1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * ROHM BH1710/BH1715/BH1721/BH1750/BH1751 ambient light sensor driver 4 * 5 * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com> 6 * 7 * Data sheets: 8 * http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1710fvc-e.pdf 9 * http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1715fvc-e.pdf 10 * http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1721fvc-e.pdf 11 * http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1750fvi-e.pdf 12 * http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1751fvi-e.pdf 13 * 14 * 7-bit I2C slave addresses: 15 * 0x23 (ADDR pin low) 16 * 0x5C (ADDR pin high) 17 * 18 */ 19 20 #include <linux/delay.h> 21 #include <linux/i2c.h> 22 #include <linux/iio/iio.h> 23 #include <linux/iio/sysfs.h> 24 #include <linux/module.h> 25 #include <linux/gpio/consumer.h> 26 27 #define BH1750_POWER_DOWN 0x00 28 #define BH1750_ONE_TIME_H_RES_MODE 0x20 /* auto-mode for BH1721 */ 29 #define BH1750_CHANGE_INT_TIME_H_BIT 0x40 30 #define BH1750_CHANGE_INT_TIME_L_BIT 0x60 31 32 /* Define the reset delay time in microseconds */ 33 #define BH1750_RESET_DELAY_US 10000 /* 10ms */ 34 35 enum { 36 BH1710, 37 BH1721, 38 BH1750, 39 }; 40 41 struct bh1750_chip_info; 42 struct bh1750_data { 43 struct i2c_client *client; 44 struct mutex lock; 45 const struct bh1750_chip_info *chip_info; 46 u16 mtreg; 47 struct gpio_desc *reset_gpio; 48 }; 49 50 struct bh1750_chip_info { 51 u16 mtreg_min; 52 u16 mtreg_max; 53 u16 mtreg_default; 54 int mtreg_to_usec; 55 int mtreg_to_scale; 56 57 /* 58 * For BH1710/BH1721 all possible integration time values won't fit 59 * into one page so displaying is limited to every second one. 60 * Note, that user can still write proper values which were not 61 * listed. 62 */ 63 int inc; 64 65 u16 int_time_low_mask; 66 u16 int_time_high_mask; 67 }; 68 69 static const struct bh1750_chip_info bh1750_chip_info_tbl[] = { 70 [BH1710] = { 140, 1022, 300, 400, 250000000, 2, 0x001F, 0x03E0 }, 71 [BH1721] = { 140, 1020, 300, 400, 250000000, 2, 0x0010, 0x03E0 }, 72 [BH1750] = { 31, 254, 69, 1740, 57500000, 1, 0x001F, 0x00E0 }, 73 }; 74 75 static int bh1750_change_int_time(struct bh1750_data *data, int usec) 76 { 77 int ret; 78 u16 val; 79 u8 regval; 80 const struct bh1750_chip_info *chip_info = data->chip_info; 81 82 if ((usec % chip_info->mtreg_to_usec) != 0) 83 return -EINVAL; 84 85 val = usec / chip_info->mtreg_to_usec; 86 if (val < chip_info->mtreg_min || val > chip_info->mtreg_max) 87 return -EINVAL; 88 89 ret = i2c_smbus_write_byte(data->client, BH1750_POWER_DOWN); 90 if (ret < 0) 91 return ret; 92 93 regval = (val & chip_info->int_time_high_mask) >> 5; 94 ret = i2c_smbus_write_byte(data->client, 95 BH1750_CHANGE_INT_TIME_H_BIT | regval); 96 if (ret < 0) 97 return ret; 98 99 regval = val & chip_info->int_time_low_mask; 100 ret = i2c_smbus_write_byte(data->client, 101 BH1750_CHANGE_INT_TIME_L_BIT | regval); 102 if (ret < 0) 103 return ret; 104 105 data->mtreg = val; 106 107 return 0; 108 } 109 110 static int bh1750_read(struct bh1750_data *data, int *val) 111 { 112 int ret; 113 __be16 result; 114 const struct bh1750_chip_info *chip_info = data->chip_info; 115 unsigned long delay = chip_info->mtreg_to_usec * data->mtreg; 116 117 /* 118 * BH1721 will enter continuous mode on receiving this command. 