mode_fixup function for encoder drivers became optional with patch
http://patchwork.freedesktop.org/patch/msgid/1455106522-32307-1-git-send-email-palminha@synopsys.com

This patch set nukes all the dummy mode_fixup implementations.

(made on top of Daniel topic/drm-misc branch)
Signed-off-by: NCarlos Palminha <palminha@synopsys.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1b99680b8cf81977597dec5daedff9b684d3ed19.1455540137.git.palminha@synopsys.com

mode_fixup function for encoder drivers became optional with patch
http://patchwork.freedesktop.org/patch/msgid/1455106522-32307-1-git-send-email-palminha@synopsys.com

This patch set nukes all the dummy mode_fixup implementations.

(made on top of Daniel topic/drm-misc branch)
Signed-off-by: NCarlos Palminha <palminha@synopsys.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/a53767402bd4a69c3d2a546b7f4d4d122134b545.1455540137.git.palminha@synopsys.com

mode_fixup function for encoder drivers became optional with patch
http://patchwork.freedesktop.org/patch/msgid/1455106522-32307-1-git-send-email-palminha@synopsys.com

This patch set nukes all the dummy mode_fixup implementations.

(made on top of Daniel topic/drm-misc branch)
Signed-off-by: NCarlos Palminha <palminha@synopsys.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/d8b87edea28c8211e1711348143e4c355764a8c4.1455540137.git.palminha@synopsys.com

mode_fixup function for encoder drivers became optional with patch
http://patchwork.freedesktop.org/patch/msgid/1455106522-32307-1-git-send-email-palminha@synopsys.com

This patch set nukes all the dummy mode_fixup implementations.

(made on top of Daniel topic/drm-misc branch)
Signed-off-by: NCarlos Palminha <palminha@synopsys.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/12e1e900724c890166b88b0f4d67baba387482af.1455540137.git.palminha@synopsys.com

mode_fixup function for encoder drivers became optional with patch
http://patchwork.freedesktop.org/patch/msgid/1455106522-32307-1-git-send-email-palminha@synopsys.com

This patch set nukes all the dummy mode_fixup implementations.

(made on top of Daniel topic/drm-misc branch)
Signed-off-by: NCarlos Palminha <palminha@synopsys.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/8c4710ee930d2ab3a505b8d3cd724f4f4c79b3df.1455540137.git.palminha@synopsys.com

mode_fixup function for encoder drivers became optional with patch
http://patchwork.freedesktop.org/patch/msgid/1455106522-32307-1-git-send-email-palminha@synopsys.com

This patch set nukes all the dummy mode_fixup implementations.

(made on top of Daniel topic/drm-misc branch)
Signed-off-by: NCarlos Palminha <palminha@synopsys.com>
[danvet: Squash in 2nd exynos patch.]
Link: http://patchwork.freedesktop.org/patch/msgid/3768b670931572de51fca1102efa18d20dd770ee.1455540137.git.palminha@synopsys.com
Link: http://patchwork.freedesktop.org/patch/msgid/4906a9925eebbe55489b1005c449b426a61c09bd.1455540137.git.palminha@synopsys.comSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

mode_fixup function for encoder drivers became optional with patch
http://patchwork.freedesktop.org/patch/msgid/1455106522-32307-1-git-send-email-palminha@synopsys.com

This patch set nukes all the dummy mode_fixup implementations.

(made on top of Daniel topic/drm-misc branch)
Signed-off-by: NCarlos Palminha <palminha@synopsys.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/a7ebfb6c6c333056d0a77d2684c539107ee63589.1455540137.git.palminha@synopsys.com

mode_fixup function for encoder drivers became optional with patch
http://patchwork.freedesktop.org/patch/msgid/1455106522-32307-1-git-send-email-palminha@synopsys.com

This patch set nukes all the dummy mode_fixup implementations.

