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path: root/drivers/gpu/drm/drm_dp_aux_dev.c
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2020-01-09drm/dp_mst: Add MST support to DP DPCD R/W functionsDavid Francis
Instead of having drm_dp_dpcd_read/write and drm_dp_mst_dpcd_read/write as entry points into the aux code, have drm_dp_dpcd_read/write handle both. This means that DRM drivers can make MST DPCD read/writes. v2: Fix spacing v3: Dump dpcd access on MST read/writes v4: Fix calling wrong function on DPCD write v5: delete deprecated include of drmP.h Reviewed-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Harry Wentland <harry.wentland@amd.com> Signed-off-by: David Francis <David.Francis@amd.com> Signed-off-by: Mikita Lipski <mikita.lipski@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2019-07-25drm/dp_mst: Enable registration of AUX devices for MST portsVille Syrjälä
All available downstream ports - physical and logical - are exposed for each MST device. They are listed in /dev/, following the same naming scheme as SST devices by appending an incremental ID. Although all downstream ports are exposed, only some will work as expected. Consider the following topology: +---------+ | ASIC | +---------+ Conn-0| | +----v----+ +----| MST HUB |----+ | +---------+ | | | |Port-1 Port-2| +-----v-----+ +-----v-----+ | MST | | SST | | Display | | Display | +-----------+ +-----------+ |Port-1 x MST Path | MST Device ----------+---------------------------------- sst:0 | MST Hub mst:0-1 | MST Display mst:0-1-1 | MST Display's disconnected DP out mst:0-1-8 | MST Display's internal sink mst:0-2 | SST Display On certain MST displays, the upstream physical port will ACK DPCD reads. However, reads on the local logical port to the internal sink will *NAK*. i.e. reading mst:0-1 ACKs, but mst:0-1-8 NAKs. There may also be duplicates. Some displays will return the same GUID when reading DPCD from both mst:0-1 and mst:0-1-8. There are some device-dependent behavior as well. The MST hub used during testing will actually *ACK* read requests on a disconnected physical port, whereas the MST displays will NAK. In light of these discrepancies, it's simpler to expose all downstream ports - both physical and logical - and let the user decide what to use. v3 changes: * Change WARN_ON_ONCE -> DRM_ERROR on dpcd read errors * Docstring and cosmetic fixes v2 changes: Moved remote aux device (un)registration to new mst connector late register and early unregister helpers. Drivers should call these from their own mst connector function hooks. This is to solve an issue during driver unload, where mst connector devices are unregistered before the remote aux devices are. In a setup where aux devices are created as children of connector devices, the aux device would be removed too early, and uncleanly. Doing so in early_unregister solves this issue, as that is called before connector unregistration. Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Leo Li <sunpeng.li@amd.com> Reviewed-by: Lyude Paul <lyude@redhat.com> Signed-off-by: Harry Wentland <harry.wentland@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190723232808.28128-3-sunpeng.li@amd.com
2019-07-25drm/dp: Use non-cyclic idrLeo Li
In preparation for adding aux devices for DP MST, make the IDR non-cyclic. That way, hotplug cycling MST devices won't needlessly increment the minor version index. Signed-off-by: Leo Li <sunpeng.li@amd.com> Reviewed-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Harry Wentland <harry.wentland@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190723232808.28128-2-sunpeng.li@amd.com
2019-05-06drm/dp: drmP.h include removalJani Nikula
Continue to get rid of drmP.h. Add minimal includes to build. Sort includes while at it. Reviewed-by: Noralf Trønnes <noralf@tronnes.org> Signed-off-by: Jani Nikula <jani.nikula@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190506095248.20874-1-jani.nikula@intel.com
2018-03-20sched/wait, drivers/drm: Convert wait_on_atomic_t() usage to the new ↵Peter Zijlstra
wait_var_event() API The old wait_on_atomic_t() is going to get removed, use the more flexible wait_var_event() API instead. Unlike wake_up_atomic_t(), wake_up_var() will issue the wakeup even if the variable is not 0. No change in functionality. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: David Airlie <airlied@linux.ie> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-13Pass mode to wait_on_atomic_t() action funcs and provide default actionsDavid Howells
Make wait_on_atomic_t() pass the TASK_* mode onto its action function as an extra argument and make it 'unsigned int throughout. Also, consolidate a bunch of identical action functions into a default function that can do the appropriate thing for the mode. Also, change the argument name in the bit_wait*() function declarations to reflect the fact that it's the mode and not the bit number. [Peter Z gives this a grudging ACK, but thinks that the whole atomic_t wait should be done differently, though he's not immediately sure as to how] Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> cc: Ingo Molnar <mingo@kernel.org>
2017-07-08drm_dp_aux_dev: switch to read_iter/write_iterAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-08-16drm: Don't export dp-aux devnode functionsDaniel Vetter
They're only used internally within the dp helpers. Also nuke the kerneldoc (we only document the driver interface in the drm shared functions). And move the header file from the public include/ directory to the source files into drm_crtc_helper_internal.h, similar to how we already have drm_crtc_internal.h. While at it also move drm_fb_helper_modinit since that belongs in there, too. I noticed this all since I spotted kerneldoc which wasn't pulled into the rst templates. v2: Update Copyright date. Cc: Sean Paul <seanpaul@chromium.org> Cc: Rafael Antognolli <rafael.antognolli@intel.com> Reviewed-by: Sean Paul <seanpaul@chromium.org> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1471034937-651-16-git-send-email-daniel.vetter@ffwll.ch
2016-07-12drm_aux-dev: fix error handling in drm_dp_aux_dev_init()Alexey Khoroshilov
If class_create() fails, there is no need for class_destroy(). Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1467237135-13075-1-git-send-email-khoroshilov@ispras.ru
2016-04-28drm/dp: Allow signals to interrupt drm_aux-dev reads/writesVille Syrjälä
Let's be nice and interrupt the dpcd aux-dev reads/writes when there's a signal pending. Much nicer if the user can hit ^C instead of having to sit around waiting for the read/write to finish. time dd if=/dev/drm_dp_aux0 bs=$((1024*1024)) ^C before: real 0m34.681s user 0m0.003s sys 0m6.880s after: real 0m0.222s user 0m0.006s sys 0m0.057s Cc: Rafael Antognolli <rafael.antognolli@intel.com> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1461786225-7790-1-git-send-email-ville.syrjala@linux.intel.com
2016-02-12drm/dp: Add a drm_aux-dev module for reading/writing dpcd registers.Rafael Antognolli
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: Rafael Antognolli <rafael.antognolli@intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1453417821-2811-3-git-send-email-rafael.antognolli@intel.com