Re: [PATCH v3 4/5] iio: mxs-lradc: add scale_available file to channels

[Jonathan Cameron <jic23@kernel.org>]

Alexandre Belloni <alexandre.belloni@free-electrons.com> wrote:
>On 23/07/2013 15:25, Hector Palacios wrote:
>> Dear Lars,
>>
>> On 07/23/2013 10:46 AM, Lars-Peter Clausen wrote:
>>> On 07/22/2013 04:04 PM, Hector Palacios wrote:
>>> [...]
>>>>
>>>> +static ssize_t mxs_lradc_show_scale_available_ch(struct device
>*dev,
>>>> +        struct device_attribute *attr,
>>>> +        char *buf,
>>>> +        int ch)
>>>> +{
>>>> +    struct iio_dev *iio = dev_to_iio_dev(dev);
>>>> +    struct mxs_lradc *lradc = iio_priv(iio);
>>>> +    int i, len = 0;
>>>> +
>>>> +    for (i = 0; i < ARRAY_SIZE(lradc->scale_avail[ch]); i++)
>>>> +        len += sprintf(buf + len, "%d.%09u ",
>>>> +                   lradc->scale_avail[ch][i].integer,
>>>> +                   lradc->scale_avail[ch][i].nano);
>>>> +
>>>> +    len += sprintf(buf + len, "\n");
>>>> +
>>>> +    return len;
>>>> +}
>>>> +
>>>> +static ssize_t mxs_lradc_show_scale_available(struct device *dev,
>>>> +        struct device_attribute *attr,
>>>> +        char *buf)
>>>> +{
>>>> +    struct iio_dev_attr *iio_attr = to_iio_dev_attr(attr);
>>>> +
>>>> +    return mxs_lradc_show_scale_available_ch(dev, attr, buf,
>>>> +                         iio_attr->address);
>>>> +}
>>>> +
>>>> +#define SHOW_SCALE_AVAILABLE_ATTR(ch)                    \
>>>> +static IIO_DEVICE_ATTR(in_voltage##ch##_scale_available, S_IRUGO, 
>  \
>>>> +               mxs_lradc_show_scale_available, NULL, ch)
>>>> +
>>>> +SHOW_SCALE_AVAILABLE_ATTR(0);
>>>> +SHOW_SCALE_AVAILABLE_ATTR(1);
>>>> +SHOW_SCALE_AVAILABLE_ATTR(2);
>>>> +SHOW_SCALE_AVAILABLE_ATTR(3);
>>>> +SHOW_SCALE_AVAILABLE_ATTR(4);
>>>> +SHOW_SCALE_AVAILABLE_ATTR(5);
>>>> +SHOW_SCALE_AVAILABLE_ATTR(6);
>>>> +SHOW_SCALE_AVAILABLE_ATTR(7);
>>>> +SHOW_SCALE_AVAILABLE_ATTR(8);
>>>> +SHOW_SCALE_AVAILABLE_ATTR(9);
>>>> +SHOW_SCALE_AVAILABLE_ATTR(10);
>>>> +SHOW_SCALE_AVAILABLE_ATTR(11);
>>>> +SHOW_SCALE_AVAILABLE_ATTR(12);
>>>> +SHOW_SCALE_AVAILABLE_ATTR(13);
>>>> +SHOW_SCALE_AVAILABLE_ATTR(14);
>>>> +SHOW_SCALE_AVAILABLE_ATTR(15);
>>>> +
>>>> +static struct attribute *mxs_lradc_attributes[] = {
>>>> +    &iio_dev_attr_in_voltage0_scale_available.dev_attr.attr,
>>>> +    &iio_dev_attr_in_voltage1_scale_available.dev_attr.attr,
>>>> +    &iio_dev_attr_in_voltage2_scale_available.dev_attr.attr,
>>>> +    &iio_dev_attr_in_voltage3_scale_available.dev_attr.attr,
>>>> +    &iio_dev_attr_in_voltage4_scale_available.dev_attr.attr,
>>>> +    &iio_dev_attr_in_voltage5_scale_available.dev_attr.attr,
>>>> +    &iio_dev_attr_in_voltage6_scale_available.dev_attr.attr,
>>>> +    &iio_dev_attr_in_voltage7_scale_available.dev_attr.attr,
>>>> +    &iio_dev_attr_in_voltage8_scale_available.dev_attr.attr,
>>>> +    &iio_dev_attr_in_voltage9_scale_available.dev_attr.attr,
>>>> +    &iio_dev_attr_in_voltage10_scale_available.dev_attr.attr,
>>>> +    &iio_dev_attr_in_voltage11_scale_available.dev_attr.attr,
>>>> +    &iio_dev_attr_in_voltage12_scale_available.dev_attr.attr,
>>>> +    &iio_dev_attr_in_voltage13_scale_available.dev_attr.attr,
>>>> +    &iio_dev_attr_in_voltage14_scale_available.dev_attr.attr,
>>>> +    &iio_dev_attr_in_voltage15_scale_available.dev_attr.attr,
>>>> +    NULL
>>>> +};
>>>
>>> This should really be using the iio_chan_spec_ext_info
>>> infrastructure. Bonus
>>> points for factoring out the common code used to calculate and
>>> display the
>>> scales.
>>
>> I perfectly understand. Sadly, I don't currently have the time and
>> expertise to try to work this out the proper way. It already took
>much
>> longer than expected to have this driver toggle a divider flag.
>>
>> I'd appreciate if anyone wishes to complete this job.
>> @Alexander, please feel free to submit your other temp patch without
>> waiting for this one.
>>
>
>Maybe, we can get the patch set as is and do further clean up later.
>Anyway, that driver is still in staging, right ?
>
>As said, I'm willing to propose something for the scale calculation.

My thoughts exactly. Long term plans include generic handling of available attributes for the whole of IIO.

It will take me a little while to catch up my backlog though!

Jonathan



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