Introduction

HW/IP FEATURES:

• Maintains the real time, even when the device is off (powered-off).
• Has the capability to generate an alarm at a specific time and date.
• Includes the means for periodic software calibration of the RTC.
• Includes logic to correct the static fractional inaccuracy of the oscillator.
• Keeps track of time within a window of more than 136 years (232 seconds) from a reference point.
• Implemented as three counters.
• 16-bit tick counter creates one second based on the crystal clock.
• 4-bit fraction counter keeps track of the static crystal errors in one second that is less than one oscillator tick.
• 32-bit seconds counter holds the real time and allows on-demand reload whenever current time of the RTC is set.
• Allows wake-up at a specific second within the 136 years (32-bit alarm)

Missing features, Known Issues, limitations

• None

Overview of Linux RTC Framework

Kernel Configuration:

config RTC_DRV_ZYNQMP
        tristate "Xilinx Zynq Ultrascale+ MPSoC RTC"
        depends on OF
        help
          If you say yes here you get support for the RTC controller found on
          Xilinx Zynq Ultrascale+ MPSoC.
 
 

[*] EDAC (Error Detection And Correction) reporting  --->
[*] Real Time Clock  --->
[*] DMA Engine support  --->
[*] Auxiliary Display support  --->

--- Real Time Clock
[*]   Set system time from RTC on startup and resume
[*]   Set the RTC time based on NTP synchronization (NEW)
(rtc0)  RTC used to set the system time
[ ]   RTC debug support
    *** RTC interfaces ***
[*]   /sys/class/rtc/rtcN (sysfs)
[*]   /proc/driver/rtc (procfs for rtcN)
[*]   /dev/rtcN (character devices)
[ ]     RTC UIE emulation on dev interface
< >   Test driver/device
........
       *** Platform RTC drivers ***
........
        < >   ST M48T86/Dallas DS12887
        < >   ST M48T35
        < >   ST M48T59/M48T08/M48T02
        < >   Oki MSM6242 (NEW)
        < >   TI BQ4802
        < >   Ricoh RP5C01 (NEW)
        < >   EM Microelectronic V3020
        <*>   Xilinx Zynq Ultrascale+ MPSoC RTC (NEW)
       *** on-CPU RTC drivers ***

Testing Procedure

1.Get current date and time using "date" command
2.Set date and time using following commanddate -s "2015-09-08 13:36:00"
3. Verify the same using date command again.
 

Mainline status

This driver is currently in sync with the mainline kernel except for the following:

   rtc: zynqmp: Add calibration set and get support 

ChangeLog

• 2020.1

  • None

• 2020.2

  • summary:
    • rtc: zynqmp: Clear alarm interrupt status before interrupt enable
  • Commits
    • 2694c8

• 2020.1

  • summary:
    • rtc: rtc-zynqmp: Add calibration set and get support
  • Commits
    • a4704c54 :Add calibration set and get support

• 2019.2

  • Summary
    • rtc: rtc-zynqmp: Clear alarm interrupt status before intr enable
  • Commits
    • 771fb636 rtc: rtc-zynqmp: Clear alarm interrupt status before intr enable

• 2019.1

  • None

• 2018.3

  • None

• 2018.2

  • None

• 2018.1

  • None

• 2017.4

  • None

• 2017.3

  • None

• 2017.2

  • None

• 2017.1

  • None

• 2016.3

  • None

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