diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/input/joystick/walkera0701.c | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/drivers/input/joystick/walkera0701.c b/drivers/input/joystick/walkera0701.c new file mode 100644 index 000000000..56abc8c6c --- /dev/null +++ b/drivers/input/joystick/walkera0701.c @@ -0,0 +1,310 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Parallel port to Walkera WK-0701 TX joystick + * + * Copyright (c) 2008 Peter Popovec + * + * More about driver: <file:Documentation/input/devices/walkera0701.rst> + */ + + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#define RESERVE 20000 +#define SYNC_PULSE 1306000 +#define BIN0_PULSE 288000 +#define BIN1_PULSE 438000 + +#define ANALOG_MIN_PULSE 318000 +#define ANALOG_MAX_PULSE 878000 +#define ANALOG_DELTA 80000 + +#define BIN_SAMPLE ((BIN0_PULSE + BIN1_PULSE) / 2) + +#define NO_SYNC 25 + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/parport.h> +#include <linux/input.h> +#include <linux/hrtimer.h> + +MODULE_AUTHOR("Peter Popovec <popovec@fei.tuke.sk>"); +MODULE_DESCRIPTION("Walkera WK-0701 TX as joystick"); +MODULE_LICENSE("GPL"); + +static unsigned int walkera0701_pp_no; +module_param_named(port, walkera0701_pp_no, int, 0); +MODULE_PARM_DESC(port, + "Parallel port adapter for Walkera WK-0701 TX (default is 0)"); + +/* + * For now, only one device is supported, if somebody need more devices, code + * can be expanded, one struct walkera_dev per device must be allocated and + * set up by walkera0701_connect (release of device by walkera0701_disconnect) + */ + +struct walkera_dev { + unsigned char buf[25]; + u64 irq_time, irq_lasttime; + int counter; + int ack; + + struct input_dev *input_dev; + struct hrtimer timer; + + struct parport *parport; + struct pardevice *pardevice; +}; + +static struct walkera_dev w_dev; + +static inline void walkera0701_parse_frame(struct walkera_dev *w) +{ + int i; + int val1, val2, val3, val4, val5, val6, val7, val8; + int magic, magic_bit; + int crc1, crc2; + + for (crc1 = crc2 = i = 0; i < 10; i++) { + crc1 += w->buf[i] & 7; + crc2 += (w->buf[i] & 8) >> 3; + } + if ((w->buf[10] & 7) != (crc1 & 7)) + return; + if (((w->buf[10] & 8) >> 3) != (((crc1 >> 3) + crc2) & 1)) + return; + for (crc1 = crc2 = 0, i = 11; i < 23; i++) { + crc1 += w->buf[i] & 7; + crc2 += (w->buf[i] & 8) >> 3; + } + if ((w->buf[23] & 7) != (crc1 & 7)) + return; + if (((w->buf[23] & 8) >> 3) != (((crc1 >> 3) + crc2) & 1)) + return; + val1 = ((w->buf[0] & 7) * 256 + w->buf[1] * 16 + w->buf[2]) >> 2; + val1 *= ((w->buf[0] >> 2) & 2) - 1; /* sign */ + val2 = (w->buf[2] & 1) << 8 | (w->buf[3] << 4) | w->buf[4]; + val2 *= (w->buf[2] & 2) - 1; /* sign */ + val3 = ((w->buf[5] & 7) * 256 + w->buf[6] * 16 + w->buf[7]) >> 2; + val3 *= ((w->buf[5] >> 2) & 2) - 1; /* sign */ + val4 = (w->buf[7] & 1) << 8 | (w->buf[8] << 4) | w->buf[9]; + val4 *= (w->buf[7] & 2) - 1; /* sign */ + val5 = ((w->buf[11] & 7) * 256 + w->buf[12] * 16 + w->buf[13]) >> 2; + val5 *= ((w->buf[11] >> 2) & 2) - 1; /* sign */ + val6 = (w->buf[13] & 1) << 8 | (w->buf[14] << 4) | w->buf[15]; + val6 *= (w->buf[13] & 2) - 1; /* sign */ + val7 = ((w->buf[16] & 7) * 256 + w->buf[17] * 16 + w->buf[18]) >> 2; + val7 *= ((w->buf[16] >> 2) & 2) - 1; /*sign */ + val8 = (w->buf[18] & 1) << 8 | (w->buf[19] << 4) | w->buf[20]; + val8 *= (w->buf[18] & 2) - 1; /*sign */ + + magic = (w->buf[21] << 4) | w->buf[22]; + magic_bit = (w->buf[24] & 8) >> 3; + pr_debug("%4d %4d %4d %4d %4d %4d %4d %4d (magic %2x %d)\n", + val1, val2, val3, val4, val5, val6, val7, val8, + magic, magic_bit); + + input_report_abs(w->input_dev, ABS_X, val2); + input_report_abs(w->input_dev, ABS_Y, val1); + input_report_abs(w->input_dev, ABS_Z, val6); + input_report_abs(w->input_dev, ABS_THROTTLE, val3); + input_report_abs(w->input_dev, ABS_RUDDER, val4); + input_report_abs(w->input_dev, ABS_MISC, val7); + input_report_key(w->input_dev, BTN_GEAR_DOWN, val5 > 0); +} + +static inline int read_ack(struct pardevice *p) +{ + return parport_read_status(p->port) & 0x40; +} + +/* falling edge, prepare to BIN value calculation */ +static void walkera0701_irq_handler(void *handler_data) +{ + u64 pulse_time; + struct walkera_dev *w = handler_data; + + w->irq_time = ktime_to_ns(ktime_get()); + pulse_time = w->irq_time - w->irq_lasttime; + w->irq_lasttime = w->irq_time; + + /* cancel timer, if in handler or active do resync */ + if (unlikely(0 != hrtimer_try_to_cancel(&w->timer))) { + w->counter = NO_SYNC; + return; + } + + if (w->counter < NO_SYNC) { + if (w->ack) { + pulse_time -= BIN1_PULSE; + w->buf[w->counter] = 8; + } else { + pulse_time -= BIN0_PULSE; + w->buf[w->counter] = 0; + } + if (w->counter == 24) { /* full frame */ + walkera0701_parse_frame(w); + w->counter = NO_SYNC; + if (abs(pulse_time - SYNC_PULSE) < RESERVE) /* new frame sync */ + w->counter = 0; + } else { + if ((pulse_time > (ANALOG_MIN_PULSE - RESERVE) + && (pulse_time < (ANALOG_MAX_PULSE + RESERVE)))) { + pulse_time -= (ANALOG_MIN_PULSE - RESERVE); + pulse_time = (u32) pulse_time / ANALOG_DELTA; /* overtiping is safe, pulsetime < s32.. */ + w->buf[w->counter++] |= (pulse_time & 7); + } else + w->counter = NO_SYNC; + } + } else if (abs(pulse_time - SYNC_PULSE - BIN0_PULSE) < + RESERVE + BIN1_PULSE - BIN0_PULSE) /* frame sync .. */ + w->counter = 0; + + hrtimer_start(&w->timer, BIN_SAMPLE, HRTIMER_MODE_REL); +} + +static enum hrtimer_restart timer_handler(struct hrtimer + *handle) +{ + struct walkera_dev *w; + + w = container_of(handle, struct walkera_dev, timer); + w->ack = read_ack(w->pardevice); + + return HRTIMER_NORESTART; +} + +static int walkera0701_open(struct input_dev *dev) +{ + struct walkera_dev *w = input_get_drvdata(dev); + + if (parport_claim(w->pardevice)) + return -EBUSY; + + parport_enable_irq(w->parport); + return 0; +} + +static void walkera0701_close(struct input_dev *dev) +{ + struct walkera_dev *w = input_get_drvdata(dev); + + parport_disable_irq(w->parport); + hrtimer_cancel(&w->timer); + + parport_release(w->pardevice); +} + +static void walkera0701_attach(struct parport *pp) +{ + struct pardev_cb walkera0701_parport_cb; + struct walkera_dev *w = &w_dev; + + if (pp->number != walkera0701_pp_no) { + pr_debug("Not using parport%d.