For OMAP2+ devices, when using DMTIMERs for system timers (clock-events and
clock-source) the posted mode configuration of the timers is used. To allow
the compiler to optimise the functions for configuring and reading the system
timers, the posted flag variable is hard-coded with the value 1. To make it
clear that posted mode is being used add some definitions so that it is more
readable.
Add separate definitions for the clock-events and clock-source timers so that
we can change the posted mode of clock-events and clock-source independently.
Signed-off-by: Jon Hunter <jon-hunter@xxxxxx>
---
arch/arm/mach-omap2/timer.c | 26 +++++++++++++++++++-------
arch/arm/plat-omap/include/plat/dmtimer.h | 4 ++++
2 files changed, 23 insertions(+), 7 deletions(-)
diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
index 0758bae..28c6078 100644
--- a/arch/arm/mach-omap2/timer.c
+++ b/arch/arm/mach-omap2/timer.c
@@ -82,6 +82,13 @@
#define INCREMENTER_DENUMERATOR_RELOAD_OFFSET 0x14
#define NUMERATOR_DENUMERATOR_MASK 0xfffff000
+/*
+ * For clock-events timer, always use posted mode to
+ * minimise CPU overhead for configuring the timer.
+ */
+#define OMAP_CLKEVT_POSTEDMODE OMAP_TIMER_POSTED
+#define OMAP_CLKSRC_POSTEDMODE OMAP_TIMER_POSTED
+
/* Clockevent code */
static struct omap_dm_timer clkev;
@@ -107,7 +114,7 @@ static int omap2_gp_timer_set_next_event(unsigned long cycles,
struct clock_event_device *evt)
{
__omap_dm_timer_load_start(&clkev, OMAP_TIMER_CTRL_ST,
- 0xffffffff - cycles, 1);
+ 0xffffffff - cycles, OMAP_CLKEVT_POSTEDMODE);
return 0;
}
@@ -117,7 +124,7 @@ static void omap2_gp_timer_set_mode(enum clock_event_mode mode,
{
u32 period;
- __omap_dm_timer_stop(&clkev, 1, clkev.rate);
+ __omap_dm_timer_stop(&clkev, OMAP_CLKEVT_POSTEDMODE, clkev.rate);
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
@@ -125,10 +132,12 @@ static void omap2_gp_timer_set_mode(enum clock_event_mode mode,
period -= 1;
/* Looks like we need to first set the load value separately */
__omap_dm_timer_write(&clkev, OMAP_TIMER_LOAD_REG,
- 0xffffffff - period, 1);
+ 0xffffffff - period,
+ OMAP_CLKEVT_POSTEDMODE);
__omap_dm_timer_load_start(&clkev,
OMAP_TIMER_CTRL_AR | OMAP_TIMER_CTRL_ST,
- 0xffffffff - period, 1);
+ 0xffffffff - period,
+ OMAP_CLKEVT_POSTEDMODE);
break;
case CLOCK_EVT_MODE_ONESHOT:
break;
@@ -358,7 +367,8 @@ static bool use_gptimer_clksrc;
*/
static cycle_t clocksource_read_cycles(struct clocksource *cs)
{
- return (cycle_t)__omap_dm_timer_read_counter(&clksrc, 1);
+ return (cycle_t)__omap_dm_timer_read_counter(&clksrc,
+ OMAP_CLKSRC_POSTEDMODE);
}
static struct clocksource clocksource_gpt = {
@@ -372,7 +382,8 @@ static struct clocksource clocksource_gpt = {
static u32 notrace dmtimer_read_sched_clock(void)
{
if (clksrc.reserved)
- return __omap_dm_timer_read_counter(&clksrc, 1);
+ return __omap_dm_timer_read_counter(&clksrc,
+ OMAP_CLKSRC_POSTEDMODE);
return 0;
}
@@ -454,7 +465,8 @@ static void __init omap2_gptimer_clocksource_init(int gptimer_id,
BUG_ON(res);
__omap_dm_timer_load_start(&clksrc,
- OMAP_TIMER_CTRL_ST | OMAP_TIMER_CTRL_AR, 0, 1);
+ OMAP_TIMER_CTRL_ST | OMAP_TIMER_CTRL_AR, 0,
+ OMAP_CLKSRC_POSTEDMODE);
setup_sched_clock(dmtimer_read_sched_clock, 32, clksrc.rate);
if (clocksource_register_hz(&clocksource_gpt, clksrc.rate))
diff --git a/arch/arm/plat-omap/include/plat/dmtimer.h b/arch/arm/plat-omap/include/plat/dmtimer.h
index 348f855..835c3bdf 100644
--- a/arch/arm/plat-omap/include/plat/dmtimer.h
+++ b/arch/arm/plat-omap/include/plat/dmtimer.h
@@ -55,6 +55,10 @@
#define OMAP_TIMER_TRIGGER_OVERFLOW 0x01
#define OMAP_TIMER_TRIGGER_OVERFLOW_AND_COMPARE 0x02
+/* posted mode types */
+#define OMAP_TIMER_NONPOSTED 0x00
+#define OMAP_TIMER_POSTED 0x01
+
/* timer capabilities used in hwmod database */
#define OMAP_TIMER_SECURE 0x80000000
#define OMAP_TIMER_ALWON 0x40000000
--
1.7.9.5
--
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