[PATCH] usb: xilinx: Add suspend resume support

* [PATCH] usb: xilinx: Add suspend resume support
@ 2021-10-05 11:10 Shubhrajyoti Datta
  2021-10-05 12:20 ` Felipe Balbi
  2021-10-05 14:17 ` kernel test robot
  0 siblings, 2 replies; 3+ messages in thread
From: Shubhrajyoti Datta @ 2021-10-05 11:10 UTC (permalink / raw)
  To: linux-usb
  Cc: balbi, gregkh, michal.simek, shubhrajyoti.datta, git-dev,
	Shubhrajyoti Datta

Add suspend resume support. In the suspend udc is disconnected
and it is set to ready at resume for it to be functional.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
---
 drivers/usb/gadget/udc/udc-xilinx.c | 52 +++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

diff --git a/drivers/usb/gadget/udc/udc-xilinx.c b/drivers/usb/gadget/udc/udc-xilinx.c
index f5ca670776a3..1369792f195a 100644
--- a/drivers/usb/gadget/udc/udc-xilinx.c
+++ b/drivers/usb/gadget/udc/udc-xilinx.c
@@ -2176,6 +2176,57 @@ static int xudc_remove(struct platform_device *pdev)
 	return 0;
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int xudc_suspend(struct device *dev)
+{
+	struct xusb_udc *udc;
+	u32 crtlreg;
+	unsigned long flags;
+
+	udc = dev_get_drvdata(dev);
+
+	spin_lock_irqsave(&udc->lock, flags);
+
+	crtlreg = udc->read_fn(udc->addr + XUSB_CONTROL_OFFSET);
+	crtlreg &= ~XUSB_CONTROL_USB_READY_MASK;
+
+	udc->write_fn(udc->addr, XUSB_CONTROL_OFFSET, crtlreg);
+
+	spin_unlock_irqrestore(&udc->lock, flags);
+	if (udc->driver && udc->driver->disconnect)
+		udc->driver->disconnect(&udc->gadget);
+
+	clk_disable(udc->clk);
+
+	return 0;
+}
+
+static int xudc_resume(struct device *dev)
+{
+	struct xusb_udc *udc;
+	u32 crtlreg;
+	unsigned long flags;
+
+	udc = dev_get_drvdata(dev);
+
+	clk_enable(udc->clk);
+	spin_lock_irqsave(&udc->lock, flags);
+
+	crtlreg = udc->read_fn(udc->addr + XUSB_CONTROL_OFFSET);
+	crtlreg |= XUSB_CONTROL_USB_READY_MASK;
+
+	udc->write_fn(udc->addr, XUSB_CONTROL_OFFSET, crtlreg);
+
+	spin_unlock_irqrestore(&udc->lock, flags);
+
+	return 0;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+static const struct dev_pm_ops xudc_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(xudc_suspend, xudc_resume)
+};
+
 /* Match table for of_platform binding */
 static const struct of_device_id usb_of_match[] = {
 	{ .compatible = "xlnx,usb2-device-4.00.a", },
@@ -2187,6 +2238,7 @@ static struct platform_driver xudc_driver = {
 	.driver = {
 		.name = driver_name,
 		.of_match_table = usb_of_match,
+		.pm	= &xudc_pm_ops,
 	},
 	.probe = xudc_probe,
 	.remove = xudc_remove,
-- 
2.25.1


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