(made on top of Daniel topic/drm-misc branch)
Signed-off-by: NCarlos Palminha <palminha@synopsys.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/85230bc1356eb52257aaa1e1965adae2f00db5cd.1455540137.git.palminha@synopsys.com

add_all_connectors doesn't checks whether reallocation is needed, but add_one does.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455540316-17066-2-git-send-email-maarten.lankhorst@linux.intel.com

The fb helper iterates over connectors, using fb_helper->num_connectors
makes it more clear what size the allocations are.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455540316-17066-1-git-send-email-maarten.lankhorst@linux.intel.com

So far, the i915 driver and some other drivers set it to the drm_device,
which doesn't allow one to know which DP a given aux channel is related
to. Changing this to be the drm_connector provides proper nesting, still
allowing one to get the drm_device from it. Some drivers already set it
to the drm_connector.

This also removes the need to add a sysfs link for the i2c device under
the connector, as it will already be there.

v9:
 - As a side effect, drm_dp_aux_unregister() must be called before
 intel_connector_unregister(), as both the aux.dev and the i2c adapter
 dev are children of the drm_connector device now. Calling
 drm_dp_aux_unregister() before prevents them from being destroyed
 twice.

v10:
 - move aux_fini() to connector_unregister(), instead of moving
 drm_dp_aux_unregister() outside of connector_register().
Signed-off-by: NRafael Antognolli <rafael.antognolli@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1453417821-2811-4-git-send-email-rafael.antognolli@intel.com

The userspace might need some sort of cache coherency management e.g. when CPU
and GPU domains are being accessed through dma-buf at the same time. To
circumvent this problem there are begin/end coherency markers, that forward
directly to existing dma-buf device drivers vfunc hooks. Userspace can make use
of those markers through the DMA_BUF_IOCTL_SYNC ioctl. The sequence would be
used like following:
     - mmap dma-buf fd
     - for each drawing/upload cycle in CPU 1. SYNC_START ioctl, 2. read/write
       to mmap area 3. SYNC_END ioctl. This can be repeated as often as you
       want (with the new data being consumed by the GPU or say scanout device)
     - munmap once you don't need the buffer any more

v2 (Tiago): Fix header file type names (u64 -> __u64)
v3 (Tiago): Add documentation. Use enum dma_buf_sync_flags to the begin/end
dma-buf functions. Check for overflows in start/length.
v4 (Tiago): use 2d regions for sync.
v5 (Tiago): forget about 2d regions (v4); use _IOW in DMA_BUF_IOCTL_SYNC and
remove range information from struct dma_buf_sync.
v6 (Tiago): use __u64 structured padded flags instead enum. Adjust
documentation about the recommendation on using sync ioctls.
v7 (Tiago): Alex' nit on flags definition and being even more wording in the
doc about sync usage.
v9 (Tiago): remove useless is_dma_buf_file check. Fix sync.flags conditionals
and its mask order check. Add <linux/types.h> include in dma-buf.h.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Reviewed-by: NStéphane Marchesin <marcheu@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NTiago Vignatti <tiago.vignatti@intel.com>
Reviewed-by: NDavid Herrmann <dh.herrmann@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455228291-29640-1-git-send-email-tiago.vignatti@intel.com

This module is heavily based on i2c-dev. Once loaded, it provides one
dev node per DP AUX channel, named drm_dp_auxN, where N is an integer.

It's possible to know which connector owns this aux channel by looking
at the respective sysfs /sys/class/drm_aux_dev/drm_dp_auxN/connector, if
the connector device pointer was correctly set in the aux helper struct.

