usb: add inline helper method for CC lines

Expressing logic for CC lines can get very verbose. Add helper inline
methods that logical describe the condition we are testing to clean up
call sites.

BRANCH=none
BUG=none
TEST=Builds, no functional change.

Change-Id: I48c117437bc14f3c55473df7f7c778b55af2706d
Signed-off-by: Jett Rink <jettrink@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1589906
Reviewed-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-by: Sam Hurst <shurst@google.com>

2 files changed, 44 insertions, 5 deletions

diff --git a/include/usb_pd_tcpm.h b/include/usb_pd_tcpm.h
index 874b231dce..1bfae8b540 100644
--- a/include/usb_pd_tcpm.h
+++ b/include/usb_pd_tcpm.h
@@ -64,6 +64,47 @@ enum tcpc_transmit_complete {
 	TCPC_TX_COMPLETE_FAILED =    2,
 };
 
+/**
+ * Returns whether the sink has detected a Rp resistor on the other side.
+ */
+static inline int cc_is_rp(int cc)
+{
+	return (cc == TYPEC_CC_VOLT_RP_DEF) || (cc == TYPEC_CC_VOLT_RP_1_5) ||
+	       (cc == TYPEC_CC_VOLT_RP_3_0);
+}
+
+/**
+ * Returns true if both CC lines are completely open.
+ */
+static inline int cc_is_open(int cc1, int cc2)
+{
+	return cc1 == TYPEC_CC_VOLT_OPEN && cc2 == TYPEC_CC_VOLT_OPEN;
+}
+
+/**
+ * Returns true if we detect the port partner is a snk debug accessory.
+ */
+static inline int cc_is_snk_dbg_acc(int cc1, int cc2)
+{
+	return cc1 == TYPEC_CC_VOLT_RD && cc2 == TYPEC_CC_VOLT_RD;
+}
+
+/**
+ * Returns true if the port partner is an audio accessory.
+ */
+static inline int cc_is_audio_acc(int cc1, int cc2)
+{
+	return cc1 == TYPEC_CC_VOLT_RA && cc2 == TYPEC_CC_VOLT_RA;
+}
+
+/**
+ * Returns true if the port partner is presenting at least one Rd
+ */
+static inline int cc_is_at_least_one_rd(int cc1, int cc2)
+{
+	return cc1 == TYPEC_CC_VOLT_RD || cc2 == TYPEC_CC_VOLT_RD;
+}
+
 struct tcpm_drv {
 	/**
 	 * Initialize TCPM driver and wait for TCPC readiness.
diff --git a/include/usb_tc_ctvpd_sm.h b/include/usb_tc_ctvpd_sm.h
index 3b47d35ffa..8e0e1eaf2f 100644
--- a/include/usb_tc_ctvpd_sm.h
+++ b/include/usb_tc_ctvpd_sm.h
@@ -1378,9 +1378,9 @@ static unsigned int tc_state_ct_attach_wait_unsupported_run(int port)
 	/* Check CT CC for connection */
 	vpd_ct_get_cc(&cc1, &cc2);
 
-	if (cc1 == TYPEC_CC_VOLT_RD || cc2 == TYPEC_CC_VOLT_RD)
+	if (cc_is_at_least_one_rd(cc1, cc2))
 		new_cc_state = PD_CC_DFP_ATTACHED;
-	else if (cc1 == TYPEC_CC_VOLT_RA && cc2 == TYPEC_CC_VOLT_RA)
+	else if (cc_is_audio_acc(cc1, cc2))
 		new_cc_state = PD_CC_AUDIO_ACC;
 	else /* (cc1 == TYPEC_CC_VOLT_OPEN or cc2 == TYPEC_CC_VOLT_OPEN */
 		new_cc_state = PD_CC_NONE;
@@ -1545,9 +1545,7 @@ static unsigned int tc_state_ct_unattached_unsupported_run(int port)
 	 * least one of the Charge-Through port’s CC pins or SRC.Ra state
 	 * on both the CC1 and CC2 pins.
 	 */
-	if ((cc1 == TYPEC_CC_VOLT_RD || cc2 == TYPEC_CC_VOLT_RD) ||
-			(cc1 == TYPEC_CC_VOLT_RA &&
-			cc2 == TYPEC_CC_VOLT_RA)) {
+	if (cc_is_at_least_one_rd(cc1, cc2) || cc_is_audio_acc(cc1, cc2)) {
 		set_state(port, TC_OBJ(port),
 				tc_state_ct_attach_wait_unsupported);
 		return 0;