ENGR00325832 usb: chipidea: usb vbus glitch check logic change

This patch changes the vbus glitch check to cover usb otg certification
case, so the possible cases of vbus rise:
- USB vbus can reach AVV(4.4v), valid vbus.
- USB vbus keeps above BSV(0.8v) but lower than AVV(4.4v) for
  more than 300ms, we think it's valid vbus event, this can meet
  usb otg certificataion case(B device can do connection in 1s when
  vbus is 4.0v).
- USB vbus cannot be kept above BSV(0.8v) for more than 300ms,
  it's a vbus glitch.
In case of vbus drop: if the vbus on flag is not set, it's a vbus glitch,
otherwise it's a valid vbus drop event.

Acked-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Li Jun <b47624@freescale.com>
(cherry picked from commit de5ab444839b6d1492d697256ea2b8a1dcaffc62)

2 files changed, 22 insertions, 17 deletions

diff --git a/drivers/usb/chipidea/otg.c b/drivers/usb/chipidea/otg.c
index 7b9e417060e8..1850b034a4e5 100644
--- a/drivers/usb/chipidea/otg.c
+++ b/drivers/usb/chipidea/otg.c
@@ -57,22 +57,26 @@ enum ci_role ci_otg_role(struct ci_hdrc *ci)
 	return role;
 }
 
-#define CI_VBUS_CONNECT_TIMEOUT_MS 500
+/*
+ * Handling vbus glitch
+ * We only need to consider glitch for without usb connection,
+ * With usb connection, we consider it as real disconnection.
+ *
+ * If the vbus can't be kept above B session valid for timeout value,
+ * we think it is a vbus glitch, otherwise it's a valid vbus.
+ */
+#define CI_VBUS_CONNECT_TIMEOUT_MS 300
 static int ci_is_vbus_glitch(struct ci_hdrc *ci)
 {
-	/*
-	 * Handling vbus glitch
-	 *
-	 * We only need to consider glitch for without usb connection,
-	 * With usb connection, we consider it as real disconnection.
-	 *
-	 * If the vbus can't higher than AVV in timeout value, we think
-	 * it is a vbus glitch
-	 */
-	if (hw_wait_reg(ci, OP_OTGSC, OTGSC_AVV, OTGSC_AVV,
-			CI_VBUS_CONNECT_TIMEOUT_MS)) {
-		dev_warn(ci->dev, "there is a vbus glitch\n");
-		return 1;
+	int i;
+	for (i = 0; i < CI_VBUS_CONNECT_TIMEOUT_MS/20; i++) {
+		if (hw_read_otgsc(ci, OTGSC_AVV)) {
+			return 0;
+		} else if (!hw_read_otgsc(ci, OTGSC_BSV)) {
+			dev_warn(ci->dev, "there is a vbus glitch\n");
+			return 1;
+		}
+		msleep(20);
 	}
 
 	return 0;
@@ -141,8 +145,7 @@ static void ci_handle_vbus_glitch(struct ci_hdrc *ci)
 			valid_vbus_change = true;
 		}
 	} else {
-		if (ci->vbus_active || (ci_otg_is_fsm_mode(ci) &&
-						ci->fsm.b_sess_vld))
+		if (ci->vbus_active && !ci_otg_is_fsm_mode(ci))
 			valid_vbus_change = true;
 	}
 
diff --git a/drivers/usb/chipidea/otg_fsm.c b/drivers/usb/chipidea/otg_fsm.c
index 34a4f3c53a61..7aa33e588f11 100644
--- a/drivers/usb/chipidea/otg_fsm.c
+++ b/drivers/usb/chipidea/otg_fsm.c
@@ -807,13 +807,15 @@ irqreturn_t ci_otg_fsm_irq(struct ci_hdrc *ci)
 			}
 		} else if (otg_int_src & OTGSC_BSVIS) {
 			hw_write_otgsc(ci, OTGSC_BSVIS, OTGSC_BSVIS);
-			ci->vbus_glitch_check_event = true;
 			if (!(otgsc & OTGSC_BSV) && fsm->b_sess_vld) {
+				ci->b_sess_valid_event = true;
 				fsm->b_sess_vld = 0;
 				if (fsm->id)
 					ci_otg_add_timer(ci, B_SSEND_SRP);
 				if (fsm->b_bus_req)
 					fsm->b_bus_req = 0;
+			} else {
+				ci->vbus_glitch_check_event = true;
 			}
 		} else if (otg_int_src & OTGSC_AVVIS) {
 			hw_write_otgsc(ci, OTGSC_AVVIS, OTGSC_AVVIS);