1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * CM3232 Ambient Light Sensor 4 * 5 * Copyright (C) 2014-2015 Capella Microsystems Inc. 6 * Author: Kevin Tsai <ktsai@capellamicro.com> 7 * 8 * IIO driver for CM3232 (7-bit I2C slave address 0x10). 9 */ 10 11 #include <linux/i2c.h> 12 #include <linux/module.h> 13 #include <linux/mod_devicetable.h> 14 #include <linux/iio/iio.h> 15 #include <linux/iio/sysfs.h> 16 #include <linux/init.h> 17 18 /* Registers Address */ 19 #define CM3232_REG_ADDR_CMD 0x00 20 #define CM3232_REG_ADDR_ALS 0x50 21 #define CM3232_REG_ADDR_ID 0x53 22 23 #define CM3232_CMD_ALS_DISABLE BIT(0) 24 25 #define CM3232_CMD_ALS_IT_SHIFT 2 26 #define CM3232_CMD_ALS_IT_MASK (BIT(2) | BIT(3) | BIT(4)) 27 #define CM3232_CMD_ALS_IT_DEFAULT (0x01 << CM3232_CMD_ALS_IT_SHIFT) 28 29 #define CM3232_CMD_ALS_RESET BIT(6) 30 31 #define CM3232_CMD_DEFAULT CM3232_CMD_ALS_IT_DEFAULT 32 33 #define CM3232_HW_ID 0x32 34 #define CM3232_CALIBSCALE_DEFAULT 100000 35 #define CM3232_CALIBSCALE_RESOLUTION 100000 36 #define CM3232_MLUX_PER_LUX 1000 37 38 #define CM3232_MLUX_PER_BIT_DEFAULT 64 39 #define CM3232_MLUX_PER_BIT_BASE_IT 100000 40 41 static const struct { 42 int val; 43 int val2; 44 u8 it; 45 } cm3232_als_it_scales[] = { 46 {0, 100000, 0}, /* 0.100000 */ 47 {0, 200000, 1}, /* 0.200000 */ 48 {0, 400000, 2}, /* 0.400000 */ 49 {0, 800000, 3}, /* 0.800000 */ 50 {1, 600000, 4}, /* 1.600000 */ 51 {3, 200000, 5}, /* 3.200000 */ 52 }; 53 54 struct cm3232_als_info { 55 u8 regs_cmd_default; 56 u8 hw_id; 57 int mlux_per_bit; 58 int mlux_per_bit_base_it; 59 }; 60 61 static const struct cm3232_als_info cm3232_als_info_default = { 62 .regs_cmd_default = CM3232_CMD_DEFAULT, 63 .hw_id = CM3232_HW_ID, 64 .mlux_per_bit = CM3232_MLUX_PER_BIT_DEFAULT, 65 .mlux_per_bit_base_it = CM3232_MLUX_PER_BIT_BASE_IT, 66 }; 67 68 struct cm3232_chip { 69 struct i2c_client *client; 70 const struct cm3232_als_info *als_info; 71 int calibscale; 72 u8 regs_cmd; 73 u16 regs_als; 74 }; 75 76 /** 77 * cm3232_reg_init() - Initialize CM3232 78 * @chip: pointer of struct cm3232_chip. 79 * 80 * Check and initialize CM3232 ambient light sensor. 81 * 82 * Return: 0 for success; otherwise for error code. 83 */ 84 static int cm3232_reg_init(struct cm3232_chip *chip) 85 { 86 struct i2c_client *client = chip->client; 87 s32 ret; 88 89 chip->als_info = &cm3232_als_info_default; 90 91 /* Disable and reset device */ 92 chip->regs_cmd = CM3232_CMD_ALS_DISABLE | CM3232_CMD_ALS_RESET; 93 ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD, 94 chip->regs_cmd); 95 if (ret < 0) { 96 dev_err(&chip->client->dev, "Error writing reg_cmd\n"); 97 return ret; 98 } 99 100 /* Identify device */ 101 ret = i2c_smbus_read_word_data(client, CM3232_REG_ADDR_ID); 102 if (ret < 0) { 103 dev_err(&chip->client->dev, "Error reading addr_id\n"); 104 return ret; 105 } 106 107 if ((ret & 0xFF) != chip->als_info->hw_id) 108 return -ENODEV; 109 110 /* Register default value */ 111 chip->regs_cmd = chip->als_info->regs_cmd_default; 112 113 /* Configure register */ 114 ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD, 115 chip->regs_cmd); 116 if (ret < 0) 117 dev_err(&chip->client->dev, "Error writing reg_cmd\n"); 118 119 return ret; 120 } 121 122 /** 123 * cm3232_read_als_it() - Get sensor integration time 124 * @chip: pointer of struct cm3232_chip 125 * @val: pointer of int to load the integration (sec). 126 * @val2: pointer of int to load the integration time (microsecond). 127 * 128 * Report the current integration time. 129 * 130 * Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL. 131 */ 132 static int cm3232_read_als_it(struct cm3232_chip *chip, int *val, int *val2) 133 { 134 u16 als_it; 135 int i; 136 137 als_it = chip->regs_cmd; 138 als_it &= CM3232_CMD_ALS_IT_MASK; 139 als_it >>= CM3232_CMD_ALS_IT_SHIFT; 140 for (i = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++) { 141 if (als_it == cm3232_als_it_scales[i].it) { 142 *val = cm3232_als_it_scales[i].val; 143 *val2 = cm3232_als_it_scales[i].val2; 144 return IIO_VAL_INT_PLUS_MICRO; 145 } 146 } 147 148 return -EINVAL; 149 } 150 151 /** 152 * cm3232_write_als_it() - Write sensor integration time 153 * @chip: pointer of struct cm3232_chip. 154 * @val: integration time in second. 