usb: chipidea: Only read/write OTGSC from one place

With the id and vbus detection done via extcon we need to make
sure we poll the status of OTGSC properly by considering what the
extcon is saying, and not just what the register is saying. Let's
move this hw_wait_reg() function to the only place it's used and
simplify it for polling the OTGSC register. Then we can make
certain we only use the hw_read_otgsc() API to read OTGSC, which
will make sure we properly handle extcon events.

Acked-by: Peter Chen <peter.chen@nxp.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Ivan T. Ivanov" <iivanov.xz@gmail.com>
Fixes: 3ecb3e09b042 ("usb: chipidea: Use extcon framework for VBUS and ID detect")
Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: Peter Chen <peter.chen@nxp.com>

1 files changed, 30 insertions, 4 deletions

diff --git a/drivers/usb/chipidea/otg.c b/drivers/usb/chipidea/otg.c
index 03b6743461d1..a829607c3e4d 100644
--- a/drivers/usb/chipidea/otg.c
+++ b/drivers/usb/chipidea/otg.c
@@ -104,7 +104,31 @@ void ci_handle_vbus_change(struct ci_hdrc *ci)
 		usb_gadget_vbus_disconnect(&ci->gadget);
 }
 
-#define CI_VBUS_STABLE_TIMEOUT_MS 5000
+/**
+ * When we switch to device mode, the vbus value should be lower
+ * than OTGSC_BSV before connecting to host.
+ *
+ * @ci: the controller
+ *
+ * This function returns an error code if timeout
+ */
+static int hw_wait_vbus_lower_bsv(struct ci_hdrc *ci)
+{
+	unsigned long elapse = jiffies + msecs_to_jiffies(5000);
+	u32 mask = OTGSC_BSV;
+
+	while (hw_read_otgsc(ci, mask)) {
+		if (time_after(jiffies, elapse)) {
+			dev_err(ci->dev, "timeout waiting for %08x in OTGSC\n",
+					mask);
+			return -ETIMEDOUT;
+		}
+		msleep(20);
+	}
+
+	return 0;
+}
+
 static void ci_handle_id_switch(struct ci_hdrc *ci)
 {
 	enum ci_role role = ci_otg_role(ci);
@@ -116,9 +140,11 @@ static void ci_handle_id_switch(struct ci_hdrc *ci)
 		ci_role_stop(ci);
 
 		if (role == CI_ROLE_GADGET)
-			/* wait vbus lower than OTGSC_BSV */
-			hw_wait_reg(ci, OP_OTGSC, OTGSC_BSV, 0,
-					CI_VBUS_STABLE_TIMEOUT_MS);
+			/*
+			 * wait vbus lower than OTGSC_BSV before connecting
+			 * to host
+			 */
+			hw_wait_vbus_lower_bsv(ci);
 
 		ci_role_start(ci, role);
 	}