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authorPawel Moll <pawel.moll@arm.com>2011-01-25 15:53:03 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2011-01-25 16:18:33 +0000
commitbaaece224570a935210a59257b5d9073e99843ea (patch)
tree1b0af1903ce4a58122473cca2d128ae1f56726c0 /arch
parente5310f611d17ed4e92e0d4e46fd9f6fb40e66df3 (diff)
ARM: 6635/2: Configure reference clock for Versatile Express timers
Timers on Versatile Express mainboard are used as system clock/event sources. Driver assumes that they are clocked with 1MHz signal. Old V2M firmware apparently configured it by default, but on newer boards one can observe that "sleep 1" command takes over 30 seconds to finish, as the timers are fed with 32kHz instead... This patch performs required magic and also removes code clearing timer's control registers, as exactly the same operations are performed by the timer driver few jiffies later. Signed-off-by: Pawel Moll <pawel.moll@arm.com> Tested-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/include/asm/hardware/sp810.h6
-rw-r--r--arch/arm/mach-vexpress/v2m.c9
2 files changed, 15 insertions, 0 deletions
diff --git a/arch/arm/include/asm/hardware/sp810.h b/arch/arm/include/asm/hardware/sp810.h
index a101f10bb5b..721847dc68a 100644
--- a/arch/arm/include/asm/hardware/sp810.h
+++ b/arch/arm/include/asm/hardware/sp810.h
@@ -50,6 +50,12 @@
#define SCPCELLID2 0xFF8
#define SCPCELLID3 0xFFC
+#define SCCTRL_TIMEREN0SEL_REFCLK (0 << 15)
+#define SCCTRL_TIMEREN0SEL_TIMCLK (1 << 15)
+
+#define SCCTRL_TIMEREN1SEL_REFCLK (0 << 17)
+#define SCCTRL_TIMEREN1SEL_TIMCLK (1 << 17)
+
static inline void sysctl_soft_reset(void __iomem *base)
{
/* writing any value to SCSYSSTAT reg will reset system */
diff --git a/arch/arm/mach-vexpress/v2m.c b/arch/arm/mach-vexpress/v2m.c
index a9ed3428a2f..1edae65a0e7 100644
--- a/arch/arm/mach-vexpress/v2m.c
+++ b/arch/arm/mach-vexpress/v2m.c
@@ -19,6 +19,7 @@
#include <asm/mach/time.h>
#include <asm/hardware/arm_timer.h>
#include <asm/hardware/timer-sp.h>
+#include <asm/hardware/sp810.h>
#include <mach/motherboard.h>
@@ -50,8 +51,16 @@ void __init v2m_map_io(struct map_desc *tile, size_t num)
static void __init v2m_timer_init(void)
{
+ u32 scctrl;
+
versatile_sched_clock_init(MMIO_P2V(V2M_SYS_24MHZ), 24000000);
+ /* Select 1MHz TIMCLK as the reference clock for SP804 timers */
+ scctrl = readl(MMIO_P2V(V2M_SYSCTL + SCCTRL));
+ scctrl |= SCCTRL_TIMEREN0SEL_TIMCLK;
+ scctrl |= SCCTRL_TIMEREN1SEL_TIMCLK;
+ writel(scctrl, MMIO_P2V(V2M_SYSCTL + SCCTRL));
+
writel(0, MMIO_P2V(V2M_TIMER0) + TIMER_CTRL);
writel(0, MMIO_P2V(V2M_TIMER1) + TIMER_CTRL);