This patch adds asynchronous I/O support for FunctionFS endpoint files.
It adds ffs_epfile_aio_write() and ffs_epfile_aio_read() functions responsible
for preparing AIO operations.

It also modifies ffs_epfile_io() function, adding aio handling code. Instead
of extending list of parameters of this function, there is new struct
ffs_io_data which contains all information needed to perform I/O operation.
Pointer to this struct replaces "buf" and "len" parameters of ffs_epfile_io()
function. Allocated buffer is freed immediately only after sync operation,
because in async IO it's freed in complete funcion. For each async operation
an USB request is allocated, because it allows to have more than one request
queued on single endpoint.

According to changes in ffs_epfile_io() function, functions ffs_epfile_write()
and ffs_epfile_read() are updated to use new API.

For asynchronous I/O operations there is new request complete function named
ffs_epfile_async_io_complete(), which completes AIO operation, and frees
used memory.
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

This patch adds poll function for file representing ep0.

Ability of read from or write to ep0 file is related with actual state of ffs:
- When desctiptors or strings are not written yet, POLLOUT flag is set.
- If there is any event to read, POLLIN flag is set.
- If setup request was read, POLLIN and POLLOUT flag is set, to allow
  send response (by performing I/O operation consistent with setup request
  direction) or set stall (by performing I/O operation opposite  setup
  request direction).
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

This patch fixes __ffs_ep0_queue_wait() function, which now returns number of
bytes transferred in USB request or error code in case of failure. This is
needed by ffs_ep0_read() function, when read data is copied to userspace.

It also cleans up code by removing usused variable ep0req_status.
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

The FFS_SETUP_STATUS macro could be trivialy replaced with an static
inline function but more importantly its name was tad confusing.
The name suggested it was a simple accessor macro but it actually
did change the state of the ffs_data structure perfomring
a FFS_SETUP_CANCELLED -> FFS_NO_SETUP transition.  The name of the
function -- ffs_setup_state_clear_cancelled -- should better
describe what the function actually does.
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

Since “cancelled” is spelled with two “l”s, rename FFS_SETUP_CANCELED
to FFS_SETUP_CANCELLED.
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

Consistently prefix function name with underscore if the function has to
be called with ffs_lock taken.
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

ffs_alloc_dev and ffs_free_dev are used only in f_fs.c,
so make them static.
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

Remove trailing whitespace
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

ffs_dev->ffs_release_dev_callback should be accessed only if ffs_dev
is not NULL.
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

Replace kzalloc by devm_kzalloc and remove the kfree() calls.
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>

devm_ioremap_resource does sanity checks on the given resource. No need to
duplicate this in the driver.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>

When s3c_hsotg_ep_sethalt() function is called for ep0 it should be stalled
in the same way that it is in s3c_hsotg_process_control() function, because
SET_HALT for ep0 is delayed response for setup request. Endpoint 0, if
halted, it doesn't need CLEAR_HALT because it clears "stalled" state
automatically when next setup request is received.

For this reason this patch moves code setting ep0 to "stalled" state to new
function named s3c_hsotg_stall_ep0() which is called in
s3c_hsotg_process_control() function as an immediate response for setup
request, and in s3c_hsotg_ep_sethalt() function as a delayed response for
setup request.
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

When read data from g_printer, we see a Segmentation fault. eg:

Unable to handle kernel paging request at virtual address bf048000 pgd
= cf038000 [bf048000] *pgd=8e8cf811, *pte=00000000, *ppte=00000000
Internal error: Oops: 7 [#1] PREEMPT ARM Modules linked in: bluetooth
rfcomm g_printer
CPU: 0    Not tainted  (3.4.43-WR5.0.1.9_standard #1)
PC is at __copy_to_user_std+0x310/0x3a8 LR is at 0x4c808010
pc : [<c036e990>]    lr : [<4c808010>]    psr: 20000013
sp : cf883ea8  ip : 80801018  fp : cf883f24
r10: bf04706c  r9 : 18a21205  r8 : 21953888
r7 : 201588aa  r6 : 5109aa16  r5 : 0705aaa2  r4 : 5140aa8a
r3 : 0000004c  r2 : 00000fdc  r1 : bf048000  r0 : bef5fc3c
Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
Control: 10c5387d  Table: 8f038019  DAC: 00000015 Process
g_printer_test. (pid: 661, stack limit = 0xcf8822e8)
Stack: (0xcf883ea8 to 0xcf884000)
3ea0:                   bf047068 00001fff bef5ecb9 cf882000 00001fff bef5ecb9
3ec0: 00001fff 00000000 cf2e8724 bf044d3c 80000013 80000013 00000001
bf04706c
3ee0: cf883f24 cf883ef0 c012e5ac c0324388 c007c8ac c0046298 00008180
cf29b900
3f00: 00002000 bef5ecb8 cf883f68 00000003 cf882000 cf29b900 cf883f54
cf883f28
3f20: c012ea08 bf044b0c c000eb88 00000000 cf883f7c 00000000 00000000
00002000
3f40: bef5ecb8 00000003 cf883fa4 cf883f58 c012eae8 c012e960 00000001
bef60cb8
3f60: 000000a8 c000eb88 00000000 00000000 cf883fa4 00000000 c014329c
00000000
3f80: 000000d4 41af63f0 00000003 c000eb88 cf882000 00000000 00000000
cf883fa8
3fa0: c000e920 c012eaa4 00000000 000000d4 00000003 bef5ecb8 00002000
bef5ecb8
3fc0: 00000000 000000d4 41af63f0 00000003 b6f534c0 00000000 419f9000
00000000
3fe0: 00000000 bef5ecac 000086d9 41a986bc 60000010 00000003 0109608a
0088828a
Code: f5d1f07c e8b100f0 e1a03c2e e2522020 (e8b15300) ---[ end trace
97e2618e250e3377 ]--- Segmentation fault

The root cause is the dev->rx_buffers list has been broken.
When we call printer_read(), the following call tree is triggered:

printer_read()
	|
	+---setup_rx_reqs(req)
	|	|
	|	+---usb_ep_queue(req)
	|	|	|
	|	|	+---...
	|	|		|
	|	|		+---rx_complete(req).
	|	|
	|	+---add the req to dev->rx_reqs_active
	|
	+---while(!list_empty(&dev->rx_buffers)))

The route happens when we don't use DMA or fail to start DMA in USB
driver. We can see: in the case, in rx_complete() it will add the req
to dev->rx_buffers. meanwhile we see that we will also add the req to
dev->rx_reqs_active after usb_ep_queue() return, so this adding will
break the dev->rx_buffers out.

After, when we call list_empty() to check dev->rx_buffers in while(),
due to can't check correctly dev->rx_buffers, so the Segmentation fault
occurs when copy_to_user() is called.
Signed-off-by: wenlin.kang <wenlin.kang@windriver.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

The problem occurs in follow path.

printer_read()
	|
	+---setup_rx_reqs()
		|
		+---usb_ep_queue()
			|
			+---...
				|
				+---rx_complete()

Although it is clear from code, we can't get it normally.
only when we enable some spin_lock debug config option, we can find it.
eg:
BUG: spinlock lockup on CPU#0, g_printer_test_/584
 lock: bf05e158, .magic: dead4ead, .owner: g_printer_test_/584, .owner_cpu: 0
[<c0016e1c>] (unwind_backtrace+0x0/0x104) from [<c067aef8>] (dump_stack+0x20/0x24)
[<c067aef8>] (dump_stack+0x20/0x24) from [<c0680bec>] (spin_dump+0x8c/0x94)
[<c0680bec>] (spin_dump+0x8c/0x94) from [<c039071c>] (do_raw_spin_lock+0x128/0x154)
[<c039071c>] (do_raw_spin_lock+0x128/0x154) from [<c0685618>] (_raw_spin_lock_irqsave+0x64/0x70)
[<c0685618>] (_raw_spin_lock_irqsave+0x64/0x70) from [<bf05b4e8>] (rx_complete+0x54/0x10c [g_printer])
[<bf05b4e8>] (rx_complete+0x54/0x10c [g_printer]) from [<c0480478>] (musb_g_giveback+0x78/0x88)
[<c0480478>] (musb_g_giveback+0x78/0x88) from [<c048060c>] (rxstate+0xa0/0x10c)
[<c048060c>] (rxstate+0xa0/0x10c) from [<c0480d50>] (musb_ep_restart+0x44/0x70)
[<c0480d50>] (musb_ep_restart+0x44/0x70) from [<c0480fe4>] (musb_gadget_queue+0xe8/0xf8)
[<c0480fe4>] (musb_gadget_queue+0xe8/0xf8) from [<bf05b2b0>] (setup_rx_reqs+0xa4/0x178 [g_printer])
[<bf05b2b0>] (setup_rx_reqs+0xa4/0x178 [g_printer]) from [<bf05bb58>] (printer_read+0x9c/0x3f4 [g_printer])
[<bf05bb58>] (printer_read+0x9c/0x3f4 [g_printer]) from [<c01387f0>] (vfs_read+0xb4/0x144)
[<c01387f0>] (vfs_read+0xb4/0x144) from [<c01388d0>] (sys_read+0x50/0x124)
[<c01388d0>] (sys_read+0x50/0x124) from [<c000e900>] (ret_fast_syscall+0x0/0x3c)

