drm/i915/icl: implement icl_digital_port_connected()

Do like the other functions and check for the status bits. The "Hot
Plug Detection" page from our documentation says we can't just use the
ISR bits on the CPU side (North Display, which has the TC and TBT
modes), so use the correct register: DFLEXDPSP, TC Live State field.

v2: Rebase.
v3:
  - Simplify true/false assignment (Rodrigo).
  - Reorganize is_gen if ladder (Rodrigo).
  - Don't use the ISR for TC/TBT CPU bits.
v4:
  - Improve commit message wording (Lucas).
v5:
  - COMMIT_LOG_LONG_LINE (Checkpatch).

Cc: Animesh Manna <animesh.manna@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com> (v3).
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180725195927.12059-1-paulo.r.zanoni@intel.com

drivers/gpu/drm/i915/i915_reg.h

@@ -7254,6 +7254,7 @@ enum {
 #define  GEN11_TC3_HOTPLUG			(1 << 18)
 #define  GEN11_TC2_HOTPLUG			(1 << 17)
 #define  GEN11_TC1_HOTPLUG			(1 << 16)
+#define  GEN11_TC_HOTPLUG(tc_port)		(1 << ((tc_port) + 16))
 #define  GEN11_DE_TC_HOTPLUG_MASK		(GEN11_TC4_HOTPLUG | \
 						 GEN11_TC3_HOTPLUG | \
 						 GEN11_TC2_HOTPLUG | \
@@ -7262,6 +7263,7 @@ enum {
 #define  GEN11_TBT3_HOTPLUG			(1 << 2)
 #define  GEN11_TBT2_HOTPLUG			(1 << 1)
 #define  GEN11_TBT1_HOTPLUG			(1 << 0)
+#define  GEN11_TBT_HOTPLUG(tc_port)		(1 << (tc_port))
 #define  GEN11_DE_TBT_HOTPLUG_MASK		(GEN11_TBT4_HOTPLUG | \
 						 GEN11_TBT3_HOTPLUG | \
 						 GEN11_TBT2_HOTPLUG | \
@@ -7634,6 +7636,8 @@ enum {
 #define SDE_GMBUS_ICP			(1 << 23)
 #define SDE_DDIB_HOTPLUG_ICP		(1 << 17)
 #define SDE_DDIA_HOTPLUG_ICP		(1 << 16)
+#define SDE_TC_HOTPLUG_ICP(tc_port)	(1 << ((tc_port) + 24))
+#define SDE_DDI_HOTPLUG_ICP(port)	(1 << ((port) + 16))
 #define SDE_DDI_MASK_ICP		(SDE_DDIB_HOTPLUG_ICP |	\
 					 SDE_DDIA_HOTPLUG_ICP)
 #define SDE_TC_MASK_ICP			(SDE_TC4_HOTPLUG_ICP |	\
@@ -10698,4 +10702,8 @@ enum skl_power_gate {
 						_ICL_DSC1_RC_BUF_THRESH_1_UDW_PB, \
 						_ICL_DSC1_RC_BUF_THRESH_1_UDW_PC)
 
+#define PORT_TX_DFLEXDPSP			_MMIO(0x1638A0)
+#define   TC_LIVE_STATE_TBT(tc_port)		(1 << ((tc_port) * 8 + 6))
+#define   TC_LIVE_STATE_TC(tc_port)		(1 << ((tc_port) * 8 + 5))
+
 #endif /* _I915_REG_H_ */

drivers/gpu/drm/i915/intel_dp.c

@@ -4586,6 +4586,57 @@ static bool bxt_digital_port_connected(struct intel_encoder *encoder)
 	return I915_READ(GEN8_DE_PORT_ISR) & bit;
 }
 
+static bool icl_combo_port_connected(struct drm_i915_private *dev_priv,
+				     struct intel_digital_port *intel_dig_port)
+{
+	enum port port = intel_dig_port->base.port;
+
+	return I915_READ(SDEISR) & SDE_DDI_HOTPLUG_ICP(port);
+}
+
+static bool icl_tc_port_connected(struct drm_i915_private *dev_priv,
+				  struct intel_digital_port *intel_dig_port)
+{
+	enum port port = intel_dig_port->base.port;
+	enum tc_port tc_port = intel_port_to_tc(dev_priv, port);
+	bool is_legacy, is_typec, is_tbt;
+	u32 dpsp;
+
+	is_legacy = I915_READ(SDEISR) & SDE_TC_HOTPLUG_ICP(tc_port);
+
+	/*
+	 * The spec says we shouldn't be using the ISR bits for detecting
+	 * between TC and TBT. We should use DFLEXDPSP.
+	 */
+	dpsp = I915_READ(PORT_TX_DFLEXDPSP);
+	is_typec = dpsp & TC_LIVE_STATE_TC(tc_port);
+	is_tbt = dpsp & TC_LIVE_STATE_TBT(tc_port);
+
+	WARN_ON(is_legacy + is_typec + is_tbt > 1);
+
+	return is_legacy || is_typec || is_tbt;
+}
+
+static bool icl_digital_port_connected(struct intel_encoder *encoder)
+{
+	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
+	struct intel_digital_port *dig_port = enc_to_dig_port(&encoder->base);
+
+	switch (encoder->hpd_pin) {
+	case HPD_PORT_A:
+	case HPD_PORT_B:
+		return icl_combo_port_connected(dev_priv, dig_port);
+	case HPD_PORT_C:
+	case HPD_PORT_D:
+	case HPD_PORT_E:
+	case HPD_PORT_F:
+		return icl_tc_port_connected(dev_priv, dig_port);
+	default:
+		MISSING_CASE(encoder->hpd_pin);
+		return false;
+	}
+}
+
 /*
  * intel_digital_port_connected - is the specified port connected?
  * @encoder: intel_encoder
@@ -4613,8 +4664,10 @@ bool intel_digital_port_connected(struct intel_encoder *encoder)
 		return bdw_digital_port_connected(encoder);
 	else if (IS_GEN9_LP(dev_priv))
 		return bxt_digital_port_connected(encoder);
-	else
+	else if (IS_GEN9_BC(dev_priv) || IS_GEN10(dev_priv))
 		return spt_digital_port_connected(encoder);
+	else
+		return icl_digital_port_connected(encoder);
 }
 
 static struct edid *