1 /* 2 * Input driver for Microchip CAP11xx based capacitive touch sensors 3 * 4 * (c) 2014 Daniel Mack <linux@zonque.org> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <linux/interrupt.h> 14 #include <linux/input.h> 15 #include <linux/leds.h> 16 #include <linux/of_irq.h> 17 #include <linux/regmap.h> 18 #include <linux/i2c.h> 19 #include <linux/gpio/consumer.h> 20 21 #define CAP11XX_REG_MAIN_CONTROL 0x00 22 #define CAP11XX_REG_MAIN_CONTROL_GAIN_SHIFT (6) 23 #define CAP11XX_REG_MAIN_CONTROL_GAIN_MASK (0xc0) 24 #define CAP11XX_REG_MAIN_CONTROL_DLSEEP BIT(4) 25 #define CAP11XX_REG_GENERAL_STATUS 0x02 26 #define CAP11XX_REG_SENSOR_INPUT 0x03 27 #define CAP11XX_REG_NOISE_FLAG_STATUS 0x0a 28 #define CAP11XX_REG_SENOR_DELTA(X) (0x10 + (X)) 29 #define CAP11XX_REG_SENSITIVITY_CONTROL 0x1f 30 #define CAP11XX_REG_CONFIG 0x20 31 #define CAP11XX_REG_SENSOR_ENABLE 0x21 32 #define CAP11XX_REG_SENSOR_CONFIG 0x22 33 #define CAP11XX_REG_SENSOR_CONFIG2 0x23 34 #define CAP11XX_REG_SAMPLING_CONFIG 0x24 35 #define CAP11XX_REG_CALIBRATION 0x26 36 #define CAP11XX_REG_INT_ENABLE 0x27 37 #define CAP11XX_REG_REPEAT_RATE 0x28 38 #define CAP11XX_REG_MT_CONFIG 0x2a 39 #define CAP11XX_REG_MT_PATTERN_CONFIG 0x2b 40 #define CAP11XX_REG_MT_PATTERN 0x2d 41 #define CAP11XX_REG_RECALIB_CONFIG 0x2f 42 #define CAP11XX_REG_SENSOR_THRESH(X) (0x30 + (X)) 43 #define CAP11XX_REG_SENSOR_NOISE_THRESH 0x38 44 #define CAP11XX_REG_STANDBY_CHANNEL 0x40 45 #define CAP11XX_REG_STANDBY_CONFIG 0x41 46 #define CAP11XX_REG_STANDBY_SENSITIVITY 0x42 47 #define CAP11XX_REG_STANDBY_THRESH 0x43 48 #define CAP11XX_REG_CONFIG2 0x44 49 #define CAP11XX_REG_CONFIG2_ALT_POL BIT(6) 50 #define CAP11XX_REG_SENSOR_BASE_CNT(X) (0x50 + (X)) 51 #define CAP11XX_REG_LED_POLARITY 0x73 52 #define CAP11XX_REG_LED_OUTPUT_CONTROL 0x74 53 54 #define CAP11XX_REG_LED_DUTY_CYCLE_1 0x90 55 #define CAP11XX_REG_LED_DUTY_CYCLE_2 0x91 56 #define CAP11XX_REG_LED_DUTY_CYCLE_3 0x92 57 #define CAP11XX_REG_LED_DUTY_CYCLE_4 0x93 58 59 #define CAP11XX_REG_LED_DUTY_MIN_MASK (0x0f) 60 #define CAP11XX_REG_LED_DUTY_MIN_MASK_SHIFT (0) 61 #define CAP11XX_REG_LED_DUTY_MAX_MASK (0xf0) 62 #define CAP11XX_REG_LED_DUTY_MAX_MASK_SHIFT (4) 63 #define CAP11XX_REG_LED_DUTY_MAX_VALUE (15) 64 65 #define CAP11XX_REG_SENSOR_CALIB (0xb1 + (X)) 66 #define CAP11XX_REG_SENSOR_CALIB_LSB1 0xb9 67 #define CAP11XX_REG_SENSOR_CALIB_LSB2 0xba 68 #define CAP11XX_REG_PRODUCT_ID 0xfd 69 #define CAP11XX_REG_MANUFACTURER_ID 0xfe 70 #define CAP11XX_REG_REVISION 0xff 71 72 #define CAP11XX_MANUFACTURER_ID 0x5d 73 74 #ifdef CONFIG_LEDS_CLASS 75 struct cap11xx_led { 76 struct cap11xx_priv *priv; 77 struct led_classdev cdev; 78 struct work_struct work; 79 u32 reg; 80 enum led_brightness new_brightness; 81 }; 82 #endif 83 84 struct cap11xx_priv { 85 struct regmap *regmap; 86 struct input_dev *idev; 87 88 struct cap11xx_led *leds; 89 int num_leds; 90 91 /* config */ 92 u32 keycodes[]; 93 }; 94 95 struct cap11xx_hw_model { 96 u8 product_id; 97 unsigned int