1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Input driver for Microchip CAP11xx based capacitive touch sensors 4 * 5 * (c) 2014 Daniel Mack <linux@zonque.org> 6 */ 7 8 #include <linux/kernel.h> 9 #include <linux/module.h> 10 #include <linux/interrupt.h> 11 #include <linux/input.h> 12 #include <linux/leds.h> 13 #include <linux/of_irq.h> 14 #include <linux/regmap.h> 15 #include <linux/i2c.h> 16 #include <linux/gpio/consumer.h> 17 18 #define CAP11XX_REG_MAIN_CONTROL 0x00 19 #define CAP11XX_REG_MAIN_CONTROL_GAIN_SHIFT (6) 20 #define CAP11XX_REG_MAIN_CONTROL_GAIN_MASK (0xc0) 21 #define CAP11XX_REG_MAIN_CONTROL_DLSEEP BIT(4) 22 #define CAP11XX_REG_GENERAL_STATUS 0x02 23 #define CAP11XX_REG_SENSOR_INPUT 0x03 24 #define CAP11XX_REG_NOISE_FLAG_STATUS 0x0a 25 #define CAP11XX_REG_SENOR_DELTA(X) (0x10 + (X)) 26 #define CAP11XX_REG_SENSITIVITY_CONTROL 0x1f 27 #define CAP11XX_REG_CONFIG 0x20 28 #define CAP11XX_REG_SENSOR_ENABLE 0x21 29 #define CAP11XX_REG_SENSOR_CONFIG 0x22 30 #define CAP11XX_REG_SENSOR_CONFIG2 0x23 31 #define CAP11XX_REG_SAMPLING_CONFIG 0x24 32 #define CAP11XX_REG_CALIBRATION 0x26 33 #define CAP11XX_REG_INT_ENABLE 0x27 34 #define CAP11XX_REG_REPEAT_RATE 0x28 35 #define CAP11XX_REG_MT_CONFIG 0x2a 36 #define CAP11XX_REG_MT_PATTERN_CONFIG 0x2b 37 #define CAP11XX_REG_MT_PATTERN 0x2d 38 #define CAP11XX_REG_RECALIB_CONFIG 0x2f 39 #define CAP11XX_REG_SENSOR_THRESH(X) (0x30 + (X)) 40 #define CAP11XX_REG_SENSOR_NOISE_THRESH 0x38 41 #define CAP11XX_REG_STANDBY_CHANNEL 0x40 42 #define CAP11XX_REG_STANDBY_CONFIG 0x41 43 #define CAP11XX_REG_STANDBY_SENSITIVITY 0x42 44 #define CAP11XX_REG_STANDBY_THRESH 0x43 45 #define CAP11XX_REG_CONFIG2 0x44 46 #define CAP11XX_REG_CONFIG2_ALT_POL BIT(6) 47 #define CAP11XX_REG_SENSOR_BASE_CNT(X) (0x50 + (X)) 48 #define CAP11XX_REG_LED_POLARITY 0x73 49 #define CAP11XX_REG_LED_OUTPUT_CONTROL 0x74 50 51 #define CAP11XX_REG_LED_DUTY_CYCLE_1 0x90 52 #define CAP11XX_REG_LED_DUTY_CYCLE_2 0x91 53 #define CAP11XX_REG_LED_DUTY_CYCLE_3 0x92 54 #define CAP11XX_REG_LED_DUTY_CYCLE_4 0x93 55 56 #define CAP11XX_REG_LED_DUTY_MIN_MASK (0x0f) 57 #define CAP11XX_REG_LED_DUTY_MIN_MASK_SHIFT (0) 58 #define CAP11XX_REG_LED_DUTY_MAX_MASK (0xf0) 59 #define CAP11XX_REG_LED_DUTY_MAX_MASK_SHIFT (4) 60 #define CAP11XX_REG_LED_DUTY_MAX_VALUE (15) 61 62 #define CAP11XX_REG_SENSOR_CALIB (0xb1 + (X)) 63 #define CAP11XX_REG_SENSOR_CALIB_LSB1 0xb9 64 #define CAP11XX_REG_SENSOR_CALIB_LSB2 0xba 65 #define CAP11XX_REG_PRODUCT_ID 0xfd 66 #define CAP11XX_REG_MANUFACTURER_ID 0xfe 67 #define CAP11XX_REG_REVISION 0xff 68 69 #define CAP11XX_MANUFACTURER_ID 0x5d 70 71 #ifdef CONFIG_LEDS_CLASS 72 struct cap11xx_led { 73 struct cap11xx_priv *priv; 74 struct led_classdev cdev; 75 u32 reg; 76 }; 77 #endif 78 79 struct cap11xx_priv { 80 struct regmap *regmap; 81 struct input_dev *idev; 82 83 struct cap11xx_led *leds; 84 int num_leds; 85 86 /* config */ 87 u32 keycodes[]; 88 }; 89 