Two main operations are provided on the registers read and write. The
address of the register to be read or written is given using lseek. The
seek position is updated upon read or write.

v2:
 - lseek is used to select the register to read/write
 - read/write are used instead of ioctl
 - no blocking_notifier is used, just a direct callback

v3:
 - use drm_dp_aux_dev prefix for public functions
 - chardev is named drm_dp_auxN
 - read/write don't allocate a buffer anymore, and transfer up to 16 bytes a
   time
 - remove notifier list from the implementation
 - option on menuconfig is now a boolean
 - add inline stub functions to avoid breakage when this option is disabled

v4:
 - fix build system changes - actually disable this module when not selected.

v5:
 - Use kref to avoid device closing while still in use
 - Don't use list, use an idr for storing aux_dev
 - Remove "connector" attribute
 - set aux.dev to the connector drm_connector device, instead of
   drm_device

v6:
 - Use atomic_t for usage count
 - Use a mutex instead of spinlock for idr lock
 - Destroy chardev immediately on unregister
 - other minor suggestions from Ville

v7:
 - style fixes
 - error handling fixes

v8:
 - more error handling fixes

v9:
 - remove module_init and module_exit, and add drm_dp_aux_dev_init/exit
 to drm_kms_helper_init/exit.
Signed-off-by: NRafael Antognolli <rafael.antognolli@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1453417821-2811-3-git-send-email-rafael.antognolli@intel.com

The module_init and module_exit functions will start here, and call the
subsequent init's and exit's.

v10:
 - Keep __init on drm_fb_helper init function.
 - Move MODULE_* macros to the common file.
Signed-off-by: NRafael Antognolli <rafael.antognolli@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1453417821-2811-2-git-send-email-rafael.antognolli@intel.com

After the drm_device_is_unplugged() was removed, the 'dev' variable is now
unused, and we get a warning for that:

drivers/gpu/drm/msm/msm_fbdev.c: In function 'msm_fbdev_mmap':
drivers/gpu/drm/msm/msm_fbdev.c:65:21: error: unused variable 'dev' [-Werror=unused-variable]

This removes the variable as well.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Fixes: e9f8250f ("drm/msm: remove the drm_device_is_unplugged check")
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455181810-3910161-1-git-send-email-arnd@arndb.de

Other bridge drivers don't implement this optional function.
Removed dummy code from dw-hdmi brigde driver.
Signed-off-by: NCarlos Palminha <palminha@synopsys.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455120639-29934-1-git-send-email-palminha@synopsys.com

Removed dummy mode_fixup.
Signed-off-by: NCarlos Palminha <palminha@synopsys.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455118167-12178-3-git-send-email-palminha@synopsys.com

Removed dummy mode_fixup.
Signed-off-by: NCarlos Palminha <palminha@synopsys.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455118167-12178-2-git-send-email-palminha@synopsys.com

The DRM drivers i915, nouveau and radeon may be compiled with
CONFIG_ACPI not set, in which case acpi_dev_present() is undefined.

Add a no-op stub for apple_gmux_present() which is used if
CONFIG_APPLE_GMUX is not enabled to avoid build breakage.
(CONFIG_APPLE_GMUX depends on CONFIG_ACPI.)
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20160210131741.GA15492@wunner.de

Avoids null crash when encoders don't implement mode_fixup.
Signed-off-by: NCarlos Palminha <palminha@synopsys.com>
[danvet: Also update kerneldoc.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455106522-32307-1-git-send-email-palminha@synopsys.com

Avoid i2c slave encoder drivers to copy/paste code to implement functions that will
only return true.
Signed-off-by: NCarlos Palminha <palminha@synopsys.com>
[danvet: whitespace requested by Jani.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455106118-32145-1-git-send-email-palminha@synopsys.com

The current code fails to call i2c_del_adapter on
dev_prev->gmbus[0].adapter, and if the for loop above failed already
at i==0, all hell breaks loose when we do the loop body for
i = -1,-2,...
Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Link: http://patchwork.freedesktop.org/patch/msgid/1455048677-19882-2-git-send-email-linux@rasmusvillemoes.dkReviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Add a few helpers to get the dimensions of the chroma plane(s).

v2: Add kernel-doc (Daniel)
v3: Fix kerneldoc "Returns:" style (Daniel)
    Uninline the functions and check for num_planes (Daniel)
v4: Add the required EXPORT_SYMBOL()s

Cc: dri-devel@lists.freedesktop.org
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455031784-10941-1-git-send-email-ville.syrjala@linux.intel.com

