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 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 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 | IRQF_ONESHOT, 205 client->dev.driver->name, data); 206 if (err) { 207 dev_err(&client->dev, "fail to request irq\n"); 208 goto err_free_mem; 209 } 210 211 /* Register the input device */ 212 err = input_register_device(data->input); 213 if (err) { 214 dev_err(&client->dev, "Failed to register input device\n"); 215 goto err_free_irq; 216 } 217 218 i2c_set_clientdata(client, data); 219 220 /* Read to clear the chang line */ 221 qt1070_read(client, DET_STATUS); 222 223 return 0; 224 225 err_free_irq: 226 free_irq(client->irq, data); 227 err_free_mem: 228 input_free_device(input); 229 kfree(data); 230 return err; 231 } 232 233 static int qt1070_remove(struct i2c_client *client) 234 { 235 struct qt1070_data *data = i2c_get_clientdata(client); 236 237 /* Release IRQ */ 238 free_irq(client->irq, data); 239 240 input_unregister_device(data->input); 241 kfree(data); 242 243 return 0; 244 } 245 246 #ifdef CONFIG_PM_SLEEP 247 static int qt1070_suspend(struct device *dev) 248 { 249 struct i2c_client *client = to_i2c_client(dev); 250 struct qt1070_data *data = i2c_get_clientdata(client); 251 252 if (device_may_wakeup(dev)) 253 enable_irq_wake(data->irq); 254 255 return 0; 256 } 257 258 static int qt1070_resume(struct device *dev) 259 { 260 struct i2c_client *client = to_i2c_client(dev); 261 struct qt1070_data *data = i2c_get_clientdata(client); 262 263 if (device_may_wakeup(dev)) 264 disable_irq_wake(data->irq); 265 266 return 0; 267 } 268 #endif 269 270 static SIMPLE_DEV_PM_OPS(qt1070_pm_ops, qt1070_suspend, qt1070_resume); 271 272 static const struct i2c_device_id qt1070_id[] = { 273 { "qt1070", 0 }, 274 { }, 275 }; 276 MODULE_DEVICE_TABLE(i2c, qt1070_id); 277 278 static struct i2c_driver qt1070_driver = { 279 .driver = { 280 .name = "qt1070", 281 .owner = THIS_MODULE, 282 .pm = &qt1070_pm_ops, 283 }, 284 .id_table = qt1070_id, 285 .probe = qt1070_probe, 286 .remove = qt1070_remove, 287 }; 288 289 module_i2c_driver(qt1070_driver); 290 291 MODULE_AUTHOR("Bo Shen <voice.shen@atmel.com>"); 292 MODULE_DESCRIPTION("Driver for AT42QT1070 QTouch sensor"); 293 MODULE_LICENSE("GPL"); 294