[PATCH net-next v2 11/11] net: dsa: microchip: ksz9477: add periodic output support

Christian Eggers
2020-11-12T15:53:08Z

The KSZ9563 has a Trigger Output Unit (TOU) which can be used to
generate periodic signals.

The pulse length can be altered via a device attribute.

Tested on a Microchip KSZ9563 switch.

Signed-off-by: Christian Eggers <ceggers@arri.de>
---
drivers/net/dsa/microchip/ksz9477_ptp.c | 197 +++++++++++++++++++++++-
include/linux/dsa/ksz_common.h | 6 +
2 files changed, 202 insertions(+), 1 deletion(-)

diff --git a/drivers/net/dsa/microchip/ksz9477_ptp.c b/drivers/net/dsa/microchip/ksz9477_ptp.c
index 004bf43d33bf..1babacb9ee0d 100644
--- a/drivers/net/dsa/microchip/ksz9477_ptp.c
+++ b/drivers/net/dsa/microchip/ksz9477_ptp.c
@@ -90,6 +90,20 @@ static int ksz9477_ptp_tou_cycle_count_set(struct ksz_device *dev, u16 count)
return 0;
}

+static int ksz9477_ptp_tou_pulse_verify(u64 pulse_ns)
+{
+ u32 data;
+
+ if (pulse_ns & 0x3)
+ return -EINVAL;
+
+ data = (pulse_ns / 8);
+ if (data != (data & TRIG_PULSE_WIDTH_M))
+ return -ERANGE;
+
+ return 0;
+}
+
static int ksz9477_ptp_tou_pulse_set(struct ksz_device *dev, u32 pulse_ns)
{
u32 data;
@@ -191,6 +205,7 @@ static int ksz9477_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
return 0;
}

+static int ksz9477_ptp_restart_perout(struct ksz_device *dev);
static int ksz9477_ptp_enable_pps(struct ksz_device *dev, int on);

static int ksz9477_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
@@ -234,6 +249,15 @@ static int ksz9477_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
case KSZ_PTP_TOU_IDLE:
break;

+ case KSZ_PTP_TOU_PEROUT:
+ dev_info(dev->dev, "Restarting periodic output signal\n");
+
+ ret = ksz9477_ptp_restart_perout(dev);
+ if (ret)
+ goto error_return;
+
+ break;
+
case KSZ_PTP_TOU_PPS:
dev_info(dev->dev, "Restarting PPS\n");

@@ -348,6 +372,15 @@ static int ksz9477_ptp_settime(struct ptp_clock_info *ptp, struct timespec64 con
case KSZ_PTP_TOU_IDLE:
break;

+ case KSZ_PTP_TOU_PEROUT:
+ dev_info(dev->dev, "Restarting periodic output signal\n");
+
+ ret = ksz9477_ptp_restart_perout(dev);
+ if (ret)
+ goto error_return;
+
+ break;
+
case KSZ_PTP_TOU_PPS:
dev_info(dev->dev, "Restarting PPS\n");

@@ -367,6 +400,159 @@ static int ksz9477_ptp_settime(struct ptp_clock_info *ptp, struct timespec64 con
return ret;
}

