1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2013 Capella Microsystems Inc. 4 * Author: Kevin Tsai <ktsai@capellamicro.com> 5 */ 6 7 #include <linux/acpi.h> 8 #include <linux/delay.h> 9 #include <linux/err.h> 10 #include <linux/i2c.h> 11 #include <linux/mutex.h> 12 #include <linux/module.h> 13 #include <linux/interrupt.h> 14 #include <linux/regulator/consumer.h> 15 #include <linux/iio/iio.h> 16 #include <linux/iio/sysfs.h> 17 #include <linux/iio/events.h> 18 #include <linux/init.h> 19 20 /* Registers Address */ 21 #define CM32181_REG_ADDR_CMD 0x00 22 #define CM32181_REG_ADDR_WH 0x01 23 #define CM32181_REG_ADDR_WL 0x02 24 #define CM32181_REG_ADDR_TEST 0x03 25 #define CM32181_REG_ADDR_ALS 0x04 26 #define CM32181_REG_ADDR_STATUS 0x06 27 #define CM32181_REG_ADDR_ID 0x07 28 29 /* Number of Configurable Registers */ 30 #define CM32181_CONF_REG_NUM 4 31 32 /* CMD register */ 33 #define CM32181_CMD_ALS_DISABLE BIT(0) 34 #define CM32181_CMD_ALS_INT_EN BIT(1) 35 #define CM32181_CMD_ALS_THRES_WINDOW BIT(2) 36 37 #define CM32181_CMD_ALS_PERS_SHIFT 4 38 #define CM32181_CMD_ALS_PERS_MASK (0x03 << CM32181_CMD_ALS_PERS_SHIFT) 39 #define CM32181_CMD_ALS_PERS_DEFAULT (0x01 << CM32181_CMD_ALS_PERS_SHIFT) 40 41 #define CM32181_CMD_ALS_IT_SHIFT 6 42 #define CM32181_CMD_ALS_IT_MASK (0x0F << CM32181_CMD_ALS_IT_SHIFT) 43 #define CM32181_CMD_ALS_IT_DEFAULT (0x00 << CM32181_CMD_ALS_IT_SHIFT) 44 45 #define CM32181_CMD_ALS_SM_SHIFT 11 46 #define CM32181_CMD_ALS_SM_MASK (0x03 << CM32181_CMD_ALS_SM_SHIFT) 47 #define CM32181_CMD_ALS_SM_DEFAULT (0x01 << CM32181_CMD_ALS_SM_SHIFT) 48 49 #define CM32181_LUX_PER_BIT 500 /* ALS_SM=01 IT=800ms */ 50 #define CM32181_LUX_PER_BIT_RESOLUTION 100000 51 #define CM32181_LUX_PER_BIT_BASE_IT 800000 /* Based on IT=800ms */ 52 #define CM32181_CALIBSCALE_DEFAULT 100000 53 #define CM32181_CALIBSCALE_RESOLUTION 100000 54 55 #define SMBUS_ALERT_RESPONSE_ADDRESS 0x0c 56 57 /* CPM0 Index 0: device-id (3218 or 32181), 1: Unknown, 2: init_regs_bitmap */ 58 #define CPM0_REGS_BITMAP 2 59 #define CPM0_HEADER_SIZE 3 60 61 /* CPM1 Index 0: lux_per_bit, 1: calibscale, 2: resolution (100000) */ 62 #define CPM1_LUX_PER_BIT 0 63 #define CPM1_CALIBSCALE 1 64 #define CPM1_SIZE 3 65 66 /* CM3218 Family */ 67 static const int cm3218_als_it_bits[] = { 0, 1, 2, 3 }; 68 static const int cm3218_als_it_values[] = { 100000, 200000, 400000, 800000 }; 69 70 /* CM32181 Family */ 71 static const int cm32181_als_it_bits[] = { 12, 8, 0, 1, 2, 3 }; 72 static const int cm32181_als_it_values[] = { 73 25000, 50000, 100000, 200000, 400000, 800000 74 }; 75 76 struct cm32181_chip { 77 struct i2c_client *client; 78 struct device *dev; 79 struct mutex lock; 80 u16 conf_regs[CM32181_CONF_REG_NUM]; 81 unsigned long init_regs_bitmap; 82 int calibscale; 83 int lux_per_bit; 84 int lux_per_bit_base_it; 85 int num_als_it; 86 const int *als_it_bits; 87 const int *als_it_values; 88 }; 89 90 static int cm32181_read_als_it(struct cm32181_chip *cm32181, int *val2); 91 92 #ifdef CONFIG_ACPI 93 /** 94 * cm32181_acpi_get_cpm() - Get CPM object from ACPI 95 * @dev: pointer of struct device. 96 * @obj_name: pointer of ACPI object name. 97 * @values: pointer of array for return elements. 98 * @count: maximum size of return array. 