net: dsa: microchip: ptp: add support for perout programmable pins

There are two programmable pins available for Trigger output unit to
generate periodic pulses. This patch add verify_pin for the available 2
pins and configure it with respect to GPIO index for the TOU unit.

Tested using testptp
./testptp -i 0 -L 0,2
./testptp -i 0 -d /dev/ptp0 -p 1000000000
./testptp -i 1 -L 1,2
./testptp -i 1 -d /dev/ptp0 -p 100000000

Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/microchip/ksz_ptp.c

@@ -171,6 +171,10 @@ static int ksz_ptp_enable_perout(struct ksz_device *dev,
 	    ptp_data->tou_mode != KSZ_PTP_TOU_IDLE)
 		return -EBUSY;
 
+	pin = ptp_find_pin(ptp_data->clock, PTP_PF_PEROUT, request->index);
+	if (pin < 0)
+		return -EINVAL;
+
 	data32 = FIELD_PREP(PTP_GPIO_INDEX, pin) |
 		 FIELD_PREP(PTP_TOU_INDEX, request->index);
 	ret = ksz_rmw32(dev, REG_PTP_UNIT_INDEX__4,
@@ -779,6 +783,23 @@ static int ksz_ptp_enable(struct ptp_clock_info *ptp,
 	return ret;
 }
 
+static int ksz_ptp_verify_pin(struct ptp_clock_info *ptp, unsigned int pin,
+			      enum ptp_pin_function func, unsigned int chan)
+{
+	int ret = 0;
+
+	switch (func) {
+	case PTP_PF_NONE:
+	case PTP_PF_PEROUT:
+		break;
+	default:
+		ret = -1;
+		break;
+	}
+
+	return ret;
+}
+
 /*  Function is pointer to the do_aux_work in the ptp_clock capability */
 static long ksz_ptp_do_aux_work(struct ptp_clock_info *ptp)
 {
@@ -822,6 +843,7 @@ int ksz_ptp_clock_register(struct dsa_switch *ds)
 	struct ksz_device *dev = ds->priv;
 	struct ksz_ptp_data *ptp_data;
 	int ret;
+	u8 i;
 
 	ptp_data = &dev->ptp_data;
 	mutex_init(&ptp_data->lock);
@@ -836,12 +858,25 @@ int ksz_ptp_clock_register(struct dsa_switch *ds)
 	ptp_data->caps.adjtime		= ksz_ptp_adjtime;
 	ptp_data->caps.do_aux_work	= ksz_ptp_do_aux_work;
 	ptp_data->caps.enable		= ksz_ptp_enable;
+	ptp_data->caps.verify		= ksz_ptp_verify_pin;
+	ptp_data->caps.n_pins		= KSZ_PTP_N_GPIO;
 	ptp_data->caps.n_per_out	= 3;
 
 	ret = ksz_ptp_start_clock(dev);
 	if (ret)
 		return ret;
 
+	for (i = 0; i < KSZ_PTP_N_GPIO; i++) {
+		struct ptp_pin_desc *ptp_pin = &ptp_data->pin_config[i];
+
+		snprintf(ptp_pin->name,
+			 sizeof(ptp_pin->name), "ksz_ptp_pin_%02d", i);
+		ptp_pin->index = i;
+		ptp_pin->func = PTP_PF_NONE;
+	}
+
+	ptp_data->caps.pin_config = ptp_data->pin_config;
+
 	/* Currently only P2P mode is supported. When 802_1AS bit is set, it
 	 * forwards all PTP packets to host port and none to other ports.
 	 */

drivers/net/dsa/microchip/ksz_ptp.h

@@ -12,6 +12,8 @@
 
 #include <linux/ptp_clock_kernel.h>
 
+#define KSZ_PTP_N_GPIO		2
+
 enum ksz_ptp_tou_mode {
 	KSZ_PTP_TOU_IDLE,
 	KSZ_PTP_TOU_PEROUT,
@@ -20,6 +22,7 @@ enum ksz_ptp_tou_mode {
 struct ksz_ptp_data {
 	struct ptp_clock_info caps;
 	struct ptp_clock *clock;
+	struct ptp_pin_desc pin_config[KSZ_PTP_N_GPIO];
 	/* Serializes all operations on the PTP hardware clock */
 	struct mutex lock;
 	/* lock for accessing the clock_time */