| /* Copyright 2019 The ChromiumOS Authors |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef __CROS_EC_FPC_TIMEBASE_H |
| #define __CROS_EC_FPC_TIMEBASE_H |
| |
| /** |
| * @file fpc_timebase.h |
| * @brief Timebase based on a system tick. |
| * |
| * Supplies tick counter and wait operation(s). |
| */ |
| |
| #include "common.h" |
| |
| #include <stdint.h> |
| |
| /** |
| * @brief Reads the system tick counter. |
| * |
| * @details To handle tick counter wrap around when checking for timeout, make |
| * sure to do the calculation in the following manner: |
| * "if ((current_tick - old_tick) > timeout) {" |
| * Example: current time (uint32_t) = 10 ticks |
| * old time (uint32_t) = 30 ticks before overflow of uint32_t |
| * current_time - old_time = 10 - (2**32 - 30) -> wraps around to 40 |
| * |
| * @return Tick count since system startup. [ms] |
| */ |
| __staticlib_hook uint32_t fpc_timebase_get_tick(void); |
| |
| /** |
| * @brief Busy wait. |
| * |
| * @param[in] ms Time to wait [ms]. |
| * 0 => return immediately |
| * 1 => wait at least 1ms etc. |
| */ |
| __staticlib_hook void fpc_timebase_busy_wait(uint32_t ms); |
| |
| #endif /* __CROS_EC_FPC_TIMEBASE_H */ |
