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213 lines
4.9 KiB
213 lines
4.9 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* veml6070.c - Support for Vishay VEML6070 UV A light sensor |
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* |
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* Copyright 2016 Peter Meerwald-Stadler <[email protected]> |
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* |
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* IIO driver for VEML6070 (7-bit I2C slave addresses 0x38 and 0x39) |
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* |
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* TODO: integration time, ACK signal |
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*/ |
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#include <linux/module.h> |
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#include <linux/i2c.h> |
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#include <linux/mutex.h> |
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#include <linux/err.h> |
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#include <linux/delay.h> |
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#include <linux/iio/iio.h> |
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#include <linux/iio/sysfs.h> |
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#define VEML6070_DRV_NAME "veml6070" |
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#define VEML6070_ADDR_CONFIG_DATA_MSB 0x38 /* read: MSB data, write: config */ |
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#define VEML6070_ADDR_DATA_LSB 0x39 /* LSB data */ |
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#define VEML6070_COMMAND_ACK BIT(5) /* raise interrupt when over threshold */ |
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#define VEML6070_COMMAND_IT GENMASK(3, 2) /* bit mask integration time */ |
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#define VEML6070_COMMAND_RSRVD BIT(1) /* reserved, set to 1 */ |
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#define VEML6070_COMMAND_SD BIT(0) /* shutdown mode when set */ |
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#define VEML6070_IT_10 0x04 /* integration time 1x */ |
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struct veml6070_data { |
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struct i2c_client *client1; |
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struct i2c_client *client2; |
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u8 config; |
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struct mutex lock; |
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}; |
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static int veml6070_read(struct veml6070_data *data) |
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{ |
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int ret; |
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u8 msb, lsb; |
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mutex_lock(&data->lock); |
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/* disable shutdown */ |
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ret = i2c_smbus_write_byte(data->client1, |
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data->config & ~VEML6070_COMMAND_SD); |
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if (ret < 0) |
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goto out; |
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msleep(125 + 10); /* measurement takes up to 125 ms for IT 1x */ |
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ret = i2c_smbus_read_byte(data->client2); /* read MSB, address 0x39 */ |
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if (ret < 0) |
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goto out; |
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msb = ret; |
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ret = i2c_smbus_read_byte(data->client1); /* read LSB, address 0x38 */ |
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if (ret < 0) |
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goto out; |
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lsb = ret; |
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/* shutdown again */ |
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ret = i2c_smbus_write_byte(data->client1, data->config); |
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if (ret < 0) |
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goto out; |
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ret = (msb << 8) | lsb; |
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out: |
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mutex_unlock(&data->lock); |
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return ret; |
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} |
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static const struct iio_chan_spec veml6070_channels[] = { |
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{ |
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.type = IIO_INTENSITY, |
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.modified = 1, |
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.channel2 = IIO_MOD_LIGHT_UV, |
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), |
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}, |
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{ |
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.type = IIO_UVINDEX, |
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.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), |
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} |
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}; |
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static int veml6070_to_uv_index(unsigned val) |
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{ |
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/* |
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* conversion of raw UV intensity values to UV index depends on |
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* integration time (IT) and value of the resistor connected to |
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* the RSET pin (default: 270 KOhm) |
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*/ |
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unsigned uvi[11] = { |
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187, 373, 560, /* low */ |
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746, 933, 1120, /* moderate */ |
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1308, 1494, /* high */ |
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1681, 1868, 2054}; /* very high */ |
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int i; |
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for (i = 0; i < ARRAY_SIZE(uvi); i++) |
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if (val <= uvi[i]) |
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return i; |
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return 11; /* extreme */ |
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} |
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static int veml6070_read_raw(struct iio_dev *indio_dev, |
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struct iio_chan_spec const *chan, |
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int *val, int *val2, long mask) |
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{ |
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struct veml6070_data *data = iio_priv(indio_dev); |
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int ret; |
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switch (mask) { |
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case IIO_CHAN_INFO_RAW: |
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case IIO_CHAN_INFO_PROCESSED: |
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ret = veml6070_read(data); |
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if (ret < 0) |
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return ret; |
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if (mask == IIO_CHAN_INFO_PROCESSED) |
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*val = veml6070_to_uv_index(ret); |
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else |
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*val = ret; |
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return IIO_VAL_INT; |
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default: |
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return -EINVAL; |
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} |
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} |
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static const struct iio_info veml6070_info = { |
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.read_raw = veml6070_read_raw, |
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}; |
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static int veml6070_probe(struct i2c_client *client, |
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const struct i2c_device_id *id) |
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{ |
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struct veml6070_data *data; |
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struct iio_dev *indio_dev; |
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int ret; |
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indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); |
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if (!indio_dev) |
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return -ENOMEM; |
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data = iio_priv(indio_dev); |
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i2c_set_clientdata(client, indio_dev); |
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data->client1 = client; |
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mutex_init(&data->lock); |
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indio_dev->info = &veml6070_info; |
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indio_dev->channels = veml6070_channels; |
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indio_dev->num_channels = ARRAY_SIZE(veml6070_channels); |
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indio_dev->name = VEML6070_DRV_NAME; |
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indio_dev->modes = INDIO_DIRECT_MODE; |
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data->client2 = i2c_new_dummy_device(client->adapter, VEML6070_ADDR_DATA_LSB); |
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if (IS_ERR(data->client2)) { |
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dev_err(&client->dev, "i2c device for second chip address failed\n"); |
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return PTR_ERR(data->client2); |
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} |
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data->config = VEML6070_IT_10 | VEML6070_COMMAND_RSRVD | |
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VEML6070_COMMAND_SD; |
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ret = i2c_smbus_write_byte(data->client1, data->config); |
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if (ret < 0) |
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goto fail; |
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ret = iio_device_register(indio_dev); |
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if (ret < 0) |
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goto fail; |
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return ret; |
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fail: |
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i2c_unregister_device(data->client2); |
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return ret; |
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} |
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static int veml6070_remove(struct i2c_client *client) |
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{ |
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struct iio_dev *indio_dev = i2c_get_clientdata(client); |
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struct veml6070_data *data = iio_priv(indio_dev); |
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iio_device_unregister(indio_dev); |
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i2c_unregister_device(data->client2); |
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return 0; |
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} |
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static const struct i2c_device_id veml6070_id[] = { |
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{ "veml6070", 0 }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(i2c, veml6070_id); |
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static struct i2c_driver veml6070_driver = { |
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.driver = { |
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.name = VEML6070_DRV_NAME, |
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}, |
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.probe = veml6070_probe, |
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.remove = veml6070_remove, |
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.id_table = veml6070_id, |
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}; |
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module_i2c_driver(veml6070_driver); |
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MODULE_AUTHOR("Peter Meerwald-Stadler <[email protected]>"); |
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MODULE_DESCRIPTION("Vishay VEML6070 UV A light sensor driver"); |
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MODULE_LICENSE("GPL");
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