29 lines
1.1 KiB
ReStructuredText
29 lines
1.1 KiB
ReStructuredText
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.. _usb_device_stack_api:
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USB device stack API
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####################
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API reference
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*************
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There are two ways to transmit data, using the 'low' level read/write API or
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the 'high' level transfer API.
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Low level API
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To transmit data to the host, the class driver should call usb_write().
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Upon completion the registered endpoint callback will be called. Before
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sending another packet the class driver should wait for the completion of
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the previous write. When data is received, the registered endpoint callback
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is called. usb_read() should be used for retrieving the received data.
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For CDC ACM sample driver this happens via the OUT bulk endpoint handler
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(cdc_acm_bulk_out) mentioned in the endpoint array (cdc_acm_ep_data).
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High level API
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The usb_transfer method can be used to transfer data to/from the host. The
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transfer API will automatically split the data transmission into one or more
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USB transaction(s), depending endpoint max packet size. The class driver does
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not have to implement endpoint callback and should set this callback to the
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generic usb_transfer_ep_callback.
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.. doxygengroup:: _usb_device_core_api
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