ARM: mmp/mmp2: dt: enable the clock

The device-tree booted MMP2 needs to enable the timer clock, otherwise
it would stop ticking when the boot finishes.

It can also use the clock rate from the clk, the non-DT boards need to
keep using the hardcoded rates.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Olof Johansson <olof@lixom.net>

arch/arm/mach-mmp/common.h

@@ -2,7 +2,7 @@
 #include <linux/reboot.h>
 #define ARRAY_AND_SIZE(x)	(x), ARRAY_SIZE(x)
 
-extern void timer_init(int irq);
+extern void timer_init(int irq, unsigned long rate);
 
 extern void __init mmp_map_io(void);
 extern void mmp_restart(enum reboot_mode, const char *);

arch/arm/mach-mmp/mmp2.c

@@ -134,7 +134,7 @@ void __init mmp2_timer_init(void)
 	clk_rst = APBC_APBCLK | APBC_FNCLK | APBC_FNCLKSEL(1);
 	__raw_writel(clk_rst, APBC_TIMERS);
 
-	timer_init(IRQ_MMP2_TIMER1);
+	timer_init(IRQ_MMP2_TIMER1, 6500000);
 }
 
 /* on-chip devices */

arch/arm/mach-mmp/pxa168.c

@@ -79,7 +79,7 @@ void __init pxa168_timer_init(void)
 	/* 3.25MHz, bus/functional clock enabled, release reset */
 	__raw_writel(TIMER_CLK_RST, APBC_TIMERS);
 
-	timer_init(IRQ_PXA168_TIMER1);
+	timer_init(IRQ_PXA168_TIMER1, 6500000);
 }
 
 void pxa168_clear_keypad_wakeup(void)

arch/arm/mach-mmp/time.c

@@ -22,6 +22,7 @@
 #include <linux/kernel.h>
 #include <linux/interrupt.h>
 #include <linux/clockchips.h>
+#include <linux/clk.h>
 
 #include <linux/io.h>
 #include <linux/irq.h>
@@ -38,12 +39,6 @@
 #include "cputype.h"
 #include "clock.h"
 
-#ifdef CONFIG_CPU_MMP2
-#define MMP_CLOCK_FREQ		6500000
-#else
-#define MMP_CLOCK_FREQ		3250000
-#endif
-
 #define TIMERS_VIRT_BASE	TIMERS1_VIRT_BASE
 
 #define MAX_DELTA		(0xfffffffe)
@@ -189,19 +184,18 @@ static struct irqaction timer_irq = {
 	.dev_id		= &ckevt,
 };
 
-void __init timer_init(int irq)
+void __init timer_init(int irq, unsigned long rate)
 {
 	timer_config();
 
-	sched_clock_register(mmp_read_sched_clock, 32, MMP_CLOCK_FREQ);
+	sched_clock_register(mmp_read_sched_clock, 32, rate);
 
 	ckevt.cpumask = cpumask_of(0);
 
 	setup_irq(irq, &timer_irq);
 
-	clocksource_register_hz(&cksrc, MMP_CLOCK_FREQ);
-	clockevents_config_and_register(&ckevt, MMP_CLOCK_FREQ,
-					MIN_DELTA, MAX_DELTA);
+	clocksource_register_hz(&cksrc, rate);
+	clockevents_config_and_register(&ckevt, rate, MIN_DELTA, MAX_DELTA);
 }
 
 #ifdef CONFIG_OF
@@ -213,7 +207,9 @@ static const struct of_device_id mmp_timer_dt_ids[] = {
 void __init mmp_dt_init_timer(void)
 {
 	struct device_node *np;
+	struct clk *clk;
 	int irq, ret;
+	unsigned long rate;
 
 	np = of_find_matching_node(NULL, mmp_timer_dt_ids);
 	if (!np) {
@@ -221,6 +217,18 @@ void __init mmp_dt_init_timer(void)
 		goto out;
 	}
 
+	clk = of_clk_get(np, 0);
+	if (!IS_ERR(clk)) {
+		ret = clk_prepare_enable(clk);
+		if (ret)
+			goto out;
+		rate = clk_get_rate(clk) / 2;
+	} else if (cpu_is_pj4()) {
+		rate = 6500000;
+	} else {
+		rate = 3250000;
+	}
+
 	irq = irq_of_parse_and_map(np, 0);
 	if (!irq) {
 		ret = -EINVAL;
@@ -231,7 +239,7 @@ void __init mmp_dt_init_timer(void)
 		ret = -ENOMEM;
 		goto out;
 	}
-	timer_init(irq);
+	timer_init(irq, rate);
 	return;
 out:
 	pr_err("Failed to get timer from device tree with error:%d\n", ret);