ec/google/chromeec: Split wait-loop for DP and HPD flags

Split wait-loop for DP and HPD flags as below -
- google_chromeec_wait_for_hpd
- google_chromeec_wait_for_dp_mode_entry

BUG=b:247670186
TEST=Verify display over TCSS and its impact on boot time for
google/rex

Signed-off-by: Kapil Porwal <kapilporwal@google.com>
Change-Id: I3e565d6134f6433930916071e94d56d92dc6cb06
Reviewed-on: https://review.coreboot.org/c/coreboot/+/76370
Reviewed-by: Subrata Banik <subratabanik@google.com>
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

3 files changed, 54 insertions, 10 deletions

diff --git a/src/ec/google/chromeec/ec.c b/src/ec/google/chromeec/ec.c
index a3b1fe3045..c950673c65 100644
--- a/src/ec/google/chromeec/ec.c
+++ b/src/ec/google/chromeec/ec.c
@@ -1383,15 +1383,29 @@ int google_chromeec_wait_for_displayport(long timeout_ms)
 	return ret;
 }
 
-int google_chromeec_wait_for_dp_hpd(int port, long timeout_ms)
+/**
+ * Check for given flag in PD mux info for a port.
+ *
+ * @param port  Type-C port number
+ *        flag  Flag to check
+ * @return	1: Flag is set. 0: Flag is not set.
+ */
+static int google_chromeec_check_mux_flag(int port, uint8_t flag)
+{
+	uint8_t mux_flags = 0;
+	google_chromeec_usb_get_pd_mux_info(port, &mux_flags);
+	if ((mux_flags & flag) == flag)
+		return 1;
+	return 0;
+}
+
+int google_chromeec_wait_for_dp_mode_entry(int port, long timeout_ms)
 {
-	uint8_t mux_flags;
 	struct stopwatch sw;
 
 	if (!google_chromeec_check_feature(EC_FEATURE_TYPEC_REQUIRE_AP_MODE_ENTRY)) {
-		google_chromeec_usb_get_pd_mux_info(port, &mux_flags);
-		if (!(mux_flags & USB_PD_MUX_HPD_LVL) || !(mux_flags & USB_PD_MUX_DP_ENABLED)) {
-			printk(BIOS_WARNING, "DP/HPD not ready. Abort.\n");
+		if (!google_chromeec_check_mux_flag(port, USB_PD_MUX_DP_ENABLED)) {
+			printk(BIOS_WARNING, "DP mode entry is not ready. Abort.\n");
 			return -1;
 		}
 
@@ -1399,14 +1413,39 @@ int google_chromeec_wait_for_dp_hpd(int port, long timeout_ms)
 	}
 
 	stopwatch_init_msecs_expire(&sw, timeout_ms);
-	do {
-		google_chromeec_usb_get_pd_mux_info(port, &mux_flags);
+	while (!google_chromeec_check_mux_flag(port, USB_PD_MUX_DP_ENABLED)) {
+		if (stopwatch_expired(&sw)) {
+			printk(BIOS_WARNING, "DP not ready after %ldms. Abort.\n", timeout_ms);
+			return -1;
+		}
+		mdelay(100);
+	}
+	printk(BIOS_INFO, "DP ready after %lld ms\n", stopwatch_duration_msecs(&sw));
+
+	return 0;
+}
+
+int google_chromeec_wait_for_hpd(int port, long timeout_ms)
+{
+	struct stopwatch sw;
+
+	if (!google_chromeec_check_feature(EC_FEATURE_TYPEC_REQUIRE_AP_MODE_ENTRY)) {
+		if (!google_chromeec_check_mux_flag(port, USB_PD_MUX_HPD_LVL)) {
+			printk(BIOS_WARNING, "HPD not ready. Abort.\n");
+			return -1;
+		}
+
+		return 0;
+	}
+
+	stopwatch_init_msecs_expire(&sw, timeout_ms);
+	while (!google_chromeec_check_mux_flag(port, USB_PD_MUX_HPD_LVL)) {
 		if (stopwatch_expired(&sw)) {
 			printk(BIOS_WARNING, "HPD not ready after %ldms. Abort.\n", timeout_ms);
 			return -1;
 		}
 		mdelay(100);
-	} while (!(mux_flags & USB_PD_MUX_HPD_LVL) || !(mux_flags & USB_PD_MUX_DP_ENABLED));
+	}
 	printk(BIOS_INFO, "HPD ready after %lld ms\n", stopwatch_duration_msecs(&sw));
 
 	return 0;
diff --git a/src/ec/google/chromeec/ec.h b/src/ec/google/chromeec/ec.h
index 42326601e8..61b23cf3ba 100644
--- a/src/ec/google/chromeec/ec.h
+++ b/src/ec/google/chromeec/ec.h
@@ -38,10 +38,14 @@ int google_chromeec_usb_get_pd_mux_info(int port, uint8_t *flags);
  *              >=1: Bitmask of the ports that DP device is connected
  */
 int google_chromeec_wait_for_displayport(long timeout_ms);
+/* Poll (up to `timeout_ms` ms) for the DP mode entry
+ * event on the specified port.
+ * Return: 0 on DP mode entry success, -1 on timeout */
+int google_chromeec_wait_for_dp_mode_entry(int port, long timeout_ms);
 /* Poll (up to `timeout_ms` ms) for a Hot-Plug Detect (HPD)
  * event on the specified port.
  * Return: 0 on HPD ready, -1 on timeout */
-int google_chromeec_wait_for_dp_hpd(int port, long timeout_ms);
+int google_chromeec_wait_for_hpd(int port, long timeout_ms);
 /* Send command to EC to request to enter DisplayPort ALT mode on the
  * specified port.
  * Return: 0 on success, -1 on error */
diff --git a/src/ec/google/chromeec/usbc_mux.c b/src/ec/google/chromeec/usbc_mux.c
index 64195428b0..f89416a898 100644
--- a/src/ec/google/chromeec/usbc_mux.c
+++ b/src/ec/google/chromeec/usbc_mux.c
@@ -9,7 +9,8 @@ static const struct usbc_ops google_chromeec_usbc_ops = {
 	.dp_ops = {
 		.wait_for_connection = google_chromeec_wait_for_displayport,
 		.enter_dp_mode = google_chromeec_typec_control_enter_dp_mode,
-		.wait_for_hpd = google_chromeec_wait_for_dp_hpd,
+		.wait_for_dp_mode_entry = google_chromeec_wait_for_dp_mode_entry,
+		.wait_for_hpd = google_chromeec_wait_for_hpd,
 	},
 };