drm/i915: Move the TypeC port handling code to a separate file

Move the TypeC port handling functions to a new file for clarity.

While at it:
- s/icl_tc_port_connected()/intel_tc_port_connected()/
  icl_tc_phy_disconnect(), will be unexported later.

- s/intel_dp_get_fia_supported_lane_count()/
    intel_tc_port_fia_max_lane_count()/
  It's used for HDMI legacy mode too.

- Simplify function interfaces by passing only dig_port to them.

No functional changes.

v2:
- Fix checkpatch issues: +1/-1 empty lines in intel_tc.c and add
  missing SPDX to intel_tc.h. (Jani)

Cc: Animesh Manna <animesh.manna@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: José Roberto de Souza <jose.souza@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190628143635.22066-4-imre.deak@intel.com

1 files changed, 230 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c
new file mode 100644
index 000000000000..4fa9ea695d51
--- /dev/null
+++ b/drivers/gpu/drm/i915/display/intel_tc.c
@@ -0,0 +1,230 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2019 Intel Corporation
+ */
+
+#include "intel_display.h"
+#include "i915_drv.h"
+#include "intel_tc.h"
+
+static const char *tc_type_name(enum tc_port_type type)
+{
+	static const char * const names[] = {
+		[TC_PORT_UNKNOWN] = "unknown",
+		[TC_PORT_LEGACY] = "legacy",
+		[TC_PORT_TYPEC] = "typec",
+		[TC_PORT_TBT] = "tbt",
+	};
+
+	if (WARN_ON(type >= ARRAY_SIZE(names)))
+		type = TC_PORT_UNKNOWN;
+
+	return names[type];
+}
+
+int intel_tc_port_fia_max_lane_count(struct intel_digital_port *dig_port)
+{
+	struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
+	enum tc_port tc_port = intel_port_to_tc(dev_priv, dig_port->base.port);
+	intel_wakeref_t wakeref;
+	u32 lane_info;
+
+	if (tc_port == PORT_TC_NONE || dig_port->tc_type != TC_PORT_TYPEC)
+		return 4;
+
+	lane_info = 0;
+	with_intel_display_power(dev_priv, POWER_DOMAIN_DISPLAY_CORE, wakeref)
+		lane_info = (I915_READ(PORT_TX_DFLEXDPSP) &
+			     DP_LANE_ASSIGNMENT_MASK(tc_port)) >>
+				DP_LANE_ASSIGNMENT_SHIFT(tc_port);
+
+	switch (lane_info) {
+	default:
+		MISSING_CASE(lane_info);
+	case 1:
+	case 2:
+	case 4:
+	case 8:
+		return 1;
+	case 3:
+	case 12:
+		return 2;
+	case 15:
+		return 4;
+	}
+}
+
+/*
+ * This function implements the first part of the Connect Flow described by our
+ * specification, Gen11 TypeC Programming chapter. The rest of the flow (reading
+ * lanes, EDID, etc) is done as needed in the typical places.
+ *
+ * Unlike the other ports, type-C ports are not available to use as soon as we
+ * get a hotplug. The type-C PHYs can be shared between multiple controllers:
+ * display, USB, etc. As a result, handshaking through FIA is required around
+ * connect and disconnect to cleanly transfer ownership with the controller and
+ * set the type-C power state.
+ *
+ * We could opt to only do the connect flow when we actually try to use the AUX
+ * channels or do a modeset, then immediately run the disconnect flow after
+ * usage, but there are some implications on this for a dynamic environment:
+ * things may go away or change behind our backs. So for now our driver is
+ * always trying to acquire ownership of the controller as soon as it gets an
+ * interrupt (or polls state and sees a port is connected) and only gives it
+ * back when it sees a disconnect. Implementation of a more fine-grained model
+ * will require a lot of coordination with user space and thorough testing for
+ * the extra possible cases.
+ */
+static bool icl_tc_phy_connect(struct intel_digital_port *dig_port)
+{
+	struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
+	enum tc_port tc_port = intel_port_to_tc(dev_priv, dig_port->base.port);
+	u32 val;
+
+	if (dig_port->tc_type != TC_PORT_LEGACY &&
+	    dig_port->tc_type != TC_PORT_TYPEC)
+		return true;
+
+	val = I915_READ(PORT_TX_DFLEXDPPMS);
+	if (!(val & DP_PHY_MODE_STATUS_COMPLETED(tc_port))) {
+		DRM_DEBUG_KMS("DP PHY for TC port %d not ready\n", tc_port);