90 struct cap11xx_hw_model { 91 u8 product_id; 92 unsigned int num_channels; 93 unsigned int num_leds; 94 }; 95 96 enum { 97 CAP1106, 98 CAP1126, 99 CAP1188, 100 }; 101 102 static const struct cap11xx_hw_model cap11xx_devices[] = { 103 [CAP1106] = { .product_id = 0x55, .num_channels = 6, .num_leds = 0 }, 104 [CAP1126] = { .product_id = 0x53, .num_channels = 6, .num_leds = 2 }, 105 [CAP1188] = { .product_id = 0x50, .num_channels = 8, .num_leds = 8 }, 106 }; 107 108 static const struct reg_default cap11xx_reg_defaults[] = { 109 { CAP11XX_REG_MAIN_CONTROL, 0x00 }, 110 { CAP11XX_REG_GENERAL_STATUS, 0x00 }, 111 { CAP11XX_REG_SENSOR_INPUT, 0x00 }, 112 { CAP11XX_REG_NOISE_FLAG_STATUS, 0x00 }, 113 { CAP11XX_REG_SENSITIVITY_CONTROL, 0x2f }, 114 { CAP11XX_REG_CONFIG, 0x20 }, 115 { CAP11XX_REG_SENSOR_ENABLE, 0x3f }, 116 { CAP11XX_REG_SENSOR_CONFIG, 0xa4 }, 117 { CAP11XX_REG_SENSOR_CONFIG2, 0x07 }, 118 { CAP11XX_REG_SAMPLING_CONFIG, 0x39 }, 119 { CAP11XX_REG_CALIBRATION, 0x00 }, 120 { CAP11XX_REG_INT_ENABLE, 0x3f }, 121 { CAP11XX_REG_REPEAT_RATE, 0x3f }, 122 { CAP11XX_REG_MT_CONFIG, 0x80 }, 123 { CAP11XX_REG_MT_PATTERN_CONFIG, 0x00 }, 124 { CAP11XX_REG_MT_PATTERN, 0x3f }, 125 { CAP11XX_REG_RECALIB_CONFIG, 0x8a }, 126 { CAP11XX_REG_SENSOR_THRESH(0), 0x40 }, 127 { CAP11XX_REG_SENSOR_THRESH(1), 0x40 }, 128 { CAP11XX_REG_SENSOR_THRESH(2), 0x40 }, 129 { CAP11XX_REG_SENSOR_THRESH(3), 0x40 }, 130 { CAP11XX_REG_SENSOR_THRESH(4), 0x40 }, 131 { CAP11XX_REG_SENSOR_THRESH(5), 0x40 }, 132 { CAP11XX_REG_SENSOR_NOISE_THRESH, 0x01 }, 133 { CAP11XX_REG_STANDBY_CHANNEL, 0x00 }, 134 { CAP11XX_REG_STANDBY_CONFIG, 0x39 }, 135 { CAP11XX_REG_STANDBY_SENSITIVITY, 0x02 }, 136 { CAP11XX_REG_STANDBY_THRESH, 0x40 }, 137 { CAP11XX_REG_CONFIG2, 0x40 }, 138 { CAP11XX_REG_LED_POLARITY, 0x00 }, 139 { CAP11XX_REG_SENSOR_CALIB_LSB1, 0x00 }, 140 { CAP11XX_REG_SENSOR_CALIB_LSB2, 0x00 }, 141 }; 142 143 static bool cap11xx_volatile_reg(struct device *dev, unsigned int reg) 144 { 145 switch (reg) { 146 case CAP11XX_REG_MAIN_CONTROL: 147 case CAP11XX_REG_SENSOR_INPUT: 148 case CAP11XX_REG_SENOR_DELTA(0): 149 case CAP11XX_REG_SENOR_DELTA(1): 150 case CAP11XX_REG_SENOR_DELTA(2): 151 case CAP11XX_REG_SENOR_DELTA(3): 152 case CAP11XX_REG_SENOR_DELTA(4): 153 case CAP11XX_REG_SENOR_DELTA(5): 154 case CAP11XX_REG_PRODUCT_ID: 155 case CAP11XX_REG_MANUFACTURER_ID: 156 case CAP11XX_REG_REVISION: 157 return true; 158 } 159 160 return false; 161 } 162 163 static const struct regmap_config cap11xx_regmap_config = { 164 .reg_bits = 8, 165 .val_bits = 8, 166 167 .max_register = CAP11XX_REG_REVISION, 168 .reg_defaults = cap11xx_reg_defaults, 169 170 .num_reg_defaults = ARRAY_SIZE(cap11xx_reg_defaults), 171 .cache_type = REGCACHE_RBTREE, 172 .volatile_reg = cap11xx_volatile_reg, 173 }; 174 175 static irqreturn_t cap11xx_thread_func(int irq_num, void *data) 176 { 177 struct cap11xx_priv *priv = data; 178 unsigned int status; 179 int ret, i; 180 181 /* 182 * Deassert interrupt. This needs to be done before reading the status 183 * registers, which will not carry valid values otherwise. 