[Intel-gfx] [PATCH] drm/i915/cnl: Map VBT DDC Pin to BSpec DDC Pin.

[Rodrigo Vivi]

On Fri, Oct 20, 2017 at 05:40:10PM +0000, Ville Syrjälä wrote:
> On Fri, Oct 20, 2017 at 10:26:41AM -0700, Rodrigo Vivi wrote:
> > Starting on CNL we now need to map VBT DDC Pin to
> > BSPec DDC Pin values. Not a direct translation anymore.
> > 
> > According to VBT
> > Block 2 (General Bytes Definition)
> > DDC Bus
> > 
> > +----------+-----------+--------------------+
> > | DDI Type | VBT Value | Bspec Mapped Value |
> > +----------+-----------+--------------------+
> > | DDI-B    | 0x1       | 0x1                |
> > | DDI-C    | 0x2       | 0x2                |
> > | DDI-D    | 0x3       | 0x4                |
> > | DDI-F    | 0x4       | 0x3                |
> > +----------+-----------+--------------------+
> > 
> > v2: Move defines to a better place.
> >     This is actually CNL_PCH not CNL only.
> > v3: Accepting Ville's suggestions: enums and array to
> >     to make this future proof.
> > v4: Protect the array access as Ville suggested.
> >     Also accepting all Jani's suggestions:
> >     	      - use already defined gmbus pin definitions.
> > 	      - use map_ddc_pin for disambiguation.
> > 	      - Add /* sic */ comment on inverted values
> > 	      	so people can easily see it it nos a mistake
> > 		we have the map 3 -> 4 and 4 -> 3 :/
> > 
> > Cc: Jani Nikula <jani.nikula at intel.com>
> > Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
> > Cc: Anusha Srivatsa <anusha.srivatsa at intel.com>
> > Cc: Clinton Taylor <clinton.a.taylor at intel.com>
> > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_bios.c     | 27 +++++++++++++++++----------
> >  drivers/gpu/drm/i915/intel_vbt_defs.h |  8 ++++++++
> >  2 files changed, 25 insertions(+), 10 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
> > index e809a9c347d3..a95cf07bd8e1 100644
> > --- a/drivers/gpu/drm/i915/intel_bios.c
> > +++ b/drivers/gpu/drm/i915/intel_bios.c
> > @@ -1071,6 +1071,22 @@ static void sanitize_aux_ch(struct drm_i915_private *dev_priv,
> >  	}
> >  }
> >  
> > +static const u8 cnp_ddc_pin_map[] = {
> > +	[DDC_BUS_DDI_B] = GMBUS_PIN_1_BXT,
> > +	[DDC_BUS_DDI_C] = GMBUS_PIN_2_BXT,
> > +	[DDC_BUS_DDI_D] = GMBUS_PIN_4_CNP, /* sic */
> > +	[DDC_BUS_DDI_F] = GMBUS_PIN_3_BXT, /* sic */
> > +};
> > +
> > +static u8 map_ddc_pin(struct drm_i915_private *dev_priv, u8 vbt_pin)
> > +{
> > +	if (HAS_PCH_CNP(dev_priv) &&
> > +	    vbt_pin > 0 && vbt_pin < ARRAY_SIZE(cnp_ddc_pin_map))
> > +		return cnp_ddc_pin_map[vbt_pin];
> 
> Not quite sure what we should do with invalid pins. But I guess this
> makes as much sense as anything.
> 
> Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

Thanks a lot for all ideas.

merged to dinq.

> 
> > +
> > +	return vbt_pin;
> > +}
> > +
> >  static void parse_ddi_port(struct drm_i915_private *dev_priv, enum port port,
> >  			   u8 bdb_version)
> >  {
> > @@ -1163,16 +1179,7 @@ static void parse_ddi_port(struct drm_i915_private *dev_priv, enum port port,
> >  		DRM_DEBUG_KMS("Port %c is internal DP\n", port_name(port));
> >  
> >  	if (is_dvi) {
> > -		info->alternate_ddc_pin = ddc_pin;
> > -
> > -		/*
> > -		 * All VBTs that we got so far for B Stepping has this
> > -		 * information wrong for Port D. So, let's just ignore for now.
> > -		 */
> > -		if (IS_CNL_REVID(dev_priv, CNL_REVID_B0, CNL_REVID_B0) &&
> > -		    port == PORT_D) {
> > -			info->alternate_ddc_pin = 0;
> > -		}
> > +		info->alternate_ddc_pin = map_ddc_pin(dev_priv, ddc_pin);
> >  
> >  		sanitize_ddc_pin(dev_priv, port);
> >  	}
> > diff --git a/drivers/gpu/drm/i915/intel_vbt_defs.h b/drivers/gpu/drm/i915/intel_vbt_defs.h
> > index 404569c9fdfc..f225c288a121 100644
> > --- a/drivers/gpu/drm/i915/intel_vbt_defs.h
> > +++ b/drivers/gpu/drm/i915/intel_vbt_defs.h
> > @@ -306,6 +306,14 @@ struct bdb_general_features {
> >  
> >  #define LEGACY_CHILD_DEVICE_CONFIG_SIZE		33
> >  
> > +/* DDC Bus DDI Type 155+ */
> > +enum vbt_gmbus_ddi {
> > +	DDC_BUS_DDI_B = 0x1,
> > +	DDC_BUS_DDI_C,
> > +	DDC_BUS_DDI_D,
> > +	DDC_BUS_DDI_F,
> > +};
> > +
> >  /*
> >   * The child device config, aka the display device data structure, provides a
> >   * description of a port and its configuration on the platform.
> > -- 
> > 2.13.5
> 
> -- 
> Ville Syrjälä
> Intel OTC