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/mod_devicetable.h> 14 #include <linux/interrupt.h> 15 #include <linux/regulator/consumer.h> 16 #include <linux/iio/iio.h> 17 #include <linux/iio/sysfs.h> 18 #include <linux/iio/events.h> 19 #include <linux/init.h> 20 21 /* Registers Address */ 22 #define CM32181_REG_ADDR_CMD 0x00 23 #define CM32181_REG_ADDR_WH 0x01 24 #define CM32181_REG_ADDR_WL 0x02 25 #define CM32181_REG_ADDR_TEST 0x03 26 #define CM32181_REG_ADDR_ALS 0x04 27 #define CM32181_REG_ADDR_STATUS 0x06 28 #define CM32181_REG_ADDR_ID 0x07 29 30 /* Number of Configurable Registers */ 31 #define CM32181_CONF_REG_NUM 4 32 33 /* CMD register */ 34 #define CM32181_CMD_ALS_DISABLE BIT(0) 35 #define CM32181_CMD_ALS_INT_EN BIT(1) 36 #define CM32181_CMD_ALS_THRES_WINDOW BIT(2) 37 38 #define CM32181_CMD_ALS_PERS_SHIFT 4 39 #define CM32181_CMD_ALS_PERS_MASK (0x03 << CM32181_CMD_ALS_PERS_SHIFT) 40 #define CM32181_CMD_ALS_PERS_DEFAULT (0x01 << CM32181_CMD_ALS_PERS_SHIFT) 41 42 #define CM32181_CMD_ALS_IT_SHIFT 6 43 #define CM32181_CMD_ALS_IT_MASK (0x0F << CM32181_CMD_ALS_IT_SHIFT) 44 #define CM32181_CMD_ALS_IT_DEFAULT (0x00 << CM32181_CMD_ALS_IT_SHIFT) 45 46 #define CM32181_CMD_ALS_SM_SHIFT 11 47 #define CM32181_CMD_ALS_SM_MASK (0x03 << CM32181_CMD_ALS_SM_SHIFT) 48 #define CM32181_CMD_ALS_SM_DEFAULT (0x01 << CM32181_CMD_ALS_SM_SHIFT) 49 50 #define CM32181_LUX_PER_BIT 500 /* ALS_SM=01 IT=800ms */ 51 #define CM32181_LUX_PER_BIT_RESOLUTION 100000 52 #define CM32181_LUX_PER_BIT_BASE_IT 800000 /* Based on IT=800ms */ 53 #define CM32181_CALIBSCALE_DEFAULT 100000 54 #define CM32181_CALIBSCALE_RESOLUTION 100000 55 56 #define SMBUS_ALERT_RESPONSE_ADDRESS 0x0c 57 58 /* CPM0 Index 0: device-id (3218 or 32181), 1: Unknown, 2: init_regs_bitmap */ 59 #define CPM0_REGS_BITMAP 2 60 #define CPM0_HEADER_SIZE 3 61 62 /* CPM1 Index 0: lux_per_bit, 1: calibscale, 2: resolution (100000) */ 63 #define CPM1_LUX_PER_BIT 0 64 #define CPM1_CALIBSCALE 1 65 #define CPM1_SIZE 3 66 67 /* CM3218 Family */ 68 static const int cm3218_als_it_bits[] = { 0, 1, 2, 3 }; 69 static const int cm3218_als_it_values[] = { 100000, 200000, 400000, 800000 }; 70 71 /* CM32181 Family */ 72 static const int cm32181_als_it_bits[] = { 12, 8, 0, 1, 2, 3 }; 73 static const int cm32181_als_it_values[] = { 74 25000, 50000, 100000, 200000, 400000, 800000 75 }; 76 77 struct cm32181_chip { 78 struct i2c_client *client; 79 struct device *dev; 80 struct mutex lock; 81 u16 conf_regs[CM32181_CONF_REG_NUM]; 82 unsigned long init_regs_bitmap; 83 int calibscale; 84 int lux_per_bit; 85 int lux_per_bit_base_it; 86 int num_als_it; 87 const int *als_it_bits; 88 const int *als_it_values; 89 }; 90 91 static int cm32181_read_als_it(struct cm32181_chip *cm32181, int *val2); 92 93 #ifdef CONFIG_ACPI 94 /** 95 * cm32181_acpi_get_cpm() - Get CPM object from ACPI 96 * @dev: pointer of struct device. 97 * @obj_name: pointer of ACPI object name. 98 * @values: pointer of array for return elements. 99 * @count: maximum size of return array. 100 * 101 * Convert ACPI CPM table to array. 102 * 103 * Return: -ENODEV for fail. Otherwise is number of elements. 