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>

treewide: remove references to CREDITS ...

The CREDITS file was removed from barebox in 2015 by commit 6570288f2d97
("Remove the CREDITS file"). Remove references to it from several files.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Merge branch 'for-next/usb'

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: host: ehci: distinguish DMA addresses ...

This patch adds translation from CPU to DMA addresses, which is required for
proper operation on certain architectures like MIPS.

This patch also fixes the bug introduced by 4350744bf5 "usb: ehci-hcd: port
periodic transactions implementation from the u-boot", which is still present
in the original U-Boot code:

	td->qt_buffer[0] =
		cpu_to_hc32((unsigned long)buffer + i * elementsize);
	td->qt_buffer[1] =
		cpu_to_hc32((td->qt_buffer[0] + 0x1000) & ~0xfff);
	...

In case of a big-endian CPU 0x1000 is added to the byte-swapped value
`td->qt_buffer[0]`, the result is byte swapped once again and stored to
`td->qt_buffer[1]`. This results in erroneous values being stored in
`td->qt_buffer[1..4]`.

N.B.: This patch needs some testing on architectures different from MIPS.

Signed-off-by: Peter Mamonov <pmamonov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Merge branch 'for-next/rpi'

usb: ehci: Do not use memset on dma coherent memory ...

memset is an optimized operation that at least on ARM64 may only be
called on cached memory, see 32e8842c40 ("ARM: lib64: Make string
functions aware of MMU configuration"). To avoid crashes in the ehci
driver we no longer call memset on memory allocated with
dma_alloc_coherent(), but use a simple memzero32 function instead.

Reported-by: Elmar Albert <EAlbert@data-modul.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

usb: Add dwc2 host driver ...

This adds a driver for the dwc2 controller in host mode. The driver is
taken from U-Boot-2019.10 and tested on a Raspberry Pi 3.

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

Merge branch 'for-next/usb-ehci'

usb: ohci: Add dependency on HAS_DMA ...

OHCI driver uses varios DMA API functions (dma_alloc_coherent()
et. al), so add dependency on HAS_DMA to indicate that.

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

usb: ohci-hcd: Do not zero out DMA coherent memory ...

Memory returned by dma_alloc_coherent() should already be zeroed
out, so there's no need to do this explicitly.

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

usb: host: ehci: Allocate only NUM_QH queue heads for qh_list ...

Use NUM_QH, not NUM_TD to specify allocation size.

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

ush: host: ehci: Simplify QH initialization in ehci_submit_async() ...

We use a fixed circular list for asynchronous schedule that never
changes, so if we drop an explicit memset() that zeros out an entire
struct and replace it with code initializine all of the fields
explicitly, we can set QH list once in ehci_init() and never touch it
again.

While at it move qt_altnext initialization to ehci_init() as well
since we never change that field either.

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

usb: host: ehci: Treat ehci->qh_list as an array ...

Since ehci->qh_list is an array, convert the code to use
ehci->qh_list[0] to access its first element to make things a bit more
clear. No functional change intended.

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

usb: host: ehci: Drop explicit memset() in ehci_init() ...

Memory allocated by dma_alloc_coherent() is already zeroed out,
ehci->qh_list[0] never changes during the operation of the driver and
ehci->qh_list[1] will be explicitly initialized by ehci_submit_async()
so this additional memset() shouldn't be necessary.

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

usb: host: ehci: Replace explicit printf() with dev_err() ...

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

usb: host: ehci: Add a comment explaing IOC setting for data ...

Add a comment explaining the rationale behinde QT_TOKEN_IOC(req ==
NULL).

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

usb: host: ehci: Use bool to simplify ehci_submit_async() ...

Change the type of 'c' to bool and drop the trigrah.

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

usb: host: ehci: Drop needless assignments in ehci_submit_async() ...

Neither of those is necessary, since both will be overwritten further
down in the code.

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

usb: host: ehci: Simplify ehci_submit_async()'s epilogue ...

Re-organize the epilogue of ehci_submit_async() to bail out early if
token is still marked as "active" and drop no longer necessary check
for "dev->status != USB_ST_NOT_PROC". While at it return -EIO instead
of -1 in the case of error.

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

usb: host: ehci: Initialize qTDs explicitly ...

Convert the code to initialize only used qTDs as well as initializing
all of the fields explicitly without doing a wholesale memset() first.

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

usb: host: ehci: Simplify ehci_td_buffer() ...

Rework the code of ehci_td_buffer() with following trivial changes:

    * Switch to using dma_addr_t for 'delta' and 'next'
    * Convert while to for loop
    * Replace explicit magic number with dedicated contants derived
      via ARRAY_SIZE
    * Use ALIGN_DOWN to calculate 'next'
    * Return -ENOMEM instead of -1 when we ran out of buffers

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

usb: host: ehci: Simplify qTD buffer synchronization ...

Only two buffers ever need to be sychronized and DMA direction of it
is always known based on the type of request we are
processing. Simplify the code by moving synchronization to be a part
of ehci_prepare_qtd(). While at it convert the code to use
dma_map_single() API.

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

usb: host: ehci: Introduce ehci_prepare_qtd() ...

Move shared struct qTD initialization code into a subroutine and
convert the rest of the code to use it. No functional change intended.

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

usb: host: ehci: Drop unnecessary cleanup code ...

This looks like a leftover from U-Boot. Analogous code there would
walk all qTDs and call ehci_free() on each one of them, but since we
don't have anything of the sort it seems the whole loop can be
dropped. Note that U-Boot dropped that code in
de98e8b

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

usb: host: ehci: Replace magic number with macros ...

Import a number of missing macros from U-Boot and convert ehci-hcd to
use them instead of explicitly specifying magic shifts. No functional
change intended.

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

usb: host: ehci: Use to USBSTS to wait for transfer completion ...

Since we already set up our last qTD to have IOC flag set we may as
well take advange of that and poll USBSTS to wait for transfer
completion. Doesn't change much, but allows us to drop a custom
polling loop and re-use handshake() instead.

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

usb: host: ehci: Share code to enable/disable async schedule ...

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