--- /dev/null
+/*
+ * ROHM BH1710/BH1715/BH1721/BH1750/BH1751 ambient light sensor driver
+ *
+ * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Data sheets:
+ * http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1710fvc-e.pdf
+ * http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1715fvc-e.pdf
+ * http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1721fvc-e.pdf
+ * http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1750fvi-e.pdf
+ * http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1751fvi-e.pdf
+ *
+ * 7-bit I2C slave addresses:
+ * 0x23 (ADDR pin low)
+ * 0x5C (ADDR pin high)
+ *
+ */
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/module.h>
+
+#define BH1750_POWER_DOWN 0x00
+#define BH1750_ONE_TIME_H_RES_MODE 0x20 /* auto-mode for BH1721 */
+#define BH1750_CHANGE_INT_TIME_H_BIT 0x40
+#define BH1750_CHANGE_INT_TIME_L_BIT 0x60
+
+enum {
+ BH1710,
+ BH1721,
+ BH1750,
+};
+
+struct bh1750_chip_info;
+struct bh1750_data {
+ struct i2c_client *client;
+ struct mutex lock;
+ const struct bh1750_chip_info *chip_info;
+ u16 mtreg;
+};
+
+struct bh1750_chip_info {
+ u16 mtreg_min;
+ u16 mtreg_max;
+ u16 mtreg_default;
+ int mtreg_to_usec;
+ int mtreg_to_scale;
+
+ /*
+ * For BH1710/BH1721 all possible integration time values won't fit
+ * into one page so displaying is limited to every second one.
+ * Note, that user can still write proper values which were not
+ * listed.
+ */
+ int inc;
+
+ u16 int_time_low_mask;
+ u16 int_time_high_mask;
+}
+
+static const bh1750_chip_info_tbl[] = {
+ [BH1710] = { 140, 1022, 300, 400, 250000000, 2, 0x001F, 0x03E0 },
+ [BH1721] = { 140, 1020, 300, 400, 250000000, 2, 0x0010, 0x03E0 },
+ [BH1750] = { 31, 254, 69, 1740, 57500000, 1, 0x001F, 0x00E0 },
+};
+
+static int bh1750_change_int_time(struct bh1750_data *data, int usec)
+{
+ int ret;
+ u16 val;
+ u8 regval;
+ const struct bh1750_chip_info *chip_info = data->chip_info;
+
+ if ((usec % chip_info->mtreg_to_usec) != 0)
+ return -EINVAL;
+
+ val = usec / chip_info->mtreg_to_usec;
+ if (val < chip_info->mtreg_min || val > chip_info->mtreg_max)
+ return -EINVAL;
+
+ ret = i2c_smbus_write_byte(data->client, BH1750_POWER_DOWN);
+ if (ret < 0)
+ return ret;
+
+ regval = (val & chip_info->int_time_high_mask) >> 5;
+ ret = i2c_smbus_write_byte(data->client,
+ BH1750_CHANGE_INT_TIME_H_BIT | regval);
+ if (ret < 0)
+ return ret;
+
+ regval = val & chip_info->int_time_low_mask;
+ ret = i2c_smbus_write_byte(data->client,
+ BH1750_CHANGE_INT_TIME_L_BIT | regval);
+ if (ret < 0)
+ return ret;
+
+ data->mtreg = val;
+
+ return 0;
+}
+
+static int bh1750_read(struct bh1750_data *data, int *val)
+{
+ int ret;
+ __be16 result;
+ const struct bh1750_chip_info *chip_info = data->chip_info;
+ unsigned long delay = chip_info->mtreg_to_usec * data->mtreg;
+
+ /*
+ * BH1721 will enter continuous mode on receiving this command.
+ * Note, that this eliminates need for bh1750_resume().
