usb: xhci-hcd: replace opencoded non-atomic 64-bit MMIO with lo_hi helper ...

Commit 3c5317e9046 ("usb: xhci-hcd: Make use of lo_hi_readq/writeq()")
had made use of lo_hi_readq/writeq() to implement xhci_read/write_64(),
like Linux does, but this was removed in commit fddd1c7c51a8
("usb: host: remove xhci driver"). Reinstate it to make code clearer.

No functional change.

[Note: Linux doesn't use any readq/writeq, but does two 32-bit access
 always, even on 64-bit systems]

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

usb: xhci-hcd: remove unused #include <asm/cache.h> ...

We don't use anything defined within, so drop it.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

usb: Add U-Boot xhci driver ...

This adds the xhci driver from U-Boot-2020.04-rc2. The usual things
like adjusting to the barebox driver model and using dev_* instead of
printf/puts/debug messages are made.

The previously existing PCI support is not present in this driver
currently. XHCI PCI support was not enabled in any defconfig, so we
boldly assume it was unused. It shouldn't be much effort though to
add it again.

The memory handling has been changed for barebox. The various
descriptor rings and descriptors are allocated with dma_alloc_coherent()
which makes the cache flushing/invalidating unnecessary. They are left
in the driver in case we want to change that.

The XHCI has a nasty limitation in that the TRBs may not cross a 64KiB
boundary. This limitation has been handled in the U-Boot driver, but the
handling seems to be broken. We help ourselves with using a bounce
buffer which is sufficiently aligned, but this limits the maximum bulk
transfer size to 64KiB.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

usb: host: remove xhci driver ...

The current xhci driver support USB 2.0 only. The U-Boot driver is better
developed and supports USB 3.0 devices. Remove the xhci driver first as
a separate patch to make the patch adding the new U-Boot based driver
better readable.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

usb: xhci-hcd: Make use of lo_hi_readq/writeq() ...

Make use of lo_hi_readq/writeq() to implement xhci_read/write_64()
helpers, same as it is done in the Linux kernel.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

usb: xhci-hcd: Drop 'dma' field from struct xhci_hcd ...

Drop 'dma' field from struct xhci_hcd since it is not really used
anywhere.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

usb: xhci-hcd: Add support for 64-byte context size ...

xHCI spec allows for various context to be either 32 or 64 bytes in
size, so we can't rely on struct definitions to correctly reflect data
layout. Port varios context accessors from Linux kernel and convert
the rest of the code to use them in order to be able to support both
context sizes.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

USB: host: add xHCI HCD, Hub, and platform driver ...

This adds support for xHCI USB 3.0 host controllers found on various
SoCs and PCI devices. Currently, the driver only supports the virtual
USB 2.0 ports of the host controller, so if you plan to use USB 3.0
devices, put a USB 2.0 cable in between.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>