/*
* Wacom W8001 penabled serial touchscreen driver
*
* Copyright (c) 2008 Jaya Kumar
* Copyright (c) 2010 Red Hat, Inc.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of this archive for
* more details.
*
* Layout based on Elo serial touchscreen driver by Vojtech Pavlik
*/
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input/mt.h>
#include <linux/serio.h>
#include <linux/init.h>
#include <linux/ctype.h>
#include <linux/delay.h>
#define DRIVER_DESC "Wacom W8001 serial touchscreen driver"
MODULE_AUTHOR("Jaya Kumar <jayakumar.lkml@gmail.com>");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
#define W8001_MAX_LENGTH 11
#define W8001_LEAD_MASK 0x80
#define W8001_LEAD_BYTE 0x80
#define W8001_TAB_MASK 0x40
#define W8001_TAB_BYTE 0x40
/* set in first byte of touch data packets */
#define W8001_TOUCH_MASK (0x10 | W8001_LEAD_MASK)
#define W8001_TOUCH_BYTE (0x10 | W8001_LEAD_BYTE)
#define W8001_QUERY_PACKET 0x20
#define W8001_CMD_STOP '0'
#define W8001_CMD_START '1'
#define W8001_CMD_QUERY '*'
#define W8001_CMD_TOUCHQUERY '%'
/* length of data packets in bytes, depends on device. */
#define W8001_PKTLEN_TOUCH93 5
#define W8001_PKTLEN_TOUCH9A 7
#define W8001_PKTLEN_TPCPEN 9
#define W8001_PKTLEN_TPCCTL 11 /* control packet */
#define W8001_PKTLEN_TOUCH2FG 13
struct w8001_coord {
u8 rdy;
u8 tsw;
u8 f1;
u8 f2;
u16 x;
u16 y;
u16 pen_pressure;
u8 tilt_x;
u8 tilt_y;
};
/* touch query reply packet */
struct w8001_touch_query {
u8 panel_res;
u8 capacity_res;
u8 sensor_id;
u16 x;
u16 y;
};
/*
* Per-touchscreen data.
*/
struct w8001 {
struct input_dev *dev;
struct serio *serio;
struct completion cmd_done;
int id;
int idx;
unsigned char response_type;
unsigned char response[W8001_MAX_LENGTH];
unsigned char data[W8001_MAX_LENGTH];
char phys[32];
int type;
unsigned int pktlen;
};
static void parse_data(u8 *data, struct w8001_coord *coord)
{
memset(coord, 0, sizeof(*coord));
coord->rdy = data[0] & 0x20;
coord->tsw = data[0] & 0x01;
coord->f1 = data[0] & 0x02;
coord->f2 = data[0] & 0x04;
coord->x = (data[1] & 0x7F) << 9;
coord->x |= (data[2] & 0x7F) << 2;
coord->x |= (data[6] & 0x60) >> 5;
coord->y = (data[3] & 0x7F) << 9;
coord->y |= (data[4] & 0x7F) << 2;
coord->y |= (data[6] & 0x18) >> 3;
coord->pen_pressure = data[5] & 0x7F;
coord->pen_pressure |= (data[6] & 0x07) << 7 ;
coord->tilt_x = data[7] & 0x7F;
coord->tilt_y = data[8] & 0x7F;
}
static void parse_touch(struct w8001 *w8001)
{
struct input_dev *dev = w8001->dev;
unsigned char *data = w8001->data;
int i;
for (i = 0; i < 2; i++) {
bool touch = data[0] & (1 << i);
input_mt_slot(dev, i);
input_mt_report_slot_state(dev, MT_TOOL_FINGER, touch);
if (touch) {
int x = (data[6 * i + 1] << 7) | (data[6 * i + 2]);
int y = (data[6 * i + 3] << 7) | (data[6 * i + 4]);
/* data[5,6] and [11,12] is finger capacity */
input_report_abs(dev, ABS_MT_POSITION_X, x);
input_report_abs(dev, ABS_MT_POSITION_Y, y);
}
}
input_sync(dev);
}
static void parse_touchquery(u8 *data, struct w8001_touch_query *query)
{
memset(query, 0, sizeof(*query));
query->panel_res = data[1];
query->sensor_id = data[2] & 0x7;
query->capacity_res = data[7];
query->x = data[3] << 9;
query->x |= data[4] << 2;
query->x |= (data[2] >> 5) & 0x3;
query->y = data[5] << 9;
query->y |= data[6] << 2;
query->y |= (data[2] >> 3) & 0x3;
}
static void report_pen_events(struct w8001 *w8001, struct w8001_coord *coord)
{
struct input_dev *dev = w8001->dev;
/*
* We have 1 bit for proximity (rdy) and 3 bits for tip, side,
* side2/eraser. If rdy && f2 are set, this can be either pen + side2,
* or eraser. assume
* - if dev is already in proximity and f2 is toggled → pen + side2
* - if dev comes into proximity with f2 set → eraser
* If f2 disappears after assuming eraser, fake proximity out for
* eraser and in for pen.
