diff options
| -rw-r--r-- | docs/library/machine.USBDevice.rst | 20 | ||||
| -rw-r--r-- | shared/tinyusb/mp_usbd_runtime.c | 15 |
2 files changed, 25 insertions, 10 deletions
diff --git a/docs/library/machine.USBDevice.rst b/docs/library/machine.USBDevice.rst index 82897b280..e02d3c02d 100644 --- a/docs/library/machine.USBDevice.rst +++ b/docs/library/machine.USBDevice.rst @@ -130,15 +130,25 @@ Methods Second argument is a memoryview to read the USB control request data for this stage. The memoryview is only valid until the - callback function returns. + callback function returns. Data in this memoryview will be the same + across each of the three stages of a single transfer. + + A successful transfer consists of this callback being called in sequence + for the three stages. Generally speaking, if a device wants to do + something in response to a control request then it's best to wait until + the ACK stage to confirm the host controller completed the transfer as + expected. The callback should return one of the following values: - - ``False`` to stall the endpoint and reject the transfer. + - ``False`` to stall the endpoint and reject the transfer. It won't + proceed to any remaining stages. - ``True`` to continue the transfer to the next stage. - - A buffer object to provide data for this stage of the transfer. - This should be a writable buffer for an ``OUT`` direction transfer, or a - readable buffer with data for an ``IN`` direction transfer. + - A buffer object can be returned at the SETUP stage when the transfer + will send or receive additional data. Typically this is the case when + the ``wLength`` field in the request has a non-zero value. This should + be a writable buffer for an ``OUT`` direction transfer, or a readable + buffer with data for an ``IN`` direction transfer. - ``xfer_cb`` - This callback is called whenever a non-control transfer submitted by calling :func:`USBDevice.submit_xfer` completes. diff --git a/shared/tinyusb/mp_usbd_runtime.c b/shared/tinyusb/mp_usbd_runtime.c index 0b4c79831..7ff7dd4ab 100644 --- a/shared/tinyusb/mp_usbd_runtime.c +++ b/shared/tinyusb/mp_usbd_runtime.c @@ -295,6 +295,7 @@ static bool runtime_dev_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_cont mp_obj_usb_device_t *usbd = MP_OBJ_TO_PTR(MP_STATE_VM(usbd)); tusb_dir_t dir = request->bmRequestType_bit.direction; mp_buffer_info_t buf_info; + bool result; if (!usbd) { return false; @@ -319,7 +320,7 @@ static bool runtime_dev_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_cont // Check if callback returned any data to submit if (mp_get_buffer(cb_res, &buf_info, dir == TUSB_DIR_IN ? MP_BUFFER_READ : MP_BUFFER_RW)) { - bool result = tud_control_xfer(USBD_RHPORT, + result = tud_control_xfer(USBD_RHPORT, request, buf_info.buf, buf_info.len); @@ -328,17 +329,21 @@ static bool runtime_dev_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_cont // Keep buffer object alive until the transfer completes usbd->xfer_data[0][dir] = cb_res; } - - return result; } else { // Expect True or False to stall or continue + result = mp_obj_is_true(cb_res); - if (stage == CONTROL_STAGE_ACK) { + if (stage == CONTROL_STAGE_SETUP && result) { + // If no additional data but callback says to continue transfer then + // queue a status response. + tud_control_status(rhport, request); + } else if (stage == CONTROL_STAGE_ACK) { // Allow data to be GCed once it's no longer in use usbd->xfer_data[0][dir] = mp_const_none; } - return mp_obj_is_true(cb_res); } + + return result; } static bool runtime_dev_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_t xferred_bytes) { |