psmouse-base.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * PS/2 mouse driver
 *
 * Copyright (c) 1999-2002 Vojtech Pavlik
 * Copyright (c) 2003-2004 Dmitry Torokhov
 */


#define pr_fmt(fmt)		KBUILD_MODNAME ": " fmt
#define psmouse_fmt(fmt)	fmt

#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/input.h>
#include <linux/serio.h>
#include <linux/init.h>
#include <linux/libps2.h>
#include <linux/mutex.h>
#include <linux/types.h>

#include "psmouse.h"
#include "synaptics.h"
#include "logips2pp.h"
#include "alps.h"
#include "hgpk.h"
#include "lifebook.h"
#include "trackpoint.h"
#include "touchkit_ps2.h"
#include "elantech.h"
#include "sentelic.h"
#include "cypress_ps2.h"
#include "focaltech.h"
#include "vmmouse.h"
#include "byd.h"

#define DRIVER_DESC	"PS/2 mouse driver"

MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

static unsigned int psmouse_max_proto = PSMOUSE_AUTO;
static int psmouse_set_maxproto(const char *val, const struct kernel_param *);
static int psmouse_get_maxproto(char *buffer, const struct kernel_param *kp);
static const struct kernel_param_ops param_ops_proto_abbrev = {
	.set = psmouse_set_maxproto,
	.get = psmouse_get_maxproto,
};
#define param_check_proto_abbrev(name, p)	__param_check(name, p, unsigned int)
module_param_named(proto, psmouse_max_proto, proto_abbrev, 0644);
MODULE_PARM_DESC(proto, "Highest protocol extension to probe (bare, imps, exps, any). Useful for KVM switches.");

static unsigned int psmouse_resolution = 200;
module_param_named(resolution, psmouse_resolution, uint, 0644);
MODULE_PARM_DESC(resolution, "Resolution, in dpi.");

static unsigned int psmouse_rate = 100;
module_param_named(rate, psmouse_rate, uint, 0644);
MODULE_PARM_DESC(rate, "Report rate, in reports per second.");

static bool psmouse_smartscroll = true;
module_param_named(smartscroll, psmouse_smartscroll, bool, 0644);
MODULE_PARM_DESC(smartscroll, "Logitech Smartscroll autorepeat, 1 = enabled (default), 0 = disabled.");

static bool psmouse_a4tech_2wheels;
module_param_named(a4tech_workaround, psmouse_a4tech_2wheels, bool, 0644);
MODULE_PARM_DESC(a4tech_workaround, "A4Tech second scroll wheel workaround, 1 = enabled, 0 = disabled (default).");

static unsigned int psmouse_resetafter = 5;
module_param_named(resetafter, psmouse_resetafter, uint, 0644);
MODULE_PARM_DESC(resetafter, "Reset device after so many bad packets (0 = never).");

static unsigned int psmouse_resync_time;
module_param_named(resync_time, psmouse_resync_time, uint, 0644);
MODULE_PARM_DESC(resync_time, "How long can mouse stay idle before forcing resync (in seconds, 0 = never).");

PSMOUSE_DEFINE_ATTR(protocol, S_IWUSR | S_IRUGO,
			NULL,
			psmouse_attr_show_protocol, psmouse_attr_set_protocol);
PSMOUSE_DEFINE_ATTR(rate, S_IWUSR | S_IRUGO,
			(void *) offsetof(struct psmouse, rate),
			psmouse_show_int_attr, psmouse_attr_set_rate);
PSMOUSE_DEFINE_ATTR(resolution, S_IWUSR | S_IRUGO,
			(void *) offsetof(struct psmouse, resolution),
			psmouse_show_int_attr, psmouse_attr_set_resolution);
PSMOUSE_DEFINE_ATTR(resetafter, S_IWUSR | S_IRUGO,
			(void *) offsetof(struct psmouse, resetafter),
			psmouse_show_int_attr, psmouse_set_int_attr);
PSMOUSE_DEFINE_ATTR(resync_time, S_IWUSR | S_IRUGO,
			(void *) offsetof(struct psmouse, resync_time),
			psmouse_show_int_attr, psmouse_set_int_attr);

static struct attribute *psmouse_attributes[] = {
	&psmouse_attr_protocol.dattr.attr,
	&psmouse_attr_rate.dattr.attr,
	&psmouse_attr_resolution.dattr.attr,
	&psmouse_attr_resetafter.dattr.attr,
	&psmouse_attr_resync_time.dattr.attr,
	NULL
};

static const struct attribute_group psmouse_attribute_group = {
	.attrs	= psmouse_attributes,
};

