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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tsc40.c (3676B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * TSC-40 serial touchscreen driver. It should be compatible with
      4 * TSC-10 and 25.
      5 *
      6 * Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
      7 */
      8
      9#include <linux/kernel.h>
     10#include <linux/module.h>
     11#include <linux/slab.h>
     12#include <linux/input.h>
     13#include <linux/serio.h>
     14
     15#define PACKET_LENGTH  5
     16struct tsc_ser {
     17	struct input_dev *dev;
     18	struct serio *serio;
     19	u32 idx;
     20	unsigned char data[PACKET_LENGTH];
     21	char phys[32];
     22};
     23
     24static void tsc_process_data(struct tsc_ser *ptsc)
     25{
     26	struct input_dev *dev = ptsc->dev;
     27	u8 *data = ptsc->data;
     28	u32 x;
     29	u32 y;
     30
     31	x = ((data[1] & 0x03) << 8) | data[2];
     32	y = ((data[3] & 0x03) << 8) | data[4];
     33
     34	input_report_abs(dev, ABS_X, x);
     35	input_report_abs(dev, ABS_Y, y);
     36	input_report_key(dev, BTN_TOUCH, 1);
     37
     38	input_sync(dev);
     39}
     40
     41static irqreturn_t tsc_interrupt(struct serio *serio,
     42		unsigned char data, unsigned int flags)
     43{
     44	struct tsc_ser *ptsc = serio_get_drvdata(serio);
     45	struct input_dev *dev = ptsc->dev;
     46
     47	ptsc->data[ptsc->idx] = data;
     48	switch (ptsc->idx++) {
     49	case 0:
     50		if (unlikely((data & 0x3e) != 0x10)) {
     51			dev_dbg(&serio->dev,
     52				"unsynchronized packet start (0x%02x)\n", data);
     53			ptsc->idx = 0;
     54		} else if (!(data & 0x01)) {
     55			input_report_key(dev, BTN_TOUCH, 0);
     56			input_sync(dev);
     57			ptsc->idx = 0;
     58		}
     59		break;
     60
     61	case 1:
     62	case 3:
     63		if (unlikely(data & 0xfc)) {
     64			dev_dbg(&serio->dev,
     65				"unsynchronized data 0x%02x at offset %d\n",
     66				data, ptsc->idx - 1);
     67			ptsc->idx = 0;
     68		}
     69		break;
     70
     71	case 4:
     72		tsc_process_data(ptsc);
     73		ptsc->idx = 0;
     74		break;
     75	}
     76
     77	return IRQ_HANDLED;
     78}
     79
     80static int tsc_connect(struct serio *serio, struct serio_driver *drv)
     81{
     82	struct tsc_ser *ptsc;
     83	struct input_dev *input_dev;
     84	int error;
     85
     86	ptsc = kzalloc(sizeof(struct tsc_ser), GFP_KERNEL);
     87	input_dev = input_allocate_device();
     88	if (!ptsc || !input_dev) {
     89		error = -ENOMEM;
     90		goto fail1;
     91	}
     92
     93	ptsc->serio = serio;
     94	ptsc->dev = input_dev;
     95	snprintf(ptsc->phys, sizeof(ptsc->phys), "%s/input0", serio->phys);
     96
     97	input_dev->name = "TSC-10/25/40 Serial TouchScreen";
     98	input_dev->phys = ptsc->phys;
     99	input_dev->id.bustype = BUS_RS232;
    100	input_dev->id.vendor = SERIO_TSC40;
    101	input_dev->id.product = 40;
    102	input_dev->id.version = 0x0001;
    103	input_dev->dev.parent = &serio->dev;
    104
    105	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
    106	__set_bit(BTN_TOUCH, input_dev->keybit);
    107	input_set_abs_params(ptsc->dev, ABS_X, 0, 0x3ff, 0, 0);
    108	input_set_abs_params(ptsc->dev, ABS_Y, 0, 0x3ff, 0, 0);
    109
    110	serio_set_drvdata(serio, ptsc);
    111
    112	error = serio_open(serio, drv);
    113	if (error)
    114		goto fail2;
    115
    116	error = input_register_device(ptsc->dev);
    117	if (error)
    118		goto fail3;
    119
    120	return 0;
    121
    122fail3:
    123	serio_close(serio);
    124fail2:
    125	serio_set_drvdata(serio, NULL);
    126fail1:
    127	input_free_device(input_dev);
    128	kfree(ptsc);
    129	return error;
    130}
    131
    132static void tsc_disconnect(struct serio *serio)
    133{
    134	struct tsc_ser *ptsc = serio_get_drvdata(serio);
    135
    136	serio_close(serio);
    137
    138	input_unregister_device(ptsc->dev);
    139	kfree(ptsc);
    140
    141	serio_set_drvdata(serio, NULL);
    142}
    143
    144static const struct serio_device_id tsc_serio_ids[] = {
    145	{
    146		.type   = SERIO_RS232,
    147		.proto  = SERIO_TSC40,
    148		.id     = SERIO_ANY,
    149		.extra  = SERIO_ANY,
    150	},
    151	{ 0 }
    152};
    153MODULE_DEVICE_TABLE(serio, tsc_serio_ids);
    154
    155#define DRIVER_DESC    "TSC-10/25/40 serial touchscreen driver"
    156
    157static struct serio_driver tsc_drv = {
    158	.driver	= {
    159		.name   = "tsc40",
    160	},
    161	.description    = DRIVER_DESC,
    162	.id_table	= tsc_serio_ids,
    163	.interrupt      = tsc_interrupt,
    164	.connect	= tsc_connect,
    165	.disconnect     = tsc_disconnect,
    166};
    167
    168module_serio_driver(tsc_drv);
    169
    170MODULE_AUTHOR("Sebastian Andrzej Siewior <bigeasy@linutronix.de>");
    171MODULE_DESCRIPTION(DRIVER_DESC);
    172MODULE_LICENSE("GPL v2");