usb: host: ehci-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>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://patch.msgid.link/20251106143625.3050119-3-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
index 57d5a7ddac5f0133bdd206f95a7e15468cba8a17..f61f095cedabbe8b95bbc232b9af4ef758dac9ac 100644 (file)
--- a/drivers/usb/host/ehci-platform.c
+++ b/drivers/usb/host/ehci-platform.c
@@ -454,6 +454,17 @@ static int __maybe_unused ehci_platform_suspend(struct device *dev)
        if (pdata->power_suspend)
                pdata->power_suspend(pdev);
 
+       ret = reset_control_assert(priv->rsts);
+       if (ret) {
+               if (pdata->power_on)
+                       pdata->power_on(pdev);
+
+               ehci_resume(hcd, false);
+
+               if (priv->quirk_poll)
+                       quirk_poll_init(priv);
+       }
+
        return ret;
 }
 
@@ -464,11 +475,18 @@ static int __maybe_unused ehci_platform_resume(struct device *dev)
        struct platform_device *pdev = to_platform_device(dev);
        struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
        struct device *companion_dev;
+       int err;
+
+       err = reset_control_deassert(priv->rsts);
+       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->rsts);
                        return err;
+               }
        }
 
        companion_dev = usb_of_get_companion_dev(hcd->self.controller);