[U-Boot] Device tree & PCI/ECAM questions

[Jagan Teki]

On Tue, Nov 1, 2016 at 6:49 AM, Aaron Williams
<Aaron.Williams at caviumnetworks.com> wrote:
> Hi all,
>
> I am working on several drivers for our Octeon-TX/Thunder chips which talk
> to devices connected to the ECAM bus through another sub-bus and am having
> issues regarding the device tree.
>
> We have a "PCI" driver to handle the ECAM and I created a simple-bus stub
> for our MRML bus which connects low-speed devices to the ECAM bus and all of
> the devices show up in the device tree.
>
> My problem is that the devices also enumerated via PCI.
>
> I have something like the following:
>
> static int cavium_pci_mmc_probe(struct udevice *dev)
> {
>     debug("%s: Entry\n", __func__);
>     pci_dev_t bdf = dm_pci_get_bdf(dev);
>     struct cavium_mmc_host *host = dev_get_priv(dev);
>     size_t size;
>     uint64_t base_addr = dm_pci_map_bar(dev, 0, &size, PCI_REGION_MEM);
>     int rc = 0;
>
>     host->base_addr = base_addr;
>     dev->req_seq = PCI_FUNC(bdf);
>
>     debug("%s(%s): ", __func__, dev->name);
>     debug("  platdata:        %p\n"
>           "  parent platdata: %p\n"
>           "  uclass platdata: %p\n"
>           "  base address:    %lx\n"
>           "  of_offset:       %d\n"
>           "  parent:          %p\n"
>           "  priv:            %p\n"
>           "  uclass:          %p\n"
>           "  req_seq:         %d\n"
>           "  seq:             %d\n",
>           dev->platdata, dev->parent_platdata,
>           dev->uclass_platdata, base_addr,
>           dev->of_offset, dev->parent, dev->priv,
>           dev->uclass, dev->req_seq, dev->seq);
>
>     if (dev->of_offset >= 0)
>         rc = process_node(dev, gd->fdt_blob, dev->of_offset);
>
>     return rc;
> }
>
> static const struct udevice_id cavium_mmc_ids[] = {
>     { .compatible = "cavium,thunder-8890-mmc" },
>     { .compatible = "cavium,mmc" },
>     { },
> };
>
> static const struct udevice_id cavium_mmc_slot_ids[] = {
>     { .compatible = "cavium,thunder-8890-mmc-slot" },
>     { },
> };
>
> U_BOOT_DRIVER(cavium_pci_mmc) = {
>     .name    = "mmc_cavium",
>     .id    = UCLASS_MMC,
>     .of_match = of_match_ptr(cavium_mmc_ids),
>     .ofdata_to_platdata = cavium_mmc_ofdata_to_platdata,
>     .probe    = cavium_pci_mmc_probe,
>     .priv_auto_alloc_size = sizeof(struct cavium_mmc_host),
>     .ops = NULL,
> };
>
> static struct pci_device_id cavium_pci_mmc_supported[] = {
>     { PCI_VDEVICE(CAVIUM, PCI_DEVICE_ID_THUNDER_MMC) },
>     {},
> };
>
> U_BOOT_PCI_DEVICE(cavium_pci_mmc, cavium_pci_mmc_supported);

I think you're not using dt?

>
> The problem I'm seeing is that in the probe function the of_offset field is
> always -1. Shouldn't it resolve this information via the compatible string
> in the device tree? How should I go about setting it up so that not only

This look strange to me, but I am assuming PCI dev hierarchy may
require u-boot,dm-pre-reloc on dt have you tried .flags =
DM_FLAG_PRE_RELOC?

thanks!
-- 
Jagan Teki
Free Software Engineer | www.openedev.com
U-Boot, Linux | Upstream Maintainer
Hyderabad, India.