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/i2c.h> 29 #include <linux/input.h> 30 #include <linux/slab.h> 31 #include <linux/irq.h> 32 #include <linux/interrupt.h> 33 #include <linux/jiffies.h> 34 #include <linux/delay.h> 35 36 /* Address for each register */ 37 #define CHIP_ID 0x00 38 #define QT1070_CHIP_ID 0x2E 39 40 #define FW_VERSION 0x01 41 #define QT1070_FW_VERSION 0x15 42 43 #define DET_STATUS 0x02 44 45 #define KEY_STATUS 0x03 46 47 /* Calibrate */ 48 #define CALIBRATE_CMD 0x38 49 #define QT1070_CAL_TIME 200 50 51 /* Reset */ 52 #define RESET 0x39 53 #define QT1070_RESET_TIME 255 54 55 /* AT42QT1070 support up to 7 keys */ 56 static const unsigned short qt1070_key2code[] = { 57 KEY_0, KEY_1, KEY_2, KEY_3, 58 KEY_4, KEY_5, KEY_6, 59 }; 60 61 struct qt1070_data { 62 struct i2c_client *client; 63 struct input_dev *input; 64 unsigned int irq; 65 unsigned short keycodes[ARRAY_SIZE(qt1070_key2code)]; 66 u8 last_keys; 67 }; 68 69 static int qt1070_read(struct i2c_client *client, u8 reg) 70 { 71 int ret; 72 73 ret = i2c_smbus_read_byte_data(client, reg); 74 if (ret < 0) 75 dev_err(&client->dev, 76 "can not read register, returned %d\n", ret); 77 78 return ret; 79 } 80 81 static int qt1070_write(struct i2c_client *client, u8 reg, u8 data) 82 { 83 int ret; 84 85 ret = i2c_smbus_write_byte_data(client, reg, data); 86 if (ret < 0) 87 dev_err(&client->dev, 88 "can not write register, returned %d\n", ret); 89 90 return ret; 91 } 92 93 static bool qt1070_identify(struct i2c_client *client) 94 { 95 int id, ver; 96 97 /* Read Chip ID */ 98 id = qt1070_read(client, CHIP_ID); 99 if (id != QT1070_CHIP_ID) { 100 dev_err(&client->dev, "ID %d not supported\n", id); 101 return false; 102 } 103 104 /* Read firmware version */ 105 ver = qt1070_read(client, FW_VERSION); 106 if (ver < 0) { 107 dev_err(&client->dev, "could not read the firmware version\n"); 108 return false; 109 } 110 111 dev_info(&client->dev, "AT42QT1070 firmware version %x\n", ver); 112 113 return true; 114 } 115 116 static irqreturn_t qt1070_interrupt(int irq, void *dev_id) 117 { 118 struct qt1070_data *data = dev_id; 119 struct i2c_client *client = data->client; 120 struct input_dev *input = data->input; 121 int i; 122 u8 new_keys, keyval, mask = 0x01; 123 124 /* Read the detected status register, thus clearing interrupt */ 125 qt1070_read(client, DET_STATUS); 126 127 /* Read which key changed */ 128 new_keys = qt1070_read(client, KEY_STATUS); 129 130 for (i = 0; i < ARRAY_SIZE(qt1070_key2code); i++) { 131 keyval = new_keys & mask; 132 if ((data->last_keys & mask) != keyval) 133 input_report_key(input, data->keycodes[i], keyval); 134 mask <<= 1; 135 } 136 input_sync(input); 137 138 data->last_keys = new_keys; 139 return IRQ_HANDLED; 140 } 141 142 static int qt1070_probe(struct i2c_client *client, 143 const struct i2c_device_id *id) 144 { 145 struct qt1070_data *data; 146 struct input_dev *input; 147 int i; 148 int err; 149 150 err = i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE); 151 if (!err) { 152 dev_err(&client->dev, "%s adapter not supported\n", 153 dev_driver_string(&client->adapter->dev)); 154 return -ENODEV; 155 } 156 157 if (!client->irq) { 158 dev_err(&client->dev, "please assign the irq to this device\n"); 159 return -EINVAL; 160 } 161 162 /* Identify the qt1070 chip */ 163 if (!qt1070_identify(client)) 164 return -ENODEV; 165 166 data = kzalloc(sizeof(struct qt1070_data), GFP_KERNEL); 167 input = input_allocate_device(); 168 if (!data || !input) { 169 dev_err(&client->dev, "insufficient memory\n"); 170 err = -ENOMEM; 171 goto err_free_mem; 172 } 173 174 data->client = client; 175 data->input = input; 176 data->irq = client->irq; 177 178 input->name = "AT42QT1070 QTouch Sensor"; 179 input->dev.parent = &client->dev; 180 input->id.bustype = BUS_I2C; 181 182 /* Add the keycode */ 183 input->keycode = data->keycodes; 184 input->keycodesize = sizeof(data->keycodes[0]); 185 input->keycodemax = ARRAY_SIZE(qt1070_key2code); 186 187 __set_bit(EV_KEY, input->evbit); 188 189 for (i = 0; i < ARRAY_SIZE(qt1070_key2code); i++) { 190 data->keycodes[i] = qt1070_key2code[i]; 191 __set_bit(qt1070_key2code[i], input->keybit); 192 } 193 194 /* Calibrate device */ 195 qt1070_write(client, CALIBRATE_CMD, 1); 196 msleep(QT1070_CAL_TIME); 197 198 /* Soft reset */ 199 qt1070_write(client, RESET, 1); 200 msleep(QT1070_RESET_TIME); 201 202 err = request_threaded_irq(client->irq, NULL, qt1070_interrupt, 203 IRQF_TRIGGER_NONE | IRQF_ONESHOT, 204 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 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 return 0; 243 } 244 245 #ifdef CONFIG_PM_SLEEP 246 static int qt1070_suspend(struct device *dev) 247 { 248 struct i2c_client *client = to_i2c_client(dev); 249 struct qt1070_data *data = i2c_get_clientdata(client); 250 251 if (device_may_wakeup(dev)) 252 enable_irq_wake(data->irq); 253 254 return 0; 255 } 256 257 static int qt1070_resume(struct device *dev) 258 { 259 struct i2c_client *client = to_i2c_client(dev); 260 struct qt1070_data *data = i2c_get_clientdata(client); 261 262 if (device_may_wakeup(dev)) 263 disable_irq_wake(data->irq); 264 265 return 0; 266 } 267 #endif 268 269 static SIMPLE_DEV_PM_OPS(qt1070_pm_ops, qt1070_suspend, qt1070_resume); 270 271 static const struct i2c_device_id qt1070_id[] = { 272 { "qt1070", 0 }, 273 { }, 274 }; 275 MODULE_DEVICE_TABLE(i2c, qt1070_id); 276 277 static struct i2c_driver qt1070_driver = { 278 .driver = { 279 .name = "qt1070", 280 .pm = &qt1070_pm_ops, 281 }, 282 .id_table = qt1070_id, 283 .probe = qt1070_probe, 284 .remove = qt1070_remove, 285 }; 286 287 module_i2c_driver(qt1070_driver); 288 289 MODULE_AUTHOR("Bo Shen <voice.shen@atmel.com>"); 290 MODULE_DESCRIPTION("Driver for AT42QT1070 QTouch sensor"); 291 MODULE_LICENSE("GPL"); 292