drm/i915: Remove the magic AUX_CTL is at DP + foo tricks

Currently we determine the location of the AUX registers in a confusing
way. First we assume the PCH registers are used always, but then we
override it for everything but HSW/BDW to use DP+0x10. Very confusing.

Let's just make it straightforward and simply add a few functions to
pick the right AUX_CTL based on the DP port.

To deal with VLV/CHV we'll include the display_mmio_offset into the
AUX register defines.

v2: Reorder patches (Chris)
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v1)
Link: http://patchwork.freedesktop.org/patch/msgid/1447266856-30249-5-git-send-email-ville.syrjala@linux.intel.com

drivers/gpu/drm/i915/i915_reg.h

@@ -4228,33 +4228,33 @@ enum skl_disp_power_wells {
  * is 20 bytes in each direction, hence the 5 fixed
  * data registers
  */
-#define _DPA_AUX_CH_CTL			0x64010
-#define _DPA_AUX_CH_DATA1		0x64014
-#define _DPA_AUX_CH_DATA2		0x64018
-#define _DPA_AUX_CH_DATA3		0x6401c
-#define _DPA_AUX_CH_DATA4		0x64020
-#define _DPA_AUX_CH_DATA5		0x64024
-
-#define _DPB_AUX_CH_CTL			0x64110
-#define _DPB_AUX_CH_DATA1		0x64114
-#define _DPB_AUX_CH_DATA2		0x64118
-#define _DPB_AUX_CH_DATA3		0x6411c
-#define _DPB_AUX_CH_DATA4		0x64120
-#define _DPB_AUX_CH_DATA5		0x64124
-
-#define _DPC_AUX_CH_CTL			0x64210
-#define _DPC_AUX_CH_DATA1		0x64214
-#define _DPC_AUX_CH_DATA2		0x64218
-#define _DPC_AUX_CH_DATA3		0x6421c
-#define _DPC_AUX_CH_DATA4		0x64220
-#define _DPC_AUX_CH_DATA5		0x64224
-
-#define _DPD_AUX_CH_CTL			0x64310
-#define _DPD_AUX_CH_DATA1		0x64314
-#define _DPD_AUX_CH_DATA2		0x64318
-#define _DPD_AUX_CH_DATA3		0x6431c
-#define _DPD_AUX_CH_DATA4		0x64320
-#define _DPD_AUX_CH_DATA5		0x64324
+#define _DPA_AUX_CH_CTL		(dev_priv->info.display_mmio_offset + 0x64010)
+#define _DPA_AUX_CH_DATA1	(dev_priv->info.display_mmio_offset + 0x64014)
+#define _DPA_AUX_CH_DATA2	(dev_priv->info.display_mmio_offset + 0x64018)
+#define _DPA_AUX_CH_DATA3	(dev_priv->info.display_mmio_offset + 0x6401c)
+#define _DPA_AUX_CH_DATA4	(dev_priv->info.display_mmio_offset + 0x64020)
+#define _DPA_AUX_CH_DATA5	(dev_priv->info.display_mmio_offset + 0x64024)
+
+#define _DPB_AUX_CH_CTL		(dev_priv->info.display_mmio_offset + 0x64110)
+#define _DPB_AUX_CH_DATA1	(dev_priv->info.display_mmio_offset + 0x64114)
+#define _DPB_AUX_CH_DATA2	(dev_priv->info.display_mmio_offset + 0x64118)
+#define _DPB_AUX_CH_DATA3	(dev_priv->info.display_mmio_offset + 0x6411c)
+#define _DPB_AUX_CH_DATA4	(dev_priv->info.display_mmio_offset + 0x64120)
+#define _DPB_AUX_CH_DATA5	(dev_priv->info.display_mmio_offset + 0x64124)
+
+#define _DPC_AUX_CH_CTL		(dev_priv->info.display_mmio_offset + 0x64210)
+#define _DPC_AUX_CH_DATA1	(dev_priv->info.display_mmio_offset + 0x64214)
+#define _DPC_AUX_CH_DATA2	(dev_priv->info.display_mmio_offset + 0x64218)
+#define _DPC_AUX_CH_DATA3	(dev_priv->info.display_mmio_offset + 0x6421c)
+#define _DPC_AUX_CH_DATA4	(dev_priv->info.display_mmio_offset + 0x64220)
+#define _DPC_AUX_CH_DATA5	(dev_priv->info.display_mmio_offset + 0x64224)
+
+#define _DPD_AUX_CH_CTL		(dev_priv->info.display_mmio_offset + 0x64310)
+#define _DPD_AUX_CH_DATA1	(dev_priv->info.display_mmio_offset + 0x64314)
+#define _DPD_AUX_CH_DATA2	(dev_priv->info.display_mmio_offset + 0x64318)
+#define _DPD_AUX_CH_DATA3	(dev_priv->info.display_mmio_offset + 0x6431c)
+#define _DPD_AUX_CH_DATA4	(dev_priv->info.display_mmio_offset + 0x64320)
+#define _DPD_AUX_CH_DATA5	(dev_priv->info.display_mmio_offset + 0x64324)
 
 #define DP_AUX_CH_CTL(port)	_PORT(port, _DPA_AUX_CH_CTL, _DPB_AUX_CH_CTL)
 #define DP_AUX_CH_DATA(port, i)	(_PORT(port, _DPA_AUX_CH_DATA1, _DPB_AUX_CH_DATA1) + (i) * 4) /* 5 registers */

drivers/gpu/drm/i915/intel_dp.c

@@ -1008,71 +1008,100 @@ intel_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
 	return ret;
 }
 
