Re: [PATCH v4 4/7] Add htu21 meas-spec driver support

[Jonathan Cameron <jic23@kernel.org>]

On 01/10/15 15:13, Ludovic Tancerel wrote:
> Support for HTU21 temperature & humidity sensor
> 
> Signed-off-by: Ludovic Tancerel <ludovic.tancerel@maplehightech.com>
Applied.  A bit of fuzz due to other drivers having gone in recently
plus a bit of space to tab conversion for the documentation file.

Thanks,
Jonathan
> ---
>  Documentation/ABI/testing/sysfs-bus-iio |  10 ++
>  drivers/iio/humidity/Kconfig            |  11 ++
>  drivers/iio/humidity/Makefile           |   1 +
>  drivers/iio/humidity/htu21.c            | 226 ++++++++++++++++++++++++++++++++
>  4 files changed, 248 insertions(+)
>  create mode 100644 drivers/iio/humidity/htu21.c
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
> index 70c9b1a..aac134a 100644
> --- a/Documentation/ABI/testing/sysfs-bus-iio
> +++ b/Documentation/ABI/testing/sysfs-bus-iio
> @@ -1461,3 +1461,13 @@ Description:
>  		measurements and return the average value as output data. Each
>  		value resulted from <type>[_name]_oversampling_ratio measurements
>  		is considered as one sample for <type>[_name]_sampling_frequency.
> +
> +What:           /sys/bus/iio/devices/iio:deviceX/heater_enable
> +KernelVersion:  4.1.0
> +Contact:        linux-iio@vger.kernel.org
> +Description:
> +                A '1' (enable) or '0' (disable) specifying the enable
> +		of heater function. Same reading values apply
> +		This ABI is especially applicable for humidity sensors
> +		to heatup the device and get rid of any condensation
> +		in some humidity environment
> diff --git a/drivers/iio/humidity/Kconfig b/drivers/iio/humidity/Kconfig
> index 688c0d1..3fab60c 100644
> --- a/drivers/iio/humidity/Kconfig
> +++ b/drivers/iio/humidity/Kconfig
> @@ -12,6 +12,17 @@ config DHT11
>  	  Other sensors should work as well as long as they speak the
>  	  same protocol.
>  
> +config HTU21
> +	tristate "Measurement Specialties HTU21 humidity & temperature sensor"
> +	depends on I2C
> +        select IIO_MS_SENSORS_I2C
> +	help
> +	  If you say yes here you get support for the Measurement Specialties
> +	  HTU21 humidity and temperature sensor.
> +
> +	  This driver can also be built as a module. If so, the module will
> +	  be called htu21.
> +
>  config SI7005
>  	tristate "SI7005 relative humidity and temperature sensor"
>  	depends on I2C
> diff --git a/drivers/iio/humidity/Makefile b/drivers/iio/humidity/Makefile
> index 86e2d26..826b1d5 100644
> --- a/drivers/iio/humidity/Makefile
> +++ b/drivers/iio/humidity/Makefile
> @@ -3,5 +3,6 @@
>  #
>  
>  obj-$(CONFIG_DHT11) += dht11.o
> +obj-$(CONFIG_HTU21) += htu21.o
>  obj-$(CONFIG_SI7005) += si7005.o
>  obj-$(CONFIG_SI7020) += si7020.o
> diff --git a/drivers/iio/humidity/htu21.c b/drivers/iio/humidity/htu21.c
> new file mode 100644
> index 0000000..4406b61
> --- /dev/null
> +++ b/drivers/iio/humidity/htu21.c
> @@ -0,0 +1,226 @@
> +/*
> + * htu21.c - Support for Measurement-Specialties
> + *           htu21 temperature & humidity sensor
> + *
> + * Copyright (c) 2014 Measurement-Specialties
> + *
> + * Licensed under the GPL-2.
> + *
> + * (7-bit I2C slave address 0x40)
> + *
> + * Datasheet:
> + *  http://www.meas-spec.com/downloads/HTU21D.pdf
> + */
> +
> +#include <linux/init.h>
> +#include <linux/device.h>
> +#include <linux/kernel.h>
> +#include <linux/stat.h>
> +#include <linux/module.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +
> +#include "../common/ms_sensors/ms_sensors_i2c.h"
> +
> +#define HTU21_RESET				0xFE
> +
> +static const int htu21_samp_freq[4] = { 20, 40, 70, 120 };
> +/* String copy of the above const for readability purpose */
> +static const char htu21_show_samp_freq[] = "20 40 70 120";
> +
> +static int htu21_read_raw(struct iio_dev *indio_dev,
> +			  struct iio_chan_spec const *channel, int *val,
> +			  int *val2, long mask)
> +{
> +	int ret, temperature;
> +	unsigned int humidity;
> +	struct ms_ht_dev *dev_data = iio_priv(indio_dev);
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_PROCESSED:
> +		switch (channel->type) {
> +		case IIO_TEMP:	/* in milli °C */
> +			ret = ms_sensors_ht_read_temperature(dev_data,
> +							     &temperature);
> +			if (ret)
> +				return ret;
> +			*val = temperature;
> +
> +			return IIO_VAL_INT;
> +		case IIO_HUMIDITYRELATIVE:	/* in milli %RH */
> +			ret = ms_sensors_ht_read_humidity(dev_data,
> +							  &humidity);
> +			if (ret)
> +				return ret;
> +			*val = humidity;
> +
> +			return IIO_VAL_INT;
> +		default:
> +			return -EINVAL;
> +		}
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		*val = htu21_samp_freq[dev_data->res_index];
> +
