Ashwin Bihari <abihari@xxxxxxxxx> writes:
> I need to implement a timer as a wake up trigger while my custom board
> is in the suspended state. I read in the TRM that all of the GPTIMERs
> have the capability of generating a wake up interrupt. I'm using the
> 2.6.28-rc8 PM Kernel which contains the patch to enable all the
> GPTIMERS as wake up sources.
Try the patch below on the current PM branch. I use this for
debugging PM code when no other wakeup sources (keypad, UART, etc. are
working.)
Kevin
>From bf81b7cce8967a425f1aa3d73782c1eb0367ce1a Mon Sep 17 00:00:00 2001
From: Kevin Hilman <khilman@xxxxxxxxxxxxxxxxxxx>
Date: Fri, 24 Apr 2009 16:13:47 -0700
Subject: [PATCH] OMAP3: PM: Add feature to wake from suspend on timer
If a non-zero value is written to /sys/power/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@xxxxxxxxxxxxxxxxxxx>
---
arch/arm/mach-omap2/pm.c | 15 +++++++++++++--
arch/arm/mach-omap2/pm.h | 3 +++
arch/arm/mach-omap2/pm34xx.c | 22 ++++++++++++++++++++++
arch/arm/mach-omap2/timer-gp.c | 2 ++
4 files changed, 40 insertions(+), 2 deletions(-)
diff --git a/arch/arm/mach-omap2/pm.c b/arch/arm/mach-omap2/pm.c
index 50d95cd..dde0af3 100644
--- a/arch/arm/mach-omap2/pm.c
+++ b/arch/arm/mach-omap2/pm.c
@@ -42,6 +42,7 @@ unsigned short enable_dyn_sleep;
unsigned short clocks_off_while_idle;
unsigned short enable_off_mode;
unsigned short voltage_off_while_idle;
+unsigned short wakeup_timer_seconds;
atomic_t sleep_block = ATOMIC_INIT(0);
static ssize_t idle_show(struct kobject *, struct kobj_attribute *, char *);
@@ -76,6 +77,9 @@ static struct kobj_attribute vdd2_lock_attr =
#endif
+static struct kobj_attribute wakeup_timer_seconds_attr =
+ __ATTR(wakeup_timer_seconds, 0644, idle_show, idle_store);
+
static ssize_t idle_show(struct kobject *kobj, struct kobj_attribute *attr,
char *buf)
{
@@ -87,6 +91,8 @@ static ssize_t idle_show(struct kobject *kobj, struct kobj_attribute *attr,
return sprintf(buf, "%hu\n", enable_off_mode);
else if (attr == &voltage_off_while_idle_attr)
return sprintf(buf, "%hu\n", voltage_off_while_idle);
+ else if (attr == &wakeup_timer_seconds_attr)
+ return sprintf(buf, "%hu\n", wakeup_timer_seconds);
else
return -EINVAL;
}
@@ -96,8 +102,7 @@ static ssize_t idle_store(struct kobject *kobj, struct kobj_attribute *attr,
{
unsigned short value;
- if (sscanf(buf, "%hu", &value) != 1 ||
- (value != 0 && value != 1)) {
+ if (sscanf(buf, "%hu", &value) != 1) {
printk(KERN_ERR "idle_store: Invalid value\n");
return -EINVAL;
}
@@ -109,6 +114,8 @@ static ssize_t idle_store(struct kobject *kobj, struct kobj_attribute *attr,
} else if (attr == &enable_off_mode_attr) {
enable_off_mode = value;
omap3_pm_off_mode_enable(enable_off_mode);
+ } else if (attr == &wakeup_timer_seconds_attr) {
+ wakeup_timer_seconds = value;
} else if (attr == &voltage_off_while_idle_attr) {
voltage_off_while_idle = value;
if (voltage_off_while_idle)
@@ -255,6 +262,10 @@ static int __init omap_pm_init(void)
printk(KERN_ERR "sysfs_create_file failed: %d\n", error);
return error;
}
+ error = sysfs_create_file(power_kobj,
+ &wakeup_timer_seconds_attr.attr);
+ if (error)
+ printk(KERN_ERR "sysfs_create_file failed: %d\n", error);
#ifdef CONFIG_OMAP_PM_SRF
error = sysfs_create_file(power_kobj,
&vdd1_opp_attr.attr);
diff --git a/arch/arm/mach-omap2/pm.h b/arch/arm/mach-omap2/pm.h
index 942a990..66effed 100644
--- a/arch/arm/mach-omap2/pm.h
+++ b/arch/arm/mach-omap2/pm.h
@@ -30,6 +30,9 @@ extern unsigned short voltage_off_while_idle;
extern atomic_t sleep_block;
extern void *omap3_secure_ram_storage;
+extern unsigned short wakeup_timer_seconds;
+extern struct omap_dm_timer *gptimer_wakeup;
+
extern void omap2_block_sleep(void);
extern void omap2_allow_sleep(void);
#ifdef CONFIG_ARCH_OMAP3
diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index d8795b5..3f41417 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -26,6 +26,7 @@
#include <linux/module.h>
#include <linux/list.h>
#include <linux/err.h>
+#include <linux/clk.h>
#include <mach/gpio.h>
#include <mach/sram.h>
@@ -41,6 +42,8 @@
#include <mach/dma.h>
#include <mach/gpmc.h>
#include <mach/dma.h>
+#include <mach/dmtimer.h>
+
#include <asm/tlbflush.h>
#include "cm.h"
@@ -552,6 +555,22 @@ out:
static void (*saved_idle)(void);
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)
{
saved_idle = pm_idle;
@@ -564,6 +583,9 @@ static int omap3_pm_suspend(void)
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);
diff --git a/arch/arm/mach-omap2/timer-gp.c b/arch/arm/mach-omap2/timer-gp.c
index 8351a34..83dd4b1 100644
--- a/arch/arm/mach-omap2/timer-gp.c
+++ b/arch/arm/mach-omap2/timer-gp.c
@@ -38,6 +38,7 @@
static struct omap_dm_timer *gptimer;
static struct clock_event_device clockevent_gpt;
+struct omap_dm_timer *gptimer_wakeup;
static irqreturn_t omap2_gp_timer_interrupt(int irq, void *dev_id)
{
@@ -101,6 +102,7 @@ static void __init omap2_gp_clockevent_init(void)
gptimer = omap_dm_timer_request_specific(CONFIG_OMAP_TICK_GPTIMER);
BUG_ON(gptimer == NULL);
+ gptimer_wakeup = gptimer;
#if defined(CONFIG_OMAP_32K_TIMER)
omap_dm_timer_set_source(gptimer, OMAP_TIMER_SRC_32_KHZ);
--
1.6.2.2
--
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