linux/include
Rafael Antognolli e94cb37b34 drm/dp: Add a drm_aux-dev module for reading/writing dpcd registers.
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
2016-02-12 14:22:40 +01:00
..
acpi ACPI / CPPC: remove redundant mbox_send_message() declaration 2016-02-03 01:09:52 +01:00
asm-generic Merge branch 'akpm' (patches from Andrew) 2016-01-21 12:32:08 -08:00
clocksource
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2016-01-22 11:58:43 -08:00
drm drm/dp: Add a drm_aux-dev module for reading/writing dpcd registers. 2016-02-12 14:22:40 +01:00
dt-bindings ARM: SoC driver updates for v4.5 2016-01-20 18:42:30 -08:00
keys
kvm
linux apple-gmux: Fix build breakage if !CONFIG_ACPI 2016-02-11 09:23:59 +01:00
math-emu
media [media] vb2: fix nasty vb2_thread regression 2016-02-04 09:13:46 -02:00
memory
misc
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-02-01 15:56:08 -08:00
pcmcia
ras
rdma IB/mlx4: Enable send of RoCE QP1 packets with IP/UDP headers 2016-01-19 15:35:01 -05:00
rxrpc
scsi Initial roundup of 4.5 merge window patches 2016-01-23 18:45:06 -08:00
soc ARM: SoC driver updates for v4.5 2016-01-20 18:42:30 -08:00
sound ALSA: rawmidi: Make snd_rawmidi_transmit() race-free 2016-02-03 14:51:28 +01:00
target Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2016-01-20 17:20:53 -08:00
trace This includes three minor fixes, mostly due to cut-and-paste issues. 2016-01-28 17:00:50 -08:00
uapi drm: prime: Honour O_RDWR during prime-handle-to-fd 2016-02-09 09:25:12 +01:00
video
xen Merge branch 'for-4.5/drivers' of git://git.kernel.dk/linux-block 2016-01-21 18:19:38 -08:00
Kbuild