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OMAP3: PM: move device-specific special cases from PM core into CPUidle

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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>
This commit is contained in:
Kevin Hilman 2010-09-08 16:37:42 -07:00
parent 6cdee91257
commit e7410cf783
2 changed files with 56 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

58
arch/arm/mach-omap2/cpuidle34xx.c
View File

@ -60,7 +60,8 @@ 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;
struct powerdomain *cam_pd;
/*
* The latencies/thresholds for various C states have
@ -233,14 +234,62 @@ static int omap3_enter_idle_bm(struct cpuidle_device *dev,
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 @@ void omap_init_power_states(void)
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 @@ int __init omap3_idle_init(void)
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);

14
arch/arm/mach-omap2/pm34xx.c
View File

@ -346,7 +346,6 @@ void omap_sram_idle(void)
int core_next_state = PWRDM_POWER_ON;
int core_prev_state, per_prev_state;
u32 sdrc_pwr = 0;
int per_state_modified = 0;
if (!_omap_sram_idle)
return;
@ -391,19 +390,10 @@ void omap_sram_idle(void)
if (per_next_state < PWRDM_POWER_ON) {
omap_uart_prepare_idle(2);
omap2_gpio_prepare_for_idle(per_next_state);
if (per_next_state == PWRDM_POWER_OFF) {
if (core_next_state == PWRDM_POWER_ON) {
per_next_state = PWRDM_POWER_RET;
pwrdm_set_next_pwrst(per_pwrdm, per_next_state);
per_state_modified = 1;
} else
if (per_next_state == PWRDM_POWER_OFF)
omap3_per_save_context();
}
}
if (pwrdm_read_pwrst(cam_pwrdm) == PWRDM_POWER_ON)
omap2_clkdm_deny_idle(mpu_pwrdm->pwrdm_clkdms[0]);
/* CORE */
if (core_next_state < PWRDM_POWER_ON) {
omap_uart_prepare_idle(0);
@ -470,8 +460,6 @@ void omap_sram_idle(void)
if (per_prev_state == PWRDM_POWER_OFF)
omap3_per_restore_context();
omap_uart_resume_idle(2);
if (per_state_modified)
pwrdm_set_next_pwrst(per_pwrdm, PWRDM_POWER_OFF);
}
/* Disable IO-PAD and IO-CHAIN wakeup */