net: phy: micrel: Add support for PTP_PF_PEROUT for lan8841

Lan8841 has 10 GPIOs and it has 2 events(EVENT_A and EVENT_B). It is
possible to assigned the 2 events to any of the GPIOs, but a GPIO can
have only 1 event at a time.
These events are used to generate periodic signals. It is possible to
configure the length, the start time and the period of the signal by
configuring the event.
Currently the SW uses only EVENT_A to generate the perout.

These events are generated by comparing the target time with the PHC
time. In case the PHC time is changed to a value bigger than the target
time + reload time, then it would generate only 1 event and then it
would stop because target time + reload time is small than PHC time.
Therefore it is required to change also the target time every time when
the PHC is changed. The same will apply also when the PHC time is
changed to a smaller value.

This was tested using:
testptp -L 6,2
testptp -p 1000000000 -w 200000000
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Link: https://lore.kernel.org/r/20230307214402.793057-1-horatiu.vultur@microchip.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/phy/micrel.c

@@ -318,6 +318,7 @@ struct kszphy_ptp_priv {
 	struct ptp_clock_info ptp_clock_info;
 	/* Lock for ptp_clock */
 	struct mutex ptp_lock;
+	struct ptp_pin_desc *pin_config;
 };
 
 struct kszphy_priv {
@@ -3658,6 +3659,77 @@ static int lan8841_hwtstamp(struct mii_timestamper *mii_ts, struct ifreq *ifr)
 	return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ? -EFAULT : 0;
 }
 
+#define LAN8841_EVENT_A		0
+#define LAN8841_EVENT_B		1
+#define LAN8841_PTP_LTC_TARGET_SEC_HI(event)	((event) == LAN8841_EVENT_A ? 278 : 288)
+#define LAN8841_PTP_LTC_TARGET_SEC_LO(event)	((event) == LAN8841_EVENT_A ? 279 : 289)
+#define LAN8841_PTP_LTC_TARGET_NS_HI(event)	((event) == LAN8841_EVENT_A ? 280 : 290)
+#define LAN8841_PTP_LTC_TARGET_NS_LO(event)	((event) == LAN8841_EVENT_A ? 281 : 291)
+
+static int lan8841_ptp_set_target(struct kszphy_ptp_priv *ptp_priv, u8 event,
+				  s64 sec, u32 nsec)
+{
+	struct phy_device *phydev = ptp_priv->phydev;
+	int ret;
+
+	ret = phy_write_mmd(phydev, 2, LAN8841_PTP_LTC_TARGET_SEC_HI(event),
+			    upper_16_bits(sec));
+	if (ret)
+		return ret;
+
+	ret = phy_write_mmd(phydev, 2, LAN8841_PTP_LTC_TARGET_SEC_LO(event),
+			    lower_16_bits(sec));
+	if (ret)
+		return ret;
+
+	ret = phy_write_mmd(phydev, 2, LAN8841_PTP_LTC_TARGET_NS_HI(event) & 0x3fff,
+			    upper_16_bits(nsec));
+	if (ret)
+		return ret;
+
+	return phy_write_mmd(phydev, 2, LAN8841_PTP_LTC_TARGET_NS_LO(event),
+			    lower_16_bits(nsec));
+}
+
+#define LAN8841_BUFFER_TIME	2
+
+static int lan8841_ptp_update_target(struct kszphy_ptp_priv *ptp_priv,
+				     const struct timespec64 *ts)
+{
+	return lan8841_ptp_set_target(ptp_priv, LAN8841_EVENT_A,
+				      ts->tv_sec + LAN8841_BUFFER_TIME, ts->tv_nsec);
+}
+
+#define LAN8841_PTP_LTC_TARGET_RELOAD_SEC_HI(event)	((event) == LAN8841_EVENT_A ? 282 : 292)
+#define LAN8841_PTP_LTC_TARGET_RELOAD_SEC_LO(event)	((event) == LAN8841_EVENT_A ? 283 : 293)
+#define LAN8841_PTP_LTC_TARGET_RELOAD_NS_HI(event)	((event) == LAN8841_EVENT_A ? 284 : 294)
+#define LAN8841_PTP_LTC_TARGET_RELOAD_NS_LO(event)	((event) == LAN8841_EVENT_A ? 285 : 295)
+
+static int lan8841_ptp_set_reload(struct kszphy_ptp_priv *ptp_priv, u8 event,
+				  s64 sec, u32 nsec)
+{
+	struct phy_device *phydev = ptp_priv->phydev;
+	int ret;
+
+	ret = phy_write_mmd(phydev, 2, LAN8841_PTP_LTC_TARGET_RELOAD_SEC_HI(event),
+			    upper_16_bits(sec));
+	if (ret)
+		return ret;
+
+	ret = phy_write_mmd(phydev, 2, LAN8841_PTP_LTC_TARGET_RELOAD_SEC_LO(event),
+			    lower_16_bits(sec));
+	if (ret)
+		return ret;
+
+	ret = phy_write_mmd(phydev, 2, LAN8841_PTP_LTC_TARGET_RELOAD_NS_HI(event) & 0x3fff,
+			    upper_16_bits(nsec));
+	if (ret)
+		return ret;
+
+	return phy_write_mmd(phydev, 2, LAN8841_PTP_LTC_TARGET_RELOAD_NS_LO(event),
+			     lower_16_bits(nsec));
+}
+
 #define LAN8841_PTP_LTC_SET_SEC_HI	262
 #define LAN8841_PTP_LTC_SET_SEC_MID	263
 #define LAN8841_PTP_LTC_SET_SEC_LO	264
@@ -3671,6 +3743,7 @@ static int lan8841_ptp_settime64(struct ptp_clock_info *ptp,
 	struct kszphy_ptp_priv *ptp_priv = container_of(ptp, struct kszphy_ptp_priv,
 							ptp_clock_info);
 	struct phy_device *phydev = ptp_priv->phydev;
+	int ret;
 
