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1// SPDX-License-Identifier: GPL-2.02/*3 * ROHM BH1710/BH1715/BH1721/BH1750/BH1751 ambient light sensor driver4 *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.pdf9 * http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1715fvc-e.pdf10 * http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1721fvc-e.pdf11 * http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1750fvi-e.pdf12 * http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1751fvi-e.pdf13 *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 0x0027#define BH1750_ONE_TIME_H_RES_MODE 0x20 /* auto-mode for BH1721 */28#define BH1750_CHANGE_INT_TIME_H_BIT 0x4029#define BH1750_CHANGE_INT_TIME_L_BIT 0x6030 31enum {32 BH1710,33 BH1721,34 BH1750,35};36 37struct bh1750_chip_info;38struct bh1750_data {39 struct i2c_client *client;40 struct mutex lock;41 const struct bh1750_chip_info *chip_info;42 u16 mtreg;43};44 45struct 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 fit54 * into one page so displaying is limited to every second one.55 * Note, that user can still write proper values which were not56 * listed.57 */58 int inc;59 60 u16 int_time_low_mask;61 u16 int_time_high_mask;62};63 64static 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 70static 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 105static 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 131static 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 167static 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 188static 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 205static IIO_DEV_ATTR_INT_TIME_AVAIL(bh1750_show_int_time_available);206 207static struct attribute *bh1750_attributes[] = {208 &iio_dev_attr_integration_time_available.dev_attr.attr,209 NULL,210};211 212static const struct attribute_group bh1750_attribute_group = {213 .attrs = bh1750_attributes,214};215 216static 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 222static 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 231static int bh1750_probe(struct i2c_client *client)232{233 const struct i2c_device_id *id = i2c_client_get_device_id(client);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 266static void 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 278static int bh1750_suspend(struct device *dev)279{280 int ret;281 struct bh1750_data *data =282 iio_priv(i2c_get_clientdata(to_i2c_client(dev)));283 284 /*285 * This is mainly for BH1721 which doesn't enter power down286 * mode automatically.287 */288 mutex_lock(&data->lock);289 ret = i2c_smbus_write_byte(data->client, BH1750_POWER_DOWN);290 mutex_unlock(&data->lock);291 292 return ret;293}294 295static DEFINE_SIMPLE_DEV_PM_OPS(bh1750_pm_ops, bh1750_suspend, NULL);296 297static const struct i2c_device_id bh1750_id[] = {298 { "bh1710", BH1710 },299 { "bh1715", BH1750 },300 { "bh1721", BH1721 },301 { "bh1750", BH1750 },302 { "bh1751", BH1750 },303 { }304};305MODULE_DEVICE_TABLE(i2c, bh1750_id);306 307static const struct of_device_id bh1750_of_match[] = {308 { .compatible = "rohm,bh1710", },309 { .compatible = "rohm,bh1715", },310 { .compatible = "rohm,bh1721", },311 { .compatible = "rohm,bh1750", },312 { .compatible = "rohm,bh1751", },313 { }314};315MODULE_DEVICE_TABLE(of, bh1750_of_match);316 317static struct i2c_driver bh1750_driver = {318 .driver = {319 .name = "bh1750",320 .of_match_table = bh1750_of_match,321 .pm = pm_sleep_ptr(&bh1750_pm_ops),322 },323 .probe = bh1750_probe,324 .remove = bh1750_remove,325 .id_table = bh1750_id,326 327};328module_i2c_driver(bh1750_driver);329 330MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");331MODULE_DESCRIPTION("ROHM BH1710/BH1715/BH1721/BH1750/BH1751 als driver");332MODULE_LICENSE("GPL v2");333