+ */
+ ret = i2c_smbus_write_byte(data->client, BH1750_ONE_TIME_H_RES_MODE);
+ if (ret < 0)
+ return ret;
+
+ usleep_range(delay + 15000, delay + 40000);
+
+ ret = i2c_master_recv(data->client, (char *)&result, 2);
+ if (ret < 0)
+ return ret;
+
+ *val = be16_to_cpu(result);
+
+ return 0;
+}
+
+static int bh1750_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ int ret, tmp;
+ struct bh1750_data *data = iio_priv(indio_dev);
+ const struct bh1750_chip_info *chip_info = data->chip_info;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ switch (chan->type) {
+ case IIO_LIGHT:
+ mutex_lock(&data->lock);
+ ret = bh1750_read(data, val);
+ mutex_unlock(&data->lock);
+ if (ret < 0)
+ return ret;
+
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+ case IIO_CHAN_INFO_SCALE:
+ tmp = chip_info->mtreg_to_scale / data->mtreg;
+ *val = tmp / 1000000;
+ *val2 = tmp % 1000000;
+ return IIO_VAL_INT_PLUS_MICRO;
+ case IIO_CHAN_INFO_INT_TIME:
+ *val = 0;
+ *val2 = chip_info->mtreg_to_usec * data->mtreg;
+ return IIO_VAL_INT_PLUS_MICRO;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int bh1750_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ int ret;
+ struct bh1750_data *data = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_INT_TIME:
+ if (val != 0)
+ return -EINVAL;
+
+ mutex_lock(&data->lock);
+ ret = bh1750_change_int_time(data, val2);
+ mutex_unlock(&data->lock);
+ return ret;
+ default:
+ return -EINVAL;
+ }
+}
+
+static ssize_t bh1750_show_int_time_available(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ int i;
+ size_t len = 0;
+ struct bh1750_data *data = iio_priv(dev_to_iio_dev(dev));
+ const struct bh1750_chip_info *chip_info = data->chip_info;
+
+ for (i = chip_info->mtreg_min; i <= chip_info->mtreg_max; i += chip_info->inc)
+ len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06d ",
+ chip_info->mtreg_to_usec * i);
+
+ buf[len - 1] = '\n';
+
+ return len;
+}
+
+static IIO_DEV_ATTR_INT_TIME_AVAIL(bh1750_show_int_time_available);
+
+static struct attribute *bh1750_attributes[] = {
+ &iio_dev_attr_integration_time_available.dev_attr.attr,
+ NULL,
+};
+
+static struct attribute_group bh1750_attribute_group = {
+ .attrs = bh1750_attributes,
+};
+
+static const struct iio_info bh1750_info = {
+ .driver_module = THIS_MODULE,
+ .attrs = &bh1750_attribute_group,
+ .read_raw = bh1750_read_raw,
+ .write_raw = bh1750_write_raw,
+};
+
+static const struct iio_chan_spec bh1750_channels[] = {
+ {
+ .type = IIO_LIGHT,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_INT_TIME)
+ }
+};
+
+static int bh1750_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ int ret, usec;
+ struct bh1750_data *data;
+ struct iio_dev *indio_dev;
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
+ I2C_FUNC_SMBUS_WRITE_BYTE))
+ return -ENODEV;
+
+ 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->client = client;
+ data->chip_info = &bh1750_chip_info_tbl[id->driver_data];
+
+ usec = data->chip_info->mtreg_to_usec * data->chip_info->mtreg_default;
+ ret = bh1750_change_int_time(data, usec);
+ if (ret < 0)
+ return ret;
+
+ mutex_init(&data->lock);
+ indio_dev->dev.parent = &client->dev;
+ indio_dev->info = &bh1750_info;
+ indio_dev->name = id->name;
+ indio_dev->channels = bh1750_channels;
+ indio_dev->num_channels = ARRAY_SIZE(bh1750_channels);
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ return iio_device_register(indio_dev);
+}
+
+static int bh1750_remove(struct i2c_client *client)
+{
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct bh1750_data *data = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+
+ mutex_lock(&data->lock);
+ i2c_smbus_write_byte(client, BH1750_POWER_DOWN);
+ mutex_unlock(&data->lock);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int bh1750_suspend(struct device *dev)
+{
+ int ret;
+ struct bh1750_data *data =
+ iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
+
+ /*
+ * This is mainly for BH1721 which doesn't enter power down
+ * mode automatically.
+ */
+ mutex_lock(&data->lock);
+ ret = i2c_smbus_write_byte(data->client, BH1750_POWER_DOWN);
+ mutex_unlock(&data->lock);
+
+ return ret;
+}
+
+static SIMPLE_DEV_PM_OPS(bh1750_pm_ops, bh1750_suspend, NULL);
+#define BH1750_PM_OPS (&bh1750_pm_ops)
+#else
+#define BH1750_PM_OPS NULL
+#endif
+
+static const struct i2c_device_id bh1750_id[] = {
+ { "bh1710", BH1710 },
+ { "bh1715", BH1750 },
+ { "bh1721", BH1721 },
+ { "bh1750", BH1750 },
+ { "bh1751", BH1750 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, bh1750_id);
+
+static struct i2c_driver bh1750_driver = {
+ .driver = {
+ .name = "bh1750",
+ .owner = THIS_MODULE,
+ .pm = BH1750_PM_OPS,
+ },
+ .probe = bh1750_probe,
+ .remove = bh1750_remove,
+ .id_table = bh1750_id,
+
+};
+module_i2c_driver(bh1750_driver);
+
+MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
+MODULE_DESCRIPTION("ROHM BH1710/BH1715/BH1721/BH1750/BH1751 als driver");
+MODULE_LICENSE("GPL v2");
projects / openwrt / staging / blogic.git / commitdiff