 	/* Set the value to be stored */
 	mutex_lock(&ptp_priv->ptp_lock);
@@ -3683,9 +3756,10 @@ static int lan8841_ptp_settime64(struct ptp_clock_info *ptp,
 	/* Set the command to load the LTC */
 	phy_write_mmd(phydev, 2, LAN8841_PTP_CMD_CTL,
 		      LAN8841_PTP_CMD_CTL_PTP_LTC_LOAD);
+	ret = lan8841_ptp_update_target(ptp_priv, ts);
 	mutex_unlock(&ptp_priv->ptp_lock);
 
-	return 0;
+	return ret;
 }
 
 #define LAN8841_PTP_LTC_RD_SEC_HI	358
@@ -3740,6 +3814,7 @@ static int lan8841_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
 	bool add = true;
 	u32 nsec;
 	s32 sec;
+	int ret;
 
 	/* The HW allows up to 15 sec to adjust the time, but here we limit to
 	 * 10 sec the adjustment. The reason is, in case the adjustment is 14
@@ -3803,7 +3878,13 @@ static int lan8841_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
 	}
 	mutex_unlock(&ptp_priv->ptp_lock);
 
-	return 0;
+	/* Update the target clock */
+	ptp->gettime64(ptp, &ts);
+	mutex_lock(&ptp_priv->ptp_lock);
+	ret = lan8841_ptp_update_target(ptp_priv, &ts);
+	mutex_unlock(&ptp_priv->ptp_lock);
+
+	return ret;
 }
 
 #define LAN8841_PTP_LTC_RATE_ADJ_HI		269
@@ -3839,6 +3920,292 @@ static int lan8841_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
 	return 0;
 }
 
