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gex-core/units/1wire/_ow_search.h

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//
// Created by MightyPork on 2018/02/01.
//
#ifndef GEX_F072_OW_SEARCH_H
#define GEX_F072_OW_SEARCH_H
#ifndef OW_INTERNAL
#error bad include!
#endif
#include <stdint.h>
#include <stdbool.h>
#include "unit_base.h"
// --------------------------------------------------------------------------------------
/**
* Data type holding a romcode
*/
typedef uint8_t ow_romcode_t[8];
/**
* Get a single bit from a romcode
*/
#define ow_code_getbit(code, index) (bool)((code)[(index) >> 3] & (1 << ((index) & 7)))
/**
* Convert to unsigned 64-bit integer
* (works only on little-endian systems - eg. OK on x86/x86_64, not on PowerPC)
*/
#define ow_romcode_to_u64(code) (*((uint64_t *) (void *)(code)))
/**
* States of the search algorithm
*/
enum ow_search_result {
OW_SEARCH_DONE = 0,
OW_SEARCH_MORE = 1,
OW_SEARCH_FAILED = 2,
};
/**
* Internal state of the search algorithm.
* Check status to see if more remain to be read or an error occurred.
*/
struct ow_search_state {
int8_t prev_last_fork;
ow_romcode_t prev_code;
uint8_t command;
enum ow_search_result status;
bool first;
bool test_checksums;
error_t error;
};
/**
* Init the search algorithm state structure
*
* @param[out] state - inited struct
* @param[in] command - command to send for requesting the search (e.g. SEARCH_ROM)
* @param[in] test_checksums - verify checksums of all read romcodes
*/
void ow_search_init(Unit *unit, uint8_t command, bool test_checksums);
/**
* Perform a search of the 1-wire bus, with a state struct pre-inited
* using ow_search_init().
*
* Romcodes are stored in the provided array in a numerically ascending order.
*
* This function may be called repeatedly to retrieve more addresses than could fit
* in the address buffer.
*
* @param[in,out] state - search state, used for multiple calls with limited buffer size
* @param[out] codes - buffer for found romcodes
* @param[in] capacity - buffer capacity
* @return number of romcodes found. Search status is stored in `state->status`,
* possible error code in `status->error`
*/
uint32_t ow_search_run(Unit *unit, ow_romcode_t *codes, uint32_t capacity);
#endif //GEX_F072_OW_SEARCH_H