*/
if (!w8001->type) {
w8001->type = coord->f2 ? BTN_TOOL_RUBBER : BTN_TOOL_PEN;
} else if (w8001->type == BTN_TOOL_RUBBER) {
if (!coord->f2) {
input_report_abs(dev, ABS_PRESSURE, 0);
input_report_key(dev, BTN_TOUCH, 0);
input_report_key(dev, BTN_STYLUS, 0);
input_report_key(dev, BTN_STYLUS2, 0);
input_report_key(dev, BTN_TOOL_RUBBER, 0);
input_sync(dev);
w8001->type = BTN_TOOL_PEN;
}
} else {
input_report_key(dev, BTN_STYLUS2, coord->f2);
}
input_report_abs(dev, ABS_X, coord->x);
input_report_abs(dev, ABS_Y, coord->y);
input_report_abs(dev, ABS_PRESSURE, coord->pen_pressure);
input_report_key(dev, BTN_TOUCH, coord->tsw);
input_report_key(dev, BTN_STYLUS, coord->f1);
input_report_key(dev, w8001->type, coord->rdy);
input_sync(dev);
if (!coord->rdy)
w8001->type = 0;
}
static irqreturn_t w8001_interrupt(struct serio *serio,
unsigned char data, unsigned int flags)
{
struct w8001 *w8001 = serio_get_drvdata(serio);
struct w8001_coord coord;
unsigned char tmp;
w8001->data[w8001->idx] = data;
switch (w8001->idx++) {
case 0:
if ((data & W8001_LEAD_MASK) != W8001_LEAD_BYTE) {
pr_debug("w8001: unsynchronized data: 0x%02x\n", data);
w8001->idx = 0;
}
break;
case W8001_PKTLEN_TOUCH93 - 1:
case W8001_PKTLEN_TOUCH9A - 1:
/* ignore one-finger touch packet. */
if (w8001->pktlen == w8001->idx)
w8001->idx = 0;
break;
/* Pen coordinates packet */
case W8001_PKTLEN_TPCPEN - 1:
tmp = w8001->data[0] & W8001_TAB_MASK;
if (unlikely(tmp == W8001_TAB_BYTE))
break;
tmp = (w8001->data[0] & W8001_TOUCH_BYTE);
if (tmp == W8001_TOUCH_BYTE)
break;
w8001->idx = 0;
parse_data(w8001->data, &coord);
report_pen_events(w8001, &coord);
break;
/* control packet */
case W8001_PKTLEN_TPCCTL - 1:
tmp = (w8001->data[0] & W8001_TOUCH_MASK);
if (tmp == W8001_TOUCH_BYTE)
break;
w8001->idx = 0;
memcpy(w8001->response, w8001->data, W8001_MAX_LENGTH);
w8001->response_type = W8001_QUERY_PACKET;
complete(&w8001->cmd_done);
break;
/* 2 finger touch packet */
case W8001_PKTLEN_TOUCH2FG - 1:
w8001->idx = 0;
parse_touch(w8001);
break;
}
return IRQ_HANDLED;
}
static int w8001_command(struct w8001 *w8001, unsigned char command,
bool wait_response)
{
int rc;
w8001->response_type = 0;
init_completion(&w8001->cmd_done);
rc = serio_write(w8001->serio, command);
if (rc == 0 && wait_response) {
wait_for_completion_timeout(&w8001->cmd_done, HZ);
if (w8001->response_type != W8001_QUERY_PACKET)
rc = -EIO;
}
return rc;
}
static int w8001_setup(struct w8001 *w8001)
{
struct input_dev *dev = w8001->dev;
struct w8001_coord coord;
int error;
error = w8001_command(w8001, W8001_CMD_STOP, false);
if (error)
return error;
msleep(250); /* wait 250ms before querying the device */
/* penabled? */
error = w8001_command(w8001, W8001_CMD_QUERY, true);
if (!error) {
__set_bit(BTN_TOOL_PEN, dev->keybit);
__set_bit(BTN_TOOL_RUBBER, dev->keybit);
__set_bit(BTN_STYLUS, dev->keybit);
__set_bit(BTN_STYLUS2, dev->keybit);
parse_data(w8001->response, &coord);
input_set_abs_params(dev, ABS_X, 0, coord.x, 0, 0);
input_set_abs_params(dev, ABS_Y, 0, coord.y, 0, 0);
input_set_abs_params(dev, ABS_PRESSURE, 0, coord.pen_pressure, 0, 0);
if (coord.tilt_x && coord.tilt_y) {
input_set_abs_params(dev, ABS_TILT_X, 0, coord.tilt_x, 0, 0);
input_set_abs_params(dev, ABS_TILT_Y, 0, coord.tilt_y, 0, 0);
}
}
/* Touch enabled? */
error = w8001_command(w8001, W8001_CMD_TOUCHQUERY, true);
/*
* Some non-touch devices may reply to the touch query. But their
* second byte is empty, which indicates touch is not supported.
