[PATCH v2 1/2] usb: core: add hooks for usb suspend and resume

Puma Hsu
2022-12-14T08:15:50Z

Add the hooks that designer can design and bypass the original
suspend/resume. When the handled is set, skip the original
suspend/resume process.

In mobile, a co-processor can be used for USB audio. When the co-processor
is working for USB audio, the co-processor is the user/owner of the USB
driver, and the ACPU is able to sleep in such condition to improve power
consumption. In original process, the ACPU will suspend/resume until the
USB suspend/resume. We add the hooks, so we can control USB suspend/resume
without affecting the ACPU.

Signed-off-by: Puma Hsu <pumahsu@google.com>

---
Changes in v2:
- Remove the wrong input in the Makefile
- Change description in commit message

---
drivers/usb/core/driver.c | 36 ++++++++++++++++++++++++++++++++++++
drivers/usb/core/usb.h | 5 +++++
2 files changed, 41 insertions(+)

diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index 7e7e119c253f..3d2cfb6c2277 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -35,6 +35,25 @@
#include "usb.h"

+static struct usb_device_vendor_ops *usb_dev_vendor_ops;
+
+int usb_dev_register_vendor_ops(struct usb_device_vendor_ops *vendor_ops)
+{
+ if (vendor_ops == NULL)
+ return -EINVAL;
+
+ usb_dev_vendor_ops = vendor_ops;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(usb_dev_register_vendor_ops);
+
+struct usb_device_vendor_ops *usb_vendor_get_ops(void)
+{
+ return usb_dev_vendor_ops;
+}
+EXPORT_SYMBOL_GPL(usb_vendor_get_ops);
+
+
/*
* Adds a new dynamic USBdevice ID to this driver,
* and cause the driver to probe for all devices again.
@@ -1400,11 +1419,19 @@ static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
int status = 0;
int i = 0, n = 0;
struct usb_interface *intf;
+ bool handled;
+ struct usb_device_vendor_ops *ops = usb_vendor_get_ops();

if (udev->state == USB_STATE_NOTATTACHED ||
udev->state == USB_STATE_SUSPENDED)
goto done;

+ if (ops && ops->usb_dev_suspend) {
+ handled = ops->usb_dev_suspend(udev, msg);
+ if (handled)
+ goto done;
+ }
+
/* Suspend all the interfaces and then udev itself */
if (udev->actconfig) {
n = udev->actconfig->desc.bNumInterfaces;
@@ -1501,11 +1528,20 @@ static int usb_resume_both(struct usb_device *udev, pm_message_t msg)
int status = 0;
int i;
struct usb_interface *intf;
+ bool handled;
+ struct usb_device_vendor_ops *ops = usb_vendor_get_ops();

if (udev->state == USB_STATE_NOTATTACHED) {
status = -ENODEV;
goto done;
}
+
+ if (ops && ops->usb_dev_resume) {
+ handled = ops->usb_dev_resume(udev, msg);
+ if (handled)
+ goto done;
+ }
+
udev->can_submit = 1;

/* Resume the device */
diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h
index 82538daac8b8..9ccb8683071d 100644
--- a/drivers/usb/core/usb.h
+++ b/drivers/usb/core/usb.h
@@ -220,3 +220,8 @@ extern acpi_handle usb_get_hub_port_acpi_handle(struct usb_device *hdev,
static inline int usb_acpi_register(void) { return 0; };
static inline void usb_acpi_unregister(void) { };
#endif
+
+struct usb_device_vendor_ops {
+ bool (*usb_dev_suspend)(struct usb_device *udev, pm_message_t msg);
+ bool (*usb_dev_resume)(struct usb_device *udev, pm_message_t msg);
+};
--
2.39.0.rc1.256.g54fd8350bd-goog