From 1368d06dd2c99186174290c03d79c132db16efe2 Mon Sep 17 00:00:00 2001 From: Duje Mihanović Date: Thu, 25 Jan 2024 16:30:53 +0100 Subject: leds: Introduce ExpressWire library MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Linus Walleij Reviewed-by: Daniel Thompson Signed-off-by: Duje Mihanović Link: https://lore.kernel.org/r/20240125-ktd2801-v5-1-e22da232a825@skole.hr Signed-off-by: Lee Jones --- 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(+) create mode 100644 drivers/leds/leds-expresswire.c create mode 100644 include/linux/leds-expresswire.h 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 +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 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 +#include +#include + +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 + +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 */ -- cgit