: ktd2692: convert to use " Duje Mihanović
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Duje Mihanović @ 2024-01-25 15:30 UTC (permalink / raw
To: Lee Jones, Daniel Thompson, Jingoo Han, Pavel Machek, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Helge Deller, Linus Walleij
Cc: Karel Balej, ~postmarketos/upstreaming, phone-devel, dri-devel,
linux-leds, devicetree, linux-kernel, linux-fbdev,
Duje Mihanović
The ExpressWire protocol is shared between at least KTD2692 and KTD2801
with slight differences such as timings and the former not having a
defined set of pulses for enabling the protocol (possibly because it
does not support PWM unlike KTD2801). Despite these differences the
ExpressWire handling code can be shared between the two, so in
preparation for adding KTD2801 support introduce a library implementing
this protocol.
Suggested-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Duje Mihanović <duje.mihanovic@skole.hr>
---
MAINTAINERS | 7 +++++
drivers/leds/Kconfig | 4 +++
drivers/leds/Makefile | 3 ++
drivers/leds/leds-expresswire.c | 68 ++++++++++++++++++++++++++++++++++++++++
include/linux/leds-expresswire.h | 36 +++++++++++++++++++++
5 files changed, 118 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 8d1052fa6a69..e1c83e0e837a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7979,6 +7979,13 @@ S: Maintained
T: git git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat.git
F: fs/exfat/
+EXPRESSWIRE PROTOCOL LIBRARY
+M: Duje Mihanović <duje.mihanovic@skole.hr>
+L: linux-leds@vger.kernel.org
+S: Maintained
+F: drivers/leds/leds-expresswire.c
+F: include/linux/leds-expresswire.h
+
EXT2 FILE SYSTEM
M: Jan Kara <jack@suse.com>
L: linux-ext4@vger.kernel.org
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index d721b254e1e4..64bb2de237e9 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -186,6 +186,10 @@ config LEDS_EL15203000
To compile this driver as a module, choose M here: the module
will be called leds-el15203000.
+config LEDS_EXPRESSWIRE
+ bool
+ depends on GPIOLIB
+
config LEDS_TURRIS_OMNIA
tristate "LED support for CZ.NIC's Turris Omnia"
depends on LEDS_CLASS_MULTICOLOR
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index ce07dc295ff0..effdfc6f1e95 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -91,6 +91,9 @@ obj-$(CONFIG_LEDS_WM831X_STATUS) += leds-wm831x-status.o
obj-$(CONFIG_LEDS_WM8350) += leds-wm8350.o
obj-$(CONFIG_LEDS_WRAP) += leds-wrap.o
+# Kinetic ExpressWire Protocol
+obj-$(CONFIG_LEDS_EXPRESSWIRE) += leds-expresswire.o
+
# LED SPI Drivers
obj-$(CONFIG_LEDS_CR0014114) += leds-cr0014114.o
obj-$(CONFIG_LEDS_DAC124S085) += leds-dac124s085.o
diff --git a/drivers/leds/leds-expresswire.c b/drivers/leds/leds-expresswire.c
new file mode 100644
index 000000000000..89e147b0e019
--- /dev/null
+++ b/drivers/leds/leds-expresswire.c
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Shared library for Kinetic's ExpressWire protocol.
+ * This protocol works by pulsing the ExpressWire IC's control GPIO.
+ * ktd2692 and ktd2801 are known to use this protocol.