num_channels; 98 unsigned int num_leds; 99 }; 100 101 enum { 102 CAP1106, 103 CAP1126, 104 CAP1188, 105 }; 106 107 static const struct cap11xx_hw_model cap11xx_devices[] = { 108 [CAP1106] = { .product_id = 0x55, .num_channels = 6, .num_leds = 0 }, 109 [CAP1126] = { .product_id = 0x53, .num_channels = 6, .num_leds = 2 }, 110 [CAP1188] = { .product_id = 0x50, .num_channels = 8, .num_leds = 8 }, 111 }; 112 113 static const struct reg_default cap11xx_reg_defaults[] = { 114 { CAP11XX_REG_MAIN_CONTROL, 0x00 }, 115 { CAP11XX_REG_GENERAL_STATUS, 0x00 }, 116 { CAP11XX_REG_SENSOR_INPUT, 0x00 }, 117 { CAP11XX_REG_NOISE_FLAG_STATUS, 0x00 }, 118 { CAP11XX_REG_SENSITIVITY_CONTROL, 0x2f }, 119 { CAP11XX_REG_CONFIG, 0x20 }, 120 { CAP11XX_REG_SENSOR_ENABLE, 0x3f }, 121 { CAP11XX_REG_SENSOR_CONFIG, 0xa4 }, 122 { CAP11XX_REG_SENSOR_CONFIG2, 0x07 }, 123 { CAP11XX_REG_SAMPLING_CONFIG, 0x39 }, 124 { CAP11XX_REG_CALIBRATION, 0x00 }, 125 { CAP11XX_REG_INT_ENABLE, 0x3f }, 126 { CAP11XX_REG_REPEAT_RATE, 0x3f }, 127 { CAP11XX_REG_MT_CONFIG, 0x80 }, 128 { CAP11XX_REG_MT_PATTERN_CONFIG, 0x00 }, 129 { CAP11XX_REG_MT_PATTERN, 0x3f }, 130 { CAP11XX_REG_RECALIB_CONFIG, 0x8a }, 131 { CAP11XX_REG_SENSOR_THRESH(0), 0x40 }, 132 { CAP11XX_REG_SENSOR_THRESH(1), 0x40 }, 133 { CAP11XX_REG_SENSOR_THRESH(2), 0x40 }, 134 { CAP11XX_REG_SENSOR_THRESH(3), 0x40 }, 135 { CAP11XX_REG_SENSOR_THRESH(4), 0x40 }, 136 { CAP11XX_REG_SENSOR_THRESH(5), 0x40 }, 137 { CAP11XX_REG_SENSOR_NOISE_THRESH, 0x01 }, 138 { CAP11XX_REG_STANDBY_CHANNEL, 0x00 }, 139 { CAP11XX_REG_STANDBY_CONFIG, 0x39 }, 140 { CAP11XX_REG_STANDBY_SENSITIVITY, 0x02 }, 141 { CAP11XX_REG_STANDBY_THRESH, 0x40 }, 142 { CAP11XX_REG_CONFIG2, 0x40 }, 143 { CAP11XX_REG_LED_POLARITY, 0x00 }, 144 { CAP11XX_REG_SENSOR_CALIB_LSB1, 0x00 }, 145 { CAP11XX_REG_SENSOR_CALIB_LSB2, 0x00 }, 146 }; 147 148 static bool cap11xx_volatile_reg(struct device *dev, unsigned int reg) 149 { 150 switch (reg) { 151 case CAP11XX_REG_MAIN_CONTROL: 152 case CAP11XX_REG_SENSOR_INPUT: 153 case CAP11XX_REG_SENOR_DELTA(0): 154 case CAP11XX_REG_SENOR_DELTA(1): 155 case CAP11XX_REG_SENOR_DELTA(2): 156 case CAP11XX_REG_SENOR_DELTA(3): 157 case CAP11XX_REG_SENOR_DELTA(4): 158 case CAP11XX_REG_SENOR_DELTA(5): 159 case CAP11XX_REG_PRODUCT_ID: 160 case CAP11XX_REG_MANUFACTURER_ID: 161 case CAP11XX_REG_REVISION: 162 return true; 163 } 164 165 return false; 166 } 167 168 static const struct regmap_config cap11xx_regmap_config = { 169 .reg_bits = 8, 170 .val_bits = 8, 171 172 .max_register = CAP11XX_REG_REVISION, 173 .reg_defaults = cap11xx_reg_defaults, 174 175 .num_reg_defaults = ARRAY_SIZE(cap11xx_reg_defaults), 176 .cache_type = REGCACHE_RBTREE, 177 .volatile_reg = cap11xx_volatile_reg, 178 }; 179 180 static irqreturn_t cap11xx_thread_func(int irq_num, void *data) 181 { 182 struct cap11xx_priv *priv = data; 183 unsigned int status; 184 int ret, i; 185 186 /* 187 * Deassert interrupt. This needs to be done before reading the status 188 * registers, which will not carry valid values otherwise. 