[PATCH v2] usb: dwc2: gadget: Fix enter to hibernation for UTMI+ PHY

[Minas Harutyunyan <Minas.Harutyunyan@xxxxxxxxxxxx>]

For UTMI+ PHY, according to programming guide, first should be set
PMUACTV bit then STOPPCLK bit. Otherwise, when the device issues
Remote Wakeup, then host notices disconnect instead.
For ULPI PHY, above mentioned bits must be set in reversed order:
STOPPCLK then PMUACTV.

Fixes: 4483ef3c1685 ("usb: dwc2: Add hibernation updates for ULPI PHY")
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Tomasz Mon <tomasz.mon@xxxxxxxxxxxxx>
Signed-off-by: Minas Harutyunyan <Minas.Harutyunyan@xxxxxxxxxxxx>
---
Changes in v2:
 - Added Cc: stable@xxxxxxxxxxxxxxx
---
 drivers/usb/dwc2/gadget.c | 37 +++++++++++++++++++++++++------------
 1 file changed, 25 insertions(+), 12 deletions(-)

diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index e7bf9cc635be..be6b792e9a7d 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -5345,20 +5345,33 @@ int dwc2_gadget_enter_hibernation(struct dwc2_hsotg *hsotg)
        if (gusbcfg & GUSBCFG_ULPI_UTMI_SEL) {
                /* ULPI interface */
                gpwrdn |= GPWRDN_ULPI_LATCH_EN_DURING_HIB_ENTRY;
-       }
-       dwc2_writel(hsotg, gpwrdn, GPWRDN);
-       udelay(10);
+               dwc2_writel(hsotg, gpwrdn, GPWRDN);
+               udelay(10);

-       /* Suspend the Phy Clock */
-       pcgcctl = dwc2_readl(hsotg, PCGCTL);
-       pcgcctl |= PCGCTL_STOPPCLK;
-       dwc2_writel(hsotg, pcgcctl, PCGCTL);
-       udelay(10);
+               pcgcctl = dwc2_readl(hsotg, PCGCTL);
+               pcgcctl |= PCGCTL_STOPPCLK;
+               dwc2_writel(hsotg, pcgcctl, PCGCTL);
+               udelay(10);

-       gpwrdn = dwc2_readl(hsotg, GPWRDN);
-       gpwrdn |= GPWRDN_PMUACTV;
-       dwc2_writel(hsotg, gpwrdn, GPWRDN);
-       udelay(10);
+               gpwrdn = dwc2_readl(hsotg, GPWRDN);
+               gpwrdn |= GPWRDN_PMUACTV;
+               dwc2_writel(hsotg, gpwrdn, GPWRDN);
+               udelay(10);
+       } else {
+               /* UTMI+ Interface */
+               dwc2_writel(hsotg, gpwrdn, GPWRDN);
+               udelay(10);
+
+               gpwrdn = dwc2_readl(hsotg, GPWRDN);
+               gpwrdn |= GPWRDN_PMUACTV;
+               dwc2_writel(hsotg, gpwrdn, GPWRDN);
+               udelay(10);
+
+               pcgcctl = dwc2_readl(hsotg, PCGCTL);
+               pcgcctl |= PCGCTL_STOPPCLK;
+               dwc2_writel(hsotg, pcgcctl, PCGCTL);
+               udelay(10);
+       }

        /* Set flag to indicate that we are in hibernation */
        hsotg->hibernated = 1;

base-commit: 12393996c1b28cd944465d2f55500ca84399a7f1
--
2.41.0