drm/edid: detect SCDC support in HF-VSDB

This patch does following:
- Adds a new structure (drm_hdmi_info) in drm_display_info.
  This structure will be used to save and indicate if sink
  supports advanced HDMI 2.0 features
- Adds another structure drm_scdc within drm_hdmi_info, to
  reflect scdc support and capabilities in connected HDMI 2.0 sink.
- Checks the HF-VSDB block for presence of SCDC, and marks it
  in scdc structure
- If SCDC is present, checks if sink is capable of generating
  SCDC read request, and marks it in scdc structure.

V2: Addressed review comments
  Thierry:
  - Fix typos in commit message and make abbreviation consistent
    across the commit message.
  - Change structure object name from hdmi_info -> hdmi
  - Fix typos and abbreviations in description of structure drm_hdmi_info
    end the description with a full stop.
  - Create a structure drm_scdc, and keep all information related to SCDC
    register set (supported, read request supported) etc in it.

  Ville:
  - Change rr -> read_request
  - Call drm_detect_scrambling function drm_parse_hf_vsdb so that all
    of HF-VSDB parsing can be kept in same function, in incremental
    patches.

V3: Rebase.
V4: Rebase.
V5: Rebase.
V6: Addressed review comments from Ville
  - Add clock rate calculations for 1/10 and 1/40 ratios
  - Remove leftovers from old patchset
V7: Added R-B from Jose.
V8: Rebase.
V9: Rebase.
V10: Rebase.

Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Jose Abreu <joabreu@synopsys.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1489404244-16608-5-git-send-email-shashank.sharma@intel.com

1 files changed, 27 insertions, 0 deletions

diff --git a/include/drm/drm_scdc_helper.h b/include/drm/drm_scdc_helper.h
index 9c52deb13df4..ab6bcfbceba9 100644
--- a/include/drm/drm_scdc_helper.h
+++ b/include/drm/drm_scdc_helper.h
@@ -129,4 +129,31 @@ static inline int drm_scdc_writeb(struct i2c_adapter *adapter, u8 offset,
 	return drm_scdc_write(adapter, offset, &value, sizeof(value));
 }
 
+/**
+ * drm_scdc_set_scrambling - enable scrambling
+ * @adapter: I2C adapter for DDC channel
+ * @enable: bool to indicate if scrambling is to be enabled/disabled
+ *
+ * Writes the TMDS config register over SCDC channel, and:
+ * enables scrambling when enable = 1
+ * disables scrambling when enable = 0
+ *
+ * Returns:
+ * True if scrambling is set/reset successfully, false otherwise.
+ */
+bool drm_scdc_set_scrambling(struct i2c_adapter *adapter, bool enable);
+
+/**
+ * drm_scdc_set_high_tmds_clock_ratio - set TMDS clock ratio
+ * @adapter: I2C adapter for DDC channel
+ * @set: ret or reset the high clock ratio
+ *
+ * Writes to the TMDS config register over SCDC channel, and:
+ * sets TMDS clock ratio to 1/40 when set = 1
+ * sets TMDS clock ratio to 1/10 when set = 0
+ *
+ * Returns:
+ * True if write is successful, false otherwise.
+ */
+bool drm_scdc_set_high_tmds_clock_ratio(struct i2c_adapter *adapter, bool set);
 #endif