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#ifndef _SSC_H
#define _SSC_H
#include "queue.h"
#include "iso14443_layer3a.h"
extern void ssc_rx_start(void);
extern void ssc_rx_stop(void);
/* Rx/Tx initialization separate, since Tx disables PWM output ! */
extern void ssc_tx_init(void);
extern void ssc_rx_init(void);
extern void ssc_fini(void);
extern void ssc_rx_stop(void);
extern void ssc_rx_unthrottle(void);
extern void __ramfunc ssc_rx_stop_frame_ended(void);
enum ssc_mode {
SSC_MODE_NONE,
SSC_MODE_14443A_SHORT,
SSC_MODE_14443A_STANDARD,
SSC_MODE_14443A,
SSC_MODE_14443B,
SSC_MODE_EDGE_ONE_SHOT,
SSC_MODE_CONTINUOUS,
};
extern void ssc_rx_mode_set(enum ssc_mode ssc_mode);
typedef void (*ssc_irq_ext_t)(u_int32_t ssc_sr, enum ssc_mode ssc_mode, u_int8_t* samples);
/* A fast method to extend the IRQ handler from the higher level code, e.g. to prepare
* an ATQA answer to REQA or WUPA in iso14443_layer3a. Normally I'd use the FreeRTOS
* primitives to wake the task and then do everything in task context, but the delay
* from SSC IRQ to the task returning from xQueueReceive is around 165us. Additionally to the
* delay from end of communication to SSC IRQ which is around 50us. This results in way more delay
* than acceptable for the synchronous responses (around 87us).*/
extern ssc_irq_ext_t ssc_set_irq_extension(ssc_irq_ext_t ext_handler);
/* These are various SSC performance metrics that can be queried */
typedef enum {
OVERFLOWS, /* Overflows (e.g. no free buffer when reloading DMA controller) */
BUFFER_ERRORS, /* Internal buffer management errors */
FREE_BUFFERS, /* Free RX buffers */
LATE_FRAMES, /* Frames that were not ready to be sent when the FDT passed; e.g. sent too late */
SSC_ERRORS, /* General error count, e.g. OVERFLOWS + BUFFER_ERRORS */
} ssc_metric;
extern int ssc_get_metric(ssc_metric metric);
#define SSC_RX_BUFFER_SIZE 2048
#define SSC_DMA_BUFFER_COUNT 4
#if SSC_RX_BUFFER_SIZE < ISO14443A_MAX_RX_FRAME_SIZE_IN_BITS
#undef SSC_RX_BUFFER_SIZE
#define SSC_RX_BUFFER_SIZE ISO14443A_MAX_RX_FRAME_SIZE_IN_BITS
#endif
typedef enum {
FREE=0, /* Buffer is free */
PENDING, /* Buffer has been given to the DMA controller and is currently being filled */
FULL, /* DMA controller signalled that the buffer is full */
PROCESSING,/* The buffer is currently processed by the consumer (e.g. decoder) */
PREFILLED, /* The buffer has been prefilled for later usage (only used for TX) */
} ssc_dma_buffer_state_t;
typedef struct {
enum ssc_mode mode;
u_int16_t transfersize_ssc;
u_int16_t transfersize_pdc;
u_int16_t transfers;
} ssc_mode_def;
typedef struct {
volatile ssc_dma_buffer_state_t state;
u_int32_t len_transfers; /* Length of the content, in transfers */
const ssc_mode_def *reception_mode; /* Pointer to the SSC mode definition that the buffer has been loaded for (affects element size and count) */
u_int8_t data[SSC_RX_BUFFER_SIZE];
} ssc_dma_rx_buffer_t;
extern xQueueHandle ssc_rx_queue;
/* in bytes, used for the sample buffer that holds the subcarrier modulation data at fc/8 = 1695 MHz */
#define SSC_TX_BUFFER_SIZE ((MAXIMUM_FRAME_SIZE*( (8+1)*2 ) ) + 2 + 2)
typedef struct {
volatile ssc_dma_buffer_state_t state;
u_int32_t len; /* Length of the content */
void *source; /* Source pointer for a prefilled buffer; set to NULL if not used */
u_int8_t data[SSC_TX_BUFFER_SIZE];
} ssc_dma_tx_buffer_t;
/* Declare one TX buffer. This means that only one buffer can ever be pending for sending. That's because
* this buffer must be huge (one frame of 256 bytes of subcarrier modulation data at 1695 MHz sample
* rate is approx 4k bytes). */
extern ssc_dma_tx_buffer_t ssc_tx_buffer;
extern void ssc_tx_start(ssc_dma_tx_buffer_t *buf);
extern volatile u_int32_t ssc_tx_fiq_fdt_cdiv;
extern volatile u_int32_t ssc_tx_fiq_fdt_ssc;
#endif
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