189 */ 190 ret = regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL, 1, 0); 191 if (ret < 0) 192 goto out; 193 194 ret = regmap_read(priv->regmap, CAP11XX_REG_SENSOR_INPUT, &status); 195 if (ret < 0) 196 goto out; 197 198 for (i = 0; i < priv->idev->keycodemax; i++) 199 input_report_key(priv->idev, priv->keycodes[i], 200 status & (1 << i)); 201 202 input_sync(priv->idev); 203 204 out: 205 return IRQ_HANDLED; 206 } 207 208 static int cap11xx_set_sleep(struct cap11xx_priv *priv, bool sleep) 209 { 210 /* 211 * DLSEEP mode will turn off all LEDS, prevent this 212 */ 213 if (IS_ENABLED(CONFIG_LEDS_CLASS) && priv->num_leds) 214 return 0; 215 216 return regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL, 217 CAP11XX_REG_MAIN_CONTROL_DLSEEP, 218 sleep ? CAP11XX_REG_MAIN_CONTROL_DLSEEP : 0); 219 } 220 221 static int cap11xx_input_open(struct input_dev *idev) 222 { 223 struct cap11xx_priv *priv = input_get_drvdata(idev); 224 225 return cap11xx_set_sleep(priv, false); 226 } 227 228 static void cap11xx_input_close(struct input_dev *idev) 229 { 230 struct cap11xx_priv *priv = input_get_drvdata(idev); 231 232 cap11xx_set_sleep(priv, true); 233 } 234 235 #ifdef CONFIG_LEDS_CLASS 236 static void cap11xx_led_work(struct work_struct *work) 237 { 238 struct cap11xx_led *led = container_of(work, struct cap11xx_led, work); 239 struct cap11xx_priv *priv = led->priv; 240 int value = led->new_brightness; 241 242 /* 243 * All LEDs share the same duty cycle as this is a HW limitation. 244 * Brightness levels per LED are either 0 (OFF) and 1 (ON). 245 */ 246 regmap_update_bits(priv->regmap, CAP11XX_REG_LED_OUTPUT_CONTROL, 247 BIT(led->reg), value ? BIT(led->reg) : 0); 248 } 249 250 static void cap11xx_led_set(struct led_classdev *cdev, 251 enum led_brightness value) 252 { 253 struct cap11xx_led *led = container_of(cdev, struct cap11xx_led, cdev); 254 255 if (led->new_brightness == value) 256 return; 257 258 led->new_brightness = value; 259 schedule_work(&led->work); 260 } 261 262 static int cap11xx_init_leds(struct device *dev, 263 struct cap11xx_priv *priv, int num_leds) 264 { 265 struct device_node *node = dev->of_node, *child; 266 struct cap11xx_led *led; 267 int cnt = of_get_child_count(node); 268 int error; 269 270 if (!num_leds || !cnt) 271 return 0; 272 273 if (cnt > num_leds) 274 return -EINVAL; 275 276 led = devm_kcalloc(dev, cnt, sizeof(struct cap11xx_led), GFP_KERNEL); 277 if (!led) 278 return -ENOMEM; 279 280 priv->leds = led; 281 282 error = regmap_update_bits(priv->regmap, 283 CAP11XX_REG_LED_OUTPUT_CONTROL, 0xff, 0); 284 if (error) 285 return error; 286 287 error = regmap_update_bits(priv->regmap, CAP11XX_REG_LED_DUTY_CYCLE_4, 288 CAP11XX_REG_LED_DUTY_MAX_MASK, 289 CAP11XX_REG_LED_DUTY_MAX_VALUE << 290 CAP11XX_REG_LED_DUTY_MAX_MASK_SHIFT); 291 if (error) 292 return error; 293 294 for_each_child_of_node(node, child) { 295 u32 reg; 296 297 led->cdev.name = 298 of_get_property(child, "label", NULL) ? : child->name; 