Merge branch 'PTP_CLK-pin-configuration-for-SJA1105-DSA-driver'

Vladimir Oltean says:

====================
PTP_CLK pin configuration for SJA1105 DSA driver

This series adds support for the PTP_CLK pin on SJA1105 to be configured
via the PTP subsystem, in the "periodic output" and "external timestamp
input" modes.
====================

Signed-off-by: David S. Miller <[e-mail]>

drivers/net/dsa/sja1105/sja1105.h

···
 	u64 config;
 	u64 sgmii;
 	u64 rmii_pll1;
+	u64 ptppinst;
+	u64 ptppindur;
 	u64 ptp_control;
 	u64 ptpclkval;
 	u64 ptpclkrate;
 	u64 ptpclkcorp;
+	u64 ptpsyncts;
 	u64 ptpschtm;
 	u64 ptpegr_ts[SJA1105_NUM_PORTS];
 	u64 pad_mii_tx[SJA1105_NUM_PORTS];
···
 size_t sja1105_vlan_lookup_entry_packing(void *buf, void *entry_ptr,
 					 enum packing_op op);
 size_t sja1105pqrs_mac_config_entry_packing(void *buf, void *entry_ptr,
+					    enum packing_op op);
+size_t sja1105pqrs_avb_params_entry_packing(void *buf, void *entry_ptr,
 					    enum packing_op op);
 
 #endif

drivers/net/dsa/sja1105/sja1105_dynamic_config.c

···
 #define SJA1105ET_SIZE_GENERAL_PARAMS_DYN_CMD			\
 	SJA1105_SIZE_DYN_CMD
 
+#define SJA1105PQRS_SIZE_AVB_PARAMS_DYN_CMD			\
+	(SJA1105_SIZE_DYN_CMD + SJA1105PQRS_SIZE_AVB_PARAMS_ENTRY)
+
 #define SJA1105_MAX_DYN_CMD_SIZE				\
 	SJA1105PQRS_SIZE_MAC_CONFIG_DYN_CMD
 
···
 	return 0;
 }
 
+static void
+sja1105pqrs_avb_params_cmd_packing(void *buf, struct sja1105_dyn_cmd *cmd,
+				   enum packing_op op)
+{
+	u8 *p = buf + SJA1105PQRS_SIZE_AVB_PARAMS_ENTRY;
+	const int size = SJA1105_SIZE_DYN_CMD;
+
+	sja1105_packing(p, &cmd->valid,   31, 31, size, op);
+	sja1105_packing(p, &cmd->errors,  30, 30, size, op);
+	sja1105_packing(p, &cmd->rdwrset, 29, 29, size, op);
+}
+
 #define OP_READ		BIT(0)
 #define OP_WRITE	BIT(1)
 #define OP_DEL		BIT(2)
···
 		.addr = 0x38,
 	},
 	[BLK_IDX_L2_FORWARDING_PARAMS] = {0},
-	[BLK_IDX_AVB_PARAMS] = {0},
+	[BLK_IDX_AVB_PARAMS] = {
+		.entry_packing = sja1105pqrs_avb_params_entry_packing,
+		.cmd_packing = sja1105pqrs_avb_params_cmd_packing,
+		.max_entry_count = SJA1105_MAX_AVB_PARAMS_COUNT,
+		.access = (OP_READ | OP_WRITE),
+		.packed_size = SJA1105PQRS_SIZE_AVB_PARAMS_DYN_CMD,
+		.addr = 0x8003,
+	},
 	[BLK_IDX_GENERAL_PARAMS] = {
 		.entry_packing = sja1105et_general_params_entry_packing,
 		.cmd_packing = sja1105et_general_params_cmd_packing,

