ARM: EXYNOS4: Update HRT for supporting PM

This patch updates HRT driver for supporting PM.
The resume function of PWM4 timer which is used clocksource is needed
when kernel is resuming for restarting.
Signed-off-by: Jaecheol Lee <jc.lee@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

arch/arm/mach-exynos4/time.c

@@ -206,12 +206,28 @@ static cycle_t exynos4_pwm4_read(struct clocksource *cs)
 	return (cycle_t) ~__raw_readl(S3C_TIMERREG(0x40));
 }
 
+static void exynos4_pwm4_resume(struct clocksource *cs)
+{
+	unsigned long pclk;
+
+	pclk = clk_get_rate(timerclk);
+
+	clk_set_rate(tdiv4, pclk / 2);
+	clk_set_parent(tin4, tdiv4);
+
+	exynos4_pwm_init(4, ~0);
+	exynos4_pwm_start(4, 1);
+}
+
 struct clocksource pwm_clocksource = {
 	.name		= "pwm_timer4",
 	.rating		= 250,
 	.read		= exynos4_pwm4_read,
 	.mask		= CLOCKSOURCE_MASK(32),
 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS ,
+#ifdef CONFIG_PM
+	.resume		= exynos4_pwm4_resume,
+#endif
 };
 
 static void __init exynos4_clocksource_init(void)