The root cause is that we use the same lock two time in a path, so to avoid
the deadlock, we need to unlock in setup_rx_reqs(), and only unlock.
Signed-off-by: wenlin.kang <wenlin.kang@windriver.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

Fixes the following compilation warning:
drivers/usb/gadget/s3c-hsudc.c: In function ‘s3c_hsudc_probe’:
drivers/usb/gadget/s3c-hsudc.c:1347:1: warning: label ‘err_add_device’
defined but not used [-Wunused-label]
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>

Pass value instead of address as expected by 'usb_ep_set_maxpacket_limit'.
Fixes the following compilation error introduced by commit e117e742
("usb: gadget: add "maxpacket_limit" field to struct usb_ep"):

drivers/usb/gadget/s3c2410_udc.c: In function ‘s3c2410_udc_reinit’:
drivers/usb/gadget/s3c2410_udc.c:1632:3: error:
cannot take address of bit-field ‘maxpacket’
   usb_ep_set_maxpacket_limit(&ep->ep, &ep->ep.maxpacket);
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Reviewed-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

Set the return variable to an error code as done elsewhere in the function.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
(
if@p1 (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret@p1 = 0
)
... when != ret = e1
    when != &ret
*if(...)
{
  ... when != ret = e2
      when forall
 return ret;
}

// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Felipe Balbi <balbi@ti.com>

Use %pad for dma_addr_t to avoid the following build warnings
in printks.

drivers/usb/gadget/s3c-hsotg.c: In function 's3c_hsotg_start_req'
drivers/usb/gadget/s3c-hsotg.c:722:3: warning: format '%x' expects argument of type 'unsigned int' but argument 6 has type
'dma_addr_t' [-Wformat]
drivers/usb/gadget/s3c-hsotg.c:792:3: warning: format '%x' expects argument of type 'unsigned int' but argument 5 has type
'dma_addr_t' [-Wformat]
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

The readsl and writesl I/O accessors are only defined on some
architectures. The driver currently depends on CONFIG_ARM because
the build breaks on x86, in particular. Switch to use of ioread32_rep
and iowrite32_rep to fix build on all architectures and remove the
CONFIG_ARM dependency.

Also update printk formatting to handle a long long dma_addr_t to avoid
warnings on !32-bit architectures.
Signed-off-by: Matt Porter <mporter@linaro.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>

In case of ISOCH transfers the hrtimer workaround for the hardware issue
is not very reliable. Instead of checking musb_is_tx_fifo_empty() in hrtimer
routine, schedule a completion work and check the same in completion work.
Signed-off-by: George Cherian <george.cherian@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

Enable CPPI to handle high bandwidth transfers, especially to support
webcam captures. Use a single bd to get the whole of the data in case of
high bandwidth transfers.
Signed-off-by: George Cherian <george.cherian@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

Enable the isochrounous IN handling for AM335x HOST.
Reprogram CPPI to receive consecutive ISOCH frames in the same URB.
Signed-off-by: George Cherian <george.cherian@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

include/phy/phy.h has stub code in there for when building without the
phy-core enabled. This is useful for generic drivers such as ahci-platform,
ehci-platoform and ohci-platform which have support for driving an optional
phy passed to them through the devicetree.

Since on some boards this phy functionality is not needed, being able to
disable the phy subsystem without needing a lot of #ifdef magic in the
driver using it is quite useful.

