| 1 | /* |
| 2 | * RTC configuration and clock read |
| 3 | * |
| 4 | * Copyright (c) 2003-2021 QEMU contributors |
| 5 | * |
| 6 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 7 | * of this software and associated documentation files (the "Software"), to deal |
| 8 | * in the Software without restriction, including without limitation the rights |
| 9 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 10 | * copies of the Software, and to permit persons to whom the Software is |
| 11 | * furnished to do so, subject to the following conditions: |
| 12 | * |
| 13 | * The above copyright notice and this permission notice shall be included in |
| 14 | * all copies or substantial portions of the Software. |
| 15 | * |
| 16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 17 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| 19 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 20 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 21 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| 22 | * THE SOFTWARE. |
| 23 | */ |
| 24 | |
| 25 | #ifndef SYSTEM_RTC_H |
| 26 | #define SYSTEM_RTC_H |
| 27 | |
| 28 | /** |
| 29 | * qemu_get_timedate: Get the current RTC time |
| 30 | * @tm: struct tm to fill in with RTC time |
| 31 | * @offset: offset in seconds to adjust the RTC time by before |
| 32 | * converting to struct tm format. |
| 33 | * |
| 34 | * This function fills in @tm with the current RTC time, as adjusted |
| 35 | * by @offset (for example, if @offset is 3600 then the returned time/date |
| 36 | * will be one hour further ahead than the current RTC time). |
| 37 | * |
| 38 | * The usual use is by RTC device models, which should call this function |
| 39 | * to find the time/date value that they should return to the guest |
| 40 | * when it reads the RTC registers. |
| 41 | * |
| 42 | * The behaviour of the clock whose value this function returns will |
| 43 | * depend on the -rtc command line option passed by the user. |
| 44 | */ |
| 45 | void qemu_get_timedate(struct tm *tm, time_t offset); |
| 46 | |
| 47 | /** |
| 48 | * qemu_timedate_diff: Return difference between a struct tm and the RTC |
| 49 | * @tm: struct tm containing the date/time to compare against |
| 50 | * |
| 51 | * Returns the difference in seconds between the RTC clock time |
| 52 | * and the date/time specified in @tm. For example, if @tm specifies |
| 53 | * a timestamp one hour further ahead than the current RTC time |
| 54 | * then this function will return 3600. |
| 55 | */ |
| 56 | time_t qemu_timedate_diff(struct tm *tm); |
| 57 | |
| 58 | #endif |