memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
idx += req->u.i2c_read.transactions[i].num_bytes;
- buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 5;
+ buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 4;
buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
idx++;
}
{
int idx = 1;
repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
+ repmsg->u.path_resources.fec_capable = raw->msg[idx] & 0x1;
idx++;
if (idx > raw->curlen)
goto fail_len;
txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
mstb->tx_slots[txmsg->seqno] = NULL;
}
+ mgr->is_waiting_for_dwn_reply = false;
+
}
out:
if (unlikely(ret == -EIO) && drm_debug_enabled(DRM_UT_DP)) {
}
mutex_unlock(&mgr->qlock);
+ drm_dp_mst_kick_tx(mgr);
return ret;
}
return parent_lct + 1;
}
-static int drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt)
+static bool drm_dp_mst_is_dp_mst_end_device(u8 pdt, bool mcs)
+{
+ switch (pdt) {
+ case DP_PEER_DEVICE_DP_LEGACY_CONV:
+ case DP_PEER_DEVICE_SST_SINK:
+ return true;
+ case DP_PEER_DEVICE_MST_BRANCHING:
+ /* For sst branch device */
+ if (!mcs)
+ return true;
+
+ return false;
+ }
+ return true;
+}
+
+static int
+drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt,
+ bool new_mcs)
{
struct drm_dp_mst_topology_mgr *mgr = port->mgr;
struct drm_dp_mst_branch *mstb;
u8 rad[8], lct;
int ret = 0;
- if (port->pdt == new_pdt)
+ if (port->pdt == new_pdt && port->mcs == new_mcs)
return 0;
/* Teardown the old pdt, if there is one */
- switch (port->pdt) {
- case DP_PEER_DEVICE_DP_LEGACY_CONV:
- case DP_PEER_DEVICE_SST_SINK:
- /*
- * If the new PDT would also have an i2c bus, don't bother
- * with reregistering it
- */
- if (new_pdt == DP_PEER_DEVICE_DP_LEGACY_CONV ||
- new_pdt == DP_PEER_DEVICE_SST_SINK) {
- port->pdt = new_pdt;
- return 0;
- }
+ if (port->pdt != DP_PEER_DEVICE_NONE) {
+ if (drm_dp_mst_is_dp_mst_end_device(port->pdt, port->mcs)) {
+ /*
+ * If the new PDT would also have an i2c bus,
+ * don't bother with reregistering it
+ */
+ if (new_pdt != DP_PEER_DEVICE_NONE &&
+ drm_dp_mst_is_dp_mst_end_device(new_pdt, new_mcs)) {
+ port->pdt = new_pdt;
+ port->mcs = new_mcs;
+ return 0;
+ }
- /* remove i2c over sideband */
- drm_dp_mst_unregister_i2c_bus(&port->aux);
- break;
- case DP_PEER_DEVICE_MST_BRANCHING:
- mutex_lock(&mgr->lock);
- drm_dp_mst_topology_put_mstb(port->mstb);
- port->mstb = NULL;
- mutex_unlock(&mgr->lock);
- break;
+ /* remove i2c over sideband */
+ drm_dp_mst_unregister_i2c_bus(&port->aux);
+ } else {
+ mutex_lock(&mgr->lock);
+ drm_dp_mst_topology_put_mstb(port->mstb);
+ port->mstb = NULL;
+ mutex_unlock(&mgr->lock);
+ }
}
port->pdt = new_pdt;
- switch (port->pdt) {
- case DP_PEER_DEVICE_DP_LEGACY_CONV:
- case DP_PEER_DEVICE_SST_SINK:
- /* add i2c over sideband */
- ret = drm_dp_mst_register_i2c_bus(&port->aux);
- break;
+ port->mcs = new_mcs;
- case DP_PEER_DEVICE_MST_BRANCHING:
- lct = drm_dp_calculate_rad(port, rad);
- mstb = drm_dp_add_mst_branch_device(lct, rad);
- if (!mstb) {
- ret = -ENOMEM;
- DRM_ERROR("Failed to create MSTB for port %p", port);
- goto out;
- }
+ if (port->pdt != DP_PEER_DEVICE_NONE) {
+ if (drm_dp_mst_is_dp_mst_end_device(port->pdt, port->mcs)) {
+ /* add i2c over sideband */
+ ret = drm_dp_mst_register_i2c_bus(&port->aux);
+ } else {
+ lct = drm_dp_calculate_rad(port, rad);
+ mstb = drm_dp_add_mst_branch_device(lct, rad);
+ if (!mstb) {
+ ret = -ENOMEM;
+ DRM_ERROR("Failed to create MSTB for port %p",
+ port);
+ goto out;
+ }
- mutex_lock(&mgr->lock);
- port->mstb = mstb;
- mstb->mgr = port->mgr;
- mstb->port_parent = port;
+ mutex_lock(&mgr->lock);
+ port->mstb = mstb;
+ mstb->mgr = port->mgr;
+ mstb->port_parent = port;
- /*
- * Make sure this port's memory allocation stays
- * around until its child MSTB releases it
- */
