LSPCON is essentially a dp++->hdmi adapter with dual mode of operation.
These modes are:
- Level Shifter mode: In LS mode, this device works as a type2 dp->hdmi
passive dongle, which steps up DP++ output to appropriate HDMI 1.4 signal.
This mode doesn't do any conversion at the protocol level.
- Protocol Converter mode: In PCON mode, this device acts as an
active DP++->HDMI 2.0 dongle, which converts the DP++ output to
compatible HDMI 2.0 output. In PCON mode, lspcon can support 4k@60
outputs, using DP HBR2 mode.
Many of Intel GEN9 devices come with in-built lspcon card
in motherboartd down mode. This patch series adds support for
lspcon devices in I915 driver.
While unit-testing this code, I was able to see a 4k@60 modeset with:
- BXT-T board
- Single HDMI 4k@60 display (ACER S)
- Ubuntu 14.04 desktop
V2: Worked on review comments from Ville
- In general, Ville suggested not to use the dual personality of
DDI to drive lspcon, so this patch set drives it just as DP++ display.
There is no separate detection for lspcon (hpd_pulse is good enough), and
its being driven as a DP display with special initialization and EDID
read sequence. To be able to do this, we driving lspcon in PCON mode only,
where it can serve both HDMI1.3/HDMI1.4 sinks as well as 4k@60 capable
HDMI 2.0 sinks. So compared to previous series, there is one patch less,
as we have dropped lspcon detection patch.
V3: Addressed review comments from Rodrigo
Details available with respective patch.
V4: Addressed review comments from Ville
Details available with respective patch.
V5: Rebase, added a new patch for suspend/resume
Shashank Sharma (5):
drm: Helper for lspcon in drm_dp_dual_mode
drm/i915: Add lspcon support for I915 driver
drm/i915: Parse VBT data for lspcon
drm/i915: Enable lspcon initialization
drm/i915: Add lspcon resume function
drivers/gpu/drm/drm_dp_dual_mode_helper.c | 103 +++++++++++++++++++
drivers/gpu/drm/i915/Makefile | 1 +
drivers/gpu/drm/i915/i915_drv.c | 2 +
drivers/gpu/drm/i915/i915_drv.h | 5 +
drivers/gpu/drm/i915/intel_bios.c | 49 +++++++++
drivers/gpu/drm/i915/intel_ddi.c | 29 +++++-
drivers/gpu/drm/i915/intel_drv.h | 10 ++
drivers/gpu/drm/i915/intel_lspcon.c | 165 ++++++++++++++++++++++++++++++
include/drm/drm_dp_dual_mode_helper.h | 26 +++++
9 files changed, 389 insertions(+), 1 deletion(-)
create mode 100644 drivers/gpu/drm/i915/intel_lspcon.c
--
1.9.1
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