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