diff options
Diffstat (limited to 'arch/arm/mach-omap2/powerdomain.c')
| -rw-r--r-- | arch/arm/mach-omap2/powerdomain.c | 232 |
1 files changed, 180 insertions, 52 deletions
diff --git a/arch/arm/mach-omap2/powerdomain.c b/arch/arm/mach-omap2/powerdomain.c index dea62a9aad0..8e61d80bf6b 100644 --- a/arch/arm/mach-omap2/powerdomain.c +++ b/arch/arm/mach-omap2/powerdomain.c @@ -19,6 +19,7 @@ #include <linux/list.h> #include <linux/errno.h> #include <linux/string.h> +#include <linux/spinlock.h> #include <trace/events/power.h> #include "cm2xxx_3xxx.h" @@ -42,6 +43,16 @@ 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); @@ -101,6 +112,7 @@ static int _pwrdm_register(struct powerdomain *pwrdm) pwrdm->voltdm.ptr = voltdm; INIT_LIST_HEAD(&pwrdm->voltdm_node); voltdm_add_pwrdm(voltdm, pwrdm); + spin_lock_init(&pwrdm->_lock); list_add(&pwrdm->node, &pwrdm_list); @@ -112,7 +124,7 @@ static int _pwrdm_register(struct powerdomain *pwrdm) for (i = 0; i < pwrdm->banks; i++) pwrdm->ret_mem_off_counter[i] = 0; - pwrdm_wait_transition(pwrdm); + arch_pwrdm->pwrdm_wait_transition(pwrdm); pwrdm->state = pwrdm_read_pwrst(pwrdm); pwrdm->state_counter[pwrdm->state] = 1; @@ -143,7 +155,7 @@ static void _update_logic_membank_counters(struct powerdomain *pwrdm) static int _pwrdm_state_switch(struct powerdomain *pwrdm, int flag) { - int prev, state, trace_state = 0; + int prev, next, state, trace_state = 0; if (pwrdm == NULL) return -EINVAL; @@ -164,9 +176,10 @@ static int _pwrdm_state_switch(struct powerdomain *pwrdm, int flag) * If the power domain did not hit the desired state, * generate a trace event with both the desired and hit states */ - if (state != prev) { + next = pwrdm_read_next_pwrst(pwrdm); + if (next != prev) { trace_state = (PWRDM_TRACE_STATES_FLAG | - ((state & OMAP_POWERSTATE_MASK) << 8) | + ((next & OMAP_POWERSTATE_MASK) << 8) | ((prev & OMAP_POWERSTATE_MASK) << 0)); trace_power_domain_target(pwrdm->name, trace_state, smp_processor_id()); @@ -199,6 +212,80 @@ 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_nolock(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_nolock(pwrdm->pwrdm_clkdms[0]); + else + clkdm_sleep_nolock(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_nolock(pwrdm); + break; + } +} + /* Public functions */ /** @@ -275,6 +362,30 @@ int pwrdm_complete_init(void) } /** + * pwrdm_lock - acquire a Linux spinlock on a powerdomain + * @pwrdm: struct powerdomain * to lock + * + * Acquire the powerdomain spinlock on @pwrdm. No return value. + */ +void pwrdm_lock(struct powerdomain *pwrdm) + __acquires(&pwrdm->_lock) +{ + spin_lock_irqsave(&pwrdm->_lock, pwrdm->_lock_flags); +} + +/** + * pwrdm_unlock - release a Linux spinlock on a powerdomain + * @pwrdm: struct powerdomain * to unlock + * + * Release the powerdomain spinlock on @pwrdm. No return value. + */ +void pwrdm_unlock(struct powerdomain *pwrdm) + __releases(&pwrdm->_lock) +{ + spin_unlock_irqrestore(&pwrdm->_lock, pwrdm->_lock_flags); +} + +/** * pwrdm_lookup - look up a powerdomain by name, return a pointer * @name: name of powerdomain * @@ -920,65 +1031,27 @@ 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; -} - -/** - * pwrdm_wait_transition - wait for powerdomain power transition to finish - * @pwrdm: struct powerdomain * to wait for - * - * If the powerdomain @pwrdm is in the process of a state transition, - * spin until it completes the power transition, or until an iteration - * bailout value is reached. Returns -EINVAL if the powerdomain - * pointer is null, -EAGAIN if the bailout value was reached, or - * returns 0 upon success. - */ -int pwrdm_wait_transition(struct powerdomain *pwrdm) +int pwrdm_state_switch_nolock(struct powerdomain *pwrdm) { - int ret = -EINVAL; + int ret; - if (!pwrdm) + if (!pwrdm || !arch_pwrdm) return -EINVAL; - if (arch_pwrdm && arch_pwrdm->pwrdm_wait_transition) - ret = arch_pwrdm->pwrdm_wait_transition(pwrdm); + ret = arch_pwrdm->pwrdm_wait_transition(pwrdm); + if (!ret) + ret = _pwrdm_state_switch(pwrdm, PWRDM_STATE_NOW); return ret; } -int pwrdm_state_switch(struct powerdomain *pwrdm) +int __deprecated pwrdm_state_switch(struct powerdomain *pwrdm) { int ret; - ret = pwrdm_wait_transition(pwrdm); - if (!ret) - ret = _pwrdm_state_switch(pwrdm, PWRDM_STATE_NOW); + pwrdm_lock(pwrdm); + ret = pwrdm_state_switch_nolock(pwrdm); + pwrdm_unlock(pwrdm); return ret; } @@ -1004,6 +1077,61 @@ 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--; + } + + pwrdm_lock(pwrdm); + + curr_pwrst = pwrdm_read_pwrst(pwrdm); + next_pwrst = pwrdm_read_next_pwrst(pwrdm); + if (curr_pwrst == pwrst && next_pwrst == pwrst) + goto osps_out; + + sleep_switch = _pwrdm_save_clkdm_state_and_activate(pwrdm, curr_pwrst, + pwrst, &hwsup); + if (sleep_switch == ERROR_SWITCH) { + ret = -EINVAL; + goto osps_out; + } + + 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); + +osps_out: + pwrdm_unlock(pwrdm); + + return ret; +} + +/** * pwrdm_get_context_loss_count - get powerdomain's context loss count * @pwrdm: struct powerdomain * to wait for * |