On Sat, Mar 13, 2021 at 10:45:57AM +0100, Henning Schild wrote: > Am Mon, 8 Mar 2021 14:20:16 +0200 > schrieb Andy Shevchenko <andriy.shevche...@linux.intel.com>:
... > > + * pci_p2sb_bar - Get Primary to Sideband bridge (P2SB) device BAR > > + * @pdev: PCI device to get a PCI bus to communicate with > > + * @devfn: PCI slot and function to communicate with > > + * @mem: memory resource to be filled in > > Do we really need that many arguments to it? > > Before i had, in a platform driver that never had its own pci_dev or bus > > res->start = simatic_ipc_get_membase0(PCI_DEVFN(13, 0)); > if (res-start == 0) > return -ENODEV; > > So helper only asked for the devfn, returned base and no dedicated > error code. > > With this i need > > struct pci_bus *bus = pci_find_bus(0, 0); > struct pci_dev *pci_dev = bus->self; > unsigned int magic_i_do_not_want = PCI_DEVFN(13, 0); What confuses me is the use for SPI NOR controller on Broxton. And I think we actually can indeed hide all this under the hood by exposing P2SB to the OS. Mika, what do you think? > I guess that second devfn is for devices behind that bridge. So > unhiding it might reveal several devices? Good question. I need a device where actually this happens (hidden P2SB stuff with let's say SPI NOR there) to see how it looks like in such case. I only understood the GPIO part. But I'm not so sure anymore. > But when caring about that > p2sb do i really need to know its devfn. If so i would like to get -- With Best Regards, Andy Shevchenko
