[deliverable/linux.git] / drivers / input / joystick / walkera0701.c

/*
 *  Parallel port to Walkera WK-0701 TX joystick
 *
 *  Copyright (c) 2008 Peter Popovec
 *
 *  More about driver:  <file:Documentation/input/walkera0701.txt>
 */

/*
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
*/

#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, ktime_set(0, 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);
Commit	Line	Data
cec87e38 PP	1	/*
	2	* Parallel port to Walkera WK-0701 TX joystick
	3	*
	4	* Copyright (c) 2008 Peter Popovec
	5	*
	6	* More about driver: <file:Documentation/input/walkera0701.txt>
	7	*/
	8
	9	/*
	10	* This program is free software; you can redistribute it and/or modify it
	11	* under the terms of the GNU General Public License version 2 as published by
	12	* the Free Software Foundation.
	13	*/
	14
e0dba55e	15	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
cec87e38 PP	16
	17	#define RESERVE 20000
	18	#define SYNC_PULSE 1306000
	19	#define BIN0_PULSE 288000
	20	#define BIN1_PULSE 438000
	21
	22	#define ANALOG_MIN_PULSE 318000
	23	#define ANALOG_MAX_PULSE 878000
	24	#define ANALOG_DELTA 80000
	25
	26	#define BIN_SAMPLE ((BIN0_PULSE + BIN1_PULSE) / 2)
	27
	28	#define NO_SYNC 25
	29
	30	#include <linux/kernel.h>
	31	#include <linux/module.h>
	32	#include <linux/parport.h>
	33	#include <linux/input.h>
	34	#include <linux/hrtimer.h>
	35
	36	MODULE_AUTHOR("Peter Popovec <popovec@fei.tuke.sk>");
	37	MODULE_DESCRIPTION("Walkera WK-0701 TX as joystick");
	38	MODULE_LICENSE("GPL");
	39
	40	static unsigned int walkera0701_pp_no;
	41	module_param_named(port, walkera0701_pp_no, int, 0);
	42	MODULE_PARM_DESC(port,
	43	"Parallel port adapter for Walkera WK-0701 TX (default is 0)");
	44
	45	/*
	46	* For now, only one device is supported, if somebody need more devices, code
	47	* can be expanded, one struct walkera_dev per device must be allocated and
	48	* set up by walkera0701_connect (release of device by walkera0701_disconnect)
	49	*/
	50
	51	struct walkera_dev {
	52	unsigned char buf[25];
	53	u64 irq_time, irq_lasttime;
	54	int counter;
	55	int ack;
	56
	57	struct input_dev *input_dev;
	58	struct hrtimer timer;
	59
	60	struct parport *parport;
	61	struct pardevice *pardevice;
	62	};
	63
	64	static struct walkera_dev w_dev;
	65
	66	static inline void walkera0701_parse_frame(struct walkera_dev *w)
	67	{
	68	int i;
	69	int val1, val2, val3, val4, val5, val6, val7, val8;
e0dba55e	70	int magic, magic_bit;
cec87e38 PP	71	int crc1, crc2;
	72
	73	for (crc1 = crc2 = i = 0; i < 10; i++) {
	74	crc1 += w->buf[i] & 7;
	75	crc2 += (w->buf[i] & 8) >> 3;
	76	}
	77	if ((w->buf[10] & 7) != (crc1 & 7))
	78	return;
	79	if (((w->buf[10] & 8) >> 3) != (((crc1 >> 3) + crc2) & 1))
	80	return;
	81	for (crc1 = crc2 = 0, i = 11; i < 23; i++) {
