When the Broadcom STB PCIe controller is initialized, it must be set
into one of three CLKREQ# modes: "none"/"aspm"/"l1ss". The Linux driver,
through today, hard-codes "aspm" since the vast majority of boards using
this driver have a fixed PCIe bus with the CLKREQ# signal wired up.
The Raspberry Pi CM4, however, can be connected to a plethora of PCIe
devices, some of which do not connect the CLKREQ# line (they just leave
it floating). So "aspm" mode is no longer appropriate in all cases. In
Linux, there is a proposed patchset [1] to determine the proper mode.
This doesn't really make sense in U-Boot's case, so we just change the
assumption from "aspm" to "none" (which is always safe).
This patch DOES resolve a real-world crash that occurs when U-Boot is
running on a Raspberry Pi CM4 installed in slot 3 of a Turing Pi 2
cluster board.
[1]: https://lore.kernel.org/all/20230428223500.23337-1-jim2101024@gmail.com/
Signed-off-by: Sam Edwards <CFSworks@gmail.com>
Since the initial U-Boot driver was ported here from Linux, the latter
has had a few changes for robustness/stability. This patch brings over
two of them:
- Do not attempt to access the configuration space of a PCIe device if
the link has gone down, as that will result in an asynchronous SError
interrupt which will crash U-Boot.
- Wait for the recommended 100ms after PERST# is deasserted.
I sent this patch while debugging a crash involving PCIe, but these
are unrelated improvements. I do not believe that this patch fixes any
real-world bug.
Signed-off-by: Sam Edwards <CFSworks@gmail.com>
So far we've assumed a fixed configuration for inbound windows as we had
a single user for this controller. But the controller's DMA constraints
were improved starting with BCM2711's B1 revision of the SoC, notably
available in CM4 and Pi400. They allow for wider inbound windows. We can
now cover the whole address space, whereas before we where limited to
the lower 3GB.
This information is passed to us through DT's 'dma-ranges' property and
it's specially important for us to honor it since some interactions with
the board's co-processor assume we're doing so (specifically the XHCI
firmware load operation, which is handled by the co-processor after
u-boot has correctly configured the PCIe controller).
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Tested-by: Peter Robinson <pbrobinson@gmail.com>
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
Make sure we handover the PCIe controller in a clean state. Some of the
devices hanging from the PCIe bus might need to be properly reset
through #PERST in order for Linux to be able to initialize them.
This is specially important in order to properly initialize Raspberry Pi
4 B and 400's USB chip.
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
This name is far too long. Rename it to remove the 'data' bits. This makes
it consistent with the platdata->plat rename.
Signed-off-by: Simon Glass <sjg@chromium.org>
This construct is quite long-winded. In earlier days it made some sense
since auto-allocation was a strange concept. But with driver model now
used pretty universally, we can shorten this to 'auto'. This reduces
verbosity and makes it easier to read.
Coincidentally it also ensures that every declaration is on one line,
thus making dtoc's job easier.
Signed-off-by: Simon Glass <sjg@chromium.org>
This patch adds basic driver PCI Express controller found on Broadcom
set-top-box SoCs, e.g. BCM2711.
The code is based on Linux upstream driver (pcie-brcmstb.c) with MSI
handling removed. The inbound access memory region is not currently
parsed from dma-ranges DT property and a fixed 3GB region is used.
The patch has been tested on RPI4 board, i.e. on BCM2711 SoC with VL805
USB Host Controller.
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