/*
 * psmouse_mutex protects all operations changing state of mouse
 * (connecting, disconnecting, changing rate or resolution via
 * sysfs). We could use a per-device semaphore but since there
 * rarely more than one PS/2 mouse connected and since semaphore
 * is taken in "slow" paths it is not worth it.
 */
static DEFINE_MUTEX(psmouse_mutex);

static struct workqueue_struct *kpsmoused_wq;

void psmouse_report_standard_buttons(struct input_dev *dev, u8 buttons)
{
	input_report_key(dev, BTN_LEFT,   buttons & BIT(0));
	input_report_key(dev, BTN_MIDDLE, buttons & BIT(2));
	input_report_key(dev, BTN_RIGHT,  buttons & BIT(1));
}

void psmouse_report_standard_motion(struct input_dev *dev, u8 *packet)
{
	int x, y;

	x = packet[1] ? packet[1] - ((packet[0] << 4) & 0x100) : 0;
	y = packet[2] ? packet[2] - ((packet[0] << 3) & 0x100) : 0;

	input_report_rel(dev, REL_X, x);
	input_report_rel(dev, REL_Y, -y);
}

void psmouse_report_standard_packet(struct input_dev *dev, u8 *packet)
{
	psmouse_report_standard_buttons(dev, packet[0]);
	psmouse_report_standard_motion(dev, packet);
}

/*
 * psmouse_process_byte() analyzes the PS/2 data stream and reports
 * relevant events to the input module once full packet has arrived.
 */
psmouse_ret_t psmouse_process_byte(struct psmouse *psmouse)
{
	struct input_dev *dev = psmouse->dev;
	u8 *packet = psmouse->packet;
	int wheel;

	if (psmouse->pktcnt < psmouse->pktsize)
		return PSMOUSE_GOOD_DATA;

	/* Full packet accumulated, process it */

	switch (psmouse->protocol->type) {
	case PSMOUSE_IMPS:
		/* IntelliMouse has scroll wheel */
		input_report_rel(dev, REL_WHEEL, -(s8) packet[3]);
		break;

	case PSMOUSE_IMEX:
		/* Scroll wheel and buttons on IntelliMouse Explorer */
		switch (packet[3] & 0xC0) {
		case 0x80: /* vertical scroll on IntelliMouse Explorer 4.0 */
			input_report_rel(dev, REL_WHEEL,
					 -sign_extend32(packet[3], 5));
			break;
		case 0x40: /* horizontal scroll on IntelliMouse Explorer 4.0 */
			input_report_rel(dev, REL_HWHEEL,
					 -sign_extend32(packet[3], 5));
			break;
		case 0x00:
		case 0xC0:
			wheel = sign_extend32(packet[3], 3);

			/*
			 * Some A4Tech mice have two scroll wheels, with first
			 * one reporting +/-1 in the lower nibble, and second
			 * one reporting +/-2.
			 */
			if (psmouse_a4tech_2wheels && abs(wheel) > 1)
				input_report_rel(dev, REL_HWHEEL, wheel / 2);
			else
				input_report_rel(dev, REL_WHEEL, -wheel);

			input_report_key(dev, BTN_SIDE,  packet[3] & BIT(4));
			input_report_key(dev, BTN_EXTRA, packet[3] & BIT(5));
			break;
		}
		break;

	case PSMOUSE_GENPS:
		/* Report scroll buttons on NetMice */
		input_report_rel(dev, REL_WHEEL, -(s8) packet[3]);

		/* Extra buttons on Genius NewNet 3D */
		input_report_key(dev, BTN_SIDE,  packet[0] & BIT(6));
		input_report_key(dev, BTN_EXTRA, packet[0] & BIT(7));
		break;

	case PSMOUSE_THINKPS:
		/* Extra button on ThinkingMouse */
		input_report_key(dev, BTN_EXTRA, packet[0] & BIT(3));