155 * @val2: integration time in microsecond. 156 * 157 * Convert integration time to sensor value. 158 * 159 * Return: i2c_smbus_write_byte_data command return value. 160 */ 161 static int cm3232_write_als_it(struct cm3232_chip *chip, int val, int val2) 162 { 163 struct i2c_client *client = chip->client; 164 u16 als_it, cmd; 165 int i; 166 s32 ret; 167 168 for (i = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++) { 169 if (val == cm3232_als_it_scales[i].val && 170 val2 == cm3232_als_it_scales[i].val2) { 171 172 als_it = cm3232_als_it_scales[i].it; 173 als_it <<= CM3232_CMD_ALS_IT_SHIFT; 174 175 cmd = chip->regs_cmd & ~CM3232_CMD_ALS_IT_MASK; 176 cmd |= als_it; 177 ret = i2c_smbus_write_byte_data(client, 178 CM3232_REG_ADDR_CMD, 179 cmd); 180 if (ret < 0) 181 return ret; 182 chip->regs_cmd = cmd; 183 return 0; 184 } 185 } 186 return -EINVAL; 187 } 188 189 /** 190 * cm3232_get_lux() - report current lux value 191 * @chip: pointer of struct cm3232_chip. 192 * 193 * Convert sensor data to lux. It depends on integration 194 * time and calibscale variable. 195 * 196 * Return: Zero or positive value is lux, otherwise error code. 197 */ 198 static int cm3232_get_lux(struct cm3232_chip *chip) 199 { 200 struct i2c_client *client = chip->client; 201 const struct cm3232_als_info *als_info = chip->als_info; 202 int ret; 203 int val, val2; 204 int als_it; 205 u64 lux; 206 207 /* Calculate mlux per bit based on als_it */ 208 ret = cm3232_read_als_it(chip, &val, &val2); 209 if (ret < 0) 210 return -EINVAL; 211 als_it = val * 1000000 + val2; 212 lux = (__force u64)als_info->mlux_per_bit; 213 lux *= als_info->mlux_per_bit_base_it; 214 lux = div_u64(lux, als_it); 215 216 ret = i2c_smbus_read_word_data(client, CM3232_REG_ADDR_ALS); 217 if (ret < 0) { 218 dev_err(&client->dev, "Error reading reg_addr_als\n"); 219 return ret; 220 } 221 222 chip->regs_als = (u16)ret; 223 lux *= chip->regs_als; 224 lux *= chip->calibscale; 225 lux = div_u64(lux, CM3232_CALIBSCALE_RESOLUTION); 226 lux = div_u64(lux, CM3232_MLUX_PER_LUX); 227 228 if (lux > 0xFFFF) 229 lux = 0xFFFF; 230 231 return (int)lux; 232 } 233 234 static int cm3232_read_raw(struct iio_dev *indio_dev, 235 struct iio_chan_spec const *chan, 236 int *val, int *val2, long mask) 237 { 238 struct cm3232_chip *chip = iio_priv(indio_dev); 239 int ret; 240 241 switch (mask) { 242 case IIO_CHAN_INFO_PROCESSED: 243 ret = cm3232_get_lux(chip); 244 if (ret < 0) 245 return ret; 246 *val = ret; 247 return IIO_VAL_INT; 248 case IIO_CHAN_INFO_CALIBSCALE: 249 *val = chip->calibscale; 250 return IIO_VAL_INT; 251 case IIO_CHAN_INFO_INT_TIME: 252 return cm3232_read_als_it(chip, val, val2); 253 } 254 255 return -EINVAL; 256 } 257 258 static int cm3232_write_raw(struct iio_dev *indio_dev, 259 struct iio_chan_spec const *chan, 260 int val, int val2, long mask) 261 { 262 struct cm3232_chip *chip = iio_priv(indio_dev); 263 264 switch (mask) { 265 case IIO_CHAN_INFO_CALIBSCALE: 266 chip->calibscale = val; 267 return 0; 268 case IIO_CHAN_INFO_INT_TIME: 269 return cm3232_write_als_it(chip, val, val2); 270 } 271 272 return -EINVAL; 273 } 274 275 /** 276 * cm3232_get_it_available() - Get available ALS IT value 277 * @dev: pointer of struct device. 278 * @attr: pointer of struct device_attribute. 279 * @buf: pointer of return string buffer. 280 * 281 * Display the available integration time in second. 282 * 283 * Return: string length. 