@@ -108,10 +108,6 @@ static void __init omap2_init_processor_devices(void)
}
}
-/* Types of sleep_switch used in omap_set_pwrdm_state */
-#define FORCEWAKEUP_SWITCH 0
-#define LOWPOWERSTATE_SWITCH 1
-
int __init omap_pm_clkdms_setup(struct clockdomain *clkdm, void *unused)
{
if ((clkdm->flags & CLKDM_CAN_ENABLE_AUTO) &&
@@ -124,63 +120,6 @@ int __init omap_pm_clkdms_setup(struct clockdomain *clkdm, void *unused)
}
/*
- * This sets pwrdm state (other than mpu & core. Currently only ON &
- * RET are supported.
- */
-int omap_set_pwrdm_state(struct powerdomain *pwrdm, u32 pwrst)
-{
- u8 curr_pwrst, next_pwrst;
- int sleep_switch = -1, ret = 0, hwsup = 0;
-
- if (!pwrdm || IS_ERR(pwrdm))
- return -EINVAL;
-
- while (!(pwrdm->pwrsts & (1 << pwrst))) {
- if (pwrst == PWRDM_POWER_OFF)
- return ret;
- pwrst--;
- }
-
- next_pwrst = pwrdm_read_next_pwrst(pwrdm);
- if (next_pwrst == pwrst)
- return ret;
-
- curr_pwrst = pwrdm_read_pwrst(pwrdm);
- if (curr_pwrst < PWRDM_POWER_ON) {
- if ((curr_pwrst > pwrst) &&
- (pwrdm->flags & PWRDM_HAS_LOWPOWERSTATECHANGE)) {
- sleep_switch = LOWPOWERSTATE_SWITCH;
- } else {
- hwsup = clkdm_in_hwsup(pwrdm->pwrdm_clkdms[0]);
- clkdm_wakeup(pwrdm->pwrdm_clkdms[0]);
- sleep_switch = FORCEWAKEUP_SWITCH;
- }
- }
-
- ret = pwrdm_set_next_pwrst(pwrdm, pwrst);
- if (ret)
- pr_err("%s: unable to set power state of powerdomain: %s\n",
- __func__, pwrdm->name);
-
- switch (sleep_switch) {
- case FORCEWAKEUP_SWITCH:
- if (hwsup)
- clkdm_allow_idle(pwrdm->pwrdm_clkdms[0]);
- else
- clkdm_sleep(pwrdm->pwrdm_clkdms[0]);
- break;
- case LOWPOWERSTATE_SWITCH:
- pwrdm_set_lowpwrstchange(pwrdm);
- pwrdm_state_switch(pwrdm);
- break;
- }
-
- return ret;
-}
-
-
-
-/*
* This API is to be called during init to set the various voltage
* domains to the voltage as per the opp table. Typically we boot up
* at the nominal voltage. So this function finds out the rate of
@@ -33,7 +33,6 @@ static inline int omap4_idle_init(void)
extern void *omap3_secure_ram_storage;
extern void omap3_pm_off_mode_enable(int);
extern void omap_sram_idle(void);
-extern int omap_set_pwrdm_state(struct powerdomain *pwrdm, u32 state);
extern int omap_pm_clkdms_setup(struct clockdomain *clkdm, void *unused);
extern int (*omap_pm_suspend)(void);
@@ -42,6 +42,16 @@ enum {
PWRDM_STATE_PREV,
};
+/*
+ * Types of sleep_switch used internally in omap_set_pwrdm_state()
+ * and its associated static functions
+ *
+ * XXX Better documentation is needed here
+ */
+#define ALREADYACTIVE_SWITCH 0
+#define FORCEWAKEUP_SWITCH 1
+#define LOWPOWERSTATE_SWITCH 2
+#define ERROR_SWITCH 3
/* pwrdm_list contains all registered struct powerdomains */
static LIST_HEAD(pwrdm_list);
@@ -200,6 +210,80 @@ static int _pwrdm_post_transition_cb(struct powerdomain *pwrdm, void *unused)
return 0;
}
+/**
+ * _pwrdm_save_clkdm_state_and_activate - prepare for power state change
+ * @pwrdm: struct powerdomain * to operate on
+ * @curr_pwrst: current power state of @pwrdm
+ * @pwrst: power state to switch to
+ * @hwsup: ptr to a bool to return whether the clkdm is hardware-supervised
+ *
+ * Determine whether the powerdomain needs to be turned on before
+ * attempting to switch power states. Called by
+ * omap_set_pwrdm_state(). NOTE that if the powerdomain contains
+ * multiple clockdomains, this code assumes that the first clockdomain
+ * supports software-supervised wakeup mode - potentially a problem.
