drivers/input/keyboard/cap11xx.c

   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", &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");