cregit-Linux how code gets into the kernel

Release 4.7 drivers/iio/light/veml6070.c

/*
 * veml6070.c - Support for Vishay VEML6070 UV A light sensor
 *
 * Copyright 2016 Peter Meerwald-Stadler <pmeerw@pmeerw.net>
 *
 * This file is subject to the terms and conditions of version 2 of
 * the GNU General Public License.  See the file COPYING in the main
 * directory of this archive for more details.
 *
 * IIO driver for VEML6070 (7-bit I2C slave addresses 0x38 and 0x39)
 *
 * TODO: integration time, ACK signal
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/mutex.h>
#include <linux/err.h>
#include <linux/delay.h>

#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>


#define VEML6070_DRV_NAME "veml6070"


#define VEML6070_ADDR_CONFIG_DATA_MSB 0x38 
/* read: MSB data, write: config */

#define VEML6070_ADDR_DATA_LSB	0x39 
/* LSB data */


#define VEML6070_COMMAND_ACK	BIT(5) 
/* raise interrupt when over threshold */

#define VEML6070_COMMAND_IT	GENMASK(3, 2) 
/* bit mask integration time */

#define VEML6070_COMMAND_RSRVD	BIT(1) 
/* reserved, set to 1 */

#define VEML6070_COMMAND_SD	BIT(0) 
/* shutdown mode when set */


#define VEML6070_IT_10	0x04 
/* integration time 1x */


struct veml6070_data {
	
struct i2c_client *client1;
	
struct i2c_client *client2;
	
u8 config;
	
struct mutex lock;
};


static int veml6070_read(struct veml6070_data *data) { int ret; u8 msb, lsb; mutex_lock(&data->lock); /* disable shutdown */ ret = i2c_smbus_write_byte(data->client1, data->config & ~VEML6070_COMMAND_SD); if (ret < 0) goto out; msleep(125 + 10); /* measurement takes up to 125 ms for IT 1x */ ret = i2c_smbus_read_byte(data->client2); /* read MSB, address 0x39 */ if (ret < 0) goto out; msb = ret; ret = i2c_smbus_read_byte(data->client1); /* read LSB, address 0x38 */ if (ret < 0) goto out; lsb = ret; /* shutdown again */ ret = i2c_smbus_write_byte(data->client1, data->config); if (ret < 0) goto out; ret = (msb << 8) | lsb; out: mutex_unlock(&data->lock); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
peter meerwaldpeter meerwald153100.00%1100.00%
Total153100.00%1100.00%

static const struct iio_chan_spec veml6070_channels[] = { { .type = IIO_INTENSITY, .modified = 1, .channel2 = IIO_MOD_LIGHT_UV, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), }, { .type = IIO_UVINDEX, .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), } };
static int veml6070_to_uv_index(unsigned val) { /* * conversion of raw UV intensity values to UV index depends on * integration time (IT) and value of the resistor connected to * the RSET pin (default: 270 KOhm) */ unsigned uvi[11] = { 187, 373, 560, /* low */ 746, 933, 1120, /* moderate */ 1308, 1494, /* high */ 1681, 1868, 2054}; /* very high */ int i; for (i = 0; i < ARRAY_SIZE(uvi); i++) if (val <= uvi[i]) return i; return 11; /* extreme */ }

Contributors

PersonTokensPropCommitsCommitProp
peter meerwaldpeter meerwald79100.00%1100.00%
Total79100.00%1100.00%


static int veml6070_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { struct veml6070_data *data = iio_priv(indio_dev); int ret; switch (mask) { case IIO_CHAN_INFO_RAW: case IIO_CHAN_INFO_PROCESSED: ret = veml6070_read(data); if (ret < 0) return ret; if (mask == IIO_CHAN_INFO_PROCESSED) *val = veml6070_to_uv_index(ret); else *val = ret; return IIO_VAL_INT; default: return -EINVAL; } }

Contributors

PersonTokensPropCommitsCommitProp
peter meerwaldpeter meerwald97100.00%1100.00%
Total97100.00%1100.00%

static const struct iio_info veml6070_info = { .read_raw = veml6070_read_raw, .driver_module = THIS_MODULE, };
static int veml6070_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct veml6070_data *data; struct iio_dev *indio_dev; int ret; indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); if (!indio_dev) return -ENOMEM; data = iio_priv(indio_dev); i2c_set_clientdata(client, indio_dev); data->client1 = client; mutex_init(&data->lock); indio_dev->dev.parent = &client->dev; indio_dev->info = &veml6070_info; indio_dev->channels = veml6070_channels; indio_dev->num_channels = ARRAY_SIZE(veml6070_channels); indio_dev->name = VEML6070_DRV_NAME; indio_dev->modes = INDIO_DIRECT_MODE; data->client2 = i2c_new_dummy(client->adapter, VEML6070_ADDR_DATA_LSB); if (!data->client2) { dev_err(&client->dev, "i2c device for second chip address failed\n"); return -ENODEV; } data->config = VEML6070_IT_10 | VEML6070_COMMAND_RSRVD | VEML6070_COMMAND_SD; ret = i2c_smbus_write_byte(data->client1, data->config); if (ret < 0) goto fail; ret = iio_device_register(indio_dev); if (ret < 0) goto fail; return ret; fail: i2c_unregister_device(data->client2); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
peter meerwaldpeter meerwald227100.00%1100.00%
Total227100.00%1100.00%


static int veml6070_remove(struct i2c_client *client) { struct iio_dev *indio_dev = i2c_get_clientdata(client); struct veml6070_data *data = iio_priv(indio_dev); iio_device_unregister(indio_dev); i2c_unregister_device(data->client2); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
peter meerwaldpeter meerwald46100.00%1100.00%
Total46100.00%1100.00%

static const struct i2c_device_id veml6070_id[] = { { "veml6070", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, veml6070_id); static struct i2c_driver veml6070_driver = { .driver = { .name = VEML6070_DRV_NAME, }, .probe = veml6070_probe, .remove = veml6070_remove, .id_table = veml6070_id, }; module_i2c_driver(veml6070_driver); MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>"); MODULE_DESCRIPTION("Vishay VEML6070 UV A light sensor driver"); MODULE_LICENSE("GPL");

Overall Contributors

PersonTokensPropCommitsCommitProp
peter meerwaldpeter meerwald828100.00%1100.00%
Total828100.00%1100.00%
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
{% endraw %}