284 */ 285 static ssize_t cm3232_get_it_available(struct device *dev, 286 struct device_attribute *attr, char *buf) 287 { 288 int i, len; 289 290 for (i = 0, len = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++) 291 len += scnprintf(buf + len, PAGE_SIZE - len, "%u.%06u ", 292 cm3232_als_it_scales[i].val, 293 cm3232_als_it_scales[i].val2); 294 return len + scnprintf(buf + len, PAGE_SIZE - len, "\n"); 295 } 296 297 static const struct iio_chan_spec cm3232_channels[] = { 298 { 299 .type = IIO_LIGHT, 300 .info_mask_separate = 301 BIT(IIO_CHAN_INFO_PROCESSED) | 302 BIT(IIO_CHAN_INFO_CALIBSCALE) | 303 BIT(IIO_CHAN_INFO_INT_TIME), 304 } 305 }; 306 307 static IIO_DEVICE_ATTR(in_illuminance_integration_time_available, 308 S_IRUGO, cm3232_get_it_available, NULL, 0); 309 310 static struct attribute *cm3232_attributes[] = { 311 &iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr, 312 NULL, 313 }; 314 315 static const struct attribute_group cm3232_attribute_group = { 316 .attrs = cm3232_attributes 317 }; 318 319 static const struct iio_info cm3232_info = { 320 .read_raw = &cm3232_read_raw, 321 .write_raw = &cm3232_write_raw, 322 .attrs = &cm3232_attribute_group, 323 }; 324 325 static int cm3232_probe(struct i2c_client *client) 326 { 327 const struct i2c_device_id *id = i2c_client_get_device_id(client); 328 struct cm3232_chip *chip; 329 struct iio_dev *indio_dev; 330 int ret; 331 332 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip)); 333 if (!indio_dev) 334 return -ENOMEM; 335 336 chip = iio_priv(indio_dev); 337 i2c_set_clientdata(client, indio_dev); 338 chip->client = client; 339 chip->calibscale = CM3232_CALIBSCALE_DEFAULT; 340 341 indio_dev->channels = cm3232_channels; 342 indio_dev->num_channels = ARRAY_SIZE(cm3232_channels); 343 indio_dev->info = &cm3232_info; 344 indio_dev->name = id->name; 345 indio_dev->modes = INDIO_DIRECT_MODE; 346 347 ret = cm3232_reg_init(chip); 348 if (ret) { 349 dev_err(&client->dev, 350 "%s: register init failed\n", 351 __func__); 352 return ret; 353 } 354 355 return iio_device_register(indio_dev); 356 } 357 358 static void cm3232_remove(struct i2c_client *client) 359 { 360 struct iio_dev *indio_dev = i2c_get_clientdata(client); 361 362 i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD, 363 CM3232_CMD_ALS_DISABLE); 364 365 iio_device_unregister(indio_dev); 366 } 367 368 static const struct i2c_device_id cm3232_id[] = { 369 { "cm3232" }, 370 { } 371 }; 372 373 static int cm3232_suspend(struct device *dev) 374 { 375 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev)); 376 struct cm3232_chip *chip = iio_priv(indio_dev); 377 struct i2c_client *client = chip->client; 378 int ret; 379 380 chip->regs_cmd |= CM3232_CMD_ALS_DISABLE; 381 ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD, 382 chip->regs_cmd); 383 384 return ret; 385 } 386 387 static int cm3232_resume(struct device *dev) 388 { 389 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev)); 390 struct cm3232_chip *chip = iio_priv(indio_dev); 391 struct i2c_client *client = chip->client; 392 int ret; 393 394 chip->regs_cmd &= ~CM3232_CMD_ALS_DISABLE; 395 ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD, 396 chip->regs_cmd | CM3232_CMD_ALS_RESET); 397 398 return ret; 399 } 400 401 static DEFINE_SIMPLE_DEV_PM_OPS(cm3232_pm_ops, cm3232_suspend, cm3232_resume); 402 403 MODULE_DEVICE_TABLE(i2c, cm3232_id); 404 405 static const struct of_device_id cm3232_of_match[] = { 406 {.compatible = "capella,cm3232"}, 407 { } 408 }; 409 MODULE_DEVICE_TABLE(of, cm3232_of_match); 410 411 static struct i2c_driver cm3232_driver = { 412 .driver = { 413 .name = "cm3232", 414 .of_match_table = cm3232_of_match, 415 .pm = pm_sleep_ptr(&cm3232_pm_ops), 416 }, 417 .id_table = cm3232_id, 418 .probe = cm3232_probe, 419 .remove = cm3232_remove, 420 }; 421 422 module_i2c_driver(cm3232_driver); 423 424 MODULE_AUTHOR("Kevin Tsai <ktsai@capellamicro.com>"); 425 MODULE_DESCRIPTION("CM3232 ambient light sensor driver"); 426 MODULE_LICENSE("GPL"); 427