usb: musb: fix runtime PM in debugfs

MUSB driver now has runtime PM support, but the debugfs driver misses
the PM _get/_put() calls, which could cause MUSB register access
failure.

Cc: stable@vger.kernel.org # 4.9+
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/musb/musb_debugfs.c

@@ -114,6 +114,7 @@ static int musb_regdump_show(struct seq_file *s, void *unused)
 	unsigned		i;
 
 	seq_printf(s, "MUSB (M)HDRC Register Dump\n");
+	pm_runtime_get_sync(musb->controller);
 
 	for (i = 0; i < ARRAY_SIZE(musb_regmap); i++) {
 		switch (musb_regmap[i].size) {
@@ -132,6 +133,8 @@ static int musb_regdump_show(struct seq_file *s, void *unused)
 		}
 	}
 
+	pm_runtime_mark_last_busy(musb->controller);
+	pm_runtime_put_autosuspend(musb->controller);
 	return 0;
 }
 
@@ -145,7 +148,10 @@ static int musb_test_mode_show(struct seq_file *s, void *unused)
 	struct musb		*musb = s->private;
 	unsigned		test;
 
+	pm_runtime_get_sync(musb->controller);
 	test = musb_readb(musb->mregs, MUSB_TESTMODE);
+	pm_runtime_mark_last_busy(musb->controller);
+	pm_runtime_put_autosuspend(musb->controller);
 
 	if (test & MUSB_TEST_FORCE_HOST)
 		seq_printf(s, "force host\n");
@@ -194,11 +200,12 @@ static ssize_t musb_test_mode_write(struct file *file,
 	u8			test;
 	char			buf[18];
 
+	pm_runtime_get_sync(musb->controller);
 	test = musb_readb(musb->mregs, MUSB_TESTMODE);
 	if (test) {
 		dev_err(musb->controller, "Error: test mode is already set. "
 			"Please do USB Bus Reset to start a new test.\n");
-		return count;
+		goto ret;
 	}
 
 	memset(buf, 0x00, sizeof(buf));
@@ -234,6 +241,9 @@ static ssize_t musb_test_mode_write(struct file *file,
 
 	musb_writeb(musb->mregs, MUSB_TESTMODE, test);
 
+ret:
+	pm_runtime_mark_last_busy(musb->controller);
+	pm_runtime_put_autosuspend(musb->controller);
 	return count;
 }
 
@@ -254,8 +264,13 @@ static int musb_softconnect_show(struct seq_file *s, void *unused)
 	switch (musb->xceiv->otg->state) {
 	case OTG_STATE_A_HOST:
 	case OTG_STATE_A_WAIT_BCON:
+		pm_runtime_get_sync(musb->controller);
+
 		reg = musb_readb(musb->mregs, MUSB_DEVCTL);
 		connect = reg & MUSB_DEVCTL_SESSION ? 1 : 0;
+
+		pm_runtime_mark_last_busy(musb->controller);
+		pm_runtime_put_autosuspend(musb->controller);
 		break;
 	default:
 		connect = -1;
@@ -284,6 +299,7 @@ static ssize_t musb_softconnect_write(struct file *file,
 	if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
 		return -EFAULT;
 
+	pm_runtime_get_sync(musb->controller);
 	if (!strncmp(buf, "0", 1)) {
 		switch (musb->xceiv->otg->state) {
 		case OTG_STATE_A_HOST:
@@ -314,6 +330,8 @@ static ssize_t musb_softconnect_write(struct file *file,
 		}
 	}
 
+	pm_runtime_mark_last_busy(musb->controller);
+	pm_runtime_put_autosuspend(musb->controller);
 	return count;
 }