\n", pp->number); + return; + } + + if (pp->irq == -1) { + pr_err("parport %d does not have interrupt assigned\n", + pp->number); + return; + } + + w->parport = pp; + + memset(&walkera0701_parport_cb, 0, sizeof(walkera0701_parport_cb)); + walkera0701_parport_cb.flags = PARPORT_FLAG_EXCL; + walkera0701_parport_cb.irq_func = walkera0701_irq_handler; + walkera0701_parport_cb.private = w; + + w->pardevice = parport_register_dev_model(pp, "walkera0701", + &walkera0701_parport_cb, 0); + + if (!w->pardevice) { + pr_err("failed to register parport device\n"); + return; + } + + if (parport_negotiate(w->pardevice->port, IEEE1284_MODE_COMPAT)) { + pr_err("failed to negotiate parport mode\n"); + goto err_unregister_device; + } + + hrtimer_init(&w->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + w->timer.function = timer_handler; + + w->input_dev = input_allocate_device(); + if (!w->input_dev) { + pr_err("failed to allocate input device\n"); + goto err_unregister_device; + } + + input_set_drvdata(w->input_dev, w); + w->input_dev->name = "Walkera WK-0701 TX"; + w->input_dev->phys = w->parport->name; + w->input_dev->id.bustype = BUS_PARPORT; + + /* TODO what id vendor/product/version ? */ + w->input_dev->id.vendor = 0x0001; + w->input_dev->id.product = 0x0001; + w->input_dev->id.version = 0x0100; + w->input_dev->dev.parent = w->parport->dev; + w->input_dev->open = walkera0701_open; + w->input_dev->close = walkera0701_close; + + w->input_dev->evbit[0] = BIT(EV_ABS) | BIT_MASK(EV_KEY); + w->input_dev->keybit[BIT_WORD(BTN_GEAR_DOWN)] = BIT_MASK(BTN_GEAR_DOWN); + + input_set_abs_params(w->input_dev, ABS_X, -512, 512, 0, 0); + input_set_abs_params(w->input_dev, ABS_Y, -512, 512, 0, 0); + input_set_abs_params(w->input_dev, ABS_Z, -512, 512, 0, 0); + input_set_abs_params(w->input_dev, ABS_THROTTLE, -512, 512, 0, 0); + input_set_abs_params(w->input_dev, ABS_RUDDER, -512, 512, 0, 0); + input_set_abs_params(w->input_dev, ABS_MISC, -512, 512, 0, 0); + + if (input_register_device(w->input_dev)) { + pr_err("failed to register input device\n"); + goto err_free_input_dev; + } + + return; + +err_free_input_dev: + input_free_device(w->input_dev); +err_unregister_device: + parport_unregister_device(w->pardevice); +} + +static void walkera0701_detach(struct parport *port) +{ + struct walkera_dev *w = &w_dev; + + if (!w->pardevice || w->parport->number != port->number) + return; + + input_unregister_device(w->input_dev); + parport_unregister_device(w->pardevice); + w->parport = NULL; +} + +static struct parport_driver walkera0701_parport_driver = { + .name = "walkera0701", + .match_port = walkera0701_attach, + .detach = walkera0701_detach, + .devmodel = true, +}; + +static int __init walkera0701_init(void) +{ + return parport_register_driver(&walkera0701_parport_driver); +} + +static void __exit walkera0701_exit(void) +{ + parport_unregister_driver(&walkera0701_parport_driver); +} + +module_init(walkera0701_init); +module_exit(walkera0701_exit); |