104 */ 105 static int cm32181_acpi_get_cpm(struct device *dev, char *obj_name, 106 u64 *values, int count) 107 { 108 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 109 union acpi_object *cpm, *elem; 110 acpi_handle handle; 111 acpi_status status; 112 int i; 113 114 handle = ACPI_HANDLE(dev); 115 if (!handle) 116 return -ENODEV; 117 118 status = acpi_evaluate_object(handle, obj_name, NULL, &buffer); 119 if (ACPI_FAILURE(status)) { 120 dev_err(dev, "object %s not found\n", obj_name); 121 return -ENODEV; 122 } 123 124 cpm = buffer.pointer; 125 if (cpm->package.count > count) 126 dev_warn(dev, "%s table contains %u values, only using first %d values\n", 127 obj_name, cpm->package.count, count); 128 129 count = min_t(int, cpm->package.count, count); 130 for (i = 0; i < count; i++) { 131 elem = &(cpm->package.elements[i]); 132 values[i] = elem->integer.value; 133 } 134 135 kfree(buffer.pointer); 136 137 return count; 138 } 139 140 static void cm32181_acpi_parse_cpm_tables(struct cm32181_chip *cm32181) 141 { 142 u64 vals[CPM0_HEADER_SIZE + CM32181_CONF_REG_NUM]; 143 struct device *dev = cm32181->dev; 144 int i, count; 145 146 count = cm32181_acpi_get_cpm(dev, "CPM0", vals, ARRAY_SIZE(vals)); 147 if (count <= CPM0_HEADER_SIZE) 148 return; 149 150 count -= CPM0_HEADER_SIZE; 151 152 cm32181->init_regs_bitmap = vals[CPM0_REGS_BITMAP]; 153 cm32181->init_regs_bitmap &= GENMASK(count - 1, 0); 154 for_each_set_bit(i, &cm32181->init_regs_bitmap, count) 155 cm32181->conf_regs[i] = vals[CPM0_HEADER_SIZE + i]; 156 157 count = cm32181_acpi_get_cpm(dev, "CPM1", vals, ARRAY_SIZE(vals)); 158 if (count != CPM1_SIZE) 159 return; 160 161 cm32181->lux_per_bit = vals[CPM1_LUX_PER_BIT]; 162 163 /* Check for uncalibrated devices */ 164 if (vals[CPM1_CALIBSCALE] == CM32181_CALIBSCALE_DEFAULT) 165 return; 166 167 cm32181->calibscale = vals[CPM1_CALIBSCALE]; 168 /* CPM1 lux_per_bit is for the current it value */ 169 cm32181_read_als_it(cm32181, &cm32181->lux_per_bit_base_it); 170 } 171 #else 172 static void cm32181_acpi_parse_cpm_tables(struct cm32181_chip *cm32181) 173 { 174 } 175 #endif /* CONFIG_ACPI */ 176 177 /** 178 * cm32181_reg_init() - Initialize CM32181 registers 179 * @cm32181: pointer of struct cm32181. 180 * 181 * Initialize CM32181 ambient light sensor register to default values. 182 * 183 * Return: 0 for success; otherwise for error code. 184 */ 185 static int cm32181_reg_init(struct cm32181_chip *cm32181) 186 { 187 struct i2c_client *client = cm32181->client; 188 int i; 189 s32 ret; 190 191 ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ID); 192 if (ret < 0) 193 return ret; 194 195 /* check device ID */ 196 switch (ret & 0xFF) { 197 case 0x18: /* CM3218 */ 198 cm32181->num_als_it = ARRAY_SIZE(cm3218_als_it_bits); 199 cm32181->als_it_bits = cm3218_als_it_bits; 200 cm32181->als_it_values = cm3218_als_it_values; 201 break; 202 case 0x81: /* CM32181 */ 203 case 0x82: /* CM32182, fully compat. with CM32181 */ 204 cm32181->num_als_it = ARRAY_SIZE(cm32181_als_it_bits); 205 cm32181->als_it_bits = cm32181_als_it_bits; 206 cm32181->als_it_values = cm32181_als_it_values; 207 break; 208 default: 209 return -ENODEV; 210 } 211 212 /* Default Values */ 213 cm32181->conf_regs[CM32181_REG_ADDR_CMD] = 214 CM32181_CMD_ALS_IT_DEFAULT | CM32181_CMD_ALS_SM_DEFAULT; 215 cm32181->init_regs_bitmap = BIT(CM32181_REG_ADDR_CMD); 216 cm32181->calibscale = CM32181_CALIBSCALE_DEFAULT; 217 cm32181->lux_per_bit = CM32181_LUX_PER_BIT; 218 cm32181->lux_per_bit_base_it = CM32181_LUX_PER_BIT_BASE_IT; 219 220 if (ACPI_HANDLE(cm32181->dev)) 221 cm32181_acpi_parse_cpm_tables(cm32181); 222 223 /* Initialize registers*/ 224 for_each_set_bit(i, &cm32181->init_regs_bitmap, CM32181_CONF_REG_NUM) { 225 ret = i2c_smbus_write_word_data(client, i, 226 cm32181->conf_regs[i]); 227 if (ret < 0) 228 return ret; 229 } 230 231 return 0; 232 } 233 234 /** 235 * cm32181_read_als_it() - Get sensor integration time (ms) 236 * @cm32181: pointer of struct cm32181 237 * @val2: pointer of int to load the als_it value. 238 * 239 * Report the current integration time in milliseconds. 240 * 241 * Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL. 242 */ 243 static int cm32181_read_als_it(struct cm32181_chip *cm32181, int *val2) 244 { 245 u16 als_it; 246 int i; 247 248 als_it = cm32181->conf_regs[CM32181_REG_ADDR_CMD]; 249 als_it &= CM32181_CMD_ALS_IT_MASK; 250 als_it >>= CM32181_CMD_ALS_IT_SHIFT; 251 for (i = 0; i < cm32181->num_als_it; i++) { 252 if (als_it == cm32181->als_it_bits[i]) { 253 *val2 = cm32181->als_it_values[i]; 254 return IIO_VAL_INT_PLUS_MICRO; 255 } 256 } 257 258 return -EINVAL; 259 } 260 261 /** 262 * cm32181_write_als_it() - Write sensor integration time 263 * @cm32181: pointer of struct cm32181. 264 * @val: integration time by millisecond. 265 * 266 * Convert integration time (ms) to sensor value. 267 * 268 * Return: i2c_smbus_write_word_data command return value. 269 */ 270 static int cm32181_write_als_it(struct cm32181_chip *cm32181, int val) 271 { 272 struct i2c_client *client = cm32181->client; 273 u16 als_it; 274 int ret, i, n; 275 276 n = cm32181->num_als_it; 277 for (i = 0; i < n; i++) 278 if (val <= cm32181->als_it_values[i]) 279 break; 280 if (i >= n) 281 i = n - 1; 282 283 als_it = cm32181->als_it_bits[i]; 284 als_it <<= CM32181_CMD_ALS_IT_SHIFT; 285 286 mutex_lock(&cm32181->lock); 287 cm32181->conf_regs[CM32181_REG_ADDR_CMD] &= 288 ~CM32181_CMD_ALS_IT_MASK; 289 cm32181->conf_regs[CM32181_REG_ADDR_CMD] |= 290 als_it; 291 ret = i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD, 292 cm32181->conf_regs[CM32181_REG_ADDR_CMD]); 293 mutex_unlock(&cm32181->lock); 294 295 return ret; 296 } 297 298 /** 299 * cm32181_get_lux() - report current lux value 300 * @cm32181: pointer of struct cm32181. 301 * 302 * Convert sensor raw data to lux. It depends on integration 303 * time and calibscale variable. 304 * 305 * Return: Positive value is lux, otherwise is error code. 306 */ 307 static int cm32181_get_lux(struct cm32181_chip *cm32181) 308 { 309 struct i2c_client *client = cm32181->client; 310 int ret; 311 int als_it; 312 u64 lux; 313 314 ret = cm32181_read_als_it(cm32181, &als_it); 315 if (ret < 0) 316 return -EINVAL; 317 318 lux = cm32181->lux_per_bit; 319 lux *= cm32181->lux_per_bit_base_it; 320 lux = div_u64(lux, als_it); 321 322 ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ALS); 323 if (ret < 0) 324 return ret; 325 326 lux *= ret; 327 lux *= cm32181->calibscale; 328 