pd: combine src/snk dr_swap states into one dr_swap state

Combine source and sink data role swap states into one data
role swap state. This saves 128B of flash.

Also add DUAL_ROLE_IF_ELSE macro to clean up all the places
we check our role and need to know if we are DUAL_ROLE or not.

BUG=none
BRANCH=samus
TEST=load onto two samus' and try data swaps from both sink and
source sides and make sure they get rejected and go back to the
correct ready state. load onto zinger and make sure we successfully
data swap when connected to samus.

Change-Id: I57744593ce291e512cb254b08745115de365cab4
Signed-off-by: Alec Berg <alecaberg@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/264855
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>

2 files changed, 46 insertions, 86 deletions

diff --git a/common/usb_pd_protocol.c b/common/usb_pd_protocol.c
index f78f8f86e2..710db2b9ed 100644
--- a/common/usb_pd_protocol.c
+++ b/common/usb_pd_protocol.c
@@ -172,6 +172,16 @@ static const uint8_t dec4b5b[] = {
 #define CC_RP(cc)  (cc >= PD_SNK_VA)
 #define UFP_GET_POLARITY(cc1, cc2) (CC_RP(cc2))
 
+#ifdef CONFIG_USB_PD_DUAL_ROLE
+#define DUAL_ROLE_IF_ELSE(port, sink_clause, src_clause) \
+	(pd[port].power_role == PD_ROLE_SINK ? (sink_clause) : (src_clause))
+#else
+#define DUAL_ROLE_IF_ELSE(port, sink_clause, src_clause) (src_clause)
+#endif
+
+#define READY_RETURN_STATE(port) DUAL_ROLE_IF_ELSE(port, PD_STATE_SNK_READY, \
+							 PD_STATE_SRC_READY)
+
 /*
  * Type C power source charge current limits are identified by their cc
  * voltage (set by selecting the proper Rd resistor). Any voltage below
@@ -293,13 +303,13 @@ static const char * const pd_state_names[] = {
 	"SNK_DISCONNECTED", "SNK_DISCONNECTED_DEBOUNCE",
 	"SNK_HARD_RESET_RECOVER",
 	"SNK_DISCOVERY", "SNK_REQUESTED", "SNK_TRANSITION", "SNK_READY",
-	"SNK_DR_SWAP", "SNK_SWAP_INIT", "SNK_SWAP_SNK_DISABLE",
+	"SNK_SWAP_INIT", "SNK_SWAP_SNK_DISABLE",
 	"SNK_SWAP_SRC_DISABLE", "SNK_SWAP_STANDBY", "SNK_SWAP_COMPLETE",
 #endif /* CONFIG_USB_PD_DUAL_ROLE */
 	"SRC_DISCONNECTED", "SRC_DISCONNECTED_DEBOUNCE", "SRC_ACCESSORY",
 	"SRC_HARD_RESET_RECOVER", "SRC_STARTUP",
 	"SRC_DISCOVERY", "SRC_NEGOCIATE", "SRC_ACCEPTED", "SRC_POWERED",
-	"SRC_TRANSITION", "SRC_READY", "SRC_GET_SNK_CAP", "SRC_DR_SWAP",
+	"SRC_TRANSITION", "SRC_READY", "SRC_GET_SNK_CAP", "DR_SWAP",
 #ifdef CONFIG_USB_PD_DUAL_ROLE
 	"SRC_SWAP_INIT", "SRC_SWAP_SNK_DISABLE", "SRC_SWAP_SRC_DISABLE",
 	"SRC_SWAP_STANDBY",
@@ -332,16 +342,14 @@ int pd_is_connected(int port)
 	if (pd[port].task_state == PD_STATE_DISABLED)
 		return 0;
 
-#ifdef CONFIG_USB_PD_DUAL_ROLE
-	/* Check if sink is connected */
-	if (pd[port].power_role == PD_ROLE_SINK)
-		return pd[port].task_state != PD_STATE_SNK_DISCONNECTED &&
-		      pd[port].task_state != PD_STATE_SNK_DISCONNECTED_DEBOUNCE;
-#endif
-	/* Must be a source */
-	return pd[port].task_state != PD_STATE_SRC_DISCONNECTED &&
-	       pd[port].task_state != PD_STATE_SRC_DISCONNECTED_DEBOUNCE &&
-	       pd[port].task_state != PD_STATE_SRC_ACCESSORY;
+	return DUAL_ROLE_IF_ELSE(port,
+		/* sink */
+		pd[port].task_state != PD_STATE_SNK_DISCONNECTED &&
+		pd[port].task_state != PD_STATE_SNK_DISCONNECTED_DEBOUNCE,
+		/* source */
+		pd[port].task_state != PD_STATE_SRC_DISCONNECTED &&
+		pd[port].task_state != PD_STATE_SRC_DISCONNECTED_DEBOUNCE &&
+		pd[port].task_state != PD_STATE_SRC_ACCESSORY);
 }
 
 static inline void set_state(int port, enum pd_states next_state)
@@ -735,13 +743,8 @@ static void bist_mode_2_rx(int port)
 		CPRINTF("BIST RX TO\n");
 	}
 	/* Set to appropriate port disconnected state */
-#ifdef CONFIG_USB_PD_DUAL_ROLE
-	set_state(port, pd[port].power_role == PD_ROLE_SINK ?
-		  PD_STATE_SNK_DISCONNECTED : PD_STATE_SRC_DISCONNECTED);
-#else
-	set_state(port, PD_STATE_SRC_DISCONNECTED);
-#endif
-
+	set_state(port, DUAL_ROLE_IF_ELSE(port, PD_STATE_SNK_DISCONNECTED,
+						PD_STATE_SRC_DISCONNECTED));
 }
 #endif
 
