LPC Microcontrollers中的主题 Re: USB re-enumeration

USB re-enumeration

emblink182 — Thu, 20 Aug 2020 15:42:17 GMT

Hi, I have a question about USB HS enumeration on LPC54605J512 MCU.

I need to change the polling rate of the USB device in runtime. In order to do that I need to force the host to re-enumerate the device. I have tried to call USB_DeviceStop() and USB_DeviceRun() right after, but most of the time device fails to enumerate. Reboot MCU and start with a new configuration is not an option for my particular case.

Is there any way to do that with USB stack functions or maybe manual registers settings?

Re: USB re-enumeration

belmontbob59 — Thu, 20 Aug 2020 21:03:56 GMT

What I do to re-enumerate w/o MCU reset (USB0 or USB1):

To bring the stack up:

a)call USB_DeviceInit()

b)enable USB's IRQ

c)call USB_DeviceRun()

to bring the stack down:

a)call USB_DeviceStop()

b)disable USB's IRQ

c)call USB_DeviceDeinit()

Re: USB re-enumeration

emblink182 — Wed, 02 Sep 2020 12:56:31 GMT

Hi, thanks for your suggestion and sorry for the late response.

I figured out that this method is working well on non-RTOS examples. But unfortunately, it doesn't with the FreeRTOS example. If I call usbReEnumerate() from other contexts, such as the timer task, the USB fails to enumerate. And I'm struggling to answer why that happening. I used lpcxpresso54628_dev_hid_mouse_freertos project with minor modifications as an experimental ground.

#define USB_DEVICE_CONFIG_LPCIP3511HS (1U)

#define USB_DEVICE_CONFIG_USE_TASK (1U)

#define USB_DEVICE_CONFIG_COMPLIANCE_TEST (1U)

#define USB_DEVICE_CONFIG_DETACH_ENABLE (1U)

In mouse.c I have added // TEST_CODE comment in places where example was modified. Basically I created a one shot 1 sec software timer, starting it after usb got configured and call usbReEnumerate() in timer callback. Modified files are in attachment.

static void usbReEnumerate(TimerHandle_t xTimer) // TEST_CODE
{
(void) xTimer;
usb_status_t res = kStatus_USB_Success;
// usb_echo("usbReEnumerate\r\n");

if (g_UsbDeviceHidMouse.attach) {
USB_DeviceStop(g_UsbDeviceHidMouse.deviceHandle); // always returns kStatus_USB_Error
g_UsbDeviceHidMouse.attach = 0; // allows ignoring suspend event after re-enable.
NVIC_DisableIRQ(USB1_IRQn);
usb_status_t res = USB_DeviceClassDeinit(CONTROLLER_ID);
// usb_status_t res = USB_DeviceDeinit(g_UsbDeviceHidMouse.deviceHandle);

// res |= USB_DeviceInit(CONTROLLER_ID, USB_DeviceCallback, &g_UsbDeviceHidMouse.deviceHandle);
res |= USB_DeviceClassInit(CONTROLLER_ID, &g_UsbDeviceHidConfigList, &g_UsbDeviceHidMouse.deviceHandle);
NVIC_ClearPendingIRQ(USB1_IRQn);
NVIC_EnableIRQ(USB1_IRQn);
USB_DeviceRun(g_UsbDeviceHidMouse.deviceHandle); // always returns kStatus_USB_Error
}
assert(kStatus_USB_Success == res);
}

I also tried to use directly USB_DeviceInit() and USB_DeviceDeinit() but that didn't work also. USB_DeviceClassInit and USB_DeviceClassDeinit eventually call those functions so I think it's not a big deal here. Strange thing happens if uncomment // usb_echo("usbReEnumerate\r\n"); After that usb re-enumerates succesfully. And that's confusing.

Re: USB re-enumeration

belmontbob59 — Thu, 03 Sep 2020 15:57:27 GMT

The call to NVIC_ClearPendingIRQ(USB1_IRQn); is invalid after the call to USB_DeviceClassInit() because you are messing up with lpcip3511.c workflow at that point.

Re: USB re-enumeration

emblink182 — Thu, 03 Sep 2020 16:25:59 GMT

I ran this code on a non-RTOS example and it works fine. I also tried not to call NVIC_ClearPendingIRQ(USB1_IRQn); in the RTOS example but the behavior didn't change.

Re: USB re-enumeration

emblink182 — Thu, 03 Sep 2020 16:42:59 GMT

And what's really strange that usb_echo("usbReEnumerate\r\n"); line fixes this issue. I can't explain this phenomenon.

Re: USB re-enumeration

emblink182 — Tue, 20 Oct 2020 12:51:48 GMT

Solved this problem by adding a custom notification and device event.

Add a case kUSB_DeviceNotifyRestart in USB_DeviceNotification and call

USB_DeviceRestartNotification from there.

Eventually, USB_DeviceCallback gets called with event param kUSB_DeviceEventRestart from USB task context.

sendUsbRestartCommand called manually from other task context and pushes re-enumeration notification to the internal queue.

This code is not breaking the internal queue of the driver.

Re enumeration worked fine after that.