99 * 100 * Convert ACPI CPM table to array. 101 * 102 * Return: -ENODEV for fail. Otherwise is number of elements. 103 */ 104 static int cm32181_acpi_get_cpm(struct device *dev, char *obj_name, 105 u64 *values, int count) 106 { 107 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 108 union acpi_object *cpm, *elem; 109 acpi_handle handle; 110 acpi_status status; 111 int i; 112 113 handle = ACPI_HANDLE(dev); 114 if (!handle) 115 return -ENODEV; 116 117 status = acpi_evaluate_object(handle, obj_name, NULL, &buffer); 118 if (ACPI_FAILURE(status)) { 119 dev_err(dev, "object %s not found\n", obj_name); 120 return -ENODEV; 121 } 122 123 cpm = buffer.pointer; 124 if (cpm->package.count > count) 125 dev_warn(dev, "%s table contains %u values, only using first %d values\n", 126 obj_name, cpm->package.count, count); 127 128 count = min_t(int, cpm->package.count, count); 129 for (i = 0; i < count; i++) { 130 elem = &(cpm->package.elements[i]); 131 values[i] = elem->integer.value; 132 } 133 134 kfree(buffer.pointer); 135 136 return count; 137 } 138 139 static void cm32181_acpi_parse_cpm_tables(struct cm32181_chip *cm32181) 140 { 141 u64 vals[CPM0_HEADER_SIZE + CM32181_CONF_REG_NUM]; 142 struct device *dev = cm32181->dev; 143 int i, count; 144 145 count = cm32181_acpi_get_cpm(dev, "CPM0", vals, ARRAY_SIZE(vals)); 146 if (count <= CPM0_HEADER_SIZE) 147 return; 148 149 count -= CPM0_HEADER_SIZE; 150 151 cm32181->init_regs_bitmap = vals[CPM0_REGS_BITMAP]; 152 cm32181->init_regs_bitmap &= GENMASK(count - 1, 0); 153 for_each_set_bit(i, &cm32181->init_regs_bitmap, count) 154 cm32181->conf_regs[i] = vals[CPM0_HEADER_SIZE + i]; 155 156 count = cm32181_acpi_get_cpm(dev, "CPM1", vals, ARRAY_SIZE(vals)); 157 if (count != CPM1_SIZE) 158 return; 159 160 cm32181->lux_per_bit = vals[CPM1_LUX_PER_BIT]; 161 162 /* Check for uncalibrated devices */ 163 if (vals[CPM1_CALIBSCALE] == CM32181_CALIBSCALE_DEFAULT) 164 return; 165 166 cm32181->calibscale = vals[CPM1_CALIBSCALE]; 167 /* CPM1 lux_per_bit is for the current it value */ 168 cm32181_read_als_it(cm32181, &cm32181->lux_per_bit_base_it); 169 } 170 #else 171 static void cm32181_acpi_parse_cpm_tables(struct cm32181_chip *cm32181) 172 { 173 } 174 #endif /* CONFIG_ACPI */ 175 176 /** 177 * cm32181_reg_init() - Initialize CM32181 registers 178 * @cm32181: pointer of struct cm32181. 179 * 180 * Initialize CM32181 ambient light sensor register to default values. 181 * 182 * Return: 0 for success; otherwise for error code. 183 */ 184 static int cm32181_reg_init(struct cm32181_chip *cm32181) 185 { 186 struct i2c_client *client = cm32181->client; 187 int i; 188 s32 ret; 189 190 ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ID); 191 if (ret < 0) 192 return ret; 193 194 /* check device ID */ 195 switch (ret & 0xFF) { 196 case 0x18: /* CM3218 */ 197 cm32181->num_als_it = ARRAY_SIZE(cm3218_als_it_bits); 198 cm32181->als_it_bits = cm3218_als_it_bits; 199 cm32181->als_it_values = cm3218_als_it_values; 200 break; 201 case 0x81: /* CM32181 */ 202 case 0x82: /* CM32182, fully compat. with CM32181 */ 203 cm32181->num_als_it = ARRAY_SIZE(cm32181_als_it_bits); 204 cm32181->als_it_bits = cm32181_als_it_bits; 205 cm32181->als_it_values = cm32181_als_it_values; 