drm/dp_mst: Add DSC enablement helpers to DRM

[linux.git] / drivers / gpu / drm / drm_dp_mst_topology.c

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 2b20caa4b7e3aaac9ced33b252f0d8c036a381c7..9f7e714c518256ce6cd16a1429af7017b1f6e427 100644 (file)
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -4093,6 +4093,7 @@ static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
  * @mgr: MST topology manager for the port
  * @port: port to find vcpi slots for
  * @pbn: bandwidth required for the mode in PBN
+ * @pbn_div: divider for DSC mode that takes FEC into account
  *
  * Allocates VCPI slots to @port, replacing any previous VCPI allocations it
  * may have had. Any atomic drivers which support MST must call this function
@@ -4119,7 +4120,8 @@ static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
  */
 int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
                                  struct drm_dp_mst_topology_mgr *mgr,
-                                 struct drm_dp_mst_port *port, int pbn)
+                                 struct drm_dp_mst_port *port, int pbn,
+                                 int pbn_div)
 {
        struct drm_dp_mst_topology_state *topology_state;
        struct drm_dp_vcpi_allocation *pos, *vcpi = NULL;
@@ -4152,7 +4154,10 @@ int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
        if (!vcpi)
                prev_slots = 0;
 
-       req_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
+       if (pbn_div <= 0)
+               pbn_div = mgr->pbn_div;
+
+       req_slots = DIV_ROUND_UP(pbn, pbn_div);
 
        DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] VCPI %d -> %d\n",
                         port->connector->base.id, port->connector->name,
@@ -4784,6 +4789,67 @@ drm_dp_mst_atomic_check_topology_state(struct drm_dp_mst_topology_mgr *mgr,
        return 0;
 }
 
+/**
+ * drm_dp_mst_atomic_enable_dsc - Set DSC Enable Flag to On/Off
+ * @state: Pointer to the new drm_atomic_state
+ * @port: Pointer to the affected MST Port
+ * @pbn: Newly recalculated bw required for link with DSC enabled
+ * @pbn_div: Divider to calculate correct number of pbn per slot
+ * @enable: Boolean flag to enable or disable DSC on the port
+ *
+ * This function enables DSC on the given Port
+ * by recalculating its vcpi from pbn provided
+ * and sets dsc_enable flag to keep track of which
+ * ports have DSC enabled
+ *
+ */
+int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state,
+                                struct drm_dp_mst_port *port,
+                                int pbn, int pbn_div,
+                                bool enable)
+{
+       struct drm_dp_mst_topology_state *mst_state;
+       struct drm_dp_vcpi_allocation *pos;
+       bool found = false;
+       int vcpi = 0;
+
+       mst_state = drm_atomic_get_mst_topology_state(state, port->mgr);
+
+       if (IS_ERR(mst_state))
+               return PTR_ERR(mst_state);
+
+       list_for_each_entry(pos, &mst_state->vcpis, next) {
+               if (pos->port == port) {
+                       found = true;
+                       break;
+               }
+       }
+
+       if (!found) {
+               DRM_DEBUG_ATOMIC("[MST PORT:%p] Couldn't find VCPI allocation in mst state %p\n",
+                                port, mst_state);
+               return -EINVAL;
+       }
+
+       if (pos->dsc_enabled == enable) {
+               DRM_DEBUG_ATOMIC("[MST PORT:%p] DSC flag is already set to %d, returning %d VCPI slots\n",
+                                port, enable, pos->vcpi);
+               vcpi = pos->vcpi;
+       }
+
+       if (enable) {
+               vcpi = drm_dp_atomic_find_vcpi_slots(state, port->mgr, port, pbn, pbn_div);
+               DRM_DEBUG_ATOMIC("[MST PORT:%p] Enabling DSC flag, reallocating %d VCPI slots on the port\n",
+                                port, vcpi);
+               if (vcpi < 0)
+                       return -EINVAL;
+       }
+
+       pos->dsc_enabled = enable;
+
+       return vcpi;
+}
+EXPORT_SYMBOL(drm_dp_mst_atomic_enable_dsc);
 /**
  * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an
  * atomic update is valid
@@ -5148,6 +5214,7 @@ struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port)
 {
        struct drm_dp_mst_port *immediate_upstream_port;
        struct drm_dp_mst_port *fec_port;
+       struct drm_dp_desc desc = { 0 };
        u8 endpoint_fec;
        u8 endpoint_dsc;
 
@@ -5200,6 +5267,32 @@ struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port)
        if (drm_dp_mst_is_virtual_dpcd(port))
                return &port->aux;
 
+       /*
+        * Synaptics quirk
+        * Applies to ports for which:
+        * - Physical aux has Synaptics OUI
+        * - DPv1.4 or higher
+        * - Port is on primary branch device
+        * - Not a VGA adapter (DP_DWN_STRM_PORT_TYPE_ANALOG)
+        */
+       if (drm_dp_read_desc(port->mgr->aux, &desc, true))
+               return NULL;
+
+       if (drm_dp_has_quirk(&desc, DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) &&
+           port->mgr->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14 &&
+           port->parent == port->mgr->mst_primary) {
+               u8 downstreamport;
+
+               if (drm_dp_dpcd_read(&port->aux, DP_DOWNSTREAMPORT_PRESENT,
+                                    &downstreamport, 1) < 0)
+                       return NULL;
+
+               if ((downstreamport & DP_DWN_STRM_PORT_PRESENT) &&
+                  ((downstreamport & DP_DWN_STRM_PORT_TYPE_MASK)
+                    != DP_DWN_STRM_PORT_TYPE_ANALOG))
+                       return port->mgr->aux;
+       }
+
        /*
         * The check below verifies if the MST sink
         * connected to the GPU is capable of DSC -