	82	crc1 += w->buf[i] & 7;
	83	crc2 += (w->buf[i] & 8) >> 3;
	84	}
	85	if ((w->buf[23] & 7) != (crc1 & 7))
	86	return;
	87	if (((w->buf[23] & 8) >> 3) != (((crc1 >> 3) + crc2) & 1))
	88	return;
	89	val1 = ((w->buf[0] & 7) * 256 + w->buf[1] * 16 + w->buf[2]) >> 2;
	90	val1 = ((w->buf[0] >> 2) & 2) - 1; / sign */
	91	val2 = (w->buf[2] & 1) << 8 \| (w->buf[3] << 4) \| w->buf[4];
	92	val2 = (w->buf[2] & 2) - 1; / sign */
	93	val3 = ((w->buf[5] & 7) * 256 + w->buf[6] * 16 + w->buf[7]) >> 2;
	94	val3 = ((w->buf[5] >> 2) & 2) - 1; / sign */
	95	val4 = (w->buf[7] & 1) << 8 \| (w->buf[8] << 4) \| w->buf[9];
	96	val4 = (w->buf[7] & 2) - 1; / sign */
	97	val5 = ((w->buf[11] & 7) * 256 + w->buf[12] * 16 + w->buf[13]) >> 2;
	98	val5 = ((w->buf[11] >> 2) & 2) - 1; / sign */
	99	val6 = (w->buf[13] & 1) << 8 \| (w->buf[14] << 4) \| w->buf[15];
	100	val6 = (w->buf[13] & 2) - 1; / sign */
	101	val7 = ((w->buf[16] & 7) * 256 + w->buf[17] * 16 + w->buf[18]) >> 2;
	102	val7 = ((w->buf[16] >> 2) & 2) - 1; /sign */
	103	val8 = (w->buf[18] & 1) << 8 \| (w->buf[19] << 4) \| w->buf[20];
	104	val8 = (w->buf[18] & 2) - 1; /sign */
	105
e0dba55e DT	106	magic = (w->buf[21] << 4) \| w->buf[22];
	107	magic_bit = (w->buf[24] & 8) >> 3;
	108	pr_debug("%4d %4d %4d %4d %4d %4d %4d %4d (magic %2x %d)\n",
	109	val1, val2, val3, val4, val5, val6, val7, val8,
	110	magic, magic_bit);
	111
cec87e38 PP	112	input_report_abs(w->input_dev, ABS_X, val2);
	113	input_report_abs(w->input_dev, ABS_Y, val1);
	114	input_report_abs(w->input_dev, ABS_Z, val6);
	115	input_report_abs(w->input_dev, ABS_THROTTLE, val3);
	116	input_report_abs(w->input_dev, ABS_RUDDER, val4);
	117	input_report_abs(w->input_dev, ABS_MISC, val7);
	118	input_report_key(w->input_dev, BTN_GEAR_DOWN, val5 > 0);
	119	}
	120
	121	static inline int read_ack(struct pardevice *p)
	122	{
	123	return parport_read_status(p->port) & 0x40;
	124	}
	125
	126	/* falling edge, prepare to BIN value calculation */
	127	static void walkera0701_irq_handler(void *handler_data)
	128	{
	129	u64 pulse_time;
	130	struct walkera_dev *w = handler_data;
	131
	132	w->irq_time = ktime_to_ns(ktime_get());
	133	pulse_time = w->irq_time - w->irq_lasttime;
	134	w->irq_lasttime = w->irq_time;
	135
	136	/* cancel timer, if in handler or active do resync */
	137	if (unlikely(0 != hrtimer_try_to_cancel(&w->timer))) {
	138	w->counter = NO_SYNC;
	139	return;
	140	}
	141
	142	if (w->counter < NO_SYNC) {
	143	if (w->ack) {
	144	pulse_time -= BIN1_PULSE;
	145	w->buf[w->counter] = 8;
	146	} else {
	147	pulse_time -= BIN0_PULSE;
	148	w->buf[w->counter] = 0;
	149	}
	150	if (w->counter == 24) { /* full frame */
	151	walkera0701_parse_frame(w);
	152	w->counter = NO_SYNC;
79211c8e	153	if (abs(pulse_time - SYNC_PULSE) < RESERVE) /* new frame sync */
cec87e38 PP	154	w->counter = 0;
