/*
* Touch Screen driver for EETI's I2C connected touch screen panels
* Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
*
* See EETI's software guide for the protocol specification:
* http://home.eeti.com.tw/web20/eg/guide.htm
*
* Based on migor_ts.c
* Copyright (c) 2008 Magnus Damm
* Copyright (c) 2007 Ujjwal Pande <ujjwal@kenati.com>
*
* This file is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This file is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/timer.h>
#include <linux/gpio.h>
#include <linux/input/eeti_ts.h>
#include <linux/slab.h>
static int flip_x;
module_param(flip_x, bool, 0644);
MODULE_PARM_DESC(flip_x, "flip x coordinate");
static int flip_y;
module_param(flip_y, bool, 0644);
MODULE_PARM_DESC(flip_y, "flip y coordinate");
struct eeti_ts_priv {
struct i2c_client *client;
struct input_dev *input;
struct work_struct work;
struct mutex mutex;
int irq, irq_active_high;
};
#define EETI_TS_BITDEPTH (11)
#define EETI_MAXVAL ((1 << (EETI_TS_BITDEPTH + 1)) - 1)
#define REPORT_BIT_PRESSED (1 << 0)
#define REPORT_BIT_AD0 (1 << 1)
#define REPORT_BIT_AD1 (1 << 2)
#define REPORT_BIT_HAS_PRESSURE (1 << 6)
#define REPORT_RES_BITS(v) (((v) >> 1) + EETI_TS_BITDEPTH)
static inline int eeti_ts_irq_active(struct eeti_ts_priv *priv)
{
return gpio_get_value(irq_to_gpio(priv->irq)) == priv->irq_active_high;
}
static void eeti_ts_read(struct work_struct *work)
{
char buf[6];
unsigned int x, y, res, pressed, to = 100;
struct eeti_ts_priv *priv =
container_of(work, struct eeti_ts_priv, work);
mutex_lock(&priv->mutex);
while (eeti_ts_irq_active(priv) && --to)
i2c_master_recv(priv->client, buf, sizeof(buf));
if (!to) {
dev_err(&priv->client->dev,
"unable to clear IRQ - line stuck?\n");
goto out;
}
/* drop non-report packets */
if (!(buf[0] & 0x80))
goto out;
pressed = buf[0] & REPORT_BIT_PRESSED;
res = REPORT_RES_BITS(buf[0] & (REPORT_BIT_AD0 | REPORT_BIT_AD1));
x = buf[2] | (buf[1] << 8);
y = buf[4] | (buf[3] << 8);
/* fix the range to 11 bits */
x >>= res - EETI_TS_BITDEPTH;
y >>= res - EETI_TS_BITDEPTH;
if (flip_x)
x = EETI_MAXVAL - x;
if (flip_y)
y = EETI_MAXVAL - y;
if (buf[0] & REPORT_BIT_HAS_PRESSURE)
input_report_abs(priv->input, ABS_PRESSURE, buf[5]);
input_report_abs(priv->input, ABS_X, x);
input_report_abs(priv->input, ABS_Y, y);
input_report_key(priv->input, BTN_TOUCH, !!pressed);
input_sync(priv->input);
out:
mutex_unlock(&priv->mutex);
}
static irqreturn_t eeti_ts_isr(int irq, void *dev_id)
{
struct eeti_ts_priv *priv = dev_id;
/* postpone I2C transactions as we are atomic */
schedule_work(&priv->work);
return IRQ_HANDLED;
}
static int eeti_ts_open(struct input_dev *dev)
{
struct eeti_ts_priv *priv = input_get_drvdata(dev);
enable_irq(priv->irq);
/* Read the events once to arm the IRQ */
eeti_ts_read(&priv->work);
return 0;
}
static void eeti_ts_close(struct input_dev *dev)
{
struct eeti_ts_priv *priv = input_get_drvdata(dev);
disable_irq(priv->irq);
cancel_work_sync(&priv->work);
}
static int __devinit eeti_ts_probe(struct i2c_client *client,
const struct i2c_device_id *idp)
{
struct eeti_ts_platform_data *pdata;
struct eeti_ts_priv *priv;
struct input_dev *input;
unsigned int irq_flags;
int err = -ENOMEM;
