> On Mar 25, 2018, at 9:54 AM, Jonathan Cameron <jic23@xxxxxxxxxx> wrote: > > On Sun, 25 Mar 2018 01:29:41 -0700 > John Syne <john3909@xxxxxxxxx> wrote: > >> Hi Jonathan, > Hi John, > > Please wrap your normal emails (excepting tables) to 80 chars. Yeah, I’m trying to do that, but I use a Mac and Apple Mail doesn’t have a feature to wrap at 80 automatically so I have to do this manually. > >> >> I was speaking with Rodrigo and here is what I think must be done to move >> ADE7878 out of staging >> >> Here are the steps as I see them: >> >> 1) Define the IIO Attributes so they are consistent with the IIO ABI. This >> should be pretty simple given agreement on the naming convention. > Please don't go just changing attribute names - the driver needs to > use the standard approach of iio_chan_spec and create the vast > majority of attributes automatically via that. There 'may' be > a few corner cases wee don't want to make generic and they 'might' > be exposed as attributes. > > I suspect this change is the 'big' job. The core support necessary > for RMS and MAV (computedtype or whatever we call it) will need adding > as well. That is a separate patch set with support for some examples > in the dummy driver. Great that you mentioned this, because I though we only needed to modify the IIO_ATTR naming. I’ll take a look at iio_chan_spec and the examples in the dummy driver. > >> 2) Map the ADE7854 interrupt status to IIO events. This requires an >> interrupt processing section. >> 3) Add DeviceTree support. >> 4) Create DeviceTree overlay for the ADE7854. > More a case of bindings for now. If those are used via an overlay > fine but given we don't have any boards with one one in mainline, > this is an implementation detail for the user rather than part > of moving this driver out of staging. I was thinking more along the lines of documentation to show a developer what was needed to get the driver working. > >> 5) Update ADE7854 probe to read in the DeviceTree register settings. >> 6) Add support for power modes (PM1, PM2). > This isn't necessary for a move out of staging (nice to have though). > >> 7) Not sure if we will support measurement streaming on the ADE7854. >> The problem is ADE7854 is designed as an SPI master, which means >> it controls the SPI clock, so the driver must support SPI slave >> mode. However, the Linux Kernel does not currently support SPI >> slave mode. We have three choices to make this work and they >> are all a lot of work: 1) Add support for SPI Slave mode to the >> kernel, 2) Use hardware to convert SPI signals to I2S signals >> and with the use of a custom codec, use the ALSA framework to >> stream the samples (this is an approach I used, but I don’t like >> it), 3) Move the I2S driver out of the sound subsystem and use it >> together with DMA to stream samples directly into the ADE7854 driver >> (my preferred solutions). Perhaps Mark Brown has some ideas on how >> to make this work. > I'll be honest, this is an end of line part and frankly more than > a little crazy. I would go with simply not supporting the measurement > streaming at all for this part. If you really need it we can then > move onto the how part, but from what you have said I'm guessing you > don't care except in an abstract 'it would be nice' sort of a way? Yeah, I’m moving to the ADE9000 so I’ll drop this. > >> >> The ADE9000 will be much easier because it uses an SPI Slave interface. >> >> I hope I have captured everything, but let me know if I have missed anything. >> > > That will do for now ;) I'm sure there will be details that need > tidying up once we have the above done, but that's true for any new > driver (and this will be nearly a new driver before things are done). Thank you again for all the detailed feedback. > > Jonathan -- 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
