From: Tero Kristo <tero.kristo@xxxxxxxxx>
Following checks are made (and their reasoning):
- If CAM domain is active, prevent idle completely
* CAM pwrdm does not have HW wakeup capability
- If PER is likely to remain on, prevent PER off
* Saves on unnecessary context save/restore
- If CORE domain is active, prevent PER off-mode
* PER off in this case would prevent wakeups from PER completely
- Only allow CORE off, if all peripheral domains are off
* CORE off will cause a chipwide reset
Also, enabled CHECK_BM flag for C2, as this is needed for the camera case.
Signed-off-by: Tero Kristo <tero.kristo@xxxxxxxxx>
---
arch/arm/mach-omap2/cpuidle34xx.c | 118 ++++++++++++++++++++++++++++++++++--
1 files changed, 111 insertions(+), 7 deletions(-)
diff --git a/arch/arm/mach-omap2/cpuidle34xx.c b/arch/arm/mach-omap2/cpuidle34xx.c
index 4a81ef1..dad64a9 100644
--- a/arch/arm/mach-omap2/cpuidle34xx.c
+++ b/arch/arm/mach-omap2/cpuidle34xx.c
@@ -58,7 +58,8 @@ struct omap3_processor_cx {
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, *iva2_pd;
+struct powerdomain *sgx_pd, *usb_pd, *cam_pd, *dss_pd;
/*
* The latencies/thresholds for various C states have
@@ -92,6 +93,22 @@ static int omap3_idle_bm_check(void)
}
/**
+ * pwrdm_get_idle_state - Get the power state a pwrdm will enter during idle
+ * @pwrdm: powerdomain to check state for
+ *
+ * Checks if the powerdomain can enter idle or not, if yes, will return
+ * the programmed target state for the domain. Otherwise will indicate
+ * that the domain will stay on.
+ * Returns the power state the pwrdm will enter.
+ */
+static int pwrdm_get_idle_state(struct powerdomain *pwrdm)
+{
+ if (pwrdm_can_idle(pwrdm))
+ return pwrdm_read_next_pwrst(pwrdm);
+ return PWRDM_POWER_ON;
+}
+
+/**
* omap3_enter_idle - Programs OMAP3 to enter the specified state
* @dev: cpuidle device
* @state: The target state to be programmed
@@ -153,14 +170,94 @@ static int omap3_enter_idle_bm(struct cpuidle_device *dev,
struct cpuidle_state *state)
{
struct cpuidle_state *new_state = state;
-
- if ((state->flags & CPUIDLE_FLAG_CHECK_BM) && omap3_idle_bm_check()) {
- BUG_ON(!dev->safe_state);
- new_state = dev->safe_state;
+ u32 per_state = 0, saved_per_state = 0, cam_state, usb_state;
+ u32 iva2_state, sgx_state, dss_state, new_core_state;
+ struct omap3_processor_cx *cx;
+ int ret;
+
+ if (state->flags & CPUIDLE_FLAG_CHECK_BM) {
+ if (omap3_idle_bm_check()) {
+ BUG_ON(!dev->safe_state);
+ new_state = dev->safe_state;
+ goto select_state;
+ }
+ cx = cpuidle_get_statedata(state);
+ new_core_state = cx->core_state;
+
+ /* Check if CORE is active, if yes, fallback to inactive */
+ if (!pwrdm_can_idle(core_pd))
+ new_core_state = PWRDM_POWER_INACTIVE;
+
+ /*
+ * Prevent idle completely if CAM is active.
+ * CAM does not have wakeup capability in OMAP3.
+ */
+ cam_state = pwrdm_get_idle_state(cam_pd);
+ if (cam_state == PWRDM_POWER_ON) {
+ new_state = dev->safe_state;
+ goto select_state;
+ }
+
+ /*
+ * Check if PER can idle or not. If we are not likely
+ * to idle, deny PER off. This prevents unnecessary
+ * context save/restore.
+ */
+ saved_per_state = pwrdm_read_next_pwrst(per_pd);
+ if (pwrdm_can_idle(per_pd)) {
+ per_state = saved_per_state;
+ /*
+ * Prevent PER off if CORE is active as this
+ * would disable PER wakeups completely
+ */
+ if (per_state == PWRDM_POWER_OFF &&
+ new_core_state > PWRDM_POWER_RET)
+ per_state = PWRDM_POWER_RET;
+
+ } else if (saved_per_state == PWRDM_POWER_OFF)
+ per_state = PWRDM_POWER_RET;
+
+ /*
+ * If we are attempting CORE off, check if any other
+ * powerdomains are at retention or higher. CORE off causes
+ * chipwide reset which would reset these domains also.
+ */
+ if (new_core_state == PWRDM_POWER_OFF) {
+ dss_state = pwrdm_get_idle_state(dss_pd);
+ iva2_state = pwrdm_get_idle_state(iva2_pd);
+ sgx_state = pwrdm_get_idle_state(sgx_pd);
+ usb_state = pwrdm_get_idle_state(usb_pd);
+
+ if (cam_state > PWRDM_POWER_OFF ||
+ dss_state > PWRDM_POWER_OFF ||
+ iva2_state > PWRDM_POWER_OFF ||
+ per_state > PWRDM_POWER_OFF ||
+ sgx_state > PWRDM_POWER_OFF ||
+ usb_state > PWRDM_POWER_OFF)
+ new_core_state = PWRDM_POWER_RET;
+ }
+
+ /* Fallback to new target core state */
+ while (cx->core_state > new_core_state) {
+ state--;
+ cx = cpuidle_get_statedata(state);
+ }
+ new_state = state;
+
+ /* Are we changing PER target state? */
+ if (per_state != saved_per_state)
+ pwrdm_set_next_pwrst(per_pd, per_state);
}
+select_state:
dev->last_state = new_state;
- return omap3_enter_idle(dev, new_state);
+ ret = omap3_enter_idle(dev, new_state);
+
+ /* Restore potentially tampered PER state */
+ if (per_state != saved_per_state)
+ pwrdm_set_next_pwrst(per_pd, saved_per_state);
+
+ return ret;
}
DEFINE_PER_CPU(struct cpuidle_device, omap3_idle_dev);
@@ -224,7 +321,8 @@ void omap_init_power_states(void)
cpuidle_params_table[OMAP3_STATE_C2].threshold;
omap3_power_states[OMAP3_STATE_C2].mpu_state = PWRDM_POWER_INACTIVE;
omap3_power_states[OMAP3_STATE_C2].core_state = PWRDM_POWER_INACTIVE;
- 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 =
@@ -322,6 +420,12 @@ int __init omap3_idle_init(void)
mpu_pd = pwrdm_lookup("mpu_pwrdm");
core_pd = pwrdm_lookup("core_pwrdm");
+ per_pd = pwrdm_lookup("per_pwrdm");
+ iva2_pd = pwrdm_lookup("iva2_pwrdm");
+ sgx_pd = pwrdm_lookup("sgx_pwrdm");
+ usb_pd = pwrdm_lookup("usbhost_pwrdm");
+ cam_pd = pwrdm_lookup("cam_pwrdm");
+ dss_pd = pwrdm_lookup("dss_pwrdm");
omap_init_power_states();
cpuidle_register_driver(&omap3_idle_driver);
--
1.5.4.3
--
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