/* In contrast to what's described in the datasheet, there seems
* to be no way of probing the presence of that device using I2C
* commands. So we need to blindly believe it is there, and wait
* for interrupts to occur. */
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (!priv) {
dev_err(&client->dev, "failed to allocate driver data\n");
goto err0;
}
mutex_init(&priv->mutex);
input = input_allocate_device();
if (!input) {
dev_err(&client->dev, "Failed to allocate input device.\n");
goto err1;
}
input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
input_set_abs_params(input, ABS_X, 0, EETI_MAXVAL, 0, 0);
input_set_abs_params(input, ABS_Y, 0, EETI_MAXVAL, 0, 0);
input_set_abs_params(input, ABS_PRESSURE, 0, 0xff, 0, 0);
input->name = client->name;
input->id.bustype = BUS_I2C;
input->dev.parent = &client->dev;
input->open = eeti_ts_open;
input->close = eeti_ts_close;
priv->client = client;
priv->input = input;
priv->irq = client->irq;
pdata = client->dev.platform_data;
if (pdata)
priv->irq_active_high = pdata->irq_active_high;
irq_flags = priv->irq_active_high ?
IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
INIT_WORK(&priv->work, eeti_ts_read);
i2c_set_clientdata(client, priv);
input_set_drvdata(input, priv);
err = input_register_device(input);
if (err)
goto err1;
err = request_irq(priv->irq, eeti_ts_isr, irq_flags,
client->name, priv);
if (err) {
dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
goto err2;
}
/* Disable the irq for now. It will be enabled once the input device
* is opened. */
disable_irq(priv->irq);
device_init_wakeup(&client->dev, 0);
return 0;
err2:
input_unregister_device(input);
input = NULL; /* so we dont try to free it below */
err1:
input_free_device(input);
i2c_set_clientdata(client, NULL);
kfree(priv);
err0:
return err;
}
static int __devexit eeti_ts_remove(struct i2c_client *client)
{
struct eeti_ts_priv *priv = i2c_get_clientdata(client);
free_irq(priv->irq, priv);
input_unregister_device(priv->input);
i2c_set_clientdata(client, NULL);
kfree(priv);
return 0;
}
#ifdef CONFIG_PM
static int eeti_ts_suspend(struct i2c_client *client, pm_message_t mesg)
{
struct eeti_ts_priv *priv = i2c_get_clientdata(client);
if (device_may_wakeup(&client->dev))
enable_irq_wake(priv->irq);
return 0;
}
static int eeti_ts_resume(struct i2c_client *client)
{
struct eeti_ts_priv *priv = i2c_get_clientdata(client);
if (device_may_wakeup(&client->dev))
disable_irq_wake(priv->irq);
return 0;
}
#else
#define eeti_ts_suspend NULL
#define eeti_ts_resume NULL
#endif
static const struct i2c_device_id eeti_ts_id[] = {
{ "eeti_ts", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, eeti_ts_id);
static struct i2c_driver eeti_ts_driver = {
.driver = {
.name = "eeti_ts",
},
.probe = eeti_ts_probe,
.remove = __devexit_p(eeti_ts_remove),
.suspend = eeti_ts_suspend,
.resume = eeti_ts_resume,
.id_table = eeti_ts_id,
};
static int __init eeti_ts_init(void)
{
return i2c_add_driver(&eeti_ts_driver);
}
static void __exit eeti_ts_exit(void)
{
i2c_del_driver(&eeti_ts_driver);
}
MODULE_DESCRIPTION("EETI Touchscreen driver");
MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
MODULE_LICENSE("GPL");
module_init(eeti_ts_init);
module_exit(eeti_ts_exit);
