Merge branch 'ptp-Add-adjust-phase-to-support-phase-offset'

Vincent Cheng says:

====================
ptp: Add adjust phase to support phase offset.

This series adds adjust phase to the PTP Hardware Clock device interface.

Some PTP hardware clocks have a write phase mode that has
a built-in hardware filtering capability.  The write phase mode
utilizes a phase offset control word instead of a frequency offset
control word.  Add adjust phase function to take advantage of this
capability.

Changes since v1:
- As suggested by Richard Cochran:
  1. ops->adjphase is new so need to check for non-null function pointer.
  2. Kernel coding style uses lower_case_underscores.
  3. Use existing PTP clock API for delayed worker.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/ptp/ptp_chardev.c

@@ -136,6 +136,7 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
 		caps.pps = ptp->info->pps;
 		caps.n_pins = ptp->info->n_pins;
 		caps.cross_timestamping = ptp->info->getcrosststamp != NULL;
+		caps.adjust_phase = ptp->info->adjphase != NULL;
 		if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
 			err = -EFAULT;
 		break;

drivers/ptp/ptp_clock.c

@@ -146,6 +146,9 @@ static int ptp_clock_adjtime(struct posix_clock *pc, struct __kernel_timex *tx)
 		else
 			err = ops->adjfreq(ops, ppb);
 		ptp->dialed_frequency = tx->freq;
+	} else if (tx->modes & ADJ_OFFSET) {
+		if (ops->adjphase)
+			err = ops->adjphase(ops, tx->offset);
 	} else if (tx->modes == 0) {
 		tx->freq = ptp->dialed_frequency;
 		err = 0;

drivers/ptp/ptp_clockmatrix.c

@@ -10,6 +10,7 @@
 #include <linux/module.h>
 #include <linux/ptp_clock_kernel.h>
 #include <linux/delay.h>
+#include <linux/jiffies.h>
 #include <linux/kernel.h>
 #include <linux/timekeeping.h>
 
@@ -24,6 +25,16 @@ MODULE_LICENSE("GPL");
 
 #define SETTIME_CORRECTION (0)
 
+static long set_write_phase_ready(struct ptp_clock_info *ptp)
+{
+	struct idtcm_channel *channel =
+		container_of(ptp, struct idtcm_channel, caps);
+
+	channel->write_phase_ready = 1;
+
+	return 0;
+}
+
 static int char_array_to_timespec(u8 *buf,
 				  u8 count,
 				  struct timespec64 *ts)
@@ -871,6 +882,64 @@ static int idtcm_set_pll_mode(struct idtcm_channel *channel,
 
 /* PTP Hardware Clock interface */
 
+/**
+ * @brief Maximum absolute value for write phase offset in picoseconds
+ *
+ * Destination signed register is 32-bit register in resolution of 50ps
+ *
+ * 0x7fffffff * 50 =  2147483647 * 50 = 107374182350
+ */
+static int _idtcm_adjphase(struct idtcm_channel *channel, s32 delta_ns)
+{
+	struct idtcm *idtcm = channel->idtcm;
+
+	int err;
+	u8 i;
+	u8 buf[4] = {0};
+	s32 phase_50ps;
+	s64 offset_ps;
+
+	if (channel->pll_mode != PLL_MODE_WRITE_PHASE) {
+
+		err = idtcm_set_pll_mode(channel, PLL_MODE_WRITE_PHASE);
+
+		if (err)
+			return err;
+
+		channel->write_phase_ready = 0;
+
+		ptp_schedule_worker(channel->ptp_clock,
+				    msecs_to_jiffies(WR_PHASE_SETUP_MS));
+	}
+
+	if (!channel->write_phase_ready)
+		delta_ns = 0;
+
+	offset_ps = (s64)delta_ns * 1000;
+
+	/*
+	 * Check for 32-bit signed max * 50:
+	 *
+	 * 0x7fffffff * 50 =  2147483647 * 50 = 107374182350
+	 */
+	if (offset_ps > MAX_ABS_WRITE_PHASE_PICOSECONDS)
+		offset_ps = MAX_ABS_WRITE_PHASE_PICOSECONDS;
+	else if (offset_ps < -MAX_ABS_WRITE_PHASE_PICOSECONDS)
+		offset_ps = -MAX_ABS_WRITE_PHASE_PICOSECONDS;
+
+	phase_50ps = DIV_ROUND_CLOSEST(div64_s64(offset_ps, 50), 1);
+
+	for (i = 0; i < 4; i++) {
+		buf[i] = phase_50ps & 0xff;
+		phase_50ps >>= 8;
+	}
+
+	err = idtcm_write(idtcm, channel->dpll_phase, DPLL_WR_PHASE,
+			  buf, sizeof(buf));
+
+	return err;
+}
+
 static int idtcm_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
 {
 	struct idtcm_channel *channel =
@@ -977,6 +1046,24 @@ static int idtcm_adjtime(struct ptp_clock_info *ptp, s64 delta)
 	return err;
 }
 
