ticks.hpp

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/**
 * @file ticks.hpp
 * @brief Tick counter interface for profiling
 *
 * Includes the platform-specific timing backend (generated by sloth from
 * the MCU manifest's timing capability) and provides the TickScope RAII
 * helper. The generated backend supplies:
 *   - sbl::hw::timing::init()  — call once at startup
 *   - sbl::hw::timing::read()  — free-running counter (wraps at 2^32)
 *   - sbl::hw::timing::rate()  — ticks per second
 *
 * Platform implementations (selected by MCU manifest):
 *   - dwt:             ARM DWT CYCCNT (hardware cycles)
 *   - posix_monotonic:  clock_gettime CLOCK_MONOTONIC (nanoseconds)
 *   - sdk_timer:        Pico SDK hardware timer (microseconds)
 */
#ifndef SBL_COMMON_DIAGNOSTICS_TICKS_HPP_
#define SBL_COMMON_DIAGNOSTICS_TICKS_HPP_
 
#include <cstdint>
#include <sbl/hw/config/timing.hpp>
 
namespace sbl::diagnostics {
 
/// Initialize the platform timing backend. Call once at startup.
inline void ticks_init() { sbl::hw::timing::init(); }
 
/// Read current tick count (free-running, wraps at 2^32).
inline uint32_t ticks() { return sbl::hw::timing::read(); }
 
/// Tick rate in Hz (ticks per second).
inline constexpr uint32_t tick_rate() { return sbl::hw::timing::rate(); }
 
/// RAII scope for measuring a block of code.
/// Usage: volatile uint32_t elapsed; { TickScope s(elapsed); /* code */ }
struct TickScope {
    uint32_t start_;
    volatile uint32_t& result_;
 
    explicit TickScope(volatile uint32_t& out)
        : start_(ticks()), result_(out) {}
    ~TickScope() { result_ = ticks() - start_; }
};
 
} // namespace sbl::diagnostics
 
#endif // SBL_COMMON_DIAGNOSTICS_TICKS_HPP_