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/leds-expresswire.h>
+
+void expresswire_power_off(struct expresswire_common_props *props)
+{
+ gpiod_set_value_cansleep(props->ctrl_gpio, 0);
+ usleep_range(props->timing.poweroff_us, props->timing.poweroff_us * 2);
+}
+EXPORT_SYMBOL_NS_GPL(expresswire_power_off, EXPRESSWIRE);
+
+void expresswire_enable(struct expresswire_common_props *props)
+{
+ gpiod_set_value(props->ctrl_gpio, 1);
+ udelay(props->timing.detect_delay_us);
+ gpiod_set_value(props->ctrl_gpio, 0);
+ udelay(props->timing.detect_us);
+ gpiod_set_value(props->ctrl_gpio, 1);
+}
+EXPORT_SYMBOL_NS_GPL(expresswire_enable, EXPRESSWIRE);
+
+void expresswire_start(struct expresswire_common_props *props)
+{
+ gpiod_set_value(props->ctrl_gpio, 1);
+ udelay(props->timing.data_start_us);
+}
+EXPORT_SYMBOL_NS_GPL(expresswire_start, EXPRESSWIRE);
+
+void expresswire_end(struct expresswire_common_props *props)
+{
+ gpiod_set_value(props->ctrl_gpio, 0);
+ udelay(props->timing.end_of_data_low_us);
+ gpiod_set_value(props->ctrl_gpio, 1);
+ udelay(props->timing.end_of_data_high_us);
+}
+EXPORT_SYMBOL_NS_GPL(expresswire_end, EXPRESSWIRE);
+
+void expresswire_set_bit(struct expresswire_common_props *props, bool bit)
+{
+ if (bit) {
+ gpiod_set_value(props->ctrl_gpio, 0);
+ udelay(props->timing.short_bitset_us);
+ gpiod_set_value(props->ctrl_gpio, 1);
+ udelay(props->timing.long_bitset_us);
+ } else {
+ gpiod_set_value(props->ctrl_gpio, 0);
+ udelay(props->timing.long_bitset_us);
+ gpiod_set_value(props->ctrl_gpio, 1);
+ udelay(props->timing.short_bitset_us);
+ }
+}
+EXPORT_SYMBOL_NS_GPL(expresswire_set_bit, EXPRESSWIRE);
+
+void expresswire_write_u8(struct expresswire_common_props *props, u8 val)
+{
+ expresswire_start(props);
+ for (int i = 7; i >= 0; i--)
+ expresswire_set_bit(props, val & BIT(i));
+ expresswire_end(props);
+}
+EXPORT_SYMBOL_NS_GPL(expresswire_write_u8, EXPRESSWIRE);
diff --git a/include/linux/leds-expresswire.h b/include/linux/leds-expresswire.h
new file mode 100644
index 000000000000..3c61902ccac8
--- /dev/null
+++ b/include/linux/leds-expresswire.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Shared library for Kinetic's ExpressWire protocol.
+ * This protocol works by pulsing the ExpressWire IC's control GPIO.
+ * ktd2692 and ktd2801 are known to use this protocol.
+ */
+
+#ifndef _LEDS_EXPRESSWIRE_H
+#define _LEDS_EXPRESSWIRE_H
+
+#include <linux/gpio/consumer.h>
+
+struct expresswire_timing {
+ unsigned long poweroff_us;
+ unsigned long detect_delay_us;
+ unsigned long detect_us;
+ unsigned long data_start_us;
+ unsigned long end_of_data_low_us;
+ unsigned long end_of_data_high_us;
+ unsigned long short_bitset_us;
+ unsigned long long_bitset_us;
+};
+
+struct expresswire_common_props {
+ struct gpio_desc *ctrl_gpio;
+ struct expresswire_timing timing;
+};
+
+void expresswire_power_off(struct expresswire_common_props *props);
+void expresswire_enable(struct expresswire_common_props *props);
+void expresswire_start(struct expresswire_common_props *props);
+void expresswire_end(struct expresswire_common_props *props);
+void expresswire_set_bit(struct expresswire_common_props *props, bool bit);
+void expresswire_write_u8(struct expresswire_common_props *props, u8 val);
+
+#endif /* _LEDS_EXPRESSWIRE_H */
--
2.43.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v5 2/4] leds: ktd2692: convert to use ExpressWire library
2024-01-25 15:30 [PATCH v5 0/4] Kinetic ExpressWire library and KTD2801 backlight driver Duje Mihanović
2024-01-25 15:30 ` [PATCH v5 1/4] leds: introduce ExpressWire library Duje Mihanović
@ 2024-01-25 15:30 ` Duje Mihanović
2024-01-25 15:30 ` [PATCH v5 3/4] dt-bindings: backlight: add Kinetic KTD2801 binding Duje Mihanović
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Duje Mihanović @ 2024-01-25 15:30 UTC (permalink / raw
To: Lee Jones, Daniel Thompson, Jingoo Han, Pavel Machek, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Helge Deller, Linus Walleij
Cc: Karel Balej, ~postmarketos/upstreaming, phone-devel, dri-devel,
linux-leds, devicetree, linux-kernel, linux-fbdev,
Duje Mihanović
The KTD2692 uses the ExpressWire protocol implemented in the newly
introduced ExpressWire library. Convert the driver to use the library.
