Add support for watchdog on Armada38x

A38X watchdog support was implemented in sys/arm/mv/timer.c driver.
It required following modifications:
- add "marvell,armada-380-wdt" compatibility, which supports only watchdog
- correct and enhance definitions related to timer control register
- unmask reset capability in RSTOUTn_MASK register
- use dedicated watchdog timer on A38X instead of second timer

Obtained from:  Semihalf
Sponsored by:   Stormshield
Submitted by:   Bartosz Szczepanek <bsz@semihalf.com>
Differential revision:  https://reviews.freebsd.org/D4423

2 files changed, 54 insertions, 9 deletions

diff --git a/sys/arm/mv/mvreg.h b/sys/arm/mv/mvreg.h
index 324c5ea..fa807a0 100644
--- a/sys/arm/mv/mvreg.h
+++ b/sys/arm/mv/mvreg.h
@@ -127,6 +127,7 @@
  */
 #if defined(SOC_MV_ARMADAXP) || defined(SOC_MV_ARMADA38X)
 #define RSTOUTn_MASK		0x60
+#define	RSTOUTn_MASK_WD		0x400
 #define SYSTEM_SOFT_RESET	0x64
 #define WD_RSTOUTn_MASK		0x4
 #define WD_GLOBAL_MASK		0x00000100
@@ -219,8 +220,10 @@
 #define CPU_TIMER0_AUTO		0x00000002
 #define CPU_TIMER1_EN		0x00000004
 #define CPU_TIMER1_AUTO		0x00000008
-#define CPU_TIMER_WD_EN		0x00000010
-#define CPU_TIMER_WD_AUTO	0x00000020
+#define	CPU_TIMER2_EN		0x00000010
+#define	CPU_TIMER2_AUTO		0x00000020
+#define	CPU_TIMER_WD_EN		0x00000100
+#define	CPU_TIMER_WD_AUTO	0x00000200
 /* 25MHz mode is Armada XP - specific */
 #define CPU_TIMER_WD_25MHZ_EN	0x00000400
 #define CPU_TIMER0_25MHZ_EN	0x00000800
diff --git a/sys/arm/mv/timer.c b/sys/arm/mv/timer.c
index a4e714c..a363ed4 100644
--- a/sys/arm/mv/timer.c
+++ b/sys/arm/mv/timer.c
@@ -54,12 +54,22 @@ __FBSDID("$FreeBSD$");
 #define INITIAL_TIMECOUNTER	(0xffffffff)
 #define MAX_WATCHDOG_TICKS	(0xffffffff)
 
+#define	MV_TMR	0x1
+#define	MV_WDT	0x2
+#define	MV_NONE	0x0
+
 #if defined(SOC_MV_ARMADAXP) || defined(SOC_MV_ARMADA38X)
 #define MV_CLOCK_SRC		25000000	/* Timers' 25MHz mode */
 #else
 #define MV_CLOCK_SRC		get_tclk()
 #endif
 
+#if defined(SOC_MV_ARMADA38X)
+#define	WATCHDOG_TIMER	4
+#else
+#define	WATCHDOG_TIMER	2
+#endif
+
 struct mv_timer_softc {
 	struct resource	*	timer_res[2];
 	bus_space_tag_t		timer_bst;
@@ -70,10 +80,17 @@ struct mv_timer_softc {
 
 static struct resource_spec mv_timer_spec[] = {
 	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
-	{ SYS_RES_IRQ,		0,	RF_ACTIVE },
+	{ SYS_RES_IRQ,		0,	RF_ACTIVE | RF_OPTIONAL },
 	{ -1, 0 }
 };
 
+/* Interrupt is not required by MV_WDT devices */
+static struct ofw_compat_data mv_timer_compat[] = {
+	{"mrvl,timer",			MV_TMR | MV_WDT },
+	{"marvell,armada-380-wdt",	MV_WDT },
+	{NULL,				MV_NONE }
+};
+
 static struct mv_timer_softc *timer_softc = NULL;
 static int timers_initialized = 0;
 
@@ -111,7 +128,7 @@ mv_timer_probe(device_t dev)
 	if (!ofw_bus_status_okay(dev))
 		return (ENXIO);
 