+		WARN_ON(dig_port->tc_legacy_port);
+		return false;
+	}
+
+	/*
+	 * This function may be called many times in a row without an HPD event
+	 * in between, so try to avoid the write when we can.
+	 */
+	val = I915_READ(PORT_TX_DFLEXDPCSSS);
+	if (!(val & DP_PHY_MODE_STATUS_NOT_SAFE(tc_port))) {
+		val |= DP_PHY_MODE_STATUS_NOT_SAFE(tc_port);
+		I915_WRITE(PORT_TX_DFLEXDPCSSS, val);
+	}
+
+	/*
+	 * Now we have to re-check the live state, in case the port recently
+	 * became disconnected. Not necessary for legacy mode.
+	 */
+	if (dig_port->tc_type == TC_PORT_TYPEC &&
+	    !(I915_READ(PORT_TX_DFLEXDPSP) & TC_LIVE_STATE_TC(tc_port))) {
+		DRM_DEBUG_KMS("TC PHY %d sudden disconnect.\n", tc_port);
+		icl_tc_phy_disconnect(dig_port);
+		return false;
+	}
+
+	return true;
+}
+
+/*
+ * See the comment at the connect function. This implements the Disconnect
+ * Flow.
+ */
+void icl_tc_phy_disconnect(struct intel_digital_port *dig_port)
+{
+	struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
+	enum tc_port tc_port = intel_port_to_tc(dev_priv, dig_port->base.port);
+
+	if (dig_port->tc_type == TC_PORT_UNKNOWN)
+		return;
+
+	/*
+	 * TBT disconnection flow is read the live status, what was done in
+	 * caller.
+	 */
+	if (dig_port->tc_type == TC_PORT_TYPEC ||
+	    dig_port->tc_type == TC_PORT_LEGACY) {
+		u32 val;
+
+		val = I915_READ(PORT_TX_DFLEXDPCSSS);
+		val &= ~DP_PHY_MODE_STATUS_NOT_SAFE(tc_port);
+		I915_WRITE(PORT_TX_DFLEXDPCSSS, val);
+	}
+
+	DRM_DEBUG_KMS("Port %c TC type %s disconnected\n",
+		      port_name(dig_port->base.port),
+		      tc_type_name(dig_port->tc_type));
+
+	dig_port->tc_type = TC_PORT_UNKNOWN;
+}
+
+static void icl_update_tc_port_type(struct drm_i915_private *dev_priv,
+				    struct intel_digital_port *intel_dig_port,
+				    bool is_legacy, bool is_typec, bool is_tbt)
+{
+	enum port port = intel_dig_port->base.port;
+	enum tc_port_type old_type = intel_dig_port->tc_type;
+
+	WARN_ON(is_legacy + is_typec + is_tbt != 1);
+
+	if (is_legacy)
+		intel_dig_port->tc_type = TC_PORT_LEGACY;
+	else if (is_typec)
+		intel_dig_port->tc_type = TC_PORT_TYPEC;
+	else if (is_tbt)
+		intel_dig_port->tc_type = TC_PORT_TBT;
+	else
+		return;
+
+	/* Types are not supposed to be changed at runtime. */
+	WARN_ON(old_type != TC_PORT_UNKNOWN &&
+		old_type != intel_dig_port->tc_type);
+
+	if (old_type != intel_dig_port->tc_type)
+		DRM_DEBUG_KMS("Port %c has TC type %s\n", port_name(port),
+			      tc_type_name(intel_dig_port->tc_type));
+}
+
+/*
+ * The type-C ports are different because even when they are connected, they may
+ * not be available/usable by the graphics driver: see the comment on
+ * icl_tc_phy_connect(). So in our driver instead of adding the additional
+ * concept of "usable" and make everything check for "connected and usable" we
+ * define a port as "connected" when it is not only connected, but also when it
+ * is usable by the rest of the driver. That maintains the old assumption that
+ * connected ports are usable, and avoids exposing to the users objects they
+ * can't really use.
+ */
+bool intel_tc_port_connected(struct intel_digital_port *dig_port)
+{
+	struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
+	enum port port = 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;
+
+	/*
+	 * Complain if we got a legacy port HPD, but VBT didn't mark the port as
+	 * legacy. Treat the port as legacy from now on.
+	 */
+	if (!dig_port->tc_legacy_port &&
+	    I915_READ(SDEISR) & SDE_TC_HOTPLUG_ICP(tc_port)) {
+		DRM_ERROR("VBT incorrectly claims port %c is not TypeC legacy\n",
+			  port_name(port));
+		dig_port->tc_legacy_port = true;
+	}
+	is_legacy = dig_port->tc_legacy_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);
+
+	if (!is_legacy && !is_typec && !is_tbt) {
+		icl_tc_phy_disconnect(dig_port);
+
+		return false;
+	}
+
+	icl_update_tc_port_type(dev_priv, dig_port, is_legacy, is_typec,
+				is_tbt);
+
+	if (!icl_tc_phy_connect(dig_port))
+		return false;
+
+	return true;
+}
+