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