This flag is only used for drm/udl.
Signed-off-by: NHaixia Shi <hshi@chromium.org>
Reviewed-by: NStéphane Marchesin <marcheu@chromium.org>
Reviewed-by: NDavid Herrmann <dh.herrmann@gmail.com>
Acked-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1454709464-2536-1-git-send-email-hshi@chromium.org

The warning message in drm_mode_parse_command_line_for_connector miss
the [drm] at beginning.
This patch add it and take the opportunity to convert
printk(KERN_WARNING to pr_warn()
Signed-off-by: NLABBE Corentin <clabbe.montjoie@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1454594633-15100-1-git-send-email-clabbe.montjoie@gmail.com

Since drm_property_create_range can be failed in memory pressure,
it needs to be checked and return -ENOMEM.
Signed-off-by: NInsu Yun <wuninsu@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1454025276-13465-1-git-send-email-wuninsu@gmail.com

gmux is a microcontroller built into dual GPU MacBook Pros.
On pre-retina MBPs, if we're the inactive GPU, we need apple-gmux
to temporarily switch DDC so that we can probe the panel's EDID.

The checks for CONFIG_VGA_ARB and CONFIG_VGA_SWITCHEROO are necessary
because if either of them is disabled but gmux is present, the driver
would never load, even if we're the active GPU. (vga_default_device()
would evaluate to NULL and vga_switcheroo_handler_flags() would
evaluate to 0.)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=61115Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/552da6d85a82092146af7b0693595fa2a9ea376b.1452525860.git.lukas@wunner.de

gmux is a microcontroller built into dual GPU MacBook Pros.
On pre-retina MBPs, if we're the inactive GPU, we need apple-gmux
to temporarily switch DDC so that we can probe the panel's EDID.

The checks for CONFIG_VGA_ARB and CONFIG_VGA_SWITCHEROO are necessary
because if either of them is disabled but gmux is present, the driver
would never load, even if we're the active GPU. (vga_default_device()
would evaluate to NULL and vga_switcheroo_handler_flags() would
evaluate to 0.)

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=88861
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=61115Tested-by: NLukas Wunner <lukas@wunner.de>
    [MBP  9,1 2012  intel IVB + nvidia GK107  pre-retina  15"]
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/d9542ca5041178165d3ff286c90cc99634f7d2ce.1452525860.git.lukas@wunner.de

gmux is a microcontroller built into dual GPU MacBook Pros.
On pre-retina MBPs, if we're the inactive GPU, we need apple-gmux
to temporarily switch DDC so that we can probe the panel's EDID.

The checks for CONFIG_VGA_ARB and CONFIG_VGA_SWITCHEROO are necessary
because if either of them is disabled but gmux is present, the driver
would never load, even if we're the active GPU. (vga_default_device()
would evaluate to NULL and vga_switcheroo_handler_flags() would
evaluate to 0.)

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=88861
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=61115Tested-by: NLukas Wunner <lukas@wunner.de>
    [MBP  9,1 2012  intel IVB + nvidia GK107  pre-retina  15"]
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/f56ee6a0600a3e1bb5bed4d0db4ed9ade7445c47.1452525860.git.lukas@wunner.de

Centralize gmux' ACPI HID in a header file and add apple_gmux_present().
This can be used by other drivers to activate quirks specific to dual
GPU MacBook Pros & Mac Pros. The alternative would be to hardcode DMI
or PCI IDs and amend them whenever Apple introduces a new machine.
Tested-by: NLukas Wunner <lukas@wunner.de>
    [MBP  9,1 2012  intel IVB + nvidia GK107  pre-retina  15"]
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Reviewed-by: NDarren Hart <dvhart@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/89c23769058a340e5e11d4a7102f3793d3b0c94c.1452525860.git.lukas@wunner.de

The pre-retina MacBook Pro uses an LVDS panel and a gmux controller
to switch the panel between its two GPUs. The panel mode in VBIOS
is notoriously bogus on these machines.