+ * Returns the power state switch mode currently in use (see the
+ * "Types of sleep_switch" comment above).
+ */
+static u8 _pwrdm_save_clkdm_state_and_activate(struct powerdomain *pwrdm,
+ u8 curr_pwrst, u8 pwrst,
+ bool *hwsup)
+{
+ u8 sleep_switch;
+
+ if (curr_pwrst < 0) {
+ WARN_ON(1);
+ sleep_switch = ERROR_SWITCH;
+ } else if (curr_pwrst < PWRDM_POWER_ON) {
+ if (curr_pwrst > pwrst &&
+ pwrdm->flags & PWRDM_HAS_LOWPOWERSTATECHANGE &&
+ arch_pwrdm->pwrdm_set_lowpwrstchange) {
+ sleep_switch = LOWPOWERSTATE_SWITCH;
+ } else {
+ *hwsup = clkdm_in_hwsup(pwrdm->pwrdm_clkdms[0]);
+ clkdm_wakeup(pwrdm->pwrdm_clkdms[0]);
+ sleep_switch = FORCEWAKEUP_SWITCH;
+ }
+ } else {
+ sleep_switch = ALREADYACTIVE_SWITCH;
+ }
+
+ return sleep_switch;
+}
+
+/**
+ * _pwrdm_restore_clkdm_state - restore the clkdm hwsup state after pwrst change
+ * @pwrdm: struct powerdomain * to operate on
+ * @sleep_switch: return value from _pwrdm_save_clkdm_state_and_activate()
+ * @hwsup: should @pwrdm's first clockdomain be set to hardware-supervised mode?
+ *
+ * Restore the clockdomain state perturbed by
+ * _pwrdm_save_clkdm_state_and_activate(), and call the power state
+ * bookkeeping code. Called by omap_set_pwrdm_state(). NOTE that if
+ * the powerdomain contains multiple clockdomains, this assumes that
+ * the first associated clockdomain supports either
+ * hardware-supervised idle control in the register, or
+ * software-supervised sleep. No return value.
+ */
+static void _pwrdm_restore_clkdm_state(struct powerdomain *pwrdm,
+ u8 sleep_switch, bool hwsup)
+{
+ switch (sleep_switch) {
+ case FORCEWAKEUP_SWITCH:
+ if (hwsup)
+ clkdm_allow_idle(pwrdm->pwrdm_clkdms[0]);
+ else
+ clkdm_sleep(pwrdm->pwrdm_clkdms[0]);
+ break;
+ case LOWPOWERSTATE_SWITCH:
+ if (pwrdm->flags & PWRDM_HAS_LOWPOWERSTATECHANGE &&
+ arch_pwrdm->pwrdm_set_lowpwrstchange)
+ arch_pwrdm->pwrdm_set_lowpwrstchange(pwrdm);
+ pwrdm_state_switch(pwrdm);
+ break;
+ }
+}
+
/* Public functions */
/**
@@ -921,35 +1005,6 @@ bool pwrdm_has_hdwr_sar(struct powerdomain *pwrdm)
return (pwrdm && pwrdm->flags & PWRDM_HAS_HDWR_SAR) ? 1 : 0;
}
-/**
- * pwrdm_set_lowpwrstchange - Request a low power state change
- * @pwrdm: struct powerdomain *
- *
- * Allows a powerdomain to transtion to a lower power sleep state
- * from an existing sleep state without waking up the powerdomain.
- * Returns -EINVAL if the powerdomain pointer is null or if the
- * powerdomain does not support LOWPOWERSTATECHANGE, or returns 0
- * upon success.
