drm/i915/psr: Remove open-coded PSR AUX transactions for SKL+

HSW and BDW have SRD_AUX_{CTL, STATUS} registers that the driver needs to
setup for the HW to use whenever exiting PSR. SKL+ hardware use hardcoded
values for the same and do not need any registers to be setup. So, use
drm_dp_dpcd_writeb() for a one-time write during PSR enable and setup the
PSR aux registers on HSW and BDW for later use by HW.

We also end up writing to reserved bits in SRD_AUX_CTL by reusing
intel_dp->get_aux_send_ctl() for HSW and BDW, fix this.

Since the AUX register setup is source side programming, move the call
to enable_source() from enable_sink().

Cc: José Roberto de Souza <jose.souza@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: Jose Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180313034646.3721-2-dhinakaran.pandiyan@intel.com

drivers/gpu/drm/i915/i915_reg.h

@@ -3846,6 +3846,12 @@ enum {
 #define   EDP_PSR_IDLE_FRAME_SHIFT		0
 
 #define EDP_PSR_AUX_CTL				_MMIO(dev_priv->psr_mmio_base + 0x10)
+#define   EDP_PSR_AUX_CTL_TIME_OUT_MASK		(3 << 26)
+#define   EDP_PSR_AUX_CTL_MESSAGE_SIZE_MASK	(0x1f << 20)
+#define   EDP_PSR_AUX_CTL_PRECHARGE_2US_MASK	(0xf << 16)
+#define   EDP_PSR_AUX_CTL_ERROR_INTERRUPT	(1 << 11)
+#define   EDP_PSR_AUX_CTL_BIT_CLOCK_2X_MASK	(0x7ff)
+
 #define EDP_PSR_AUX_DATA(i)			_MMIO(dev_priv->psr_mmio_base + 0x14 + (i) * 4) /* 5 registers */
 
 #define EDP_PSR_STATUS				_MMIO(dev_priv->psr_mmio_base + 0x40)

drivers/gpu/drm/i915/intel_psr.c

@@ -228,31 +228,12 @@ static void vlv_psr_enable_sink(struct intel_dp *intel_dp)
 			   DP_PSR_ENABLE | DP_PSR_MAIN_LINK_ACTIVE);
 }
 
-static i915_reg_t psr_aux_ctl_reg(struct drm_i915_private *dev_priv,
-				       enum port port)
-{
-	if (INTEL_GEN(dev_priv) >= 9)
-		return DP_AUX_CH_CTL(port);
-	else
-		return EDP_PSR_AUX_CTL;
-}
-
-static i915_reg_t psr_aux_data_reg(struct drm_i915_private *dev_priv,
-					enum port port, int index)
-{
-	if (INTEL_GEN(dev_priv) >= 9)
-		return DP_AUX_CH_DATA(port, index);
-	else
-		return EDP_PSR_AUX_DATA(index);
-}
-
 static void hsw_psr_setup_aux(struct intel_dp *intel_dp)
 {
 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
-	struct drm_device *dev = dig_port->base.base.dev;
-	struct drm_i915_private *dev_priv = to_i915(dev);
-	uint32_t aux_clock_divider;
-	i915_reg_t aux_ctl_reg;
+	struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
+	u32 aux_clock_divider, aux_ctl;
+	int i;
 	static const uint8_t aux_msg[] = {
 		[0] = DP_AUX_NATIVE_WRITE << 4,
 		[1] = DP_SET_POWER >> 8,
@@ -260,23 +241,25 @@ static void hsw_psr_setup_aux(struct intel_dp *intel_dp)
 		[3] = 1 - 1,
 		[4] = DP_SET_POWER_D0,
 	};
-	enum port port = dig_port->base.port;
-	u32 aux_ctl;
-	int i;
+	u32 psr_aux_mask = EDP_PSR_AUX_CTL_TIME_OUT_MASK |
+			   EDP_PSR_AUX_CTL_MESSAGE_SIZE_MASK |
+			   EDP_PSR_AUX_CTL_PRECHARGE_2US_MASK |
+			   EDP_PSR_AUX_CTL_BIT_CLOCK_2X_MASK;
 
 	BUILD_BUG_ON(sizeof(aux_msg) > 20);
-
-	aux_clock_divider = intel_dp->get_aux_clock_divider(intel_dp, 0);
-	aux_ctl_reg = psr_aux_ctl_reg(dev_priv, port);
-
-	/* Setup AUX registers */
 	for (i = 0; i < sizeof(aux_msg); i += 4)
-		I915_WRITE(psr_aux_data_reg(dev_priv, port, i >> 2),
+		I915_WRITE(EDP_PSR_AUX_DATA(i >> 2),
 			   intel_dp_pack_aux(&aux_msg[i], sizeof(aux_msg) - i));
 
+	aux_clock_divider = intel_dp->get_aux_clock_divider(intel_dp, 0);
+
+	/* Start with bits set for DDI_AUX_CTL register */
 	aux_ctl = intel_dp->get_aux_send_ctl(intel_dp, 0, sizeof(aux_msg),
 					     aux_clock_divider);
-	I915_WRITE(aux_ctl_reg, aux_ctl);
+
+	/* Select only valid bits for SRD_AUX_CTL */
+	aux_ctl &= psr_aux_mask;
+	I915_WRITE(EDP_PSR_AUX_CTL, aux_ctl);
 }
 
 static void hsw_psr_enable_sink(struct intel_dp *intel_dp)
@@ -303,7 +286,7 @@ static void hsw_psr_enable_sink(struct intel_dp *intel_dp)
 		drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_EN_CFG,
 				   DP_PSR_ENABLE);
 
-	hsw_psr_setup_aux(intel_dp);
+	drm_dp_dpcd_writeb(&intel_dp->aux, DP_SET_POWER, DP_SET_POWER_D0);
 }
 
 static void vlv_psr_enable_source(struct intel_dp *intel_dp,
@@ -599,6 +582,12 @@ static void hsw_psr_enable_source(struct intel_dp *intel_dp,
 
 	psr_aux_io_power_get(intel_dp);
 
+	/* Only HSW and BDW have PSR AUX registers that need to be setup. SKL+
+	 * use hardcoded values PSR AUX transactions
+	 */
+	if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))
+		hsw_psr_setup_aux(intel_dp);
+
 	if (dev_priv->psr.psr2_support) {
 		chicken = PSR2_VSC_ENABLE_PROG_HEADER;
 		if (dev_priv->psr.y_cord_support)