docs: usb: rename files to .rst and add them to drivers-api

While there are a mix of things here, most of the stuff
were written from Kernel developer's PoV. So, add them to
the driver-api book.

A follow up for this patch would be to move documents from
there that are specific to sysadmins, adding them to the
admin-guide.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Johan Hovold <johan@kernel.org>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 0 insertions, 53 deletions

diff --git a/Documentation/usb/dwc3.txt b/Documentation/usb/dwc3.txt
deleted file mode 100644
index f94a7ba16573..000000000000
--- a/Documentation/usb/dwc3.txt
+++ /dev/null
@@ -1,53 +0,0 @@
-===========
-DWC3 driver
-===========
-
-
-TODO
-~~~~
-
-Please pick something while reading :)
-
-- Convert interrupt handler to per-ep-thread-irq
-
-  As it turns out some DWC3-commands ~1ms to complete. Currently we spin
-  until the command completes which is bad.
-
-  Implementation idea:
-
-  - dwc core implements a demultiplexing irq chip for interrupts per
-    endpoint. The interrupt numbers are allocated during probe and belong
-    to the device. If MSI provides per-endpoint interrupt this dummy
-    interrupt chip can be replaced with "real" interrupts.
-  - interrupts are requested / allocated on usb_ep_enable() and removed on
-    usb_ep_disable(). Worst case are 32 interrupts, the lower limit is two
-    for ep0/1.
-  - dwc3_send_gadget_ep_cmd() will sleep in wait_for_completion_timeout()
-    until the command completes.
-  - the interrupt handler is split into the following pieces:
-
-    - primary handler of the device
-      goes through every event and calls generic_handle_irq() for event
-      it. On return from generic_handle_irq() in acknowledges the event
-      counter so interrupt goes away (eventually).
-
-    - threaded handler of the device
-      none
-
-    - primary handler of the EP-interrupt
-      reads the event and tries to process it. Everything that requires
-      sleeping is handed over to the Thread. The event is saved in an
-      per-endpoint data-structure.
-      We probably have to pay attention not to process events once we
-      handed something to thread so we don't process event X prio Y
-      where X > Y.
-
-    - threaded handler of the EP-interrupt
-      handles the remaining EP work which might sleep such as waiting
-      for command completion.
-
-  Latency:
-
-   There should be no increase in latency since the interrupt-thread has a
-   high priority and will be run before an average task in user land
-   (except the user changed priorities).