drivers/net/dsa/sja1105/sja1105_main.c

···
 	return 0;
 }
 
+static int sja1105_init_avb_params(struct sja1105_private *priv)
+{
+	struct sja1105_avb_params_entry *avb;
+	struct sja1105_table *table;
+
+	table = &priv->static_config.tables[BLK_IDX_AVB_PARAMS];
+
+	/* Discard previous AVB Parameters Table */
+	if (table->entry_count) {
+		kfree(table->entries);
+		table->entry_count = 0;
+	}
+
+	table->entries = kcalloc(SJA1105_MAX_AVB_PARAMS_COUNT,
+				 table->ops->unpacked_entry_size, GFP_KERNEL);
+	if (!table->entries)
+		return -ENOMEM;
+
+	table->entry_count = SJA1105_MAX_AVB_PARAMS_COUNT;
+
+	avb = table->entries;
+
+	/* Configure the MAC addresses for meta frames */
+	avb->destmeta = SJA1105_META_DMAC;
+	avb->srcmeta  = SJA1105_META_SMAC;
+	/* On P/Q/R/S, configure the direction of the PTP_CLK pin as input by
+	 * default. This is because there might be boards with a hardware
+	 * layout where enabling the pin as output might cause an electrical
+	 * clash. On E/T the pin is always an output, which the board designers
+	 * probably already knew, so even if there are going to be electrical
+	 * issues, there's nothing we can do.
+	 */
+	avb->cas_master = false;
+
+	return 0;
+}
+
 #define SJA1105_RATE_MBPS(speed) (((speed) * 64000) / 1000)
 
 static void sja1105_setup_policer(struct sja1105_l2_policing_entry *policing,
···
 	if (rc < 0)
 		return rc;
 	rc = sja1105_init_general_params(priv);
+	if (rc < 0)
+		return rc;
+	rc = sja1105_init_avb_params(priv);
 	if (rc < 0)
 		return rc;
 

drivers/net/dsa/sja1105/sja1105_ptp.c

···
 #define SJA1105_MAX_ADJ_PPB		32000000
 #define SJA1105_SIZE_PTP_CMD		4
 
+/* PTPSYNCTS has no interrupt or update mechanism, because the intended
+ * hardware use case is for the timestamp to be collected synchronously,
+ * immediately after the CAS_MASTER SJA1105 switch has triggered a CASSYNC
+ * pulse on the PTP_CLK pin. When used as a generic extts source, it needs
+ * polling and a comparison with the old value. The polling interval is just
+ * the Nyquist rate of a canonical PPS input (e.g. from a GPS module).
+ * Anything of higher frequency than 1 Hz will be lost, since there is no
+ * timestamp FIFO.
+ */
+#define SJA1105_EXTTS_INTERVAL		(HZ / 2)
+
 /*            This range is actually +/- SJA1105_MAX_ADJ_PPB
  *            divided by 1000 (ppb -> ppm) and with a 16-bit
  *            "fractional" part (actually fixed point).
···
 	PTP_SET_MODE = 0,
 };
 
+#define extts_to_data(d) \
+		container_of((d), struct sja1105_ptp_data, extts_work)
 #define ptp_caps_to_data(d) \
 		container_of((d), struct sja1105_ptp_data, caps)
 #define ptp_data_to_sja1105(d) \
 		container_of((d), struct sja1105_private, ptp_data)
-
-static int sja1105_init_avb_params(struct sja1105_private *priv,
-				   bool on)
-{
-	struct sja1105_avb_params_entry *avb;
-	struct sja1105_table *table;
-
-	table = &priv->static_config.tables[BLK_IDX_AVB_PARAMS];
-
-	/* Discard previous AVB Parameters Table */
-	if (table->entry_count) {
-		kfree(table->entries);
-		table->entry_count = 0;
-	}
-
-	/* Configure the reception of meta frames only if requested */
-	if (!on)
-		return 0;
-
-	table->entries = kcalloc(SJA1105_MAX_AVB_PARAMS_COUNT,
-				 table->ops->unpacked_entry_size, GFP_KERNEL);
-	if (!table->entries)
-		return -ENOMEM;
-
-	table->entry_count = SJA1105_MAX_AVB_PARAMS_COUNT;
-
-	avb = table->entries;
-
-	avb->destmeta = SJA1105_META_DMAC;
-	avb->srcmeta  = SJA1105_META_SMAC;
-
-	return 0;
-}
 