Use drm_get_edid_switcheroo() in lieu of drm_get_edid() on LVDS
if the vga_switcheroo handler is capable of temporarily switching
the panel's DDC lines to the discrete GPU. This allows us to retrieve
the EDID if the panel is currently muxed to the integrated GPU.

This only enables EDID probing on the pre-retina MBP (2008 - 2013).
The retina MBP (2012 - present) uses eDP and gmux is not capable of
switching AUX separately from the main link on these models.
This will be addressed in later patches.

List of pre-retina MBPs with dual GPUs, one of them AMD:
    [MBP  8,2 2011  intel SNB + amd turks     pre-retina  15"]
    [MBP  8,3 2011  intel SNB + amd turks     pre-retina  17"]

v3: Commit newly added due to introduction of drm_get_edid_switcheroo()
    wrapper which drivers need to opt-in to.

v5: Rebase on "vga_switcheroo: Add handler flags infrastructure",
    i.e. call drm_get_edid_switcheroo() only if the handler
    indicates that DDC is switchable.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=61115Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/dae71655e8c484fbef492d3389c157975f9622c9.1452525860.git.lukas@wunner.de

The pre-retina MacBook Pro uses an LVDS panel and a gmux controller
to switch the panel between its two GPUs. The panel mode in VBIOS
is notoriously bogus on these machines.

Use drm_get_edid_switcheroo() in lieu of drm_get_edid() on LVDS
if the vga_switcheroo handler is capable of temporarily switching
the panel's DDC lines to the discrete GPU. This allows us to retrieve
the EDID if the panel is currently muxed to the integrated GPU.
Likewise, ask vga_switcheroo to switch DDC before probing LVDS
connectors.

This only enables EDID probing on the pre-retina MBP (2008 - 2013).
The retina MBP (2012 - present) uses eDP and gmux is not capable of
switching AUX separately from the main link on these models.
This will be addressed in later patches.

List of pre-retina MBPs with dual GPUs, either or both Nvidia:
    [MBP  5,1 2008  nvidia MCP79 + G96        pre-retina  15"]
    [MBP  5,2 2009  nvidia MCP79 + G96        pre-retina  17"]
    [MBP  5,3 2009  nvidia MCP79 + G96        pre-retina  15"]
    [MBP  6,2 2010  intel ILK + nvidia GT216  pre-retina  15"]
    [MBP  6,1 2010  intel ILK + nvidia GT216  pre-retina  17"]
    [MBP  9,1 2012  intel IVB + nvidia GK107  pre-retina  15"]

v3: Commit newly added due to introduction of drm_get_edid_switcheroo()
    wrapper which drivers need to opt-in to.

v5: Rebase on "vga_switcheroo: Add handler flags infrastructure",
    i.e. call drm_get_edid_switcheroo() only if the handler
    indicates that DDC is switchable.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=88861
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=61115Tested-by: NLukas Wunner <lukas@wunner.de>
    [MBP  9,1 2012  intel IVB + nvidia GK107  pre-retina  15"]
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/e9466eb3d66b5b30f1e93c3b3da79d8b9ad0830f.1452525860.git.lukas@wunner.de

The pre-retina MacBook Pro uses an LVDS panel and a gmux controller
to switch the panel between its two GPUs. The panel mode in VBIOS
is notoriously bogus on these machines and some models have no
VBIOS at all.

Use drm_get_edid_switcheroo() in lieu of drm_get_edid() on LVDS
if the vga_switcheroo handler is capable of temporarily switching
the panel's DDC lines to the integrated GPU. This allows us to
retrieve the EDID if the panel is currently muxed to the discrete GPU.

This only enables EDID probing on the pre-retina MBP (2008 - 2013).
The retina MBP (2012 - present) uses eDP and gmux is not capable of
switching AUX separately from the main link on these models.
This will be addressed in later patches.

