ssb: set the PMU watchdog if available

Some ssb based devices have a PMU and the PMU watchdog register should
be used instead of the register in the chip common part, if the device
has a PMU. This patch also calculates the maximal number the watchdog
could be set to.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/ssb/driver_chipcommon.c

@@ -288,6 +288,24 @@ static u32 ssb_chipco_alp_clock(struct ssb_chipcommon *cc)
 	return 20000000;
 }
 
+static u32 ssb_chipco_watchdog_get_max_timer(struct ssb_chipcommon *cc)
+{
+	u32 nb;
+
+	if (cc->capabilities & SSB_CHIPCO_CAP_PMU) {
+		if (cc->dev->id.revision < 26)
+			nb = 16;
+		else
+			nb = (cc->dev->id.revision >= 37) ? 32 : 24;
+	} else {
+		nb = 28;
+	}
+	if (nb == 32)
+		return 0xffffffff;
+	else
+		return (1 << nb) - 1;
+}
+
 void ssb_chipcommon_init(struct ssb_chipcommon *cc)
 {
 	if (!cc->dev)
@@ -405,8 +423,24 @@ void ssb_chipco_timing_init(struct ssb_chipcommon *cc,
 /* Set chip watchdog reset timer to fire in 'ticks' backplane cycles */
 void ssb_chipco_watchdog_timer_set(struct ssb_chipcommon *cc, u32 ticks)
 {
+	u32 maxt;
+	enum ssb_clkmode clkmode;
+
+	maxt = ssb_chipco_watchdog_get_max_timer(cc);
+	if (cc->capabilities & SSB_CHIPCO_CAP_PMU) {
+		if (ticks == 1)
+			ticks = 2;
+		else if (ticks > maxt)
+			ticks = maxt;
+		chipco_write32(cc, SSB_CHIPCO_PMU_WATCHDOG, ticks);
+	} else {
+		clkmode = ticks ? SSB_CLKMODE_FAST : SSB_CLKMODE_DYNAMIC;
+		ssb_chipco_set_clockmode(cc, clkmode);
+		if (ticks > maxt)
+			ticks = maxt;
 		/* instant NMI */
 		chipco_write32(cc, SSB_CHIPCO_WATCHDOG, ticks);
+	}
 }
 
 void ssb_chipco_irq_mask(struct ssb_chipcommon *cc, u32 mask, u32 value)