ENGR00320099 usb: chipidea: add vbus glitch handling

We add vbus glitch handling for both BSV rise and drop interruptes.
If it is a vbus glitch (higher than BSV but cannot reach AVV), ignore it.

Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Li Jun <b47624@freescale.com>
(cherry picked from commit 827f2fe71e6222882930db7e89460087cb3bce5b)

4 files changed, 63 insertions, 9 deletions

diff --git a/drivers/usb/chipidea/ci.h b/drivers/usb/chipidea/ci.h
index c20edf83aa0f..8d2b74ad36cb 100644
--- a/drivers/usb/chipidea/ci.h
+++ b/drivers/usb/chipidea/ci.h
@@ -194,6 +194,7 @@ struct hw_bank {
  * @debugfs: root dentry for this controller in debugfs
  * @id_event: indicates there is an id event, and handled at ci_otg_work
  * @b_sess_valid_event: indicates there is a vbus event, and handled
+ * @vbus_glitch_check_event: check if vbus change is a glitch
  * at ci_otg_work
  * @imx28_write_fix: Freescale imx28 needs swp instruction for writing
  * @supports_runtime_pm: if runtime pm is supported
@@ -243,6 +244,7 @@ struct ci_hdrc {
 	struct dentry			*debugfs;
 	bool				id_event;
 	bool				b_sess_valid_event;
+	bool				vbus_glitch_check_event;
 	bool				imx28_write_fix;
 	bool				supports_runtime_pm;
 	bool				in_lpm;
diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c
index bcc111a5dfe4..db558402add9 100644
--- a/drivers/usb/chipidea/core.c
+++ b/drivers/usb/chipidea/core.c
@@ -578,7 +578,7 @@ static irqreturn_t ci_irq(int irq, void *data)
 	 * and disconnection events.
 	 */
 	if (ci->is_otg && (otgsc & OTGSC_BSVIE) && (otgsc & OTGSC_BSVIS)) {
-		ci->b_sess_valid_event = true;
+		ci->vbus_glitch_check_event = true;
 		/* Clear BSV irq */
 		hw_write_otgsc(ci, OTGSC_BSVIS, OTGSC_BSVIS);
 		ci_otg_queue_work(ci);
diff --git a/drivers/usb/chipidea/otg.c b/drivers/usb/chipidea/otg.c
index f0b260428bc9..7b9e417060e8 100644
--- a/drivers/usb/chipidea/otg.c
+++ b/drivers/usb/chipidea/otg.c
@@ -57,6 +57,27 @@ enum ci_role ci_otg_role(struct ci_hdrc *ci)
 	return role;
 }
 
+#define CI_VBUS_CONNECT_TIMEOUT_MS 500
+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;
+	}
+
+	return 0;
+}
+
 void ci_handle_vbus_connected(struct ci_hdrc *ci)
 {
 	/*
@@ -67,7 +88,7 @@ void ci_handle_vbus_connected(struct ci_hdrc *ci)
 	if (!ci->is_otg)
 		return;
 
-	if (hw_read_otgsc(ci, OTGSC_BSV))
+	if (hw_read_otgsc(ci, OTGSC_BSV) && !ci_is_vbus_glitch(ci))
 		usb_gadget_vbus_connect(&ci->gadget);
 }
 
@@ -104,6 +125,33 @@ void ci_handle_id_switch(struct ci_hdrc *ci)
 		ci_role_start(ci, role);
 	}
 }
+
+static void ci_handle_vbus_glitch(struct ci_hdrc *ci)
+{
+	bool valid_vbus_change = false;
+
+	if (hw_read_otgsc(ci, OTGSC_BSV)) {
+		if (!ci_is_vbus_glitch(ci)) {
+			if (ci_otg_is_fsm_mode(ci)) {
+				ci->fsm.b_sess_vld = 1;
+				ci->fsm.b_ssend_srp = 0;
+				otg_del_timer(&ci->fsm, B_SSEND_SRP);
+				otg_del_timer(&ci->fsm, B_SRP_FAIL);
+			}
+			valid_vbus_change = true;
+		}
+	} else {
+		if (ci->vbus_active || (ci_otg_is_fsm_mode(ci) &&
+						ci->fsm.b_sess_vld))
+			valid_vbus_change = true;
+	}
+
+	if (valid_vbus_change) {
+		ci->b_sess_valid_event = true;
+		ci_otg_queue_work(ci);
+	}
+}
+
 /**
  * ci_otg_work - perform otg (vbus/id) event handle
  * @work: work struct
@@ -112,6 +160,15 @@ static void ci_otg_work(struct work_struct *work)
 {
 	struct ci_hdrc *ci = container_of(work, struct ci_hdrc, work);
 
+	if (ci->vbus_glitch_check_event) {
+		ci->vbus_glitch_check_event = false;
+		pm_runtime_get_sync(ci->dev);
+		ci_handle_vbus_glitch(ci);
+		pm_runtime_put_sync(ci->dev);
+		enable_irq(ci->irq);
+		return;
+	}
+
 	if (ci_otg_is_fsm_mode(ci) && !ci_otg_fsm_work(ci)) {
 		enable_irq(ci->irq);
 		return;
diff --git a/drivers/usb/chipidea/otg_fsm.c b/drivers/usb/chipidea/otg_fsm.c
index 7ae4d0269d2d..34a4f3c53a61 100644
--- a/drivers/usb/chipidea/otg_fsm.c
+++ b/drivers/usb/chipidea/otg_fsm.c
@@ -807,13 +807,8 @@ 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->b_sess_valid_event = true;
-			if (otgsc & OTGSC_BSV) {
-				fsm->b_sess_vld = 1;
-				ci_otg_del_timer(ci, B_SSEND_SRP);
-				ci_otg_del_timer(ci, B_SRP_FAIL);
-				fsm->b_ssend_srp = 0;
-			} else {
+			ci->vbus_glitch_check_event = true;
+			if (!(otgsc & OTGSC_BSV) && fsm->b_sess_vld) {
 				fsm->b_sess_vld = 0;
 				if (fsm->id)
 					ci_otg_add_timer(ci, B_SSEND_SRP);