ARM: EXYNOS: Fix support of Exynos4210 rev0 SoC

This patch extends exynos_init_time() function to handle Exynos4210
rev0 SoC, which differs in availability of system timers and needs
different clocksource initialization.

This makes it possible to use exynos_init_time() function as init_time
callback for all Exynos-based boards, including Universal_C210, which
originally had to use samsung_timer_init().

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
diff --git a/arch/arm/mach-exynos/common.c b/arch/arm/mach-exynos/common.c
index 745e304..a2d2012 100644
--- a/arch/arm/mach-exynos/common.c
+++ b/arch/arm/mach-exynos/common.c
@@ -10,12 +10,14 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/bitops.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/irqchip.h>
 #include <linux/io.h>
 #include <linux/device.h>
 #include <linux/gpio.h>
+#include <clocksource/samsung_pwm.h>
 #include <linux/sched.h>
 #include <linux/serial_core.h>
 #include <linux/of.h>
@@ -302,6 +304,13 @@
 	},
 };
 
+static struct samsung_pwm_variant exynos4_pwm_variant = {
+	.bits		= 32,
+	.div_base	= 0,
+	.has_tint_cstat	= true,
+	.tclk_mask	= 0,
+};
+
 void exynos4_restart(char mode, const char *cmd)
 {
 	__raw_writel(0x1, S5P_SWRESET);
@@ -442,8 +451,20 @@
 	iotable_init(exynos5440_iodesc0, ARRAY_SIZE(exynos5440_iodesc0));
 }
 
+void __init exynos_set_timer_source(u8 channels)
+{
+	exynos4_pwm_variant.output_mask = BIT(SAMSUNG_PWM_NUM) - 1;
+	exynos4_pwm_variant.output_mask &= ~channels;
+}
+
 void __init exynos_init_time(void)
 {
+	unsigned int timer_irqs[SAMSUNG_PWM_NUM] = {
+		EXYNOS4_IRQ_TIMER0_VIC, EXYNOS4_IRQ_TIMER1_VIC,
+		EXYNOS4_IRQ_TIMER2_VIC, EXYNOS4_IRQ_TIMER3_VIC,
+		EXYNOS4_IRQ_TIMER4_VIC,
+	};
+
 	if (of_have_populated_dt()) {
 #ifdef CONFIG_OF
 		of_clk_init(NULL);
@@ -455,7 +476,14 @@
 		exynos4_clk_init(NULL, !soc_is_exynos4210(), S5P_VA_CMU, readl(S5P_VA_CHIPID + 8) & 1);
 		exynos4_clk_register_fixed_ext(xxti_f, xusbxti_f);
 #endif
-		mct_init(S5P_VA_SYSTIMER, EXYNOS4_IRQ_MCT_G0, EXYNOS4_IRQ_MCT_L0, EXYNOS4_IRQ_MCT_L1);
+#ifdef CONFIG_CLKSRC_SAMSUNG_PWM
+		if (soc_is_exynos4210() && samsung_rev() == EXYNOS4210_REV_0)
+			samsung_pwm_clocksource_init(S3C_VA_TIMER,
+					timer_irqs, &exynos4_pwm_variant);
+		else
+#endif
+			mct_init(S5P_VA_SYSTIMER, EXYNOS4_IRQ_MCT_G0,
+					EXYNOS4_IRQ_MCT_L0, EXYNOS4_IRQ_MCT_L1);
 	}
 }