Use a template for PD message headers

The new tempate variable sets the data role, power role, and
specification revision in one fell swoop.  It's used by the PE and DPM
alike for creating messages, and in the future it may have a part in
determining if we're doing PD 2.0 or 3.0.

lib/include/pdb_pe.h

@@ -45,6 +45,8 @@ struct pdb_pe {
 
     /* PE mailbox for received PD messages */
     mailbox_t mailbox;
+    /* PD message header template */
+    uint16_t hdr_template;
 
     /* The received message we're currently working with */
     union pd_msg *_message;

lib/src/policy_engine.c

@@ -409,8 +409,8 @@ static enum policy_engine_state pe_sink_get_source_cap(struct pdb_config *cfg)
     /* Get a message object */
     union pd_msg *get_source_cap = chPoolAlloc(&pdb_msg_pool);
     /* Make a Get_Source_Cap message */
-    get_source_cap->hdr = PD_MSGTYPE_GET_SOURCE_CAP | PD_DATAROLE_UFP
-        | PD_SPECREV_2_0 | PD_POWERROLE_SINK | PD_NUMOBJ(0);
+    get_source_cap->hdr = cfg->pe.hdr_template | PD_MSGTYPE_GET_SOURCE_CAP
+        | PD_NUMOBJ(0);
     /* Transmit the Get_Source_Cap */
     chMBPost(&cfg->prl.tx_mailbox, (msg_t) get_source_cap, TIME_IMMEDIATE);
     chEvtSignal(cfg->prl.tx_thread, PDB_EVT_PRLTX_MSG_TX);
@@ -503,8 +503,7 @@ static enum policy_engine_state pe_sink_soft_reset(struct pdb_config *cfg)
     /* Get a message object */
     union pd_msg *accept = chPoolAlloc(&pdb_msg_pool);
     /* Make an Accept message */
-    accept->hdr = PD_MSGTYPE_ACCEPT | PD_DATAROLE_UFP | PD_SPECREV_2_0
-        | PD_POWERROLE_SINK | PD_NUMOBJ(0);
+    accept->hdr = cfg->pe.hdr_template | PD_MSGTYPE_ACCEPT | PD_NUMOBJ(0);
     /* Transmit the Accept */
     chMBPost(&cfg->prl.tx_mailbox, (msg_t) accept, TIME_IMMEDIATE);
     chEvtSignal(cfg->prl.tx_thread, PDB_EVT_PRLTX_MSG_TX);
@@ -533,8 +532,7 @@ static enum policy_engine_state pe_sink_send_soft_reset(struct pdb_config *cfg)
     /* Get a message object */
     union pd_msg *softrst = chPoolAlloc(&pdb_msg_pool);
     /* Make a Soft_Reset message */
-    softrst->hdr = PD_MSGTYPE_SOFT_RESET | PD_DATAROLE_UFP | PD_SPECREV_2_0
-        | PD_POWERROLE_SINK | PD_NUMOBJ(0);
+    softrst->hdr = cfg->pe.hdr_template | PD_MSGTYPE_SOFT_RESET | PD_NUMOBJ(0);
     /* Transmit the soft reset */
     chMBPost(&cfg->prl.tx_mailbox, (msg_t) softrst, TIME_IMMEDIATE);
     chEvtSignal(cfg->prl.tx_thread, PDB_EVT_PRLTX_MSG_TX);
@@ -593,8 +591,7 @@ static enum policy_engine_state pe_sink_send_reject(struct pdb_config *cfg)
     /* Get a message object */
     union pd_msg *reject = chPoolAlloc(&pdb_msg_pool);
     /* Make a Reject message */
-    reject->hdr = PD_MSGTYPE_REJECT | PD_DATAROLE_UFP | PD_SPECREV_2_0
-        | PD_POWERROLE_SINK | PD_NUMOBJ(0);
+    reject->hdr = cfg->pe.hdr_template | PD_MSGTYPE_REJECT | PD_NUMOBJ(0);
 
     /* Transmit the message */
     chMBPost(&cfg->prl.tx_mailbox, (msg_t) reject, TIME_IMMEDIATE);
@@ -655,6 +652,8 @@ static THD_FUNCTION(PolicyEngine, vcfg) {
     chMBObjectInit(&cfg->pe.mailbox, cfg->pe._mailbox_queue, PDB_MSG_POOL_SIZE);
     /* Initialize the old_tcc_match */
     cfg->pe._old_tcc_match = -1;
+    /* Initialize the PD message header template */
+    cfg->pe.hdr_template = PD_DATAROLE_UFP | PD_SPECREV_2_0 | PD_POWERROLE_SINK;
 
     while (true) {
         switch (state) {

src/device_policy_manager.c

@@ -75,8 +75,8 @@ bool pdbs_dpm_evaluate_capability(struct pdb_config *cfg,
             if (PD_PDO_SRC_FIXED_VOLTAGE_GET(capabilities, i) == scfg->v
                     && PD_PDO_SRC_FIXED_CURRENT_GET(capabilities, i) >= scfg->i) {
                 /* We got what we wanted, so build a request for that */
-                request->hdr = PD_MSGTYPE_REQUEST | PD_DATAROLE_UFP |
-                    PD_SPECREV_2_0 | PD_POWERROLE_SINK | PD_NUMOBJ(1);
+                request->hdr = cfg->pe.hdr_template | PD_MSGTYPE_REQUEST
+                    | PD_NUMOBJ(1);
                 if (scfg->flags & PDBS_CONFIG_FLAGS_GIVEBACK) {
                     /* GiveBack enabled */
                     request->obj[0] = PD_RDO_FV_MIN_CURRENT_SET(DPM_MIN_CURRENT)
@@ -102,8 +102,7 @@ bool pdbs_dpm_evaluate_capability(struct pdb_config *cfg,
         }
     }
     /* Nothing matched (or no configuration), so get 5 V at low current */
-    request->hdr = PD_MSGTYPE_REQUEST | PD_DATAROLE_UFP |
-        PD_SPECREV_2_0 | PD_POWERROLE_SINK | PD_NUMOBJ(1);
+    request->hdr = cfg->pe.hdr_template | PD_MSGTYPE_REQUEST | PD_NUMOBJ(1);
     request->obj[0] = PD_RDO_FV_MAX_CURRENT_SET(DPM_MIN_CURRENT)
         | PD_RDO_FV_CURRENT_SET(DPM_MIN_CURRENT)
         | PD_RDO_NO_USB_SUSPEND
@@ -166,8 +165,8 @@ void pdbs_dpm_get_sink_capability(struct pdb_config *cfg, union pd_msg *cap)
     }
 
     /* Set the Sink_Capabilities message header */
-    cap->hdr = PD_MSGTYPE_SINK_CAPABILITIES | PD_DATAROLE_UFP | PD_SPECREV_2_0
-        | PD_POWERROLE_SINK | PD_NUMOBJ(numobj);
+    cap->hdr = cfg->pe.hdr_template | PD_MSGTYPE_SINK_CAPABILITIES
+        | PD_NUMOBJ(numobj);
 }
 
 bool pdbs_dpm_giveback_enabled(struct pdb_config *cfg)