206 break; 207 default: 208 return -ENODEV; 209 } 210 211 /* Default Values */ 212 cm32181->conf_regs[CM32181_REG_ADDR_CMD] = 213 CM32181_CMD_ALS_IT_DEFAULT | CM32181_CMD_ALS_SM_DEFAULT; 214 cm32181->init_regs_bitmap = BIT(CM32181_REG_ADDR_CMD); 215 cm32181->calibscale = CM32181_CALIBSCALE_DEFAULT; 216 cm32181->lux_per_bit = CM32181_LUX_PER_BIT; 217 cm32181->lux_per_bit_base_it = CM32181_LUX_PER_BIT_BASE_IT; 218 219 cm32181_acpi_parse_cpm_tables(cm32181); 220 221 /* Initialize registers*/ 222 for_each_set_bit(i, &cm32181->init_regs_bitmap, CM32181_CONF_REG_NUM) { 223 ret = i2c_smbus_write_word_data(client, i, 224 cm32181->conf_regs[i]); 225 if (ret < 0) 226 return ret; 227 } 228 229 return 0; 230 } 231 232 /** 233 * cm32181_read_als_it() - Get sensor integration time (ms) 234 * @cm32181: pointer of struct cm32181 235 * @val2: pointer of int to load the als_it value. 236 * 237 * Report the current integration time in milliseconds. 238 * 239 * Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL. 240 */ 241 static int cm32181_read_als_it(struct cm32181_chip *cm32181, int *val2) 242 { 243 u16 als_it; 244 int i; 245 246 als_it = cm32181->conf_regs[CM32181_REG_ADDR_CMD]; 247 als_it &= CM32181_CMD_ALS_IT_MASK; 248 als_it >>= CM32181_CMD_ALS_IT_SHIFT; 249 for (i = 0; i < cm32181->num_als_it; i++) { 250 if (als_it == cm32181->als_it_bits[i]) { 251 *val2 = cm32181->als_it_values[i]; 252 return IIO_VAL_INT_PLUS_MICRO; 253 } 254 } 255 256 return -EINVAL; 257 } 258 259 /** 260 * cm32181_write_als_it() - Write sensor integration time 261 * @cm32181: pointer of struct cm32181. 262 * @val: integration time by millisecond. 263 * 264 * Convert integration time (ms) to sensor value. 265 * 266 * Return: i2c_smbus_write_word_data command return value. 267 */ 268 static int cm32181_write_als_it(struct cm32181_chip *cm32181, int val) 269 { 270 struct i2c_client *client = cm32181->client; 271 u16 als_it; 272 int ret, i, n; 273 274 n = cm32181->num_als_it; 275 for (i = 0; i < n; i++) 276 if (val <= cm32181->als_it_values[i]) 277 break; 278 if (i >= n) 279 i = n - 1; 280 281 als_it = cm32181->als_it_bits[i]; 282 als_it <<= CM32181_CMD_ALS_IT_SHIFT; 283 284 mutex_lock(&cm32181->lock); 285 cm32181->conf_regs[CM32181_REG_ADDR_CMD] &= 286 ~CM32181_CMD_ALS_IT_MASK; 287 cm32181->conf_regs[CM32181_REG_ADDR_CMD] |= 288 als_it; 289 ret = i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD, 290 cm32181->conf_regs[CM32181_REG_ADDR_CMD]); 291 mutex_unlock(&cm32181->lock); 292 293 return ret; 294 } 295 296 /** 297 * cm32181_get_lux() - report current lux value 298 * @cm32181: pointer of struct cm32181. 299 * 300 * Convert sensor raw data to lux. It depends on integration 301 * time and calibscale variable. 302 * 303 * Return: Positive value is lux, otherwise is error code. 304 */ 305 static int cm32181_get_lux(struct cm32181_chip *cm32181) 306 { 307 struct i2c_client *client = cm32181->client; 308 int ret; 309 int als_it; 310 u64 lux; 311 312 ret = cm32181_read_als_it(cm32181, &als_it); 313 if (ret < 0) 314 return -EINVAL; 315 316 lux = cm32181->lux_per_bit; 317 lux *= cm32181->lux_per_bit_base_it; 318 lux = div_u64(lux, als_it); 319 320 ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ALS); 321 if (ret < 0) 322 return ret; 323 324 lux *= ret; 325 lux *= cm32181->calibscale; 326 lux = div_u64(lux, CM32181_CALIBSCALE_RESOLUTION); 327 lux = div_u64(lux, CM32181_LUX_PER_BIT_RESOLUTION); 328 329 if (lux > 0xFFFF) 330 lux = 0xFFFF; 331 332 return lux; 333 } 334 335 static int cm32181_read_raw(struct iio_dev *indio_dev, 336 struct iio_chan_spec const *chan, 337 int *val, int *val2, long mask) 338 { 339 struct cm32181_chip *cm32181 = iio_priv(indio_dev); 340 int ret; 341 342 switch (mask) { 343 case IIO_CHAN_INFO_PROCESSED: 344 ret = cm32181_get_lux(cm32181); 345 if (ret < 0) 346 return ret; 347 *val = ret; 348 return IIO_VAL_INT; 349 case IIO_CHAN_INFO_CALIBSCALE: 350 *val = cm32181->calibscale; 351 return IIO_VAL_INT; 352 case IIO_CHAN_INFO_INT_TIME: 353 *val = 0; 354 ret = cm32181_read_als_it(cm32181, val2); 355 return ret; 356 } 357 358 return -EINVAL; 359 } 360 361 static int cm32181_write_raw(struct iio_dev *indio_dev, 362 struct iio_chan_spec const *chan, 363 int val, int val2, long mask) 364 { 365 struct cm32181_chip *cm32181 = iio_priv(indio_dev); 366 int ret; 367 368 switch (mask) { 369 case IIO_CHAN_INFO_CALIBSCALE: 370 cm32181->calibscale = val; 371 return 0; 372 case IIO_CHAN_INFO_INT_TIME: 373 ret = cm32181_write_als_it(cm32181, val2); 374 return ret; 375 } 376 377 return -EINVAL; 378 } 379 380 /** 381 * cm32181_get_it_available() - Get available ALS IT value 382 * @dev: pointer of struct device. 383 * @attr: pointer of struct device_attribute. 384 * @buf: pointer of return string buffer. 385 * 386 * Display the available integration time values by millisecond. 387 * 388 * Return: string length. 389 */ 390 static ssize_t cm32181_get_it_available(struct device *dev, 391 struct device_attribute *attr, char *buf) 392 { 393 struct cm32181_chip *cm32181 = iio_priv(dev_to_iio_dev(dev)); 394 int i, n, len; 395 396 n = cm32181->num_als_it; 397 for (i = 0, len = 0; i < n; i++) 398 len += sprintf(buf + len, "0.%06u ", cm32181->als_it_values[i]); 399 return len + sprintf(buf + len, "\n"); 400 } 401 402 static const struct iio_chan_spec cm32181_channels[] = { 403 { 404 .type = IIO_LIGHT, 405 .info_mask_separate = 406 BIT(IIO_CHAN_INFO_PROCESSED) | 407 BIT(IIO_CHAN_INFO_CALIBSCALE) | 408 BIT(IIO_CHAN_INFO_INT_TIME), 409 } 410 }; 411 412 static IIO_DEVICE_ATTR(in_illuminance_integration_time_available, 413 S_IRUGO, cm32181_get_it_available, NULL, 0); 414 415 static struct attribute *cm32181_attributes[] = { 416 &iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr, 417 NULL, 418 }; 419 420 static const struct attribute_group cm32181_attribute_group = { 421 .attrs = cm32181_attributes 422 }; 423 424 static const struct iio_info cm32181_info = { 425 .read_raw = &cm32181_read_raw, 426 .write_raw = &cm32181_write_raw, 427 .attrs = &cm32181_attribute_group, 428 }; 429 430 static void cm32181_unregister_dummy_client(void *data) 431 { 432 struct i2c_client *client = data; 433 434 /* Unregister the dummy client */ 435 i2c_unregister_device(client); 436 } 437 438 static int cm32181_probe(struct i2c_client *client) 439 { 440 struct device *dev = &client->dev; 441 struct cm32181_chip *cm32181; 442 struct iio_dev *indio_dev; 443 int ret; 444 445 indio_dev = devm_iio_device_alloc(dev, sizeof(*cm32181)); 446 if (!indio_dev) 447 return -ENOMEM; 448 449 i2c_set_clientdata(client, indio_dev); 450 451 /* 452 * Some ACPI systems list 2 I2C resources for the CM3218 sensor, the 453 * SMBus Alert Response Address (ARA, 0x0c) and the actual I2C address. 