 /* Must be called only with priv->tagger_data.state bit
  * SJA1105_HWTS_RX_EN cleared
···
 	struct sja1105_ptp_data *ptp_data = &priv->ptp_data;
 	struct sja1105_general_params_entry *general_params;
 	struct sja1105_table *table;
-	int rc;
 
 	table = &priv->static_config.tables[BLK_IDX_GENERAL_PARAMS];
 	general_params = table->entries;
 	general_params->send_meta1 = on;
 	general_params->send_meta0 = on;
-
-	rc = sja1105_init_avb_params(priv, on);
-	if (rc < 0)
-		return rc;
 
 	/* Initialize the meta state machine to a known state */
 	if (priv->tagger_data.stampable_skb) {
···
 	sja1105_packing(buf, &valid,           31, 31, size, op);
 	sja1105_packing(buf, &cmd->ptpstrtsch, 30, 30, size, op);
 	sja1105_packing(buf, &cmd->ptpstopsch, 29, 29, size, op);
+	sja1105_packing(buf, &cmd->startptpcp, 28, 28, size, op);
+	sja1105_packing(buf, &cmd->stopptpcp,  27, 27, size, op);
 	sja1105_packing(buf, &cmd->resptp,      2,  2, size, op);
 	sja1105_packing(buf, &cmd->corrclk4ts,  1,  1, size, op);
 	sja1105_packing(buf, &cmd->ptpclkadd,   0,  0, size, op);
···
 	sja1105_packing(buf, &valid,           31, 31, size, op);
 	sja1105_packing(buf, &cmd->ptpstrtsch, 30, 30, size, op);
 	sja1105_packing(buf, &cmd->ptpstopsch, 29, 29, size, op);
+	sja1105_packing(buf, &cmd->startptpcp, 28, 28, size, op);
+	sja1105_packing(buf, &cmd->stopptpcp,  27, 27, size, op);
 	sja1105_packing(buf, &cmd->resptp,      3,  3, size, op);
 	sja1105_packing(buf, &cmd->corrclk4ts,  2,  2, size, op);
 	sja1105_packing(buf, &cmd->ptpclkadd,   0,  0, size, op);
···
 	return rc;
 }
 