@@ -784,13 +787,8 @@ static void bist_mode_2_tx(int port)
 	/* finish and cleanup transmit */
 	pd_tx_done(port, pd[port].polarity);
 	/* Set to appropriate port disconnected state */
-#ifdef CONFIG_USB_PD_DUAL_ROLE
-	set_state(port, pd[port].power_role == PD_ROLE_SINK ?
-		  PD_STATE_SNK_DISCONNECTED :
-		  PD_STATE_SRC_DISCONNECTED);
-#else
-	set_state(port, PD_STATE_SRC_DISCONNECTED);
-#endif
+	set_state(port, DUAL_ROLE_IF_ELSE(port, PD_STATE_SNK_DISCONNECTED,
+						PD_STATE_SRC_DISCONNECTED));
 }
 
 static void queue_vdm(int port, uint32_t *header, const uint32_t *data,
@@ -886,12 +884,8 @@ static void execute_hard_reset(int port)
 static void execute_soft_reset(int port)
 {
 	pd[port].msg_id = 0;
-#ifdef CONFIG_USB_PD_DUAL_ROLE
-	set_state(port, pd[port].power_role == PD_ROLE_SINK ?
-			PD_STATE_SNK_DISCOVERY : PD_STATE_SRC_DISCOVERY);
-#else
-	set_state(port, PD_STATE_SRC_DISCOVERY);
-#endif
+	set_state(port, DUAL_ROLE_IF_ELSE(port, PD_STATE_SNK_DISCOVERY,
+						PD_STATE_SRC_DISCOVERY));
 	/* if flag to disable PD comms after soft reset, then disable comms */
 	if (pd[port].flags & PD_FLAGS_SFT_RST_DIS_COMM)
 		pd_comm_enable(0);
@@ -1099,12 +1093,9 @@ static void handle_data_request(int port, uint16_t head,
 		break;
 	case PD_DATA_BIST:
 		/* If not in READY state, then don't start BIST */
-#ifdef CONFIG_USB_PD_DUAL_ROLE
-		if (pd[port].task_state == PD_STATE_SRC_READY ||
-		    pd[port].task_state == PD_STATE_SNK_READY) {
-#else
-		if (pd[port].task_state == PD_STATE_SRC_READY) {
-#endif
+		if (DUAL_ROLE_IF_ELSE(port,
+				pd[port].task_state == PD_STATE_SNK_READY,
+				pd[port].task_state == PD_STATE_SRC_READY)) {
 			/* currently only support sending bist carrier mode 2 */
 			if ((payload[0] >> 28) == 5) {
 				/* bist data object mode is 2 */
@@ -1144,12 +1135,10 @@ void pd_request_power_swap(int port)
 
 void pd_request_data_swap(int port)
 {
-	if (pd[port].task_state == PD_STATE_SRC_READY)
-		set_state(port, PD_STATE_SRC_DR_SWAP);
-#ifdef CONFIG_USB_PD_DUAL_ROLE
-	else if (pd[port].task_state == PD_STATE_SNK_READY)
-		set_state(port, PD_STATE_SNK_DR_SWAP);
-#endif
+	if (DUAL_ROLE_IF_ELSE(port,
+				pd[port].task_state == PD_STATE_SNK_READY,
+				pd[port].task_state == PD_STATE_SRC_READY))
+		set_state(port, PD_STATE_DR_SWAP);
 	task_wake(PORT_TO_TASK_ID(port));
 }
 
