<snip> >> + converters (DACs), that functionality is also supported. > > > I wouldn't necessarily treat DACs and ADCs differently here. Maybe something > like: > > The main purpose of the Industrial I/O subsystem (IIO) is to provide > support for devices that in some sense perform either analog-to-digital > conversion (ADC) or digital-to-analog conversion (DAC) or both. Ok. Fixed. >> + <para> In order to be useful, a buffer needs to have an associated >> + trigger. Future chapters will add details about triggers and how >> + drivers use triggers to start data capture, moving samples from >> device >> + registers to buffer storage and then upward to user space >> applications. > > > Buffers don't have to have a trigger, only triggered buffers need them. > Although admittedly most buffers will be triggered buffers. I think it's > better to talk about buffers in general first and then discuss the different > types of buffers and when to use them. In this context it should be > mentioned that a triggered buffer needs a trigger to function. I removed this paragraph for the moment, will try to add more info about buffer here with a follow up patch. <snip> >> + </itemizedlist> > > > The scan type gained a repeat field a while ago. Nice catch. Fixed. Also will send a patch to fix the ABI entry description. <snip> >> + Here <emphasis> scan_index </emphasis> is used for ordering data >> samples >> + (scans) when read from buffer. > > > A bit more: > > scan_index defines the relative order in which the enabled channels > are placed inside the buffer, a channel with a lower scan_index will be > placed before a channel with a higher index. Each channels needs to have > a unique scan_index. > > It is important to realize that the scan_index does not define the > absolution position in the buffer. E.g. a channel with the scan_index = 3 > will not be at offset 3 bytes or 3 words, but rather will be placed in > the buffer after any channel with a scan_index lower than 3 and before > any channel with a scan_index larger than 3. > > Furthermore the scan indices do not have to be consecutive. E.g. A > channel spec array that defines 3 channels with the indices 1, 2 and 3 is > just as valid as a channel spec that uses the indices 100, 200, 300. The > relative order of the channels will be the same. > > Setting scan_index to -1 can be used to indicate that the specific > channel does not support buffered capture. In this case no entries will > be created for the channel in the scan_elements directory. Nice. I've included this in the documentation. Thanks a lot Lars for your review. Daniel. -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