- drm_dp_mst_get_port_malloc(port);
- mutex_unlock(&mgr->lock);
+ /*
+ * Make sure this port's memory allocation stays
+ * around until its child MSTB releases it
+ */
+ drm_dp_mst_get_port_malloc(port);
+ mutex_unlock(&mgr->lock);
- /* And make sure we send a link address for this */
- ret = 1;
- break;
+ /* And make sure we send a link address for this */
+ ret = 1;
+ }
}
out:
goto error;
}
- if ((port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV ||
- port->pdt == DP_PEER_DEVICE_SST_SINK) &&
- port->port_num >= DP_MST_LOGICAL_PORT_0) {
+ if (port->pdt != DP_PEER_DEVICE_NONE &&
+ drm_dp_mst_is_dp_mst_end_device(port->pdt, port->mcs)) {
port->cached_edid = drm_get_edid(port->connector,
&port->aux.ddc);
drm_connector_set_tile_property(port->connector);
struct drm_dp_mst_port *port)
{
mutex_lock(&mgr->lock);
+ port->parent->num_ports--;
list_del(&port->next);
mutex_unlock(&mgr->lock);
drm_dp_mst_topology_put_port(port);
port->aux.dev = dev->dev;
port->aux.is_remote = true;
+ /* initialize the MST downstream port's AUX crc work queue */
+ drm_dp_remote_aux_init(&port->aux);
+
/*
* Make sure the memory allocation for our parent branch stays
* around until our own memory allocation is released
struct drm_dp_mst_port *port;
int old_ddps = 0, ret;
u8 new_pdt = DP_PEER_DEVICE_NONE;
+ bool new_mcs = 0;
bool created = false, send_link_addr = false, changed = false;
port = drm_dp_get_port(mstb, port_msg->port_number);
port->input = port_msg->input_port;
if (!port->input)
new_pdt = port_msg->peer_device_type;
- port->mcs = port_msg->mcs;
+ new_mcs = port_msg->mcs;
port->ddps = port_msg->ddps;
port->ldps = port_msg->legacy_device_plug_status;
port->dpcd_rev = port_msg->dpcd_revision;
mutex_lock(&mgr->lock);
drm_dp_mst_topology_get_port(port);
list_add(&port->next, &mstb->ports);
+ mstb->num_ports++;
mutex_unlock(&mgr->lock);
}
}
}
- ret = drm_dp_port_set_pdt(port, new_pdt);
+ ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
if (ret == 1) {
send_link_addr = true;
} else if (ret < 0) {
* we're coming out of suspend. In this case, always resend the link
* address if there's an MSTB on this port
*/
- if (!created && port->pdt == DP_PEER_DEVICE_MST_BRANCHING)
+ if (!created && port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
+ port->mcs)
send_link_addr = true;
if (port->connector)
{
struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
struct drm_dp_mst_port *port;
- int old_ddps, ret;
+ int old_ddps, old_input, ret, i;
u8 new_pdt;
+ bool new_mcs;
bool dowork = false, create_connector = false;
port = drm_dp_get_port(mstb, conn_stat->port_number);
}
old_ddps = port->ddps;
+ old_input = port->input;
port->input = conn_stat->input_port;
- port->mcs = conn_stat->message_capability_status;
port->ldps = conn_stat->legacy_device_plug_status;
port->ddps = conn_stat->displayport_device_plug_status;
}
new_pdt = port->input ? DP_PEER_DEVICE_NONE : conn_stat->peer_device_type;
-
- ret = drm_dp_port_set_pdt(port, new_pdt);
+ new_mcs = conn_stat->message_capability_status;
+ ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
if (ret == 1) {
dowork = true;
} else if (ret < 0) {
dowork = false;
}
+ if (!old_input && old_ddps != port->ddps && !port->ddps) {
+ for (i = 0; i < mgr->max_payloads; i++) {
+ struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
+ struct drm_dp_mst_port *port_validated;
+
+ if (!vcpi)
+ continue;
+
+ port_validated =
+ container_of(vcpi, struct drm_dp_mst_port, vcpi);
+ port_validated =
+ drm_dp_mst_topology_get_port_validated(mgr, port_validated);
+ if (!port_validated) {
+ mutex_lock(&mgr->payload_lock);
+ vcpi->num_slots = 0;
+ mutex_unlock(&mgr->payload_lock);
+ } else {
+ drm_dp_mst_topology_put_port(port_validated);
+ }
+ }
+ }
+
if (port->connector)
drm_modeset_unlock(&mgr->base.lock);
