clocksource/drivers/sp804: Enable Hisilicon sp804 timer 64bit mode

A 100MHZ 32-bit timer will be wrapped up less than 43s. Although the
kernel maintains a software high 32-bit count in the tick IRQ. But it's
not applicable to the user mode APPs.

Note: The kernel still uses the lower 32 bits of the timer.
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200918132237.3552-9-thunder.leizhen@huawei.com

drivers/clocksource/timer-sp.h

@@ -33,12 +33,15 @@
 
 struct sp804_timer {
 	int load;
+	int load_h;
 	int value;
+	int value_h;
 	int ctrl;
 	int intclr;
 	int ris;
 	int mis;
 	int bgload;
+	int bgload_h;
 	int timer_base[NR_TIMERS];
 	int width;
 };
@@ -46,12 +49,15 @@ struct sp804_timer {
 struct sp804_clkevt {
 	void __iomem *base;
 	void __iomem *load;
+	void __iomem *load_h;
 	void __iomem *value;
+	void __iomem *value_h;
 	void __iomem *ctrl;
 	void __iomem *intclr;
 	void __iomem *ris;
 	void __iomem *mis;
 	void __iomem *bgload;
+	void __iomem *bgload_h;
 	unsigned long reload;
 	int width;
 };

drivers/clocksource/timer-sp804.c

@@ -24,12 +24,15 @@
 #define HISI_TIMER_1_BASE	0x00
 #define HISI_TIMER_2_BASE	0x40
 #define HISI_TIMER_LOAD		0x00
+#define HISI_TIMER_LOAD_H	0x04
 #define HISI_TIMER_VALUE	0x08
+#define HISI_TIMER_VALUE_H	0x0c
 #define HISI_TIMER_CTRL		0x10
 #define HISI_TIMER_INTCLR	0x14
 #define HISI_TIMER_RIS		0x18
 #define HISI_TIMER_MIS		0x1c
 #define HISI_TIMER_BGLOAD	0x20
+#define HISI_TIMER_BGLOAD_H	0x24
 
 
 struct sp804_timer __initdata arm_sp804_timer = {
@@ -43,7 +46,9 @@ struct sp804_timer __initdata arm_sp804_timer = {
 
 struct sp804_timer __initdata hisi_sp804_timer = {
 	.load		= HISI_TIMER_LOAD,
+	.load_h		= HISI_TIMER_LOAD_H,
 	.value		= HISI_TIMER_VALUE,
+	.value_h	= HISI_TIMER_VALUE_H,
 	.ctrl		= HISI_TIMER_CTRL,
 	.intclr		= HISI_TIMER_INTCLR,
 	.timer_base	= {HISI_TIMER_1_BASE, HISI_TIMER_2_BASE},
@@ -129,6 +134,10 @@ int __init sp804_clocksource_and_sched_clock_init(void __iomem *base,
 	writel(0, clkevt->ctrl);
 	writel(0xffffffff, clkevt->load);
 	writel(0xffffffff, clkevt->value);
+	if (clkevt->width == 64) {
+		writel(0xffffffff, clkevt->load_h);
+		writel(0xffffffff, clkevt->value_h);
+	}
 	writel(TIMER_CTRL_32BIT | TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC,
 		clkevt->ctrl);
 
@@ -245,7 +254,9 @@ static void __init sp804_clkevt_init(struct sp804_timer *timer, void __iomem *ba
 		clkevt = &sp804_clkevt[i];
 		clkevt->base	= timer_base;
 		clkevt->load	= timer_base + timer->load;
+		clkevt->load_h	= timer_base + timer->load_h;
 		clkevt->value	= timer_base + timer->value;
+		clkevt->value_h	= timer_base + timer->value_h;
 		clkevt->ctrl	= timer_base + timer->ctrl;
 		clkevt->intclr	= timer_base + timer->intclr;
 		clkevt->width	= timer->width;