[ARM] rtc-sa1100: don't assume CLOCK_TICK_RATE to be a constant

As Nicolas and Russell pointed out, CLOCK_TICK_RATE is no more
a constant on PXA when multiple processors and platforms are
selected, change TIMER_FREQ in rtc-sa1100.c into a variable.

Since the code to decide the clock tick rate is re-used from
timer.c, introduce a common get_clock_tick_rate() for this.

Signed-off-by: Eric Miao <eric.miao@marvell.com>
Acked-by: Nicolas Pitre <nico@marvell.com>

4 files changed, 27 insertions, 9 deletions

diff --git a/arch/arm/mach-pxa/generic.c b/arch/arm/mach-pxa/generic.c
index 85ed0b33331f..0ccc91c92c44 100644
--- a/arch/arm/mach-pxa/generic.c
+++ b/arch/arm/mach-pxa/generic.c
@@ -24,6 +24,7 @@
 #include <asm/system.h>
 #include <asm/pgtable.h>
 #include <asm/mach/map.h>
+#include <asm/mach-types.h>
 
 #include <mach/pxa-regs.h>
 #include <mach/reset.h>
@@ -39,6 +40,21 @@ void clear_reset_status(unsigned int mask)
                 pxa3xx_clear_reset_status(mask);
 }
 
+unsigned long get_clock_tick_rate(void)
+{
+        unsigned long clock_tick_rate;
+
+        if (cpu_is_pxa25x())
+                clock_tick_rate = 3686400;
+        else if (machine_is_mainstone())
+                clock_tick_rate = 3249600;
+        else
+                clock_tick_rate = 3250000;
+
+        return clock_tick_rate;
+}
+EXPORT_SYMBOL(get_clock_tick_rate);
+
 /*
  * Get the clock frequency as reflected by CCCR and the turbo flag.
  * We assume these values have been applied via a fcs.
diff --git a/arch/arm/mach-pxa/include/mach/hardware.h b/arch/arm/mach-pxa/include/mach/hardware.h
index e2d6784aa7ef..c666796911cb 100644
--- a/arch/arm/mach-pxa/include/mach/hardware.h
+++ b/arch/arm/mach-pxa/include/mach/hardware.h
@@ -291,6 +291,8 @@
  */
 extern unsigned int get_memclk_frequency_10khz(void);
 
+/* return the clock tick rate of the OS timer */
+extern unsigned long get_clock_tick_rate(void);
 #endif
 
 #if defined(CONFIG_MACH_ARMCORE) && defined(CONFIG_PCI)
diff --git a/arch/arm/mach-pxa/include/mach/timex.h b/arch/arm/mach-pxa/include/mach/timex.h
index b05fc6683c47..af6760a50e1a 100644
--- a/arch/arm/mach-pxa/include/mach/timex.h
+++ b/arch/arm/mach-pxa/include/mach/timex.h
@@ -10,6 +10,14 @@
  * published by the Free Software Foundation.
  */
 
+/* Various drivers are still using the constant of CLOCK_TICK_RATE, for
+ * those drivers to at least work, the definition is provided here.
+ *
+ * NOTE: this is no longer accurate when multiple processors and boards
+ * are selected, newer drivers should not depend on this any more.  Use
+ * either the clocksource/clockevent or get this at run-time by calling
+ * get_clock_tick_rate() (as defined in generic.c).
+ */
 
 #if defined(CONFIG_PXA25x)
 /* PXA250/210 timer base */
diff --git a/arch/arm/mach-pxa/time.c b/arch/arm/mach-pxa/time.c
index f8a9a62959e5..986d494a1834 100644
--- a/arch/arm/mach-pxa/time.c
+++ b/arch/arm/mach-pxa/time.c
@@ -23,7 +23,6 @@
 #include <asm/mach/irq.h>
 #include <asm/mach/time.h>
 #include <mach/pxa-regs.h>
-#include <asm/mach-types.h>
 
 /*
  * This is PXA's sched_clock implementation. This has a resolution
@@ -150,18 +149,11 @@ static struct irqaction pxa_ost0_irq = {
 
 static void __init pxa_timer_init(void)
 {
-        unsigned long clock_tick_rate;
+        unsigned long clock_tick_rate = get_clock_tick_rate();
 
         OIER = 0;
         OSSR = OSSR_M0 | OSSR_M1 | OSSR_M2 | OSSR_M3;
 
-        if (cpu_is_pxa25x())
-                clock_tick_rate = 3686400;
-        else if (machine_is_mainstone())
-                clock_tick_rate = 3249600;
-        else
-                clock_tick_rate = 3250000;
-
         set_oscr2ns_scale(clock_tick_rate);
 
         ckevt_pxa_osmr0.mult =