[PATCH net-next v4 2/2] net: ti: icss-iep: Add phase offset configuration for perout signal

[Meghana Malladi <m-malladi@ti.com>]

icss_iep_perout_enable_hw() is a common function for generating
both pps and perout signals. When enabling pps, the application needs
to only pass enable/disable argument, whereas for perout it supports
different flags to configure the signal.

In case the app passes a valid phase offset value, the signal should
start toggling after that phase offset, else start immediately or
as soon as possible. ICSS_IEP_SYNC_START_REG register take number of
clock cycles to wait before starting the signal after activation time.
Set appropriate value to this register to support phase offset.

Signed-off-by: Meghana Malladi <m-malladi@ti.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Kory Maincent <kory.maincent@bootlin.com>
---
Changes from v3 (v4-v3):
- Move flag checks out of mutex lock as suggested by Kory Maincent <kory.maincent@bootlin.com>
- Collected RB tag from Kory Maincent <kory.maincent@bootlin.com>

 drivers/net/ethernet/ti/icssg/icss_iep.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/ti/icssg/icss_iep.c b/drivers/net/ethernet/ti/icssg/icss_iep.c
index 2981c19c48b1..b4a34c57b7b4 100644
--- a/drivers/net/ethernet/ti/icssg/icss_iep.c
+++ b/drivers/net/ethernet/ti/icssg/icss_iep.c
@@ -407,6 +407,7 @@ static int icss_iep_perout_enable_hw(struct icss_iep *iep,
 				     struct ptp_perout_request *req, int on)
 {
 	struct timespec64 ts;
+	u64 ns_start;
 	u64 ns_width;
 	int ret;
 	u64 cmp;
@@ -416,6 +417,14 @@ static int icss_iep_perout_enable_hw(struct icss_iep *iep,
 	ts.tv_nsec = req->on.nsec;
 	ns_width = timespec64_to_ns(&ts);
 
+	if (req->flags & PTP_PEROUT_PHASE) {
+		ts.tv_sec = req->phase.sec;
+		ts.tv_nsec = req->phase.nsec;
+		ns_start = timespec64_to_ns(&ts);
+	} else {
+		ns_start = 0;
+	}
+
 	if (iep->ops && iep->ops->perout_enable) {
 		ret = iep->ops->perout_enable(iep->clockops_data, req, on, &cmp);
 		if (ret)
@@ -430,7 +439,8 @@ static int icss_iep_perout_enable_hw(struct icss_iep *iep,
 			regmap_write(iep->map, ICSS_IEP_SYNC_PWIDTH_REG,
 				     div_u64(ns_width, iep->def_inc));
 			regmap_write(iep->map, ICSS_IEP_SYNC0_PERIOD_REG, 0);
-			regmap_write(iep->map, ICSS_IEP_SYNC_START_REG, 0);
+			regmap_write(iep->map, ICSS_IEP_SYNC_START_REG,
+				     div_u64(ns_start, iep->def_inc));
 			regmap_write(iep->map, ICSS_IEP_SYNC_CTRL_REG, 0); /* one-shot mode */
 			/* Enable CMP 1 */
 			regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
@@ -457,6 +467,8 @@ static int icss_iep_perout_enable_hw(struct icss_iep *iep,
 
 			regmap_write(iep->map, ICSS_IEP_SYNC_PWIDTH_REG,
 				     div_u64(ns_width, iep->def_inc));
+			regmap_write(iep->map, ICSS_IEP_SYNC_START_REG,
+				     div_u64(ns_start, iep->def_inc));
 			/* Enable Sync in single shot mode  */
 			regmap_write(iep->map, ICSS_IEP_SYNC_CTRL_REG,
 				     IEP_SYNC_CTRL_SYNC_N_EN(0) | IEP_SYNC_CTRL_SYNC_EN);
@@ -487,7 +499,8 @@ static int icss_iep_perout_enable(struct icss_iep *iep,
 	int ret = 0;
 
 	/* Reject requests with unsupported flags */
-	if (req->flags & ~PTP_PEROUT_DUTY_CYCLE)
+	if (req->flags & ~(PTP_PEROUT_DUTY_CYCLE |
+			  PTP_PEROUT_PHASE))
 		return -EOPNOTSUPP;
 
 	mutex_lock(&iep->ptp_clk_mutex);
@@ -588,6 +601,7 @@ static int icss_iep_pps_enable(struct icss_iep *iep, int on)
 	if (on) {
 		ns = icss_iep_gettime(iep, NULL);
 		ts = ns_to_timespec64(ns);
+		rq.perout.flags = 0;
 		rq.perout.period.sec = 1;
 		rq.perout.period.nsec = 0;
 		rq.perout.start.sec = ts.tv_sec + 2;
-- 
2.43.0