cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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touchwin.c (3999B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Touchwindow serial touchscreen driver
      4 *
      5 * Copyright (c) 2006 Rick Koch <n1gp@hotmail.com>
      6 *
      7 * Based on MicroTouch driver (drivers/input/touchscreen/mtouch.c)
      8 * Copyright (c) 2004 Vojtech Pavlik
      9 * and Dan Streetman <ddstreet@ieee.org>
     10 */
     11
     12
     13/*
     14 * 2005/02/19 Rick Koch:
     15 *   The Touchwindow I used is made by Edmark Corp. and
     16 *   constantly outputs a stream of 0's unless it is touched.
     17 *   It then outputs 3 bytes: X, Y, and a copy of Y.
     18 */
     19
     20#include <linux/errno.h>
     21#include <linux/kernel.h>
     22#include <linux/module.h>
     23#include <linux/slab.h>
     24#include <linux/input.h>
     25#include <linux/serio.h>
     26
     27#define DRIVER_DESC	"Touchwindow serial touchscreen driver"
     28
     29MODULE_AUTHOR("Rick Koch <n1gp@hotmail.com>");
     30MODULE_DESCRIPTION(DRIVER_DESC);
     31MODULE_LICENSE("GPL");
     32
     33/*
     34 * Definitions & global arrays.
     35 */
     36
     37#define TW_LENGTH 3
     38
     39#define TW_MIN_XC 0
     40#define TW_MAX_XC 0xff
     41#define TW_MIN_YC 0
     42#define TW_MAX_YC 0xff
     43
     44/*
     45 * Per-touchscreen data.
     46 */
     47
     48struct tw {
     49	struct input_dev *dev;
     50	struct serio *serio;
     51	int idx;
     52	int touched;
     53	unsigned char data[TW_LENGTH];
     54	char phys[32];
     55};
     56
     57static irqreturn_t tw_interrupt(struct serio *serio,
     58		unsigned char data, unsigned int flags)
     59{
     60	struct tw *tw = serio_get_drvdata(serio);
     61	struct input_dev *dev = tw->dev;
     62
     63	if (data) {		/* touch */
     64		tw->touched = 1;
     65		tw->data[tw->idx++] = data;
     66		/* verify length and that the two Y's are the same */
     67		if (tw->idx == TW_LENGTH && tw->data[1] == tw->data[2]) {
     68			input_report_abs(dev, ABS_X, tw->data[0]);
     69			input_report_abs(dev, ABS_Y, tw->data[1]);
     70			input_report_key(dev, BTN_TOUCH, 1);
     71			input_sync(dev);
     72			tw->idx = 0;
     73		}
     74	} else if (tw->touched) {	/* untouch */
     75		input_report_key(dev, BTN_TOUCH, 0);
     76		input_sync(dev);
     77		tw->idx = 0;
     78		tw->touched = 0;
     79	}
     80
     81	return IRQ_HANDLED;
     82}
     83
     84/*
     85 * tw_disconnect() is the opposite of tw_connect()
     86 */
     87
     88static void tw_disconnect(struct serio *serio)
     89{
     90	struct tw *tw = serio_get_drvdata(serio);
     91
     92	input_get_device(tw->dev);
     93	input_unregister_device(tw->dev);
     94	serio_close(serio);
     95	serio_set_drvdata(serio, NULL);
     96	input_put_device(tw->dev);
     97	kfree(tw);
     98}
     99
    100/*
    101 * tw_connect() is the routine that is called when someone adds a
    102 * new serio device that supports the Touchwin protocol and registers it as
    103 * an input device.
    104 */
    105
    106static int tw_connect(struct serio *serio, struct serio_driver *drv)
    107{
    108	struct tw *tw;
    109	struct input_dev *input_dev;
    110	int err;
    111
    112	tw = kzalloc(sizeof(struct tw), GFP_KERNEL);
    113	input_dev = input_allocate_device();
    114	if (!tw || !input_dev) {
    115		err = -ENOMEM;
    116		goto fail1;
    117	}
    118
    119	tw->serio = serio;
    120	tw->dev = input_dev;
    121	snprintf(tw->phys, sizeof(tw->phys), "%s/input0", serio->phys);
    122
    123	input_dev->name = "Touchwindow Serial TouchScreen";
    124	input_dev->phys = tw->phys;
    125	input_dev->id.bustype = BUS_RS232;
    126	input_dev->id.vendor = SERIO_TOUCHWIN;
    127	input_dev->id.product = 0;
    128	input_dev->id.version = 0x0100;
    129	input_dev->dev.parent = &serio->dev;
    130	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
    131	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
    132	input_set_abs_params(tw->dev, ABS_X, TW_MIN_XC, TW_MAX_XC, 0, 0);
    133	input_set_abs_params(tw->dev, ABS_Y, TW_MIN_YC, TW_MAX_YC, 0, 0);
    134
    135	serio_set_drvdata(serio, tw);
    136
    137	err = serio_open(serio, drv);
    138	if (err)
    139		goto fail2;
    140
    141	err = input_register_device(tw->dev);
    142	if (err)
    143		goto fail3;
    144
    145	return 0;
    146
    147 fail3:	serio_close(serio);
    148 fail2:	serio_set_drvdata(serio, NULL);
    149 fail1:	input_free_device(input_dev);
    150	kfree(tw);
    151	return err;
    152}
    153
    154/*
    155 * The serio driver structure.
    156 */
    157
    158static const struct serio_device_id tw_serio_ids[] = {
    159	{
    160		.type	= SERIO_RS232,
    161		.proto	= SERIO_TOUCHWIN,
    162		.id	= SERIO_ANY,
    163		.extra	= SERIO_ANY,
    164	},
    165	{ 0 }
    166};
    167
    168MODULE_DEVICE_TABLE(serio, tw_serio_ids);
    169
    170static struct serio_driver tw_drv = {
    171	.driver		= {
    172		.name	= "touchwin",
    173	},
    174	.description	= DRIVER_DESC,
    175	.id_table	= tw_serio_ids,
    176	.interrupt	= tw_interrupt,
    177	.connect	= tw_connect,
    178	.disconnect	= tw_disconnect,
    179};
    180
    181module_serio_driver(tw_drv);