184 */ 185 ret = regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL, 1, 0); 186 if (ret < 0) 187 goto out; 188 189 ret = regmap_read(priv->regmap, CAP11XX_REG_SENSOR_INPUT, &status); 190 if (ret < 0) 191 goto out; 192 193 for (i = 0; i < priv->idev->keycodemax; i++) 194 input_report_key(priv->idev, priv->keycodes[i], 195 status & (1 << i)); 196 197 input_sync(priv->idev); 198 199 out: 200 return IRQ_HANDLED; 201 } 202 203 static int cap11xx_set_sleep(struct cap11xx_priv *priv, bool sleep) 204 { 205 /* 206 * DLSEEP mode will turn off all LEDS, prevent this 207 */ 208 if (IS_ENABLED(CONFIG_LEDS_CLASS) && priv->num_leds) 209 return 0; 210 211 return regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL, 212 CAP11XX_REG_MAIN_CONTROL_DLSEEP, 213 sleep ? CAP11XX_REG_MAIN_CONTROL_DLSEEP : 0); 214 } 215 216 static int cap11xx_input_open(struct input_dev *idev) 217 { 218 struct cap11xx_priv *priv = input_get_drvdata(idev); 219 220 return cap11xx_set_sleep(priv, false); 221 } 222 223 static void cap11xx_input_close(struct input_dev *idev) 224 { 225 struct cap11xx_priv *priv = input_get_drvdata(idev); 226 227 cap11xx_set_sleep(priv, true); 228 } 229 230 #ifdef CONFIG_LEDS_CLASS 231 static int cap11xx_led_set(struct led_classdev *cdev, 232 enum led_brightness value) 233 { 234 struct cap11xx_led *led = container_of(cdev, struct cap11xx_led, cdev); 235 struct cap11xx_priv *priv = led->priv; 236 237 /* 238 * All LEDs share the same duty cycle as this is a HW 239 * limitation. Brightness levels per LED are either 240 * 0 (OFF) and 1 (ON). 241 */ 242 return regmap_update_bits(priv->regmap, 243 CAP11XX_REG_LED_OUTPUT_CONTROL, 244 BIT(led->reg), 245 value ? BIT(led->reg) : 0); 246 } 247 248 static int cap11xx_init_leds(struct device *dev, 249 struct cap11xx_priv *priv, int num_leds) 250 { 251 struct device_node *node = dev->of_node, *child; 252 struct cap11xx_led *led; 253 int cnt = of_get_child_count(node); 254 int error; 255 256 if (!num_leds || !cnt) 257 return 0; 258 259 if (cnt > num_leds) 260 return -EINVAL; 261 262 led = devm_kcalloc(dev, cnt, sizeof(struct cap11xx_led), GFP_KERNEL); 263 if (!led) 264 return -ENOMEM; 265 266 priv->leds = led; 267 268 error = regmap_update_bits(priv->regmap, 269 CAP11XX_REG_LED_OUTPUT_CONTROL, 0xff, 0); 270 if (error) 271 return error; 272 273 error = regmap_update_bits(priv->regmap, CAP11XX_REG_LED_DUTY_CYCLE_4, 274 CAP11XX_REG_LED_DUTY_MAX_MASK, 275 CAP11XX_REG_LED_DUTY_MAX_VALUE << 276 CAP11XX_REG_LED_DUTY_MAX_MASK_SHIFT); 277 if (error) 278 return error; 279 280 for_each_child_of_node(node, child) { 281 u32 reg; 282 283 led->cdev.name = 284 of_get_property(child, "label", NULL) ? : child->name; 285 led->cdev.default_trigger = 286 of_get_property(child, "linux,default-trigger", NULL); 