299 led->cdev.default_trigger = 300 of_get_property(child, "linux,default-trigger", NULL); 301 led->cdev.flags = 0; 302 led->cdev.brightness_set = cap11xx_led_set; 303 led->cdev.max_brightness = 1; 304 led->cdev.brightness = LED_OFF; 305 306 error = of_property_read_u32(child, "reg", ®); 307 if (error != 0 || reg >= num_leds) { 308 of_node_put(child); 309 return -EINVAL; 310 } 311 312 led->reg = reg; 313 led->priv = priv; 314 315 INIT_WORK(&led->work, cap11xx_led_work); 316 317 error = devm_led_classdev_register(dev, &led->cdev); 318 if (error) { 319 of_node_put(child); 320 return error; 321 } 322 323 priv->num_leds++; 324 led++; 325 } 326 327 return 0; 328 } 329 #else 330 static int cap11xx_init_leds(struct device *dev, 331 struct cap11xx_priv *priv, int num_leds) 332 { 333 return 0; 334 } 335 #endif 336 337 static int cap11xx_i2c_probe(struct i2c_client *i2c_client, 338 const struct i2c_device_id *id) 339 { 340 struct device *dev = &i2c_client->dev; 341 struct cap11xx_priv *priv; 342 struct device_node *node; 343 const struct cap11xx_hw_model *cap; 344 int i, error, irq, gain = 0; 345 unsigned int val, rev; 346 u32 gain32; 347 348 if (id->driver_data >= ARRAY_SIZE(cap11xx_devices)) { 349 dev_err(dev, "Invalid device ID %lu\n", id->driver_data); 350 return -EINVAL; 351 } 352 353 cap = &cap11xx_devices[id->driver_data]; 354 if (!cap || !cap->num_channels) { 355 dev_err(dev, "Invalid device configuration\n"); 356 return -EINVAL; 357 } 358 359 priv = devm_kzalloc(dev, 360 struct_size(priv, keycodes, cap->num_channels), 361 GFP_KERNEL); 362 if (!priv) 363 return -ENOMEM; 364 365 priv->regmap = devm_regmap_init_i2c(i2c_client, &cap11xx_regmap_config); 366 if (IS_ERR(priv->regmap)) 367 return PTR_ERR(priv->regmap); 368 369 error = regmap_read(priv->regmap, CAP11XX_REG_PRODUCT_ID, &val); 370 if (error) 371 return error; 372 373 if (val != cap->product_id) { 374 dev_err(dev, "Product ID: Got 0x%02x, expected 0x%02x\n", 375 val, cap->product_id); 376 return -ENXIO; 377 } 378 379 error = regmap_read(priv->regmap, CAP11XX_REG_MANUFACTURER_ID, &val); 380 if (error) 381 return error; 382 383 if (val != CAP11XX_MANUFACTURER_ID) { 384 dev_err(dev, "Manufacturer ID: Got 0x%02x, expected 0x%02x\n", 385 val, CAP11XX_MANUFACTURER_ID); 386 return -ENXIO; 387 } 388 389 error = regmap_read(priv->regmap, CAP11XX_REG_REVISION, &rev); 390 if (error < 0) 391 return error; 392 393 dev_info(dev, "CAP11XX detected, revision 0x%02x\n", rev); 394 node = dev->of_node; 395 396 if (!of_property_read_u32(node, "microchip,sensor-gain", &gain32)) { 397 if (is_power_of_2(gain32) && gain32 <= 8) 398 gain = ilog2(gain32); 399 else 400 dev_err(dev, "Invalid sensor-gain value %d\n", gain32); 401 } 402 403 if (of_property_read_bool(node, "microchip,irq-active-high")) { 404 error = regmap_update_bits(priv->regmap, CAP11XX_REG_CONFIG2, 405 CAP11XX_REG_CONFIG2_ALT_POL, 0); 406 if (error) 407 return error; 408 } 409 410 /* Provide some useful defaults */ 411 for (i = 