1 files changed, 218 insertions, 0 deletions

diff --git a/drivers/iio/light/veml6070.c b/drivers/iio/light/veml6070.c
new file mode 100644
index 000000000000..bc1c4cb782cd
--- /dev/null
+++ b/drivers/iio/light/veml6070.c
@@ -0,0 +1,218 @@
+/*
+ * 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");