* @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
*/
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;
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,
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
{
i2c_del_adapter(&aux->ddc);
}
+
+/**
+ * drm_dp_mst_is_virtual_dpcd() - Is the given port a virtual DP Peer Device
+ * @port: The port to check
+ *
+ * A single physical MST hub object can be represented in the topology
+ * by multiple branches, with virtual ports between those branches.
+ *
+ * As of DP1.4, An MST hub with internal (virtual) ports must expose
+ * certain DPCD registers over those ports. See sections 2.6.1.1.1
+ * and 2.6.1.1.2 of Display Port specification v1.4 for details.
+ *
+ * May acquire mgr->lock
+ *
+ * Returns:
+ * true if the port is a virtual DP peer device, false otherwise
+ */
+static bool drm_dp_mst_is_virtual_dpcd(struct drm_dp_mst_port *port)
+{
+ struct drm_dp_mst_port *downstream_port;
+
+ if (!port || port->dpcd_rev < DP_DPCD_REV_14)
+ return false;
+
+ /* Virtual DP Sink (Internal Display Panel) */
+ if (port->port_num >= 8)
+ return true;
+
+ /* DP-to-HDMI Protocol Converter */
+ if (port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV &&
+ !port->mcs &&
+ port->ldps)
+ return true;
+
+ /* DP-to-DP */
+ mutex_lock(&port->mgr->lock);
+ if (port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
+ port->mstb &&
+ port->mstb->num_ports == 2) {
+ list_for_each_entry(downstream_port, &port->mstb->ports, next) {
+ if (downstream_port->pdt == DP_PEER_DEVICE_SST_SINK &&
+ !downstream_port->input) {
+ mutex_unlock(&port->mgr->lock);
+ return true;
+ }
+ }
+ }
+ mutex_unlock(&port->mgr->lock);
+
+ return false;
+}
+
+/**
+ * drm_dp_mst_dsc_aux_for_port() - Find the correct aux for DSC
+ * @port: The port to check. A leaf of the MST tree with an attached display.
+ *
+ * Depending on the situation, DSC may be enabled via the endpoint aux,
+ * the immediately upstream aux, or the connector's physical aux.
+ *
+ * This is both the correct aux to read DSC_CAPABILITY and the
+ * correct aux to write DSC_ENABLED.
+ *
+ * This operation can be expensive (up to four aux reads), so
+ * the caller should cache the return.
+ *
+ * Returns:
+ * NULL if DSC cannot be enabled on this port, otherwise the aux device
+ */
+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;
+
+ if (!port)
+ return NULL;
+
+ if (port->parent->port_parent)
+ immediate_upstream_port = port->parent->port_parent;
+ else
+ immediate_upstream_port = NULL;
+
+ fec_port = immediate_upstream_port;
+ while (fec_port) {
+ /*
+ * Each physical link (i.e. not a virtual port) between the
+ * output and the primary device must support FEC
+ */
+ if (!drm_dp_mst_is_virtual_dpcd(fec_port) &&
+ !fec_port->fec_capable)
+ return NULL;
+
+ fec_port = fec_port->parent->port_parent;
+ }
+
+ /* DP-to-DP peer device */
+ if (drm_dp_mst_is_virtual_dpcd(immediate_upstream_port)) {
+ u8 upstream_dsc;
+
+ if (drm_dp_dpcd_read(&port->aux,
+ DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
+ return NULL;
+ if (drm_dp_dpcd_read(&port->aux,
+ DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
+ return NULL;
+ if (drm_dp_dpcd_read(&immediate_upstream_port->aux,
+ DP_DSC_SUPPORT, &upstream_dsc, 1) != 1)
+ return NULL;
+
+ /* Enpoint decompression with DP-to-DP peer device */
+ if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
+ (endpoint_fec & DP_FEC_CAPABLE) &&
+ (upstream_dsc & 0x2) /* DSC passthrough */)
+ return &port->aux;
+
+ /* Virtual DPCD decompression with DP-to-DP peer device */
+ return &immediate_upstream_port->aux;
+ }
+
+ /* Virtual DPCD decompression with DP-to-HDMI or Virtual DP Sink */
+ 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 -
+ * therefore the endpoint needs to be
+ * both DSC and FEC capable.
+ */
+ if (drm_dp_dpcd_read(&port->aux,
+ DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
+ return NULL;
+ if (drm_dp_dpcd_read(&port->aux,
+ DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
+ return NULL;
+ if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
+ (endpoint_fec & DP_FEC_CAPABLE))
+ return &port->aux;
+
+ return NULL;
+}
+EXPORT_SYMBOL(drm_dp_mst_dsc_aux_for_port);
projects / linux.git / blobdiff