| 1 | What: /sys/class/rtc/ |
| 2 | Date: March 2006 |
| 3 | KernelVersion: 2.6.17 |
| 4 | Contact: [email protected] |
| 5 | Description: |
| 6 | The rtc/ class subdirectory belongs to the RTC subsystem. |
| 7 | |
| 8 | What: /sys/class/rtc/rtcX/ |
| 9 | Date: March 2006 |
| 10 | KernelVersion: 2.6.17 |
| 11 | Contact: [email protected] |
| 12 | Description: |
| 13 | The /sys/class/rtc/rtc{0,1,2,3,...} directories correspond |
| 14 | to each RTC device. |
| 15 | |
| 16 | What: /sys/class/rtc/rtcX/date |
| 17 | Date: March 2006 |
| 18 | KernelVersion: 2.6.17 |
| 19 | Contact: [email protected] |
| 20 | Description: |
| 21 | (RO) RTC-provided date in YYYY-MM-DD format |
| 22 | |
| 23 | What: /sys/class/rtc/rtcX/hctosys |
| 24 | Date: September 2009 |
| 25 | KernelVersion: 2.6.32 |
| 26 | Contact: [email protected] |
| 27 | Description: |
| 28 | (RO) 1 if the RTC provided the system time at boot via the |
| 29 | CONFIG_RTC_HCTOSYS kernel option, 0 otherwise |
| 30 | |
| 31 | What: /sys/class/rtc/rtcX/max_user_freq |
| 32 | Date: October 2007 |
| 33 | KernelVersion: 2.6.24 |
| 34 | Contact: [email protected] |
| 35 | Description: |
| 36 | (RW) The maximum interrupt rate an unprivileged user may request |
| 37 | from this RTC. |
| 38 | |
| 39 | What: /sys/class/rtc/rtcX/name |
| 40 | Date: March 2006 |
| 41 | KernelVersion: 2.6.17 |
| 42 | Contact: [email protected] |
| 43 | Description: |
| 44 | (RO) The name of the RTC corresponding to this sysfs directory |
| 45 | |
| 46 | What: /sys/class/rtc/rtcX/range |
| 47 | Date: January 2018 |
| 48 | KernelVersion: 4.16 |
| 49 | Contact: [email protected] |
| 50 | Description: |
| 51 | Valid time range for the RTC, as seconds from epoch, formatted |
| 52 | as [min, max] |
| 53 | |
| 54 | What: /sys/class/rtc/rtcX/since_epoch |
| 55 | Date: March 2006 |
| 56 | KernelVersion: 2.6.17 |
| 57 | Contact: [email protected] |
| 58 | Description: |
| 59 | (RO) RTC-provided time as the number of seconds since the epoch |
| 60 | |
| 61 | What: /sys/class/rtc/rtcX/time |
| 62 | Date: March 2006 |
| 63 | KernelVersion: 2.6.17 |
| 64 | Contact: [email protected] |
| 65 | Description: |
| 66 | (RO) RTC-provided time in 24-hour notation (hh:mm:ss) |
| 67 | |
| 68 | What: /sys/class/rtc/rtcX/offset |
| 69 | Date: February 2016 |
| 70 | KernelVersion: 4.6 |
| 71 | Contact: [email protected] |
| 72 | Description: |
| 73 | (RW) The amount which the rtc clock has been adjusted in |
| 74 | firmware. Visible only if the driver supports clock offset |
| 75 | adjustment. The unit is parts per billion, i.e. The number of |
| 76 | clock ticks which are added to or removed from the rtc's base |
| 77 | clock per billion ticks. A positive value makes a day pass more |
| 78 | slowly, longer, and a negative value makes a day pass more |
| 79 | quickly. |
| 80 | |
| 81 | What: /sys/class/rtc/rtcX/wakealarm |
| 82 | Date: February 2007 |
| 83 | KernelVersion: 2.6.20 |
| 84 | Contact: [email protected] |
| 85 | Description: |
| 86 | (RW) The time at which the clock will generate a system wakeup |
| 87 | event. This is a one shot wakeup event, so must be reset after |
| 88 | wake if a daily wakeup is required. Format is seconds since the |
| 89 | epoch by default, or if there's a leading +, seconds in the |
| 90 | future, or if there is a leading +=, seconds ahead of the |
| 91 | current alarm. |