Hi, This code will do the rescan of the PCI that we need for the FPGA. However, it currently only supports a single execution after the FPGA gets loaded. Additional calls will continue to add FPGA devices to the PCI device list data structure. I'm going to make some changes to it to handle multiple calls and to support multiple device ids. I'm expecting it to take a day or two, but I'll make an initial cut at it today that will let us load the Spartan FPGA (only once). This driver will be loaded when the kernel boots, so I believe that we'll just need to make a call into it (we won't have to dynamically load it like the phob driver).
Michael, For the FPGA loader, you should load the FPGA, then make a call to pci_rescan_bus0() (I'm renaming check_hw() to pci_rescan_bus0()). Next, you need to do a pci_find_device() to detect the newly loaded FPGA. If the pci_find_device() fails, assume that the FPGA load has not completed, so delay for some time frame (100 ms??), then rescan again. If still not found, rescan up to MAX_PCI_RESCANS (probably set it to 3) times, then return an error that the FPGA load failed. Chris Wyse Member of Technical Staff Embedded Technologies 860-749-1556 office 860-978-0849 cell 413-778-9101 fax http://www.windriver.com -----Original Message----- From: Wyse, Chris Sent: Tuesday, March 07, 2006 8:49 AM To: 'David Hawkins' Cc: 'linuxppc-embedded at ozlabs.org'; Touron, Emmanuel; McComb, Michael Subject: RE: Calling PCI Autoconfig again Hi Dave, Thanks for the input. I was thinking about making the FPGA a hotplug device. I was really hoping that I could just enable CONFIG_HOTPLUG in the kernel build, but after some research, I don't believe that will work. The hotplug approach was more work than I wanted, but after your response, I decided to look into it some more, specifically looking for an FPGA implementation similar to ours. I searched the linux-hotplug-devel list for FPGA, and found this: http://marc.theaimsgroup.com/?l=linux-hotplug-devel&m=101318310111131&w= 2 It implements a rescan of the PCI bus for a newly loaded FPGA device (although despite the group name, it doesn't use HotPlug). I'm going to try to use the code from the above link rather than implement a hotplug driver. Thanks again for the help. Chris Wyse Member of Technical Staff Embedded Technologies 860-749-1556 office 860-978-0849 cell 413-778-9101 fax http://www.windriver.com -----Original Message----- From: David Hawkins [mailto:[EMAIL PROTECTED] Sent: Monday, March 06, 2006 11:33 PM To: Wyse, Chris Cc: linuxppc-embedded at ozlabs.org Subject: Re: Calling PCI Autoconfig again Wyse, Chris wrote: > Hi, > > I'm working on a board (PPC440GX CPU) that has an FPGA on it. The > FPGA software has a PCI interface. If I load the FPGA, then boot the > Linux kernel, the FPGA is recognized as a device on the PCI bus. > However, I'd like to load the FPGA after the kernel has booted, then > run autoconfig again to detect the device. What's the best way to do this? > > Please send responses directly to me (in addition to the list), since > I am not subscribed to the list. Hi Chris, I haven't had to do this, but I've thought about how I might do it. In compact PCI, you can hot-swap a PCI device, and the Linux host is supposed to go and re-enumerate the PCI bus. There is a pci (host-side) hotplug skeleton in the source; linux-2.6/drivers/pci/hotplug/pcihp_skeleton.c I believe you can do the following; - consider the 440GX is a hotplug controller (and write a hotplug driver appropriately) - when Linux loads the FPGA, the FPGA generates a hotplug event, i.e., it just got plugged in (I'm not sure what signal is generated, perhaps a power-management interrupt PME#?) - the 440GX hotplug controller re-enumerates the PCI bus and finds the device I'm sure you can get an idea from the hotplug skeleton what re-enumeration entails. Cheers Dave