List of pre-retina MBPs with dual GPUs, one of them Intel:
    [MBP  6,2 2010  intel ILK + nvidia GT216  pre-retina  15"]
    [MBP  6,1 2010  intel ILK + nvidia GT216  pre-retina  17"]
    [MBP  8,2 2011  intel SNB + amd turks     pre-retina  15"]
    [MBP  8,3 2011  intel SNB + amd turks     pre-retina  17"]
    [MBP  9,1 2012  intel IVB + nvidia GK107  pre-retina  15"]

v3: Commit newly added due to introduction of drm_get_edid_switcheroo()
    wrapper which drivers need to opt-in to.

v5: Rebase on "vga_switcheroo: Add handler flags infrastructure",
    i.e. call drm_get_edid_switcheroo() only if the handler
    indicates that DDC is switchable.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=88861
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=61115Tested-by: NLukas Wunner <lukas@wunner.de>
    [MBP  9,1 2012  intel IVB + nvidia GK107  pre-retina  15"]
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/bb095e14a2259be7fdd10092f9d6874a9be8f27b.1452525860.git.lukas@wunner.de

Originally by Seth Forshee <seth.forshee@canonical.com>, 2012-10-04:
    Some dual graphics machines support muxing the DDC separately from
    the display, so make use of this functionality when reading the EDID
    on the inactive GPU. Also serialize drm_get_edid() with a mutex to
    avoid races on the DDC mux state.

Modified by Dave Airlie <airlied@gmail.com>, 2012-12-22:
    I can't figure out why I didn't like this, but I rewrote this [...]
    to lock/unlock the ddc lines [...]. I think I'd prefer something
    like that otherwise the interface got really ugly.

Modified by Lukas Wunner <lukas@wunner.de>, 2015-04 - 2015-09:
    v3:   Move vga_switcheroo calls to a wrapper around drm_get_edid()
          which drivers can call on muxed machines. This avoids other
          drivers having to go through the vga_switcheroo motions even
          though they are never used on a muxed platform
          (Thierry Reding, Daniel Vetter, Alex Deucher)

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=88861
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=61115Tested-by: NPierre Moreau <pierre.morrow@free.fr>
    [MBP  5,3 2009  nvidia MCP79 + G96        pre-retina  15"]
Tested-by: NWilliam Brown <william@blackhats.net.au>
    [MBP  8,2 2011  intel SNB + amd turks     pre-retina  15"]
Tested-by: NLukas Wunner <lukas@wunner.de>
    [MBP  9,1 2012  intel IVB + nvidia GK107  pre-retina  15"]
Cc: Seth Forshee <seth.forshee@canonical.com>
Cc: Dave Airlie <airlied@gmail.com>
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/b898d0da4c134f2642d0122479006863e1830723.1452525860.git.lukas@wunner.de

Originally by Seth Forshee <seth.forshee@canonical.com>, 2012-10-04:
    The gmux allows muxing the DDC independently from the display, so
    support this functionality. This will allow reading the EDID for the
    inactive GPU, fixing issues with machines that either don't have a
    VBT or have invalid mode data in the VBT.

Modified by Lukas Wunner <lukas@wunner.de>, 2015-04 - 2015-12:
    Change semantics of ->switch_ddc handler callback to return previous
    DDC owner. Original version tried to determine previous DDC owner
    with find_active_client() in vga_switcheroo but this fails if the
    inactive client registers before the active client.

    v2.4: Retain semantics of ->switchto handler callback to switch all
          pins, including DDC (Daniel Vetter)

    v4:   Advertise ->switch_ddc handler callback only on the pre-retina
          Macbook Pro. The retina uses eDP instead of LVDS and gmux no
          longer does the muxing itself but merely controls an external
          mux. That mux is incapable of switching the AUX channel
          separately from the main link. It's an NXP CBTL06142
          (alternate parts: TI HD3SS212, Pericom PI3VDP12412,
          see datasheets below).

    v5:   Rebase on "apple-gmux: Track switch state".
          Rebase on "vga_switcheroo: Add handler flags infrastructure".
          Rebase on 5d170139 ("Constify vga_switcheroo_handler"),
          requires 2 structs, 1x with ->switchto for pre-retinas,
          1x without for retinas).
          Add error message if handler registration with vga_switcheroo
          fails.

