GPTC heartbeat timer for ledc

drivers/clocksource/intel-gptc-timer.c

@@ -83,6 +83,7 @@ enum gptc_timer_type {
 	TIMER_TYPE_CLK_SRC,
 	TIMER_TYPE_CLK_EVT,
 	TIMER_TYPE_WDT,
+	TIMER_TYPE_HEARTBEAT,
 	TIMER_TYPE_MAX,
 };
 
@@ -117,6 +118,7 @@ struct gptc_timer {
 	struct list_head clksrc; /* Node in clock source list */
 	struct list_head clkevt; /* Node in clock event list */
 	struct list_head wdt; /* Node in watchdog timer */
+	struct list_head heartbeat; /* Heartbeat */
 };
 
 struct gptc_clocksource {
@@ -135,6 +137,7 @@ static LIST_HEAD(gptc_list);
 static LIST_HEAD(gptc_clksrc_list);
 static LIST_HEAD(gptc_clkevt_list);
 static LIST_HEAD(gptc_wdt_list);
+static LIST_HEAD(gptc_heartbeat_list);
 
 unsigned long gptc_phy_base;
 static bool gptc_clksrc_init;
@@ -355,7 +358,8 @@ static void gptc_per_timer_init(struct gptc_timer *timer)
 	gptc_count_dir(timer);
 	gptc_enable_32bit_timer(timer);
 	gptc_reset_counter(timer);
-	if (timer->type == TIMER_TYPE_CLK_SRC)
+	if (timer->type == TIMER_TYPE_CLK_SRC ||
+	    timer->type == TIMER_TYPE_HEARTBEAT)
 		gptc_reload_and_run(timer);
 }
 
@@ -370,6 +374,8 @@ static const char *const timer_type_to_str(u32 type)
 
 	case TIMER_TYPE_WDT:
 		return "wdt";
+	case TIMER_TYPE_HEARTBEAT:
+		return "heartbeat";
 	default:
 		return "none";
 	}
@@ -545,6 +551,13 @@ static int gptc_of_parse_timer(struct gptc *gptc)
 			timer->cpuid = 0;
 			list_add_tail(&timer->clksrc, &gptc_clksrc_list);
 			break;
+		case TIMER_TYPE_HEARTBEAT:
+			INIT_LIST_HEAD(&timer->heartbeat);
+			timer->irq = 0;
+			timer->dir = GPTC_COUNT_UP;
+			timer->cpuid = 0;
+			list_add_tail(&timer->heartbeat, &gptc_heartbeat_list);
+			break;
 		case TIMER_TYPE_CLK_EVT:
 		case TIMER_TYPE_WDT:
 			timer->irq = irq_of_parse_and_map(np, timer->tid);
@@ -850,6 +863,24 @@ static int __init gptc_timer_init(struct device_node *np)
 CLOCKSOURCE_OF_DECLARE(lantiq_gptc_timer, "lantiq,gptc", gptc_timer_init);
 CLOCKSOURCE_OF_DECLARE(intel_gptc_timer, "intel,gptc", gptc_timer_init);
 
+static int __init gptc_heartbeat_init(void)
+{
+	struct gptc_timer *timer;
+
+	list_for_each_entry(timer, &gptc_heartbeat_list, heartbeat) {
+		if (!timer->used) {
+			gptc_per_timer_init(timer);
+			timer->used = true;
+			gptc_get(timer->gptc);
+			pr_debug("gptc %d timer %d heartbeat register @cpu%d\n",
+				 timer->gptcid, timer->tid, timer->cpuid);
+			return 0;
+		}
+	}
+	return -EINVAL;
+}
+arch_initcall(gptc_heartbeat_init);
+
 static void *gptc_seq_start(struct seq_file *s, loff_t *pos)
 {
 	if (list_empty(&gptc_list))