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: 3ecb3e09 ("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>

drivers/usb/chipidea/ci.h

@@ -428,9 +428,6 @@ int hw_port_test_set(struct ci_hdrc *ci, u8 mode);
 
 u8 hw_port_test_get(struct ci_hdrc *ci);
 
-int hw_wait_reg(struct ci_hdrc *ci, enum ci_hw_regs reg, u32 mask,
-				u32 value, unsigned int timeout_ms);
-
 void ci_platform_configure(struct ci_hdrc *ci);
 
 int dbg_create_files(struct ci_hdrc *ci);

drivers/usb/chipidea/core.c

@@ -516,38 +516,6 @@ int hw_device_reset(struct ci_hdrc *ci)
 	return 0;
 }
 
-/**
- * hw_wait_reg: wait the register value
- *
- * Sometimes, it needs to wait register value before going on.
- * Eg, when switch to device mode, the vbus value should be lower
- * than OTGSC_BSV before connects to host.
- *
- * @ci: the controller
- * @reg: register index
- * @mask: mast bit
- * @value: the bit value to wait
- * @timeout_ms: timeout in millisecond
- *
- * This function returns an error code if timeout
- */
-int hw_wait_reg(struct ci_hdrc *ci, enum ci_hw_regs reg, u32 mask,
-				u32 value, unsigned int timeout_ms)
-{
-	unsigned long elapse = jiffies + msecs_to_jiffies(timeout_ms);
-
-	while (hw_read(ci, reg, mask) != value) {
-		if (time_after(jiffies, elapse)) {
-			dev_err(ci->dev, "timeout waiting for %08x in %d\n",
-					mask, reg);
-			return -ETIMEDOUT;
-		}
-		msleep(20);
-	}
-
-	return 0;
-}
-
 static irqreturn_t ci_irq(int irq, void *data)
 {
 	struct ci_hdrc *ci = data;

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);
 	}