287 led->cdev.flags = 0; 288 led->cdev.brightness_set_blocking = cap11xx_led_set; 289 led->cdev.max_brightness = 1; 290 led->cdev.brightness = LED_OFF; 291 292 error = of_property_read_u32(child, "reg", ®); 293 if (error != 0 || reg >= num_leds) { 294 of_node_put(child); 295 return -EINVAL; 296 } 297 298 led->reg = reg; 299 led->priv = priv; 300 301 error = devm_led_classdev_register(dev, &led->cdev); 302 if (error) { 303 of_node_put(child); 304 return error; 305 } 306 307 priv->num_leds++; 308 led++; 309 } 310 311 return 0; 312 } 313 #else 314 static int cap11xx_init_leds(struct device *dev, 315 struct cap11xx_priv *priv, int num_leds) 316 { 317 return 0; 318 } 319 #endif 320 321 static int cap11xx_i2c_probe(struct i2c_client *i2c_client, 322 const struct i2c_device_id *id) 323 { 324 struct device *dev = &i2c_client->dev; 325 struct cap11xx_priv *priv; 326 struct device_node *node; 327 const struct cap11xx_hw_model *cap; 328 int i, error, irq, gain = 0; 329 unsigned int val, rev; 330 u32 gain32; 331 332 if (id->driver_data >= ARRAY_SIZE(cap11xx_devices)) { 333 dev_err(dev, "Invalid device ID %lu\n", id->driver_data); 334 return -EINVAL; 335 } 336 337 cap = &cap11xx_devices[id->driver_data]; 338 if (!cap || !cap->num_channels) { 339 dev_err(dev, "Invalid device configuration\n"); 340 return -EINVAL; 341 } 342 343 priv = devm_kzalloc(dev, 344 struct_size(priv, keycodes, cap->num_channels), 345 GFP_KERNEL); 346 if (!priv) 347 return -ENOMEM; 348 349 priv->regmap = devm_regmap_init_i2c(i2c_client, &cap11xx_regmap_config); 350 if (IS_ERR(priv->regmap)) 351 return PTR_ERR(priv->regmap); 352 353 error = regmap_read(priv->regmap, CAP11XX_REG_PRODUCT_ID, &val); 354 if (error) 355 return error; 356 357 if (val != cap->product_id) { 358 dev_err(dev, "Product ID: Got 0x%02x, expected 0x%02x\n", 359 val, cap->product_id); 360 return -ENXIO; 361 } 362 363 error = regmap_read(priv->regmap, CAP11XX_REG_MANUFACTURER_ID, &val); 364 if (error) 365 return error; 366 367 if (val != CAP11XX_MANUFACTURER_ID) { 368 dev_err(dev, "Manufacturer ID: Got 0x%02x, expected 0x%02x\n", 369 val, CAP11XX_MANUFACTURER_ID); 370 return -ENXIO; 371 } 372 373 error = regmap_read(priv->regmap, CAP11XX_REG_REVISION, &rev); 374 if (error < 0) 375 return error; 376 377 dev_info(dev, "CAP11XX detected, revision 0x%02x\n", rev); 378 node = dev->of_node; 379 380 if (!of_property_read_u32(node, "microchip,sensor-gain", &gain32)) { 381 if (is_power_of_2(gain32) && gain32 <= 8) 382 gain = ilog2(gain32); 383 else 384 dev_err(dev, "Invalid sensor-gain value %d\n", gain32); 385 } 386 387 if (of_property_read_bool(node, "microchip,irq-active-high")) { 388 error = regmap_update_bits(priv->regmap, CAP11XX_REG_CONFIG2, 389 CAP11XX_REG_CONFIG2_ALT_POL, 0); 390 if (error) 391 return error; 392 } 393 394 /* Provide some useful defaults */ 395 for (i = 0; i < cap->num_channels; i++) 396 priv->keycodes[i] = KEY_A + i; 