usb: dwc3: core: add power management support

Add support for basic power management on
the dwc3 driver. While there is still lots
to improve for full PM support, this minimal
patch will already make sure that we survive
suspend-to-ram and suspend-to-disk without
major issues.

Cc: Vikas C Sajjan <vikas.sajjan@linaro.org>
Tested-by: Vivek Gautam <gautam.vivek@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

1 files changed, 118 insertions, 0 deletions

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 47435086058b..75a9f88a5ad6 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -591,6 +591,123 @@ static int dwc3_remove(struct platform_device *pdev)
 	return 0;
 }
 
+#ifdef CONFIG_PM
+static int dwc3_prepare(struct device *dev)
+{
+	struct dwc3	*dwc = dev_get_drvdata(dev);
+	unsigned long	flags;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+
+	switch (dwc->mode) {
+	case DWC3_MODE_DEVICE:
+	case DWC3_MODE_DRD:
+		dwc3_gadget_prepare(dwc);
+		/* FALLTHROUGH */
+	case DWC3_MODE_HOST:
+	default:
+		dwc3_event_buffers_cleanup(dwc);
+		break;
+	}
+
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
+	return 0;
+}
+
+static void dwc3_complete(struct device *dev)
+{
+	struct dwc3	*dwc = dev_get_drvdata(dev);
+	unsigned long	flags;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+
+	switch (dwc->mode) {
+	case DWC3_MODE_DEVICE:
+	case DWC3_MODE_DRD:
+		dwc3_gadget_complete(dwc);
+		/* FALLTHROUGH */
+	case DWC3_MODE_HOST:
+	default:
+		dwc3_event_buffers_setup(dwc);
+		break;
+	}
+
+	spin_unlock_irqrestore(&dwc->lock, flags);
+}
+
+static int dwc3_suspend(struct device *dev)
+{
+	struct dwc3	*dwc = dev_get_drvdata(dev);
+	unsigned long	flags;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+
+	switch (dwc->mode) {
+	case DWC3_MODE_DEVICE:
+	case DWC3_MODE_DRD:
+		dwc3_gadget_suspend(dwc);
+		/* FALLTHROUGH */
+	case DWC3_MODE_HOST:
+	default:
+		/* do nothing */
+		break;
+	}
+
+	dwc->gctl = dwc3_readl(dwc->regs, DWC3_GCTL);
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
+	usb_phy_shutdown(dwc->usb3_phy);
+	usb_phy_shutdown(dwc->usb2_phy);
+
+	return 0;
+}
+
+static int dwc3_resume(struct device *dev)
+{
+	struct dwc3	*dwc = dev_get_drvdata(dev);
+	unsigned long	flags;
+
+	usb_phy_init(dwc->usb3_phy);
+	usb_phy_init(dwc->usb2_phy);
+	msleep(100);
+
+	spin_lock_irqsave(&dwc->lock, flags);
+
+	dwc3_writel(dwc->regs, DWC3_GCTL, dwc->gctl);
+
+	switch (dwc->mode) {
+	case DWC3_MODE_DEVICE:
+	case DWC3_MODE_DRD:
+		dwc3_gadget_resume(dwc);
+		/* FALLTHROUGH */
+	case DWC3_MODE_HOST:
+	default:
+		/* do nothing */
+		break;
+	}
+
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
+	pm_runtime_disable(dev);
+	pm_runtime_set_active(dev);
+	pm_runtime_enable(dev);
+
+	return 0;
+}
+
+static const struct dev_pm_ops dwc3_dev_pm_ops = {
+	.prepare	= dwc3_prepare,
+	.complete	= dwc3_complete,
+
+	SET_SYSTEM_SLEEP_PM_OPS(dwc3_suspend, dwc3_resume)
+};
+
+#define DWC3_PM_OPS	&(dwc3_dev_pm_ops)
+#else
+#define DWC3_PM_OPS	NULL
+#endif
+
 #ifdef CONFIG_OF
 static const struct of_device_id of_dwc3_match[] = {
 	{
@@ -607,6 +724,7 @@ static struct platform_driver dwc3_driver = {
 	.driver		= {
 		.name	= "dwc3",
 		.of_match_table	= of_match_ptr(of_dwc3_match),
+		.pm	= DWC3_PM_OPS,
 	},
 };