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* Atmel AT42QT1070 QTouch Sensor Controller
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* Copyright (C) 2011 Atmel
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* Authors: Bo Shen <voice.shen@atmel.com>
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* Base on AT42QT2160 driver by:
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* Raphael Derosso Pereira <raphaelpereira@gmail.com>
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/i2c.h>
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#include <linux/input.h>
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#include <linux/slab.h>
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#include <linux/irq.h>
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#include <linux/interrupt.h>
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#include <linux/jiffies.h>
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#include <linux/delay.h>
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/* Address for each register */
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#define QT1070_CHIP_ID 0x2E
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#define FW_VERSION 0x01
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#define QT1070_FW_VERSION 0x15
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#define DET_STATUS 0x02
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#define KEY_STATUS 0x03
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#define CALIBRATE_CMD 0x38
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#define QT1070_CAL_TIME 200
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#define QT1070_RESET_TIME 255
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/* AT42QT1070 support up to 7 keys */
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static const unsigned short qt1070_key2code[] = {
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KEY_0, KEY_1, KEY_2, KEY_3,
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struct i2c_client *client;
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struct input_dev *input;
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unsigned short keycodes[ARRAY_SIZE(qt1070_key2code)];
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static int qt1070_read(struct i2c_client *client, u8 reg)
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ret = i2c_smbus_read_byte_data(client, reg);
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"can not read register, returned %d\n", ret);
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static int qt1070_write(struct i2c_client *client, u8 reg, u8 data)
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ret = i2c_smbus_write_byte_data(client, reg, data);
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"can not write register, returned %d\n", ret);
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static bool __devinit qt1070_identify(struct i2c_client *client)
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id = qt1070_read(client, CHIP_ID);
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if (id != QT1070_CHIP_ID) {
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dev_err(&client->dev, "ID %d not supported\n", id);
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/* Read firmware version */
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ver = qt1070_read(client, FW_VERSION);
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dev_err(&client->dev, "could not read the firmware version\n");
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dev_info(&client->dev, "AT42QT1070 firmware version %x\n", ver);
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static irqreturn_t qt1070_interrupt(int irq, void *dev_id)
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struct qt1070_data *data = dev_id;
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struct i2c_client *client = data->client;
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struct input_dev *input = data->input;
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u8 new_keys, keyval, mask = 0x01;
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/* Read the detected status register, thus clearing interrupt */
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qt1070_read(client, DET_STATUS);
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/* Read which key changed */
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new_keys = qt1070_read(client, KEY_STATUS);
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for (i = 0; i < ARRAY_SIZE(qt1070_key2code); i++) {
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keyval = new_keys & mask;
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if ((data->last_keys & mask) != keyval)
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input_report_key(input, data->keycodes[i], keyval);
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data->last_keys = new_keys;
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static int __devinit qt1070_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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struct qt1070_data *data;
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struct input_dev *input;
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err = i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE);
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dev_err(&client->dev, "%s adapter not supported\n",
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dev_driver_string(&client->adapter->dev));
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dev_err(&client->dev, "please assign the irq to this device\n");
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/* Identify the qt1070 chip */
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if (!qt1070_identify(client))
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data = kzalloc(sizeof(struct qt1070_data), GFP_KERNEL);
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input = input_allocate_device();
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if (!data || !input) {
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dev_err(&client->dev, "insufficient memory\n");
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data->client = client;
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data->irq = client->irq;
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input->name = "AT42QT1070 QTouch Sensor";
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input->dev.parent = &client->dev;
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input->id.bustype = BUS_I2C;
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/* Add the keycode */
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input->keycode = data->keycodes;
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input->keycodesize = sizeof(data->keycodes[0]);
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input->keycodemax = ARRAY_SIZE(qt1070_key2code);
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__set_bit(EV_KEY, input->evbit);
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for (i = 0; i < ARRAY_SIZE(qt1070_key2code); i++) {
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data->keycodes[i] = qt1070_key2code[i];
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__set_bit(qt1070_key2code[i], input->keybit);
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/* Calibrate device */
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qt1070_write(client, CALIBRATE_CMD, 1);
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msleep(QT1070_CAL_TIME);
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qt1070_write(client, RESET, 1);
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msleep(QT1070_RESET_TIME);
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err = request_threaded_irq(client->irq, NULL, qt1070_interrupt,
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IRQF_TRIGGER_NONE, client->dev.driver->name, data);
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dev_err(&client->dev, "fail to request irq\n");
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/* Register the input device */
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err = input_register_device(data->input);
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dev_err(&client->dev, "Failed to register input device\n");
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i2c_set_clientdata(client, data);
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/* Read to clear the chang line */
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qt1070_read(client, DET_STATUS);
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free_irq(client->irq, data);
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input_free_device(input);
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static int __devexit qt1070_remove(struct i2c_client *client)
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struct qt1070_data *data = i2c_get_clientdata(client);
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free_irq(client->irq, data);
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input_unregister_device(data->input);
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i2c_set_clientdata(client, NULL);
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static const struct i2c_device_id qt1070_id[] = {
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MODULE_DEVICE_TABLE(i2c, qt1070_id);
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static struct i2c_driver qt1070_driver = {
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.owner = THIS_MODULE,
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.id_table = qt1070_id,
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.probe = qt1070_probe,
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.remove = __devexit_p(qt1070_remove),
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static int __init qt1070_init(void)
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return i2c_add_driver(&qt1070_driver);
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module_init(qt1070_init);
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static void __exit qt1070_exit(void)
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i2c_del_driver(&qt1070_driver);
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module_exit(qt1070_exit);
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MODULE_AUTHOR("Bo Shen <voice.shen@atmel.com>");
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MODULE_DESCRIPTION("Driver for AT42QT1070 QTouch sensor");
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MODULE_LICENSE("GPL");