	155	} else {
	156	if ((pulse_time > (ANALOG_MIN_PULSE - RESERVE)
	157	&& (pulse_time < (ANALOG_MAX_PULSE + RESERVE)))) {
	158	pulse_time -= (ANALOG_MIN_PULSE - RESERVE);
	159	pulse_time = (u32) pulse_time / ANALOG_DELTA; /* overtiping is safe, pulsetime < s32.. */
	160	w->buf[w->counter++] \|= (pulse_time & 7);
	161	} else
	162	w->counter = NO_SYNC;
	163	}
79211c8e	164	} else if (abs(pulse_time - SYNC_PULSE - BIN0_PULSE) <
cec87e38 PP	165	RESERVE + BIN1_PULSE - BIN0_PULSE) /* frame sync .. */
	166	w->counter = 0;
	167
	168	hrtimer_start(&w->timer, ktime_set(0, BIN_SAMPLE), HRTIMER_MODE_REL);
	169	}
	170
	171	static enum hrtimer_restart timer_handler(struct hrtimer
	172	*handle)
	173	{
	174	struct walkera_dev *w;
	175
	176	w = container_of(handle, struct walkera_dev, timer);
	177	w->ack = read_ack(w->pardevice);
	178
	179	return HRTIMER_NORESTART;
	180	}
	181
	182	static int walkera0701_open(struct input_dev *dev)
	183	{
	184	struct walkera_dev *w = input_get_drvdata(dev);
	185
cb696e7c DT	186	if (parport_claim(w->pardevice))
	187	return -EBUSY;
	188
cec87e38 PP	189	parport_enable_irq(w->parport);
	190	return 0;
	191	}
	192
	193	static void walkera0701_close(struct input_dev *dev)
	194	{
	195	struct walkera_dev *w = input_get_drvdata(dev);
	196
	197	parport_disable_irq(w->parport);
a455e298	198	hrtimer_cancel(&w->timer);
cb696e7c DT	199
cb696e7c DT	200	parport_release(w->pardevice);
cec87e38 PP	201	}
cec87e38 PP	202
221bcb24	203	static void walkera0701_attach(struct parport *pp)
cec87e38	204	{
221bcb24 SM	205	struct pardev_cb walkera0701_parport_cb;
221bcb24 SM	206	struct walkera_dev *w = &w_dev;
cec87e38	207
221bcb24 SM	208	if (pp->number != walkera0701_pp_no) {
	209	pr_debug("Not using parport%d.\n", pp->number);
	210	return;
ea05ae07	211	}
cec87e38	212
221bcb24	213	if (pp->irq == -1) {
e0dba55e	214	pr_err("parport %d does not have interrupt assigned\n",
221bcb24 SM	215	pp->number);
221bcb24 SM	216	return;
cec87e38 PP	217	}
cec87e38 PP	218
221bcb24 SM	219	w->parport = pp;
221bcb24 SM	220
d1f2a031	221	memset(&walkera0701_parport_cb, 0, sizeof(walkera0701_parport_cb));
221bcb24 SM	222	walkera0701_parport_cb.flags = PARPORT_FLAG_EXCL;
	223	walkera0701_parport_cb.irq_func = walkera0701_irq_handler;
	224	walkera0701_parport_cb.private = w;
	225
	226	w->pardevice = parport_register_dev_model(pp, "walkera0701",
	227	&walkera0701_parport_cb, 0);
	228
ea05ae07 DT	229	if (!w->pardevice) {
ea05ae07 DT	230	pr_err("failed to register parport device\n");
221bcb24	231	return;
ea05ae07	232	}
cec87e38	233
ea05ae07 DT	234	if (parport_negotiate(w->pardevice->port, IEEE1284_MODE_COMPAT)) {
ea05ae07 DT	235	pr_err("failed to negotiate parport mode\n");
ea05ae07 DT	236	goto err_unregister_device;
ea05ae07 DT	237	}
cec87e38	238
