Re: [Patch v6 3/6] IIO: core: Modify scan element type

[Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>]

On 04/25/2014 11:02 AM, Jonathan Cameron wrote:
> On 15/04/14 19:21, Srinivas Pandruvada wrote:
>> The current scan element type uses the following format:
>>    [be|le]:[s|u]bits/storagebits[>>shift].
>> To specify multiple elements in this type, added a repeat value.
>> So new format is:
>>    [be|le]:[s|u]bits/storagebits{X[repeat]}[>>shift].
>> Here X is specifying how may times, real/storage bits are repeating.
>>
>> When X is value is 0 or 1, then repeat value is not used in the format,
>> and it will be same as existing format.
>>
>> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
> Hi Srinivas,
>
> I'm afraid I've been rather useless in my reviewing of earlier 
> versions of this.
> What I originally meant to suggest was that we'd have descriptions 
> along the lines
> of
> u12/16{X4}>>2 (or u12/16X4>>2 without the brackets) rather than 
> u12/16{4repeat}>>2
I don't mind using u12/16X4>>2, will submit series again.

Thanks,
Srinivas
>
> Now obviously you've gone a long way with this approach so I guess 
> perhaps people
> actually like the word repeat in there?
>
> Sorry again that I didn't pick up on this in any of the last 4 
> versions you have posted.
> Sometimes the eye sees what it expects to rather than what is there!
>
> I don't particularly mind the version using the word 'repeat' if 
> others like, it simply
> isn't what I thought we had here!
>
> (the rest of this series are fine now btw)
>
> J
>> ---
>>   drivers/iio/industrialio-buffer.c | 41 
>> +++++++++++++++++++++++++++++++++------
>>   include/linux/iio/iio.h           |  7 +++++++
>>   2 files changed, 42 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/iio/industrialio-buffer.c 
>> b/drivers/iio/industrialio-buffer.c
>> index e108f2a..aa90c68 100644
>> --- a/drivers/iio/industrialio-buffer.c
>> +++ b/drivers/iio/industrialio-buffer.c
>> @@ -150,7 +150,16 @@ static ssize_t iio_show_fixed_type(struct device 
>> *dev,
>>           type = IIO_BE;
>>   #endif
>>       }
>> -    return sprintf(buf, "%s:%c%d/%d>>%u\n",
>> +    if (this_attr->c->scan_type.repeat > 1)
>> +        return sprintf(buf, "%s:%c%d/%d{%d[repeat]}>>%u\n",
>> +               iio_endian_prefix[type],
>> +               this_attr->c->scan_type.sign,
>> +               this_attr->c->scan_type.realbits,
>> +               this_attr->c->scan_type.storagebits,
>> +               this_attr->c->scan_type.repeat,
>> +               this_attr->c->scan_type.shift);
>> +        else
>> +            return sprintf(buf, "%s:%c%d/%d>>%u\n",
>>                  iio_endian_prefix[type],
>>                  this_attr->c->scan_type.sign,
>>                  this_attr->c->scan_type.realbits,
>> @@ -474,14 +483,22 @@ static int iio_compute_scan_bytes(struct 
>> iio_dev *indio_dev,
>>       for_each_set_bit(i, mask,
>>                indio_dev->masklength) {
>>           ch = iio_find_channel_from_si(indio_dev, i);
>> -        length = ch->scan_type.storagebits / 8;
>> +        if (ch->scan_type.repeat > 1)
>> +            length = ch->scan_type.storagebits / 8 *
>> +                ch->scan_type.repeat;
>> +        else
>> +            length = ch->scan_type.storagebits / 8;
>>           bytes = ALIGN(bytes, length);
>>           bytes += length;
>>       }
>>       if (timestamp) {
>>           ch = iio_find_channel_from_si(indio_dev,
>>                             indio_dev->scan_index_timestamp);
>> -        length = ch->scan_type.storagebits / 8;
>> +        if (ch->scan_type.repeat > 1)
>> +            length = ch->scan_type.storagebits / 8 *
>> +                ch->scan_type.repeat;
>> +        else
>> +            length = ch->scan_type.storagebits / 8;
>>           bytes = ALIGN(bytes, length);
>>           bytes += length;
>>       }
>> @@ -957,7 +974,11 @@ static int iio_buffer_update_demux(struct 
>> iio_dev *indio_dev,
>>                              indio_dev->masklength,
>>                              in_ind + 1);
>>               ch = iio_find_channel_from_si(indio_dev, in_ind);
>> -            length = ch->scan_type.storagebits/8;
>> +            if (ch->scan_type.repeat > 1)
>> +                length = ch->scan_type.storagebits / 8 *
>> +                    ch->scan_type.repeat;
>> +            else
>> +                length = ch->scan_type.storagebits / 8;
>>               /* Make sure we are aligned */
>>               in_loc += length;
>>               if (in_loc % length)
>> @@ -969,7 +990,11 @@ static int iio_buffer_update_demux(struct 
>> iio_dev *indio_dev,
>>               goto error_clear_mux_table;
>>           }
>>           ch = iio_find_channel_from_si(indio_dev, in_ind);
>> -        length = ch->scan_type.storagebits/8;
>> +        if (ch->scan_type.repeat > 1)
>> +            length = ch->scan_type.storagebits / 8 *
>> +                ch->scan_type.repeat;
>> +        else
>> +            length = ch->scan_type.storagebits / 8;
>>           if (out_loc % length)
>>               out_loc += length - out_loc % length;
>>           if (in_loc % length)
>> @@ -990,7 +1015,11 @@ static int iio_buffer_update_demux(struct 
>> iio_dev *indio_dev,
>>           }
>>           ch = iio_find_channel_from_si(indio_dev,
>>               indio_dev->scan_index_timestamp);
>> -        length = ch->scan_type.storagebits/8;
>> +        if (ch->scan_type.repeat > 1)
>> +            length = ch->scan_type.storagebits / 8 *
>> +                ch->scan_type.repeat;
>> +        else
>> +            length = ch->scan_type.storagebits / 8;
>>           if (out_loc % length)
>>               out_loc += length - out_loc % length;
>>           if (in_loc % length)
>> diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
>> index 5629c92..ccde917 100644
>> --- a/include/linux/iio/iio.h
>> +++ b/include/linux/iio/iio.h
>> @@ -177,6 +177,12 @@ struct iio_event_spec {
>>    *            shift:        Shift right by this before masking out
>>    *                    realbits.
>>    *            endianness:    little or big endian
>> + *            repeat:        Number of times real/storage bits
>> + *                    repeats. When the repeat element is
>> + *                    more than 1, then the type element in
>> + *                    sysfs will show a repeat value.
>> + *                    Otherwise, the number of repetitions is
>> + *                    omitted.
>>    * @info_mask_separate: What information is to be exported that is 
>> specific to
>>    *            this channel.
>>    * @info_mask_shared_by_type: What information is to be exported 
>> that is shared
>> @@ -219,6 +225,7 @@ struct iio_chan_spec {
>>           u8    realbits;
>>           u8    storagebits;
>>           u8    shift;
>> +        u8    repeat;
>>           enum iio_endian endianness;
>>       } scan_type;
>>       long            info_mask_separate;
>>
>
>