119 * Note, that this eliminates need for bh1750_resume(). 120 */ 121 ret = i2c_smbus_write_byte(data->client, BH1750_ONE_TIME_H_RES_MODE); 122 if (ret < 0) 123 return ret; 124 125 usleep_range(delay + 15000, delay + 40000); 126 127 ret = i2c_master_recv(data->client, (char *)&result, 2); 128 if (ret < 0) 129 return ret; 130 131 *val = be16_to_cpu(result); 132 133 return 0; 134 } 135 136 static int bh1750_read_raw(struct iio_dev *indio_dev, 137 struct iio_chan_spec const *chan, 138 int *val, int *val2, long mask) 139 { 140 int ret, tmp; 141 struct bh1750_data *data = iio_priv(indio_dev); 142 const struct bh1750_chip_info *chip_info = data->chip_info; 143 144 switch (mask) { 145 case IIO_CHAN_INFO_RAW: 146 switch (chan->type) { 147 case IIO_LIGHT: 148 mutex_lock(&data->lock); 149 ret = bh1750_read(data, val); 150 mutex_unlock(&data->lock); 151 if (ret < 0) 152 return ret; 153 154 return IIO_VAL_INT; 155 default: 156 return -EINVAL; 157 } 158 case IIO_CHAN_INFO_SCALE: 159 tmp = chip_info->mtreg_to_scale / data->mtreg; 160 *val = tmp / 1000000; 161 *val2 = tmp % 1000000; 162 return IIO_VAL_INT_PLUS_MICRO; 163 case IIO_CHAN_INFO_INT_TIME: 164 *val = 0; 165 *val2 = chip_info->mtreg_to_usec * data->mtreg; 166 return IIO_VAL_INT_PLUS_MICRO; 167 default: 168 return -EINVAL; 169 } 170 } 171 172 static int bh1750_write_raw(struct iio_dev *indio_dev, 173 struct iio_chan_spec const *chan, 174 int val, int val2, long mask) 175 { 176 int ret; 177 struct bh1750_data *data = iio_priv(indio_dev); 178 179 switch (mask) { 180 case IIO_CHAN_INFO_INT_TIME: 181 if (val != 0) 182 return -EINVAL; 183 184 mutex_lock(&data->lock); 185 ret = bh1750_change_int_time(data, val2); 186 mutex_unlock(&data->lock); 187 return ret; 188 default: 189 return -EINVAL; 190 } 191 } 192 193 static ssize_t bh1750_show_int_time_available(struct device *dev, 194 struct device_attribute *attr, char *buf) 195 { 196 int i; 197 size_t len = 0; 198 struct bh1750_data *data = iio_priv(dev_to_iio_dev(dev)); 199 const struct bh1750_chip_info *chip_info = data->chip_info; 200 201 for (i = chip_info->mtreg_min; i <= chip_info->mtreg_max; i += chip_info->inc) 202 len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06d ", 203 chip_info->mtreg_to_usec * i); 204 205 buf[len - 1] = '\n'; 206 207 return len; 208 } 209 210 static IIO_DEV_ATTR_INT_TIME_AVAIL(bh1750_show_int_time_available); 211 212 static struct attribute *bh1750_attributes[] = { 213 &iio_dev_attr_integration_time_available.dev_attr.attr, 214 NULL, 215 }; 216 217 static const struct attribute_group bh1750_attribute_group = { 218 .attrs = bh1750_attributes, 219 }; 220 221 static const struct iio_info bh1750_info = { 222 .attrs = &bh1750_attribute_group, 223 .read_raw = bh1750_read_raw, 224 .write_raw = bh1750_write_raw, 225 }; 226 227 static const struct iio_chan_spec bh1750_channels[] = { 228 { 229 .type = IIO_LIGHT, 230 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 231 BIT(IIO_CHAN_INFO_SCALE) | 232 BIT(IIO_CHAN_INFO_INT_TIME) 233 } 234 }; 235 236 static int bh1750_probe(struct i2c_client *client) 237 { 238 const struct i2c_device_id *id = i2c_client_get_device_id(client); 239 int ret, usec; 240 struct bh1750_data *data; 241 struct iio_dev *indio_dev; 242 243 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C | 