This series implement support to a drm_dp_aux chardev that allows reading and writing an arbitrary amount of bytes to arbitrary dpcd register addresses using regular read, write and lseek operations.
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
Rafael Antognolli (2): drm/dp: Add a drm_aux-dev module for reading/writing dpcd registers. drm/dp: Set aux.dev to the drm_connector device, instead of drm_device.
drivers/gpu/drm/Kconfig | 8 + drivers/gpu/drm/Makefile | 1 + drivers/gpu/drm/drm_dp_aux_dev.c | 381 +++++++++++++++++++++++++++++++++++++++ drivers/gpu/drm/drm_dp_helper.c | 5 + drivers/gpu/drm/i915/intel_dp.c | 19 +- include/drm/drm_dp_aux_dev.h | 50 +++++ 6 files changed, 447 insertions(+), 17 deletions(-) create mode 100644 drivers/gpu/drm/drm_dp_aux_dev.c create mode 100644 include/drm/drm_dp_aux_dev.h