Suggested-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Duje Mihanović <duje.mihanovic@skole.hr>
---
drivers/leds/flash/Kconfig | 2 +-
drivers/leds/flash/leds-ktd2692.c | 116 +++++++++-----------------------------
2 files changed, 28 insertions(+), 90 deletions(-)
diff --git a/drivers/leds/flash/Kconfig b/drivers/leds/flash/Kconfig
index 4e08dbc05709..a0fb755b58dc 100644
--- a/drivers/leds/flash/Kconfig
+++ b/drivers/leds/flash/Kconfig
@@ -23,7 +23,7 @@ config LEDS_AS3645A
config LEDS_KTD2692
tristate "LED support for Kinetic KTD2692 flash LED controller"
depends on OF
- depends on GPIOLIB || COMPILE_TEST
+ select LEDS_EXPRESSWIRE
help
This option enables support for Kinetic KTD2692 LED flash connected
through ExpressWire interface.
diff --git a/drivers/leds/flash/leds-ktd2692.c b/drivers/leds/flash/leds-ktd2692.c
index 598eee5daa52..7bb0aa2753e3 100644
--- a/drivers/leds/flash/leds-ktd2692.c
+++ b/drivers/leds/flash/leds-ktd2692.c
@@ -6,9 +6,9 @@
* Ingi Kim <ingi2.kim@samsung.com>
*/
-#include <linux/delay.h>
#include <linux/err.h>
#include <linux/gpio/consumer.h>
+#include <linux/leds-expresswire.h>
#include <linux/led-class-flash.h>
#include <linux/module.h>
#include <linux/mutex.h>
@@ -37,22 +37,9 @@
#define KTD2692_REG_FLASH_CURRENT_BASE 0x80
#define KTD2692_REG_MODE_BASE 0xA0
-/* Set bit coding time for expresswire interface */
-#define KTD2692_TIME_RESET_US 700
-#define KTD2692_TIME_DATA_START_TIME_US 10
-#define KTD2692_TIME_HIGH_END_OF_DATA_US 350
-#define KTD2692_TIME_LOW_END_OF_DATA_US 10
-#define KTD2692_TIME_SHORT_BITSET_US 4
-#define KTD2692_TIME_LONG_BITSET_US 12
-
/* KTD2692 default length of name */
#define KTD2692_NAME_LENGTH 20
-enum ktd2692_bitset {
- KTD2692_LOW = 0,
- KTD2692_HIGH,
-};
-
/* Movie / Flash Mode Control */
enum ktd2692_led_mode {
KTD2692_MODE_DISABLE = 0, /* default */
@@ -71,7 +58,19 @@ struct ktd2692_led_config_data {
enum led_brightness max_brightness;
};
+const struct expresswire_timing ktd2692_timing = {
+ .poweroff_us = 700,
+ .data_start_us = 10,
+ .end_of_data_low_us = 10,
+ .end_of_data_high_us = 350,
+ .short_bitset_us = 4,
+ .long_bitset_us = 12
+};
+
struct ktd2692_context {
+ /* Common ExpressWire properties (ctrl GPIO and timing) */
+ struct expresswire_common_props props;
+
/* Related LED Flash class device */
struct led_classdev_flash fled_cdev;
@@ -80,7 +79,6 @@ struct ktd2692_context {
struct regulator *regulator;
struct gpio_desc *aux_gpio;
- struct gpio_desc *ctrl_gpio;
enum ktd2692_led_mode mode;
enum led_brightness torch_brightness;
@@ -92,67 +90,6 @@ static struct ktd2692_context *fled_cdev_to_led(
return container_of(fled_cdev, struct ktd2692_context, fled_cdev);
}
-static void ktd2692_expresswire_start(struct ktd2692_context *led)
-{
- gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
- udelay(KTD2692_TIME_DATA_START_TIME_US);
-}
-
-static void ktd2692_expresswire_reset(struct ktd2692_context *led)
-{
- gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
- udelay(KTD2692_TIME_RESET_US);
-}
-