+static int idtcm_adjphase(struct ptp_clock_info *ptp, s32 delta)
+{
+	struct idtcm_channel *channel =
+		container_of(ptp, struct idtcm_channel, caps);
+
+	struct idtcm *idtcm = channel->idtcm;
+
+	int err;
+
+	mutex_lock(&idtcm->reg_lock);
+
+	err = _idtcm_adjphase(channel, delta);
+
+	mutex_unlock(&idtcm->reg_lock);
+
+	return err;
+}
+
 static int idtcm_enable(struct ptp_clock_info *ptp,
 			struct ptp_clock_request *rq, int on)
 {
@@ -1055,13 +1142,16 @@ static const struct ptp_clock_info idtcm_caps = {
 	.owner		= THIS_MODULE,
 	.max_adj	= 244000,
 	.n_per_out	= 1,
+	.adjphase	= &idtcm_adjphase,
 	.adjfreq	= &idtcm_adjfreq,
 	.adjtime	= &idtcm_adjtime,
 	.gettime64	= &idtcm_gettime,
 	.settime64	= &idtcm_settime,
 	.enable		= &idtcm_enable,
+	.do_aux_work	= &set_write_phase_ready,
 };
 
+
 static int idtcm_enable_channel(struct idtcm *idtcm, u32 index)
 {
 	struct idtcm_channel *channel;
@@ -1146,6 +1236,8 @@ static int idtcm_enable_channel(struct idtcm *idtcm, u32 index)
 	if (!channel->ptp_clock)
 		return -ENOTSUPP;
 
+	channel->write_phase_ready = 0;
+
 	dev_info(&idtcm->client->dev, "PLL%d registered as ptp%d\n",
 		 index, channel->ptp_clock->index);
 

drivers/ptp/ptp_clockmatrix.h

@@ -15,6 +15,8 @@
 #define FW_FILENAME	"idtcm.bin"
 #define MAX_PHC_PLL	4
 
+#define MAX_ABS_WRITE_PHASE_PICOSECONDS (107374182350LL)
+
 #define PLL_MASK_ADDR		(0xFFA5)
 #define DEFAULT_PLL_MASK	(0x04)
 
@@ -35,6 +37,7 @@
 #define PHASE_PULL_IN_THRESHOLD_NS	(150000)
 #define TOD_WRITE_OVERHEAD_COUNT_MAX	(5)
 #define TOD_BYTE_COUNT			(11)
+#define WR_PHASE_SETUP_MS		(5000)
 
 /* Values of DPLL_N.DPLL_MODE.PLL_MODE */
 enum pll_mode {
@@ -77,6 +80,7 @@ struct idtcm_channel {
 	u16			hw_dpll_n;
 	enum pll_mode		pll_mode;
 	u16			output_mask;
+	int			write_phase_ready;
 };
 
 struct idtcm {

include/linux/ptp_clock_kernel.h

@@ -36,7 +36,7 @@ struct ptp_system_timestamp {
 };
 
 /**
- * struct ptp_clock_info - decribes a PTP hardware clock
+ * struct ptp_clock_info - describes a PTP hardware clock
  *
  * @owner:     The clock driver should set to THIS_MODULE.
  * @name:      A short "friendly name" to identify the clock and to
@@ -65,6 +65,9 @@ struct ptp_system_timestamp {
  *            parameter delta: Desired frequency offset from nominal frequency
  *            in parts per billion
  *
+ * @adjphase:  Adjusts the phase offset of the hardware clock.
+ *             parameter delta: Desired change in nanoseconds.
+ *
  * @adjtime:  Shifts the time of the hardware clock.
  *            parameter delta: Desired change in nanoseconds.
  *
@@ -128,6 +131,7 @@ struct ptp_clock_info {
 	struct ptp_pin_desc *pin_config;
 	int (*adjfine)(struct ptp_clock_info *ptp, long scaled_ppm);
 	int (*adjfreq)(struct ptp_clock_info *ptp, s32 delta);
+	int (*adjphase)(struct ptp_clock_info *ptp, s32 phase);
 	int (*adjtime)(struct ptp_clock_info *ptp, s64 delta);
 	int (*gettime64)(struct ptp_clock_info *ptp, struct timespec64 *ts);
 	int (*gettimex64)(struct ptp_clock_info *ptp, struct timespec64 *ts,

include/uapi/linux/ptp_clock.h

@@ -89,7 +89,9 @@ struct ptp_clock_caps {
 	int n_pins;    /* Number of input/output pins. */
 	/* Whether the clock supports precise system-device cross timestamps */
 	int cross_timestamping;
-	int rsv[13];   /* Reserved for future use. */
+	/* Whether the clock supports adjust phase */
+	int adjust_phase;
+	int rsv[12];   /* Reserved for future use. */
 };
 
 struct ptp_extts_request {

tools/testing/selftests/ptp/testptp.c

@@ -269,14 +269,16 @@ int main(int argc, char *argv[])
 			       "  %d programmable periodic signals\n"
 			       "  %d pulse per second\n"
 			       "  %d programmable pins\n"
-			       "  %d cross timestamping\n",
+			       "  %d cross timestamping\n"
+			       "  %d adjust_phase\n",
 			       caps.max_adj,
 			       caps.n_alarm,
 			       caps.n_ext_ts,
 			       caps.n_per_out,
 			       caps.pps,
 			       caps.n_pins,
-			       caps.cross_timestamping);
+			       caps.cross_timestamping,
+			       caps.adjust_phase);
 		}
 	}