drm: kerneldoc polish for drm_crtc_helper.c

Most of this is newly added kerneldoc for the hotplug and output
polling code. But I've also thrown in a bit lesser polish, most of it
is tuning down the shouting RETURN: headers.

Overview documentation for the output probing and mode setting support
code will be added in later patches.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drm: kerneldoc polish for drm_crtc.c

- Standardized on "Returns:" Block.
- Sprinkle missing kerneldoc over all exported functions and all
  ioctls.
- Add a stern warning that driver's really shouldn't use
  drm_mode_group_init_legacy_group.
- Usual attempt at more consistency.
- Add warnings that drm_mode_object_get/put don't do refcounting,
  despite what the names might lead to believe.
- Try to clarify the framebuffer setup/cleanup functions wrt driver
  private framebuffers - I've fallen recently over this when reviewing
  i915 fbdev patches.
- Align function parameters where the kerneldoc has been updated.
- Most of the drm_get_*_name functions aren't thread safe. Add stern
  warnings where this is the case.

Since a lot of the functions in drm_crtc.c are boilerplate to handle
properties and create default sets of them it might be useful to
extract all that code into a new file drm_property.c. Especially since
properties will be used a lot more in the future.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drm/i915: Remove erronous WARN in the vlv pipe crc code

It's been in there since forever, and no one cared. Doesn't put a too
good light onto our bug handling and QA efforts really ...

References: https://bugs.freedesktop.org/attachment.cgi?id=90970
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drm/i915: Consolidate forcewake resetting to a single function

We have two paths that try to reset the forcewake registers back to
known good values, with slightly different semantics and levels of
paranoia. Combine the two by passing a parameter to either restore the
forcewake status or to clear our bookkeeping, and raise the paranoia
level to max.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
i2c: Add message transfer tracepoints for I2C

Add tracepoints into the I2C message transfer function to retrieve the message
sent or received.  The following config options must be turned on to make use
of the facility:

	CONFIG_FTRACE
	CONFIG_ENABLE_DEFAULT_TRACERS

The I2C tracepoint can be enabled thusly:

	echo 1 >/sys/kernel/debug/tracing/events/i2c/enable

and will dump messages that can be viewed in /sys/kernel/debug/tracing/trace
that look like:

	... i2c_write: i2c-5 #0 a=044 f=0000 l=2 [02-14]
	... i2c_read: i2c-5 #1 a=044 f=0001 l=4
	... i2c_reply: i2c-5 #1 a=044 f=0001 l=4 [33-00-00-00]
	... i2c_result: i2c-5 n=2 ret=2

formatted as:

	i2c-<adapter-nr>
	#<message-array-index>
	a=<addr>
	f=<flags>
	l=<datalen>
	n=<message-array-size>
	ret=<result>
	[<data>]

The operation is done between the i2c_write/i2c_read lines and the i2c_reply
and i2c_result lines so that if the hardware hangs, the trace buffer can be
consulted to determine the problematic operation.

The adapters to be traced can be selected by something like:

	echo adapter_nr==1 >/sys/kernel/debug/tracing/events/i2c/filter

These changes are based on code from Steven Rostedt.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
[wsa: adapted path for 'enable' in the commit msg]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
i2c: Add message transfer tracepoints for SMBUS [ver #2]

The SMBUS tracepoints can be enabled thusly:

	echo 1 >/sys/kernel/debug/tracing/events/i2c/enable

and will dump messages that can be viewed in /sys/kernel/debug/tracing/trace
that look like:

         ... smbus_read: i2c-0 a=051 f=0000 c=fa BYTE_DATA
         ... smbus_reply: i2c-0 a=051 f=0000 c=fa BYTE_DATA l=1 [39]
         ... smbus_result: i2c-0 a=051 f=0000 c=fa BYTE_DATA rd res=0

formatted as:

	i2c-<adapter-nr>
	a=<addr>
	f=<flags>
	c=<command>
	<protocol-name>
	<rd|wr>
	res=<result>
	l=<data-len>
	[<data-block>]

The adapters to be traced can be selected by something like:

	echo adapter_nr==1 >/sys/kernel/debug/tracing/events/i2c/filter

Note that this shares the same filter and enablement as i2c.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
i2c: gpio: OF gpio code does not handle defered probe case

When using device-tree and the i2c-gpio driver is called before the
GPIO node has been probed then it needs to correctly defer the probe
instead of returning a permanent error that the gpio numbers are not
valid.