-static void ktd2692_expresswire_end(struct ktd2692_context *led)
-{
- gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
- udelay(KTD2692_TIME_LOW_END_OF_DATA_US);
- gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
- udelay(KTD2692_TIME_HIGH_END_OF_DATA_US);
-}
-
-static void ktd2692_expresswire_set_bit(struct ktd2692_context *led, bool bit)
-{
- /*
- * The Low Bit(0) and High Bit(1) is based on a time detection
- * algorithm between time low and time high
- * Time_(L_LB) : Low time of the Low Bit(0)
- * Time_(H_LB) : High time of the LOW Bit(0)
- * Time_(L_HB) : Low time of the High Bit(1)
- * Time_(H_HB) : High time of the High Bit(1)
- *
- * It can be simplified to:
- * Low Bit(0) : 2 * Time_(H_LB) < Time_(L_LB)
- * High Bit(1) : 2 * Time_(L_HB) < Time_(H_HB)
- * HIGH ___ ____ _.. _________ ___
- * |_________| |_.. |____| |__|
- * LOW <L_LB> <H_LB> <L_HB> <H_HB>
- * [ Low Bit (0) ] [ High Bit(1) ]
- */
- if (bit) {
- gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
- udelay(KTD2692_TIME_SHORT_BITSET_US);
- gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
- udelay(KTD2692_TIME_LONG_BITSET_US);
- } else {
- gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
- udelay(KTD2692_TIME_LONG_BITSET_US);
- gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
- udelay(KTD2692_TIME_SHORT_BITSET_US);
- }
-}
-
-static void ktd2692_expresswire_write(struct ktd2692_context *led, u8 value)
-{
- int i;
-
- ktd2692_expresswire_start(led);
- for (i = 7; i >= 0; i--)
- ktd2692_expresswire_set_bit(led, value & BIT(i));
- ktd2692_expresswire_end(led);
-}
-
static int ktd2692_led_brightness_set(struct led_classdev *led_cdev,
enum led_brightness brightness)
{
@@ -163,14 +100,14 @@ static int ktd2692_led_brightness_set(struct led_classdev *led_cdev,
if (brightness == LED_OFF) {
led->mode = KTD2692_MODE_DISABLE;
- gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
+ gpiod_direction_output(led->aux_gpio, 0);
} else {
- ktd2692_expresswire_write(led, brightness |
+ expresswire_write_u8(&led->props, brightness |
KTD2692_REG_MOVIE_CURRENT_BASE);
led->mode = KTD2692_MODE_MOVIE;
}
- ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);
+ expresswire_write_u8(&led->props, led->mode | KTD2692_REG_MODE_BASE);
mutex_unlock(&led->lock);
return 0;
@@ -187,17 +124,17 @@ static int ktd2692_led_flash_strobe_set(struct led_classdev_flash *fled_cdev,
if (state) {
flash_tm_reg = GET_TIMEOUT_OFFSET(timeout->val, timeout->step);
- ktd2692_expresswire_write(led, flash_tm_reg
+ expresswire_write_u8(&led->props, flash_tm_reg
| KTD2692_REG_FLASH_TIMEOUT_BASE);
led->mode = KTD2692_MODE_FLASH;
- gpiod_direction_output(led->aux_gpio, KTD2692_HIGH);
+ gpiod_direction_output(led->aux_gpio, 1);
} else {
led->mode = KTD2692_MODE_DISABLE;
- gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
+ gpiod_direction_output(led->aux_gpio, 0);
}
- ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);
+ expresswire_write_u8(&led->props, led->mode | KTD2692_REG_MODE_BASE);
fled_cdev->led_cdev.brightness = LED_OFF;