+static int ksz9477_ptp_configure_perout(struct ksz_device *dev, u32 cycle_width_ns,
+ u16 cycle_count, u32 pulse_width_ns,
+ struct timespec64 const *target_time)
+{
+ int ret;
+ u32 trig_ctrl;
+
+ /* Enable notify, set rising edge, set periodic pattern */
+ trig_ctrl = TRIG_NOTIFY | (TRIG_POS_PERIOD << TRIG_PATTERN_S);
+ ret = ksz_write32(dev, REG_TRIG_CTRL__4, trig_ctrl);
+ if (ret)
+ return ret;
+
+ ret = ksz9477_ptp_tou_cycle_width_set(dev, cycle_width_ns);
+ if (ret)
+ return ret;
+
+ ksz9477_ptp_tou_cycle_count_set(dev, cycle_count);
+ if (ret)
+ return ret;
+
+ ret = ksz9477_ptp_tou_pulse_set(dev, pulse_width_ns);
+ if (ret)
+ return ret;
+
+ ret = ksz9477_ptp_tou_target_time_set(dev, target_time);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int ksz9477_ptp_enable_perout(struct ksz_device *dev,
+ struct ptp_perout_request const *perout_request, int on)
+{
+ u32 gpio_stat0;
+ u64 cycle_width_ns;
+ int ret;
+
+ if (dev->ptp_tou_mode != KSZ_PTP_TOU_PEROUT && dev->ptp_tou_mode != KSZ_PTP_TOU_IDLE)
+ return -EBUSY;
+
+ ret = ksz9477_ptp_tou_reset(dev, 0);
+ if (ret)
+ return ret;
+
+ if (!on) {
+ dev->ptp_tou_mode = KSZ_PTP_TOU_IDLE;
+ return 0; /* success */
+ }
+
+ dev->ptp_perout_target_time_first.tv_sec = perout_request->start.sec;
+ dev->ptp_perout_target_time_first.tv_nsec = perout_request->start.nsec;
+
+ dev->ptp_perout_period.tv_sec = perout_request->period.sec;
+ dev->ptp_perout_period.tv_nsec = perout_request->period.nsec;
+
+ cycle_width_ns = timespec64_to_ns(&dev->ptp_perout_period);
+ if ((cycle_width_ns & GENMASK(31, 0)) != cycle_width_ns)
+ return -EINVAL;
+
+ if (perout_request->flags & PTP_PEROUT_DUTY_CYCLE) {
+ u64 value = perout_request->on.sec * NSEC_PER_SEC +
+ perout_request->on.nsec;
+
+ ret = ksz9477_ptp_tou_pulse_verify(value);
+ if (ret)
+ return ret;
+
+ dev->ptp_perout_pulse_width_ns = value;
+ }
+
+ ret = ksz9477_ptp_configure_perout(dev, cycle_width_ns,
+ dev->ptp_perout_cycle_count,
+ dev->ptp_perout_pulse_width_ns,
+ &dev->ptp_perout_target_time_first);
+ if (ret)
+ return ret;
+
+ /* Activate trigger unit */
+ ret = ksz9477_ptp_tou_start(dev, NULL);
+ if (ret)
+ return ret;
+
+ /* Check error flag:
+ * - the ACTIVE flag is NOT cleared an error!
+ */
+ ret = ksz_read32(dev, REG_PTP_TRIG_STATUS__4, &gpio_stat0);
+ if (ret)
+ return ret;
+
+ if (gpio_stat0 & (1 << (0 + TRIG_ERROR_S))) {
+ dev_err(dev->dev, "%s: Trigger unit0 error!\n", __func__);
+ ret = -EIO;
+ /* Unit will be reset on next access */
+ return ret;
+ }
+
+ dev->ptp_tou_mode = KSZ_PTP_TOU_PEROUT;
+ return 0;
+}
+
+static int ksz9477_ptp_restart_perout(struct ksz_device *dev)
+{
+ struct timespec64 now;
+ s64 now_ns, first_ns, period_ns, next_ns;
+ unsigned int count;
+ int ret;
+
+ ret = _ksz9477_ptp_gettime(dev, &now);
+ if (ret)
+ return ret;
+
+ now_ns = timespec64_to_ns(&now);
+ first_ns = timespec64_to_ns(&dev->ptp_perout_target_time_first);
+
+ /* Calculate next perout event based on start time and period */
+ period_ns = timespec64_to_ns(&dev->ptp_perout_period);
+
+ if (first_ns < now_ns) {
+ count = div_u64(now_ns - first_ns, period_ns);
+ next_ns = first_ns + count * period_ns;
+ } else {
+ next_ns = first_ns;
+ }
+
+ /* Ensure 100 ms guard time prior next event */
+ while (next_ns < now_ns + 100000000)
+ next_ns += period_ns;
+
+ /* Restart periodic output signal */
+ {
+ struct timespec64 next = ns_to_timespec64(next_ns);
+ struct ptp_perout_request perout_request = {
+ .start = {
+ .sec = next.tv_sec,
+ .nsec = next.tv_nsec
+ },
+ .period = {
+ .sec = dev->ptp_perout_period.tv_sec,
+ .nsec = dev->ptp_perout_period.tv_nsec
+ },
+ .index = 0,
+ .flags = 0, /* keep current values */
+ };
+ ret = ksz9477_ptp_enable_perout(dev, &perout_request, 1);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
#define KSZ9477_PPS_TOU 0 /* currently fixed to trigger output unit 0 */

