> This patch adds support to the Industrial IO subsystem > for the Silicon Labs Si701x/2x Relative Humidity and > Temperature Sensors.
the name si701x is problematic; the si7015 for example is supported by the si7005 driver how about calling the driver si7020 and stating that it also supports si7013, si7021 -- the x notation in driver names always leads to touble... the additional features of the si7013 are not supported by the driver > Website: > http://www.silabs.com/products/sensors/humidity-sensors/Pages/si7013-20-21.aspx > > These are i2c devices which measure relative humidity > and temperature and all use the same protocol. The > Si7013 has an additional input with programmable > linearization which is not supported because that's > complicated and I didn't need it. > > Signed-off-by: David Barksdale <dbarksd...@uplogix.com> > > --- > drivers/iio/humidity/Kconfig | 10 +++ > drivers/iio/humidity/Makefile | 1 + > drivers/iio/humidity/si701x.c | 159 > ++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 170 insertions(+) > > diff --git a/drivers/iio/humidity/Kconfig b/drivers/iio/humidity/Kconfig > index e116bd8..ba0ef61 100644 > --- a/drivers/iio/humidity/Kconfig > +++ b/drivers/iio/humidity/Kconfig > @@ -22,4 +22,14 @@ config SI7005 > To compile this driver as a module, choose M here: the module > will be called si7005. > > +config SI701X > + tristate "Si701x/2x Relative Humidity and Temperature Sensors" > + depends on I2C > + help > + Say yes here to build support for the Silicon Labs Si701x/2x Relative > + Humidity and Temperature Sensors. > + > + To compile this driver as a module, choose M here: the module > + will be called si701x. > + > endmenu > diff --git a/drivers/iio/humidity/Makefile b/drivers/iio/humidity/Makefile > index e3f3d94..d2e9645 100644 > --- a/drivers/iio/humidity/Makefile > +++ b/drivers/iio/humidity/Makefile > @@ -4,3 +4,4 @@ > > obj-$(CONFIG_DHT11) += dht11.o > obj-$(CONFIG_SI7005) += si7005.o > +obj-$(CONFIG_SI701X) += si701x.o > diff --git a/drivers/iio/humidity/si701x.c b/drivers/iio/humidity/si701x.c > new file mode 100644 > index 0000000..1a2ee22 > --- /dev/null > +++ b/drivers/iio/humidity/si701x.c > @@ -0,0 +1,159 @@ > +/* > + * si701x.c - Silicon Labs Si701x/2x Relative Humidity and Temperature > Sensors > + * Copyright (c) 2013,2014 Uplogix, Inc. > + * David Barksdale <dbarksd...@uplogix.com> > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms and conditions of the GNU General Public License, > + * version 2, as published by the Free Software Foundation. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + */ > + > +/* > + * The Silicon Labs Si701x/2x Relative Humidity and Temperature Sensors > + * are i2c devices which have an identical programming interface for > + * measuring relative humidity and temperature. The Si7013 has an additional > + * temperature input which this driver does not support. > + * > + * Data Sheets: > + * Si7013: > http://www.silabs.com/Support%20Documents/TechnicalDocs/Si7013.pdf > + * Si7020: > http://www.silabs.com/Support%20Documents/TechnicalDocs/Si7020.pdf > + * Si7021: > http://www.silabs.com/Support%20Documents/TechnicalDocs/Si7021.pdf > + */ > + > +#include <linux/i2c.h> > +#include <linux/module.h> > +#include <linux/slab.h> > +#include <linux/sysfs.h> > + > +#include <linux/iio/iio.h> > +#include <linux/iio/sysfs.h> > + > +enum { > + /* Measure Relative Humidity, Hold Master Mode */ > + SI701XCMD_RH_HOLD = 0xE5, > + /* Measure Temperature, Hold Master Mode */ > + SI701XCMD_TEMP_HOLD = 0xE3, > +}; > + > +struct si701x_data { > + struct i2c_client *client; > + struct mutex lock; > +}; > + > +static int si701x_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, int *val, > + int *val2, long mask) > +{ > + struct si701x_data *data = iio_priv(indio_dev); > + int ret; > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: > + mutex_lock(&data->lock); is the locking needed? what is protected? > + ret = i2c_smbus_read_word_data(data->client, > + chan->type == IIO_TEMP ? > + SI701XCMD_TEMP_HOLD : > + SI701XCMD_RH_HOLD); > + mutex_unlock(&data->lock); > + if (ret < 0) > + return ret; > + *val = ret; > + return IIO_VAL_INT; > + case IIO_CHAN_INFO_SCALE: > + if (chan->type == IIO_TEMP) { > + *val = 175.72 * 1000; floating-point constants in kernel space makes me nervous > + *val2 = 65536; could set val2 once after the if > + } else { > + *val = 125 * 1000; > + *val2 = 65536; > + } > + return IIO_VAL_FRACTIONAL; > + case IIO_CHAN_INFO_OFFSET: > + if (chan->type == IIO_TEMP) > + *val = -46.85 * 65536 / 175.72; > + else > + *val = -6 * 65536 / 125; > + return IIO_VAL_INT; > + default: > + break; > + } > + > + return -EINVAL; > +} > + > +static const struct iio_chan_spec si701x_channels[] = { > + { > + .type = IIO_HUMIDITYRELATIVE, > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | > + BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET), > + }, > + { > + .type = IIO_TEMP, > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | > + BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET), > + } > +}; > + > +static const struct iio_info si701x_info = { > + .read_raw = si701x_read_raw, > + .driver_module = THIS_MODULE, > +}; > + > +static int si701x_probe(struct i2c_client *client, > + const struct i2c_device_id *id) > +{ > + struct iio_dev *dev; > + struct si701x_data *data; > + > + if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA)) > + return -ENODEV; > + > + dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); > + if (!dev) > + return -ENOMEM; > + > + data = iio_priv(dev); > + i2c_set_clientdata(client, dev); > + data->client = client; > + mutex_init(&data->lock); > + > + dev->dev.parent = &client->dev; > + dev->name = dev_name(&client->dev); > + dev->modes = INDIO_DIRECT_MODE; > + dev->info = &si701x_info; > + dev->channels = si701x_channels; > + dev->num_channels = ARRAY_SIZE(si701x_channels); > + > + return devm_iio_device_register(&client->dev, dev); > +} > + > +static const unsigned short si701x_address_list[] = { > + 0x40, the alternate address is 0x41 > + I2C_CLIENT_END > +}; > + > +static const struct i2c_device_id si701x_id[] = { > + { "si701x", 0 }, > + { } > +}; > +MODULE_DEVICE_TABLE(i2c, si701x_id); > + > +static struct i2c_driver si701x_driver = { > + .class = I2C_CLASS_HWMON, > + .driver.name = "si701x", > + .probe = si701x_probe, > + .address_list = si701x_address_list, > + .id_table = si701x_id, address_list and I2C_CLASS_HWMON -- what for? if doing auto-probing, I'd check the chip's ID > +}; > + > +module_i2c_driver(si701x_driver); > +MODULE_DESCRIPTION("Silicon Labs Si701x/2x " > + "Relative Humidity and Temperature Sensors"); > +MODULE_AUTHOR("David Barksdale <dbarksd...@uplogix.com>"); > +MODULE_LICENSE("GPL"); > + > -- Peter Meerwald +43-664-2444418 (mobile) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
