Hi, > > Atari SCC variants have their own quirks, so something more configurable > > will be needed. > > We probably should have an SCC/ESCC core driver the way we have for > a lot of the other common chips like 8390 ethernet or ESP SCSI. I > know there's lots of systems with these chips that each have drivers. Didn't seem too many of those in drivers/serial ... > > What are the quirks the m68k mac SCC driver woukd add? From memory, I have this > > Most of the m68k mac serial quirks are the same as the ones in the > pmac serial driver. There is only one interrupt for both ports, but According to my 2.2.25 source, SCC A is at interrupt number 33, SCC B is at 34. Did that change with tha A/UX interrupt style? What seems to be true is all interrupt types for a given channel go to the same handler... The platform device would need to have one interrupt number each for TX, RX, status and special condition for each channel, plus data/control ports forr each, plus flags. The Mac platform device would have only one interrupt per channel (and perhaps a flag indicating that). > the drivers do funny things to make it look mostly like each port > has its own interrupt. There are some odd things about how Apple > hooked up the hardware flow control. I suspect that any models with Right you are ... > built-in modems need enable/disable code for that on m68k macs Are there any Macs with builtin modems in the standard configuration? > There isn't much m68k mac specific, and I don't think the issues > you mention for Atari are issues on macs. The AV systems have > DMA but don't have a tx-dma channel for the second port. The one > interrupt is hooked up to IRQ 4, which means it doesn't go through This is on AV Macs only (because the PSC interrupts are at 32-35 there)? > > Can the platform bus device code define architecture specific init callbacks > > to hide this? > > We could probably do something along those lines, but I can't see > tying it directly to the platform bus. I think it would be better > to make a zilog SCC/ESCC core driver and write a driver for each > bus interface type the way the ESP driver now works. It just seems > simpler from a code maintenance perspective. I don't think using callbacks would be a clean way of handling this, so your idea may be better. VME and Atari used to use the same driver in 2.2 so that should still be possible now. Michael -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
