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authorKevin Hilman <khilman@mvista.com>2007-03-08 20:32:19 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2007-04-21 21:02:55 +0100
commit075192ae807579448afcc0833bd349ccce057825 (patch)
tree5627ae9d65bc8791793fde1bc2ad8f62bc015e44 /arch/arm/plat-omap/common.c
parent89df127246f23add865f4a8f719c990e41151843 (diff)
downloadlinux-linaro-stable-075192ae807579448afcc0833bd349ccce057825.tar.gz
[ARM] 4262/1: OMAP: clocksource and clockevent support
Update OMAP1 to enable support for hrtimers and dynticks by using new clocksource and clockevent infrastructure. Signed-off-by: Kevin Hilman <khilman@mvista.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/plat-omap/common.c')
-rw-r--r--arch/arm/plat-omap/common.c50
1 files changed, 50 insertions, 0 deletions
diff --git a/arch/arm/plat-omap/common.c b/arch/arm/plat-omap/common.c
index 57b7b93674a4..fecd3d625995 100644
--- a/arch/arm/plat-omap/common.c
+++ b/arch/arm/plat-omap/common.c
@@ -156,3 +156,53 @@ static int __init omap_add_serial_console(void)
return add_preferred_console("ttyS", line, opt);
}
console_initcall(omap_add_serial_console);
+
+
+/*
+ * 32KHz clocksource ... always available, on pretty most chips except
+ * OMAP 730 and 1510. Other timers could be used as clocksources, with
+ * higher resolution in free-running counter modes (e.g. 12 MHz xtal),
+ * but systems won't necessarily want to spend resources that way.
+ */
+
+#if defined(CONFIG_ARCH_OMAP16XX)
+#define TIMER_32K_SYNCHRONIZED 0xfffbc410
+#elif defined(CONFIG_ARCH_OMAP24XX)
+#define TIMER_32K_SYNCHRONIZED 0x48004010
+#endif
+
+#ifdef TIMER_32K_SYNCHRONIZED
+
+#include <linux/clocksource.h>
+
+static cycle_t omap_32k_read(void)
+{
+ return omap_readl(TIMER_32K_SYNCHRONIZED);
+}
+
+static struct clocksource clocksource_32k = {
+ .name = "32k_counter",
+ .rating = 250,
+ .read = omap_32k_read,
+ .mask = CLOCKSOURCE_MASK(32),
+ .shift = 10,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static int __init omap_init_clocksource_32k(void)
+{
+ static char err[] __initdata = KERN_ERR
+ "%s: can't register clocksource!\n";
+
+ if (cpu_is_omap16xx() || cpu_is_omap24xx()) {
+ clocksource_32k.mult = clocksource_hz2mult(32768,
+ clocksource_32k.shift);
+
+ if (clocksource_register(&clocksource_32k))
+ printk(err, clocksource_32k.name);
+ }
+ return 0;
+}
+arch_initcall(omap_init_clocksource_32k);
+
+#endif /* TIMER_32K_SYNCHRONIZED */