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 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 (3):
leds: ktd2692: move ExpressWire code to 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: 0dd3ee31125508cd67f7e7172247f05b7fd1753a
change-id: 20231004-ktd2801-0f3883cb59d0
Best regards,
--
Duje Mihanović <[email protected]>
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 move it into
a library in preparation for adding KTD2801 support.
Suggested-by: Daniel Thompson <[email protected]>
Reviewed-by: Linus Walleij <[email protected]>
Signed-off-by: Duje Mihanović <[email protected]>
---
MAINTAINERS | 7 +++
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 ++++++++++++++++++++++
include/linux/leds-expresswire.h | 36 ++++++++++++
7 files changed, 146 insertions(+), 90 deletions(-)
diff --git a/MAINTAINERS b/MAINTAINERS
index a7c4cf8201e0..87b12d2448a0 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7902,6 +7902,13 @@ 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 <[email protected]>
+L: [email protected]
+S: Maintained
+F: drivers/leds/leds-expresswire.c
+F: include/linux/leds-expresswire.h
+
EXT2 FILE SYSTEM
M: Jan Kara <[email protected]>
L: [email protected]
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 6292fddcc55c..15e1c3c238ab 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -181,6 +181,10 @@ 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 d7348e8bc019..a63a07d01c6f 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -89,6 +89,9 @@ 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/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 <[email protected]>
*/
-#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 <[email protected]>");
MODULE_DESCRIPTION("Kinetic KTD2692 LED driver");
MODULE_LICENSE("GPL v2");
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
On Mon, Jan 22, 2024 at 08:50:57PM +0100, Duje Mihanović wrote:
> 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 move it into
> a library in preparation for adding KTD2801 support.
>
> Suggested-by: Daniel Thompson <[email protected]>
> Reviewed-by: Linus Walleij <[email protected]>
> Signed-off-by: Duje Mihanović <[email protected]>
Reviewed-by: Daniel Thompson <[email protected]>
Daniel.
On Mon, 22 Jan 2024, Duje Mihanović wrote:
> 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 move it into
> a library in preparation for adding KTD2801 support.
>
> Suggested-by: Daniel Thompson <[email protected]>
> Reviewed-by: Linus Walleij <[email protected]>
> Signed-off-by: Duje Mihanović <[email protected]>
> ---
> MAINTAINERS | 7 +++
> 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 ++++++++++++++++++++++
> include/linux/leds-expresswire.h | 36 ++++++++++++
Please can you separate the Expresswire addition into its own patch?
> 7 files changed, 146 insertions(+), 90 deletions(-)
--
Lee Jones [李琼斯]