else if (create_connector)
ret = process_single_tx_qlock(mgr, txmsg, false);
if (ret == 1) {
/* txmsg is sent it should be in the slots now */
+ mgr->is_waiting_for_dwn_reply = true;
list_del(&txmsg->next);
} else if (ret) {
DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
+ mgr->is_waiting_for_dwn_reply = false;
list_del(&txmsg->next);
if (txmsg->seqno != -1)
txmsg->dst->tx_slots[txmsg->seqno] = NULL;
drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
}
- if (list_is_singular(&mgr->tx_msg_downq))
+ if (list_is_singular(&mgr->tx_msg_downq) &&
+ !mgr->is_waiting_for_dwn_reply)
process_single_down_tx_qlock(mgr);
mutex_unlock(&mgr->qlock);
}
path_res->avail_payload_bw_number);
port->available_pbn =
path_res->avail_payload_bw_number;
+ port->fec_capable = path_res->fec_capable;
}
}
mutex_lock(&mgr->qlock);
txmsg->state = DRM_DP_SIDEBAND_TX_RX;
mstb->tx_slots[slot] = NULL;
+ mgr->is_waiting_for_dwn_reply = false;
mutex_unlock(&mgr->qlock);
wake_up_all(&mgr->tx_waitq);
no_msg:
drm_dp_mst_topology_put_mstb(mstb);
clear_down_rep_recv:
+ mutex_lock(&mgr->qlock);
+ mgr->is_waiting_for_dwn_reply = false;
+ mutex_unlock(&mgr->qlock);
memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
return 0;
else if (msg->req_type == DP_RESOURCE_STATUS_NOTIFY)
guid = msg->u.resource_stat.guid;
- mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid);
+ if (guid)
+ mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid);
} else {
mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad);
}
switch (port->pdt) {
case DP_PEER_DEVICE_NONE:
case DP_PEER_DEVICE_MST_BRANCHING:
+ if (!port->mcs)
+ ret = connector_status_connected;
break;
case DP_PEER_DEVICE_SST_SINK:
* @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;
- int prev_slots, req_slots;
+ int prev_slots, prev_bw, req_slots;
topology_state = drm_atomic_get_mst_topology_state(state, mgr);
if (IS_ERR(topology_state))
if (pos->port == port) {
vcpi = pos;
prev_slots = vcpi->vcpi;
+ prev_bw = vcpi->pbn;
/*
* This should never happen, unless the driver tries
break;
}
}
- if (!vcpi)
+ if (!vcpi) {
prev_slots = 0;
+ prev_bw = 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,
port, prev_slots, req_slots);
+ DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] PBN %d -> %d\n",
+ port->connector->base.id, port->connector->name,
+ port, prev_bw, pbn);
/* Add the new allocation to the state */
if (!vcpi) {
list_add(&vcpi->next, &topology_state->vcpis);
}
vcpi->vcpi = req_slots;
+ vcpi->pbn = pbn;
return req_slots;
}
* drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
* @clock: dot clock for the mode
* @bpp: bpp for the mode.
+ * @dsc: DSC mode. If true, bpp has units of 1/16 of a bit per pixel
*
* This uses the formula in the spec to calculate the PBN value for a mode.
*/
-int drm_dp_calc_pbn_mode(int clock, int bpp)
+int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc)
{
/*
* margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
* peak_kbps *= (1006/1000)
* peak_kbps *= (64/54)
* peak_kbps *= 8 convert to bytes
+ *
+ * If the bpp is in units of 1/16, further divide by 16. Put this
+ * factor in the numerator rather than the denominator to avoid
+ * integer overflow
*/
+
+ if (dsc)
+ return DIV_ROUND_UP_ULL(mul_u32_u32(clock * (bpp / 16), 64 * 1006),
+ 8 * 54 * 1000 * 1000);
+
return DIV_ROUND_UP_ULL(mul_u32_u32(clock * bpp, 64 * 1006),
8 * 54 * 1000 * 1000);
}
struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
mutex_lock(&mgr->qlock);
- if (!list_empty(&mgr->tx_msg_downq))
+ if (!list_empty(&mgr->tx_msg_downq) && !mgr->is_waiting_for_dwn_reply)
process_single_down_tx_qlock(mgr);
mutex_unlock(&mgr->qlock);
}
if (port->connector)
port->mgr->cbs->destroy_connector(port->mgr, port->connector);
- drm_dp_port_set_pdt(port, DP_PEER_DEVICE_NONE);