244 I2C_FUNC_SMBUS_WRITE_BYTE)) 245 return -EOPNOTSUPP; 246 247 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 248 if (!indio_dev) 249 return -ENOMEM; 250 251 data = iio_priv(indio_dev); 252 i2c_set_clientdata(client, indio_dev); 253 data->client = client; 254 data->chip_info = &bh1750_chip_info_tbl[id->driver_data]; 255 256 /* Get reset GPIO from device tree */ 257 data->reset_gpio = devm_gpiod_get_optional(&client->dev, 258 "reset", GPIOD_OUT_HIGH); 259 260 if (IS_ERR(data->reset_gpio)) 261 return dev_err_probe(&client->dev, PTR_ERR(data->reset_gpio), 262 "Failed to get reset GPIO\n"); 263 264 /* Perform hardware reset if GPIO is provided */ 265 if (data->reset_gpio) { 266 /* Perform reset sequence: low-high */ 267 gpiod_set_value_cansleep(data->reset_gpio, 1); 268 fsleep(BH1750_RESET_DELAY_US); 269 gpiod_set_value_cansleep(data->reset_gpio, 0); 270 fsleep(BH1750_RESET_DELAY_US); 271 272 dev_dbg(&client->dev, "BH1750 reset completed via GPIO\n"); 273 } 274 275 usec = data->chip_info->mtreg_to_usec * data->chip_info->mtreg_default; 276 ret = bh1750_change_int_time(data, usec); 277 if (ret < 0) 278 return ret; 279 280 mutex_init(&data->lock); 281 indio_dev->info = &bh1750_info; 282 indio_dev->name = id->name; 283 indio_dev->channels = bh1750_channels; 284 indio_dev->num_channels = ARRAY_SIZE(bh1750_channels); 285 indio_dev->modes = INDIO_DIRECT_MODE; 286 287 return iio_device_register(indio_dev); 288 } 289 290 static void bh1750_remove(struct i2c_client *client) 291 { 292 struct iio_dev *indio_dev = i2c_get_clientdata(client); 293 struct bh1750_data *data = iio_priv(indio_dev); 294 295 iio_device_unregister(indio_dev); 296 297 mutex_lock(&data->lock); 298 i2c_smbus_write_byte(client, BH1750_POWER_DOWN); 299 mutex_unlock(&data->lock); 300 } 301 302 static int bh1750_suspend(struct device *dev) 303 { 304 int ret; 305 struct bh1750_data *data = 306 iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 307 308 /* 309 * This is mainly for BH1721 which doesn't enter power down 310 * mode automatically. 311 */ 312 mutex_lock(&data->lock); 313 ret = i2c_smbus_write_byte(data->client, BH1750_POWER_DOWN); 314 mutex_unlock(&data->lock); 315 316 return ret; 317 } 318 319 static DEFINE_SIMPLE_DEV_PM_OPS(bh1750_pm_ops, bh1750_suspend, NULL); 320 321 static const struct i2c_device_id bh1750_id[] = { 322 { "bh1710", BH1710 }, 323 { "bh1715", BH1750 }, 324 { "bh1721", BH1721 }, 325 { "bh1750", BH1750 }, 326 { "bh1751", BH1750 }, 327 { } 328 }; 329 MODULE_DEVICE_TABLE(i2c, bh1750_id); 330 331 static const struct of_device_id bh1750_of_match[] = { 332 { .compatible = "rohm,bh1710", }, 333 { .compatible = "rohm,bh1715", }, 334 { .compatible = "rohm,bh1721", }, 335 { .compatible = "rohm,bh1750", }, 336 { .compatible = "rohm,bh1751", }, 337 { } 338 }; 339 MODULE_DEVICE_TABLE(of, bh1750_of_match); 340 341 static struct i2c_driver bh1750_driver = { 342 .driver = { 343 .name = "bh1750", 344 .of_match_table = bh1750_of_match, 345 .pm = pm_sleep_ptr(&bh1750_pm_ops), 346 }, 347 .probe = bh1750_probe, 348 .remove = bh1750_remove, 349 .id_table = bh1750_id, 350 351 }; 352 module_i2c_driver(bh1750_driver); 353 354 MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>"); 355 MODULE_DESCRIPTION("ROHM BH1710/BH1715/BH1721/BH1750/BH1751 als driver"); 356 MODULE_LICENSE("GPL v2"); 357