+static void sja1105_ptp_extts_work(struct work_struct *work)
+{
+	struct delayed_work *dw = to_delayed_work(work);
+	struct sja1105_ptp_data *ptp_data = extts_to_data(dw);
+	struct sja1105_private *priv = ptp_data_to_sja1105(ptp_data);
+	const struct sja1105_regs *regs = priv->info->regs;
+	struct ptp_clock_event event;
+	u64 ptpsyncts = 0;
+	int rc;
+
+	mutex_lock(&ptp_data->lock);
+
+	rc = sja1105_xfer_u64(priv, SPI_READ, regs->ptpsyncts, &ptpsyncts,
+			      NULL);
+	if (rc < 0)
+		dev_err_ratelimited(priv->ds->dev,
+				    "Failed to read PTPSYNCTS: %d\n", rc);
+
+	if (ptpsyncts && ptp_data->ptpsyncts != ptpsyncts) {
+		event.index = 0;
+		event.type = PTP_CLOCK_EXTTS;
+		event.timestamp = ns_to_ktime(sja1105_ticks_to_ns(ptpsyncts));
+		ptp_clock_event(ptp_data->clock, &event);
+
+		ptp_data->ptpsyncts = ptpsyncts;
+	}
+
+	mutex_unlock(&ptp_data->lock);
+
+	schedule_delayed_work(&ptp_data->extts_work, SJA1105_EXTTS_INTERVAL);
+}
+
+static int sja1105_change_ptp_clk_pin_func(struct sja1105_private *priv,
+					   enum ptp_pin_function func)
+{
+	struct sja1105_avb_params_entry *avb;
+	enum ptp_pin_function old_func;
+
+	avb = priv->static_config.tables[BLK_IDX_AVB_PARAMS].entries;
+
+	if (priv->info->device_id == SJA1105E_DEVICE_ID ||
+	    priv->info->device_id == SJA1105T_DEVICE_ID ||
+	    avb->cas_master)
+		old_func = PTP_PF_PEROUT;
+	else
+		old_func = PTP_PF_EXTTS;
+
+	if (func == old_func)
+		return 0;
+
+	avb->cas_master = (func == PTP_PF_PEROUT);
+
+	return sja1105_dynamic_config_write(priv, BLK_IDX_AVB_PARAMS, 0, avb,
+					    true);
+}
+
+/* The PTP_CLK pin may be configured to toggle with a 50% duty cycle and a
+ * frequency f:
+ *
+ *           NSEC_PER_SEC
+ * f = ----------------------
+ *     (PTPPINDUR * 8 ns) * 2
+ */
+static int sja1105_per_out_enable(struct sja1105_private *priv,
+				  struct ptp_perout_request *perout,
+				  bool on)
+{
+	struct sja1105_ptp_data *ptp_data = &priv->ptp_data;
+	const struct sja1105_regs *regs = priv->info->regs;
+	struct sja1105_ptp_cmd cmd = ptp_data->cmd;
+	int rc;
+
+	/* We only support one channel */
+	if (perout->index != 0)
+		return -EOPNOTSUPP;
+
+	/* Reject requests with unsupported flags */
+	if (perout->flags)
+		return -EOPNOTSUPP;
+
+	mutex_lock(&ptp_data->lock);
+
+	rc = sja1105_change_ptp_clk_pin_func(priv, PTP_PF_PEROUT);
+	if (rc)
+		goto out;
+
+	if (on) {
+		struct timespec64 pin_duration_ts = {
+			.tv_sec = perout->period.sec,
+			.tv_nsec = perout->period.nsec,
+		};
+		struct timespec64 pin_start_ts = {
+			.tv_sec = perout->start.sec,
+			.tv_nsec = perout->start.nsec,
+		};
+		u64 pin_duration = timespec64_to_ns(&pin_duration_ts);
+		u64 pin_start = timespec64_to_ns(&pin_start_ts);
+		u32 pin_duration32;
+		u64 now;
+
+		/* ptppindur: 32 bit register which holds the interval between
+		 * 2 edges on PTP_CLK. So check for truncation which happens
+		 * at periods larger than around 68.7 seconds.
+		 */
+		pin_duration = ns_to_sja1105_ticks(pin_duration / 2);
+		if (pin_duration > U32_MAX) {
+			rc = -ERANGE;
+			goto out;
+		}
+		pin_duration32 = pin_duration;
+
+		/* ptppins: 64 bit register which needs to hold a PTP time
+		 * larger than the current time, otherwise the startptpcp
+		 * command won't do anything. So advance the current time
+		 * by a number of periods in a way that won't alter the
+		 * phase offset.
+		 */
+		rc = __sja1105_ptp_gettimex(priv->ds, &now, NULL);
+		if (rc < 0)
+			goto out;
+
+		pin_start = future_base_time(pin_start, pin_duration,
+					     now + 1ull * NSEC_PER_SEC);
+		pin_start = ns_to_sja1105_ticks(pin_start);
+
+		rc = sja1105_xfer_u64(priv, SPI_WRITE, regs->ptppinst,
+				      &pin_start, NULL);
+		if (rc < 0)
+			goto out;
+
+		rc = sja1105_xfer_u32(priv, SPI_WRITE, regs->ptppindur,
+				      &pin_duration32, NULL);
+		if (rc < 0)
+			goto out;
+	}
+
+	if (on)
+		cmd.startptpcp = true;
+	else
+		cmd.stopptpcp = true;
+
+	rc = sja1105_ptp_commit(priv->ds, &cmd, SPI_WRITE);
+
+out:
+	mutex_unlock(&ptp_data->lock);
+
+	return rc;
+}
+
+static int sja1105_extts_enable(struct sja1105_private *priv,
+				struct ptp_extts_request *extts,
+				bool on)
+{
+	int rc;
+
+	/* We only support one channel */
+	if (extts->index != 0)
+		return -EOPNOTSUPP;
+
+	/* Reject requests with unsupported flags */
+	if (extts->flags)
+		return -EOPNOTSUPP;
+
+	rc = sja1105_change_ptp_clk_pin_func(priv, PTP_PF_EXTTS);
+	if (rc)
+		return rc;
+
+	if (on)
+		schedule_delayed_work(&priv->ptp_data.extts_work,
+				      SJA1105_EXTTS_INTERVAL);
+	else
+		cancel_delayed_work_sync(&priv->ptp_data.extts_work);
+
+	return 0;
+}
+
+static int sja1105_ptp_enable(struct ptp_clock_info *ptp,
+			      struct ptp_clock_request *req, int on)
+{
+	struct sja1105_ptp_data *ptp_data = ptp_caps_to_data(ptp);
+	struct sja1105_private *priv = ptp_data_to_sja1105(ptp_data);
+	int rc = -EOPNOTSUPP;
+
+	if (req->type == PTP_CLK_REQ_PEROUT)
+		rc = sja1105_per_out_enable(priv, &req->perout, on);
+	else if (req->type == PTP_CLK_REQ_EXTTS)
+		rc = sja1105_extts_enable(priv, &req->extts, on);
+
+	return rc;
+}
+
+static int sja1105_ptp_verify_pin(struct ptp_clock_info *ptp, unsigned int pin,
+				  enum ptp_pin_function func, unsigned int chan)
+{
+	struct sja1105_ptp_data *ptp_data = ptp_caps_to_data(ptp);
+	struct sja1105_private *priv = ptp_data_to_sja1105(ptp_data);
+
+	if (chan != 0 || pin != 0)
+		return -1;
+
+	switch (func) {
+	case PTP_PF_NONE:
+	case PTP_PF_PEROUT:
+		break;
+	case PTP_PF_EXTTS:
+		if (priv->info->device_id == SJA1105E_DEVICE_ID ||
+		    priv->info->device_id == SJA1105T_DEVICE_ID)
+			return -1;
+		break;
+	default:
+		return -1;
+	}
+	return 0;
+}
+
+static struct ptp_pin_desc sja1105_ptp_pin = {
+	.name = "ptp_clk",
+	.index = 0,
+	.func = PTP_PF_NONE,
+};
+
 int sja1105_ptp_clock_register(struct dsa_switch *ds)
 {
 	struct sja1105_private *priv = ds->priv;
···
 		.adjtime	= sja1105_ptp_adjtime,
 		.gettimex64	= sja1105_ptp_gettimex,
 		.settime64	= sja1105_ptp_settime,
+		.enable		= sja1105_ptp_enable,
+		.verify		= sja1105_ptp_verify_pin,
 		.do_aux_work	= sja1105_rxtstamp_work,
 		.max_adj	= SJA1105_MAX_ADJ_PPB,
+		.pin_config	= &sja1105_ptp_pin,
+		.n_pins		= 1,
+		.n_ext_ts	= 1,
+		.n_per_out	= 1,
 	};
 
