[PATCH V2] ARM: OMAP5/DRA7: realtime_counter: Configure CNTFRQ register

[PATCH V2] ARM: OMAP5/DRA7: realtime_counter: Configure CNTFRQ register

[Sricharan R]

The realtime counter called master counter, produces the count
used by the private timer peripherals in the MPU_CLUSTER. The
CNTFRQ per cpu register is used to denote the frequency of the counter.
Currently the frequency value is passed from the
DT file, but this is not scalable when we have other non-DT guest
OS. This register must be set to the right value by the
secure rom code. Setting this register helps in propagating the right
frequency value across OSes.

More discussions and the reason for adding this in a non-DT
way can be seen from below.
http://www.mail-archive.com/linux-omap at vger.kernel.org/msg93832.html

So configuring this secure register for all the cpus here.

Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Nishanth Menon <nm@ti.com>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sricharan R <r.sricharan@ti.com>
Tested-by: Nishanth Menon <nm@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
---
 [V2] Updated commit log

 arch/arm/mach-omap2/omap-secure.h |    2 ++
 arch/arm/mach-omap2/omap-smp.c    |    9 +++++++++
 arch/arm/mach-omap2/timer.c       |    6 ++++++
 3 files changed, 17 insertions(+)

diff --git a/arch/arm/mach-omap2/omap-secure.h b/arch/arm/mach-omap2/omap-secure.h
index a171a5a..4de9a00 100644
--- a/arch/arm/mach-omap2/omap-secure.h
+++ b/arch/arm/mach-omap2/omap-secure.h
@@ -51,6 +51,8 @@
 
 #define OMAP5_MON_AMBA_IF_INDEX		0x108
 
+#define OMAP5_DRA7_MON_SET_CNTFRQ_INDEX	0x109
+
 /* Secure PPA(Primary Protected Application) APIs */
 #define OMAP4_PPA_L2_POR_INDEX		0x23
 #define OMAP4_PPA_CPU_ACTRL_SMP_INDEX	0x25
diff --git a/arch/arm/mach-omap2/omap-smp.c b/arch/arm/mach-omap2/omap-smp.c
index 98a1146..00873b4 100644
--- a/arch/arm/mach-omap2/omap-smp.c
+++ b/arch/arm/mach-omap2/omap-smp.c
@@ -41,6 +41,8 @@
 
 u16 pm44xx_errata;
 
+extern unsigned long arch_timer_freq;
+
 /* SCU base address */
 static void __iomem *scu_base;
 
@@ -66,6 +68,13 @@ static void __cpuinit omap4_secondary_init(unsigned int cpu)
 							4, 0, 0, 0, 0, 0);
 
 	/*
+	 * Configure the CNTFRQ register for the secondary cpu's which
+	 * indicates the frequency of the cpu local timers.
+	 */
+	if (soc_is_omap54xx() || soc_is_dra7xx())
+		omap_smc1(OMAP5_DRA7_MON_SET_CNTFRQ_INDEX, arch_timer_freq);
+
+	/*
 	 * Synchronise with the boot thread.
 	 */
 	spin_lock(&boot_lock);
diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
index fd9238d..2c499f3 100644
--- a/arch/arm/mach-omap2/timer.c
+++ b/arch/arm/mach-omap2/timer.c
@@ -55,6 +55,7 @@
 #include "soc.h"
 #include "common.h"
 #include "powerdomain.h"
+#include "omap-secure.h"
 
 #define REALTIME_COUNTER_BASE				0x48243200
 #define INCREMENTER_NUMERATOR_OFFSET			0x10
@@ -65,6 +66,7 @@
 
 static struct omap_dm_timer clkev;
 static struct clock_event_device clockevent_gpt;
+unsigned long arch_timer_freq;
 
 static irqreturn_t omap2_gp_timer_interrupt(int irq, void *dev_id)
 {
@@ -546,7 +548,11 @@ static void __init realtime_counter_init(void)
 	reg |= den;
 	__raw_writel(reg, base + INCREMENTER_DENUMERATOR_RELOAD_OFFSET);
 
+	arch_timer_freq = (rate / den) * num;
+
 	iounmap(base);
+
+	omap_smc1(OMAP5_DRA7_MON_SET_CNTFRQ_INDEX, arch_timer_freq);
 }
 #else
 static inline void __init realtime_counter_init(void)
-- 
1.7.9.5