-	if (!ofw_bus_is_compatible(dev, "mrvl,timer"))
+	if (ofw_bus_search_compatible(dev, mv_timer_compat)->ocd_data == MV_NONE)
 		return (ENXIO);
 
 	device_set_desc(dev, "Marvell CPU Timer");
@@ -147,6 +164,17 @@ mv_timer_attach(device_t dev)
 	mv_watchdog_disable();
 	EVENTHANDLER_REGISTER(watchdog_list, mv_watchdog_event, sc, 0);
 
+	if (ofw_bus_search_compatible(dev, mv_timer_compat)->ocd_data
+	    == MV_WDT) {
+		/* Don't set timers for wdt-only entry. */
+		device_printf(dev, "only watchdog attached\n");
+		return (0);
+	} else if (sc->timer_res[1] == NULL) {
+		device_printf(dev, "no interrupt resource\n");
+		bus_release_resources(dev, mv_timer_spec, sc->timer_res);
+		return (ENXIO);
+	}
+
 	if (bus_setup_intr(dev, sc->timer_res[1], INTR_TYPE_CLK,
 	    mv_hardclock, NULL, sc, &ihl) != 0) {
 		bus_release_resources(dev, mv_timer_spec, sc->timer_res);
@@ -306,6 +334,10 @@ mv_watchdog_enable(void)
 	val = read_cpu_mp_clocks(WD_RSTOUTn_MASK);
 	val |= (WD_GLOBAL_MASK | WD_CPU0_MASK);
 	write_cpu_mp_clocks(WD_RSTOUTn_MASK, val);
+
+	val = read_cpu_misc(RSTOUTn_MASK);
+	val &= ~RSTOUTn_MASK_WD;
+	write_cpu_misc(RSTOUTn_MASK, val);
 #else
 	irq_mask = read_cpu_ctrl(BRIDGE_IRQ_MASK);
 	irq_mask |= IRQ_TIMER_WD_MASK;
@@ -317,9 +349,12 @@ mv_watchdog_enable(void)
 #endif
 
 	val = mv_get_timer_control();
-	val |= CPU_TIMER_WD_EN | CPU_TIMER_WD_AUTO;
-#if defined(SOC_MV_ARMADAXP) || defined(SOC_MV_ARMADA38X)
-	val |= CPU_TIMER_WD_25MHZ_EN;
+#if defined(SOC_MV_ARMADA38X)
+	val |= CPU_TIMER_WD_EN | CPU_TIMER_WD_AUTO | CPU_TIMER_WD_25MHZ_EN;
+#elif defined(SOC_MV_ARMADAXP)
+	val |= CPU_TIMER2_EN | CPU_TIMER2_AUTO | CPU_TIMER_WD_25MHZ_EN;
+#else
+	val |= CPU_TIMER2_EN | CPU_TIMER2_AUTO;
 #endif
 	mv_set_timer_control(val);
 }
@@ -333,13 +368,21 @@ mv_watchdog_disable(void)
 #endif
 
 	val = mv_get_timer_control();
+#if defined(SOC_MV_ARMADA38X)
 	val &= ~(CPU_TIMER_WD_EN | CPU_TIMER_WD_AUTO);
+#else
+	val &= ~(CPU_TIMER2_EN | CPU_TIMER2_AUTO);
+#endif
 	mv_set_timer_control(val);
 
 #if defined(SOC_MV_ARMADAXP) || defined(SOC_MV_ARMADA38X)
 	val = read_cpu_mp_clocks(WD_RSTOUTn_MASK);
 	val &= ~(WD_GLOBAL_MASK | WD_CPU0_MASK);
 	write_cpu_mp_clocks(WD_RSTOUTn_MASK, val);
+
+	val = read_cpu_misc(RSTOUTn_MASK);
+	val |= RSTOUTn_MASK_WD;
+	write_cpu_misc(RSTOUTn_MASK, RSTOUTn_MASK_WD);
 #else
 	val = read_cpu_ctrl(RSTOUTn_MASK);
 	val &= ~WD_RST_OUT_EN;
@@ -378,8 +421,7 @@ mv_watchdog_event(void *arg, unsigned int cmd, int *error)
 		if (ticks > MAX_WATCHDOG_TICKS)
 			mv_watchdog_disable();
 		else {
-			/* Timer 2 is the watchdog */
-			mv_set_timer(2, ticks);
+			mv_set_timer(WATCHDOG_TIMER, ticks);
 			mv_watchdog_enable();
 			*error = 0;
 		}