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net: ethernet: ti: cpts: switch to use new .gettimex64() interface 

The CPTS HW latches and saves CPTS counter value in CPTS fifo immediately
after writing to CPSW_CPTS_PUSH.TS_PUSH (bit 0), so the total time that the
driver needs to read the CPTS timestamp is the time required CPSW_CPTS_PUSH
write to actually reach HW.

Hence switch CPTS driver to implement new .gettimex64() callback for more
precise measurement of the offset between a PHC and the system clock which
is measured as time between
  write(CPSW_CPTS_PUSH)
  read(CPSW_CPTS_PUSH)

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Grygorii Strashko 2020-04-23 17:20:16 +03:00 committed by David S. Miller
parent 0d6df3e613
commit 856e59ab7e
1 changed files with 14 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
drivers/net/ethernet/ti/cpts.c
View File

@ -203,9 +203,13 @@ static u64 cpts_systim_read(const struct cyclecounter *cc)
return READ_ONCE(cpts->cur_timestamp);
}
static void cpts_update_cur_time(struct cpts *cpts, int match)
static void cpts_update_cur_time(struct cpts *cpts, int match,
struct ptp_system_timestamp *sts)
{
ptp_read_system_prets(sts);
cpts_write32(cpts, TS_PUSH, ts_push);
cpts_read32(cpts, ts_push);
ptp_read_system_postts(sts);
if (cpts_fifo_read(cpts, match) && match != -1)
dev_err(cpts->dev, "cpts: unable to obtain a time stamp\n");
@ -234,7 +238,7 @@ static int cpts_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
cpts->mult_new = neg_adj ? mult - diff : mult + diff;
cpts_update_cur_time(cpts, CPTS_EV_PUSH);
cpts_update_cur_time(cpts, CPTS_EV_PUSH, NULL);
spin_unlock_irqrestore(&cpts->lock, flags);
@ -253,15 +257,17 @@ static int cpts_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
return 0;
}
static int cpts_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
static int cpts_ptp_gettimeex(struct ptp_clock_info *ptp,
struct timespec64 *ts,
struct ptp_system_timestamp *sts)
{
u64 ns;
unsigned long flags;
struct cpts *cpts = container_of(ptp, struct cpts, info);
unsigned long flags;
u64 ns;
spin_lock_irqsave(&cpts->lock, flags);
cpts_update_cur_time(cpts, CPTS_EV_PUSH);
cpts_update_cur_time(cpts, CPTS_EV_PUSH, sts);
ns = timecounter_read(&cpts->tc);
spin_unlock_irqrestore(&cpts->lock, flags);
@ -302,7 +308,7 @@ static long cpts_overflow_check(struct ptp_clock_info *ptp)
spin_lock_irqsave(&cpts->lock, flags);
cpts_update_cur_time(cpts, -1);
cpts_update_cur_time(cpts, -1, NULL);
ns = timecounter_read(&cpts->tc);
@ -326,7 +332,7 @@ static const struct ptp_clock_info cpts_info = {
.pps = 0,
.adjfreq = cpts_ptp_adjfreq,
.adjtime = cpts_ptp_adjtime,
.gettime64 = cpts_ptp_gettime,
.gettimex64 = cpts_ptp_gettimeex,
.settime64 = cpts_ptp_settime,
.enable = cpts_ptp_enable,
.do_aux_work = cpts_overflow_check,