On Sat, Dec 5, 2015 at 9:00 AM, Jonathan Cameron <jic23@xxxxxxxxxx> wrote:
> On 01/12/15 03:46, Matt Ranostay wrote:
>> Add support for AMS iAQ-core continuous and pulsed VOC sensors.
>>
>> Signed-off-by: Matt Ranostay <mranostay@xxxxxxxxx>
> The only real question that this raises for me is whether returning the
> last good value is a good idea if the sensor isn't ready to take a new
> one yet...
>
> Otherwise a few bits and bobs inline.
>> ---
>> .../devicetree/bindings/i2c/trivial-devices.txt | 1 +
>> drivers/iio/chemical/Kconfig | 8 +
>> drivers/iio/chemical/Makefile | 1 +
>> drivers/iio/chemical/ams-iaq-core.c | 190 +++++++++++++++++++++
>> 4 files changed, 200 insertions(+)
>> create mode 100644 drivers/iio/chemical/ams-iaq-core.c
>>
>> diff --git a/Documentation/devicetree/bindings/i2c/trivial-devices.txt b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>> index c50cf13..f6fec95 100644
>> --- a/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>> +++ b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>> @@ -20,6 +20,7 @@ adi,adt7476 +/-1C TDM Extended Temp Range I.C
>> adi,adt7490 +/-1C TDM Extended Temp Range I.C
>> adi,adxl345 Three-Axis Digital Accelerometer
>> adi,adxl346 Three-Axis Digital Accelerometer (backward-compatibility value "adi,adxl345" must be listed too)
>> +ams,iaq-core AMS iAQ-Core VOC Sensor
>> at,24c08 i2c serial eeprom (24cxx)
>> atmel,24c00 i2c serial eeprom (24cxx)
>> atmel,24c01 i2c serial eeprom (24cxx)
>> diff --git a/drivers/iio/chemical/Kconfig b/drivers/iio/chemical/Kconfig
>> index 3061b72..f16de61 100644
>> --- a/drivers/iio/chemical/Kconfig
>> +++ b/drivers/iio/chemical/Kconfig
>> @@ -4,6 +4,14 @@
>>
>> menu "Chemical Sensors"
>>
>> +config IAQCORE
>> + tristate "AMS iAQ-Core VOC sensors"
>> + depends on I2C
>> + help
>> + Say Y here to build I2C interface support for the AMS
>> + iAQ-Core Continuous/Pulsed VOC (Volatile Organic Compounds)
>> + sensors
>> +
>> config VZ89X
>> tristate "SGX Sensortech MiCS VZ89X VOC sensor"
>> depends on I2C
>> diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile
>> index 7292f2d..167861f 100644
>> --- a/drivers/iio/chemical/Makefile
>> +++ b/drivers/iio/chemical/Makefile
>> @@ -3,4 +3,5 @@
>> #
>>
>> # When adding new entries keep the list in alphabetical order
>> +obj-$(CONFIG_IAQCORE) += ams-iaq-core.o
>> obj-$(CONFIG_VZ89X) += vz89x.o
>> diff --git a/drivers/iio/chemical/ams-iaq-core.c b/drivers/iio/chemical/ams-iaq-core.c
>> new file mode 100644
>> index 0000000..db9aa39
>> --- /dev/null
>> +++ b/drivers/iio/chemical/ams-iaq-core.c
>> @@ -0,0 +1,190 @@
>> +/*
>> + * ams-iaq-core.c - Support for AMS iAQ-Core VOC sensors
>> + *
>> + * Copyright (C) 2015 Matt Ranostay <mranostay@xxxxxxxxx>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License as published by
>> + * the Free Software Foundation; either version 2 of the License, or
>> + * (at your option) any later version.
>> + *
>> + * 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.
>> + *
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/mutex.h>
>> +#include <linux/init.h>
>> +#include <linux/i2c.h>
>> +#include <linux/iio/iio.h>
>> +
>> +#define AMS_IAQCORE_DATA_SIZE 9
>> +
>> +#define AMS_IAQCORE_VOC_CO2_IDX 0
>> +#define AMS_IAQCORE_VOC_RESISTANCE_IDX 1
>> +#define AMS_IAQCORE_VOC_TVOC_IDX 2
>> +
>> +struct ams_iaqcore_reading {
>> + __be16 co2_ppm;
>> + u8 status;
>> + __be32 resistance;
>> + __be16 voc_ppb;
>> +} __attribute__((__packed__));
>> +
>> +struct ams_iaqcore_data {
>> + struct i2c_client *client;
>> + struct mutex lock;
>> + unsigned long last_update;
>> +
>> + struct ams_iaqcore_reading buffer;
>> +};
>> +
>> +static const struct iio_chan_spec ams_iaqcore_channels[] = {
>> + {
>> + .type = IIO_CONCENTRATION,
>> + .channel2 = IIO_MOD_CO2,
>> + .modified = 1,
>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> No info at all on scaling etc? ppm is mentioned on the
> data sheet.
D'oh forgot the scaling to convert it to the processed
IIO_CONCENTRATION value. Will fix in v2
>> + .address = AMS_IAQCORE_VOC_CO2_IDX,
>> + },
>> + {
>> + .type = IIO_RESISTANCE,
>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> As I read the datahsheet this is in ohms anyway so
> IIO_CHAN_INFO_PROCESSED is more appropriate.