+static int lan8841_ptp_verify(struct ptp_clock_info *ptp, unsigned int pin,
+			      enum ptp_pin_function func, unsigned int chan)
+{
+	switch (func) {
+	case PTP_PF_NONE:
+	case PTP_PF_PEROUT:
+		break;
+	default:
+		return -1;
+	}
+
+	return 0;
+}
+
+#define LAN8841_PTP_GPIO_NUM	10
+#define LAN8841_GPIO_EN		128
+#define LAN8841_GPIO_DIR	129
+#define LAN8841_GPIO_BUF	130
+
+static int lan8841_ptp_perout_off(struct kszphy_ptp_priv *ptp_priv, int pin)
+{
+	struct phy_device *phydev = ptp_priv->phydev;
+	int ret;
+
+	ret = phy_clear_bits_mmd(phydev, 2, LAN8841_GPIO_EN, BIT(pin));
+	if (ret)
+		return ret;
+
+	ret = phy_clear_bits_mmd(phydev, 2, LAN8841_GPIO_DIR, BIT(pin));
+	if (ret)
+		return ret;
+
+	return phy_clear_bits_mmd(phydev, 2, LAN8841_GPIO_BUF, BIT(pin));
+}
+
+static int lan8841_ptp_perout_on(struct kszphy_ptp_priv *ptp_priv, int pin)
+{
+	struct phy_device *phydev = ptp_priv->phydev;
+	int ret;
+
+	ret = phy_set_bits_mmd(phydev, 2, LAN8841_GPIO_EN, BIT(pin));
+	if (ret)
+		return ret;
+
+	ret = phy_set_bits_mmd(phydev, 2, LAN8841_GPIO_DIR, BIT(pin));
+	if (ret)
+		return ret;
+
+	return phy_set_bits_mmd(phydev, 2, LAN8841_GPIO_BUF, BIT(pin));
+}
+
+#define LAN8841_GPIO_DATA_SEL1				131
+#define LAN8841_GPIO_DATA_SEL2				132
+#define LAN8841_GPIO_DATA_SEL_GPIO_DATA_SEL_EVENT_MASK	GENMASK(2, 0)
+#define LAN8841_GPIO_DATA_SEL_GPIO_DATA_SEL_EVENT_A	1
+#define LAN8841_GPIO_DATA_SEL_GPIO_DATA_SEL_EVENT_B	2
+#define LAN8841_PTP_GENERAL_CONFIG			257
+#define LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_POL_A	BIT(1)
+#define LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_POL_B	BIT(3)
+#define LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_A_MASK	GENMASK(7, 4)
+#define LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_B_MASK	GENMASK(11, 8)
+#define LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_A		4
+#define LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_B		7
+
+static int lan8841_ptp_remove_event(struct kszphy_ptp_priv *ptp_priv, int pin,
+				    u8 event)
+{
+	struct phy_device *phydev = ptp_priv->phydev;
+	u16 tmp;
+	int ret;
+
+	/* Now remove pin from the event. GPIO_DATA_SEL1 contains the GPIO
+	 * pins 0-4 while GPIO_DATA_SEL2 contains GPIO pins 5-9, therefore
+	 * depending on the pin, it requires to read a different register
+	 */
+	if (pin < 5) {
+		tmp = LAN8841_GPIO_DATA_SEL_GPIO_DATA_SEL_EVENT_MASK << (3 * pin);
+		ret = phy_clear_bits_mmd(phydev, 2, LAN8841_GPIO_DATA_SEL1, tmp);
+	} else {
+		tmp = LAN8841_GPIO_DATA_SEL_GPIO_DATA_SEL_EVENT_MASK << (3 * (pin - 5));
+		ret = phy_clear_bits_mmd(phydev, 2, LAN8841_GPIO_DATA_SEL2, tmp);
+	}
+	if (ret)
+		return ret;
+
+	/* Disable the event */
+	if (event == LAN8841_EVENT_A)
+		tmp = LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_POL_A |
+		      LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_A_MASK;
+	else
+		tmp = LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_POL_B |
+		      LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_B_MASK;
+	return phy_clear_bits_mmd(phydev, 2, LAN8841_GPIO_EN, tmp);
+}
+
+static int lan8841_ptp_enable_event(struct kszphy_ptp_priv *ptp_priv, int pin,
+				    u8 event, int pulse_width)
+{
+	struct phy_device *phydev = ptp_priv->phydev;
+	u16 tmp;
+	int ret;
+
+	/* Enable the event */
+	if (event == LAN8841_EVENT_A)
+		ret = phy_modify_mmd(phydev, 2, LAN8841_PTP_GENERAL_CONFIG,
+				     LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_POL_A |
+				     LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_A_MASK,
+				     LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_POL_A |
+				     pulse_width << LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_A);
+	else
+		ret = phy_modify_mmd(phydev, 2, LAN8841_PTP_GENERAL_CONFIG,
+				     LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_POL_B |
+				     LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_B_MASK,
+				     LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_POL_B |
+				     pulse_width << LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_B);
+	if (ret)
+		return ret;
+
+	/* Now connect the pin to the event. GPIO_DATA_SEL1 contains the GPIO
+	 * pins 0-4 while GPIO_DATA_SEL2 contains GPIO pins 5-9, therefore
+	 * depending on the pin, it requires to read a different register
+	 */
+	if (event == LAN8841_EVENT_A)
+		tmp = LAN8841_GPIO_DATA_SEL_GPIO_DATA_SEL_EVENT_A;
+	else
+		tmp = LAN8841_GPIO_DATA_SEL_GPIO_DATA_SEL_EVENT_B;
+
+	if (pin < 5)
+		ret = phy_set_bits_mmd(phydev, 2, LAN8841_GPIO_DATA_SEL1,
+				       tmp << (3 * pin));
+	else
+		ret = phy_set_bits_mmd(phydev, 2, LAN8841_GPIO_DATA_SEL2,
+				       tmp << (3 * (pin - 5)));
+
+	return ret;
+}
+
+#define LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_200MS	13
+#define LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_100MS	12
+#define LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_50MS	11
+#define LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_10MS	10
