Hi guys,
We've encountered an issue whit the Keystone 2 target regarding the
real-time / hardware clock.
The problem first appears during the boot process, as shown below in
the log. Seems that the rtc device (eg. rtc0) is not present.
...
[ 0.592146] 8021q: 802.1Q VLAN Support v1.8
[ 0.592817] sctp: Hash tables configured (established 16384 bind 16384)
[ 0.593721] NET: Registered protocol family 40
[ 0.594339] VFP support v0.3: implementor 41 architecture 4 part 30 variant f rev 0
[ 0.595360] Registering SWP/SWPB emulation handler
[ 0.596230] drivers/rtc/hctosys.c: unable to open rtc device (rtc0)
[ 0.597856] keystone-netcp 2090000.netcp: initializing cpsw version 1.3 (1) SGMII identification value 0x4ed1
[ 0.599351] keystone-netcp 2090000.netcp: Created a cpsw ale engine
[ 0.600184] keystone-netcp 2090000.netcp: initialized cpsw ale revision 1.3
[ 0.610193] keystone-netcp 2090000.netcp: Using Packet Accelerator Firmware version 0x01030008
[ 0.611338] keystone-netcp 2090000.netcp: pa_clk_rate(204800000 HZ),mult(20000),shift(12)
...
root@keystone-evm:~# ls -al /dev/misc/rtc
ls: /dev/misc/rtc: No such file or directory
root@keystone-evm:~# ls -al /dev/rtc0
ls: /dev/rtc0: No such file or directory
Another issue, linked to the rt/hw clock and maybe to the above
problem, can be seen while running the 'date' command, in the sense
that if you run the command several times for *at least* 4-5
seconds, the command will output *only* a time change (the seconds
will increment only once during the 4-5 seconds of 'date' command
run one after another).
Was this problem reproduced by anyone else ?
Could this be
#1. a kernel missing configuration (the following are missing from
the .config, adding them and rebuilding the kernel did not solved
any of the issues):
CONFIG_RTC_CLASS=y
CONFIG_RTC_HCTOSYS=y
CONFIG_RTC_HCTOSYS_DEVICE="rtc0"
CONFIG_RTC_INTF_SYSFS=y
CONFIG_RTC_INTF_PROC=y
CONFIG_RTC_INTF_DEV=y
#2. or a clock frequency:
in arch/arm/boot/dts/k2hk-evm.dts we should then add the
'clock-frequency' to a proper value:
timer {
compatible = "arm,armv7-timer";
interrupts = <1 13 0xf08 1 14 0xf08>;
+ clock-frequency = <134221720>;
};
#3. or a hardware problem ?
We are not sure on the cause of this rt/hw clock issue yet; any
advice/input would help us a lot.
Thank you,
Valentin