> +		return IIO_VAL_INT;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static int htu21_write_raw(struct iio_dev *indio_dev,
> +			   struct iio_chan_spec const *chan,
> +			   int val, int val2, long mask)
> +{
> +	struct ms_ht_dev *dev_data = iio_priv(indio_dev);
> +	int i, ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		i = ARRAY_SIZE(htu21_samp_freq);
> +		while (i-- > 0)
> +			if (val == htu21_samp_freq[i])
> +				break;
> +		if (i < 0)
> +			return -EINVAL;
> +		mutex_lock(&dev_data->lock);
> +		dev_data->res_index = i;
> +		ret = ms_sensors_write_resolution(dev_data, i);
> +		mutex_unlock(&dev_data->lock);
> +
> +		return ret;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static const struct iio_chan_spec htu21_channels[] = {
> +	{
> +		.type = IIO_TEMP,
> +		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED),
> +		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
> +	 },
> +	{
> +		.type = IIO_HUMIDITYRELATIVE,
> +		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED),
> +		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
> +	 }
> +};
> +
> +static ssize_t htu21_show_battery_low(struct device *dev,
> +				      struct device_attribute *attr, char *buf)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct ms_ht_dev *dev_data = iio_priv(indio_dev);
> +
> +	return ms_sensors_show_battery_low(dev_data, buf);
> +}
> +
> +static ssize_t htu21_show_heater(struct device *dev,
> +				 struct device_attribute *attr, char *buf)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct ms_ht_dev *dev_data = iio_priv(indio_dev);
> +
> +	return ms_sensors_show_heater(dev_data, buf);
> +}
> +
> +static ssize_t htu21_write_heater(struct device *dev,
> +				  struct device_attribute *attr,
> +				  const char *buf, size_t len)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct ms_ht_dev *dev_data = iio_priv(indio_dev);
> +
> +	return ms_sensors_write_heater(dev_data, buf, len);
> +}
> +
> +static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(htu21_show_samp_freq);
> +static IIO_DEVICE_ATTR(battery_low, S_IRUGO,
> +		       htu21_show_battery_low, NULL, 0);
> +static IIO_DEVICE_ATTR(heater_enable, S_IRUGO | S_IWUSR,
> +		       htu21_show_heater, htu21_write_heater, 0);
> +
> +static struct attribute *htu21_attributes[] = {
> +	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
> +	&iio_dev_attr_battery_low.dev_attr.attr,
> +	&iio_dev_attr_heater_enable.dev_attr.attr,
> +	NULL,
> +};
> +
> +static const struct attribute_group htu21_attribute_group = {
> +	.attrs = htu21_attributes,
> +};
> +
> +static const struct iio_info htu21_info = {
> +	.read_raw = htu21_read_raw,
> +	.write_raw = htu21_write_raw,
> +	.attrs = &htu21_attribute_group,
> +	.driver_module = THIS_MODULE,
> +};
> +
> +int htu21_probe(struct i2c_client *client,
> +		const struct i2c_device_id *id)
> +{
> +	struct ms_ht_dev *dev_data;
> +	struct iio_dev *indio_dev;
> +	int ret;
> +	u64 serial_number;
> +
> +	if (!i2c_check_functionality(client->adapter,
> +				     I2C_FUNC_SMBUS_WRITE_BYTE_DATA |
> +				     I2C_FUNC_SMBUS_WRITE_BYTE |
> +				     I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
> +		dev_err(&client->dev,
> +			"Adapter does not support some i2c transaction\n");
> +		return -ENODEV;
> +	}
> +
> +	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*dev_data));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	dev_data = iio_priv(indio_dev);
> +	dev_data->client = client;
> +	dev_data->res_index = 0;
> +	mutex_init(&dev_data->lock);
> +
> +	indio_dev->info = &htu21_info;
> +	indio_dev->name = id->name;
> +	indio_dev->dev.parent = &client->dev;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->channels = htu21_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(htu21_channels);
> +
> +	i2c_set_clientdata(client, indio_dev);
> +
> +	ret = ms_sensors_reset(client, HTU21_RESET, 15000);
> +	if (ret)
> +		return ret;
> +
> +	ret = ms_sensors_read_serial(client, &serial_number);
> +	if (ret)
> +		return ret;
> +	dev_info(&client->dev, "Serial number : %llx", serial_number);
> +
> +	return devm_iio_device_register(&client->dev, indio_dev);
> +}
> +
> +static const struct i2c_device_id htu21_id[] = {
> +	{"htu21", 0},
> +	{}
> +};
> +
> +static struct i2c_driver htu21_driver = {
> +	.probe = htu21_probe,
> +	.id_table = htu21_id,
> +	.driver = {
> +		   .name = "htu21",
> +		   },
> +};
> +
> +module_i2c_driver(htu21_driver);
> +
> +MODULE_DESCRIPTION("Measurement-Specialties htu21 temperature and humidity driver");
> +MODULE_AUTHOR("William Markezana <william.markezana@meas-spec.com>");
> +MODULE_AUTHOR("Ludovic Tancerel <ludovic.tancerel@maplehightech.com>");
> +MODULE_LICENSE("GPL v2");
>