[1/4,v5] misc: rtsx_usb: Use USB remote wakeup signaling for card insertion detection

[1/4,v5] misc: rtsx_usb: Use USB remote wakeup signaling for card insertion detection

[Kai-Heng Feng]

Although rtsx_usb doesn't support card removal detection, card insertion
will resume rtsx_usb by USB remote wakeup signaling.

When rtsx_usb gets resumed, also resumes its child devices,
rtsx_usb_sdmmc and rtsx_usb_ms, to notify them there's a card in its
slot.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
 drivers/misc/cardreader/rtsx_usb.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/misc/cardreader/rtsx_usb.c b/drivers/misc/cardreader/rtsx_usb.c
index b97903ff1a72..f7a66f614085 100644
--- a/drivers/misc/cardreader/rtsx_usb.c
+++ b/drivers/misc/cardreader/rtsx_usb.c
@@ -723,8 +723,15 @@ static int rtsx_usb_suspend(struct usb_interface *intf, pm_message_t message)
 	return 0;
 }
 
+static int rtsx_usb_resume_child(struct device *dev, void *data)
+{
+	pm_request_resume(dev);
+	return 0;
+}
+
 static int rtsx_usb_resume(struct usb_interface *intf)
 {
+	device_for_each_child(&intf->dev, NULL, rtsx_usb_resume_child);
 	return 0;
 }
 
@@ -734,6 +741,7 @@ static int rtsx_usb_reset_resume(struct usb_interface *intf)
 		(struct rtsx_ucr *)usb_get_intfdata(intf);
 
 	rtsx_usb_reset_chip(ucr);
+	device_for_each_child(&intf->dev, NULL, rtsx_usb_resume_child);
 	return 0;
 }