We know that we have to iterate over the list of
started requests. Instead of looping forever, we can
rely on list_for_each_entry(). Likewise, instead of
a do {} while loop over all, maybe available,
scatterlist entries, we can detect if $this request
uses scatterlist and rely on for_each_sg().

This makes the code easier to follow while making
sure that we will *always* break out of the loop.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Many of the comments in that function are really
outdated and don't match what the driver is
doing. Moreover, recent patches combined programming
model for all non-control endpoints, this gives us
an opportunity to get rid of our special cases in
__dwc3_gadget_ep_queue().
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

We always need to decrement our index by at least
one. Simplify the implementation by using a
temporary local variable and making sure that we
will always decrement one extra if tmp == 0.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Instead of waiting until giveback before
incrementing the dequeue pointer, we can increment
it from dwc3_cleanup_done_reqs(), that way we avoid
an extra loop over all TRBs during giveback.

While at that, also avoid using req->first_trb_index
as that's completely unnecessary. A follow-up patch
will clean up further uses of that and remove the
field altogether.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

The only endpoint which actually requires LST bit
and XferComplete is ep0/1. Let's save some time by
completely removing LST bit support and
XferComplete.

This simplifies and consolidates endpoint handling
for all other 3 transfer types while also avoiding
extra interrupts.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

stop consuming TRBs when we reach one with HWO bit
already set. This will prevent us from prematurely
retiring a TRB.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

According to Synopsys Databook 2.60a, section 8.3.4,
it's stated that:

	The LST bit should be set to 0 (isochronous
	transfers normally continue until the
	endpoint is removed entirely, at which time
	an End Transfer command is used to stop the
	transfer).

This patch makes sure that detail is observed and
fixes a regression with Android Audio playback
caused by recent changes to DWC3 gadget.
Signed-off-by: NJanusz Dziedzic <januszx.dziedzic@linux.intel.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

If we stop earlier due to short packet, we will
not be able to giveback all TRBs.

Cc: <stable@vger.kernel.org>
Cc: Brian E Rogers <brian.e.rogers@intel.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

DWC3 has one interesting peculiarity with chained
transfers. If we setup N chained transfers and we
get a short packet before processing all N TRBs,
DWC3 will (conditionally) issue a XferComplete or
XferInProgress event and retire all TRBs from the
one which got a short packet to the last without
clearing their HWO bits.

This means SW must clear HWO bit manually, which
this patch is doing.

Cc: <stable@vger.kernel.org>
Cc: Brian E Rogers <brian.e.rogers@intel.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

When using SG lists, we would end up setting
request->actual to:

	num_mapped_sgs * (request->length - count)

Let's fix that up by incrementing request->actual
only once.

Cc: <stable@vger.kernel.org>
Reported-by: NBrian E Rogers <brian.e.rogers@intel.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

It had changed to be suspend event for BIT6 in DEVT register from
version 2.30a and above. Thus this patch introduces one suspend
event handler to handle the suspend event.
Signed-off-by: NBaolin Wang <baolin.wang@linaro.org>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Implementations might use different IRQs for
host, gadget so use named interrupt resources
to allow device tree to specify the interrupts.

Following are the interrupt names

Peripheral Interrupt - peripheral
HOST Interrupt - host

Maintain backward compatibility for a single named
interrupt ("dwc3_usb3") for all interrupts as well as
unnamed interrupt at index 0 for all interrupts.

As platform_get_irq() variants are used, tackle
the -EPROBE_DEFER case as well.
Signed-off-by: NRoger Quadros <rogerq@ti.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

It will be crash to stop gadget when the dwc3 device had been into suspend
state, thus we need to check if the dwc3 device had been into suspend state
when UDC try to stop gadget.
Signed-off-by: NBaolin Wang <baolin.wang@linaro.org>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Because of recent changes to transfer handling on
DWC3, we will not get XferComplete unless we
completely fill up our TRB ring. This means that we
might get a Reset or Disconnect without getting a
XferComplete first.

In order to correctly release our allocated Transfer
Resource, we must issue ENDTRANSFER command whenever
dep->resource_index is valid.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

it's clear now that when is_on=true, we must loop
until DWC3_DSTS_DEVCTRLHLT clears; while when
is_on=false we must loop until DWC3_DSTS_DEVCTRLHLT
gets set.