-static void
-intel_dp_aux_fini(struct intel_dp *intel_dp)
+static uint32_t g4x_aux_ctl_reg(struct drm_i915_private *dev_priv,
+				enum port port)
 {
-	drm_dp_aux_unregister(&intel_dp->aux);
-	kfree(intel_dp->aux.name);
+	switch (port) {
+	case PORT_B:
+	case PORT_C:
+	case PORT_D:
+		return DP_AUX_CH_CTL(port);
+	default:
+		MISSING_CASE(port);
+		return DP_AUX_CH_CTL(PORT_B);
+	}
 }
 
-static int
-intel_dp_aux_init(struct intel_dp *intel_dp, struct intel_connector *connector)
+static uint32_t ilk_aux_ctl_reg(struct drm_i915_private *dev_priv,
+				enum port port)
 {
-	struct drm_device *dev = intel_dp_to_dev(intel_dp);
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
-	enum port port = intel_dig_port->port;
-	struct ddi_vbt_port_info *info = &dev_priv->vbt.ddi_port_info[port];
-	uint32_t porte_aux_ctl_reg = DP_AUX_CH_CTL(PORT_A);
-	int ret;
+	switch (port) {
+	case PORT_A:
+		return DP_AUX_CH_CTL(port);
+	case PORT_B:
+	case PORT_C:
+	case PORT_D:
+		return PCH_DP_AUX_CH_CTL(port);
+	default:
+		MISSING_CASE(port);
+		return DP_AUX_CH_CTL(PORT_A);
+	}
+}
 
-	/* On SKL we don't have Aux for port E so we rely on VBT to set
-	 * a proper alternate aux channel.
+/*
+ * On SKL we don't have Aux for port E so we rely
+ * on VBT to set a proper alternate aux channel.
  */
-	if ((IS_SKYLAKE(dev) || IS_KABYLAKE(dev)) && port == PORT_E) {
+static enum port skl_porte_aux_port(struct drm_i915_private *dev_priv)
+{
+	const struct ddi_vbt_port_info *info =
+		&dev_priv->vbt.ddi_port_info[PORT_E];
+
 	switch (info->alternate_aux_channel) {
+	case DP_AUX_A:
+		return PORT_A;
 	case DP_AUX_B:
-			porte_aux_ctl_reg = DP_AUX_CH_CTL(PORT_B);
-			break;
+		return PORT_B;
 	case DP_AUX_C:
-			porte_aux_ctl_reg = DP_AUX_CH_CTL(PORT_C);
-			break;
+		return PORT_C;
 	case DP_AUX_D:
-			porte_aux_ctl_reg = DP_AUX_CH_CTL(PORT_D);
-			break;
-		case DP_AUX_A:
+		return PORT_D;
 	default:
-			porte_aux_ctl_reg = DP_AUX_CH_CTL(PORT_A);
-		}
+		MISSING_CASE(info->alternate_aux_channel);
+		return PORT_A;
 	}
+}
+
+static uint32_t skl_aux_ctl_reg(struct drm_i915_private *dev_priv,
+				enum port port)
+{
+	if (port == PORT_E)
+		port = skl_porte_aux_port(dev_priv);
 
 	switch (port) {
 	case PORT_A:
-		intel_dp->aux_ch_ctl_reg = DP_AUX_CH_CTL(port);
-		break;
 	case PORT_B:
 	case PORT_C:
 	case PORT_D:
-		intel_dp->aux_ch_ctl_reg = PCH_DP_AUX_CH_CTL(port);
-		break;
-	case PORT_E:
-		intel_dp->aux_ch_ctl_reg = porte_aux_ctl_reg;
-		break;
+		return DP_AUX_CH_CTL(port);
 	default:
-		BUG();
+		MISSING_CASE(port);
+		return DP_AUX_CH_CTL(PORT_A);
 	}
+}
 
-	/*
-	 * The AUX_CTL register is usually DP_CTL + 0x10.
-	 *
-	 * On Haswell and Broadwell though:
-	 *   - Both port A DDI_BUF_CTL and DDI_AUX_CTL are on the CPU
-	 *   - Port B/C/D AUX channels are on the PCH, DDI_BUF_CTL on the CPU
-	 *
-	 * Skylake moves AUX_CTL back next to DDI_BUF_CTL, on the CPU.
-	 */
-	if (!IS_HASWELL(dev) && !IS_BROADWELL(dev) && port != PORT_E)
-		intel_dp->aux_ch_ctl_reg = intel_dp->output_reg + 0x10;
+static void
+intel_dp_aux_fini(struct intel_dp *intel_dp)
+{
+	drm_dp_aux_unregister(&intel_dp->aux);
+	kfree(intel_dp->aux.name);
+}
+
+static int
+intel_dp_aux_init(struct intel_dp *intel_dp, struct intel_connector *connector)
+{
+	struct drm_device *dev = intel_dp_to_dev(intel_dp);
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
+	enum port port = intel_dig_port->port;
+	int ret;
+
+	if (INTEL_INFO(dev_priv)->gen >= 9)
+		intel_dp->aux_ch_ctl_reg = skl_aux_ctl_reg(dev_priv, port);
+	else if (HAS_PCH_SPLIT(dev_priv))
+		intel_dp->aux_ch_ctl_reg = ilk_aux_ctl_reg(dev_priv, port);
+	else
+		intel_dp->aux_ch_ctl_reg = g4x_aux_ctl_reg(dev_priv, port);
 
 	intel_dp->aux.name = kasprintf(GFP_KERNEL, "DPDDC-%c", port_name(port));
 	if (!intel_dp->aux.name)