lux = div_u64(lux, CM32181_CALIBSCALE_RESOLUTION); 329 lux = div_u64(lux, CM32181_LUX_PER_BIT_RESOLUTION); 330 331 if (lux > 0xFFFF) 332 lux = 0xFFFF; 333 334 return lux; 335 } 336 337 static int cm32181_read_raw(struct iio_dev *indio_dev, 338 struct iio_chan_spec const *chan, 339 int *val, int *val2, long mask) 340 { 341 struct cm32181_chip *cm32181 = iio_priv(indio_dev); 342 int ret; 343 344 switch (mask) { 345 case IIO_CHAN_INFO_PROCESSED: 346 ret = cm32181_get_lux(cm32181); 347 if (ret < 0) 348 return ret; 349 *val = ret; 350 return IIO_VAL_INT; 351 case IIO_CHAN_INFO_CALIBSCALE: 352 *val = cm32181->calibscale; 353 return IIO_VAL_INT; 354 case IIO_CHAN_INFO_INT_TIME: 355 *val = 0; 356 ret = cm32181_read_als_it(cm32181, val2); 357 return ret; 358 } 359 360 return -EINVAL; 361 } 362 363 static int cm32181_write_raw(struct iio_dev *indio_dev, 364 struct iio_chan_spec const *chan, 365 int val, int val2, long mask) 366 { 367 struct cm32181_chip *cm32181 = iio_priv(indio_dev); 368 int ret; 369 370 switch (mask) { 371 case IIO_CHAN_INFO_CALIBSCALE: 372 cm32181->calibscale = val; 373 return val; 374 case IIO_CHAN_INFO_INT_TIME: 375 ret = cm32181_write_als_it(cm32181, val2); 376 return ret; 377 } 378 379 return -EINVAL; 380 } 381 382 /** 383 * cm32181_get_it_available() - Get available ALS IT value 384 * @dev: pointer of struct device. 385 * @attr: pointer of struct device_attribute. 386 * @buf: pointer of return string buffer. 387 * 388 * Display the available integration time values by millisecond. 389 * 390 * Return: string length. 391 */ 392 static ssize_t cm32181_get_it_available(struct device *dev, 393 struct device_attribute *attr, char *buf) 394 { 395 struct cm32181_chip *cm32181 = iio_priv(dev_to_iio_dev(dev)); 396 int i, n, len; 397 398 n = cm32181->num_als_it; 399 for (i = 0, len = 0; i < n; i++) 400 len += sprintf(buf + len, "0.%06u ", cm32181->als_it_values[i]); 401 return len + sprintf(buf + len, "\n"); 402 } 403 404 static const struct iio_chan_spec cm32181_channels[] = { 405 { 406 .type = IIO_LIGHT, 407 .info_mask_separate = 408 BIT(IIO_CHAN_INFO_PROCESSED) | 409 BIT(IIO_CHAN_INFO_CALIBSCALE) | 410 BIT(IIO_CHAN_INFO_INT_TIME), 411 } 412 }; 413 414 static IIO_DEVICE_ATTR(in_illuminance_integration_time_available, 415 S_IRUGO, cm32181_get_it_available, NULL, 0); 416 417 static struct attribute *cm32181_attributes[] = { 418 &iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr, 419 NULL, 420 }; 421 422 static const struct attribute_group cm32181_attribute_group = { 423 .attrs = cm32181_attributes 424 }; 425 426 static const struct iio_info cm32181_info = { 427 .read_raw = &cm32181_read_raw, 428 .write_raw = &cm32181_write_raw, 429 .attrs = &cm32181_attribute_group, 430 }; 431 432 static void cm32181_unregister_dummy_client(void *data) 433 { 434 struct i2c_client *client = data; 435 436 /* Unregister the dummy client */ 437 i2c_unregister_device(client); 438 } 439 440 static int cm32181_probe(struct i2c_client *client) 441 { 442 struct device *dev = &client->dev; 443 struct cm32181_chip *cm32181; 444 struct iio_dev *indio_dev; 445 int ret; 446 447 indio_dev = devm_iio_device_alloc(dev, sizeof(*cm32181)); 448 if (!indio_dev) 449 return -ENOMEM; 450 451 i2c_set_clientdata(client, indio_dev); 452 453 /* 454 * Some ACPI systems list 2 I2C resources for the CM3218 sensor, the 455 * SMBus Alert Response Address (ARA, 0x0c) and the actual I2C address. 