This is a non-blocking interface that specifies which suspend state toenter when no wakelocks are locked. A special state, "on", stops theprocess by locking the "main" wakelock.
If early-suspend support is enabled, early suspend handlers will be calledwhen a state other than "on" is written. When writing "on", the corresondingresume handlers are called.
Signed-off-by: Arve Hjønnevåg <arve@xxxxxxxxxxx>--- kernel/power/main.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 74 insertions(+), 0 deletions(-)
diff --git a/kernel/power/main.c b/kernel/power/main.cindex e2aae3e..676a8b0 100644--- a/kernel/power/main.c+++ b/kernel/power/main.c@@ -22,6 +22,7 @@ #include <linux/freezer.h> #include <linux/vmstat.h> #include <linux/syscalls.h>+#include <linux/wakelock.h> #include "power.h" @@ -388,6 +389,9 @@ static void suspend_finish(void) static const char * const pm_states[PM_SUSPEND_MAX] = {+#ifdef CONFIG_WAKELOCK+ [PM_SUSPEND_ON] = "on",+#endif [PM_SUSPEND_STANDBY] = "standby", [PM_SUSPEND_MEM] = "mem", };@@ -545,6 +549,73 @@ static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr, power_attr(state); #endif +/**+ * request_state - control system power state.+ *+ * This is similar to state, but it does not block until the system+ * resumes, and it will try to re-enter the state until another state is+ * requsted. Wakelocks are respected and the requested state will only+ * be entered when no wakelocks are held. Write "on" to cancel.+ *+ * If CONFIG_EARLYSUSPEND is set, early_suspend hooks are called when+ * the requested state changes to or from "on"+ */++#ifdef CONFIG_WAKELOCK+static ssize_t request_state_show(struct kobject *kobj, struct kobj_attribute *attr,+ char *buf)+{+ char *s = buf;+ int i;++ for (i = 0; i < PM_SUSPEND_MAX; i++) {+ if (pm_states[i] && valid_state(i))+ s += sprintf(s,"%s ", pm_states[i]);+ }+ if (s != buf)+ /* convert the last space to a newline */+ *(s-1) = '\n';+ return (s - buf);+}++static ssize_t request_state_store(struct kobject *kobj, struct kobj_attribute *attr,+ const char *buf, size_t n)+{+ suspend_state_t state = PM_SUSPEND_ON;+ const char * const *s;+ char *p;+ int len;+ int error = -EINVAL;++ p = memchr(buf, '\n', n);+ len = p ? p - buf : n;++ for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) {+ if (*s && len == strlen(*s) && !strncmp(buf, *s, len))+ break;+ }+ if (state < PM_SUSPEND_MAX && *s)+ if (state == PM_SUSPEND_ON || valid_state(state)) {+ error = 0;+#ifdef CONFIG_EARLYSUSPEND+ request_suspend_state(state);+#else+ if (!mutex_trylock(&pm_mutex))+ return -EBUSY;+ requested_suspend_state = state;+ if (state == PM_SUSPEND_ON)+ wake_lock(&main_wake_lock);+ else+ wake_unlock(&main_wake_lock);+ mutex_unlock(&pm_mutex);+#endif+ }+ return error ? error : n;+}++power_attr(request_state);+#endif+ #ifdef CONFIG_PM_TRACE int pm_trace_enabled; @@ -574,6 +645,9 @@ static struct attribute * g[] = { #ifndef CONFIG_DISABLE_SYS_POWER_STATE &state_attr.attr, #endif+#ifdef CONFIG_WAKELOCK+ &request_state_attr.attr,+#endif #ifdef CONFIG_PM_TRACE &pm_trace_attr.attr, #endif-- 1.6.1
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