drm/i915/gen11: Start distinguishing 'phy' from 'port'

Our past DDI-based Intel platforms have had a fixed DDI<->PHY mapping.
Because of this, both the bspec documentation and our i915 code has used
the term "port" when talking about either DDI's or PHY's; it was always
easy to tell what terms like "Port A" were referring to from the
context.

Unfortunately this is starting to break down now that EHL allows PHY-A
to be driven by either DDI-A or DDI-D.  Is a setup with DDI-D driving
PHY-A considered "Port A" or "Port D?"  The answer depends on which
register we're working with, and even the bspec doesn't do a great job
of clarifying this.

Let's try to be more explicit about whether we're talking about the DDI
or the PHY on gen11+ by using 'port' to refer to the DDI and creating a
new 'enum phy' namespace to refer to the PHY in use.

This patch just adds the new PHY namespace, new phy-based versions of
intel_port_is_*(), and a helper to convert a port to a PHY.
Transitioning various areas of the code over to using the PHY namespace
will be done in subsequent patches to make review easier.  We'll remove
the intel_port_is_*() functions at the end of the series when we
transition all callers over to using the PHY-based versions.

v2:
 - Convert a few more 'port' uses to 'phy.' (Sparse)

v3:
 - Switch DDI_CLK_SEL() back to 'port.' (Jose)
 - Add a code comment clarifying why DPCLKA_CFGCR0_ICL needs to use PHY
   for its bit definitions, even though the register description is
   given in terms of DDI.
 - To avoid confusion, switch CNL's DPCLKA_CFGCR0 defines back to using
   port and create separate ICL+ definitions that work in terms of PHY.

v4:
 - Rebase and resolve conflicts with Imre's TC series.
 - This patch now just adds the namespace and a few convenience
   functions; the important changes are now split out into separate
   patches to make review easier.

Suggested-by: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: José Roberto de Souza <jose.souza@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190709183934.445-2-matthew.d.roper@intel.com

drivers/gpu/drm/i915/display/intel_display.c

@@ -6685,6 +6685,20 @@ bool intel_port_is_combophy(struct drm_i915_private *dev_priv, enum port port)
 	return false;
 }
 
+bool intel_phy_is_combo(struct drm_i915_private *dev_priv, enum phy phy)
+{
+	if (phy == PHY_NONE)
+		return false;
+
+	if (IS_ELKHARTLAKE(dev_priv))
+		return phy <= PHY_C;
+
+	if (INTEL_GEN(dev_priv) >= 11)
+		return phy <= PHY_B;
+
+	return false;
+}
+
 bool intel_port_is_tc(struct drm_i915_private *dev_priv, enum port port)
 {
 	if (INTEL_GEN(dev_priv) >= 11 && !IS_ELKHARTLAKE(dev_priv))
@@ -6693,9 +6707,25 @@ bool intel_port_is_tc(struct drm_i915_private *dev_priv, enum port port)
 	return false;
 }
 
+bool intel_phy_is_tc(struct drm_i915_private *dev_priv, enum phy phy)
+{
+	if (INTEL_GEN(dev_priv) >= 11 && !IS_ELKHARTLAKE(dev_priv))
+		return phy >= PHY_C && phy <= PHY_F;
+
+	return false;
+}
+
+enum phy intel_port_to_phy(struct drm_i915_private *i915, enum port port)
+{
+	if (IS_ELKHARTLAKE(i915) && port == PORT_D)
+		return PHY_A;
+
+	return (enum phy)port;
+}
+
 enum tc_port intel_port_to_tc(struct drm_i915_private *dev_priv, enum port port)
 {
-	if (!intel_port_is_tc(dev_priv, port))
+	if (!intel_phy_is_tc(dev_priv, intel_port_to_phy(dev_priv, port)))
 		return PORT_TC_NONE;
 
 	return port - PORT_C;

drivers/gpu/drm/i915/display/intel_display.h

@@ -228,6 +228,21 @@ struct intel_link_m_n {
 	u32 link_n;
 };
 
+enum phy {
+	PHY_NONE = -1,
+
+	PHY_A = 0,
+	PHY_B,
+	PHY_C,
+	PHY_D,
+	PHY_E,
+	PHY_F,
+
+	I915_MAX_PHYS
+};
+
+#define phy_name(a) ((a) + 'A')
+
 #define for_each_pipe(__dev_priv, __p) \
 	for ((__p) = 0; (__p) < INTEL_INFO(__dev_priv)->num_pipes; (__p)++)
 
@@ -356,5 +371,6 @@ void lpt_disable_clkout_dp(struct drm_i915_private *dev_priv);
 u32 intel_plane_fb_max_stride(struct drm_i915_private *dev_priv,
 			      u32 pixel_format, u64 modifier);
 bool intel_plane_can_remap(const struct intel_plane_state *plane_state);
+enum phy intel_port_to_phy(struct drm_i915_private *i915, enum port port);
 
 #endif

drivers/gpu/drm/i915/intel_drv.h

@@ -1493,7 +1493,9 @@ void intel_encoder_destroy(struct drm_encoder *encoder);
 struct drm_display_mode *
 intel_encoder_current_mode(struct intel_encoder *encoder);
 bool intel_port_is_combophy(struct drm_i915_private *dev_priv, enum port port);
+bool intel_phy_is_combo(struct drm_i915_private *dev_priv, enum phy phy);
 bool intel_port_is_tc(struct drm_i915_private *dev_priv, enum port port);
+bool intel_phy_is_tc(struct drm_i915_private *dev_priv, enum phy phy);
 enum tc_port intel_port_to_tc(struct drm_i915_private *dev_priv,
 			      enum port port);
 int intel_get_pipe_from_crtc_id_ioctl(struct drm_device *dev, void *data,