0; i < cap->num_channels; i++) 412 priv->keycodes[i] = KEY_A + i; 413 414 of_property_read_u32_array(node, "linux,keycodes", 415 priv->keycodes, cap->num_channels); 416 417 error = regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL, 418 CAP11XX_REG_MAIN_CONTROL_GAIN_MASK, 419 gain << CAP11XX_REG_MAIN_CONTROL_GAIN_SHIFT); 420 if (error) 421 return error; 422 423 /* Disable autorepeat. The Linux input system has its own handling. */ 424 error = regmap_write(priv->regmap, CAP11XX_REG_REPEAT_RATE, 0); 425 if (error) 426 return error; 427 428 priv->idev = devm_input_allocate_device(dev); 429 if (!priv->idev) 430 return -ENOMEM; 431 432 priv->idev->name = "CAP11XX capacitive touch sensor"; 433 priv->idev->id.bustype = BUS_I2C; 434 priv->idev->evbit[0] = BIT_MASK(EV_KEY); 435 436 if (of_property_read_bool(node, "autorepeat")) 437 __set_bit(EV_REP, priv->idev->evbit); 438 439 for (i = 0; i < cap->num_channels; i++) 440 __set_bit(priv->keycodes[i], priv->idev->keybit); 441 442 __clear_bit(KEY_RESERVED, priv->idev->keybit); 443 444 priv->idev->keycode = priv->keycodes; 445 priv->idev->keycodesize = sizeof(priv->keycodes[0]); 446 priv->idev->keycodemax = cap->num_channels; 447 448 priv->idev->id.vendor = CAP11XX_MANUFACTURER_ID; 449 priv->idev->id.product = cap->product_id; 450 priv->idev->id.version = rev; 451 452 priv->idev->open = cap11xx_input_open; 453 priv->idev->close = cap11xx_input_close; 454 455 error = cap11xx_init_leds(dev, priv, cap->num_leds); 456 if (error) 457 return error; 458 459 input_set_drvdata(priv->idev, priv); 460 461 /* 462 * Put the device in deep sleep mode for now. 463 * ->open() will bring it back once the it is actually needed. 464 */ 465 cap11xx_set_sleep(priv, true); 466 467 error = input_register_device(priv->idev); 468 if (error) 469 return error; 470 471 irq = irq_of_parse_and_map(node, 0); 472 if (!irq) { 473 dev_err(dev, "Unable to parse or map IRQ\n"); 474 return -ENXIO; 475 } 476 477 error = devm_request_threaded_irq(dev, irq, NULL, cap11xx_thread_func, 478 IRQF_ONESHOT, dev_name(dev), priv); 479 if (error) 480 return error; 481 482 return 0; 483 } 484 485 static const struct of_device_id cap11xx_dt_ids[] = { 486 { .compatible = "microchip,cap1106", }, 487 { .compatible = "microchip,cap1126", }, 488 { .compatible = "microchip,cap1188", }, 489 {} 490 }; 491 MODULE_DEVICE_TABLE(of, cap11xx_dt_ids); 492 493 static const struct i2c_device_id cap11xx_i2c_ids[] = { 494 { "cap1106", CAP1106 }, 495 { "cap1126", CAP1126 }, 496 { "cap1188", CAP1188 }, 497 {} 498 }; 499 MODULE_DEVICE_TABLE(i2c, cap11xx_i2c_ids); 500 501 static struct i2c_driver cap11xx_i2c_driver = { 502 .driver = { 503 .name = "cap11xx", 504 .of_match_table = cap11xx_dt_ids, 505 }, 506 .id_table = cap11xx_i2c_ids, 507 .probe = cap11xx_i2c_probe, 508 }; 509 510 module_i2c_driver(cap11xx_i2c_driver); 511 512 MODULE_DESCRIPTION("Microchip CAP11XX driver"); 513 MODULE_AUTHOR("Daniel Mack <linux@zonque.org>"); 514 MODULE_LICENSE("GPL v2"); 515