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: de18757 ("usb: renesas_usbhs: add R-Car Gen3 power control") Cc: <[email protected]> # v4.6+ Cc: <[email protected]> Signed-off-by: Yoshihiro Shimoda <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
dtwlin · Oct 24, 2016 · b760323 · b760323
1 parent ed6d6f8
commit b760323
Showing 1 changed file with 6 additions and 2 deletions.
diff --git 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;
 }