On 08/13/2018 04:24 AM, Bin Meng wrote: > Hi Marek, > > On Fri, Aug 10, 2018 at 8:38 PM, Marek Vasut <marek.va...@gmail.com> wrote: >> On 08/10/2018 02:01 PM, Tom Rini wrote: >>> On Wed, Aug 08, 2018 at 09:37:25PM +0200, Marek Vasut wrote: >>>> On 08/08/2018 05:32 PM, Bin Meng wrote: >>>>> Hi Marek, >>>>> >>>>> On Wed, Aug 8, 2018 at 10:33 PM, Marek Vasut <marek.va...@gmail.com> >>>>> wrote: >>>>>> On 08/08/2018 03:39 PM, Bin Meng wrote: >>>>>>> Hi Marek, >>>>>>> >>>>>>> On Wed, Aug 8, 2018 at 9:24 PM, Marek Vasut <marek.va...@gmail.com> >>>>>>> wrote: >>>>>>>> On 08/08/2018 03:14 PM, Bin Meng wrote: >>>>>>>>> Hi Marek, >>>>>>>>> >>>>>>>>> On Wed, Aug 8, 2018 at 9:03 PM, Marek Vasut <marek.va...@gmail.com> >>>>>>>>> wrote: >>>>>>>>>> The PCI controller can have DT subnodes describing extra properties >>>>>>>>>> of particular PCI devices, ie. a PHY attached to an EHCI controller >>>>>>>>>> on a PCI bus. This patch parses those DT subnodes and assigns a node >>>>>>>>>> to the PCI device instance, so that the driver can extract details >>>>>>>>>> from that node and ie. configure the PHY using the PHY subsystem. >>>>>>>>>> >>>>>>>>>> Signed-off-by: Marek Vasut <marek.vasut+rene...@gmail.com> >>>>>>>>>> Cc: Simon Glass <s...@chromium.org> >>>>>>>>>> --- >>>>>>>>>> drivers/pci/pci-uclass.c | 14 ++++++++++++++ >>>>>>>>>> 1 file changed, 14 insertions(+) >>>>>>>>>> >>>>>>>>>> diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c >>>>>>>>>> index 46e9c71bdf..306bea0dbf 100644 >>>>>>>>>> --- a/drivers/pci/pci-uclass.c >>>>>>>>>> +++ b/drivers/pci/pci-uclass.c >>>>>>>>>> @@ -662,6 +662,8 @@ static int pci_find_and_bind_driver(struct >>>>>>>>>> udevice *parent, >>>>>>>>>> for (id = entry->match; >>>>>>>>>> id->vendor || id->subvendor || id->class_mask; >>>>>>>>>> id++) { >>>>>>>>>> + ofnode node; >>>>>>>>>> + >>>>>>>>>> if (!pci_match_one_id(id, find_id)) >>>>>>>>>> continue; >>>>>>>>>> >>>>>>>>>> @@ -691,6 +693,18 @@ static int pci_find_and_bind_driver(struct >>>>>>>>>> udevice *parent, >>>>>>>>>> goto error; >>>>>>>>>> debug("%s: Match found: %s\n", __func__, >>>>>>>>>> drv->name); >>>>>>>>>> dev->driver_data = find_id->driver_data; >>>>>>>>>> + >>>>>>>>>> + dev_for_each_subnode(node, parent) { >>>>>>>>>> + phys_addr_t df, size; >>>>>>>>>> + df = ofnode_get_addr_size(node, >>>>>>>>>> "reg", &size); >>>>>>>>>> + >>>>>>>>>> + if (PCI_FUNC(df) == PCI_FUNC(bdf) && >>>>>>>>>> + PCI_DEV(df) == PCI_DEV(bdf)) { >>>>>>>>>> + dev->node = node; >>>>>>>>>> + break; >>>>>>>>>> + } >>>>>>>>> >>>>>>>>> The function pci_find_and_bind_driver() is supposed to bind devices >>>>>>>>> that are NOT in the device tree. Adding device tree access in this >>>>>>>>> routine is quite odd. You can add the EHCI controller that need such >>>>>>>>> PHY subnodes in the device tree and there is no need to modify >>>>>>>>> anything I believe. If you are looking for an example, please check >>>>>>>>> pciuart0 in arch/x86/dts/crownbay.dts. >>>>>>>> >>>>>>>> Well this does not work for me, the EHCI PCI doesn't get a DT node >>>>>>>> assigned, check r8a7794.dtsi for the PCI devices I use. >>>>>>>> >>>>>>> >>>>>>> I think that's because you don't specify a "compatible" string for >>>>>>> these two EHCI PCI nodes. >>>>>> >>>>>> That's perfectly fine, why should I specify it ? Linux has no problem >>>>>> with it either. >>>>>> >>>>> >>>>> Without a "compatible" string, DM does not bind any device in the >>>>> device tree to a driver, hence no device node created. This is not >>>>> Linux. >>>> >>>> DT is NOT Linux specific, it is OS-agnostic, DT describes hardware and >>>> hardware only. If U-Boot cannot parse DT correctly, U-Boot is broken and >>>> must be fixed. >>>> >>>> This is a fix. If there is a better fix, I am open to it. >>> >>> DT should but isn't always OS agnostic. DTS files that reside in the >>> Linux Kernel are in practice is Linux-centric with the expectation that >>> even if you could solve a given problem with valid DTS changes you make >>> whatever is parsing it do additional logic instead. That, >>> approximately, is what your patch is doing. If you added some HW >>> description information to the dtsi file everything would work as >>> expected as your DTS is describing the hardware and U-Boot is reading >>> that description and figuring out what to do with it. >> >> Yes, you need additional logic to match the PCI controller subnode in DT >> with PCI device BFD, that's expected. You do NOT need extra compatibles, >> the PCI bus gives you enough information to match a driver on them. In >> fact, adding a compatible can interfere with this matching. >> > > Please, read U-Boot's doc/driver-model/pci-info.txt. You really don't > understand current implementation in U-Boot. In short, U-Boot supports > two scenarios for PCI driver binding:
That documentation is wrong and needs to be fixed. The compatible is optional. > - Declare a PCI device in the device tree. That requires specifying a > 'compatible' string as well as 'reg' property as defined by the 'PCI > Bus Binding' spec. DM uses the 'compatible' string to bind the driver > for the device. > - Don't declare a PCI device in the device tree. Instead, using > U_BOOT_PCI_DEVICE() to declare a device and driver mapping. > > You can choose either two when you support PCI devices on your board, > but you cannot mix both support together and make them a mess. In this > patch, you hacked pci_find_and_bind_driver() which is the 2nd scenario > to support the 1st scenario. Again, the DT contains all the required information to bind the node and the driver instance. Clearly, we need option 3 for this. >>> The problem here is that in Linux, something that sees the compatible >>> renesas,pci-r8a7794 or renesas,pci-rcar-gen2 is doing whatever else >>> needs to be done. Or something else? Please explain how what you want >>> to have work here in U-Boot is working in the Linux kernel. Thanks! >> >> This has nothing to do with a specific controller. iMX6 does the same >> thing, see ie arch/arm/boot/dts/imx6q-utilite-pro.dts . >> > > Regards, > Bin > -- Best regards, Marek Vasut _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot