[PATCH 2/3] ARM: AT91: IIO: Add AT91 ADC driver.

Maxime Ripard
2011-11-14T14:23:09Z

Hi

On 14/11/2011 12:37, Marek Vasut wrote:
>> + idev->num_channels = bitmap_weight(&(pdata->channels_used),
>
> Do you need the parenthesis here ?

No. I just find it clearer this way, but it's all about cosmetic.

>> + pdata->num_channels);
>> + chan_array = kcalloc(idev->num_channels, sizeof(struct iio_chan_spec),
>> + GFP_KERNEL);
>> +
>> + if (chan_array == NULL)
>> + return -ENOMEM;
>> +
>> + for_each_set_bit(bit, &(pdata->channels_used), pdata->num_channels) {
>> + struct iio_chan_spec *chan = chan_array + idx;
>> + chan->type = IIO_VOLTAGE;
>> + chan->indexed = 1;
>> + chan->channel = bit;
>> + chan->scan_type.sign = 'u';
>> + chan->scan_type.realbits = 10;
>> + chan->info_mask = IIO_CHAN_INFO_SCALE_SHARED_BIT;
>> + ++idx;
>
> idx++ ... why the preincrement?
>
> Besides, can't you use "bit" as the index instead?

Nope. bit is the index in the pdata->channel_used array, while idx is
the index in the chan_array array. And since these two don't have the
same length, I need these two variables.

--
Maxime Ripard, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.