net: ethernet: ti: cpts: add irq support

Add CPTS IRQ support, but do not enable it. By default, the CPTS driver
will continue working using polling mode which is required for CPTS to
continue working on platforms other than CPSW, like Keystone 2.

The CPTS IRQ support is required to enable support for HW_TS_PUSH events.
The CPSW CPTS IRQ and HW_TS_PUSH events support will be enabled in follow
up patches.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/ti/cpts.c

@@ -99,6 +99,7 @@ static void cpts_purge_txq(struct cpts *cpts)
  */
 static int cpts_fifo_read(struct cpts *cpts, int match)
 {
+	bool need_schedule = false;
 	struct cpts_event *event;
 	unsigned long flags;
 	int i, type = -1;
@@ -131,6 +132,8 @@ static int cpts_fifo_read(struct cpts *cpts, int match)
 				cpts->cc.mult = cpts->mult_new;
 				cpts->mult_new = 0;
 			}
+			if (!cpts->irq_poll)
+				complete(&cpts->ts_push_complete);
 			break;
 		case CPTS_EV_TX:
 		case CPTS_EV_RX:
@@ -139,6 +142,7 @@ static int cpts_fifo_read(struct cpts *cpts, int match)
 
 			list_del_init(&event->list);
 			list_add_tail(&event->list, &cpts->events);
+			need_schedule = true;
 			break;
 		case CPTS_EV_ROLL:
 		case CPTS_EV_HALF:
@@ -154,9 +158,18 @@ static int cpts_fifo_read(struct cpts *cpts, int match)
 
 	spin_unlock_irqrestore(&cpts->lock, flags);
 
+	if (!cpts->irq_poll && need_schedule)
+		ptp_schedule_worker(cpts->clock, 0);
+
 	return type == match ? 0 : -1;
 }
 
+void cpts_misc_interrupt(struct cpts *cpts)
+{
+	cpts_fifo_read(cpts, -1);
+}
+EXPORT_SYMBOL_GPL(cpts_misc_interrupt);
+
 static u64 cpts_systim_read(const struct cyclecounter *cc)
 {
 	struct cpts *cpts = container_of(cc, struct cpts, cc);
@@ -169,6 +182,8 @@ static void cpts_update_cur_time(struct cpts *cpts, int match,
 {
 	unsigned long flags;
 
+	reinit_completion(&cpts->ts_push_complete);
+
 	/* use spin_lock_irqsave() here as it has to run very fast */
 	spin_lock_irqsave(&cpts->lock, flags);
 	ptp_read_system_prets(sts);
@@ -177,8 +192,12 @@ static void cpts_update_cur_time(struct cpts *cpts, int match,
 	ptp_read_system_postts(sts);
 	spin_unlock_irqrestore(&cpts->lock, flags);
 
-	if (cpts_fifo_read(cpts, match) && match != -1)
+	if (cpts->irq_poll && cpts_fifo_read(cpts, match) && match != -1)
 		dev_err(cpts->dev, "cpts: unable to obtain a time stamp\n");
+
+	if (!cpts->irq_poll &&
+	    !wait_for_completion_timeout(&cpts->ts_push_complete, HZ))
+		dev_err(cpts->dev, "cpts: obtain a time stamp timeout\n");
 }
 
 /* PTP clock operations */
@@ -708,8 +727,10 @@ struct cpts *cpts_create(struct device *dev, void __iomem *regs,
 
 	cpts->dev = dev;
 	cpts->reg = (struct cpsw_cpts __iomem *)regs;
+	cpts->irq_poll = true;
 	spin_lock_init(&cpts->lock);
 	mutex_init(&cpts->ptp_clk_mutex);
+	init_completion(&cpts->ts_push_complete);
 
 	ret = cpts_of_parse(cpts, node);
 	if (ret)

drivers/net/ethernet/ti/cpts.h

@@ -118,6 +118,8 @@ struct cpts {
 	u64 cur_timestamp;
 	u32 mult_new;
 	struct mutex ptp_clk_mutex; /* sync PTP interface and worker */
+	bool irq_poll;
+	struct completion	ts_push_complete;
 };
 
 void cpts_rx_timestamp(struct cpts *cpts, struct sk_buff *skb);
@@ -127,6 +129,7 @@ void cpts_unregister(struct cpts *cpts);
 struct cpts *cpts_create(struct device *dev, void __iomem *regs,
 			 struct device_node *node);
 void cpts_release(struct cpts *cpts);
+void cpts_misc_interrupt(struct cpts *cpts);
 
 static inline bool cpts_can_timestamp(struct cpts *cpts, struct sk_buff *skb)
 {
@@ -138,6 +141,11 @@ static inline bool cpts_can_timestamp(struct cpts *cpts, struct sk_buff *skb)
 	return true;
 }
 
+static inline void cpts_set_irqpoll(struct cpts *cpts, bool en)
+{
+	cpts->irq_poll = en;
+}
+
 #else
 struct cpts;
 
@@ -173,6 +181,14 @@ static inline bool cpts_can_timestamp(struct cpts *cpts, struct sk_buff *skb)
 {
 	return false;
 }
+
+static inline void cpts_misc_interrupt(struct cpts *cpts)
+{
+}
+
+static inline void cpts_set_irqpoll(struct cpts *cpts, bool en)
+{
+}
 #endif