>> + .address = AMS_IAQCORE_VOC_RESISTANCE_IDX,
>> + },
>> + {
>> + .type = IIO_CONCENTRATION,
>> + .channel2 = IIO_MOD_VOC,
>> + .modified = 1,
> Again datasheet implies you can give this a scaling...
>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
>> + .address = AMS_IAQCORE_VOC_TVOC_IDX,
>> + },
>> +};
>> +
>> +static int ams_iaqcore_read_measurement(struct ams_iaqcore_data *data)
>> +{
>> + struct i2c_client *client = data->client;
>> + int ret;
>> +
>> + struct i2c_msg msg[] = {
>> + {
>> + .addr = client->addr,
>> + .flags = client->flags | I2C_M_RD,
>> + .len = AMS_IAQCORE_DATA_SIZE,
>> + .buf = (char *) &data->buffer,
>> + },
> Why have an array? Just drop that and pass &msg into the i2c
> transfer call.
Noted.
>> + };
>> +
>> + ret = i2c_transfer(client->adapter, msg, 1);
>> +
>> + return (ret == AMS_IAQCORE_DATA_SIZE) ? 0 : ret;
>> +}
>> +
>> +static int ams_iaqcore_get_measurement(struct ams_iaqcore_data *data)
>> +{
>> + int ret;
>> +
>> + /* sensor can only be polled once a second max per datasheet */
>> + if (!time_after(jiffies, data->last_update + HZ))
>> + return 0;
>> +
>> + ret = ams_iaqcore_read_measurement(data);
>> + if (ret < 0)
>> + return ret;
>> +
>> + data->last_update = jiffies;
>> +
>> + return 0;
>> +}
>> +
>> +static int ams_iaqcore_read_raw(struct iio_dev *indio_dev,
>> + struct iio_chan_spec const *chan, int *val,
>> + int *val2, long mask)
>> +{
>> + struct ams_iaqcore_data *data = iio_priv(indio_dev);
>> + int ret = -EINVAL;
>> +
>> + if (mask != IIO_CHAN_INFO_RAW)
>> + return -EINVAL;
>> +
>> + mutex_lock(&data->lock);
>> + ret = ams_iaqcore_get_measurement(data);
>> + mutex_unlock(&data->lock);
>> +
>> + if (ret)
>> + return ret;
>> +
>> + switch (chan->address) {
>> + case AMS_IAQCORE_VOC_CO2_IDX:
>> + *val = be16_to_cpu(data->buffer.co2_ppm);
>> + return IIO_VAL_INT;
>> + case AMS_IAQCORE_VOC_RESISTANCE_IDX:
>> + *val = be32_to_cpu(data->buffer.resistance);
>> + return IIO_VAL_INT;
>> + case AMS_IAQCORE_VOC_TVOC_IDX:
>> + *val = be16_to_cpu(data->buffer.voc_ppb);
>> + return IIO_VAL_INT;
>> + }
> nitpick of the day - blank line here please :)
>> + return ret;
>> +}
>> +
>> +static const struct iio_info ams_iaqcore_info = {
>> + .read_raw = ams_iaqcore_read_raw,
>> + .driver_module = THIS_MODULE,
>> +};
>> +
>> +static int ams_iaqcore_probe(struct i2c_client *client,
>> + const struct i2c_device_id *id)
>> +{
>> + struct iio_dev *indio_dev;
>> + struct ams_iaqcore_data *data;
>> +
>> + 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;
> Would have liked a comment here on why the take one second off...
> Fairly obvious though so not that important.
Ah okay will add comment for this.
>
>> + data->last_update = jiffies - HZ;
>> + mutex_init(&data->lock);
>> +
>> + indio_dev->dev.parent = &client->dev;
>> + indio_dev->info = &ams_iaqcore_info,
>> + indio_dev->name = dev_name(&client->dev);
>> + indio_dev->modes = INDIO_DIRECT_MODE;
>> +
>> + indio_dev->channels = ams_iaqcore_channels;
>> + indio_dev->num_channels = ARRAY_SIZE(ams_iaqcore_channels);
>> +
>> + return devm_iio_device_register(&client->dev, indio_dev);
>> +}
>> +
>> +static const struct i2c_device_id ams_iaqcore_id[] = {
>> + { "ams-iaq-core", 0 },
>> + { }
>> +};
>> +MODULE_DEVICE_TABLE(i2c, ams_iaqcore_id);
>> +
>> +static const struct of_device_id ams_iaqcore_dt_ids[] = {
>> + { .compatible = "ams,iaq-core" },
>> + { }
>> +};
>> +MODULE_DEVICE_TABLE(of, ams_iaqcore_dt_ids);
>> +
>> +static struct i2c_driver ams_iaqcore_driver = {
>> + .driver = {
>> + .name = "ams-iaq-core",
>> + .of_match_table = of_match_ptr(ams_iaqcore_dt_ids),
>> + },
>> + .probe = ams_iaqcore_probe,
>> + .id_table = ams_iaqcore_id,
>> +};
>> +module_i2c_driver(ams_iaqcore_driver);
>> +
>> +MODULE_AUTHOR("Matt Ranostay <mranostay@xxxxxxxxx>");
>> +MODULE_DESCRIPTION("AMS iAQ-Core VOC sensors");
>> +MODULE_LICENSE("GPL v2");
>>
>
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