- */
-int pwrdm_set_lowpwrstchange(struct powerdomain *pwrdm)
-{
- int ret = -EINVAL;
-
- if (!pwrdm)
- return -EINVAL;
-
- if (!(pwrdm->flags & PWRDM_HAS_LOWPOWERSTATECHANGE))
- return -EINVAL;
-
- pr_debug("powerdomain: %s: setting LOWPOWERSTATECHANGE bit\n",
- pwrdm->name);
-
- if (arch_pwrdm && arch_pwrdm->pwrdm_set_lowpwrstchange)
- ret = arch_pwrdm->pwrdm_set_lowpwrstchange(pwrdm);
-
- return ret;
-}
-
int pwrdm_state_switch(struct powerdomain *pwrdm)
{
int ret;
@@ -985,6 +1040,54 @@ int pwrdm_post_transition(struct powerdomain *pwrdm)
}
/**
+ * omap_set_pwrdm_state - change a powerdomain's current power state
+ * @pwrdm: struct powerdomain * to change the power state of
+ * @pwrst: power state to change to
+ *
+ * Change the current hardware power state of the powerdomain
+ * represented by @pwrdm to the power state represented by @pwrst.
+ * Returns -EINVAL if @pwrdm is null or invalid or if the
+ * powerdomain's current power state could not be read, or returns 0
+ * upon success or if @pwrdm does not support @pwrst or any
+ * lower-power state. XXX Should not return 0 if the @pwrdm does not
+ * support @pwrst or any lower-power state: this should be an error.
+ */
+int omap_set_pwrdm_state(struct powerdomain *pwrdm, u8 pwrst)
+{
+ u8 curr_pwrst, next_pwrst, sleep_switch;
+ int ret = 0;
+ bool hwsup = false;
+
+ if (!pwrdm || IS_ERR(pwrdm))
+ return -EINVAL;
+
+ while (!(pwrdm->pwrsts & (1 << pwrst))) {
+ if (pwrst == PWRDM_POWER_OFF)
+ return ret;
+ pwrst--;
+ }
+
+ curr_pwrst = pwrdm_read_pwrst(pwrdm);
+ next_pwrst = pwrdm_read_next_pwrst(pwrdm);
+ if (curr_pwrst == pwrst && next_pwrst == pwrst)
+ return ret;
+
+ sleep_switch = _pwrdm_save_clkdm_state_and_activate(pwrdm, curr_pwrst,
+ pwrst, &hwsup);
+ if (sleep_switch == ERROR_SWITCH)
+ return -EINVAL;
+
+ ret = pwrdm_set_next_pwrst(pwrdm, pwrst);
+ if (ret)
+ pr_err("%s: unable to set power state of powerdomain: %s\n",
+ __func__, pwrdm->name);
+
+ _pwrdm_restore_clkdm_state(pwrdm, sleep_switch, hwsup);
+
+ return ret;
+}
+
+/**
* pwrdm_get_context_loss_count - get powerdomain's context loss count
* @pwrdm: struct powerdomain * to wait for
*
@@ -162,6 +162,16 @@ struct powerdomain {
* @pwrdm_disable_hdwr_sar: Disable Hardware Save-Restore feature for a pd
* @pwrdm_set_lowpwrstchange: Enable pd transitions from a shallow to deep sleep
* @pwrdm_wait_transition: Wait for a pd state transition to complete
+ *
+ * Regarding @pwrdm_set_lowpwrstchange: On the OMAP2 and 3-family
+ * chips, a powerdomain's power state is not allowed to directly
+ * transition from one low-power state (e.g., CSWR) to another
+ * low-power state (e.g., OFF) without first waking up the
+ * powerdomain. This wastes energy. So OMAP4 chips support the
+ * ability to transition a powerdomain power state directly from one
+ * low-power state to another. The function pointed to by
+ * @pwrdm_set_lowpwrstchange is intended to configure the OMAP4
+ * hardware powerdomain state machine to enable this feature.
*/
struct pwrdm_ops {
int (*pwrdm_set_next_pwrst)(struct powerdomain *pwrdm, u8 pwrst);
@@ -228,10 +238,11 @@ bool pwrdm_has_hdwr_sar(struct powerdomain *pwrdm);
int pwrdm_state_switch(struct powerdomain *pwrdm);
int pwrdm_pre_transition(struct powerdomain *pwrdm);
int pwrdm_post_transition(struct powerdomain *pwrdm);
-int pwrdm_set_lowpwrstchange(struct powerdomain *pwrdm);
int pwrdm_get_context_loss_count(struct powerdomain *pwrdm);
bool pwrdm_can_ever_lose_context(struct powerdomain *pwrdm);
+extern int omap_set_pwrdm_state(struct powerdomain *pwrdm, u8 state);
+
extern void omap242x_powerdomains_init(void);
extern void omap243x_powerdomains_init(void);
extern void omap3xxx_powerdomains_init(void);