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net: microchip: lan743x: add support for PTP pulse width (duty cycle)
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If the PTP_PEROUT_DUTY_CYCLE flag is set, then check if the
request_on value in ptp_perout_request matches the pre-defined
values or a toggle option.
Return a failure if the value is not supported.

Preserve the old behaviors if the PTP_PEROUT_DUTY_CYCLE flag is not
set.

Tested with an oscilloscope on EVB-LAN7430:
e.g., to output PPS 1sec period 500mS on (high) to GPIO 2.
 ./testptp -L 2,2
 ./testptp -p 1000000000 -w 500000000

Signed-off-by: Yuiko Oshino <yuiko.oshino@microchip.com>
Link: https://lore.kernel.org/r/1634046593-64312-1-git-send-email-yuiko.oshino@microchip.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Yuiko Oshino authored and Jakub Kicinski committed Oct 15, 2021
1 parent 67ca515 commit 4ece1ae
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Showing 2 changed files with 81 additions and 11 deletions.
1 change: 1 addition & 0 deletions drivers/net/ethernet/microchip/lan743x_main.h
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Original file line number Diff line number Diff line change
Expand Up @@ -279,6 +279,7 @@
#define PTP_GENERAL_CONFIG_CLOCK_EVENT_1MS_ (3)
#define PTP_GENERAL_CONFIG_CLOCK_EVENT_10MS_ (4)
#define PTP_GENERAL_CONFIG_CLOCK_EVENT_200MS_ (5)
#define PTP_GENERAL_CONFIG_CLOCK_EVENT_TOGGLE_ (6)
#define PTP_GENERAL_CONFIG_CLOCK_EVENT_X_SET_(channel, value) \
(((value) & 0x7) << (1 + ((channel) << 2)))
#define PTP_GENERAL_CONFIG_RELOAD_ADD_X_(channel) (BIT((channel) << 2))
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91 changes: 80 additions & 11 deletions drivers/net/ethernet/microchip/lan743x_ptp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -491,9 +491,10 @@ static int lan743x_ptp_perout(struct lan743x_adapter *adapter, int on,
int perout_pin = 0;
unsigned int index = perout_request->index;
struct lan743x_ptp_perout *perout = &ptp->perout[index];
int ret = 0;

/* Reject requests with unsupported flags */
if (perout_request->flags)
if (perout_request->flags & ~PTP_PEROUT_DUTY_CYCLE)
return -EOPNOTSUPP;

if (on) {
Expand All @@ -518,6 +519,7 @@ static int lan743x_ptp_perout(struct lan743x_adapter *adapter, int on,
netif_warn(adapter, drv, adapter->netdev,
"Failed to reserve event channel %d for PEROUT\n",
index);
ret = -EBUSY;
goto failed;
}

Expand All @@ -529,6 +531,7 @@ static int lan743x_ptp_perout(struct lan743x_adapter *adapter, int on,
netif_warn(adapter, drv, adapter->netdev,
"Failed to reserve gpio %d for PEROUT\n",
perout_pin);
ret = -EBUSY;
goto failed;
}

Expand All @@ -540,27 +543,93 @@ static int lan743x_ptp_perout(struct lan743x_adapter *adapter, int on,
period_sec += perout_request->period.nsec / 1000000000;
period_nsec = perout_request->period.nsec % 1000000000;

if (period_sec == 0) {
if (period_nsec >= 400000000) {
if (perout_request->flags & PTP_PEROUT_DUTY_CYCLE) {
struct timespec64 ts_on, ts_period;
s64 wf_high, period64, half;
s32 reminder;

ts_on.tv_sec = perout_request->on.sec;
ts_on.tv_nsec = perout_request->on.nsec;
wf_high = timespec64_to_ns(&ts_on);
ts_period.tv_sec = perout_request->period.sec;
ts_period.tv_nsec = perout_request->period.nsec;
period64 = timespec64_to_ns(&ts_period);

if (period64 < 200) {
netif_warn(adapter, drv, adapter->netdev,
"perout period too small, minimum is 200nS\n");
ret = -EOPNOTSUPP;
goto failed;
}
if (wf_high >= period64) {
netif_warn(adapter, drv, adapter->netdev,
"pulse width must be smaller than period\n");
ret = -EINVAL;
goto failed;
}