+#define LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_5MS	9
+#define LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_1MS	8
+#define LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_500US	7
+#define LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_100US	6
+#define LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_50US	5
+#define LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_10US	4
+#define LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_5US	3
+#define LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_1US	2
+#define LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_500NS	1
+#define LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_100NS	0
+
+static int lan8841_ptp_perout(struct ptp_clock_info *ptp,
+			      struct ptp_clock_request *rq, int on)
+{
+	struct kszphy_ptp_priv *ptp_priv = container_of(ptp, struct kszphy_ptp_priv,
+							ptp_clock_info);
+	struct phy_device *phydev = ptp_priv->phydev;
+	struct timespec64 ts_on, ts_period;
+	s64 on_nsec, period_nsec;
+	int pulse_width;
+	int pin;
+	int ret;
+
+	if (rq->perout.flags & ~PTP_PEROUT_DUTY_CYCLE)
+		return -EOPNOTSUPP;
+
+	pin = ptp_find_pin(ptp_priv->ptp_clock, PTP_PF_PEROUT, rq->perout.index);
+	if (pin == -1 || pin >= LAN8841_PTP_GPIO_NUM)
+		return -EINVAL;
+
+	if (!on) {
+		ret = lan8841_ptp_perout_off(ptp_priv, pin);
+		if (ret)
+			return ret;
+
+		return lan8841_ptp_remove_event(ptp_priv, LAN8841_EVENT_A, pin);
+	}
+
+	ts_on.tv_sec = rq->perout.on.sec;
+	ts_on.tv_nsec = rq->perout.on.nsec;
+	on_nsec = timespec64_to_ns(&ts_on);
+
+	ts_period.tv_sec = rq->perout.period.sec;
+	ts_period.tv_nsec = rq->perout.period.nsec;
+	period_nsec = timespec64_to_ns(&ts_period);
+
+	if (period_nsec < 200) {
+		pr_warn_ratelimited("%s: perout period too small, minimim is 200 nsec\n",
+				    phydev_name(phydev));
+		return -EOPNOTSUPP;
+	}
+
+	if (on_nsec >= period_nsec) {
+		pr_warn_ratelimited("%s: pulse width must be smaller than period\n",
+				    phydev_name(phydev));
+		return -EINVAL;
+	}
+
+	switch (on_nsec) {
+	case 200000000:
+		pulse_width = LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_200MS;
+		break;
+	case 100000000:
+		pulse_width = LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_100MS;
+		break;
+	case 50000000:
+		pulse_width = LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_50MS;
+		break;
+	case 10000000:
+		pulse_width = LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_10MS;
+		break;
+	case 5000000:
+		pulse_width = LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_5MS;
+		break;
+	case 1000000:
+		pulse_width = LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_1MS;
+		break;
+	case 500000:
+		pulse_width = LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_500US;
+		break;
+	case 100000:
+		pulse_width = LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_100US;
+		break;
+	case 50000:
+		pulse_width = LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_50US;
+		break;
+	case 10000:
+		pulse_width = LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_10US;
+		break;
+	case 5000:
+		pulse_width = LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_5US;
+		break;
+	case 1000:
+		pulse_width = LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_1US;
+		break;
+	case 500:
+		pulse_width = LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_500NS;
+		break;
+	case 100:
+		pulse_width = LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_100NS;
+		break;
+	default:
+		pr_warn_ratelimited("%s: Use default duty cycle of 100ns\n",
+				    phydev_name(phydev));
+		pulse_width = LAN8841_PTP_GENERAL_CONFIG_LTC_EVENT_100NS;
+		break;
+	}
+
+	mutex_lock(&ptp_priv->ptp_lock);
+	ret = lan8841_ptp_set_target(ptp_priv, LAN8841_EVENT_A, rq->perout.start.sec,
+				     rq->perout.start.nsec);
+	mutex_unlock(&ptp_priv->ptp_lock);
+	if (ret)
+		return ret;
+
+	ret = lan8841_ptp_set_reload(ptp_priv, LAN8841_EVENT_A, rq->perout.period.sec,
+				     rq->perout.period.nsec);
+	if (ret)
+		return ret;
+
+	ret = lan8841_ptp_enable_event(ptp_priv, pin, LAN8841_EVENT_A,
+				       pulse_width);
+	if (ret)
+		return ret;
+
+	ret = lan8841_ptp_perout_on(ptp_priv, pin);
+	if (ret)
+		lan8841_ptp_remove_event(ptp_priv, pin, LAN8841_EVENT_A);
+
+	return ret;
+}
+
+static int lan8841_ptp_enable(struct ptp_clock_info *ptp,
+			      struct ptp_clock_request *rq, int on)
+{
+	switch (rq->type) {
+	case PTP_CLK_REQ_PEROUT:
+		return lan8841_ptp_perout(ptp, rq, on);
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
 static struct ptp_clock_info lan8841_ptp_clock_info = {
 	.owner		= THIS_MODULE,
 	.name		= "lan8841 ptp",
@@ -3847,6 +4214,10 @@ static struct ptp_clock_info lan8841_ptp_clock_info = {
 	.settime64	= lan8841_ptp_settime64,
 	.adjtime	= lan8841_ptp_adjtime,
 	.adjfine	= lan8841_ptp_adjfine,
+	.verify         = lan8841_ptp_verify,
+	.enable         = lan8841_ptp_enable,
+	.n_per_out      = LAN8841_PTP_GPIO_NUM,
+	.n_pins         = LAN8841_PTP_GPIO_NUM,
 };
 