454 * Detect this and take the following step to deal with it: 455 * 1. When a SMBus Alert capable sensor has an Alert asserted, it will 456 * not respond on its actual I2C address. Read a byte from the ARA 457 * to clear any pending Alerts. 458 * 2. Create a "dummy" client for the actual I2C address and 459 * use that client to communicate with the sensor. 460 */ 461 if (ACPI_HANDLE(dev) && client->addr == SMBUS_ALERT_RESPONSE_ADDRESS) { 462 struct i2c_board_info board_info = { .type = "dummy" }; 463 464 i2c_smbus_read_byte(client); 465 466 client = i2c_acpi_new_device(dev, 1, &board_info); 467 if (IS_ERR(client)) 468 return PTR_ERR(client); 469 470 ret = devm_add_action_or_reset(dev, cm32181_unregister_dummy_client, client); 471 if (ret) 472 return ret; 473 } 474 475 cm32181 = iio_priv(indio_dev); 476 cm32181->client = client; 477 cm32181->dev = dev; 478 479 mutex_init(&cm32181->lock); 480 indio_dev->channels = cm32181_channels; 481 indio_dev->num_channels = ARRAY_SIZE(cm32181_channels); 482 indio_dev->info = &cm32181_info; 483 indio_dev->name = dev_name(dev); 484 indio_dev->modes = INDIO_DIRECT_MODE; 485 486 ret = cm32181_reg_init(cm32181); 487 if (ret) { 488 dev_err(dev, "%s: register init failed\n", __func__); 489 return ret; 490 } 491 492 ret = devm_iio_device_register(dev, indio_dev); 493 if (ret) { 494 dev_err(dev, "%s: register device failed\n", __func__); 495 return ret; 496 } 497 498 return 0; 499 } 500 501 static int cm32181_suspend(struct device *dev) 502 { 503 struct cm32181_chip *cm32181 = iio_priv(dev_get_drvdata(dev)); 504 struct i2c_client *client = cm32181->client; 505 506 return i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD, 507 CM32181_CMD_ALS_DISABLE); 508 } 509 510 static int cm32181_resume(struct device *dev) 511 { 512 struct cm32181_chip *cm32181 = iio_priv(dev_get_drvdata(dev)); 513 struct i2c_client *client = cm32181->client; 514 515 return i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD, 516 cm32181->conf_regs[CM32181_REG_ADDR_CMD]); 517 } 518 519 static DEFINE_SIMPLE_DEV_PM_OPS(cm32181_pm_ops, cm32181_suspend, cm32181_resume); 520 521 static const struct of_device_id cm32181_of_match[] = { 522 { .compatible = "capella,cm3218" }, 523 { .compatible = "capella,cm32181" }, 524 { } 525 }; 526 MODULE_DEVICE_TABLE(of, cm32181_of_match); 527 528 #ifdef CONFIG_ACPI 529 static const struct acpi_device_id cm32181_acpi_match[] = { 530 { "CPLM3218", 0 }, 531 { } 532 }; 533 MODULE_DEVICE_TABLE(acpi, cm32181_acpi_match); 534 #endif 535 536 static struct i2c_driver cm32181_driver = { 537 .driver = { 538 .name = "cm32181", 539 .acpi_match_table = ACPI_PTR(cm32181_acpi_match), 540 .of_match_table = cm32181_of_match, 541 .pm = pm_sleep_ptr(&cm32181_pm_ops), 542 }, 543 .probe = cm32181_probe, 544 }; 545 546 module_i2c_driver(cm32181_driver); 547 548 MODULE_AUTHOR("Kevin Tsai <ktsai@capellamicro.com>"); 549 MODULE_DESCRIPTION("CM32181 ambient light sensor driver"); 550 MODULE_LICENSE("GPL"); 551