static int ksz9477_ptp_enable_pps(struct ksz_device *dev, int on)
@@ -457,6 +643,15 @@ static int ksz9477_ptp_enable(struct ptp_clock_info *ptp, struct ptp_clock_reque
int ret;

switch (req->type) {
+ case PTP_CLK_REQ_PEROUT:
+ {
+ struct ptp_perout_request const *perout_request = &req->perout;
+
+ mutex_lock(&dev->ptp_mutex);
+ ret = ksz9477_ptp_enable_perout(dev, perout_request, on);
+ mutex_unlock(&dev->ptp_mutex);
+ return ret;
+ }
case PTP_CLK_REQ_PPS:
mutex_lock(&dev->ptp_mutex);
ret = ksz9477_ptp_enable_pps(dev, on);
@@ -790,7 +985,7 @@ int ksz9477_ptp_init(struct ksz_device *dev)
dev->ptp_caps.max_adj = 6249999;
dev->ptp_caps.n_alarm = 0;
dev->ptp_caps.n_ext_ts = 0; /* currently not implemented */
- dev->ptp_caps.n_per_out = 0;
+ dev->ptp_caps.n_per_out = 1;
dev->ptp_caps.pps = 1;
dev->ptp_caps.adjfine = ksz9477_ptp_adjfine;
dev->ptp_caps.adjtime = ksz9477_ptp_adjtime;
diff --git a/include/linux/dsa/ksz_common.h b/include/linux/dsa/ksz_common.h
index 375f484ddb31..f5c3db50b60a 100644
--- a/include/linux/dsa/ksz_common.h
+++ b/include/linux/dsa/ksz_common.h
@@ -16,6 +16,7 @@
#include <linux/ptp_clock_kernel.h>
#include <linux/spinlock.h>
#include <linux/regmap.h>
+#include <linux/time64.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#include <net/dsa.h>
@@ -69,6 +70,7 @@ struct ksz_port {

enum ksz_ptp_tou_mode {
KSZ_PTP_TOU_IDLE,
+ KSZ_PTP_TOU_PEROUT,
KSZ_PTP_TOU_PPS,
};

@@ -131,6 +133,10 @@ struct ksz_device {
/* approximated current time, read once per second from hardware */
struct timespec64 ptp_clock_time;
enum ksz_ptp_tou_mode ptp_tou_mode;
+ struct timespec64 ptp_perout_target_time_first; /* start of first perout pulse */
+ struct timespec64 ptp_perout_period;
+ u32 ptp_perout_pulse_width_ns;
+ u16 ptp_perout_cycle_count;
#endif
};

--
Christian Eggers
Embedded software developer

Arnold & Richter Cine Technik GmbH & Co. Betriebs KG
Sitz: Muenchen - Registergericht: Amtsgericht Muenchen - Handelsregisternummer: HRA 57918
Persoenlich haftender Gesellschafter: Arnold & Richter Cine Technik GmbH
Sitz: Muenchen - Registergericht: Amtsgericht Muenchen - Handelsregisternummer: HRB 54477
Geschaeftsfuehrer: Dr. Michael Neuhaeuser; Stephan Schenk; Walter Trauninger; Markus Zeiler