led->mode = KTD2692_MODE_DISABLE;
@@ -247,12 +184,12 @@ static void ktd2692_init_flash_timeout(struct led_classdev_flash *fled_cdev,
static void ktd2692_setup(struct ktd2692_context *led)
{
led->mode = KTD2692_MODE_DISABLE;
- ktd2692_expresswire_reset(led);
- gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
+ expresswire_power_off(&led->props);
+ gpiod_direction_output(led->aux_gpio, 0);
- ktd2692_expresswire_write(led, (KTD2692_MM_MIN_CURR_THRESHOLD_SCALE - 1)
+ expresswire_write_u8(&led->props, (KTD2692_MM_MIN_CURR_THRESHOLD_SCALE - 1)
| KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE);
- ktd2692_expresswire_write(led, KTD2692_FLASH_MODE_CURR_PERCENT(45)
+ expresswire_write_u8(&led->props, KTD2692_FLASH_MODE_CURR_PERCENT(45)
| KTD2692_REG_FLASH_CURRENT_BASE);
}
@@ -277,8 +214,8 @@ static int ktd2692_parse_dt(struct ktd2692_context *led, struct device *dev,
if (!np)
return -ENXIO;
- led->ctrl_gpio = devm_gpiod_get(dev, "ctrl", GPIOD_ASIS);
- ret = PTR_ERR_OR_ZERO(led->ctrl_gpio);
+ led->props.ctrl_gpio = devm_gpiod_get(dev, "ctrl", GPIOD_ASIS);
+ ret = PTR_ERR_OR_ZERO(led->props.ctrl_gpio);
if (ret)
return dev_err_probe(dev, ret, "cannot get ctrl-gpios\n");
@@ -412,6 +349,7 @@ static struct platform_driver ktd2692_driver = {
module_platform_driver(ktd2692_driver);
+MODULE_IMPORT_NS(EXPRESSWIRE);
MODULE_AUTHOR("Ingi Kim <ingi2.kim@samsung.com>");
MODULE_DESCRIPTION("Kinetic KTD2692 LED driver");
MODULE_LICENSE("GPL v2");
--
2.43.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v5 3/4] dt-bindings: backlight: add Kinetic KTD2801 binding
2024-01-25 15:30 [PATCH v5 0/4] Kinetic ExpressWire library and KTD2801 backlight driver Duje Mihanović
2024-01-25 15:30 ` [PATCH v5 1/4] leds: introduce ExpressWire library Duje Mihanović
2024-01-25 15:30 ` [PATCH v5 2/4] leds: ktd2692: convert to use " Duje Mihanović
@ 2024-01-25 15:30 ` Duje Mihanović
2024-01-25 15:30 ` [PATCH v5 4/4] backlight: Add Kinetic KTD2801 backlight support Duje Mihanović
2024-02-01 11:46 ` [PATCH v5 0/4] Kinetic ExpressWire library and KTD2801 backlight driver Lee Jones
4 siblings, 0 replies; 6+ messages in thread
From: Duje Mihanović @ 2024-01-25 15:30 UTC (permalink / raw
To: Lee Jones, Daniel Thompson, Jingoo Han, Pavel Machek, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Helge Deller, Linus Walleij
Cc: Karel Balej, ~postmarketos/upstreaming, phone-devel, dri-devel,
linux-leds, devicetree, linux-kernel, linux-fbdev,
Duje Mihanović, Krzysztof Kozlowski
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 <krzysztof.kozlowski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Duje Mihanović <duje.mihanovic@skole.hr>
---
.../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 <duje.mihanovic@skole.hr>
+
+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
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v5 4/4] backlight: Add Kinetic KTD2801 backlight support
2024-01-25 15:30 [PATCH v5 0/4] Kinetic ExpressWire library and KTD2801 backlight driver Duje Mihanović
` (2 preceding siblings ...)
