usb: mtu3: support suspend/resume for device mode

Support suspend/resume for device mode if the device is not
connected with a host, otherwise reject to suspend.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/1626340078-29111-13-git-send-email-chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 66 insertions, 2 deletions

diff --git a/drivers/usb/mtu3/mtu3_core.c b/drivers/usb/mtu3/mtu3_core.c
index 648e970d77ba..a800920d38b9 100644
--- a/drivers/usb/mtu3/mtu3_core.c
+++ b/drivers/usb/mtu3/mtu3_core.c
@@ -9,6 +9,7 @@
  */
 
 #include <linux/dma-mapping.h>
+#include <linux/iopoll.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of_address.h>
@@ -380,6 +381,24 @@ void mtu3_stop(struct mtu3 *mtu)
 	mtu3_dev_power_down(mtu);
 }
 
+static void mtu3_dev_suspend(struct mtu3 *mtu)
+{
+	if (!mtu->is_active)
+		return;
+
+	mtu3_intr_disable(mtu);
+	mtu3_dev_power_down(mtu);
+}
+
+static void mtu3_dev_resume(struct mtu3 *mtu)
+{
+	if (!mtu->is_active)
+		return;
+
+	mtu3_dev_power_on(mtu);
+	mtu3_intr_enable(mtu);
+}
+
 /* for non-ep0 */
 int mtu3_config_ep(struct mtu3 *mtu, struct mtu3_ep *mep,
 			int interval, int burst, int mult)
@@ -700,11 +719,15 @@ static irqreturn_t mtu3_link_isr(struct mtu3 *mtu)
 	mtu->g.speed = udev_speed;
 	mtu->g.ep0->maxpacket = maxpkt;
 	mtu->ep0_state = MU3D_EP0_STATE_SETUP;
+	mtu->connected = !!(udev_speed != USB_SPEED_UNKNOWN);
 
-	if (udev_speed == USB_SPEED_UNKNOWN)
+	if (udev_speed == USB_SPEED_UNKNOWN) {
 		mtu3_gadget_disconnect(mtu);
-	else
+		pm_runtime_put(mtu->dev);
+	} else {
+		pm_runtime_get(mtu->dev);
 		mtu3_ep0_setup(mtu);
+	}
 
 	return IRQ_HANDLED;
 }
@@ -984,3 +1007,44 @@ void ssusb_gadget_exit(struct ssusb_mtk *ssusb)
 	device_init_wakeup(ssusb->dev, false);
 	mtu3_hw_exit(mtu);
 }
+
+int ssusb_gadget_suspend(struct ssusb_mtk *ssusb, pm_message_t msg)
+{
+	struct mtu3 *mtu = ssusb->u3d;
+	void __iomem *ibase = mtu->ippc_base;
+	u32 value;
+	int ret = 0;
+
+	if (!mtu->gadget_driver)
+		return 0;
+
+	if (mtu->connected)
+		return -EBUSY;
+
+	mtu3_dev_suspend(mtu);
+	synchronize_irq(mtu->irq);
+
+	/* wait for ip to sleep */
+	if (mtu->is_active && mtu->softconnect) {
+		ret = readl_poll_timeout(ibase + U3D_SSUSB_IP_PW_STS1,
+				value, (value & SSUSB_IP_SLEEP_STS), 100, 100000);
+		if (ret) {
+			dev_err(mtu->dev, "ip sleep failed!!!\n");
+			ret = -EBUSY;
+		}
+	}
+
+	return ret;
+}
+
+int ssusb_gadget_resume(struct ssusb_mtk *ssusb, pm_message_t msg)
+{
+	struct mtu3 *mtu = ssusb->u3d;
+
+	if (!mtu->gadget_driver)
+		return 0;
+
+	mtu3_dev_resume(mtu);
+
+	return 0;
+}