phone/src/pins/gpio-helpers.ts
2025-11-19 13:00:39 -08:00

102 lines
3.0 KiB
TypeScript

import type { Pointer } from "bun:ffi"
import { gpiod, GPIOD_LINE_DIRECTION_INPUT, GPIOD_LINE_DIRECTION_OUTPUT } from "./ffi"
import { cstr, mapPullToLibgpiod, mapEdgeToLibgpiod } from "./utils"
import type { PullMode, EdgeMode } from "./types"
type LineRequestResult = {
chip: Pointer
request: Pointer
}
export type InputLineConfig = {
chipPath: string
offset: number
pull: PullMode
debounce: number
edge: EdgeMode
}
export type OutputLineConfig = {
chipPath: string
offset: number
initialValue: 0 | 1
}
const cleanup = (message: string): never => {
throw new Error(message)
}
const requestLine = (
chipPath: string,
offset: number,
consumer: string,
configureSettings: (settings: Pointer) => void
): LineRequestResult => {
const chip = gpiod.gpiod_chip_open(cstr(chipPath))
if (!chip) cleanup("Failed to open GPIO chip")
const settings = gpiod.gpiod_line_settings_new()
if (!settings) {
gpiod.gpiod_chip_close(chip)
cleanup("Failed to create line settings")
}
configureSettings(settings!)
const lineConfig = gpiod.gpiod_line_config_new()
if (!lineConfig) {
gpiod.gpiod_line_settings_free(settings)
gpiod.gpiod_chip_close(chip)
cleanup("Failed to create line config")
}
const offsets = new Uint32Array([offset])
const ret = gpiod.gpiod_line_config_add_line_settings(lineConfig, offsets, 1, settings)
gpiod.gpiod_line_settings_free(settings)
if (ret !== 0) {
gpiod.gpiod_line_config_free(lineConfig)
gpiod.gpiod_chip_close(chip)
cleanup("Failed to add line settings")
}
const requestConfig = gpiod.gpiod_request_config_new()
if (!requestConfig) {
gpiod.gpiod_line_config_free(lineConfig)
gpiod.gpiod_chip_close(chip)
cleanup("Failed to create request config")
}
gpiod.gpiod_request_config_set_consumer(requestConfig, cstr(consumer))
const request = gpiod.gpiod_chip_request_lines(chip, requestConfig, lineConfig)
gpiod.gpiod_request_config_free(requestConfig)
gpiod.gpiod_line_config_free(lineConfig)
if (!request) {
gpiod.gpiod_chip_close(chip)
cleanup("Failed to request GPIO line")
}
return { chip: chip!, request: request! }
}
export const requestInputLine = (config: InputLineConfig): LineRequestResult => {
return requestLine(config.chipPath, config.offset, "bun-gpio-input", (settings) => {
gpiod.gpiod_line_settings_set_direction(settings, GPIOD_LINE_DIRECTION_INPUT)
gpiod.gpiod_line_settings_set_bias(settings, mapPullToLibgpiod(config.pull))
gpiod.gpiod_line_settings_set_edge_detection(settings, mapEdgeToLibgpiod(config.edge))
if (config.debounce > 0) {
gpiod.gpiod_line_settings_set_debounce_period_us(settings, config.debounce * 1000)
}
})
}
export const requestOutputLine = (config: OutputLineConfig): LineRequestResult => {
return requestLine(config.chipPath, config.offset, "bun-gpio", (settings) => {
gpiod.gpiod_line_settings_set_direction(settings, GPIOD_LINE_DIRECTION_OUTPUT)
gpiod.gpiod_line_settings_set_output_value(settings, config.initialValue)
})
}