45c3eb7d3a
Based on earlier discussions[1] we attempted to find a suitable location for the omap DMA header in commit 2b6c4e73 (ARM: OMAP: DMA: Move plat/dma.h to plat-omap/dma-omap.h) until the conversion to dmaengine is complete. Unfortunately that was before I was able to try to test compile of the ARM multiplatform builds for omap2+, and the end result was not very good. So I'm creating yet another all over the place patch to cut the last dependency for building omap2+ for ARM multiplatform. After this, we have finally removed the driver dependencies to the arch/arm code, except for few drivers that are being worked on. The other option was to make the <plat-omap/dma-omap.h> path to work, but we'd have to add some new header directory to for multiplatform builds. Or we would have to manually include arch/arm/plat-omap/include again from arch/arm/Makefile for omap2+. Neither of these alternatives sound appealing as they will likely lead addition of various other headers exposed to the drivers, which we want to avoid for the multiplatform kernels. Since we already have a minimal include/linux/omap-dma.h, let's just use that instead and add a note to it to not use the custom omap DMA functions any longer where possible. Note that converting omap DMA to dmaengine depends on dmaengine supporting automatically incrementing the FIFO address at the device end, and converting all the remaining legacy drivers. So it's going to be few more merge windows. [1] https://patchwork.kernel.org/patch/1519591/# cc: Russell King <linux@arm.linux.org.uk> cc: Kevin Hilman <khilman@ti.com> cc: "Benoît Cousson" <b-cousson@ti.com> cc: Herbert Xu <herbert@gondor.apana.org.au> cc: "David S. Miller" <davem@davemloft.net> cc: Vinod Koul <vinod.koul@intel.com> cc: Dan Williams <djbw@fb.com> cc: Mauro Carvalho Chehab <mchehab@infradead.org> cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de> cc: David Woodhouse <dwmw2@infradead.org> cc: Kyungmin Park <kyungmin.park@samsung.com> cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> cc: Tomi Valkeinen <tomi.valkeinen@ti.com> cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de> cc: Hans Verkuil <hans.verkuil@cisco.com> cc: Vaibhav Hiremath <hvaibhav@ti.com> cc: Lokesh Vutla <lokeshvutla@ti.com> cc: Rusty Russell <rusty@rustcorp.com.au> cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> cc: Afzal Mohammed <afzal@ti.com> cc: linux-crypto@vger.kernel.org cc: linux-media@vger.kernel.org cc: linux-mtd@lists.infradead.org cc: linux-usb@vger.kernel.org cc: linux-fbdev@vger.kernel.org Acked-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
To understand all the Linux-USB framework, you'll use these resources:
* This source code. This is necessarily an evolving work, and
includes kerneldoc that should help you get a current overview.
("make pdfdocs", and then look at "usb.pdf" for host side and
"gadget.pdf" for peripheral side.) Also, Documentation/usb has
more information.
* The USB 2.0 specification (from www.usb.org), with supplements
such as those for USB OTG and the various device classes.
The USB specification has a good overview chapter, and USB
peripherals conform to the widely known "Chapter 9".
* Chip specifications for USB controllers. Examples include
host controllers (on PCs, servers, and more); peripheral
controllers (in devices with Linux firmware, like printers or
cell phones); and hard-wired peripherals like Ethernet adapters.
* Specifications for other protocols implemented by USB peripheral
functions. Some are vendor-specific; others are vendor-neutral
but just standardized outside of the www.usb.org team.
Here is a list of what each subdirectory here is, and what is contained in
them.
core/ - This is for the core USB host code, including the
usbfs files and the hub class driver ("khubd").
host/ - This is for USB host controller drivers. This
includes UHCI, OHCI, EHCI, and others that might
be used with more specialized "embedded" systems.
gadget/ - This is for USB peripheral controller drivers and
the various gadget drivers which talk to them.
Individual USB driver directories. A new driver should be added to the
first subdirectory in the list below that it fits into.
image/ - This is for still image drivers, like scanners or
digital cameras.
../input/ - This is for any driver that uses the input subsystem,
like keyboard, mice, touchscreens, tablets, etc.
../media/ - This is for multimedia drivers, like video cameras,
radios, and any other drivers that talk to the v4l
subsystem.
../net/ - This is for network drivers.
serial/ - This is for USB to serial drivers.
storage/ - This is for USB mass-storage drivers.
class/ - This is for all USB device drivers that do not fit
into any of the above categories, and work for a range
of USB Class specified devices.
misc/ - This is for all USB device drivers that do not fit
into any of the above categories.