Seeking Assistance: Implementing USB Device Suspend/Resume in User Space Driver

[Muni Sekhar]

Dear Linux USB Subsystem Community,

I hope this email finds you well. We are currently working on a USB
device driver in the Linux kernel space, which supports the
suspend/resume functionality for a USB device using the struct
usb_driver's .suspend and .resume callbacks.


In our driver code, we perform a check to determine if the device has
remote wakeup capability. If the device supports remote wakeup, we
enable the device's autosuspend mode by setting the struct
usb_device->dev.power.autosuspend_delay parameter and then calling
usb_enable_autosuspend().


Similarly, to resume the suspended device, we expose an API to user
space via IOCTL. In this process, we set struct
usb_device->dev.power.autosuspend_delay to -1 and then call
usb_disable_autosuspend().


While we have successfully converted most of the USB device driver
functionality from kernel space to user space using libusb, we are now
seeking guidance on how to implement USB device suspend/resume in user
space. Specifically, we would like to know if libusb provides support
for achieving the suspend/resume functionality mentioned above.
Additionally, any insights or suggestions on how to accomplish this
task would be greatly appreciated.


It's worth mentioning that our USB device driver also supports
Bulk\Coontrol I/O transfers and other functionalities.


Thank you in advance for any assistance you can provide. I look
forward to your valuable inputs and recommendations.


-- 
Thanks,
Sekhar