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

[Alexandre Belloni <alexandre.belloni@free-electrons.com>]

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.



-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com