    Teardowns identifying the mux:
    http://www.electronicproducts.com/-whatsinside_text-145.aspx
    http://slideshare.net/jjwu6266/apple-2012-wwdc-apple-macbook-pro-with-retina-display
    http://www.techrepublic.com/blog/cracking-open/teardown-shows-retina-macbook-pro-is-nearly-impossible-to-upgrade-difficult-to-work-on/

    Mux Datasheets:
    http://www.nxp.com/documents/data_sheet/CBTL06141.pdf
    http://www.ti.com/lit/ds/symlink/hd3ss212.pdf
    https://www.pericom.com/assets/Datasheets/PI3VDP12412.pdf

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=88861
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=61115Tested-by: NLukas Wunner <lukas@wunner.de>
    [MBP  9,1 2012  intel IVB + nvidia GK107  pre-retina  15"]
Cc: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Reviewed-by: NDarren Hart <dvhart@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/17fe8bfb0415d713bb4174f84ac9aae5d7d9a5f8.1452525860.git.lukas@wunner.de

gmux has 3 switch registers:

* GMUX_PORT_SWITCH_DISPLAY switches the panel
* GMUX_PORT_SWITCH_DDC switches the panel's DDC lines
  (only on pre-retinas; on retinas this is a no-op)
* GMUX_PORT_SWITCH_EXTERNAL switches the external DP port(s)
  (only on models without Thunderbolt, i.e. introduced before 2011;
  those with Thunderbolt switch only HPD/AUX, not the main link)

Currently we switch all 3 registers in unison.

gmux does not preserve the switch state during suspend, so we currently
read GMUX_PORT_SWITCH_DISPLAY before suspend and restore all 3 registers
to this value on resume.

With the upcoming ->switch_ddc callback, GMUX_PORT_SWITCH_DDC may
temporarily contain a different value than the other 2 registers.
If we happen to suspend at this moment, we'll write an incorrect
value to GMUX_PORT_SWITCH_DDC on resume.

Also, on models with Thunderbolt the integrated GPU is unable to drive
the external DP port(s), so we want to keep GMUX_PORT_SWITCH_EXTERNAL
permanently switched to the discrete GPU on those machines.

Consequently we can no longer assume that GMUX_PORT_SWITCH_DISPLAY
represents the correct value for all 3 registers on suspend.

Track the state of all 3 registers: Add gmux_read_switch_state() and
gmux_write_switch_state(). Instead of reading the switch state on
every suspend, read it once on driver initialization so that we know
the current switch state all the time. (This allows us to use some
optimizations and shortcuts, e.g. we can skip switching DDC if we
know that it's already switched to the requested GPU.) Change the
->switchto callback to use gmux_write_switch_state().
Tested-by: NLukas Wunner <lukas@wunner.de>
    [MBP  9,1 2012  intel IVB + nvidia GK107  pre-retina  15"]
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Reviewed-by: NDarren Hart <dvhart@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/5679f414cb0ddf1654dcc359571f3764b275edf0.1452525860.git.lukas@wunner.de

Originally by Seth Forshee <seth.forshee@canonical.com>, 2012-10-04:
    During graphics driver initialization it's useful to be able to mux
    only the DDC to the inactive client in order to read the EDID. Add
    a switch_ddc callback to allow capable handlers to provide this
    functionality, and add vga_switcheroo_switch_ddc() to allow DRM
    to mux only the DDC.

Modified by Dave Airlie <airlied@gmail.com>, 2012-12-22:
    I can't figure out why I didn't like this, but I rewrote this [...]
    to lock/unlock the ddc lines [...]. I think I'd prefer something
    like that otherwise the interface got really ugly.

