211 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * veml6070.c - Support for Vishay VEML6070 UV A light sensor4 *5 * Copyright 2016 Peter Meerwald-Stadler <pmeerw@pmeerw.net>6 *7 * IIO driver for VEML6070 (7-bit I2C slave addresses 0x38 and 0x39)8 *9 * TODO: integration time, ACK signal10 */11 12#include <linux/module.h>13#include <linux/i2c.h>14#include <linux/mutex.h>15#include <linux/err.h>16#include <linux/delay.h>17 18#include <linux/iio/iio.h>19#include <linux/iio/sysfs.h>20 21#define VEML6070_DRV_NAME "veml6070"22 23#define VEML6070_ADDR_CONFIG_DATA_MSB 0x38 /* read: MSB data, write: config */24#define VEML6070_ADDR_DATA_LSB 0x39 /* LSB data */25 26#define VEML6070_COMMAND_ACK BIT(5) /* raise interrupt when over threshold */27#define VEML6070_COMMAND_IT GENMASK(3, 2) /* bit mask integration time */28#define VEML6070_COMMAND_RSRVD BIT(1) /* reserved, set to 1 */29#define VEML6070_COMMAND_SD BIT(0) /* shutdown mode when set */30 31#define VEML6070_IT_10 0x04 /* integration time 1x */32 33struct veml6070_data {34 struct i2c_client *client1;35 struct i2c_client *client2;36 u8 config;37 struct mutex lock;38};39 40static int veml6070_read(struct veml6070_data *data)41{42 int ret;43 u8 msb, lsb;44 45 mutex_lock(&data->lock);46 47 /* disable shutdown */48 ret = i2c_smbus_write_byte(data->client1,49 data->config & ~VEML6070_COMMAND_SD);50 if (ret < 0)51 goto out;52 53 msleep(125 + 10); /* measurement takes up to 125 ms for IT 1x */54 55 ret = i2c_smbus_read_byte(data->client2); /* read MSB, address 0x39 */56 if (ret < 0)57 goto out;58 msb = ret;59 60 ret = i2c_smbus_read_byte(data->client1); /* read LSB, address 0x38 */61 if (ret < 0)62 goto out;63 lsb = ret;64 65 /* shutdown again */66 ret = i2c_smbus_write_byte(data->client1, data->config);67 if (ret < 0)68 goto out;69 70 ret = (msb << 8) | lsb;71 72out:73 mutex_unlock(&data->lock);74 return ret;75}76 77static const struct iio_chan_spec veml6070_channels[] = {78 {79 .type = IIO_INTENSITY,80 .modified = 1,81 .channel2 = IIO_MOD_LIGHT_UV,82 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),83 },84 {85 .type = IIO_UVINDEX,86 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),87 }88};89 90static int veml6070_to_uv_index(unsigned val)91{92 /*93 * conversion of raw UV intensity values to UV index depends on94 * integration time (IT) and value of the resistor connected to95 * the RSET pin (default: 270 KOhm)96 */97 unsigned uvi[11] = {98 187, 373, 560, /* low */99 746, 933, 1120, /* moderate */100 1308, 1494, /* high */101 1681, 1868, 2054}; /* very high */102 int i;103 104 for (i = 0; i < ARRAY_SIZE(uvi); i++)105 if (val <= uvi[i])106 return i;107 108 return 11; /* extreme */109}110 111static int veml6070_read_raw(struct iio_dev *indio_dev,112 struct iio_chan_spec const *chan,113 int *val, int *val2, long mask)114{115 struct veml6070_data *data = iio_priv(indio_dev);116 int ret;117 118 switch (mask) {119 case IIO_CHAN_INFO_RAW:120 case IIO_CHAN_INFO_PROCESSED:121 ret = veml6070_read(data);122 if (ret < 0)123 return ret;124 if (mask == IIO_CHAN_INFO_PROCESSED)125 *val = veml6070_to_uv_index(ret);126 else127 *val = ret;128 return IIO_VAL_INT;129 default:130 return -EINVAL;131 }132}133 134static const struct iio_info veml6070_info = {135 .read_raw = veml6070_read_raw,136};137 138static int veml6070_probe(struct i2c_client *client)139{140 struct veml6070_data *data;141 struct iio_dev *indio_dev;142 int ret;143 144 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));145 if (!indio_dev)146 return -ENOMEM;147 148 data = iio_priv(indio_dev);149 i2c_set_clientdata(client, indio_dev);150 data->client1 = client;151 mutex_init(&data->lock);152 153 indio_dev->info = &veml6070_info;154 indio_dev->channels = veml6070_channels;155 indio_dev->num_channels = ARRAY_SIZE(veml6070_channels);156 indio_dev->name = VEML6070_DRV_NAME;157 indio_dev->modes = INDIO_DIRECT_MODE;158 159 data->client2 = i2c_new_dummy_device(client->adapter, VEML6070_ADDR_DATA_LSB);160 if (IS_ERR(data->client2)) {161 dev_err(&client->dev, "i2c device for second chip address failed\n");162 return PTR_ERR(data->client2);163 }164 165 data->config = VEML6070_IT_10 | VEML6070_COMMAND_RSRVD |166 VEML6070_COMMAND_SD;167 ret = i2c_smbus_write_byte(data->client1, data->config);168 if (ret < 0)169 goto fail;170 171 ret = iio_device_register(indio_dev);172 if (ret < 0)173 goto fail;174 175 return ret;176 177fail:178 i2c_unregister_device(data->client2);179 return ret;180}181 182static void veml6070_remove(struct i2c_client *client)183{184 struct iio_dev *indio_dev = i2c_get_clientdata(client);185 struct veml6070_data *data = iio_priv(indio_dev);186 187 iio_device_unregister(indio_dev);188 i2c_unregister_device(data->client2);189}190 191static const struct i2c_device_id veml6070_id[] = {192 { "veml6070" },193 { }194};195MODULE_DEVICE_TABLE(i2c, veml6070_id);196 197static struct i2c_driver veml6070_driver = {198 .driver = {199 .name = VEML6070_DRV_NAME,200 },201 .probe = veml6070_probe,202 .remove = veml6070_remove,203 .id_table = veml6070_id,204};205 206module_i2c_driver(veml6070_driver);207 208MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>");209MODULE_DESCRIPTION("Vishay VEML6070 UV A light sensor driver");210MODULE_LICENSE("GPL");211