From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Date: Thu, 20 Oct 2016 04:19:19 +0000 (+0900)
Subject: usb: renesas_usbhs: add wait after initialization for R-Car Gen3
X-Git-Tag: v4.9-rc3~8^2~1
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=b76032396d7958f006bccf5fb2535beb5526837c;p=karo-tx-linux.git

usb: renesas_usbhs: add wait after initialization for R-Car Gen3

Since the controller on R-Car Gen3 doesn't have any status registers
to detect initialization (LPSTS.SUSPM = 1) and the initialization needs
up to 45 usec, this patch adds wait after the initialization. Otherwise,
writing other registers (e.g. INTENB0) will fail.

Fixes: de18757e272d ("usb: renesas_usbhs: add R-Car Gen3 power control")
Cc: <stable@vger.kernel.org> # v4.6+
Cc: <balbi@kernel.org>
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/usb/renesas_usbhs/rcar3.c b/drivers/usb/renesas_usbhs/rcar3.c
index 1d70add926f0..d544b331c9f2 100644
--- a/drivers/usb/renesas_usbhs/rcar3.c
+++ b/drivers/usb/renesas_usbhs/rcar3.c
@@ -9,6 +9,7 @@
  *
  */
 
+#include <linux/delay.h>
 #include <linux/io.h>
 #include "common.h"
 #include "rcar3.h"
@@ -35,10 +36,13 @@ static int usbhs_rcar3_power_ctrl(struct platform_device *pdev,
 
 	usbhs_write32(priv, UGCTRL2, UGCTRL2_RESERVED_3 | UGCTRL2_USB0SEL_OTG);
 
-	if (enable)
+	if (enable) {
 		usbhs_bset(priv, LPSTS, LPSTS_SUSPM, LPSTS_SUSPM);
-	else
+		/* The controller on R-Car Gen3 needs to wait up to 45 usec */
+		udelay(45);
+	} else {
 		usbhs_bset(priv, LPSTS, LPSTS_SUSPM, 0);
+	}
 
 	return 0;
 }