 	skb_queue_head_init(&ptp_data->skb_rxtstamp_queue);
···
 	ptp_data->cmd.corrclk4ts = true;
 	ptp_data->cmd.ptpclkadd = PTP_SET_MODE;
 
+	INIT_DELAYED_WORK(&ptp_data->extts_work, sja1105_ptp_extts_work);
+
 	return sja1105_ptp_reset(ds);
 }
 
···
 	if (IS_ERR_OR_NULL(ptp_data->clock))
 		return;
 
+	cancel_delayed_work_sync(&ptp_data->extts_work);
 	ptp_cancel_worker_sync(ptp_data->clock);
 	skb_queue_purge(&ptp_data->skb_rxtstamp_queue);
 	ptp_clock_unregister(ptp_data->clock);

drivers/net/dsa/sja1105/sja1105_ptp.h

···
 	return ticks * SJA1105_TICK_NS;
 }
 
+/* Calculate the first base_time in the future that satisfies this
+ * relationship:
+ *
+ * future_base_time = base_time + N x cycle_time >= now, or
+ *
+ *      now - base_time
+ * N >= ---------------
+ *         cycle_time
+ *
+ * Because N is an integer, the ceiling value of the above "a / b" ratio
+ * is in fact precisely the floor value of "(a + b - 1) / b", which is
+ * easier to calculate only having integer division tools.
+ */
+static inline s64 future_base_time(s64 base_time, s64 cycle_time, s64 now)
+{
+	s64 a, b, n;
+
+	if (base_time >= now)
+		return base_time;
+
+	a = now - base_time;
+	b = cycle_time;
+	n = div_s64(a + b - 1, b);
+
+	return base_time + n * cycle_time;
+}
+
 struct sja1105_ptp_cmd {
+	u64 startptpcp;		/* start toggling PTP_CLK pin */
+	u64 stopptpcp;		/* stop toggling PTP_CLK pin */
 	u64 ptpstrtsch;		/* start schedule */
 	u64 ptpstopsch;		/* stop schedule */
 	u64 resptp;		/* reset */
···
 };
 
