usb: dwc3: omap: add basic suspend/resume support

this patch implements basic suspend/resume
functionality for the OMAP glue layer.

Tested-by: Vivek Gautam <gautam.vivek@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

1 files changed, 56 insertions, 0 deletions

diff --git a/drivers/usb/dwc3/dwc3-omap.c b/drivers/usb/dwc3/dwc3-omap.c
index ed178c0fc426..35b9673b84df 100644
--- a/drivers/usb/dwc3/dwc3-omap.c
+++ b/drivers/usb/dwc3/dwc3-omap.c
@@ -121,6 +121,8 @@ struct dwc3_omap {
         int                     irq;
         void __iomem            *base;
 
+        u32                     utmi_otg_status;
+
         u32                     dma_status:1;
 };
 
@@ -402,12 +404,66 @@ static const struct of_device_id of_dwc3_match[] = {
 };
 MODULE_DEVICE_TABLE(of, of_dwc3_match);
 
+#ifdef CONFIG_PM
+static int dwc3_omap_prepare(struct device *dev)
+{
+        struct dwc3_omap        *omap = dev_get_drvdata(dev);
+
+        dwc3_omap_disable_irqs(omap);
+
+        return 0;
+}
+
+static void dwc3_omap_complete(struct device *dev)
+{
+        struct dwc3_omap        *omap = dev_get_drvdata(dev);
+
+        dwc3_omap_enable_irqs(omap);
+}
+
+static int dwc3_omap_suspend(struct device *dev)
+{
+        struct dwc3_omap        *omap = dev_get_drvdata(dev);
+
+        omap->utmi_otg_status = dwc3_omap_readl(omap->base,
+                        USBOTGSS_UTMI_OTG_STATUS);
+
+        return 0;
+}
+
+static int dwc3_omap_resume(struct device *dev)
+{
+        struct dwc3_omap        *omap = dev_get_drvdata(dev);
+
+        dwc3_omap_writel(omap->base, USBOTGSS_UTMI_OTG_STATUS,
+                        omap->utmi_otg_status);
+
+        pm_runtime_disable(dev);
+        pm_runtime_set_active(dev);
+        pm_runtime_enable(dev);
+
+        return 0;
+}
+
+static const struct dev_pm_ops dwc3_omap_dev_pm_ops = {
+        .prepare        = dwc3_omap_prepare,
+        .complete       = dwc3_omap_complete,
+
+        SET_SYSTEM_SLEEP_PM_OPS(dwc3_omap_suspend, dwc3_omap_resume)
+};
+
+#define DEV_PM_OPS      (&dwc3_omap_dev_pm_ops)
+#else
+#define DEV_PM_OPS      NULL
+#endif /* CONFIG_PM */
+
 static struct platform_driver dwc3_omap_driver = {
         .probe          = dwc3_omap_probe,
         .remove         = dwc3_omap_remove,
         .driver         = {
                 .name   = "omap-dwc3",
                 .of_match_table = of_dwc3_match,
+                .pm     = DEV_PM_OPS,
         },
 };