@@ -1221,11 +1210,9 @@ static void handle_ctrl_request(int port, uint16_t head,
 #endif
 	case PD_CTRL_REJECT:
 	case PD_CTRL_WAIT:
-		if (pd[port].task_state == PD_STATE_SRC_DR_SWAP)
-			set_state(port, PD_STATE_SRC_READY);
+		if (pd[port].task_state == PD_STATE_DR_SWAP)
+			set_state(port, READY_RETURN_STATE(port));
 #ifdef CONFIG_USB_PD_DUAL_ROLE
-		else if (pd[port].task_state == PD_STATE_SNK_DR_SWAP)
-			set_state(port, PD_STATE_SNK_READY);
 		else if (pd[port].task_state == PD_STATE_SRC_SWAP_INIT)
 			set_state(port, PD_STATE_SRC_READY);
 		else if (pd[port].task_state == PD_STATE_SNK_SWAP_INIT)
@@ -1238,17 +1225,13 @@ static void handle_ctrl_request(int port, uint16_t head,
 	case PD_CTRL_ACCEPT:
 		if (pd[port].task_state == PD_STATE_SOFT_RESET) {
 			execute_soft_reset(port);
-		} else if (pd[port].task_state == PD_STATE_SRC_DR_SWAP) {
+		} else if (pd[port].task_state == PD_STATE_DR_SWAP) {
 			/* switch data role */
 			pd_dr_swap(port);
-			set_state(port, PD_STATE_SRC_READY);
+			set_state(port, READY_RETURN_STATE(port));
 		}
 #ifdef CONFIG_USB_PD_DUAL_ROLE
-		else if (pd[port].task_state == PD_STATE_SNK_DR_SWAP) {
-			/* switch data role */
-			pd_dr_swap(port);
-			set_state(port, PD_STATE_SNK_READY);
-		} else if (pd[port].task_state == PD_STATE_SRC_SWAP_INIT) {
+		else if (pd[port].task_state == PD_STATE_SRC_SWAP_INIT) {
 			/* explicit contract goes away for power swap */
 			pd[port].flags &= ~PD_FLAGS_EXPLICIT_CONTRACT;
 			set_state(port, PD_STATE_SRC_SWAP_SNK_DISABLE);
@@ -1277,10 +1260,10 @@ static void handle_ctrl_request(int port, uint16_t head,
 			 * immediately requesting another swap.
 			 */
 			pd[port].flags &= ~PD_FLAGS_CHECK_PR_ROLE;
-			if (pd[port].power_role == PD_ROLE_SINK)
-				set_state(port, PD_STATE_SNK_SWAP_SNK_DISABLE);
-			else
-				set_state(port, PD_STATE_SRC_SWAP_SNK_DISABLE);
+			set_state(port,
+				  DUAL_ROLE_IF_ELSE(port,
+					PD_STATE_SNK_SWAP_SNK_DISABLE,
+					PD_STATE_SRC_SWAP_SNK_DISABLE));
 		} else {
 			send_control(port, PD_CTRL_REJECT);
 		}
@@ -2246,7 +2229,7 @@ void pd_task(void)
 						  PD_T_SENDER_RESPONSE,
 						  PD_STATE_SRC_READY);
 			break;
-		case PD_STATE_SRC_DR_SWAP:
+		case PD_STATE_DR_SWAP:
 			if (pd[port].last_state != pd[port].task_state) {
 				res = send_control(port, PD_CTRL_DR_SWAP);
 				if (res < 0) {
@@ -2258,14 +2241,14 @@ void pd_task(void)
 					 */
 					set_state(port, res == -1 ?
 						   PD_STATE_SOFT_RESET :
-						   PD_STATE_SRC_READY);
+						   READY_RETURN_STATE(port));
 					break;
 				}
 				/* Wait for accept or reject */
 				set_state_timeout(port,
 						  get_time().val +
 						  PD_T_SENDER_RESPONSE,
-						  PD_STATE_SRC_READY);
+						  READY_RETURN_STATE(port));
 			}
 			break;
 #ifdef CONFIG_USB_PD_DUAL_ROLE
@@ -2593,28 +2576,6 @@ void pd_task(void)
 			/* Sent all messages, don't need to wake very often */
 			timeout = 200*MSEC;
 			break;
-		case PD_STATE_SNK_DR_SWAP:
-			if (pd[port].last_state != pd[port].task_state) {
-				res = send_control(port, PD_CTRL_DR_SWAP);
-				if (res < 0) {
-					timeout = 10*MSEC;
-					/*
-					 * If failed to get goodCRC, send
-					 * soft reset, otherwise ignore
-					 * failure.
-					 */
-					set_state(port, res == -1 ?
-						   PD_STATE_SOFT_RESET :
-						   PD_STATE_SNK_READY);
-					break;
-				}
-				/* Wait for accept or reject */
-				set_state_timeout(port,
-						  get_time().val +
-						  PD_T_SENDER_RESPONSE,
-						  PD_STATE_SRC_READY);
-			}
-			break;
 		case PD_STATE_SNK_SWAP_INIT:
 			if (pd[port].last_state != pd[port].task_state) {
 				res = send_control(port, PD_CTRL_PR_SWAP);
diff --git a/include/usb_pd.h b/include/usb_pd.h
index 33460bb732..e79e2d907c 100644
--- a/include/usb_pd.h
+++ b/include/usb_pd.h
@@ -594,7 +594,6 @@ enum pd_states {
 	PD_STATE_SNK_REQUESTED,
 	PD_STATE_SNK_TRANSITION,
 	PD_STATE_SNK_READY,
-	PD_STATE_SNK_DR_SWAP,
 
 	PD_STATE_SNK_SWAP_INIT,
 	PD_STATE_SNK_SWAP_SNK_DISABLE,
@@ -615,7 +614,7 @@ enum pd_states {
 	PD_STATE_SRC_TRANSITION,
 	PD_STATE_SRC_READY,
 	PD_STATE_SRC_GET_SINK_CAP,
-	PD_STATE_SRC_DR_SWAP,
+	PD_STATE_DR_SWAP,
 
 #ifdef CONFIG_USB_PD_DUAL_ROLE
 	PD_STATE_SRC_SWAP_INIT,