usb: host: ohci-platform: Call reset assert/deassert on suspend/resume

The Renesas RZ/G3S SoC supports a power-saving mode in which power to most
of the SoC components is turned off, including the USB blocks. On the
resume path, the reset signal must be de-asserted before applying any
settings to the USB registers. To handle this properly, call
reset_control_assert() and reset_control_deassert() during suspend and
resume, respectively.

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Link: https://patch.msgid.link/20251106143625.3050119-4-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/ohci-platform.c b/drivers/usb/host/ohci-platform.c
index af26f1449bc2e8097fffdc6b53b6551dde3fa331..2e4bb5cc2165f2e9ea56ea866ac5523997355ae3 100644 (file)
--- a/drivers/usb/host/ohci-platform.c
+++ b/drivers/usb/host/ohci-platform.c
@@ -270,6 +270,7 @@ static int ohci_platform_suspend(struct device *dev)
        struct usb_hcd *hcd = dev_get_drvdata(dev);
        struct usb_ohci_pdata *pdata = dev->platform_data;
        struct platform_device *pdev = to_platform_device(dev);
+       struct ohci_platform_priv *priv = hcd_to_ohci_priv(hcd);
        bool do_wakeup = device_may_wakeup(dev);
        int ret;
 
@@ -280,6 +281,14 @@ static int ohci_platform_suspend(struct device *dev)
        if (pdata->power_suspend)
                pdata->power_suspend(pdev);
 
+       ret = reset_control_assert(priv->resets);
+       if (ret) {
+               if (pdata->power_on)
+                       pdata->power_on(pdev);
+
+               ohci_resume(hcd, false);
+       }
+
        return ret;
 }
 
@@ -288,11 +297,19 @@ static int ohci_platform_resume_common(struct device *dev, bool hibernated)
        struct usb_hcd *hcd = dev_get_drvdata(dev);
        struct usb_ohci_pdata *pdata = dev_get_platdata(dev);
        struct platform_device *pdev = to_platform_device(dev);
+       struct ohci_platform_priv *priv = hcd_to_ohci_priv(hcd);
+       int err;
+
+       err = reset_control_deassert(priv->resets);
+       if (err)
+               return err;
 
        if (pdata->power_on) {
-               int err = pdata->power_on(pdev);
-               if (err < 0)
+               err = pdata->power_on(pdev);
+               if (err < 0) {
+                       reset_control_assert(priv->resets);
                        return err;
+               }
        }
 
        ohci_resume(hcd, hibernated);