/* Check if we can do 50% toggle on an even value of period.
* If the period number is odd, then check if the requested
* pulse width is the same as one of pre-defined width values.
* Otherwise, return failure.
*/
half = div_s64_rem(period64, 2, &reminder);
if (!reminder) {
if (half == wf_high) {
/* It's 50% match. Use the toggle option */
pulse_width = PTP_GENERAL_CONFIG_CLOCK_EVENT_TOGGLE_;
/* In this case, devide period value by 2 */
ts_period = ns_to_timespec64(div_s64(period64, 2));
period_sec = ts_period.tv_sec;
period_nsec = ts_period.tv_nsec;

goto program;
}
}
/* if we can't do toggle, then the width option needs to be the exact match */
if (wf_high == 200000000) {
pulse_width = PTP_GENERAL_CONFIG_CLOCK_EVENT_200MS_;
} else if (period_nsec >= 20000000) {
} else if (wf_high == 10000000) {
pulse_width = PTP_GENERAL_CONFIG_CLOCK_EVENT_10MS_;
} else if (period_nsec >= 2000000) {
} else if (wf_high == 1000000) {
pulse_width = PTP_GENERAL_CONFIG_CLOCK_EVENT_1MS_;
} else if (period_nsec >= 200000) {
} else if (wf_high == 100000) {
pulse_width = PTP_GENERAL_CONFIG_CLOCK_EVENT_100US_;
} else if (period_nsec >= 20000) {
} else if (wf_high == 10000) {
pulse_width = PTP_GENERAL_CONFIG_CLOCK_EVENT_10US_;
} else if (period_nsec >= 200) {
} else if (wf_high == 100) {
pulse_width = PTP_GENERAL_CONFIG_CLOCK_EVENT_100NS_;
} else {
netif_warn(adapter, drv, adapter->netdev,
"perout period too small, minimum is 200nS\n");
"duty cycle specified is not supported\n");
ret = -EOPNOTSUPP;
goto failed;
}
} else {
pulse_width = PTP_GENERAL_CONFIG_CLOCK_EVENT_200MS_;
if (period_sec == 0) {
if (period_nsec >= 400000000) {
pulse_width = PTP_GENERAL_CONFIG_CLOCK_EVENT_200MS_;
} else if (period_nsec >= 20000000) {
pulse_width = PTP_GENERAL_CONFIG_CLOCK_EVENT_10MS_;
} else if (period_nsec >= 2000000) {
pulse_width = PTP_GENERAL_CONFIG_CLOCK_EVENT_1MS_;
} else if (period_nsec >= 200000) {
pulse_width = PTP_GENERAL_CONFIG_CLOCK_EVENT_100US_;
} else if (period_nsec >= 20000) {
pulse_width = PTP_GENERAL_CONFIG_CLOCK_EVENT_10US_;
} else if (period_nsec >= 200) {
pulse_width = PTP_GENERAL_CONFIG_CLOCK_EVENT_100NS_;
} else {
netif_warn(adapter, drv, adapter->netdev,
"perout period too small, minimum is 200nS\n");
ret = -EOPNOTSUPP;
goto failed;
}
} else {
pulse_width = PTP_GENERAL_CONFIG_CLOCK_EVENT_200MS_;
}
}
program:

/* turn off by setting target far in future */
lan743x_csr_write(adapter,
Expand Down Expand Up @@ -599,7 +668,7 @@ static int lan743x_ptp_perout(struct lan743x_adapter *adapter, int on,

failed:
lan743x_ptp_perout_off(adapter, index);
return -ENODEV;
return ret;
}

static int lan743x_ptpci_enable(struct ptp_clock_info *ptpci,
Expand Down

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