Since we're about to be using drm_dbg_*() throughout the DP helpers, we'll
need to be able to access the DRM device in the dual mode DP helpers as
well. Note however that since drm_dp_dual_mode_detect() can be called with
DDC adapters that aren't part of a drm_dp_aux struct, we need to pass down
the drm_device to these functions instead of using drm_dp_aux.
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210423184309.207645-9-lyude@redhat.com
Reviewed-by: Dave Airlie <airlied@redhat.com>
This patch adds lspcon support in dp_dual_mode helper.
lspcon is essentially a dp->hdmi dongle with dual personality.
LS mode: It works as a passive dongle, by level shifting DP++
signals to HDMI signals, in LS mode.
PCON mode: It works as a protocol converter active dongle
in pcon mode, by converting DP++ outputs to HDMI 2.0 outputs.
This patch adds support for lspcon detection and mode set
switch operations, as a dp dual mode dongle.
v2: Addressed review comments from Ville
- add adaptor id for lspcon devices (0x08), use it to identify lspcon
- change function names
old: drm_lspcon_get_current_mode/drm_lspcon_change_mode
new: drm_lspcon_get_mode/drm_lspcon_set_mode
- change drm_lspcon_get_mode type to int, to match
drm_dp_dual_mode_get_tmds_output
- change 'err' to 'ret' to match the rest of the functions
- remove pointless typecasting during call to dual_mode_read
- fix the but while setting value of data, while writing lspcon mode
- fix indentation
- change mdelay(10) -> msleep(10)
- return ETIMEDOUT instead of EFAULT, when lspcon mode change times out
- Add an empty line to separate std regs macros and lspcon regs macros
Indent bit definition
v3: Addressed review comments from Rodrigo
- change macro name from DP_DUAL_MODE_TYPE_LSPCON to
DP_DUAL_MODE_TYPE_HAS_DPCD for better readability
- change macro name from DP_DUAL_MODE_LSPCON_MODE_PCON to
DP_DUAL_MODE_LSPCON_MODE_PCON for better readability
- add comment for MCA specific offsets like 0x40 and 0x41
- remove DP_DUAL_MODE_REV_TYPE2 check while checking lspcon adapter id
v4: Addressed review comments from Ville
- Fixed indentation at few places
- s/current_mode/mode
- s/reqd_mode/mode
- remove unnecessary void* cast
- remove drm_edid.h from includes
- Add a comment for _HAS_DPCD
- Fix enum description, for lspcon_mode.
v5: Rebase
v6: Rebase
Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Dave Airlie <airlied@gmail.com>
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1476720277-16298-1-git-send-email-shashank.sharma@intel.com
Add a helper which aids in the identification of DP dual mode
(aka. DP++) adaptors. There are several types of adaptors
specified: type 1 DVI, type 1 HDMI, type 2 DVI, type 2 HDMI
Type 1 adaptors have a max TMDS clock limit of 165MHz, type 2 adaptors
may go as high as 300MHz and they provide a register informing the
source device what the actual limit is. Supposedly also type 1 adaptors
may optionally implement this register. This TMDS clock limit is the
main reason why we need to identify these adaptors.
Type 1 adaptors provide access to their internal registers and the sink
DDC bus through I2C. Type 2 adaptors provide this access both via I2C
and I2C-over-AUX. A type 2 source device may choose to implement either
of these methods. If a source device implements the I2C-over-AUX
method, then the driver will obviously need specific support for such
adaptors since the port is driven like an HDMI port, but DDC
communication happes over the AUX channel.
This helper should be enough to identify the adaptor type (some
type 1 DVI adaptors may be a slight exception) and the maximum TMDS
clock limit. Another feature that may be available is control over
the TMDS output buffers on the adaptor, possibly allowing for some
power saving when the TMDS link is down.
Other user controllable features that may be available in the adaptors
are downstream i2c bus speed control when using i2c-over-aux, and
some control over the CEC pin. I chose not to provide any helper
functions for those since I have no use for them in i915 at this time.
The rest of the registers in the adaptor are mostly just information,
eg. IEEE OUI, hardware and firmware revision, etc.
v2: Pass adaptor type to helper functions to ease driver implementation
Fix a bunch of typoes (Paulo)
Add DRM_DP_DUAL_MODE_UNKNOWN for the case where we don't (yet) know
the type (Paulo)
Reject 0x00 and 0xff DP_DUAL_MODE_MAX_TMDS_CLOCK values (Paulo)
Adjust drm_dp_dual_mode_detect() type2 vs. type1 detection to
ease future LSPCON enabling
Remove the unused DP_DUAL_MODE_LAST_RESERVED define
v3: Fix kernel doc function argument descriptions (Jani)
s/NONE/UNKNOWN/ in drm_dp_dual_mode_detect() docs
Add kernel doc for enum drm_dp_dual_mode_type
Actually build the docs
Fix more typoes
v4: Adjust code indentation of type2 adaptor detection (Shashank)
Add debug messages for failurs cases (Shashank)
v5: EXPORT_SYMBOL(drm_dp_dual_mode_read) (Paulo)
Cc: stable@vger.kernel.org
Cc: Tore Anderson <tore@fud.no>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Shashank Sharma <shashank.sharma@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Shashank Sharma <shashank.sharma@intel.com> (v4)
Link: http://patchwork.freedesktop.org/patch/msgid/1462542412-25533-1-git-send-email-ville.syrjala@linux.intel.com
