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 <[e-mail]>
Cc: José Roberto de Souza <[e-mail]>
Signed-off-by: Matt Roper <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]
Reviewed-by: José Roberto de Souza <[e-mail]>
Signed-off-by: Rodrigo Vivi <[e-mail]>

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

···
 	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;
 	struct intel_encoder *encoder;
 	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);

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

···
 #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"
···
 
 	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);

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

···
 	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)
···
 	} else {
 		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,

drivers/gpu/drm/i915/i915_drv.h

···
 	struct intel_l3_parity l3_parity;
 
 	/*
+	 * HTI (aka HDPORT) state read during initial hw readout.  Most
+	 * platforms don't have HTI, so this will just stay 0.  Those that do
+	 * will use this later to figure out which PLLs and PHYs are unavailable
+	 * for driver usage.
+	 */
+	u32 hti_state;
+
+	/*
 	 * edram size in MB.
 	 * Cannot be determined by PCIID. You must always read a register.
 	 */

drivers/gpu/drm/i915/i915_pci.c

···
 	.cpu_transcoder_mask = BIT(TRANSCODER_A) | BIT(TRANSCODER_B) |
 		BIT(TRANSCODER_C),
 	.require_force_probe = 1,
+	.display.has_hti = 1,
 	.display.has_psr_hw_tracking = 0,
 	.platform_engine_mask =
 		BIT(RCS0) | BIT(BCS0) | BIT(VECS0) | BIT(VCS0),

drivers/gpu/drm/i915/i915_reg.h

···
 #define MBUS_BBOX_CTL_S1		_MMIO(0x45040)
 #define MBUS_BBOX_CTL_S2		_MMIO(0x45044)
 
+#define HDPORT_STATE			_MMIO(0x45050)
+#define   HDPORT_DPLL_USED_MASK		REG_GENMASK(14, 12)
+#define   HDPORT_PHY_USED_DP(phy)	REG_BIT(2 * (phy) + 2)
+#define   HDPORT_PHY_USED_HDMI(phy)	REG_BIT(2 * (phy) + 1)
+#define   HDPORT_ENABLED		REG_BIT(0)
+
 /* Make render/texture TLB fetches lower priorty than associated data
  *   fetches. This is not turned on by default
  */

drivers/gpu/drm/i915/intel_device_info.h

···
 	func(has_gmch); \
 	func(has_hdcp); \
 	func(has_hotplug); \
+	func(has_hti); \
 	func(has_ipc); \
 	func(has_modular_fia); \
 	func(has_overlay); \