Link: https://lore.kernel.org/r/20260217200002.683975158@linuxfoundation.org Tested-by: Florian Fainelli <florian.fainelli@broadcom.com> Tested-by: Takeshi Ogasawara <takeshi.ogasawara@futuring-girl.com> Tested-by: Peter Schneider <pschneider1968@googlemail.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Salvatore Bonaccorso <carnil@debian.org> Tested-by: Brett A C Sheffield <bacs@librecast.net> Tested-by: Mark Brown <broonie@kernel.org> Tested-by: Luna Jernberg <droidbittin@gmail.com> Tested-by: Ronald Warsow <rwarsow@gmx.de> Tested-by: Justin M. Forbes <jforbes@fedoraproject.org> Tested-by: Ron Economos <re@w6rz.net> Tested-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
73 lines
2.2 KiB
C
73 lines
2.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Shared library for Kinetic's ExpressWire protocol.
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* This protocol works by pulsing the ExpressWire IC's control GPIO.
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* ktd2692 and ktd2801 are known to use this protocol.
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*/
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#include <linux/bits.h>
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#include <linux/delay.h>
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#include <linux/export.h>
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#include <linux/gpio/consumer.h>
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#include <linux/types.h>
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#include <linux/leds-expresswire.h>
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void expresswire_power_off(struct expresswire_common_props *props)
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{
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gpiod_set_value_cansleep(props->ctrl_gpio, 0);
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usleep_range(props->timing.poweroff_us, props->timing.poweroff_us * 2);
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}
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EXPORT_SYMBOL_NS_GPL(expresswire_power_off, "EXPRESSWIRE");
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void expresswire_enable(struct expresswire_common_props *props)
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{
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gpiod_set_value(props->ctrl_gpio, 1);
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udelay(props->timing.detect_delay_us);
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gpiod_set_value(props->ctrl_gpio, 0);
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udelay(props->timing.detect_us);
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gpiod_set_value(props->ctrl_gpio, 1);
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}
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EXPORT_SYMBOL_NS_GPL(expresswire_enable, "EXPRESSWIRE");
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void expresswire_start(struct expresswire_common_props *props)
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{
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gpiod_set_value(props->ctrl_gpio, 1);
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udelay(props->timing.data_start_us);
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}
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EXPORT_SYMBOL_NS_GPL(expresswire_start, "EXPRESSWIRE");
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void expresswire_end(struct expresswire_common_props *props)
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{
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gpiod_set_value(props->ctrl_gpio, 0);
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udelay(props->timing.end_of_data_low_us);
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gpiod_set_value(props->ctrl_gpio, 1);
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udelay(props->timing.end_of_data_high_us);
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}
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EXPORT_SYMBOL_NS_GPL(expresswire_end, "EXPRESSWIRE");
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void expresswire_set_bit(struct expresswire_common_props *props, bool bit)
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{
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if (bit) {
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gpiod_set_value(props->ctrl_gpio, 0);
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udelay(props->timing.short_bitset_us);
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gpiod_set_value(props->ctrl_gpio, 1);
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udelay(props->timing.long_bitset_us);
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} else {
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gpiod_set_value(props->ctrl_gpio, 0);
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udelay(props->timing.long_bitset_us);
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gpiod_set_value(props->ctrl_gpio, 1);
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udelay(props->timing.short_bitset_us);
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}
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}
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EXPORT_SYMBOL_NS_GPL(expresswire_set_bit, "EXPRESSWIRE");
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void expresswire_write_u8(struct expresswire_common_props *props, u8 val)
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{
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expresswire_start(props);
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for (int i = 7; i >= 0; i--)
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expresswire_set_bit(props, val & BIT(i));
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expresswire_end(props);
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}
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EXPORT_SYMBOL_NS_GPL(expresswire_write_u8, "EXPRESSWIRE");
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