Instead of adding actual if() statements, we can
rely on XOR operation to evaluate to true only when
the above conditions apply. Then, we can move the
break condition back to the while() statement
together with our timeout check and the resulting
code is very compact and simpler to read.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

instead of looping forever and forcing a return if
timeout reaches zero, we can just use timeout and
loop's break condition directly.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

testing shows that udelay() is unnecessary as
controller reaches Halted state almost
instantenously as can be seen by our timeout
variable never actually decrementing.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

'modify' is what the current action is called. Let's
rename it so it matches databook. While at that,
also make sure to add support 'init' action too.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

If we don't, we will overwrite valid TRBs.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Now we can try to issue Update Transfer every time
gadget driver queues a new request. This will make
sure we keep controller's queue busy for as long as
possible.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

We don't need this IRQ anymore for interrupt or bulk
endpoints.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Let's only set LST bit when we run out of space in
our TRB ring. For all other cases, we keep LST bit
unset which will prevent constant allocation and
deallocation of endpoint transfer resources.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Instead of relying on empty list of queued requests,
let's rely on the fact that we have a TRB being
processed right now.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

We will be using this information to change how we
figure out when we need LST bit. For now, just
update our counters.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

According to SNPS databook, we need to pass transfer
resource on update transfer command, let's do it.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

when passing strings to trace, we don't need the
trailing newline character. Trace already appends a
newline character automatically.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Correct the use of the DWC3_DSTS_XXX_SPEED and DWC3_DCFG_XXX_SPEED
macros. The wrong set of macros were being used in a few places.

This is only a cosmetic change as the values for both sets are
identical.
Signed-off-by: NJohn Youn <johnyoun@synopsys.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

From sparse:
warning: cast truncates bits from constant value (100 becomes 0)

The DWC3_TRB_NUM constant is too big for u8. Do the calculation a
slightly different way that should still be optimized out for the case
where DWC3_TRB_NUM == 256.
Signed-off-by: NJohn Youn <johnyoun@synopsys.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

If the trb->enqueue == trb->dequeue, then it could be full or empty.
This could also happen at TRB index 0, so modify the check to handle
that condition. At index 0, the previous TRB is the one just before the
link TRB.
Signed-off-by: NJohn Youn <johnyoun@synopsys.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

The TRBs left calculation didn't account for the link TRB taking up one
spot.

If the trb_dequeue < trb_enqueue, then the result includes the link
TRB slot so it must be adjusted.
Signed-off-by: NJohn Youn <johnyoun@synopsys.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

The current calculation takes dep->trb_dequeue - dep->trb_enqueue to
find the TRB space left.

If you enqueue 1, that results in:
(u8) 0 - (u8) 1 = 0xff = 255 TRBs left.

This is correct if DWC3_TRB_NUM == 256.

If DWC3_TRB_NUM is less than 256 (but still a power of 2) you need to
mod the result by DWC3_TRB_NUM.

For example the same calculation with DWC3_TRB_NUM = 8, results in:
255 % 6 = 7 TRBs left.
Signed-off-by: NJohn Youn <johnyoun@synopsys.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

If trbs_left == 0, we don't have any space left in the TRB ring so don't
prepare anything.
Signed-off-by: NJohn Youn <johnyoun@synopsys.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Clears out all the TRBs in the ring to clean up any stale data that
might be in them from the previous time the endpoint was enabled.

Also removed the existing clear of the LINK trb since the entire ring is
cleard just before.
Signed-off-by: NJohn Youn <johnyoun@synopsys.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Make the skipping of the link TRBS built-in to the increment operation.
This simplifies the code wherever we increment the trb index and ensures
that we never end up pointing to a link trb.
Signed-off-by: NJohn Youn <johnyoun@synopsys.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Cleans up the sparse warning:
warning: dubious: x | !y

Since we do want a bitwise OR here, don't use a logical (true/false)
value. Probably is not a real issue but it cleans up the warning.
Signed-off-by: NJohn Youn <johnyoun@synopsys.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Just like we did for endpoint commands, let's have a
single trace output for the command and its
status. This will improve trace readability
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

We want commands to finish ASAP, so let's remove
that udelay() call.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Just like we did for endpoint commands, let's use a
single return point for generic commands as
well. This aids readability.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Instead of printing command's status with a separate
trace printout, let's print it within a single call.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

instead of having infinite loop and always checking
timeout value as a break condition, we can just
decrement timeout inside while's condition.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>