		/*
		 * Without this bit of weirdness moving up gives wildly
		 * high Y changes.
		 */
		packet[1] |= (packet[0] & 0x40) << 1;
		break;

	case PSMOUSE_CORTRON:
		/*
		 * Cortron PS2 Trackball reports SIDE button in the
		 * 4th bit of the first byte.
		 */
		input_report_key(dev, BTN_SIDE, packet[0] & BIT(3));
		packet[0] |= BIT(3);
		break;

	default:
		break;
	}

	/* Generic PS/2 Mouse */
	packet[0] |= psmouse->extra_buttons;
	psmouse_report_standard_packet(dev, packet);

	input_sync(dev);

	return PSMOUSE_FULL_PACKET;
}

void psmouse_queue_work(struct psmouse *psmouse, struct delayed_work *work,
		unsigned long delay)
{
	queue_delayed_work(kpsmoused_wq, work, delay);
}

/*
 * __psmouse_set_state() sets new psmouse state and resets all flags.
 */
static inline void __psmouse_set_state(struct psmouse *psmouse, enum psmouse_state new_state)
{
	psmouse->state = new_state;
	psmouse->pktcnt = psmouse->out_of_sync_cnt = 0;
	psmouse->ps2dev.flags = 0;
	psmouse->last = jiffies;
}

/*
 * psmouse_set_state() sets new psmouse state and resets all flags and
 * counters while holding serio lock so fighting with interrupt handler
 * is not a concern.
 */
void psmouse_set_state(struct psmouse *psmouse, enum psmouse_state new_state)
{
	serio_pause_rx(psmouse->ps2dev.serio);
	__psmouse_set_state(psmouse, new_state);
	serio_continue_rx(psmouse->ps2dev.serio);
}

/*
 * psmouse_handle_byte() processes one byte of the input data stream
 * by calling corresponding protocol handler.
 */
static int psmouse_handle_byte(struct psmouse *psmouse)
{
	psmouse_ret_t rc = psmouse->protocol_handler(psmouse);

	switch (rc) {
	case PSMOUSE_BAD_DATA:
		if (psmouse->state == PSMOUSE_ACTIVATED) {
			psmouse_warn(psmouse,
				     "%s at %s lost sync at byte %d\n",
				     psmouse->name, psmouse->phys,
				     psmouse->pktcnt);
			if (++psmouse->out_of_sync_cnt == psmouse->resetafter) {
				__psmouse_set_state(psmouse, PSMOUSE_IGNORE);
				psmouse_notice(psmouse,
						"issuing reconnect request\n");
				serio_reconnect(psmouse->ps2dev.serio);
				return -EIO;
			}
		}
		psmouse->pktcnt = 0;
		break;

	case PSMOUSE_FULL_PACKET:
		psmouse->pktcnt = 0;
		if (psmouse->out_of_sync_cnt) {
			psmouse->out_of_sync_cnt = 0;
			psmouse_notice(psmouse,
					"%s at %s - driver resynced.\n",
					psmouse->name, psmouse->phys);
		}
		break;

	case PSMOUSE_GOOD_DATA:
		break;
	}
	return 0;
}

static void psmouse_handle_oob_data(struct psmouse *psmouse, u8 data)
{
	switch (psmouse->oob_data_type) {
	case PSMOUSE_OOB_NONE:
		psmouse->oob_data_type = data;
		break;

	case PSMOUSE_OOB_EXTRA_BTNS:
		psmouse_report_standard_buttons(psmouse->dev, data);
		input_sync(psmouse->dev);

		psmouse->extra_buttons = data;
		psmouse->oob_data_type = PSMOUSE_OOB_NONE;
		break;

	default:
		psmouse_warn(psmouse,
			     "unknown OOB_DATA type: 0x%02x\n",
			     psmouse->oob_data_type);
		psmouse->oob_data_type = PSMOUSE_OOB_NONE;
		break;
	}
}

