@@ -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 <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
@@ -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
@@ -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
@@ -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.
@@ -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");
new file mode 100644
@@ -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);
new file mode 100644
@@ -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 */