Revision 65deeed7b34bc5b8d3cbff495e8fa2ae7b563480 authored by Greg Rose on 24 March 2010, 09:35:42 UTC, committed by David S. Miller on 26 March 2010, 18:56:00 UTC
In the Tx mapping function if a DMA error occurred then the unwind of
previously mapped sections would improperly check an unsigned int if
it was less than zero.  Changed the index variable to signed to avoid
the error.

Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent 48c11a5
Raw File
hid-3m-pct.c
/*
 *  HID driver for 3M PCT multitouch panels
 *
 *  Copyright (c) 2009 Stephane Chatty <chatty@enac.fr>
 *
 */

/*
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 */

#include <linux/device.h>
#include <linux/hid.h>
#include <linux/module.h>
#include <linux/usb.h>

MODULE_AUTHOR("Stephane Chatty <chatty@enac.fr>");
MODULE_DESCRIPTION("3M PCT multitouch panels");
MODULE_LICENSE("GPL");

#include "hid-ids.h"

struct mmm_finger {
	__s32 x, y;
	__u8 rank;
	bool touch, valid;
};

struct mmm_data {
	struct mmm_finger f[10];
	__u8 curid, num;
	bool touch, valid;
};

static int mmm_input_mapping(struct hid_device *hdev, struct hid_input *hi,
		struct hid_field *field, struct hid_usage *usage,
		unsigned long **bit, int *max)
{
	switch (usage->hid & HID_USAGE_PAGE) {

	case HID_UP_BUTTON:
		return -1;

	case HID_UP_GENDESK:
		switch (usage->hid) {
		case HID_GD_X:
			hid_map_usage(hi, usage, bit, max,
					EV_ABS, ABS_MT_POSITION_X);
			/* touchscreen emulation */
			input_set_abs_params(hi->input, ABS_X,
						field->logical_minimum,
						field->logical_maximum, 0, 0);
			return 1;
		case HID_GD_Y:
			hid_map_usage(hi, usage, bit, max,
					EV_ABS, ABS_MT_POSITION_Y);
			/* touchscreen emulation */
			input_set_abs_params(hi->input, ABS_Y,
						field->logical_minimum,
						field->logical_maximum, 0, 0);
			return 1;
		}
		return 0;

	case HID_UP_DIGITIZER:
		switch (usage->hid) {
		/* we do not want to map these: no input-oriented meaning */
		case 0x14:
		case 0x23:
		case HID_DG_INPUTMODE:
		case HID_DG_DEVICEINDEX:
		case HID_DG_CONTACTCOUNT:
		case HID_DG_CONTACTMAX:
		case HID_DG_INRANGE:
		case HID_DG_CONFIDENCE:
			return -1;
		case HID_DG_TIPSWITCH:
			/* touchscreen emulation */
			hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
			return 1;
		case HID_DG_CONTACTID:
			hid_map_usage(hi, usage, bit, max,
					EV_ABS, ABS_MT_TRACKING_ID);
			return 1;
		}
		/* let hid-input decide for the others */
		return 0;

	case 0xff000000:
		/* we do not want to map these: no input-oriented meaning */
		return -1;
	}

	return 0;
}

static int mmm_input_mapped(struct hid_device *hdev, struct hid_input *hi,
		struct hid_field *field, struct hid_usage *usage,
		unsigned long **bit, int *max)
{
	if (usage->type == EV_KEY || usage->type == EV_ABS)
		clear_bit(usage->code, *bit);

	return 0;
}

/*
 * this function is called when a whole packet has been received and processed,
 * so that it can decide what to send to the input layer.
 */
static void mmm_filter_event(struct mmm_data *md, struct input_dev *input)
{
	struct mmm_finger *oldest = 0;
	bool pressed = false, released = false;
	int i;

