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Commit 5d320294 authored by Daniel Ritz's avatar Daniel Ritz Committed by Greg Kroah-Hartman
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[PATCH] USB: input/touchkitusb: handle multiple packets 



Some versions of the controller seem to put multiple report packet into a
single urb. also it can happen that a packet is split across multiple urbs.
unpatched you get a jumpy cursor on some screens.
the patch does:
- handle multiple packets per urb
- handle packets split across multiple urb
- check packet type
- cleanups

Signed-off-by: default avatarDaniel Ritz <daniel.ritz@gmx.ch>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 8a4613f0

drivers/usb/input/touchkitusb.c

+126 −22
Original line number Diff line number Diff line 
/******************************************************************************

 * touchkitusb.c  --  Driver for eGalax TouchKit USB Touchscreens

 *

 * Copyright (C) 2004 by Daniel Ritz

 * Copyright (C) 2004-2005 by Daniel Ritz <daniel.ritz@gmx.ch>

 * Copyright (C) by Todd E. Johnson (mtouchusb.c)

 *

 * This program is free software; you can redistribute it and/or
@@ -41,15 +41,13 @@ 
#define TOUCHKIT_MAX_YC			0x07ff

#define TOUCHKIT_YC_FUZZ		0x0

#define TOUCHKIT_YC_FLAT		0x0

#define TOUCHKIT_REPORT_DATA_SIZE	8

#define TOUCHKIT_REPORT_DATA_SIZE	16



#define TOUCHKIT_DOWN			0x01

#define TOUCHKIT_POINT_TOUCH		0x81

#define TOUCHKIT_POINT_NOTOUCH		0x80



#define TOUCHKIT_GET_TOUCHED(dat)	((((dat)[0]) & TOUCHKIT_DOWN) ? 1 : 0)

#define TOUCHKIT_GET_X(dat)		(((dat)[3] << 7) | (dat)[4])

#define TOUCHKIT_GET_Y(dat)		(((dat)[1] << 7) | (dat)[2])

#define TOUCHKIT_PKT_TYPE_MASK		0xFE

#define TOUCHKIT_PKT_TYPE_REPT		0x80

#define TOUCHKIT_PKT_TYPE_DIAG		0x0A



#define DRIVER_VERSION			"v0.1"

#define DRIVER_AUTHOR			"Daniel Ritz <daniel.ritz@gmx.ch>"
@@ -62,6 +60,8 @@ MODULE_PARM_DESC(swap_xy, "If set X and Y axes are swapped."); 
struct touchkit_usb {

	unsigned char *data;

	dma_addr_t data_dma;

	char buffer[TOUCHKIT_REPORT_DATA_SIZE];

	int buf_len;

	struct urb *irq;

	struct usb_device *udev;

	struct input_dev *input;
@@ -77,11 +77,128 @@ static struct usb_device_id touchkit_devices[] = { 
	{}

};



/* helpers to read the data */

static inline int touchkit_get_touched(char *data)

{

	return (data[0] & TOUCHKIT_DOWN) ? 1 : 0;

}



static inline int touchkit_get_x(char *data)

{

	return ((data[3] & 0x0F) << 7) | (data[4] & 0x7F);

}



static inline int touchkit_get_y(char *data)

{

	return ((data[1] & 0x0F) << 7) | (data[2] & 0x7F);

}





/* processes one input packet. */

static void touchkit_process_pkt(struct touchkit_usb *touchkit,

                                 struct pt_regs *regs, char *pkt)

{

	int x, y;



	/* only process report packets */

	if ((pkt[0] & TOUCHKIT_PKT_TYPE_MASK) != TOUCHKIT_PKT_TYPE_REPT)

		return;



	if (swap_xy) {

		y = touchkit_get_x(pkt);

		x = touchkit_get_y(pkt);

	} else {

		x = touchkit_get_x(pkt);

		y = touchkit_get_y(pkt);

	}



	input_regs(touchkit->input, regs);

	input_report_key(touchkit->input, BTN_TOUCH, touchkit_get_touched(pkt));

	input_report_abs(touchkit->input, ABS_X, x);

	input_report_abs(touchkit->input, ABS_Y, y);

	input_sync(touchkit->input);

}





static int touchkit_get_pkt_len(char *buf)

{

	switch (buf[0] & TOUCHKIT_PKT_TYPE_MASK) {

	case TOUCHKIT_PKT_TYPE_REPT:

		return 5;



	case TOUCHKIT_PKT_TYPE_DIAG:

		return buf[1] + 2;

	}



	return 0;

}



static void touchkit_process(struct touchkit_usb *touchkit, int len,

                             struct pt_regs *regs)

{

	char *buffer;

	int pkt_len, buf_len, pos;



	/* if the buffer contains data, append */

	if (unlikely(touchkit->buf_len)) {

		int tmp;



		/* if only 1 byte in buffer, add another one to get length */

		if (touchkit->buf_len == 1)

			touchkit->buffer[1] = touchkit->data[0];



		pkt_len = touchkit_get_pkt_len(touchkit->buffer);



		/* unknown packet: drop everything */

		if (!pkt_len)

			return;



		/* append, process */

		tmp = pkt_len - touchkit->buf_len;

		memcpy(touchkit->buffer + touchkit->buf_len, touchkit->data, tmp);

		touchkit_process_pkt(touchkit, regs, touchkit->buffer);



		buffer = touchkit->data + tmp;

		buf_len = len - tmp;

	} else {

		buffer = touchkit->data;

		buf_len = len;

	}



	/* only one byte left in buffer */

	if (unlikely(buf_len == 1)) {

		touchkit->buffer[0] = buffer[0];

		touchkit->buf_len = 1;

		return;

	}



	/* loop over the buffer */

	pos = 0;

	while (pos < buf_len) {

		/* get packet len */

		pkt_len = touchkit_get_pkt_len(buffer + pos);



		/* unknown packet: drop everything */

		if (unlikely(!pkt_len))

			return;



		/* full packet: process */

		if (likely(pkt_len <= buf_len)) {

			touchkit_process_pkt(touchkit, regs, buffer + pos);

		} else {

			/* incomplete packet: save in buffer */

			memcpy(touchkit->buffer, buffer + pos, buf_len - pos);

			touchkit->buf_len = buf_len - pos;

		}

		pos += pkt_len;

	}

}





static void touchkit_irq(struct urb *urb, struct pt_regs *regs)

{

	struct touchkit_usb *touchkit = urb->context;

	int retval;

	int x, y;



	switch (urb->status) {

	case 0:
@@ -105,20 +222,7 @@ static void touchkit_irq(struct urb *urb, struct pt_regs *regs) 
		goto exit;

	}



	if (swap_xy) {

		y = TOUCHKIT_GET_X(touchkit->data);

		x = TOUCHKIT_GET_Y(touchkit->data);

	} else {

		x = TOUCHKIT_GET_X(touchkit->data);

		y = TOUCHKIT_GET_Y(touchkit->data);

	}



	input_regs(touchkit->input, regs);

	input_report_key(touchkit->input, BTN_TOUCH,

	                 TOUCHKIT_GET_TOUCHED(touchkit->data));

	input_report_abs(touchkit->input, ABS_X, x);

	input_report_abs(touchkit->input, ABS_Y, y);

	input_sync(touchkit->input);

	touchkit_process(touchkit, urb->actual_length, regs);



exit:

	retval = usb_submit_urb(urb, GFP_ATOMIC);