PM debug: allow configurable wakeup from suspend on OMAP GPtimer
Using debugfs, export a configurable wakeup timer to be used to
wakeup system from suspend.
If a non-zero value is written to
/debug/pm_debug/wakeup_timer_seconds, A timer wakeup event will wake
the system and resume after the configured number of seconds.
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index ade2e4a..ff818aa 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -36,6 +36,7 @@
#include <plat/prcm.h>
#include <plat/gpmc.h>
#include <plat/dma.h>
+#include <plat/dmtimer.h>
#include <asm/tlbflush.h>
@@ -60,6 +61,7 @@
u32 enable_off_mode;
u32 sleep_while_idle;
+u32 wakeup_timer_seconds;
struct power_state {
struct powerdomain *pwrdm;
@@ -535,6 +537,22 @@
#ifdef CONFIG_SUSPEND
static suspend_state_t suspend_state;
+static void omap2_pm_wakeup_on_timer(u32 seconds)
+{
+ u32 tick_rate, cycles;
+
+ if (!seconds)
+ return;
+
+ tick_rate = clk_get_rate(omap_dm_timer_get_fclk(gptimer_wakeup));
+ cycles = tick_rate * seconds;
+ omap_dm_timer_stop(gptimer_wakeup);
+ omap_dm_timer_set_load_start(gptimer_wakeup, 0, 0xffffffff - cycles);
+
+ pr_info("PM: Resume timer in %d secs (%d ticks at %d ticks/sec.)\n",
+ seconds, cycles, tick_rate);
+}
+
static int omap3_pm_prepare(void)
{
disable_hlt();
@@ -546,6 +564,9 @@
struct power_state *pwrst;
int state, ret = 0;
+ if (wakeup_timer_seconds)
+ omap2_pm_wakeup_on_timer(wakeup_timer_seconds);
+
/* Read current next_pwrsts */
list_for_each_entry(pwrst, &pwrst_list, node)
pwrst->saved_state = pwrdm_read_next_pwrst(pwrst->pwrdm);