Hi Pavel, I’m fairly new to IIO, but I am working on a somewhat similar project. One important question is how you are intending to transport your data from the FPGA to your CPU? Do you have a DMA engine of some kind, with a linux driver? Or perhaps a wire protocol, such as SPI or I2C? What’s your realtime requirements? That is, if your data rate is 12.5k/sec, so how much buffer space do you have on the hardware? Typically you would aim to drain the hardware when it is 50% full, so that would give you an idea of how frequently you’d need to service your hardware buffer. Stock Linux isn’t going to be your friend if your realtime requirements are tight. Don’t rely on interrupt latencies less than 10s of milliseconds, or even more on busy systems. Jonah > On Apr 7, 2017, at 5:48 PM, Pavel Roskin <plroskin@xxxxxxxxx> wrote: > > Hello, > > I'm writing a driver for an FPGA device that collects information from > several sensors. The data is collected every 20 milliseconds (i.e. 50 > times a second). The data is a 256 byte block that is put to a ring > buffer in the hardware. The software should read the data quickly to > avoid it being overwritten in the ring buffer. It is very important > not to lose any data; previous values are just as important as the > current ones. No parsing needs to be done in the kernel; the userspace > will take care of it. > > Is IIO a good choice for such device? I see that the existing IIO > drivers are careful to describe all data they collect. I'm not going > to do that in the kernel (OK, maybe later to allow other utilities to > get the parsed data, but it can be done in userspace too). > > I would really appreciate is somebody could point me to a driver that > implements similar functionality. > > -- > Regards, > Pavel Roskin > -- > 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 -- 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