/*
 * psmouse_interrupt() handles incoming characters, either passing them
 * for normal processing or gathering them as command response.
 */
static irqreturn_t psmouse_interrupt(struct serio *serio,
				     u8 data, unsigned int flags)
{
	struct psmouse *psmouse = serio_get_drvdata(serio);

	if (psmouse->state == PSMOUSE_IGNORE)
		goto out;

	if (unlikely((flags & SERIO_TIMEOUT) ||
		     ((flags & SERIO_PARITY) &&
		      !psmouse->protocol->ignore_parity))) {

		if (psmouse->state == PSMOUSE_ACTIVATED)
			psmouse_warn(psmouse,
				     "bad data from KBC -%s%s\n",
				     flags & SERIO_TIMEOUT ? " timeout" : "",
				     flags & SERIO_PARITY ? " bad parity" : "");
		ps2_cmd_aborted(&psmouse->ps2dev);
		goto out;
	}

	if (flags & SERIO_OOB_DATA) {
		psmouse_handle_oob_data(psmouse, data);
		goto out;
	}

	if (unlikely(psmouse->ps2dev.flags & PS2_FLAG_ACK))
		if  (ps2_handle_ack(&psmouse->ps2dev, data))
			goto out;

	if (unlikely(psmouse->ps2dev.flags & PS2_FLAG_CMD))
		if  (ps2_handle_response(&psmouse->ps2dev, data))
			goto out;

	pm_wakeup_event(&serio->dev, 0);

	if (psmouse->state <= PSMOUSE_RESYNCING)
		goto out;

	if (psmouse->state == PSMOUSE_ACTIVATED &&
	    psmouse->pktcnt && time_after(jiffies, psmouse->last + HZ/2)) {
		psmouse_info(psmouse, "%s at %s lost synchronization, throwing %d bytes away.\n",
			     psmouse->name, psmouse->phys, psmouse->pktcnt);
		psmouse->badbyte = psmouse->packet[0];
		__psmouse_set_state(psmouse, PSMOUSE_RESYNCING);
		psmouse_queue_work(psmouse, &psmouse->resync_work, 0);
		goto out;
	}

	psmouse->packet[psmouse->pktcnt++] = data;

	/* Check if this is a new device announcement (0xAA 0x00) */
	if (unlikely(psmouse->packet[0] == PSMOUSE_RET_BAT && psmouse->pktcnt <= 2)) {
		if (psmouse->pktcnt == 1) {
			psmouse->last = jiffies;
			goto out;
		}

		if (psmouse->packet[1] == PSMOUSE_RET_ID ||
		    (psmouse->protocol->type == PSMOUSE_HGPK &&
		     psmouse->packet[1] == PSMOUSE_RET_BAT)) {
			__psmouse_set_state(psmouse, PSMOUSE_IGNORE);
			serio_reconnect(serio);
			goto out;
		}

		/* Not a new device, try processing first byte normally */
		psmouse->pktcnt = 1;
		if (psmouse_handle_byte(psmouse))
			goto out;

		psmouse->packet[psmouse->pktcnt++] = data;
	}

	/*
	 * See if we need to force resync because mouse was idle for
	 * too long.
	 */
	if (psmouse->state == PSMOUSE_ACTIVATED &&
	    psmouse->pktcnt == 1 && psmouse->resync_time &&
	    time_after(jiffies, psmouse->last + psmouse->resync_time * HZ)) {
		psmouse->badbyte = psmouse->packet[0];
		__psmouse_set_state(psmouse, PSMOUSE_RESYNCING);
		psmouse_queue_work(psmouse, &psmouse->resync_work, 0);
		goto out;
	}

	psmouse->last = jiffies;
	psmouse_handle_byte(psmouse);

 out:
	return IRQ_HANDLED;
}

/*
 * psmouse_reset() resets the mouse into power-on state.
 */
int psmouse_reset(struct psmouse *psmouse)
{
	u8 param[2];
	int error;

	error = ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_RESET_BAT);
	if (error)
		return error;

	if (param[0] != PSMOUSE_RET_BAT && param[1] != PSMOUSE_RET_ID)
		return -EIO;

	return 0;
}

/*
 * Here we set the mouse resolution.
 */
void psmouse_set_resolution(struct psmouse *psmouse, unsigned int resolution)
{
	static const u8 params[] = { 0, 1, 2, 2, 3 };
	u8 p;

	if (resolution == 0 || resolution > 200)
		resolution = 200;

	p = params[resolution / 50];
	ps2_command(&psmouse->ps2dev, &p, PSMOUSE_CMD_SETRES);
	psmouse->resolution = 25 << p;
}