This fixes the following error:
	/i2c@2: invalid GPIO pins, sda=-517/scl=-517

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
i2c: exynos5: add CONFIG_PM_SLEEP to suspend/resume functions

Add CONFIG_PM_SLEEP to suspend/resume functions to fix the following
build warning when CONFIG_PM_SLEEP is not selected. This is because
sleep PM callbacks defined by SIMPLE_DEV_PM_OPS are only used when
the CONFIG_PM_SLEEP is enabled.

  warning: 'exynos5_i2c_suspend_noirq' defined but not used [-Wunused-function]
  warning: 'exynos5_i2c_resume_noirq' defined but not used [-Wunused-function]

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
i2c: exynos5: remove unnecessary cast of void pointer

Remove unnecessary cast of void pointer, because 'algo_data' of
'struct i2c_adapter' is a void pointer. Casting the void pointer
is redundant. The conversion from void pointer to any other
pointer type is guaranteed by the C programming language.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Reviewed-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
leds: clevo-mail: Make probe function __init

One of the benefits of platform_driver_probe() is that you can make
the probe function __init.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Bryan Wu <cooloney@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
drm/imx: remove drm_mode_connector_detach_encoder harder

Since the last time I've looked more of this stuff sprouted up. Stomp
it down again.

Repeating the original justification for ripping this all out: There's
absolutely no need to deteach connectors before cleaning them up at
driver unload time. And since drm doesn't support hotplugging kms
objects at all it's positively dangerous to attempt this at runtime.
Luckily imx only detachs at driver cleanup time and hence we can
savely remove this.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drm/udl: fix error-path when damage-req fails

We need to call dma_buf_end_cpu_access() in case a damage-request.
Unlikely, but might happen during device unplug.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
drm/udl: fix Bpp calculation in dumb_create()

Probably a typo.. we obviously need "(bpp + 7) / 8" instead of
"(bpp + 1) / 8". Unlikely to be hit in any sane code, but lets be safe.
Use DIV_ROUND_UP() to avoid the problem entirely and make the core more
readable.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
drm/gem: fix indentation

Remove double-whitespace and wrong indentation.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
drm/gem: free vma-node during object-cleanup

All drivers currently need to clean up the vma-node manually. There is no
fancy logic involved so lets just clean it up unconditionally. The
vma-manager correctly catches multiple calls so we are fine.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
drm/crtc: add sanity checks to create_dumb()

Lets make sure some basic expressions are always true:
  bpp != NULL
  width != NULL
  height != NULL
  stride = bpp * width < 2^32
  size = stride * height < 2^32
  PAGE_ALIGN(size) < 2^32

At least the udl driver doesn't check for multiplication-overflows, so
lets just make sure it will never happen. These checks allow drivers to do
any 32bit math without having to test for mult-overflows themselves.

The two divisions might hurt performance a bit, but dumb_create() is only
used for scanout-buffers, so that should be fine. We could use 64bit math
to avoid the divisions, but that may be slow on 32bit machines.. Or maybe
there should just be a "safe_mult32()" helper, which currently doesn't
exist (I think?).

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
drm/gem: dont init "ret" in drm_gem_mmap()

There is no need to initialize this variable, so drop it. Otherwise, the
compiler won't warn if we use it unintialized.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
drm: add pseudo filesystem for shared inodes

Our current DRM design uses a single address_space for all users of the
same DRM device. However, there is no way to create an anonymous
address_space without an underlying inode. Therefore, we wait for the
first ->open() callback on a registered char-dev and take-over the inode
of the char-dev. This worked well so far, but has several drawbacks:
 - We screw with FS internals and rely on some non-obvious invariants like
   inode->i_mapping being the same as inode->i_data for char-devs.
 - We don't have any address_space prior to the first ->open() from
   user-space. This leads to ugly fallback code and we cannot allocate
   global objects early.

As pointed out by Al-Viro, fs/anon_inode.c is *not* supposed to be used by
drivers for anonymous inode-allocation. Therefore, this patch follows the
proposed alternative solution and adds a pseudo filesystem mount-point to
DRM. We can then allocate private inodes including a private address_space
for each DRM device at initialization time.

Note that we could use:
  sysfs_get_inode(sysfs_mnt->mnt_sb, drm_device->dev->kobj.sd);
to get access to the underlying sysfs-inode of a "struct device" object.
However, most of this information is currently hidden and it's not clear
whether this address_space is suitable for driver access. Thus, unless
linux allows anonymous address_space objects or driver-core provides a
public inode per device, we're left with our own private internal mount
point.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
drm: use anon-inode instead of relying on cdevs

DRM drivers share a common address_space across all character-devices of a
single DRM device. This allows simple buffer eviction and mapping-control.
However, DRM core currently waits for the first ->open() on any char-dev
to mark the underlying inode as backing inode of the device. This delayed
initialization causes ugly conditions all over the place:
  if (dev->dev_mapping)
    do_sth();

To avoid delayed initialization and to stop reusing the inode of the
char-dev, we allocate an anonymous inode for each DRM device and reset
filp->f_mapping to it on ->open().

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
drm: init TTM dev_mapping in ttm_bo_device_init()

With dev->anon_inode we have a global address_space ready for operation
right from the beginning. Therefore, there is no need to do a delayed
setup with TTM. Instead, set dev_mapping during initialization in
ttm_bo_device_init() and remove any "if (dev_mapping)" conditions.

Cc: Dave Airlie <airlied@redhat.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Cc: Alex Deucher <alexdeucher@gmail.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>