Modified by Lukas Wunner <lukas@wunner.de>, 2015-04 - 2015-10:
    Change semantics of ->switch_ddc handler callback to return previous
    DDC owner. Original version tried to determine previous DDC owner
    with find_active_client() but this fails if the inactive client
    registers before the active client.

    Don't lock vgasr_mutex in _lock_ddc() / _unlock_ddc(), it can cause
    deadlocks because (a) during switch (with vgasr_mutex already held),
    GPU is woken and probes its outputs, tries to re-acquire vgasr_mutex
    to lock DDC lines; (b) Likewise during switch, GPU is suspended and
    calls cancel_delayed_work_sync() to stop output polling, if poll
    task is running at this moment we may wait forever for it to finish.

    Instead, lock mux_hw_lock when unregistering the handler because
    the only reason why we'd want to lock vgasr_mutex in _lock_ddc() /
    _unlock_ddc() is to block the handler from disappearing while DDC
    lines are switched.

    Also acquire mux_hw_lock in stage2 to avoid race condition where
    reading the EDID and switching happens simultaneously. Likewise on
    MIGD / MDIS commands and on runtime suspend.

    v2.1: Overhaul locking, squash commits (Daniel Vetter)

    v2.2: Readability improvements (Thierry Reding)

    v2.3: Overhaul locking once more

    v2.4: Retain semantics of ->switchto handler callback to switch all
          pins, including DDC (Daniel Vetter)

    v5:   Rename ddc_lock to mux_hw_lock: Since we acquire this both
          when calling ->switch_ddc and ->switchto, it protects not just
          access to the DDC lines but to the mux in general. This is in
          line with the DRM convention to use low-level locks to avoid
          concurrent hw access (e.g. i2c, dp_aux) which are often called
          hw_lock (Daniel Vetter)

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=88861
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=61115Tested-by: NLukas Wunner <lukas@wunner.de>
    [MBP  9,1 2012  intel IVB + nvidia GK107  pre-retina  15"]
Cc: Seth Forshee <seth.forshee@canonical.com>
Cc: Dave Airlie <airlied@gmail.com>
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/e81ae9722b84c5ed591805fee3ea6dbf5dc6c4b3.1452525860.git.lukas@wunner.de

Allow handlers to declare their capabilities and allow clients to
obtain that information. So far we have these use cases:

* If the handler is able to switch DDC separately, clients need to
  probe EDID with drm_get_edid_switcheroo(). We should allow them
  to detect a capable handler to ensure this function only gets
  called when needed.

* Likewise if the handler is unable to switch AUX separately, the active
  client needs to communicate link training parameters to the inactive
  client, which may then skip the AUX handshake and set up its output
  with these pre-calibrated values (DisplayPort specification v1.1a,
  section 2.5.3.3). Clients need a way to recognize such a situation.

The flags for the radeon_atpx_handler and amdgpu_atpx_handler are
initially set to 0, this can later on be amended with
  handler_flags |= VGA_SWITCHEROO_CAN_SWITCH_DDC;
when a ->switch_ddc callback is added.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=88861
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=61115Tested-by: NLukas Wunner <lukas@wunner.de>
    [MBP  9,1 2012  intel IVB + nvidia GK107  pre-retina  15"]
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Reviewed-by: NDarren Hart <dvhart@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/2b0d93ed6e511ca09e95e45e0b35627f330fabce.1452525860.git.lukas@wunner.de

This allows iteration over encoders without requiring connection_mutex.

Changes since v1:
- Add a set_best_encoder helper function and update encoder_mask inside
  it.
Changes since v2:
- Relax the WARN_ON(!crtc), with explanation.
- Call set_best_encoder when connector is moved between crtc's.
- Add some paranoia to steal_encoder to prevent accidentally setting
  best_encoder to NULL.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/56AA200A.6070501@linux.intel.com

While we steal the encoder away from the connector the connector may
be updated to use a different encoder.

Without this change if 2 connectors swap encoders one of them will
end up without a crtc.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1452160762-30487-5-git-send-email-maarten.lankhorst@linux.intel.com