usb: dwc3: changes for v3.4 merge window

Here are the changes for v3.4 merge window.

It includes a new glue layer for Samsung's Exynos platform, a simplification of
memory management on DWC3 driver by using dev_xxx functions, a few
optimizations to IRQ handling by dropping memcpy() and using bitshifts, a fix
for TI's OMAP5430 TX Fifo Allocation, two fixes on USB2 test mode
implementation (one on debugfs and one on ep0), and several minor changes such
as whitespace cleanups, simplification of a few parts of the code, decreasing a
long delay to something a bit saner, dropping a header which was included twice
and so on.

The highlight on this merge is the support for Samsung's Exynos platform,
increasing the number of different users for this driver to three.

Note that Samsung Exynos glue layer will only compile on platforms which
provide implementation for the clk API for now. Once Samsung supports
pm_runtime, that limitation can be dropped from the Makefile.

Conflicts:
	drivers/usb/dwc3/gadget.c

Define DWC3_GCTL_SCALEDOWN_MASK and use it in place of
DWC3_GCTL_SCALEDOWN(3).

Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

trivial patch, no functional changes

Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

those routines have everything we need to map/unmap
USB requests and it's better to use them.

In order to achieve that, we had to add a simple
change on how we allocate and use our setup buffer;
we cannot allocate it from coherent anymore otherwise
the generic map/unmap routines won't be able to easily
know that the GetStatus request already has a DMA
address.

Signed-off-by: Felipe Balbi <balbi@ti.com>

this will get rid of a useless memcpy on
IRQ handling, thus improving driver performance.

Tested with OMAP5430 running g_mass_storage on
SuperSpeed and HighSpeed.

Note that we are removing the little endian access
of the TRB and all accesses will be in System endianness,
if there happens to be a system in BE, bit 12 of GSBUSCFG0
should be set so that HW does byte invariant BE accesses
when fetching TRBs.

Signed-off-by: Felipe Balbi <balbi@ti.com>

When host requests us to enter a test mode,
we cannot directly enter the test mode before
Status Phase is completed, otherwise the core
will never be able to deliver the Status ZLP
to host, because it has already entered the
requested Test Mode.

In order to fix the error, we move the actual
start of Test Mode right after we receive
Transfer Complete event of the status phase.

Signed-off-by: Gerard Cauvy <g-cauvy1@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

When we set Run/Stop bit, we also move the
core to Rx.Detect state so that USB3 handshake
can start from a known location.

Signed-off-by: Felipe Balbi <balbi@ti.com>

We need to dynamically re-size TxFifos for the
cases where default values will not do.

While at that, we create a simple function which,
for now, will just allocate one full packet fifo
space for each of the enabled endpoints.

This can be improved later in order to allow for
better throughput by allocating more space for
endpoints which could make good use of that like
isochronous and bulk.

Signed-off-by: Felipe Balbi <balbi@ti.com>

Only bit 3 of the event status bitfield is valid
and the others should not be considered.

Make sure SW matches documentation on that case
to avoid bogus debugging prints which would
confuse an engineer.

Signed-off-by: Felipe Balbi <balbi@ti.com>

ep->max_streams is a mere hint to the gadget
driver that 'ep' supports stream handling. Using
that as a decision variable for enabling streams
was my worst brain-fart to date.

Instead, we should check from the Superspeed
Endpoint Companion Descriptor if the endpoint
has requested streams. For that we need a little
re-factoring but it is now correct.

Debugged-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>