+ drm_dp_port_set_pdt(port, DP_PEER_DEVICE_NONE, port->mcs);
drm_dp_mst_put_port_malloc(port);
}
kfree(mst_state);
}
+static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port,
+ struct drm_dp_mst_branch *branch)
+{
+ while (port->parent) {
+ if (port->parent == branch)
+ return true;
+
+ if (port->parent->port_parent)
+ port = port->parent->port_parent;
+ else
+ break;
+ }
+ return false;
+}
+
+static inline
+int drm_dp_mst_atomic_check_bw_limit(struct drm_dp_mst_branch *branch,
+ struct drm_dp_mst_topology_state *mst_state)
+{
+ struct drm_dp_mst_port *port;
+ struct drm_dp_vcpi_allocation *vcpi;
+ int pbn_limit = 0, pbn_used = 0;
+
+ list_for_each_entry(port, &branch->ports, next) {
+ if (port->mstb)
+ if (drm_dp_mst_atomic_check_bw_limit(port->mstb, mst_state))
+ return -ENOSPC;
+
+ if (port->available_pbn > 0)
+ pbn_limit = port->available_pbn;
+ }
+ DRM_DEBUG_ATOMIC("[MST BRANCH:%p] branch has %d PBN available\n",
+ branch, pbn_limit);
+
+ list_for_each_entry(vcpi, &mst_state->vcpis, next) {
+ if (!vcpi->pbn)
+ continue;
+
+ if (drm_dp_mst_port_downstream_of_branch(vcpi->port, branch))
+ pbn_used += vcpi->pbn;
+ }
+ DRM_DEBUG_ATOMIC("[MST BRANCH:%p] branch used %d PBN\n",
+ branch, pbn_used);
+
+ if (pbn_used > pbn_limit) {
+ DRM_DEBUG_ATOMIC("[MST BRANCH:%p] No available bandwidth\n",
+ branch);
+ return -ENOSPC;
+ }
+ return 0;
+}
+
static inline int
-drm_dp_mst_atomic_check_topology_state(struct drm_dp_mst_topology_mgr *mgr,
- struct drm_dp_mst_topology_state *mst_state)
+drm_dp_mst_atomic_check_vcpi_alloc_limit(struct drm_dp_mst_topology_mgr *mgr,
+ struct drm_dp_mst_topology_state *mst_state)
{
struct drm_dp_vcpi_allocation *vcpi;
int avail_slots = 63, payload_count = 0;
}
/**
+ * drm_dp_mst_add_affected_dsc_crtcs
+ * @state: Pointer to the new struct drm_dp_mst_topology_state
+ * @mgr: MST topology manager
+ *
+ * Whenever there is a change in mst topology
+ * DSC configuration would have to be recalculated
+ * therefore we need to trigger modeset on all affected
+ * CRTCs in that topology
+ *
+ * See also:
+ * drm_dp_mst_atomic_enable_dsc()
+ */
+int drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr)
+{
+ struct drm_dp_mst_topology_state *mst_state;
+ struct drm_dp_vcpi_allocation *pos;
+ struct drm_connector *connector;
+ struct drm_connector_state *conn_state;
+ struct drm_crtc *crtc;
+ struct drm_crtc_state *crtc_state;
+
+ mst_state = drm_atomic_get_mst_topology_state(state, mgr);
+
+ if (IS_ERR(mst_state))
+ return -EINVAL;
+
+ list_for_each_entry(pos, &mst_state->vcpis, next) {
+
+ connector = pos->port->connector;
+
+ if (!connector)
+ return -EINVAL;
+
+ conn_state = drm_atomic_get_connector_state(state, connector);
+
+ if (IS_ERR(conn_state))
+ return PTR_ERR(conn_state);
+
+ crtc = conn_state->crtc;
+
+ if (WARN_ON(!crtc))
+ return -EINVAL;
+
+ if (!drm_dp_mst_dsc_aux_for_port(pos->port))
+ continue;
+
+ crtc_state = drm_atomic_get_crtc_state(mst_state->base.state, crtc);
+
+ if (IS_ERR(crtc_state))
+ return PTR_ERR(crtc_state);
+
+ DRM_DEBUG_ATOMIC("[MST MGR:%p] Setting mode_changed flag on CRTC %p\n",
+ mgr, crtc);
+
+ crtc_state->mode_changed = true;
+ }
+ return 0;
+}
+EXPORT_SYMBOL(drm_dp_mst_add_affected_dsc_crtcs);
+
+/**
+ * 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
* @state: Pointer to the new &struct drm_dp_mst_topology_state
int i, ret = 0;
for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) {
- ret = drm_dp_mst_atomic_check_topology_state(mgr, mst_state);
+ if (!mgr->mst_state)
+ continue;
+
+ ret = drm_dp_mst_atomic_check_vcpi_alloc_limit(mgr, mst_state);
+ if (ret)
+ break;
+ ret = drm_dp_mst_atomic_check_bw_limit(mgr->mst_primary, mst_state);
if (ret)
break;
}
{
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 / platform / kernel / linux-rpi.git / blobdiff