/*
* Atmel AT42QT1070 QTouch Sensor Controller
*
* Copyright (C) 2011 Atmel
*
* Authors: Bo Shen <voice.shen@atmel.com>
*
* Base on AT42QT2160 driver by:
* Raphael Derosso Pereira <raphaelpereira@gmail.com>
* Copyright (C) 2009
*
* This program 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 program 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 program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/input.h>
#include <linux/slab.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/jiffies.h>
#include <linux/delay.h>
/* Address for each register */
#define CHIP_ID 0x00
#define QT1070_CHIP_ID 0x2E
#define FW_VERSION 0x01
#define QT1070_FW_VERSION 0x15
#define DET_STATUS 0x02
#define KEY_STATUS 0x03
/* Calibrate */
#define CALIBRATE_CMD 0x38
#define QT1070_CAL_TIME 200
/* Reset */
#define RESET 0x39
#define QT1070_RESET_TIME 255
/* AT42QT1070 support up to 7 keys */
static const unsigned short qt1070_key2code[] = {
KEY_0, KEY_1, KEY_2, KEY_3,
KEY_4, KEY_5, KEY_6,
};
struct qt1070_data {
struct i2c_client *client;
struct input_dev *input;
unsigned int irq;
unsigned short keycodes[ARRAY_SIZE(qt1070_key2code)];
u8 last_keys;
};
static int qt1070_read(struct i2c_client *client, u8 reg)
{
int ret;
ret = i2c_smbus_read_byte_data(client, reg);
if (ret < 0)
dev_err(&client->dev,
"can not read register, returned %d\n", ret);
return ret;
}
static int qt1070_write(struct i2c_client *client, u8 reg, u8 data)
{
int ret;
ret = i2c_smbus_write_byte_data(client, reg, data);
if (ret < 0)
dev_err(&client->dev,
"can not write register, returned %d\n", ret);
return ret;
}
static bool qt1070_identify(struct i2c_client *client)
{
int id, ver;
/* Read Chip ID */
id = qt1070_read(client, CHIP_ID);
if (id != QT1070_CHIP_ID) {
dev_err(&client->dev, "ID %d not supported\n", id);
return false;
}
/* Read firmware version */
ver = qt1070_read(client, FW_VERSION);
if (ver < 0) {
dev_err(&client->dev, "could not read the firmware version\n");
return false;
}
dev_info(&client->dev, "AT42QT1070 firmware version %x\n", ver);
return true;
}
static irqreturn_t qt1070_interrupt(int irq, void *dev_id)
{
struct qt1070_data *data = dev_id;
struct i2c_client *client = data->client;
struct input_dev *input = data->input;
int i;
u8 new_keys, keyval, mask = 0x01;
/* Read the detected status register, thus clearing interrupt */
qt1070_read(client, DET_STATUS);
/* Read which key changed */
new_keys = qt1070_read(client, KEY_STATUS);
for (i = 0; i < ARRAY_SIZE(qt1070_key2code); i++) {
keyval = new_keys & mask;
if ((data->last_keys & mask) != keyval)
input_report_key(input, data->keycodes[i], keyval);
mask <<= 1;
}
input_sync(input);
data->last_keys = new_keys;
return IRQ_HANDLED;
}
static int qt1070_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct qt1070_data *data;
struct input_dev *input;
int i;
int err;
err = i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE);
if (!err) {
dev_err(&client->dev, "%s adapter not supported\n",
dev_driver_string(&client->adapter->dev));
return -ENODEV;
}
if (!client->irq) {
dev_err(&client->dev, "please assign the irq to this device\n");
return -EINVAL;
}
/* Identify the qt1070 chip */
if (!qt1070_identify(client))
return -ENODEV;
data = kzalloc(sizeof(struct qt1070_data), GFP_KERNEL);
input = input_allocate_device();
if (!data || !input) {
dev_err(&client->dev, "insufficient memory\n");
err = -ENOMEM;
goto err_free_mem;
}
data->client = client;
data->input = input;
data->irq = client->irq;
input->name = "AT42QT1070 QTouch Sensor";
input->dev.parent = &client->dev;
input->id.bustype = BUS_I2C;
/* Add the keycode */
input->keycode = data->keycodes;
input->keycodesize = sizeof(data->keycodes[0]);
input->keycodemax = ARRAY_SIZE(qt1070_key2code);
__set_bit(EV_KEY, input->evbit);
for (i = 0; i < ARRAY_SIZE(qt1070_key2code); i++) {
data->keycodes[i] = qt1070_key2code[i];
__set_bit(qt1070_key2code[i], input->keybit);
}
/* Calibrate device */
qt1070_write(client, CALIBRATE_CMD, 1);
msleep(QT1070_CAL_TIME);
/* Soft reset */
qt1070_write(client, RESET, 1);
msleep(QT1070_RESET_TIME);
err = request_threaded_irq(client->irq, NULL, qt1070_interrupt,
IRQF_TRIGGER_NONE | IRQF_ONESHOT,
client->dev.driver->name, data);
if (err) {
dev_err(&client->dev, "fail to request irq\n");
goto err_free_mem;
}
/* Register the input device */
err = input_register_device(data->input);
if (err) {
dev_err(&client->dev, "Failed to register input device\n");
goto err_free_irq;
}
i2c_set_clientdata(client, data);
/* Read to clear the chang line */
qt1070_read(client, DET_STATUS);
return 0;
err_free_irq:
free_irq(client->irq, data);
err_free_mem:
input_free_device(input);
kfree(data);
return err;
}
static int qt1070_remove(struct i2c_client *client)
{
struct qt1070_data *data = i2c_get_clientdata(client);
/* Release IRQ */
free_irq(client->irq, data);
input_unregister_device(data->input);
kfree(data);
return 0;
}
static const struct i2c_device_id qt1070_id[] = {
{ "qt1070", 0 },
{ },
};
MODULE_DEVICE_TABLE(i2c, qt1070_id);
static struct i2c_driver qt1070_driver = {
.driver = {
.name = "qt1070",
.owner = THIS_MODULE,
},
.id_table = qt1070_id,
.probe = qt1070_probe,
.remove = qt1070_remove,
};
module_i2c_driver(qt1070_driver);
MODULE_AUTHOR("Bo Shen <voice.shen@atmel.com>");
MODULE_DESCRIPTION("Driver for AT42QT1070 QTouch sensor");
MODULE_LICENSE("GPL");