 struct sja1105_ptp_data {
+	struct delayed_work extts_work;
 	struct sk_buff_head skb_rxtstamp_queue;
 	struct ptp_clock_info caps;
 	struct ptp_clock *clock;
 	struct sja1105_ptp_cmd cmd;
 	/* Serializes all operations on the PTP hardware clock */
 	struct mutex lock;
+	u64 ptpsyncts;
 };
 
 int sja1105_ptp_clock_register(struct dsa_switch *ds);

drivers/net/dsa/sja1105/sja1105_spi.c

···
 	.rmii_ext_tx_clk = {0x100018, 0x10001F, 0x100026, 0x10002D, 0x100034},
 	.ptpegr_ts = {0xC0, 0xC2, 0xC4, 0xC6, 0xC8},
 	.ptpschtm = 0x12, /* Spans 0x12 to 0x13 */
+	.ptppinst = 0x14,
+	.ptppindur = 0x16,
 	.ptp_control = 0x17,
 	.ptpclkval = 0x18, /* Spans 0x18 to 0x19 */
 	.ptpclkrate = 0x1A,
···
 	.qlevel = {0x604, 0x614, 0x624, 0x634, 0x644},
 	.ptpegr_ts = {0xC0, 0xC4, 0xC8, 0xCC, 0xD0},
 	.ptpschtm = 0x13, /* Spans 0x13 to 0x14 */
+	.ptppinst = 0x15,
+	.ptppindur = 0x17,
 	.ptp_control = 0x18,
 	.ptpclkval = 0x19,
 	.ptpclkrate = 0x1B,
 	.ptpclkcorp = 0x1E,
+	.ptpsyncts = 0x1F,
 };
 
 struct sja1105_info sja1105e_info = {

drivers/net/dsa/sja1105/sja1105_static_config.c

···
 	return size;
 }
 
-static size_t sja1105pqrs_avb_params_entry_packing(void *buf, void *entry_ptr,
-						   enum packing_op op)
+size_t sja1105pqrs_avb_params_entry_packing(void *buf, void *entry_ptr,
+					    enum packing_op op)
 {
 	const size_t size = SJA1105PQRS_SIZE_AVB_PARAMS_ENTRY;
 	struct sja1105_avb_params_entry *entry = entry_ptr;
 
+	sja1105_packing(buf, &entry->cas_master, 126, 126, size, op);
 	sja1105_packing(buf, &entry->destmeta,   125,  78, size, op);
 	sja1105_packing(buf, &entry->srcmeta,     77,  30, size, op);
 	return size;

drivers/net/dsa/sja1105/sja1105_static_config.h

···
 };
 
 struct sja1105_avb_params_entry {
+	u64 cas_master;
 	u64 destmeta;
 	u64 srcmeta;
 };

drivers/net/dsa/sja1105/sja1105_tas.c

···
 	return delta * 200;
 }
 
-/* Calculate the first base_time in the future that satisfies this
- * relationship:
- *
- * future_base_time = base_time + N x cycle_time >= now, or
- *
- *      now - base_time
- * N >= ---------------
- *         cycle_time
- *
- * Because N is an integer, the ceiling value of the above "a / b" ratio
- * is in fact precisely the floor value of "(a + b - 1) / b", which is
- * easier to calculate only having integer division tools.
- */
-static s64 future_base_time(s64 base_time, s64 cycle_time, s64 now)
-{
-	s64 a, b, n;
-
-	if (base_time >= now)
-		return base_time;
-
-	a = now - base_time;
-	b = cycle_time;
-	n = div_s64(a + b - 1, b);
-
-	return base_time + n * cycle_time;
-}
-
 static int sja1105_tas_set_runtime_params(struct sja1105_private *priv)
 {
 	struct sja1105_tas_data *tas_data = &priv->tas_data;