Especially document the assumptions and semantics of the callbacks
carefully. Just a warm-up excercise really.
v2: Spelling fixes (Eric).
v3: Consolidate more with existing docs:
- Remove the overview section explaining the bridge funcs, that's
now all in the drm_bridge_funcs kerneldoc in much more detail.
- Use & to reference structs so that kerneldoc automatically inserts
hyperlinks.
v4: Review from Thierry.
Cc: Eric Anholt <eric@anholt.net>
Cc: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Archit Taneja <architt@codeaurora.org> (v3)
Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-7-git-send-email-daniel.vetter@ffwll.ch
Reviewed-by: Thierry Reding <treding@nvidia.com>
Add DOC sections giving an overview of drm_bridge and how to fill up the
drm_bridge_funcs ops. Add these to drm.tpml in DocBook.
Add headerdocs for funcs in drm_bridge.c that don't have them yet.
Signed-off-by: Archit Taneja <architt@codeaurora.org>
[danvet: Amend kerneldoc as discussed with Archit.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Allow drm_bridge objects to link to each other in order to form an encoder
chain. The requirement for creating a chain of bridges comes because the
MSM drm driver uses up its encoder and bridge objects for blocks within
the SoC itself. There isn't anything left to use if the SoC display output
is connected to an external encoder IC. Having an additional bridge
connected to the existing bridge helps here. In general, it is possible for
platforms to have multiple devices between the encoder and the
connector/panel that require some sort of configuration.
We create drm bridge helper functions corresponding to each op in
'drm_bridge_funcs'. These helpers call the corresponding
'drm_bridge_funcs' op for the entire chain of bridges. These helpers are
used internally by drm_atomic_helper.c and drm_crtc_helper.c.
The drm_bridge_enable/pre_enable helpers execute enable/pre_enable ops of
the bridge closet to the encoder, and proceed until the last bridge in the
chain is enabled. The same holds for drm_bridge_mode_set/mode_fixup
helpers. The drm_bridge_disable/post_disable helpers disable the last
bridge in the chain first, and proceed until the first bridge in the chain
is disabled.
drm_bridge_attach() remains the same. As before, the driver calling this
function should make sure it has set the links correctly. The order in
which the bridges are connected to each other determines the order in which
the calls are made. One requirement is that every bridge in the chain
should point the parent encoder object. This is required since bridge
drivers expect a valid encoder pointer in drm_bridge. For example, consider
a chain where an encoder's output is connected to bridge1, and bridge1's
output is connected to bridge2:
/* Like before, attach bridge to an encoder */
bridge1->encoder = encoder;
ret = drm_bridge_attach(dev, bridge1);
..
/*
* set the first bridge's 'next' bridge to bridge2, set its encoder
* as bridge1's encoder
*/
bridge1->next = bridge2
bridge2->encoder = bridge1->encoder;
ret = drm_bridge_attach(dev, bridge2);
...
...
This method of bridge chaining isn't intrusive and existing drivers that
use drm_bridge will behave the same way as before. The bridge helpers also
cleans up the atomic and crtc helper files a bit.
Reviewed-by: Jani Nikula <jani.nikula@linux.intel.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
../drivers/gpu/drm/drm_vm.c:405:6: warning: symbol 'drm_vm_open_locked' was not declared. Should it be static?
../drivers/gpu/drm/drm_vm.c:431:6: warning: symbol 'drm_vm_close_locked' was not declared. Should it be static?
../drivers/gpu/drm/drm_vm.c:681:5: warning: symbol 'drm_vma_info' was not declared. Should it be static?
../drivers/gpu/drm/drm_pci.c:146:5: warning: symbol 'drm_pci_set_unique' was not declared. Should it be static?
../drivers/gpu/drm/drm_pci.c:216:5: warning: symbol 'drm_irq_by_busid' was not declared. Should it be static?
../drivers/gpu/drm/drm_info.c:47:5: warning: symbol 'drm_name_info' was not declared. Should it be static?
../drivers/gpu/drm/drm_info.c:72:5: warning: symbol 'drm_vm_info' was not declared. Should it be static?
../drivers/gpu/drm/drm_info.c:116:5: warning: symbol 'drm_bufs_info' was not declared. Should it be static?
../drivers/gpu/drm/drm_info.c:159:5: warning: symbol 'drm_clients_info' was not declared. Should it be static?
../drivers/gpu/drm/drm_info.c:209:5: warning: symbol 'drm_gem_name_info' was not declared. Should it be static?
../drivers/gpu/drm/drm_ioc32.c:1019:20: warning: symbol 'drm_compat_ioctls' was not declared. Should it be static?
../drivers/gpu/drm/drm_bridge.c:52:12: warning: function 'drm_bridge_attach' with external linkage has definition
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Currently, third party bridge drivers(ptn3460) are dependent
on the corresponding encoder driver init, since bridge driver
needs a drm_device pointer to finish drm initializations.
The encoder driver passes the drm_device pointer to the
bridge driver. Because of this dependency, third party drivers
like ptn3460 doesn't adhere to the driver model.
In this patch, we reframe the bridge registration framework
so that bridge initialization is split into 2 steps, and
bridge registration happens independent of drm flow:
--Step 1: gather all the bridge settings independent of drm and
add the bridge onto a global list of bridges.
--Step 2: when the encoder driver is probed, call drm_bridge_attach
for the corresponding bridge so that the bridge receives
drm_device pointer and continues with connector and other
drm initializations.
The old set of bridge helpers are removed, and a set of new helpers
are added to accomplish the 2 step initialization.
The bridge devices register themselves onto global list of bridges
when they get probed by calling "drm_bridge_add".
The parent encoder driver waits till the bridge is available
in the lookup table(by calling "of_drm_find_bridge") and then
continues with its initialization.
The encoder driver should also call "drm_bridge_attach" to pass
on the drm_device to the bridge object.
drm_bridge_attach inturn calls "bridge->funcs->attach" so that
bridge can continue with drm related initializations.
Signed-off-by: Ajay Kumar <ajaykumar.rs@samsung.com>
Acked-by: Inki Dae <inki.dae@samsung.com>
Tested-by: Rahul Sharma <rahul.sharma@samsung.com>
Tested-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Tested-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Signed-off-by: Thierry Reding <treding@nvidia.com>