/*
 * Here we set the mouse report rate.
 */
static void psmouse_set_rate(struct psmouse *psmouse, unsigned int rate)
{
	static const u8 rates[] = { 200, 100, 80, 60, 40, 20, 10, 0 };
	u8 r;
	int i = 0;

	while (rates[i] > rate)
		i++;
	r = rates[i];
	ps2_command(&psmouse->ps2dev, &r, PSMOUSE_CMD_SETRATE);
	psmouse->rate = r;
}

/*
 * Here we set the mouse scaling.
 */
static void psmouse_set_scale(struct psmouse *psmouse, enum psmouse_scale scale)
{
	ps2_command(&psmouse->ps2dev, NULL,
		    scale == PSMOUSE_SCALE21 ? PSMOUSE_CMD_SETSCALE21 :
					       PSMOUSE_CMD_SETSCALE11);
}

/*
 * psmouse_poll() - default poll handler. Everyone except for ALPS uses it.
 */
static int psmouse_poll(struct psmouse *psmouse)
{
	return ps2_command(&psmouse->ps2dev, psmouse->packet,
			   PSMOUSE_CMD_POLL | (psmouse->pktsize << 8));
}

static bool psmouse_check_pnp_id(const char *id, const char * const ids[])
{
	int i;

	for (i = 0; ids[i]; i++)
		if (!strcasecmp(id, ids[i]))
			return true;

	return false;
}

/*
 * psmouse_matches_pnp_id - check if psmouse matches one of the passed in ids.
 */
bool psmouse_matches_pnp_id(struct psmouse *psmouse, const char * const ids[])
{
	struct serio *serio = psmouse->ps2dev.serio;
	char *p, *fw_id_copy, *save_ptr;
	bool found = false;

	if (strncmp(serio->firmware_id, "PNP: ", 5))
		return false;

	fw_id_copy = kstrndup(&serio->firmware_id[5],
			      sizeof(serio->firmware_id) - 5,
			      GFP_KERNEL);
	if (!fw_id_copy)
		return false;

	save_ptr = fw_id_copy;
	while ((p = strsep(&fw_id_copy, " ")) != NULL) {
		if (psmouse_check_pnp_id(p, ids)) {
			found = true;
			break;
		}
	}

	kfree(save_ptr);
	return found;
}

/*
 * Genius NetMouse magic init.
 */
static int genius_detect(struct psmouse *psmouse, bool set_properties)
{
	struct ps2dev *ps2dev = &psmouse->ps2dev;
	u8 param[4];

	param[0] = 3;
	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES);
	ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11);
	ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11);
	ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11);
	ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO);

	if (param[0] != 0x00 || param[1] != 0x33 || param[2] != 0x55)
		return -ENODEV;

	if (set_properties) {
		__set_bit(BTN_MIDDLE, psmouse->dev->keybit);
		__set_bit(BTN_EXTRA, psmouse->dev->keybit);
		__set_bit(BTN_SIDE, psmouse->dev->keybit);
		__set_bit(REL_WHEEL, psmouse->dev->relbit);

		psmouse->vendor = "Genius";
		psmouse->name = "Mouse";
		psmouse->pktsize = 4;
	}

	return 0;
}

/*
 * IntelliMouse magic init.
 */
static int intellimouse_detect(struct psmouse *psmouse, bool set_properties)
{
	struct ps2dev *ps2dev = &psmouse->ps2dev;
	u8 param[2];

	param[0] = 200;
	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
	param[0] = 100;
	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
	param[0] =  80;
	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
	ps2_command(ps2dev, param, PSMOUSE_CMD_GETID);

	if (param[0] != 3)
		return -ENODEV;

	if (set_properties) {
		__set_bit(BTN_MIDDLE, psmouse->dev->keybit);
		__set_bit(REL_WHEEL, psmouse->dev->relbit);

