On Fri, Dec 18, 2020 at 10:16:58PM +0100, Alexandre Belloni wrote: > But then again, what about non-enumerable devices on the PCI device? I > feel this would exactly fit MFD. This is a collection of IPs that exist > as standalone but in this case are grouped in a single device. So, if mfd had a mfd_device and a mfd bus_type then drivers would need to have both a mfd_driver and a platform_driver to bind. Look at something like drivers/char/tpm/tpm_tis.c to see how a multi-probe driver is structured See Mark's remarks about the old of_platform_device, to explain why we don't have a 'dt_device' today > Note that I then have another issue because the kernel doesn't support > irq controllers on PCI and this is exactly what my SoC has. But for now, > I can just duplicate the irqchip driver in the MFD driver. I think Thomas fixed that recently on x86 at least.. Having to put dummy irq chip drivers in MFD anything sounds scary :| > Let me point to drivers/net/ethernet/cadence/macb_pci.c which is a > fairly recent example. It does exactly that and I'm not sure you could > do it otherwise while still not having to duplicate most of macb_probe. Creating a platform_device to avoid restructuring the driver's probe and device logic to be generic is a *really* horrible reason to use a platform device. Jason
