OMAP3: PM: move device-specific special cases from PM core into CPUidle
In an effort to simplify the core idle path, move any device-specific
special case handling from the core PM idle path into the CPUidle
pre-idle checking path.
This keeps the core, interrupts-disabled idle path streamlined and
independent of any device-specific handling, and also allows CPUidle
to do the checking only for certain C-states as needed. This patch
has the device checks in place for all states with the CHECK_BM flag,
namely all states >= C2.
This patch was inspired by a similar patch written by Tero Kristo as
part of a larger series to add INACTIVE state support.
NOTE: This is a baby-step towards decoupling device idle (or system
idle) from CPU idle. Eventually, CPUidle should only manage the CPU,
and device/system idle should be managed elsewhere.
Cc: Tero Kristo <tero.kristo@nokia.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
diff --git a/arch/arm/mach-omap2/cpuidle34xx.c b/arch/arm/mach-omap2/cpuidle34xx.c
index 3d3d035..8ea012e 100644
--- a/arch/arm/mach-omap2/cpuidle34xx.c
+++ b/arch/arm/mach-omap2/cpuidle34xx.c
@@ -60,7 +60,8 @@
struct omap3_processor_cx omap3_power_states[OMAP3_MAX_STATES];
struct omap3_processor_cx current_cx_state;
-struct powerdomain *mpu_pd, *core_pd;
+struct powerdomain *mpu_pd, *core_pd, *per_pd;
+struct powerdomain *cam_pd;
/*
* The latencies/thresholds for various C states have
@@ -233,14 +234,62 @@
struct cpuidle_state *state)
{
struct cpuidle_state *new_state = next_valid_state(dev, state);
+ u32 core_next_state, per_next_state = 0, per_saved_state = 0;
+ u32 cam_state;
+ struct omap3_processor_cx *cx;
+ int ret;
if ((state->flags & CPUIDLE_FLAG_CHECK_BM) && omap3_idle_bm_check()) {
BUG_ON(!dev->safe_state);
new_state = dev->safe_state;
+ goto select_state;
}
+ cx = cpuidle_get_statedata(state);
+ core_next_state = cx->core_state;
+
+ /*
+ * FIXME: we currently manage device-specific idle states
+ * for PER and CORE in combination with CPU-specific
+ * idle states. This is wrong, and device-specific
+ * idle managment needs to be separated out into
+ * its own code.
+ */
+
+ /*
+ * Prevent idle completely if CAM is active.
+ * CAM does not have wakeup capability in OMAP3.
+ */
+ cam_state = pwrdm_read_pwrst(cam_pd);
+ if (cam_state == PWRDM_POWER_ON) {
+ new_state = dev->safe_state;
+ goto select_state;
+ }
+
+ /*
+ * Prevent PER off if CORE is not in retention or off as this
+ * would disable PER wakeups completely.
+ */
+ per_next_state = per_saved_state = pwrdm_read_next_pwrst(per_pd);
+ if ((per_next_state == PWRDM_POWER_OFF) &&
+ (core_next_state > PWRDM_POWER_RET)) {
+ per_next_state = PWRDM_POWER_RET;
+ pwrdm_set_next_pwrst(per_pd, per_next_state);
+ }
+
+ /* Are we changing PER target state? */
+ if (per_next_state != per_saved_state)
+ pwrdm_set_next_pwrst(per_pd, per_next_state);
+
+select_state:
dev->last_state = new_state;
- return omap3_enter_idle(dev, new_state);
+ ret = omap3_enter_idle(dev, new_state);
+
+ /* Restore original PER state if it was modified */
+ if (per_next_state != per_saved_state)
+ pwrdm_set_next_pwrst(per_pd, per_saved_state);
+
+ return ret;
}
DEFINE_PER_CPU(struct cpuidle_device, omap3_idle_dev);
@@ -328,7 +377,8 @@
cpuidle_params_table[OMAP3_STATE_C2].threshold;
omap3_power_states[OMAP3_STATE_C2].mpu_state = PWRDM_POWER_ON;
omap3_power_states[OMAP3_STATE_C2].core_state = PWRDM_POWER_ON;
- omap3_power_states[OMAP3_STATE_C2].flags = CPUIDLE_FLAG_TIME_VALID;
+ omap3_power_states[OMAP3_STATE_C2].flags = CPUIDLE_FLAG_TIME_VALID |
+ CPUIDLE_FLAG_CHECK_BM;
/* C3 . MPU CSWR + Core inactive */
omap3_power_states[OMAP3_STATE_C3].valid =
@@ -426,6 +476,8 @@
mpu_pd = pwrdm_lookup("mpu_pwrdm");
core_pd = pwrdm_lookup("core_pwrdm");
+ per_pd = pwrdm_lookup("per_pwrdm");
+ cam_pd = pwrdm_lookup("cam_pwrdm");
omap_init_power_states();
cpuidle_register_driver(&omap3_idle_driver);