/*
 * tslib/plugins/galax-raw.c
 *
 * Inspired from input-raw.c
 * 2009.05 Fred Salabartan
 *
 * Add support for version 0100 by Oskari Rauta <oskari.rauta@gmail.com> 2013
 * Modify by Jean-Baptiste Théou <jean-baptiste.theou@vodalys.com> (2013)
 *
 * This file is placed under the LGPL. Please see the file
 * COPYING for more details.
 *
 * SPDX-License-Identifier: LGPL-2.1
 *
 *
 * Plugin for "eGalax Inc. Touch" (using usbhid driver)
 * (Vendor=0eef Product=0001 Version=0112/210/0100)
 */

#include "config.h"

#include <errno.h>
#include <stdio.h>
#include <limits.h>
#include <stdint.h>

#include <stdlib.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <sys/time.h>
#include <sys/types.h>

#ifdef __FreeBSD__
#include <dev/evdev/input.h>
#else
#include <linux/input.h>
#endif
#ifndef EV_SYN /* 2.4 kernel headers */
# define EV_SYN 0x00
#endif
#ifndef EV_CNT
# define EV_CNT (EV_MAX+1)
#endif
#ifndef ABS_CNT
# define ABS_CNT (ABS_MAX+1)
#endif
#ifndef KEY_CNT
# define KEY_CNT (KEY_MAX+1)
#endif

#ifndef ABS_MT_DISTANCE /* < 2.6.38 kernel headers */
# define ABS_MT_DISTANCE         0x3b    /* Contact hover distance */
#endif

#include "tslib-private.h"

#define GRAB_EVENTS_WANTED  1
#define GRAB_EVENTS_ACTIVE  2

#define BITS_PER_BYTE	8
#define BITS_PER_LONG	(sizeof(long) * BITS_PER_BYTE)

#define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
#define BIT(nr) (1UL << (nr))
#define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
#define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_LONG)

#define VERSION_0112 1
#define VERSION_210  2
#define VERSION_0100 3
/* VERSION_210 must use /dev/input/event1 */


struct tslib_galax {
	struct tslib_module_info module;

	int current_x;
	int current_y;
	int current_p;
	int model_version;
	int sane_fd;
	int grab_events;
};




static int ts_galax_check_fd(struct tslib_galax *i)
{
	struct tsdev *ts = i->module.dev;
	int version;
	long evbit[BITS_TO_LONGS(EV_CNT)];
	long absbit[BITS_TO_LONGS(ABS_CNT)];
	long keybit[BITS_TO_LONGS(KEY_CNT)];
	struct input_id infos;

	if (ioctl(ts->fd, EVIOCGVERSION, &version) < 0) {
		fprintf(stderr,
			"tslib: Selected device is not a Linux input event device\n");
		return -1;
	}

	if (version < EV_VERSION) {
		fprintf(stderr,
			"tslib: Selected device uses a different version of the event protocol than tslib was compiled for\n");
		return -1;
	}

	if ((ioctl(ts->fd, EVIOCGID, &infos) < 0)) {
		fprintf(stderr, "tslib: warning, can not read device identifier\n");
	} else if (infos.bustype != 3 || infos.vendor != 0x0EEF ||
		   (infos.product != 0x0001 && infos.product != 0x7200 && infos.product != 0x7201)) {
		fprintf(stderr, "tslib: this is not an eGalax touchscreen (3,0x0EEF,1/7200/7201,0x0112)\n"
			"Your device: bus=%d, vendor=0x%X, product=0x%X, version=0x%X\n",
			infos.bustype, infos.vendor, infos.product, infos.version);
		return -1;
	}
	if (infos.version == 0x0112) {
		i->model_version = VERSION_0112;
	} else if (infos.version == 0x210) {
		i->model_version = VERSION_210;
	} else if (infos.version == 0x0100) {
		i->model_version = VERSION_0100;
	} else {
		fprintf(stderr, "Unsupported model\n");
		return -1;
	}

	if ((ioctl(ts->fd, EVIOCGBIT(0, sizeof(evbit)), evbit) < 0) ||
		!(evbit[BIT_WORD(EV_ABS)] & BIT_MASK(EV_ABS)) ||
		!(evbit[BIT_WORD(EV_KEY)] & BIT_MASK(EV_KEY))) {
		fprintf(stderr,
			"tslib: Selected device is not a touchscreen (must support ABS and KEY event types)\n");
		return -1;
	}

	if ((ioctl(ts->fd, EVIOCGBIT(EV_ABS, sizeof(absbit)), absbit)) < 0 ||
		!(absbit[BIT_WORD(ABS_X)] & BIT_MASK(ABS_X)) ||
		!(absbit[BIT_WORD(ABS_Y)] & BIT_MASK(ABS_Y))) {
		fprintf(stderr,
			"tslib: Selected device is not a touchscreen (must support ABS_X and ABS_Y events)\n");
		return -1;
	}