*/
if (!error && w8001->response[1]) {
struct w8001_touch_query touch;
parse_touchquery(w8001->response, &touch);
input_set_abs_params(dev, ABS_X, 0, touch.x, 0, 0);
input_set_abs_params(dev, ABS_Y, 0, touch.y, 0, 0);
__set_bit(BTN_TOOL_FINGER, dev->keybit);
switch (touch.sensor_id) {
case 0:
case 2:
w8001->pktlen = W8001_PKTLEN_TOUCH93;
break;
case 1:
case 3:
case 4:
w8001->pktlen = W8001_PKTLEN_TOUCH9A;
break;
case 5:
w8001->pktlen = W8001_PKTLEN_TOUCH2FG;
input_mt_init_slots(dev, 2);
input_set_abs_params(dev, ABS_MT_POSITION_X,
0, touch.x, 0, 0);
input_set_abs_params(dev, ABS_MT_POSITION_Y,
0, touch.y, 0, 0);
input_set_abs_params(dev, ABS_MT_TOOL_TYPE,
0, MT_TOOL_MAX, 0, 0);
break;
}
}
return w8001_command(w8001, W8001_CMD_START, false);
}
/*
* w8001_disconnect() is the opposite of w8001_connect()
*/
static void w8001_disconnect(struct serio *serio)
{
struct w8001 *w8001 = serio_get_drvdata(serio);
input_get_device(w8001->dev);
input_unregister_device(w8001->dev);
serio_close(serio);
serio_set_drvdata(serio, NULL);
input_put_device(w8001->dev);
kfree(w8001);
}
/*
* w8001_connect() is the routine that is called when someone adds a
* new serio device that supports the w8001 protocol and registers it as
* an input device.
*/
static int w8001_connect(struct serio *serio, struct serio_driver *drv)
{
struct w8001 *w8001;
struct input_dev *input_dev;
int err;
w8001 = kzalloc(sizeof(struct w8001), GFP_KERNEL);
input_dev = input_allocate_device();
if (!w8001 || !input_dev) {
err = -ENOMEM;
goto fail1;
}
w8001->serio = serio;
w8001->id = serio->id.id;
w8001->dev = input_dev;
init_completion(&w8001->cmd_done);
snprintf(w8001->phys, sizeof(w8001->phys), "%s/input0", serio->phys);
input_dev->name = "Wacom W8001 Penabled Serial TouchScreen";
input_dev->phys = w8001->phys;
input_dev->id.bustype = BUS_RS232;
input_dev->id.vendor = SERIO_W8001;
input_dev->id.product = w8001->id;
input_dev->id.version = 0x0100;
input_dev->dev.parent = &serio->dev;
input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
__set_bit(BTN_TOUCH, input_dev->keybit);
serio_set_drvdata(serio, w8001);
err = serio_open(serio, drv);
if (err)
goto fail2;
err = w8001_setup(w8001);
if (err)
goto fail3;
err = input_register_device(w8001->dev);
if (err)
goto fail3;
return 0;
fail3:
serio_close(serio);
fail2:
serio_set_drvdata(serio, NULL);
fail1:
input_free_device(input_dev);
kfree(w8001);
return err;
}
static struct serio_device_id w8001_serio_ids[] = {
{
.type = SERIO_RS232,
.proto = SERIO_W8001,
.id = SERIO_ANY,
.extra = SERIO_ANY,
},
{ 0 }
};
MODULE_DEVICE_TABLE(serio, w8001_serio_ids);
static struct serio_driver w8001_drv = {
.driver = {
.name = "w8001",
},
.description = DRIVER_DESC,
.id_table = w8001_serio_ids,
.interrupt = w8001_interrupt,
.connect = w8001_connect,
.disconnect = w8001_disconnect,
};
static int __init w8001_init(void)
{
return serio_register_driver(&w8001_drv);
}
static void __exit w8001_exit(void)
{
serio_unregister_driver(&w8001_drv);
}
module_init(w8001_init);
module_exit(w8001_exit);