		if (!psmouse->vendor)
			psmouse->vendor = "Generic";
		if (!psmouse->name)
			psmouse->name = "Wheel Mouse";
		psmouse->pktsize = 4;
	}

	return 0;
}

/*
 * Try IntelliMouse/Explorer magic init.
 */
static int im_explorer_detect(struct psmouse *psmouse, bool set_properties)
{
	struct ps2dev *ps2dev = &psmouse->ps2dev;
	u8 param[2];

	intellimouse_detect(psmouse, 0);

	param[0] = 200;
	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
	param[0] = 200;
	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
	param[0] =  80;
	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
	ps2_command(ps2dev, param, PSMOUSE_CMD_GETID);

	if (param[0] != 4)
		return -ENODEV;

	/* Magic to enable horizontal scrolling on IntelliMouse 4.0 */
	param[0] = 200;
	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
	param[0] =  80;
	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
	param[0] =  40;
	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);

	if (set_properties) {
		__set_bit(BTN_MIDDLE, psmouse->dev->keybit);
		__set_bit(REL_WHEEL, psmouse->dev->relbit);
		__set_bit(REL_HWHEEL, psmouse->dev->relbit);
		__set_bit(BTN_SIDE, psmouse->dev->keybit);
		__set_bit(BTN_EXTRA, psmouse->dev->keybit);

		if (!psmouse->vendor)
			psmouse->vendor = "Generic";
		if (!psmouse->name)
			psmouse->name = "Explorer Mouse";
		psmouse->pktsize = 4;
	}

	return 0;
}

/*
 * Kensington ThinkingMouse / ExpertMouse magic init.
 */
static int thinking_detect(struct psmouse *psmouse, bool set_properties)
{
	struct ps2dev *ps2dev = &psmouse->ps2dev;
	u8 param[2];
	static const u8 seq[] = { 20, 60, 40, 20, 20, 60, 40, 20, 20 };
	int i;

	param[0] = 10;
	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
	param[0] = 0;
	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES);
	for (i = 0; i < ARRAY_SIZE(seq); i++) {
		param[0] = seq[i];
		ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
	}
	ps2_command(ps2dev, param, PSMOUSE_CMD_GETID);

	if (param[0] != 2)
		return -ENODEV;

	if (set_properties) {
		__set_bit(BTN_MIDDLE, psmouse->dev->keybit);
		__set_bit(BTN_EXTRA, psmouse->dev->keybit);

		psmouse->vendor = "Kensington";
		psmouse->name = "ThinkingMouse";
	}

	return 0;
}

/*
 * Bare PS/2 protocol "detection". Always succeeds.
 */
static int ps2bare_detect(struct psmouse *psmouse, bool set_properties)
{
	if (set_properties) {
		if (!psmouse->vendor)
			psmouse->vendor = "Generic";
		if (!psmouse->name)
			psmouse->name = "Mouse";

		/*
		 * We have no way of figuring true number of buttons so let's
		 * assume that the device has 3.
		 */
		input_set_capability(psmouse->dev, EV_KEY, BTN_MIDDLE);
	}

	return 0;
}

/*
 * Cortron PS/2 protocol detection. There's no special way to detect it, so it
 * must be forced by sysfs protocol writing.
 */
static int cortron_detect(struct psmouse *psmouse, bool set_properties)
{
	if (set_properties) {
		psmouse->vendor = "Cortron";
		psmouse->name = "PS/2 Trackball";

