clockevents: ARM sp804: obtain sp804 timer rate via clks

This allows platforms to specify the rate of the SP804 clockevent via
the clk subsystem. While ARM boards clock these at 1MHz, BCMRing also
has SP804 timers but are clocked at different rates.

Acked-by: Catalin Marinas <[e-mail]>
Signed-off-by: Russell King <[e-mail]>

arch/arm/common/timer-sp.c

···
 
 #include <asm/hardware/arm_timer.h>
 
-/*
- * These timers are currently always setup to be clocked at 1MHz.
- */
-#define TIMER_FREQ_KHZ	(1000)
-#define TIMER_RELOAD	(TIMER_FREQ_KHZ * 1000 / HZ)
-
 static long __init sp804_get_clock_rate(const char *name)
 {
 	struct clk *clk;
···
 
 
 static void __iomem *clkevt_base;
+static unsigned long clkevt_reload;
 
 /*
  * IRQ handler for the timer
···
 
 	switch (mode) {
 	case CLOCK_EVT_MODE_PERIODIC:
-		writel(TIMER_RELOAD, clkevt_base + TIMER_LOAD);
+		writel(clkevt_reload, clkevt_base + TIMER_LOAD);
 		ctrl |= TIMER_CTRL_PERIODIC | TIMER_CTRL_ENABLE;
 		break;
 
···
 	const char *name)
 {
 	struct clock_event_device *evt = &sp804_clockevent;
+	long rate = sp804_get_clock_rate(name);
+
+	if (rate < 0)
+		return;
 
 	clkevt_base = base;
+	clkevt_reload = DIV_ROUND_CLOSEST(rate, HZ);
 
 	evt->name = name;
 	evt->irq = irq;
-	evt->mult = div_sc(TIMER_FREQ_KHZ, NSEC_PER_MSEC, evt->shift);
+	evt->mult = div_sc(rate, NSEC_PER_SEC, evt->shift);
 	evt->max_delta_ns = clockevent_delta2ns(0xffffffff, evt);
 	evt->min_delta_ns = clockevent_delta2ns(0xf, evt);
 

arch/arm/mach-vexpress/ct-ca9x4.c

···
 		.clk		= &osc1_clk,
 	}, {	/* SP804 timers */
 		.dev_id		= "sp804",
+		.con_id		= "ct-timer0",
+		.clk		= &ct_sp804_clk,
+	}, {	/* SP804 timers */
+		.dev_id		= "sp804",
 		.con_id		= "ct-timer1",
 		.clk		= &ct_sp804_clk,
 	},

arch/arm/mach-vexpress/v2m.c

···
 		.clk		= &osc1_clk,
 	}, {	/* SP804 timers */
 		.dev_id		= "sp804",
+		.con_id		= "v2m-timer0",
+		.clk		= &v2m_sp804_clk,
+	}, {	/* SP804 timers */
+		.dev_id		= "sp804",
 		.con_id		= "v2m-timer1",
 		.clk		= &v2m_sp804_clk,
 	},