projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 1368d06d DM |
1 | // SPDX-License-Identifier: GPL-2.0-only |
| 2 | /* | |
| 3 | * Shared library for Kinetic's ExpressWire protocol. | |
| 4 | * This protocol works by pulsing the ExpressWire IC's control GPIO. | |
| 5 | * ktd2692 and ktd2801 are known to use this protocol. | |
| 6 | */ | |
| 7 | ||
| 7774f3d1 | 8 | #include <linux/bits.h> |
| 1368d06d | 9 | #include <linux/delay.h> |
| 7774f3d1 | 10 | #include <linux/export.h> |
| 1368d06d | 11 | #include <linux/gpio/consumer.h> |
| 7774f3d1 AS |
12 | #include <linux/types.h> |
| 13 | ||
| 1368d06d DM |
14 | #include <linux/leds-expresswire.h> |
| 15 | ||
| 16 | void expresswire_power_off(struct expresswire_common_props *props) | |
| 17 | { | |
| 18 | gpiod_set_value_cansleep(props->ctrl_gpio, 0); | |
| 19 | usleep_range(props->timing.poweroff_us, props->timing.poweroff_us * 2); | |
| 20 | } | |
| 21 | EXPORT_SYMBOL_NS_GPL(expresswire_power_off, EXPRESSWIRE); | |
| 22 | ||
| 23 | void expresswire_enable(struct expresswire_common_props *props) | |
| 24 | { | |
| 25 | gpiod_set_value(props->ctrl_gpio, 1); | |
| 26 | udelay(props->timing.detect_delay_us); | |
| 27 | gpiod_set_value(props->ctrl_gpio, 0); | |
| 28 | udelay(props->timing.detect_us); | |
| 29 | gpiod_set_value(props->ctrl_gpio, 1); | |
| 30 | } | |
| 31 | EXPORT_SYMBOL_NS_GPL(expresswire_enable, EXPRESSWIRE); | |
| 32 | ||
| 33 | void expresswire_start(struct expresswire_common_props *props) | |
| 34 | { | |
| 35 | gpiod_set_value(props->ctrl_gpio, 1); | |
| 36 | udelay(props->timing.data_start_us); | |
| 37 | } | |
| 38 | EXPORT_SYMBOL_NS_GPL(expresswire_start, EXPRESSWIRE); | |
| 39 | ||
| 40 | void expresswire_end(struct expresswire_common_props *props) | |
| 41 | { | |
| 42 | gpiod_set_value(props->ctrl_gpio, 0); | |
| 43 | udelay(props->timing.end_of_data_low_us); | |
| 44 | gpiod_set_value(props->ctrl_gpio, 1); | |
| 45 | udelay(props->timing.end_of_data_high_us); | |
| 46 | } | |
| 47 | EXPORT_SYMBOL_NS_GPL(expresswire_end, EXPRESSWIRE); | |
| 48 | ||
| 49 | void expresswire_set_bit(struct expresswire_common_props *props, bool bit) | |
| 50 | { | |
| 51 | if (bit) { | |
| 52 | gpiod_set_value(props->ctrl_gpio, 0); | |
| 53 | udelay(props->timing.short_bitset_us); | |
| 54 | gpiod_set_value(props->ctrl_gpio, 1); | |
| 55 | udelay(props->timing.long_bitset_us); | |
| 56 | } else { | |
| 57 | gpiod_set_value(props->ctrl_gpio, 0); | |
| 58 | udelay(props->timing.long_bitset_us); | |
| 59 | gpiod_set_value(props->ctrl_gpio, 1); | |
| 60 | udelay(props->timing.short_bitset_us); | |
| 61 | } | |
| 62 | } | |
| 63 | EXPORT_SYMBOL_NS_GPL(expresswire_set_bit, EXPRESSWIRE); | |
| 64 | ||
| 65 | void expresswire_write_u8(struct expresswire_common_props *props, u8 val) | |
| 66 | { | |
| 67 | expresswire_start(props); | |
| 68 | for (int i = 7; i >= 0; i--) | |
| 69 | expresswire_set_bit(props, val & BIT(i)); | |
| 70 | expresswire_end(props); | |
| 71 | } | |
| 72 | EXPORT_SYMBOL_NS_GPL(expresswire_write_u8, EXPRESSWIRE); |