Re: [PATCH] Add support for ads1110

[Duss Pirmin <pirmin.duss@flytec.ch>]

Hi

On 12/15/2011 05:07 PM, Lars-Peter Clausen wrote:

>> +static struct ads1110_conversion_mode
>> +ads1110_conv_mode_table[ADS1110_MAX_CONV_MODE] = {
>> +  { "continuous-conversion", 0 },
>> +  { "single-conversion", 1 },
>> +};
>
> This should probably not user controllable. You probably want to do a single
> conversion when reading from sysfs and use continuous conversion when using
> a triggered buffer.

As this chip doesn't have an interrupt line all we can do is poll to 
determine if a conversion is completed. my suggestion here is to just 
use continuous conversion and return the last value from the chip. 
Otherwise we would need to poll in the read routine for sysfs. Or is 
there a better way to do it?

>> +static struct attribute *ads1110_attributes[] = {
>> +&iio_dev_attr_available_conversion_modes.dev_attr.attr,
>> +&iio_dev_attr_available_data_rates.dev_attr.attr,
>> +&iio_dev_attr_available_gains.dev_attr.attr,
>> +&iio_dev_attr_value.dev_attr.attr,
>> +&iio_dev_attr_conversion_mode.dev_attr.attr,
>> +&iio_dev_attr_data_rate.dev_attr.attr,
>> +&iio_dev_attr_gain.dev_attr.attr,
>> +&iio_dev_attr_start_conversion.dev_attr.attr,
>> +  NULL,
>> +};
>
> Please use channel_spec. Most of the attributes can probably be expresses
> through it. For those which can not please take a look at
> Documentation/sysfs-bus-iio and see which already existing attribute names
> match your use case. E.g. your "data_rate" should probably be
> "sampling_frequency".
>

Is there an attribute for gain? I'm asking this, because the next chip I 
will write a driver for is the TI ADS1242, which also has a programmable 
gain.

Best regards
Pirmin