Hi Jacob,
I tried to test the driver with testptp and it seems to be working as
expected.
I was able to settime, gettime, adjtime, adjfreq got the expected values.
The setup I am using is explained below.
MASTER [Linux Ubuntu System with Oregano NIC card for Hardware Time
Stamping] < --> SLAVE [Xilinx FPGA Device which supports the HW time
stamping ]
Slave is getting its clock from an external clock source which is running
at 200MHz Frequency.
Xilinx Ethernet Driver which is used for HW timestamping, it is available
on github @
https://github.com/Xilinx/linux-xlnx/blob/master/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
settime, gettime, adjtime, adjfreq functionality is developed in a separate
timer driver which is not available on the github but this driver is pretty
straight forward.
When debugging with PTP4l application, In the normal scenario if
step_threshold is set to 0.0, I have observed that
- during s1 state *adjtime *gets called with ADJ_SETOFFSET | ADJ_NANO modes
to adjust the clock.
- when slave moves to s2 state, upon receiving the sync and followup
packets, *adjfreq *is called for every 1 second to adjust the frequency of
the clock
adjtime and adjfreq are implemented in timer driver as below.
static int xlnx_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
{
struct xlnx_ptp_timer *timer = container_of(ptp, struct
xlnx_ptp_timer,
ptp_clock_info);
int neg_adj = 0;
u64 freq = 0;
u32 diff = 0;
u32 incval = 0;
/* External clock source Frequency is 200MHz which is driving
the timer */
/* adjust the RTC Increment Control register by (1/200MHZ = 5ns) */
/* resolution of the increment register is 1/1048576 */
/* hence 5 * 1048576 = 0x500000 - value to be written to the
register */
incval = 0x500000;
if (ppb < 0) {
neg_adj = 1;
ppb = -ppb;
}
freq = incval;
freq *= ppb;
diff = div_u64(freq, 1000000000ULL);
incval = neg_adj ? (incval - diff) : (incval + diff);
/* Write the adjusted value to the *RTC Increment Value Control
Register* */
/* Writing the adjustment value to this register intern adjusts the
nanoseconds register value by the hw */
return 0;
}
static int xlnx_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
{
unsigned long flags = 0;
struct xlnx_ptp_timer *timer = container_of(ptp, struct
xlnx_ptp_timer,
ptp_clock_info);
struct timespec offset, then = ns_to_timespec(delta);
spin_lock_irqsave(&timer->reg_lock, flags);
/* Read the seconds and nano seconds from the RTC Seconds and RTC
Nano Seconds Registers */
xlnx_rtc_offset_read(timer, &offset);
/* set the current offset values */
offset = then;
/* Write the seconds and nano seconds to the *RTC Seconds* and *RTC
Nano Seconds* Registers */
xlnx_rtc_offset_write(timer, (const struct timespec *)&offset);
spin_unlock_irqrestore(&timer->reg_lock, flags);
return 0;
}
could you please review these functions and let us know if there are any
issues.
Thank you.
Best Regards,
Sujatha
On Wed, Feb 17, 2016 at 9:37 AM, Sujatha Guguloth <sujatha.gul...@gmail.com>
wrote:
> Thank you Jocob and Lichavar for your quick replies.
>
> I will try with testptp.
>
> Best Regards,
> Sujatha
>
> On Wed, Feb 17, 2016 at 1:26 AM, Keller, Jacob E <jacob.e.kel...@intel.com
> > wrote:
>
>> Hi,
>>
>> On Tue, 2016-02-16 at 16:20 +0530, Sujatha Guguloth wrote:
>> > Hi Miroslav Lichvar,
>> >
>> > What aspects of driver/HW needs to be fixed. could you please
>> > elaborate more on this.
>> >
>> >
>> > Best Regards,
>> > Sujatha
>>
>> At this point, we really can't offer more advice unless the source is
>> available. The driver is definitely doing something funky as evidenced
>> above, and unless the driver is available we can't really comment.
>>
>> I suggest using the provided testptp tool provided in the Linux Kernel
>> documentation to do some sanity checks on all your ptp code paths for
>> adjtime, settime, gettime, adjfreq, etc. Verify these are doing what
>> you expect before you continue your debugging with ptp4l.
>>
>> Regards,
>> Jake
>
>
>
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