drivers/input/keyboard/qt1070.c

   1 /*
   2  *  Atmel AT42QT1070 QTouch Sensor Controller
   3  *
   4  *  Copyright (C) 2011 Atmel
   5  *
   6  *  Authors: Bo Shen <voice.shen@atmel.com>
   7  *
   8  *  Base on AT42QT2160 driver by:
   9  *  Raphael Derosso Pereira <raphaelpereira@gmail.com>
  10  *  Copyright (C) 2009
  11  *
  12  *  This program is free software; you can redistribute it and/or modify
  13  *  it under the terms of the GNU General Public License as published by
  14  *  the Free Software Foundation; either version 2 of the License, or
  15  *  (at your option) any later version.
  16  *
  17  *  This program is distributed in the hope that it will be useful,
  18  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  *  GNU General Public License for more details.
  21  *
  22  *  You should have received a copy of the GNU General Public License
  23  *  along with this program; if not, write to the Free Software
  24  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  25  */
  26 #include <linux/kernel.h>
  27 #include <linux/module.h>
  28 #include <linux/init.h>
  29 #include <linux/i2c.h>
  30 #include <linux/input.h>
  31 #include <linux/slab.h>
  32 #include <linux/irq.h>
  33 #include <linux/interrupt.h>
  34 #include <linux/jiffies.h>
  35 #include <linux/delay.h>
  36
  37 /* Address for each register */
  38 #define CHIP_ID            0x00
  39 #define QT1070_CHIP_ID     0x2E
  40
  41 #define FW_VERSION         0x01
  42 #define QT1070_FW_VERSION  0x15
  43
  44 #define DET_STATUS         0x02
  45
  46 #define KEY_STATUS         0x03
  47
  48 /* Calibrate */
  49 #define CALIBRATE_CMD      0x38
  50 #define QT1070_CAL_TIME    200
  51
  52 /* Reset */
  53 #define RESET              0x39
  54 #define QT1070_RESET_TIME  255
  55
  56 /* AT42QT1070 support up to 7 keys */
  57 static const unsigned short qt1070_key2code[] = {
  58         KEY_0, KEY_1, KEY_2, KEY_3,
  59         KEY_4, KEY_5, KEY_6,
  60 };
  61
  62 struct qt1070_data {
  63         struct i2c_client *client;
  64         struct input_dev *input;
  65         unsigned int irq;
  66         unsigned short keycodes[ARRAY_SIZE(qt1070_key2code)];
  67         u8 last_keys;
  68 };
  69
  70 static int qt1070_read(struct i2c_client *client, u8 reg)
  71 {
  72         int ret;
  73
  74         ret = i2c_smbus_read_byte_data(client, reg);
  75         if (ret < 0)
  76                 dev_err(&client->dev,
  77                         "can not read register, returned %d\n", ret);
  78
  79         return ret;
  80 }
  81
  82 static int qt1070_write(struct i2c_client *client, u8 reg, u8 data)
  83 {
  84         int ret;
  85
  86         ret = i2c_smbus_write_byte_data(client, reg, data);
  87         if (ret < 0)
  88                 dev_err(&client->dev,
  89                         "can not write register, returned %d\n", ret);
  90
  91         return ret;
  92 }
  93
  94 static bool __devinit qt1070_identify(struct i2c_client *client)
  95 {
  96         int id, ver;
  97
  98         /* Read Chip ID */
  99         id = qt1070_read(client, CHIP_ID);
 100         if (id != QT1070_CHIP_ID) {
 101                 dev_err(&client->dev, "ID %d not supported\n", id);
 102                 return false;
 103         }
 104
 105         /* Read firmware version */
 106         ver = qt1070_read(client, FW_VERSION);
 107         if (ver < 0) {
 108                 dev_err(&client->dev, "could not read the firmware version\n");
 109                 return false;
 110         }
 111
 112         dev_info(&client->dev, "AT42QT1070 firmware version %x\n", ver);
 113
 114         return true;
 115 }
 116
 117 static irqreturn_t qt1070_interrupt(int irq, void *dev_id)
 118 {
 119         struct qt1070_data *data = dev_id;
 120         struct i2c_client *client = data->client;
 121         struct input_dev *input = data->input;
 122         int i;
 123         u8 new_keys, keyval, mask = 0x01;
 124
 125         /* Read the detected status register, thus clearing interrupt */
 126         qt1070_read(client, DET_STATUS);
 127
 128         /* Read which key changed */
 129         new_keys = qt1070_read(client, KEY_STATUS);
 130
 131         for (i = 0; i < ARRAY_SIZE(qt1070_key2code); i++) {
 132                 keyval = new_keys & mask;
 133                 if ((data->last_keys & mask) != keyval)
 134                         input_report_key(input, data->keycodes[i], keyval);
 135                 mask <<= 1;
 136         }
 137         input_sync(input);
