[PATCH 1/5] usb: typec: tcpm: source pdo selection update

[Li Jun <jun.li@nxp.com>]

Instead of only compare between the same pdo type of sink and source,
this patch update the source pdo selection by checking the source pdo
voltage range is within that of sink.

Signed-off-by: Li Jun <jun.li@nxp.com>
---
 drivers/usb/typec/tcpm.c | 101 +++++++++++++++++------------------------------
 1 file changed, 37 insertions(+), 64 deletions(-)

diff --git a/drivers/usb/typec/tcpm.c b/drivers/usb/typec/tcpm.c
index cd48a99..20f7ca8 100644
--- a/drivers/usb/typec/tcpm.c
+++ b/drivers/usb/typec/tcpm.c
@@ -1765,7 +1765,9 @@ static int tcpm_pd_check_request(struct tcpm_port *port)
 static int tcpm_pd_select_pdo(struct tcpm_port *port, int *sink_pdo,
 			      int *src_pdo)
 {
-	unsigned int i, j, max_mw = 0, max_mv = 0, mw = 0, mv = 0, ma = 0;
+	unsigned int i, j, max_src_mv = 0, min_src_mv = 0, max_mw = 0,
+		     max_mv = 0, src_mw = 0, src_ma = 0, max_snk_mv = 0,
+		     min_snk_mv = 0;
 	int ret = -EINVAL;
 
 	/*
@@ -1777,70 +1779,41 @@ static int tcpm_pd_select_pdo(struct tcpm_port *port, int *sink_pdo,
 		enum pd_pdo_type type = pdo_type(pdo);
 
 		if (type == PDO_TYPE_FIXED) {
-			for (j = 0; j < port->nr_fixed; j++) {
-				if (pdo_fixed_voltage(pdo) ==
-				    pdo_fixed_voltage(port->snk_pdo[j])) {
-					ma = min_current(pdo, port->snk_pdo[j]);
-					mv = pdo_fixed_voltage(pdo);
-					mw = ma * mv / 1000;
-					if (mw > max_mw ||
-					    (mw == max_mw && mv > max_mv)) {
-						ret = 0;
-						*src_pdo = i;
-						*sink_pdo = j;
-						max_mw = mw;
-						max_mv = mv;
-					}
-					/* There could only be one fixed pdo
-					 * at a specific voltage level.
-					 * So breaking here.
-					 */
-					break;
-				}
-			}
-		} else if (type == PDO_TYPE_BATT) {
-			for (j = port->nr_fixed;
-			     j < port->nr_fixed +
-				 port->nr_batt;
-			     j++) {
-				if (pdo_min_voltage(pdo) >=
-				     pdo_min_voltage(port->snk_pdo[j]) &&
-				     pdo_max_voltage(pdo) <=
-				     pdo_max_voltage(port->snk_pdo[j])) {
-					mw = min_power(pdo, port->snk_pdo[j]);
-					mv = pdo_min_voltage(pdo);
-					if (mw > max_mw ||
-					    (mw == max_mw && mv > max_mv)) {
-						ret = 0;
-						*src_pdo = i;
-						*sink_pdo = j;
-						max_mw = mw;
-						max_mv = mv;
-					}
-				}
+			max_src_mv = pdo_fixed_voltage(pdo);
+			min_src_mv = max_src_mv;
+		} else {
+			max_src_mv = pdo_max_voltage(pdo);
+			min_src_mv = pdo_min_voltage(pdo);
+		}
+
+		if (type == PDO_TYPE_BATT) {
+			src_mw = pdo_max_power(pdo);
+		} else {
+			src_ma = pdo_max_current(pdo);
+			src_mw = src_ma * min_src_mv / 1000;
+		}
+
+		for (j = 0; j < port->nr_snk_pdo; j++) {
+			pdo = port->snk_pdo[j];
+
+			if (pdo_type(pdo) == PDO_TYPE_FIXED) {
+				min_snk_mv = pdo_fixed_voltage(pdo);
+				max_snk_mv = pdo_fixed_voltage(pdo);
+			} else {
+				min_snk_mv = pdo_min_voltage(pdo);
+				max_snk_mv = pdo_max_voltage(pdo);
 			}
-		} else if (type == PDO_TYPE_VAR) {
-			for (j = port->nr_fixed +
-				 port->nr_batt;
-			     j < port->nr_fixed +
-				 port->nr_batt +
-				 port->nr_var;
-			     j++) {
-				if (pdo_min_voltage(pdo) >=
-				     pdo_min_voltage(port->snk_pdo[j]) &&
-				     pdo_max_voltage(pdo) <=
-				     pdo_max_voltage(port->snk_pdo[j])) {
-					ma = min_current(pdo, port->snk_pdo[j]);
-					mv = pdo_min_voltage(pdo);
-					mw = ma * mv / 1000;
-					if (mw > max_mw ||
-					    (mw == max_mw && mv > max_mv)) {
-						ret = 0;
-						*src_pdo = i;
-						*sink_pdo = j;
-						max_mw = mw;
-						max_mv = mv;
-					}
+
+			if (max_src_mv <= max_snk_mv &&
+				min_src_mv >= min_snk_mv) {
+				/* Prefer higher voltages if available */
+				if ((src_mw == max_mw && min_src_mv > max_mv) ||
+							src_mw > max_mw) {
+					*src_pdo = i;
+					*sink_pdo = j;
+					max_mw = src_mw;
+					max_mv = min_src_mv;
+					ret = 0;
 				}
 			}
 		}
-- 
2.7.4