397 398 of_property_read_u32_array(node, "linux,keycodes", 399 priv->keycodes, cap->num_channels); 400 401 error = regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL, 402 CAP11XX_REG_MAIN_CONTROL_GAIN_MASK, 403 gain << CAP11XX_REG_MAIN_CONTROL_GAIN_SHIFT); 404 if (error) 405 return error; 406 407 /* Disable autorepeat. The Linux input system has its own handling. */ 408 error = regmap_write(priv->regmap, CAP11XX_REG_REPEAT_RATE, 0); 409 if (error) 410 return error; 411 412 priv->idev = devm_input_allocate_device(dev); 413 if (!priv->idev) 414 return -ENOMEM; 415 416 priv->idev->name = "CAP11XX capacitive touch sensor"; 417 priv->idev->id.bustype = BUS_I2C; 418 priv->idev->evbit[0] = BIT_MASK(EV_KEY); 419 420 if (of_property_read_bool(node, "autorepeat")) 421 __set_bit(EV_REP, priv->idev->evbit); 422 423 for (i = 0; i < cap->num_channels; i++) 424 __set_bit(priv->keycodes[i], priv->idev->keybit); 425 426 __clear_bit(KEY_RESERVED, priv->idev->keybit); 427 428 priv->idev->keycode = priv->keycodes; 429 priv->idev->keycodesize = sizeof(priv->keycodes[0]); 430 priv->idev->keycodemax = cap->num_channels; 431 432 priv->idev->id.vendor = CAP11XX_MANUFACTURER_ID; 433 priv->idev->id.product = cap->product_id; 434 priv->idev->id.version = rev; 435 436 priv->idev->open = cap11xx_input_open; 437 priv->idev->close = cap11xx_input_close; 438 439 error = cap11xx_init_leds(dev, priv, cap->num_leds); 440 if (error) 441 return error; 442 443 input_set_drvdata(priv->idev, priv); 444 445 /* 446 * Put the device in deep sleep mode for now. 447 * ->open() will bring it back once the it is actually needed. 448 */ 449 cap11xx_set_sleep(priv, true); 450 451 error = input_register_device(priv->idev); 452 if (error) 453 return error; 454 455 irq = irq_of_parse_and_map(node, 0); 456 if (!irq) { 457 dev_err(dev, "Unable to parse or map IRQ\n"); 458 return -ENXIO; 459 } 460 461 error = devm_request_threaded_irq(dev, irq, NULL, cap11xx_thread_func, 462 IRQF_ONESHOT, dev_name(dev), priv); 463 if (error) 464 return error; 465 466 return 0; 467 } 468 469 static const struct of_device_id cap11xx_dt_ids[] = { 470 { .compatible = "microchip,cap1106", }, 471 { .compatible = "microchip,cap1126", }, 472 { .compatible = "microchip,cap1188", }, 473 {} 474 }; 475 MODULE_DEVICE_TABLE(of, cap11xx_dt_ids); 476 477 static const struct i2c_device_id cap11xx_i2c_ids[] = { 478 { "cap1106", CAP1106 }, 479 { "cap1126", CAP1126 }, 480 { "cap1188", CAP1188 }, 481 {} 482 }; 483 MODULE_DEVICE_TABLE(i2c, cap11xx_i2c_ids); 484 485 static struct i2c_driver cap11xx_i2c_driver = { 486 .driver = { 487 .name = "cap11xx", 488 .of_match_table = cap11xx_dt_ids, 489 }, 490 .id_table = cap11xx_i2c_ids, 491 .probe = cap11xx_i2c_probe, 492 }; 493 494 module_i2c_driver(cap11xx_i2c_driver); 495 496 MODULE_DESCRIPTION("Microchip CAP11XX driver"); 497 MODULE_AUTHOR("Daniel Mack <linux@zonque.org>"); 498 MODULE_LICENSE("GPL v2"); 499