However this breaks when the module using the phy subsystem is build-in and
the phy-core is not, which leads to the build failing with missing symbol
errors in the linking stage of the zImage.

Which leads to gems such as this being added to the Kconfig for achi_platform:

	depends on GENERIC_PHY || !GENERIC_PHY

Rather then duplicating this code in a lot of places using the phy-core,
I believe it is better to simply not allow the phy-core to be built as a
module. The phy core is quite small and has no external dependencies, so
always building it in when enabling it should not be an issue.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The "Webmail Notifier" is a USB controlled LED that appears as a HID
device. When trying to change the LED via hidraw it returns malformed
reports. As "usbled" supports it, we blacklist it in usbhid.
Signed-off-by: Christian Vogel <vogelchr@vogel.cx>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

In a couple of places, we were checking qtd->urb for NULL after
we had already dereferenced it. Fix this by moving the check to
before the dereference.
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This brings the xhci-platform bindings in sync with what we've done for
the ohci- and ehci-platform drivers. As discussed there using platform as a
postfix is a bit weird as the platform bus is a Linux specific thing and
the bindings are supposed to be OS agnostic.

Note that the old xhci-platform compatible string is kept around for, well,
compatibility reasons.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This brings the uhci-platform bindings in sync with what we've done for
the ohci- and ehci-platform drivers. As discussed there using platform as a
prefix is a bit weird as the platform bus is a Linux specific thing and
the bindings are supposed to be OS agnostic.

Note that the old platform-uhci compatible string is kept around for, well,
compatibility reasons.

While at it rename the bindings txt file to match the name of all the
other ?hci-platform bindings docs.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add support for the "Webmail Notifier" (USB powered LED for signaling
new emails) made by Riso Kagaku Corp. which displays 7 distinct colors.

USB Protocol initially reverse engineered by
	https://code.google.com/p/usbmailnotifier/.
Signed-off-by: Christian Vogel <vogelchr@vogel.cx>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The Kconfig entries for USB_U132_HCD and USB_FTDI_ELAN default to
(uppercase) "M". But in Kconfig (lowercase) "m" is a magic symbol. "M"
is an ordinary symbol. As "M" is never set these Kconfig symbols will
also not be set by default.

Since I'm not aware of a reason why these driver should be set by
default, let's just drop these lines (that basically do nothing).
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The symbol is an orphan, get rid of it.
Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The ohci-platform driver checks for misconfigurations in cases where
the Device Tree data specifies big-endian registers or descriptors but
the corresponding driver config settings have not been enabled.  As
Jonas Gorski suggested, we may as well apply the same check to general
platform data too.

This requires moving the code that sets the big-endian quirk flags
from the ohci_platform_reset() routine into ohci_platform_probe(), and
moving the checks out of the DT-specific "if" statement clause.

The patch also changes the text of the error messages in an attempt to
make the nature of the error more clear.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Jonas Gorski <jogo@openwrt.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The ehci-platform driver checks for misconfigurations in cases where
the Device Tree data specifies big-endian registers or descriptors but
the corresponding driver config settings have not been enabled.  As
Jonas Gorski suggested, we may as well apply the same check to general
platform data too.

This requires moving the code that sets the big-endian quirk flags
from the ehci_platform_reset() routine into ehci_platform_probe(), and
moving the checks out of the DT-specific "if" statement clause.

The patch also changes the text of the error messages in an attempt to
make the nature of the error more clear.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Jonas Gorski <jogo@openwrt.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The initial versions of the devicetree enablement patches for ehci-platform
used "ehci-platform" as compatible string. However this was disliked by various
reviewers because the platform bus is a Linux invention and devicetree is
supposed to be OS agnostic. After much discussion I gave up, added a:
"depends on !PPC_OF" to Kconfig to avoid a known conflict with PPC-OF platforms
and went with the generic usb-ehci as requested.

In retro-spect I should have chosen something different, the dts files for many
existing boards already claim to be compatible with "usb-ehci", ie they have:

	compatible = "ti,ehci-omap", "usb-ehci";

In theory this should not be a problem since the "ti,ehci-omap" entry takes
presedence, but in practice using a conflicting compatible string is an issue,
because it makes which driver gets used depend on driver registration order.

