[PATCH 4.19 08/79] phy: renesas: rcar-gen3-usb2: Disable clearing VBUS in over-current

Greg Kroah-Hartman
2019-09-19T22:32:19Z

From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

commit e6839c31a608e79f2057fab987dd814f5d3477e6 upstream.

The hardware manual should be revised, but the initial value of
VBCTRL.OCCLREN is set to 1 actually. If the bit is set, the hardware
clears VBCTRL.VBOUT and ADPCTRL.DRVVBUS registers automatically
when the hardware detects over-current signal from a USB power switch.
However, since the hardware doesn't have any registers which
indicates over-current, the driver cannot handle it at all. So, if
"is_otg_channel" hardware detects over-current, since ADPCTRL.DRVVBUS
register is cleared automatically, the channel cannot be used after
that.

To resolve this behavior, this patch sets the VBCTRL.OCCLREN to 0
to keep ADPCTRL.DRVVBUS even if the "is_otg_channel" hardware
detects over-current. (We assume a USB power switch itself protects
over-current and turns the VBUS off.)

This patch is inspired by a BSP patch from Kazuya Mizuguchi.

Fixes: 1114e2d31731 ("phy: rcar-gen3-usb2: change the mode to OTG on the combined channel")
Cc: <stable@vger.kernel.org> # v4.5+
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/phy/renesas/phy-rcar-gen3-usb2.c | 2 ++
1 file changed, 2 insertions(+)

--- a/drivers/phy/renesas/phy-rcar-gen3-usb2.c
+++ b/drivers/phy/renesas/phy-rcar-gen3-usb2.c
@@ -66,6 +66,7 @@
USB2_OBINT_IDDIGCHG)

/* VBCTRL */
+#define USB2_VBCTRL_OCCLREN BIT(16)
#define USB2_VBCTRL_DRVVBUSSEL BIT(8)

/* LINECTRL1 */
@@ -289,6 +290,7 @@ static void rcar_gen3_init_otg(struct rc
u32 val;

val = readl(usb2_base + USB2_VBCTRL);
+ val &= ~USB2_VBCTRL_OCCLREN;
writel(val | USB2_VBCTRL_DRVVBUSSEL, usb2_base + USB2_VBCTRL);
writel(USB2_OBINT_BITS, usb2_base + USB2_OBINTSTA);
val = readl(usb2_base + USB2_OBINTEN);