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#ifndef ISO14443_LAYER2A_H_
#define ISO14443_LAYER2A_H_
#include "ssc_buffer.h"
/* Callback type for iso14443_receive().
* Parameter buffer is being passed a pointer to an SSC Rx buffer structure that this receive happened
* on. You might want to pass this into iso14443a_decode_miller().
* Parameter in_irq is true if the callback has been called while still in IRQ mode. It must then *NOT*
* perform any calls that might upset the IRQ processing. Especially it may not call into FreeRTOS or
* any parts of the applications that do.
*/
typedef void (*iso14443_receive_callback_t)(ssc_dma_rx_buffer_t *buffer, u_int8_t in_irq);
/* Wait for and receive a frame. Parameters callback and buffer are optional. If you omit them you'll lose
* the received frame, obviously.
* Parameter callback is a callback function that will be called for each received frame and might
* then trigger a response.
* Parameter buffer is an output pointer to a pointer to an SSC Rx buffer structure containing the
* received frame.
* Parameter timeout gives an optional timeout for the receive operation after which the receive will
* be aborted. When timeout is 0 the receive will not time out.
* This call will block until a frame is received or an exception happens. Obviously it must not be run
* from IRQ context.
*
* Warning: When you get a buffer from the function then it's state is set to PROCESSING and you must
* FREE it yourself.
*
* Return values:
* >= 0 Frame received, return value is buffer length (yes, 0 is a valid buffer length)
* -ENETDOWN PLL is not locked or PLL lock lost
* -ETIMEDOUT Receive timed out without receiving anything (usually not regarded an error condition)
* -EBUSY A Tx is currently running or pending; can't receive
* -EALREADY There's already an iso14443_receive() invocation running
*/
extern int iso14443_receive(iso14443_receive_callback_t callback, ssc_dma_rx_buffer_t **buffer, unsigned int timeout);
/*
* Transmit a frame. Starts transmitting fdt carrier cycles after the end of the received frame.
* Parameters buffer and fdt specify the SSC Tx buffer to be sent and the frame delay time in carrier cycles.
* When parameter async is set then this call will only schedule the buffer for sending and return immediately,
* otherwise the call will block until the buffer has been sent completely, until the specified timeout is reached
* or an error occurs.
* This function may be run from IRQ context, especially from within the iso14443_receive callback, with the async
* parameter set.
*
* Note: When your callback calls iso14443_transmit() from IRQ context it must set the async parameter to have transmit
* return immediately and then not block within the callback. When the scheduled transmission has not happened by the next
* time you call iso14443_receive() it will abort with -EBUSY and you can then either decide to wait for the transmission
* to go through, or abort the scheduled transmission with iso14443_tx_abort(). You can check for whether a Tx is currently
* pending or running with iso14443_tx_busy().
*/
extern int iso14443_transmit(ssc_dma_tx_buffer_t *buffer, unsigned int fdt, u_int8_t async, unsigned int timeout);
extern int iso14443_tx_abort(void);
extern int iso14443_tx_busy(void);
/*
* Wait for the presence of a reader to be detected.
* Returns 0 when the PLL is locked.
*/
extern int iso14443_wait_for_carrier(unsigned int timeout);
/* Initialize the layer 2 transceiver code.
* Parameter enable_fast_receive, when set, will enable special code to guarantee fast response times
* for frames shorter than or equal to 56 data bits (bit oriented anticollision frame length). This
* generally involves running the callback from an IRQ handler.
*/
extern int iso14443_layer2a_init(u_int8_t enable_fast_receive);
extern u_int8_t iso14443_set_fast_receive(u_int8_t enable_fast_receive);
extern u_int8_t iso14443_get_fast_receive(void);
#endif /*ISO14443_LAYER2A_H_*/
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