 138
 139         data->last_keys = new_keys;
 140         return IRQ_HANDLED;
 141 }
 142
 143 static int __devinit qt1070_probe(struct i2c_client *client,
 144                                 const struct i2c_device_id *id)
 145 {
 146         struct qt1070_data *data;
 147         struct input_dev *input;
 148         int i;
 149         int err;
 150
 151         err = i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE);
 152         if (!err) {
 153                 dev_err(&client->dev, "%s adapter not supported\n",
 154                         dev_driver_string(&client->adapter->dev));
 155                 return -ENODEV;
 156         }
 157
 158         if (!client->irq) {
 159                 dev_err(&client->dev, "please assign the irq to this device\n");
 160                 return -EINVAL;
 161         }
 162
 163         /* Identify the qt1070 chip */
 164         if (!qt1070_identify(client))
 165                 return -ENODEV;
 166
 167         data = kzalloc(sizeof(struct qt1070_data), GFP_KERNEL);
 168         input = input_allocate_device();
 169         if (!data || !input) {
 170                 dev_err(&client->dev, "insufficient memory\n");
 171                 err = -ENOMEM;
 172                 goto err_free_mem;
 173         }
 174
 175         data->client = client;
 176         data->input = input;
 177         data->irq = client->irq;
 178
 179         input->name = "AT42QT1070 QTouch Sensor";
 180         input->dev.parent = &client->dev;
 181         input->id.bustype = BUS_I2C;
 182
 183         /* Add the keycode */
 184         input->keycode = data->keycodes;
 185         input->keycodesize = sizeof(data->keycodes[0]);
 186         input->keycodemax = ARRAY_SIZE(qt1070_key2code);
 187
 188         __set_bit(EV_KEY, input->evbit);
 189
 190         for (i = 0; i < ARRAY_SIZE(qt1070_key2code); i++) {
 191                 data->keycodes[i] = qt1070_key2code[i];
 192                 __set_bit(qt1070_key2code[i], input->keybit);
 193         }
 194
 195         /* Calibrate device */
 196         qt1070_write(client, CALIBRATE_CMD, 1);
 197         msleep(QT1070_CAL_TIME);
 198
 199         /* Soft reset */
 200         qt1070_write(client, RESET, 1);
 201         msleep(QT1070_RESET_TIME);
 202
 203         err = request_threaded_irq(client->irq, NULL, qt1070_interrupt,
 204                 IRQF_TRIGGER_NONE, client->dev.driver->name, data);
 205         if (err) {
 206                 dev_err(&client->dev, "fail to request irq\n");
 207                 goto err_free_mem;
 208         }
 209
 210         /* Register the input device */
 211         err = input_register_device(data->input);
 212         if (err) {
 213                 dev_err(&client->dev, "Failed to register input device\n");
 214                 goto err_free_irq;
 215         }
 216
 217         i2c_set_clientdata(client, data);
 218
 219         /* Read to clear the chang line */
 220         qt1070_read(client, DET_STATUS);
 221
 222         return 0;
 223
 224 err_free_irq:
 225         free_irq(client->irq, data);
 226 err_free_mem:
 227         input_free_device(input);
 228         kfree(data);
 229         return err;
 230 }
 231
 232 static int __devexit qt1070_remove(struct i2c_client *client)
 233 {
 234         struct qt1070_data *data = i2c_get_clientdata(client);
 235
 236         /* Release IRQ */
 237         free_irq(client->irq, data);
 238
 239         input_unregister_device(data->input);
 240         kfree(data);
 241
 242         i2c_set_clientdata(client, NULL);
 243
 244         return 0;
 245 }
 246
 247 static const struct i2c_device_id qt1070_id[] = {
 248         { "qt1070", 0 },
 249         { },
 250 };
 251 MODULE_DEVICE_TABLE(i2c, qt1070_id);
 252
 253 static struct i2c_driver qt1070_driver = {
 254         .driver = {
 255                 .name   = "qt1070",
 256                 .owner  = THIS_MODULE,
 257         },
 258         .id_table       = qt1070_id,
 259         .probe          = qt1070_probe,
 260         .remove         = __devexit_p(qt1070_remove),
 261 };
 262
 263 static int __init qt1070_init(void)
 264 {
 265         return i2c_add_driver(&qt1070_driver);
 266 }
 267 module_init(qt1070_init);
 268
 269 static void __exit qt1070_exit(void)
 270 {
 271         i2c_del_driver(&qt1070_driver);
 272 }
 273 module_exit(qt1070_exit);
 274
 275 MODULE_AUTHOR("Bo Shen <voice.shen@atmel.com>");
 276 MODULE_DESCRIPTION("Driver for AT42QT1070 QTouch sensor");
 277 MODULE_LICENSE("GPL");