		__set_bit(BTN_MIDDLE, psmouse->dev->keybit);
		__set_bit(BTN_SIDE, psmouse->dev->keybit);
	}

	return 0;
}

static const struct psmouse_protocol psmouse_protocols[] = {
	{
		.type		= PSMOUSE_PS2,
		.name		= "PS/2",
		.alias		= "bare",
		.maxproto	= true,
		.ignore_parity	= true,
		.detect		= ps2bare_detect,
		.try_passthru	= true,
	},
#ifdef CONFIG_MOUSE_PS2_LOGIPS2PP
	{
		.type		= PSMOUSE_PS2PP,
		.name		= "PS2++",
		.alias		= "logitech",
		.detect		= ps2pp_detect,
	},
#endif
	{
		.type		= PSMOUSE_THINKPS,
		.name		= "ThinkPS/2",
		.alias		= "thinkps",
		.detect		= thinking_detect,
	},
#ifdef CONFIG_MOUSE_PS2_CYPRESS
	{
		.type		= PSMOUSE_CYPRESS,
		.name		= "CyPS/2",
		.alias		= "cypress",
		.detect		= cypress_detect,
		.init		= cypress_init,
	},
#endif
	{
		.type		= PSMOUSE_GENPS,
		.name		= "GenPS/2",
		.alias		= "genius",
		.detect		= genius_detect,
	},
	{
		.type		= PSMOUSE_IMPS,
		.name		= "ImPS/2",
		.alias		= "imps",
		.maxproto	= true,
		.ignore_parity	= true,
		.detect		= intellimouse_detect,
		.try_passthru	= true,
	},
	{
		.type		= PSMOUSE_IMEX,
		.name		= "ImExPS/2",
		.alias		= "exps",
		.maxproto	= true,
		.ignore_parity	= true,
		.detect		= im_explorer_detect,
		.try_passthru	= true,
	},
#ifdef CONFIG_MOUSE_PS2_SYNAPTICS
	{
		.type		= PSMOUSE_SYNAPTICS,
		.name		= "SynPS/2",
		.alias		= "synaptics",
		.detect		= synaptics_detect,
		.init		= synaptics_init_absolute,
	},
	{
		.type		= PSMOUSE_SYNAPTICS_RELATIVE,
		.name		= "SynRelPS/2",
		.alias		= "synaptics-relative",
		.detect		= synaptics_detect,
		.init		= synaptics_init_relative,
	},
#endif
#ifdef CONFIG_MOUSE_PS2_SYNAPTICS_SMBUS
	{
		.type		= PSMOUSE_SYNAPTICS_SMBUS,
		.name		= "SynSMBus",
		.alias		= "synaptics-smbus",
		.detect		= synaptics_detect,
		.init		= synaptics_init_smbus,
		.smbus_companion = true,
	},
#endif
#ifdef CONFIG_MOUSE_PS2_ALPS
	{
		.type		= PSMOUSE_ALPS,
		.name		= "AlpsPS/2",
		.alias		= "alps",
		.detect		= alps_detect,
		.init		= alps_init,
	},
#endif
#ifdef CONFIG_MOUSE_PS2_LIFEBOOK
	{
		.type		= PSMOUSE_LIFEBOOK,
		.name		= "LBPS/2",
		.alias		= "lifebook",
		.detect		= lifebook_detect,
		.init		= lifebook_init,
	},
#endif
#ifdef CONFIG_MOUSE_PS2_TRACKPOINT
	{
		.type		= PSMOUSE_TRACKPOINT,
		.name		= "TPPS/2",
		.alias		= "trackpoint",
		.detect		= trackpoint_detect,
		.try_passthru	= true,
	},
#endif
#ifdef CONFIG_MOUSE_PS2_TOUCHKIT
	{
		.type		= PSMOUSE_TOUCHKIT_PS2,
		.name		= "touchkitPS/2",
		.alias		= "touchkit",
		.detect		= touchkit_ps2_detect,
	},
#endif
#ifdef CONFIG_MOUSE_PS2_OLPC
	{
		.type		= PSMOUSE_HGPK,
		.name		= "OLPC HGPK",
		.alias		= "hgpk",
		.detect		= hgpk_detect,
	},
#endif
#ifdef CONFIG_MOUSE_PS2_ELANTECH
	{
		.type		= PSMOUSE_ELANTECH,
		.name		= "ETPS/2",
		.alias		= "elantech",
		.detect		= elantech_detect,
		.init		= elantech_init_ps2,
	},
#endif
#ifdef CONFIG_MOUSE_PS2_ELANTECH_SMBUS
	{
		.type		= PSMOUSE_ELANTECH_SMBUS,
		.name		= "ETSMBus",
		.alias		= "elantech-smbus",
		.detect		= elantech_detect,
		.init		= elantech_init_smbus,
		.smbus_companion = true,
	},
#endif
#ifdef CONFIG_MOUSE_PS2_SENTELIC
	{
		.type		= PSMOUSE_FSP,
		.name		= "FSPPS/2",
		.alias		= "fsp",
		.detect		= fsp_detect,
		.init		= fsp_init,
	},
#endif
	{
		.type		= PSMOUSE_CORTRON,
		.name		= "CortronPS/2",
		.alias		= "cortps",
		.detect		= cortron_detect,
	},
#ifdef CONFIG_MOUSE_PS2_FOCALTECH
	{
		.type		= PSMOUSE_FOCALTECH,
		.name		= "FocalTechPS/2",
		.alias		= "focaltech",
		.detect		= focaltech_detect,
		.init		= focaltech_init,
	},
#endif
#ifdef CONFIG_MOUSE_PS2_VMMOUSE
	{
		.type		= PSMOUSE_VMMOUSE,
		.name		= VMMOUSE_PSNAME,
		.alias		= "vmmouse",
		.detect		= vmmouse_detect,
		.init		= vmmouse_init,
	},
#endif
#ifdef CONFIG_MOUSE_PS2_BYD
	{
		.type		= PSMOUSE_BYD,
		.name		= "BYDPS/2",
		.alias		= "byd",
		.detect		= byd_detect,
		.init		= byd_init,
	},
#endif
	{
		.type		= PSMOUSE_AUTO,
		.name		= "auto",
		.alias		= "any",
		.maxproto	= true,
	},
};