This patch changes the compatible string claimed by ehci-platform to
"generic-ehci", avoiding the driver registration / module loading ordering
problems, and removes the "depends on !PPC_OF" workaround.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The initial versions of the devicetree enablement patches for ohci-platform
used "ohci-platform" as compatible string. However this was disliked by various
reviewers because the platform bus is a Linux invention and devicetree is
supposed to be OS agnostic. After much discussion I gave up and went with
the generic usb-ohci as requested.

In retro-spect I should have chosen something different, the dts files for many
existing boards already claim to be compatible with "usb-ohci", ie they have:

	compatible = "ti,ohci-omap3", "usb-ohci";

In theory this should not be a problem since the "ti,ohci-omap3" entry takes
presedence, but in practice using a conflicting compatible string is an issue,
because it makes which driver gets used depend on driver registration order.

This patch changes the compatible string claimed by ohci-platform to
"generic-ohci", avoiding the driver registration / module loading ordering
problems.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Kevin Hilman <khilman@linaro.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Allow the scheduler to select the best CPU to handle hub initalization
and LED blinking work. This extends idle residency times on idle CPUs
and conserves power.

This functionality is enabled when CONFIG_WQ_POWER_EFFICIENT is selected.

[zoran.markovic@linaro.org: Rebased to latest kernel. Added commit message.
Changed reference from system to power efficient workqueue for LEDs in
check_highspeed() and hub_port_connect_change().]
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Xenia Ragiadakou <burzalodowa@gmail.com>
Cc: Julius Werner <jwerner@chromium.org>
Cc: Krzysztof Mazur <krzysiek@podlesie.net>
Cc: Matthias Beyer <mail@beyermatthias.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Cc: Thomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: Shaibal Dutta <shaibal.dutta@broadcom.com>
Signed-off-by: Zoran Markovic <zoran.markovic@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Free "motog" on error.  This is more to appease the static checkers than
a real worry.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

According to the spec for the DWC2 controller, when the PRTINT interrupt fires,
the application must clear the appropriate status bit in the Host Port Control
and Status register to clear this bit.

When disconnecting an A-cable when the dwc2 host driver, the PRTINT fires, but
only the GINTSTS_PRTINT status is cleared, no action is done with the HPRT0
register. The HPRT0_ENACHG bit in the HPRT0 must also be poked to correctly
clear the GINTSTS_PRTINT interrupt.

I am seeing this behavoir on v2.93 of the DWC2 IP. When I disconnect an OTG
A-cable adapter, the PRTINT interrupt fires when the DWC2 is in device mode
and is never cleared.

This patch adds the function to read the HPRT0 register when the PRTINT fires
and the dwc2 IP has already transitioned to device mode. This function is only
clearing the HPRT0_ENACHG bit for now, but can be modified to handle more.
Signed-off-by: Dinh Nguyen <dinguyen@altera.com>
[ paulz: modified patch to preserve HPRT0_ENA bit ]
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This uses the already documented devicetree booleans for this, see:
Documentation/devicetree/bindings/usb/usb-ehci.txt
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Note this commit uses the same devicetree booleans for this as the ones
already existing in the usb-ehci bindings, see:
Documentation/devicetree/bindings/usb/usb-ehci.txt
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Currently ehci-platform is only used in combination with devicetree when used
with some Via socs. By extending it to (optionally) get clks and a phy from
devicetree, and enabling / disabling those on power_on / off, it can be used
more generically. Specifically after this commit it can be used for the
ehci controller on Allwinner sunxi SoCs.

Since ehci-platform is intended to handle any generic enough non pci ehci
device, add a "usb-ehci" compatibility string.

There already is a usb-ehci device-tree bindings document, update this
with clks and phy bindings info.

Although actually quite generic so far the via,vt8500 compatibilty string
had its own bindings document. Somehow we even ended up with 2 of them. Since
these provide no extra information over the generic usb-ehci documentation,
this patch removes them.

The ehci-ppc-of.c driver also claims the usb-ehci compatibility string,
even though it mostly is ibm,usb-ehci-440epx specific. ehci-platform.c is
not needed on ppc platforms, so add a !PPC_OF dependency to it to avoid
2 drivers claiming the same compatibility string getting build on ppc.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>