drm/i915/rkl: Handle HTI

If HTI (also sometimes called HDPORT) is enabled at startup, it may be
using some of the PHYs and DPLLs making them unavailable for general
usage.  Let's read out the HDPORT_STATE register and avoid making use of
resources that HTI is already using.

v2:
 - Fix minor checkpatch warnings

v3:
 - Just readout HDPORT_STATE register once during init and then parse it
   later as needed.
 - Add a 'has_hti' device info flag to track whether we should readout
   HDPORT_STATE or not.  We can skip the platform/flag tests later since
   the hti_state in dev_priv will remain 0 for platforms it does not
   apply to.
 - Move PLL masking into icl_get_combo_phy_dpll() since at the moment
   RKL is the only platform that has HTI.  (Jose)

Bspec: 49189
Bspec: 53707
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200716220551.2730644-5-matthew.d.roper@intel.com
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

3 files changed, 38 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index 1ca70f9abc8d..714b2bc96f23 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -4923,6 +4923,13 @@ intel_ddi_max_lanes(struct intel_digital_port *dig_port)
 	return max_lanes;
 }
 
+static bool hti_uses_phy(struct drm_i915_private *i915, enum phy phy)
+{
+	return i915->hti_state & HDPORT_ENABLED &&
+		(i915->hti_state & HDPORT_PHY_USED_DP(phy) ||
+		 i915->hti_state & HDPORT_PHY_USED_HDMI(phy));
+}
+
 void intel_ddi_init(struct drm_i915_private *dev_priv, enum port port)
 {
 	struct intel_digital_port *dig_port;
@@ -4930,6 +4937,18 @@ void intel_ddi_init(struct drm_i915_private *dev_priv, enum port port)
 	bool init_hdmi, init_dp, init_lspcon = false;
 	enum phy phy = intel_port_to_phy(dev_priv, port);
 
+	/*
+	 * On platforms with HTI (aka HDPORT), if it's enabled at boot it may
+	 * have taken over some of the PHYs and made them unavailable to the
+	 * driver.  In that case we should skip initializing the corresponding
+	 * outputs.
+	 */
+	if (hti_uses_phy(dev_priv, phy)) {
+		drm_dbg_kms(&dev_priv->drm, "PORT %c / PHY %c reserved by HTI\n",
+			    port_name(port), phy_name(phy));
+		return;
+	}
+
 	init_hdmi = intel_bios_port_supports_dvi(dev_priv, port) ||
 		intel_bios_port_supports_hdmi(dev_priv, port);
 	init_dp = intel_bios_port_supports_dp(dev_priv, port);
diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 6cb66580ad2c..db2a5a1a9b35 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -47,6 +47,7 @@
 #include "display/intel_ddi.h"
 #include "display/intel_dp.h"
 #include "display/intel_dp_mst.h"
+#include "display/intel_dpll_mgr.h"
 #include "display/intel_dsi.h"
 #include "display/intel_dvo.h"
 #include "display/intel_gmbus.h"
@@ -17903,6 +17904,13 @@ int intel_modeset_init(struct drm_i915_private *i915)
 	if (i915->max_cdclk_freq == 0)
 		intel_update_max_cdclk(i915);
 
+	/*
+	 * If the platform has HTI, we need to find out whether it has reserved
+	 * any display resources before we create our display outputs.
+	 */
+	if (INTEL_INFO(i915)->display.has_hti)
+		i915->hti_state = intel_de_read(i915, HDPORT_STATE);
+
 	/* Just disable it once at startup */
 	intel_vga_disable(i915);
 	intel_setup_outputs(i915);
diff --git a/drivers/gpu/drm/i915/display/intel_dpll_mgr.c b/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
index 134c2ecf4c80..81ab975fe4f0 100644
--- a/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
+++ b/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
@@ -3475,6 +3475,14 @@ static void icl_update_active_dpll(struct intel_atomic_state *state,
 	icl_set_active_port_dpll(crtc_state, port_dpll_id);
 }
 
+static u32 intel_get_hti_plls(struct drm_i915_private *i915)
+{
+	if (!(i915->hti_state & HDPORT_ENABLED))
+		return 0;
+
+	return REG_FIELD_GET(HDPORT_DPLL_USED_MASK, i915->hti_state);
+}
+
 static bool icl_get_combo_phy_dpll(struct intel_atomic_state *state,
 				   struct intel_crtc *crtc,
 				   struct intel_encoder *encoder)
@@ -3518,6 +3526,9 @@ static bool icl_get_combo_phy_dpll(struct intel_atomic_state *state,
 		dpll_mask = BIT(DPLL_ID_ICL_DPLL1) | BIT(DPLL_ID_ICL_DPLL0);
 	}
 
+	/* Eliminate DPLLs from consideration if reserved by HTI */
+	dpll_mask &= ~intel_get_hti_plls(dev_priv);
+
 	port_dpll->pll = intel_find_shared_dpll(state, crtc,
 						&port_dpll->hw_state,
 						dpll_mask);