	/* Since some touchscreens (eg. infrared) physically can't measure pressure,
	 * the input system doesn't report it on those. Tslib relies on pressure, thus
	 * we set it to constant 255. It's still controlled by BTN_TOUCH - when not
	 * touched, the pressure is forced to 0.
	 */
	if (!(absbit[BIT_WORD(ABS_PRESSURE)] & BIT_MASK(ABS_PRESSURE))) {
		i->current_p = 255;

		if ((ioctl(ts->fd, EVIOCGBIT(EV_KEY, sizeof(keybit)), keybit) < 0) ||
			!(keybit[BIT_WORD(BTN_TOUCH)] & BIT_MASK(BTN_TOUCH) ||
			  keybit[BIT_WORD(BTN_LEFT)] & BIT_MASK(BTN_LEFT))) {
			fprintf(stderr,
				"tslib: Selected device is not a touchscreen (must support BTN_TOUCH or BTN_LEFT events)\n");
			return -1;
		}
	}

	if (!(evbit[BIT_WORD(EV_SYN)] & BIT_MASK(EV_SYN))) {
		fprintf(stderr, "tslib: device does not use EV_SYN\n");
		return -1;
	}

	if (i->grab_events == GRAB_EVENTS_WANTED) {
		if (ioctl(ts->fd, EVIOCGRAB, (void *)1)) {
			fprintf(stderr,
				"tslib: unable to grab selected input device\n");
			return -1;
		}
		i->grab_events = GRAB_EVENTS_ACTIVE;
	}

	return 0;
}

static int ts_galax_read(struct tslib_module_info *inf,
			 struct ts_sample *samp, int nr)
{
	struct tslib_galax *i = (struct tslib_galax *)inf;
	struct tsdev *ts = inf->dev;
	struct input_event ev;
	int ret = nr;
	int total = 0;

	if (i->sane_fd == 0)
		i->sane_fd = ts_galax_check_fd(i);

	if (i->sane_fd == -1)
		return 0;

	while (total < nr) {
		ret = read(ts->fd, &ev, sizeof(struct input_event));
		if (ret < (int)sizeof(struct input_event)) {
			total = -1;
			break;
		}

		switch (ev.type) {
		case EV_KEY:
			switch (ev.code) {
			case BTN_TOUCH:
				if (ev.value == 0) {
					/* pen up */
					i->current_x = 0;
					i->current_y = 0;
					i->current_p = 0;
				} else {
					i->current_p = 255;
				}
				break;
			}
			break;
		case EV_SYN:
			/* Fill out a new complete event */
			samp->x = i->current_x;
			samp->y = i->current_y;
			samp->pressure = i->current_p;
			samp->tv = ev.time;
			samp++;
			total++;
			break;

		case EV_ABS:
			if (i->model_version == VERSION_0112) {
				switch (ev.code) {
				case ABS_X+2: i->current_x = ev.value; break;
				case ABS_Y+2: i->current_y = ev.value; break;
				case ABS_PRESSURE: i->current_p = ev.value; break;
				}
			} else if (i->model_version == VERSION_210) {
				switch (ev.code) {
				case ABS_X: i->current_x = ev.value; break;
				case ABS_Y: i->current_y = ev.value; break;
				case ABS_PRESSURE: i->current_p = ev.value; break;
				case ABS_MT_DISTANCE:
					if (ev.value > 0)
						i->current_p = 0;
					else
						i->current_p = 255;

					break;
				}
			} else if (i->model_version == VERSION_0100) {
				switch (ev.code) {
				case ABS_X: i->current_x = ev.value; break;
				case ABS_Y: i->current_y = ev.value; break;
				case ABS_PRESSURE: i->current_p = ev.value; break;
				}
			}
			break;
		}
		ret = total;
	}
	return ret;
}

static int ts_galax_fini(struct tslib_module_info *inf)
{
	struct tslib_galax *i = (struct tslib_galax *)inf;
	struct tsdev *ts = inf->dev;

	if (i->grab_events == GRAB_EVENTS_ACTIVE) {
		if (ioctl(ts->fd, EVIOCGRAB, (void *)0)) {
			fprintf(stderr,
				"tslib: Unable to un-grab selected input device\n");
		}
	}

	free(inf);
	return 0;
}

static const struct tslib_ops __ts_galax_ops = {
	.read = ts_galax_read,
	.fini = ts_galax_fini,
};

static int parse_raw_grab(struct tslib_module_info *inf, char *str, void *data)
{
	struct tslib_galax *i = (struct tslib_galax *)inf;
	unsigned long v;
	int err = errno;

	v = strtoul(str, NULL, 0);

	if (v == ULONG_MAX && errno == ERANGE)
	return -1;

	errno = err;
	switch ((int)(intptr_t)data) {
	case 1:
		if (v)
			i->grab_events = GRAB_EVENTS_WANTED;
		break;
	default:
		return -1;
	}
	return 0;
}

static const struct tslib_vars raw_vars[] = {
	{ "grab_events", (void *)1, parse_raw_grab },
};

#define NR_VARS (sizeof(raw_vars) / sizeof(raw_vars[0]))


TSAPI struct tslib_module_info *galax_mod_init(__attribute__ ((unused)) struct tsdev *dev,
					       const char *params)
{
	struct tslib_galax *i;

	i = malloc(sizeof (struct tslib_galax));
	if (i == NULL)
		return NULL;

	i->module.ops = &__ts_galax_ops;
	i->current_x = 0;
	i->current_y = 0;
	i->current_p = 0;
	i->sane_fd = 0;
	i->grab_events = 0;

	if (tslib_parse_vars(&i->module, raw_vars, NR_VARS, params)) {
		free(i);
		return NULL;
	}

	return &(i->module);
}

#ifndef TSLIB_STATIC_GALAX_MODULE
	TSLIB_MODULE_INIT(galax_mod_init);
#endif