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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inexio.c (4477B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * iNexio serial touchscreen driver
      4 *
      5 * Copyright (c) 2008 Richard Lemon
      6 * Based on the mtouch driver (c) Vojtech Pavlik and Dan Streetman
      7 */
      8
      9
     10/*
     11 * 2008/06/19 Richard Lemon <richard@codelemon.com>
     12 *   Copied mtouch.c and edited for iNexio protocol
     13 */
     14
     15#include <linux/errno.h>
     16#include <linux/kernel.h>
     17#include <linux/module.h>
     18#include <linux/slab.h>
     19#include <linux/input.h>
     20#include <linux/serio.h>
     21
     22#define DRIVER_DESC	"iNexio serial touchscreen driver"
     23
     24MODULE_AUTHOR("Richard Lemon <richard@codelemon.com>");
     25MODULE_DESCRIPTION(DRIVER_DESC);
     26MODULE_LICENSE("GPL");
     27
     28/*
     29 * Definitions & global arrays.
     30 */
     31
     32#define INEXIO_FORMAT_TOUCH_BIT 0x01
     33#define INEXIO_FORMAT_LENGTH 5
     34#define INEXIO_RESPONSE_BEGIN_BYTE 0x80
     35
     36/* todo: check specs for max length of all responses */
     37#define INEXIO_MAX_LENGTH 16
     38
     39#define INEXIO_MIN_XC 0
     40#define INEXIO_MAX_XC 0x3fff
     41#define INEXIO_MIN_YC 0
     42#define INEXIO_MAX_YC 0x3fff
     43
     44#define INEXIO_GET_XC(data) (((data[1])<<7) | data[2])
     45#define INEXIO_GET_YC(data) (((data[3])<<7) | data[4])
     46#define INEXIO_GET_TOUCHED(data) (INEXIO_FORMAT_TOUCH_BIT & data[0])
     47
     48/*
     49 * Per-touchscreen data.
     50 */
     51
     52struct inexio {
     53	struct input_dev *dev;
     54	struct serio *serio;
     55	int idx;
     56	unsigned char data[INEXIO_MAX_LENGTH];
     57	char phys[32];
     58};
     59
     60static void inexio_process_data(struct inexio *pinexio)
     61{
     62	struct input_dev *dev = pinexio->dev;
     63
     64	if (INEXIO_FORMAT_LENGTH == ++pinexio->idx) {
     65		input_report_abs(dev, ABS_X, INEXIO_GET_XC(pinexio->data));
     66		input_report_abs(dev, ABS_Y, INEXIO_GET_YC(pinexio->data));
     67		input_report_key(dev, BTN_TOUCH, INEXIO_GET_TOUCHED(pinexio->data));
     68		input_sync(dev);
     69
     70		pinexio->idx = 0;
     71	}
     72}
     73
     74static irqreturn_t inexio_interrupt(struct serio *serio,
     75		unsigned char data, unsigned int flags)
     76{
     77	struct inexio *pinexio = serio_get_drvdata(serio);
     78
     79	pinexio->data[pinexio->idx] = data;
     80
     81	if (INEXIO_RESPONSE_BEGIN_BYTE&pinexio->data[0])
     82		inexio_process_data(pinexio);
     83	else
     84		printk(KERN_DEBUG "inexio.c: unknown/unsynchronized data from device, byte %x\n",pinexio->data[0]);
     85
     86	return IRQ_HANDLED;
     87}
     88
     89/*
     90 * inexio_disconnect() is the opposite of inexio_connect()
     91 */
     92
     93static void inexio_disconnect(struct serio *serio)
     94{
     95	struct inexio *pinexio = serio_get_drvdata(serio);
     96
     97	input_get_device(pinexio->dev);
     98	input_unregister_device(pinexio->dev);
     99	serio_close(serio);
    100	serio_set_drvdata(serio, NULL);
    101	input_put_device(pinexio->dev);
    102	kfree(pinexio);
    103}
    104
    105/*
    106 * inexio_connect() is the routine that is called when someone adds a
    107 * new serio device that supports iNexio protocol and registers it as
    108 * an input device. This is usually accomplished using inputattach.
    109 */
    110
    111static int inexio_connect(struct serio *serio, struct serio_driver *drv)
    112{
    113	struct inexio *pinexio;
    114	struct input_dev *input_dev;
    115	int err;
    116
    117	pinexio = kzalloc(sizeof(struct inexio), GFP_KERNEL);
    118	input_dev = input_allocate_device();
    119	if (!pinexio || !input_dev) {
    120		err = -ENOMEM;
    121		goto fail1;
    122	}
    123
    124	pinexio->serio = serio;
    125	pinexio->dev = input_dev;
    126	snprintf(pinexio->phys, sizeof(pinexio->phys), "%s/input0", serio->phys);
    127
    128	input_dev->name = "iNexio Serial TouchScreen";
    129	input_dev->phys = pinexio->phys;
    130	input_dev->id.bustype = BUS_RS232;
    131	input_dev->id.vendor = SERIO_INEXIO;
    132	input_dev->id.product = 0;
    133	input_dev->id.version = 0x0001;
    134	input_dev->dev.parent = &serio->dev;
    135	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
    136	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
    137	input_set_abs_params(pinexio->dev, ABS_X, INEXIO_MIN_XC, INEXIO_MAX_XC, 0, 0);
    138	input_set_abs_params(pinexio->dev, ABS_Y, INEXIO_MIN_YC, INEXIO_MAX_YC, 0, 0);
    139
    140	serio_set_drvdata(serio, pinexio);
    141
    142	err = serio_open(serio, drv);
    143	if (err)
    144		goto fail2;
    145
    146	err = input_register_device(pinexio->dev);
    147	if (err)
    148		goto fail3;
    149
    150	return 0;
    151
    152 fail3:	serio_close(serio);
    153 fail2:	serio_set_drvdata(serio, NULL);
    154 fail1:	input_free_device(input_dev);
    155	kfree(pinexio);
    156	return err;
    157}
    158
    159/*
    160 * The serio driver structure.
    161 */
    162
    163static const struct serio_device_id inexio_serio_ids[] = {
    164	{
    165		.type	= SERIO_RS232,
    166		.proto	= SERIO_INEXIO,
    167		.id	= SERIO_ANY,
    168		.extra	= SERIO_ANY,
    169	},
    170	{ 0 }
    171};
    172
    173MODULE_DEVICE_TABLE(serio, inexio_serio_ids);
    174
    175static struct serio_driver inexio_drv = {
    176	.driver		= {
    177		.name	= "inexio",
    178	},
    179	.description	= DRIVER_DESC,
    180	.id_table	= inexio_serio_ids,
    181	.interrupt	= inexio_interrupt,
    182	.connect	= inexio_connect,
    183	.disconnect	= inexio_disconnect,
    184};
    185
    186module_serio_driver(inexio_drv);