--- /dev/null
+/*
+ * 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;
+}
+
+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 */
+}
+
+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;
+ }
+}
+
+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;
+}
+
+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;
+}
+
+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");
projects / nvme.git / commitdiff