1. 23 May, 2016 2 commits
    • Ville Syrjälä's avatar
      drm/i915: Respect DP++ adaptor TMDS clock limit · c578d152
      Ville Syrjälä authored
      Try to detect the max TMDS clock limit for the DP++ adaptor (if any)
      and take it into account when checking the port clock.
      
      Note that as with the sink (HDMI vs. DVI) TMDS clock limit we'll ignore
      the adaptor TMDS clock limit in the modeset path, in case users are
      already "overclocking" their TMDS links. One subtle change here is that
      we'll have to respect the adaptor TMDS clock limit when we decide whether
      to do 12bpc or 8bpc, otherwise we might end up picking 12bpc and
      accidentally driving the TMDS link out of spec even when the user chose
      a mode that fits wihting the limits at 8bpc. This means you can't
      "overclock" your DP++ dongle at 12bpc anymore, but you can continue to
      do so at 8bpc.
      
      Note that for simplicity we'll use the I2C access method for all dual
      mode adaptors including type 2. Otherwise we'd have to start mixing
      DP AUX and HDMI together. In the future we may need to do that if we
      come across any board designs that don't hook up the DDC pins to the
      DP++ connectors. Such boards would obviously only work with type 2
      dual mode adaptors, and not type 1.
      
      v2: Store adaptor type under indel_hdmi->dp_dual_mode
          Deal with DRM_DP_DUAL_MODE_UNKNOWN
          Pass adaptor type to drm_dp_dual_mode_max_tmds_clock(),
          and use it for type1 adaptors as well
      
      Cc: stable@vger.kernel.org
      Reported-by: default avatarTore Anderson <tore@fud.no>
      Fixes: 7a0baa62 ("Revert "drm/i915: Disable 12bpc hdmi for now"")
      Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
      Cc: Shashank Sharma <shashank.sharma@intel.com>
      Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
      Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
      Link: http://patchwork.freedesktop.org/patch/msgid/1462216105-20881-3-git-send-email-ville.syrjala@linux.intel.comReviewed-by: default avatarShashank Sharma <shashank.sharma@intel.com>
      (cherry picked from commit b1ba124d)
      Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
      c578d152
    • Ville Syrjälä's avatar
      drm: Add helper for DP++ adaptors · b3daa5ef
      Ville Syrjälä authored
      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: default avatarVille 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
      (cherry picked from commit ede53344)
      Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
      b3daa5ef
  2. 25 Apr, 2016 1 commit
  3. 24 Apr, 2016 3 commits
  4. 22 Apr, 2016 10 commits
  5. 21 Apr, 2016 1 commit
  6. 20 Apr, 2016 11 commits
  7. 19 Apr, 2016 12 commits