Randy Dunlap <rdunlap@infradead.org> reported this problem
on i386:

> drivers/built-in.o: In function `ci_hdrc_host_init':
> (.text+0x2ce75c): undefined reference to `ehci_init_driver'
>
> When USB_EHCI_HCD=m and USB_CHIPIDEA=y.

In fact, this problem is existed on all platforms which are using
chipidea driver. The root cause of this problem is the chipidea host
uses symbol exported from ehci-hcd, but chipidea core
does not depends on USB_EHCI_HCD. So, chipidea driver
will not be compiled as module if USB_EHCI_HCD=m.

It is very hard to give a perfect solution since chipidea core
depends on USB || USB_GADGET, and chipdiea host depends on
both USB_EHCI_HCD and USB_CHIPIDEA, the same problem exists for
gadget.

To fix this problem, we had to have below assumptions:

- If USB_EHCI_HCD=y && USB_GADGET=y, USB_CHIPIDEA can be 'y'.

- If USB_EHCI_HCD=m && USB_GADGET=y, USB_CHIPIDEA=m
or USB_CHIPIDEA_HOST can't be seen if USB_CHIPIDEA=y.
It will cause compile error due to no glue layer for ehci:

> error: #error "missing bus glue for ehci-hcd"

So, we had to compile USB_CHIPIDEA=m if USB_EHCI_HCD=m,
current ehci hcd core guarantee it.

- If USB_EHCI_HCD=y && USB_GADGET=m, USB_CHIPIDEA=m
or USB_CHIPIDEA_UDC can't be seen if USB_CHIPIDEA=y.
Of cos, the gadget will out of working at this situation,
so the user had to compile USB_CHIPIDEA=m.

- USB_EHCI_HCD=m && USB_GADGET=m, we can't see
USB_CHIPIDEA_HOST and USB_CHIPIDEA_UDC unless
USB_CHIPIDEA=m.

The reason why it has above assumptions:
- If both ehci core and gadget core build as module,
the chipidea has to build as module.
- If one of ehci core or gadget core is built in, another
is built as module, we can only enable the function which
is built in, or enable both roles as modules (USB_CHIPIDEA=m),
since chipidea core driver takes care of both host and device roles.
Signed-off-by: NPeter Chen <peter.chen@freescale.com>
Signed-off-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fixes link error when USB_EHCI_HCD=m and USB_CHIPIDEA_HOST=y:

	drivers/built-in.o: In function `ci_hdrc_host_init':
	drivers/usb/chipidea/host.c:104: undefined reference to `ehci_init_driver'

as a result of commit 09f6ffde ("USB: EHCI: fix build error by making
ChipIdea host a normal EHCI driver").

Cc: stable@vger.kernel.org [v3.7+]
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch (as1627) splits the ehci-hcd core code, which has become a
separate library module, out from the ChipIdea host driver.  Instead
of #include-ing ehci-hcd.c directly, the ChipIdea module will now use
the ehci-hcd library in a normal fashion.

This fixes a build error caused by commit
3e023203 (USB: EHCI: prepare to make
ehci-hcd a library module); I had forgotten about the unorthodox way
the ChipIdea driver uses the ehci-hcd code.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Acked-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This commit removes USB_GADGET_DUALSPEED and USB_GADGET_SUPERSPEED
Kconfig options.  Since now kernel allows many UDC drivers to be
compiled, those options may turn to no longer be valid.  For
instance, if someone decides to build UDC that supports super
speed and UDC that supports high speed only, the latter will be
"assumed" to support super speed since USB_GADGET_SUPERSPEED will
be selected by the former.

The test of whether CONFIG_USB_GADGET_*SPEED was defined was just
an optimisation which removed otherwise dead code (ie. if UDC is
not dual speed, there is no need to handle cases that can happen
if speed is high).  This commit removes those checks.
Signed-off-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

Since commit "5e0aa49e usb: chipidea: use generic map/unmap routines",
the udc part of the chipidea driver needs the generic usb gadget helper
functions. If the chipidea driver with udc support is built into the
kernel and usb gadget is built a module, the linking of the kernel
fails with:

drivers/built-in.o: In function `_hardware_dequeue':
drivers/usb/chipidea/udc.c:527:
    undefined reference to `usb_gadget_unmap_request'
drivers/usb/chipidea/udc.c:1269:
    undefined reference to `usb_gadget_unmap_request'
drivers/usb/chipidea/udc.c:1821:
    undefined reference to `usb_del_gadget_udc'
drivers/usb/chipidea/udc.c:443:
    undefined reference to `usb_gadget_map_request'
drivers/usb/chipidea/udc.c:1774:
    undefined reference to `usb_add_gadget_udc'

This patch changes the dependencies, so that udc support can only be
activated if the linux gadget support (USB_GADGET) is builtin or both
chipidea driver and USB_GADGET are modular. Same dependencies for the
chipidea host support and the linux host side USB support (USB).

While there, fix the indention of chipidea the help text.

Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

ci13xxx host needs Root Hub Transaction Translators.
Reported-by: NShawn Guo <shawn.guo@freescale.com>
Signed-off-by: NRichard Zhao <richard.zhao@freescale.com>
Acked-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
Acked-by: NMarek Vasut <marex@denx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This adds EHCI host support to the chipidea driver. We want it to be
part of the hdrc driver and not a standalone (sub-)driver module, as
the structure of ehci-hcd.c suggests, so for chipidea controller we
hack it to not provide platform-related code, but only the ehci hcd.

The ehci-platform driver won't work for us here too, because the
controller uses the same registers for both device and host mode and
also otg-related bits, so it's not really possible to put ehci registers
into a separate resource.

This is not a pretty solution, but the alternative is exporting symbols
from the chipidea driver to a ehci-chipidea driver and doing all the
module refcounting.
Signed-off-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Split the driver into the following parts:
  * core  -- resources, register access, capabilities, etc;
  * udc   -- device controller functionality;
  * debug -- logging events.
Signed-off-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since chipidea is a dual role controller, it makes sense to move it
to its own directory, where we can also have host, otg and platform
code related to this controller. It also makes sense to break out
the driver into several compilation units like udc, host, debugging
code, etc.

Firstly, let's move the udc and platform code to drivers/usb/chipidea.
Signed-off-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>