	/*
	 * we need to iterate on all fingers to decide if we have a press
	 * or a release event in our touchscreen emulation.
	 */
	for (i = 0; i < 10; ++i) {
		struct mmm_finger *f = &md->f[i];
		if (!f->valid) {
			/* this finger is just placeholder data, ignore */
		} else if (f->touch) {
			/* this finger is on the screen */
			input_event(input, EV_ABS, ABS_MT_TRACKING_ID, i);
			input_event(input, EV_ABS, ABS_MT_POSITION_X, f->x);
			input_event(input, EV_ABS, ABS_MT_POSITION_Y, f->y);
			input_mt_sync(input);
			/*
			 * touchscreen emulation: maintain the age rank
			 * of this finger, decide if we have a press
			 */
			if (f->rank == 0) {
				f->rank = ++(md->num);
				if (f->rank == 1)
					pressed = true;
			}
			if (f->rank == 1)
				oldest = f;
		} else {
			/* this finger took off the screen */
			/* touchscreen emulation: maintain age rank of others */
			int j;

			for (j = 0; j < 10; ++j) {
				struct mmm_finger *g = &md->f[j];
				if (g->rank > f->rank) {
					g->rank--;
					if (g->rank == 1)
						oldest = g;
				}
			}
			f->rank = 0;
			--(md->num);
			if (md->num == 0)
				released = true;
		}
		f->valid = 0;
	}

	/* touchscreen emulation */
	if (oldest) {
		if (pressed)
			input_event(input, EV_KEY, BTN_TOUCH, 1);
		input_event(input, EV_ABS, ABS_X, oldest->x);
		input_event(input, EV_ABS, ABS_Y, oldest->y);
	} else if (released) {
		input_event(input, EV_KEY, BTN_TOUCH, 0);
	}
}

/*
 * this function is called upon all reports
 * so that we can accumulate contact point information,
 * and call input_mt_sync after each point.
 */
static int mmm_event(struct hid_device *hid, struct hid_field *field,
				struct hid_usage *usage, __s32 value)
{
	struct mmm_data *md = hid_get_drvdata(hid);
	/*
	 * strangely, this function can be called before
	 * field->hidinput is initialized!
	 */
	if (hid->claimed & HID_CLAIMED_INPUT) {
		struct input_dev *input = field->hidinput->input;
		switch (usage->hid) {
		case HID_DG_TIPSWITCH:
			md->touch = value;
			break;
		case HID_DG_CONFIDENCE:
			md->valid = value;
			break;
		case HID_DG_CONTACTID:
			if (md->valid) {
				md->curid = value;
				md->f[value].touch = md->touch;
				md->f[value].valid = 1;
			}
			break;
		case HID_GD_X:
			if (md->valid)
				md->f[md->curid].x = value;
			break;
		case HID_GD_Y:
			if (md->valid)
				md->f[md->curid].y = value;
			break;
		case HID_DG_CONTACTCOUNT:
			mmm_filter_event(md, input);
			break;
		}
	}

	/* we have handled the hidinput part, now remains hiddev */
	if (hid->claimed & HID_CLAIMED_HIDDEV && hid->hiddev_hid_event)
		hid->hiddev_hid_event(hid, field, usage, value);

	return 1;
}

static int mmm_probe(struct hid_device *hdev, const struct hid_device_id *id)
{
	int ret;
	struct mmm_data *md;

	md = kzalloc(sizeof(struct mmm_data), GFP_KERNEL);
	if (!md) {
		dev_err(&hdev->dev, "cannot allocate 3M data\n");
		return -ENOMEM;
	}
	hid_set_drvdata(hdev, md);

	ret = hid_parse(hdev);
	if (!ret)
		ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);

	if (ret)
		kfree(md);
	return ret;
}

static void mmm_remove(struct hid_device *hdev)
{
	hid_hw_stop(hdev);
	kfree(hid_get_drvdata(hdev));
	hid_set_drvdata(hdev, NULL);
}

static const struct hid_device_id mmm_devices[] = {
	{ HID_USB_DEVICE(USB_VENDOR_ID_3M, USB_DEVICE_ID_3M1968) },
	{ }
};
MODULE_DEVICE_TABLE(hid, mmm_devices);

static const struct hid_usage_id mmm_grabbed_usages[] = {
	{ HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
	{ HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
};

static struct hid_driver mmm_driver = {
	.name = "3m-pct",
	.id_table = mmm_devices,
	.probe = mmm_probe,
	.remove = mmm_remove,
	.input_mapping = mmm_input_mapping,
	.input_mapped = mmm_input_mapped,
	.usage_table = mmm_grabbed_usages,
	.event = mmm_event,
};

static int __init mmm_init(void)
{
	return hid_register_driver(&mmm_driver);
}

static void __exit mmm_exit(void)
{
	hid_unregister_driver(&mmm_driver);
}

module_init(mmm_init);
module_exit(mmm_exit);
MODULE_LICENSE("GPL");

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