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Subject[PATCH] iio: light: add support for ROHM BH1710/BH1715/BH1721/BH1750/BH1751 ambient light sensors
Date
Add support for ROHM BH1710/BH1715/BH1721/BH1750/BH1751 ambient light
sensors.

Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>
---
drivers/iio/light/Kconfig | 10 ++
drivers/iio/light/Makefile | 1 +
drivers/iio/light/bh1750.c | 322 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 333 insertions(+)
create mode 100644 drivers/iio/light/bh1750.c

diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
index 5a3237b..9fb79ca 100644
--- a/drivers/iio/light/Kconfig
+++ b/drivers/iio/light/Kconfig
@@ -37,6 +37,16 @@ config APDS9300
To compile this driver as a module, choose M here: the
module will be called apds9300.

+config BH1750
+ tristate "BH1750 ambient light sensor"
+ depends on I2C
+ help
+ Say Y here to build support for the BH1710, BH1715, BH1721,
+ BH1750, BH1751 ambient light sensors.
+
+ To compile this driver as a module, choose M here: the module will
+ be called bh1750.
+
config CM32181
depends on I2C
tristate "CM32181 driver"
diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
index 74656c1..1a13184 100644
--- a/drivers/iio/light/Makefile
+++ b/drivers/iio/light/Makefile
@@ -6,6 +6,7 @@
obj-$(CONFIG_ADJD_S311) += adjd_s311.o
obj-$(CONFIG_AL3320A) += al3320a.o
obj-$(CONFIG_APDS9300) += apds9300.o
+obj-$(CONFIG_BH1750) += bh1750.o
obj-$(CONFIG_CM32181) += cm32181.o
obj-$(CONFIG_CM36651) += cm36651.o
obj-$(CONFIG_GP2AP020A00F) += gp2ap020a00f.o
diff --git a/drivers/iio/light/bh1750.c b/drivers/iio/light/bh1750.c
new file mode 100644
index 0000000..83b5413
--- /dev/null
+++ b/drivers/iio/light/bh1750.c
@@ -0,0 +1,322 @@
+/*
+ * 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_H_RES_MODE 0x10 /* auto-mode for BH1721 */
+#define BH1750_CHANGE_INT_TIME_H_BIT 0x40
+#define BH1750_CHANGE_INT_TIME_L_BIT 0x60
+
+enum {
+ BH1710,
+ BH1715,
+ BH1721,
+ BH1750,
+ BH1751
+};
+
+struct bh1750_chip_info {
+ int id;
+ int mtreg_min;
+ int mtreg_max;
+ int mtreg_default;
+ int mtreg_to_usec;
+ int mtreg_to_scale;
+};
+
+struct bh1750_data {
+ struct i2c_client *client;
+ struct mutex lock;
+ const struct bh1750_chip_info *chip_info;
+ u16 mtreg;
+};
+
+static const struct bh1750_chip_info chip_info_tbl[] = {
+ [BH1710] = { BH1710, 140, 1022, 300, 400, 4000 },
+ [BH1715] = { BH1715, 31, 254, 69, 1740, 17391 },
+ [BH1721] = { BH1721, 140, 1020, 300, 400, 4000 },
+ [BH1750] = { BH1750, 31, 254, 69, 1740, 17391 },
+ [BH1751] = { BH1751, 31, 254, 69, 1740, 17391 }
+};
+
+static int bh1750_change_int_time(struct bh1750_data *data, int usec)
+{
+ int ret, val;
+ u8 low = 0, high = 0;
+ 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;
+
+ switch (chip_info->id) {
+ case BH1710:
+ low = val & 0x001F;
+ high = (val & 0x03E0) >> 5;
+ break;
+ case BH1721:
+ low = val & 0x0010;
+ high = (val & 0x03E0) >> 5;
+ case BH1715:
+ case BH1750:
+ case BH1751:
+ low = val & 0x001F;
+ high = (val & 0x00E0) >> 5;
+ break;
+ }
+
+ ret = i2c_smbus_write_byte(data->client, BH1750_POWER_DOWN);
+ if (ret < 0)
+ return ret;
+
+ ret = i2c_smbus_write_byte(data->client,
+ BH1750_CHANGE_INT_TIME_H_BIT | high);
+ if (ret < 0)
+ return ret;
+
+ ret = i2c_smbus_write_byte(data->client,
+ BH1750_CHANGE_INT_TIME_L_BIT | low);
+ if (ret < 0)
+ return ret;
+
+ data->mtreg = val;
+
+ return i2c_smbus_write_byte(data->client, BH1750_H_RES_MODE);
+}
+
+static int bh1750_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ u16 result;
+ int ret, tmp;
+ unsigned long delay;
+ 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_INTENSITY:
+ delay = chip_info->mtreg_to_usec * data->mtreg;
+ mutex_lock(&data->lock);
+ usleep_range(delay, delay + 20000);
+ ret = i2c_master_recv(data->client,
+ (char *)&result, 2);
+ mutex_unlock(&data->lock);
+ if (ret < 0)
+ return ret;
+
+ *val = swab16(result);
+ 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, inc;
+ 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;
+
+ switch (chip_info->id) {
+ case BH1710:
+ case BH1721:
+ /* All values won't fit into one page, so display every
+ * second one. By doing so step size is increased
+ * from 0.4ms to 0.8ms.*/
+ inc = 2;
+ break;
+ default:
+ inc = 1;
+ break;
+ }
+
+ for (i = chip_info->mtreg_min; i <= chip_info->mtreg_max; i += inc)
+ len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06d ",
+ i * chip_info->mtreg_to_usec);
+
+ 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_INTENSITY,
+ .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 = &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 devm_iio_device_register(&client->dev, indio_dev);
+}
+
+#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)));
+
+ mutex_lock(&data->lock);
+ ret = i2c_smbus_write_byte(data->client, BH1750_POWER_DOWN);
+ mutex_unlock(&data->lock);
+
+ return ret;
+}
+
+static int bh1750_resume(struct device *dev)
+{
+ struct bh1750_data *data =
+ iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
+
+ return i2c_smbus_write_byte(data->client, BH1750_H_RES_MODE);
+}
+
+static SIMPLE_DEV_PM_OPS(bh1750_pm_ops, bh1750_suspend, bh1750_resume);
+#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", BH1715 },
+ { "bh1721", BH1721 },
+ { "bh1750", BH1750 },
+ { "bh1751", BH1751 },
+ { }
+};
+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,
+ .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");
--
2.3.5


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