2024-01-25 15:30 ` [PATCH v5 3/4] dt-bindings: backlight: add Kinetic KTD2801 binding Duje Mihanović
@ 2024-01-25 15:30 ` Duje Mihanović
2024-02-01 11:46 ` [PATCH v5 0/4] Kinetic ExpressWire library and KTD2801 backlight driver Lee Jones
4 siblings, 0 replies; 6+ messages in thread
From: Duje Mihanović @ 2024-01-25 15:30 UTC (permalink / raw
To: Lee Jones, Daniel Thompson, Jingoo Han, Pavel Machek, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Helge Deller, Linus Walleij
Cc: Karel Balej, ~postmarketos/upstreaming, phone-devel, dri-devel,
linux-leds, devicetree, linux-kernel, linux-fbdev,
Duje Mihanović
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 <linus.walleij@linaro.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Duje Mihanović <duje.mihanovic@skole.hr>
---
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 <duje.mihanovic@skole.hr>
+S: Maintained
+F: Documentation/devicetree/bindings/leds/backlight/kinetic,ktd2801.yaml
+F: drivers/video/backlight/ktd2801-backlight.c
+
KTEST
M: Steven Rostedt <rostedt@goodmis.org>
M: John Hawley <warthog9@eaglescrag.net>
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 <duje.mihanovic@skole.hr>");
+MODULE_DESCRIPTION("Kinetic KTD2801 Backlight Driver");
+MODULE_LICENSE("GPL");
--
2.43.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v5 0/4] Kinetic ExpressWire library and KTD2801 backlight driver
2024-01-25 15:30 [PATCH v5 0/4] Kinetic ExpressWire library and KTD2801 backlight driver Duje Mihanović
` (3 preceding siblings ...)
2024-01-25 15:30 ` [PATCH v5 4/4] backlight: Add Kinetic KTD2801 backlight support Duje Mihanović
@ 2024-02-01 11:46 ` Lee Jones
4 siblings, 0 replies; 6+ messages in thread
From: Lee Jones @ 2024-02-01 11:46 UTC (permalink / raw
To: Lee Jones, Daniel Thompson, Jingoo Han, Pavel Machek, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Helge Deller, Linus Walleij,
Duje Mihanović
Cc: Karel Balej, ~postmarketos/upstreaming, phone-devel, dri-devel,
linux-leds, devicetree, linux-kernel, linux-fbdev,
Krzysztof Kozlowski
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]
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2024-02-01 11:46 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2024-01-25 15:30 [PATCH v5 0/4] Kinetic ExpressWire library and KTD2801 backlight driver Duje Mihanović
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2024-01-25 15:30 ` [PATCH v5 2/4] leds: ktd2692: convert to use " Duje Mihanović
2024-01-25 15:30 ` [PATCH v5 3/4] dt-bindings: backlight: add Kinetic KTD2801 binding Duje Mihanović
2024-01-25 15:30 ` [PATCH v5 4/4] backlight: Add Kinetic KTD2801 backlight support Duje Mihanović
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