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 --- This patch might be difficult to backport to v4.9 or older because the v4.13 added vendor specific directories by commit 0b56e9a7e835 ("phy: Group vendor specific phy drivers").
drivers/phy/renesas/phy-rcar-gen3-usb2.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/phy/renesas/phy-rcar-gen3-usb2.c b/drivers/phy/renesas/phy-rcar-gen3-usb2.c index 8ffba67..b7f6b13 100644 --- a/drivers/phy/renesas/phy-rcar-gen3-usb2.c +++ b/drivers/phy/renesas/phy-rcar-gen3-usb2.c @@ -61,6 +61,7 @@ USB2_OBINT_IDDIGCHG)
/* VBCTRL */ +#define USB2_VBCTRL_OCCLREN BIT(16) #define USB2_VBCTRL_DRVVBUSSEL BIT(8)
/* LINECTRL1 */ @@ -374,6 +375,7 @@ static void rcar_gen3_init_otg(struct rcar_gen3_chan *ch) writel(val, usb2_base + USB2_LINECTRL1);
val = readl(usb2_base + USB2_VBCTRL); + val &= ~USB2_VBCTRL_OCCLREN; writel(val | USB2_VBCTRL_DRVVBUSSEL, usb2_base + USB2_VBCTRL); val = readl(usb2_base + USB2_ADPCTRL); writel(val | USB2_ADPCTRL_IDPULLUP, usb2_base + USB2_ADPCTRL);