// SPDX-License-Identifier: GPL-2.0-only
/*
* Sahara TouchIT-213 serial touchscreen driver
*
* Copyright (c) 2007-2008 Claudio Nieder <private@claudio.ch>
*
* Based on Touchright driver (drivers/input/touchscreen/touchright.c)
* Copyright (c) 2006 Rick Koch <n1gp@hotmail.com>
* Copyright (c) 2004 Vojtech Pavlik
* and Dan Streetman <ddstreet@ieee.org>
*/
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/serio.h>
#define DRIVER_DESC "Sahara TouchIT-213 serial touchscreen driver"
MODULE_AUTHOR("Claudio Nieder <private@claudio.ch>");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
/*
* Definitions & global arrays.
*/
/*
* Data is received through COM1 at 9600bit/s,8bit,no parity in packets
* of 5 byte each.
*
* +--------+ +--------+ +--------+ +--------+ +--------+
* |1000000p| |0xxxxxxx| |0xxxxxxx| |0yyyyyyy| |0yyyyyyy|
* +--------+ +--------+ +--------+ +--------+ +--------+
* MSB LSB MSB LSB
*
* The value of p is 1 as long as the screen is touched and 0 when
* reporting the location where touching stopped, e.g. where the pen was
* lifted from the screen.
*
* When holding the screen in landscape mode as the BIOS text output is
* presented, x is the horizontal axis with values growing from left to
* right and y is the vertical axis with values growing from top to
* bottom.
*
* When holding the screen in portrait mode with the Sahara logo in its
* correct position, x ist the vertical axis with values growing from
* top to bottom and y is the horizontal axis with values growing from
* right to left.
*/
#define T213_FORMAT_TOUCH_BIT 0x01
#define T213_FORMAT_STATUS_BYTE 0x80
#define T213_FORMAT_STATUS_MASK ~T213_FORMAT_TOUCH_BIT
/*
* On my Sahara Touch-IT 213 I have observed x values from 0 to 0x7f0
* and y values from 0x1d to 0x7e9, so the actual measurement is
* probably done with an 11 bit precision.
*/
#define T213_MIN_XC 0
#define T213_MAX_XC 0x07ff
#define T213_MIN_YC 0
#define T213_MAX_YC 0x07ff
/*
* Per-touchscreen data.
*/
struct touchit213 {
struct input_dev *dev;
struct serio *serio;
int idx;
unsigned char csum;
unsigned char data[5];
char phys[32];
};
static irqreturn_t touchit213_interrupt(struct serio *serio,
unsigned char data, unsigned int flags)
{
struct touchit213 *touchit213 = serio_get_drvdata(serio);
struct input_dev *dev = touchit213->dev;
touchit213->data[touchit213->idx] = data;
switch (touchit213->idx++) {
case 0:
if ((touchit213->data[0] & T213_FORMAT_STATUS_MASK) !=
T213_FORMAT_STATUS_BYTE) {
pr_debug("unsynchronized data: 0x%02x\n", data);
touchit213->idx = 0;
}
break;
case 4:
touchit213->idx = 0;
input_report_abs(dev, ABS_X,
(touchit213->data[1] << 7) | touchit213->data[2]);
input_report_abs(dev, ABS_Y,
(touchit213->data[3] << 7) | touchit213->data[4]);
input_report_key(dev, BTN_TOUCH,
touchit213->data[0] & T213_FORMAT_TOUCH_BIT);
input_sync(dev);
break;
}
return IRQ_HANDLED;
}
/*
* touchit213_disconnect() is the opposite of touchit213_connect()
*/
static void touchit213_disconnect(struct serio *serio)
{
struct touchit213 *touchit213 = serio_get_drvdata(serio);
input_get_device(touchit213->dev);
input_unregister_device(touchit213->dev);
serio_close(serio);
serio_set_drvdata(serio, NULL);
input_put_device(touchit213->dev);
kfree(touchit213);
}
/*
* touchit213_connect() is the routine that is called when someone adds a
* new serio device that supports the Touchright protocol and registers it as
* an input device.
*/
static int touchit213_connect(struct serio *serio, struct serio_driver *drv)
{
struct touchit213 *touchit213;
struct input_dev *input_dev;
int err;
touchit213 = kzalloc(sizeof(struct touchit213), GFP_KERNEL);
input_dev = input_allocate_device();
if (!touchit213 || !input_dev) {
err = -ENOMEM;
goto fail1;
}
touchit213->serio = serio;
touchit213->dev = input_dev;
snprintf(touchit213->phys, sizeof(touchit213->phys),
"%s/input0", serio->phys);
input_dev->name = "Sahara Touch-iT213 Serial TouchScreen";
input_dev->phys = touchit213->phys;
input_dev->id.bustype = BUS_RS232;
input_dev->id.vendor = SERIO_TOUCHIT213;
input_dev->id.product = 0;
input_dev->id.version = 0x0100;
input_dev->dev.parent = &serio->dev;
input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
input_set_abs_params(touchit213->dev, ABS_X,
T213_MIN_XC, T213_MAX_XC, 0, 0);
input_set_abs_params(touchit213->dev, ABS_Y,
T213_MIN_YC, T213_MAX_YC, 0, 0);
serio_set_drvdata(serio, touchit213);
err = serio_open(serio, drv);
if (err)
goto fail2;
err = input_register_device(touchit213->dev);
if (err)
goto fail3;
return 0;
fail3: serio_close(serio);
fail2: serio_set_drvdata(serio, NULL);
fail1: input_free_device(input_dev);
kfree(touchit213);
return err;
}
/*
* The serio driver structure.
*/
static const struct serio_device_id touchit213_serio_ids[] = {
{
.type = SERIO_RS232,
.proto = SERIO_TOUCHIT213,
.id = SERIO_ANY,
.extra = SERIO_ANY,
},
{ 0 }
};
MODULE_DEVICE_TABLE(serio, touchit213_serio_ids);
static struct serio_driver touchit213_drv = {
.driver = {
.name = "touchit213",
},
.description = DRIVER_DESC,
.id_table = touchit213_serio_ids,
.interrupt = touchit213_interrupt,
.connect = touchit213_connect,
.disconnect = touchit213_disconnect,
};
module_serio_driver(touchit213_drv);
