On 08/09/2018 01:24 AM, Bin Meng wrote:
Hi Marek,
On Thu, Aug 9, 2018 at 3:37 AM, Marek Vasut marek.vasut@gmail.com 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.vasut@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.vasut@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.vasut@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+renesas@gmail.com >> Cc: Simon Glass sjg@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.
Sorry this is a hack to current U-Boot implementation, not fix.
I am waiting for a better solution or suggestion ...
The fix should be adding "ehci-pci" compatible string in the r8a7794.dtsi.
Wrong. The DT is perfectly valid as is.
The device sitting at a particular slot/function can very well be ie. xhci controller and the DT node would be valid for it too, unless you enforce a compatible, which will mess things up.
Each PCI device already has a PCI ID and class which is used to identify it and based on which the drivers bind to it, so a DT compatible is NOT needed and is actually redundant and harmful.
What is needed here is to assign a valid DT node to a driver instance of a PCI device if such a matching node exists in DT and that is all this patch does.
I disagree DT is OS-agnostic. This are lots of stuff in DT that are OS-specific. eg: there are lots of bindings in DT that requires Linux's device driver framework to work with.
This logic is flawed. If there exists a binding which depends on some behavior of specific OS then the binding is likely wrong. That specifically does not imply DT is OS-specific. Again, it is not and that is by design. The DT must be usable by multiple OSes with very different internal design, Solaris, *BSD, Linux, U-Boot to name a few.
As you said, DT is just a standard to describe hardware and hardware only. But there are various methods to describe hardware in DT that's why we have a proper defined bindings in Linux.
defined bindings, yes. In Linux ... no ... the HW is OS-independent, so is it's description in DT.
How OS parses and utilizes these information is completely on their own.
Regards, Bin