static const struct psmouse_protocol *__psmouse_protocol_by_type(enum psmouse_type type)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(psmouse_protocols); i++)
		if (psmouse_protocols[i].type == type)
			return &psmouse_protocols[i];

	return NULL;
}

static const struct psmouse_protocol *psmouse_protocol_by_type(enum psmouse_type type)
{
	const struct psmouse_protocol *proto;

	proto = __psmouse_protocol_by_type(type);
	if (proto)
		return proto;

	WARN_ON(1);
	return &psmouse_protocols[0];
}

static const struct psmouse_protocol *psmouse_protocol_by_name(const char *name, size_t len)
{
	const struct psmouse_protocol *p;
	int i;

	for (i = 0; i < ARRAY_SIZE(psmouse_protocols); i++) {
		p = &psmouse_protocols[i];

		if ((strlen(p->name) == len && !strncmp(p->name, name, len)) ||
		    (strlen(p->alias) == len && !strncmp(p->alias, name, len)))
			return &psmouse_protocols[i];
	}

	return NULL;
}

/*
 * Apply default settings to the psmouse structure. Most of them will
 * be overridden by individual protocol initialization routines.
 */
static void psmouse_apply_defaults(struct psmouse *psmouse)
{
	struct input_dev *input_dev = psmouse->dev;

	bitmap_zero(input_dev->evbit, EV_CNT);
	bitmap_zero(input_dev->keybit, KEY_CNT);
	bitmap_zero(input_dev->relbit, REL_CNT);
	bitmap_zero(input_dev->absbit, ABS_CNT);
	bitmap_zero(input_dev->mscbit, MSC_CNT);

	input_set_capability(input_dev, EV_KEY, BTN_LEFT);
	input_set_capability(input_dev, EV_KEY, BTN_RIGHT);

	input_set_capability(input_dev, EV_REL, REL_X);
	input_set_capability(input_dev, EV_REL, REL_Y);

	__set_bit(INPUT_PROP_POINTER, input_dev->propbit);

	psmouse->protocol = &psmouse_protocols[0];

	psmouse->set_rate = psmouse_set_rate;
	psmouse->set_resolution = psmouse_set_resolution;
	psmouse->set_scale = psmouse_set_scale;
	psmouse->poll = psmouse_poll;
	psmouse->protocol_handler = psmouse_process_byte;
	psmouse->pktsize = 3;
	psmouse->reconnect = NULL;
	psmouse->fast_reconnect = NULL;
	psmouse->disconnect = NULL;
	psmouse->cleanup = NULL;
	psmouse->pt_activate = NULL;
	psmouse->pt_deactivate = NULL;
}

static bool psmouse_do_detect(int (*detect)(struct psmouse *, bool),
			      struct psmouse *psmouse, bool allow_passthrough,
			      bool set_properties)
{