 #define LAN8841_OPERATION_MODE_STRAP_LOW_REGISTER 3
@@ -3874,7 +4245,23 @@ static int lan8841_probe(struct phy_device *phydev)
 	priv = phydev->priv;
 	ptp_priv = &priv->ptp_priv;
 
+	ptp_priv->pin_config = devm_kcalloc(&phydev->mdio.dev,
+					    LAN8841_PTP_GPIO_NUM,
+					    sizeof(*ptp_priv->pin_config),
+					    GFP_KERNEL);
+	if (!ptp_priv->pin_config)
+		return -ENOMEM;
+
+	for (int i = 0; i < LAN8841_PTP_GPIO_NUM; ++i) {
+		struct ptp_pin_desc *p = &ptp_priv->pin_config[i];
+
+		snprintf(p->name, sizeof(p->name), "pin%d", i);
+		p->index = i;
+		p->func = PTP_PF_NONE;
+	}
+
 	ptp_priv->ptp_clock_info = lan8841_ptp_clock_info;
+	ptp_priv->ptp_clock_info.pin_config = ptp_priv->pin_config;
 	ptp_priv->ptp_clock = ptp_clock_register(&ptp_priv->ptp_clock_info,
 						 &phydev->mdio.dev);
 	if (IS_ERR(ptp_priv->ptp_clock)) {