a455e298 PP	239	hrtimer_init(&w->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
	240	w->timer.function = timer_handler;
	241
cec87e38	242	w->input_dev = input_allocate_device();
ea05ae07 DT	243	if (!w->input_dev) {
ea05ae07 DT	244	pr_err("failed to allocate input device\n");
cb696e7c	245	goto err_unregister_device;
ea05ae07	246	}
cec87e38 PP	247
	248	input_set_drvdata(w->input_dev, w);
	249	w->input_dev->name = "Walkera WK-0701 TX";
	250	w->input_dev->phys = w->parport->name;
	251	w->input_dev->id.bustype = BUS_PARPORT;
	252
	253	/* TODO what id vendor/product/version ? */
	254	w->input_dev->id.vendor = 0x0001;
	255	w->input_dev->id.product = 0x0001;
	256	w->input_dev->id.version = 0x0100;
1932c8a0	257	w->input_dev->dev.parent = w->parport->dev;
cec87e38 PP	258	w->input_dev->open = walkera0701_open;
	259	w->input_dev->close = walkera0701_close;
	260
	261	w->input_dev->evbit[0] = BIT(EV_ABS) \| BIT_MASK(EV_KEY);
	262	w->input_dev->keybit[BIT_WORD(BTN_GEAR_DOWN)] = BIT_MASK(BTN_GEAR_DOWN);
	263
	264	input_set_abs_params(w->input_dev, ABS_X, -512, 512, 0, 0);
	265	input_set_abs_params(w->input_dev, ABS_Y, -512, 512, 0, 0);
	266	input_set_abs_params(w->input_dev, ABS_Z, -512, 512, 0, 0);
	267	input_set_abs_params(w->input_dev, ABS_THROTTLE, -512, 512, 0, 0);
	268	input_set_abs_params(w->input_dev, ABS_RUDDER, -512, 512, 0, 0);
	269	input_set_abs_params(w->input_dev, ABS_MISC, -512, 512, 0, 0);
	270
221bcb24	271	if (input_register_device(w->input_dev)) {
ea05ae07 DT	272	pr_err("failed to register input device\n");
	273	goto err_free_input_dev;
	274	}
cec87e38	275
221bcb24	276	return;
cec87e38	277
ea05ae07	278	err_free_input_dev:
cec87e38	279	input_free_device(w->input_dev);
ea05ae07	280	err_unregister_device:
cec87e38	281	parport_unregister_device(w->pardevice);
cec87e38 PP	282	}
cec87e38 PP	283
221bcb24	284	static void walkera0701_detach(struct parport *port)
cec87e38	285	{
221bcb24 SM	286	struct walkera_dev *w = &w_dev;
	287
	288	if (!w->pardevice \|\| w->parport->number != port->number)
	289	return;
	290
cec87e38	291	input_unregister_device(w->input_dev);
cec87e38	292	parport_unregister_device(w->pardevice);
221bcb24	293	w->parport = NULL;
cec87e38 PP	294	}
cec87e38 PP	295
221bcb24 SM	296	static struct parport_driver walkera0701_parport_driver = {
	297	.name = "walkera0701",
	298	.match_port = walkera0701_attach,
	299	.detach = walkera0701_detach,
	300	.devmodel = true,
	301	};
	302
cec87e38 PP	303	static int __init walkera0701_init(void)
cec87e38 PP	304	{
221bcb24	305	return parport_register_driver(&walkera0701_parport_driver);
cec87e38 PP	306	}
	307
	308	static void __exit walkera0701_exit(void)
	309	{
221bcb24	310	parport_unregister_driver(&walkera0701_parport_driver);
cec87e38 PP	311	}
	312
	313	module_init(walkera0701_init);
	314	module_exit(walkera0701_exit);