456 * Detect this and take the following step to deal with it: 457 * 1. When a SMBus Alert capable sensor has an Alert asserted, it will 458 * not respond on its actual I2C address. Read a byte from the ARA 459 * to clear any pending Alerts. 460 * 2. Create a "dummy" client for the actual I2C address and 461 * use that client to communicate with the sensor. 462 */ 463 if (ACPI_HANDLE(dev) && client->addr == SMBUS_ALERT_RESPONSE_ADDRESS) { 464 struct i2c_board_info board_info = { .type = "dummy" }; 465 466 i2c_smbus_read_byte(client); 467 468 client = i2c_acpi_new_device(dev, 1, &board_info); 469 if (IS_ERR(client)) 470 return PTR_ERR(client); 471 472 ret = devm_add_action_or_reset(dev, cm32181_unregister_dummy_client, client); 473 if (ret) 474 return ret; 475 } 476 477 cm32181 = iio_priv(indio_dev); 478 cm32181->client = client; 479 cm32181->dev = dev; 480 481 mutex_init(&cm32181->lock); 482 indio_dev->channels = cm32181_channels; 483 indio_dev->num_channels = ARRAY_SIZE(cm32181_channels); 484 indio_dev->info = &cm32181_info; 485 indio_dev->name = dev_name(dev); 486 indio_dev->modes = INDIO_DIRECT_MODE; 487 488 ret = cm32181_reg_init(cm32181); 489 if (ret) { 490 dev_err(dev, "%s: register init failed\n", __func__); 491 return ret; 492 } 493 494 ret = devm_iio_device_register(dev, indio_dev); 495 if (ret) { 496 dev_err(dev, "%s: regist device failed\n", __func__); 497 return ret; 498 } 499 500 return 0; 501 } 502 503 static int cm32181_suspend(struct device *dev) 504 { 505 struct cm32181_chip *cm32181 = iio_priv(dev_get_drvdata(dev)); 506 struct i2c_client *client = cm32181->client; 507 508 return i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD, 509 CM32181_CMD_ALS_DISABLE); 510 } 511 512 static int cm32181_resume(struct device *dev) 513 { 514 struct cm32181_chip *cm32181 = iio_priv(dev_get_drvdata(dev)); 515 struct i2c_client *client = cm32181->client; 516 517 return i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD, 518 cm32181->conf_regs[CM32181_REG_ADDR_CMD]); 519 } 520 521 static DEFINE_SIMPLE_DEV_PM_OPS(cm32181_pm_ops, cm32181_suspend, cm32181_resume); 522 523 static const struct of_device_id cm32181_of_match[] = { 524 { .compatible = "capella,cm3218" }, 525 { .compatible = "capella,cm32181" }, 526 { } 527 }; 528 MODULE_DEVICE_TABLE(of, cm32181_of_match); 529 530 #ifdef CONFIG_ACPI 531 static const struct acpi_device_id cm32181_acpi_match[] = { 532 { "CPLM3218", 0 }, 533 { } 534 }; 535 MODULE_DEVICE_TABLE(acpi, cm32181_acpi_match); 536 #endif 537 538 static struct i2c_driver cm32181_driver = { 539 .driver = { 540 .name = "cm32181", 541 .acpi_match_table = ACPI_PTR(cm32181_acpi_match), 542 .of_match_table = cm32181_of_match, 543 .pm = pm_sleep_ptr(&cm32181_pm_ops), 544 }, 545 .probe_new = cm32181_probe, 546 }; 547 548 module_i2c_driver(cm32181_driver); 549 550 MODULE_AUTHOR("Kevin Tsai <ktsai@capellamicro.com>"); 551 MODULE_DESCRIPTION("CM32181 ambient light sensor driver"); 552 MODULE_LICENSE("GPL"); 553