diff options
Diffstat (limited to 'arch/arm/mach-omap2/powerdomain.c')
| -rw-r--r-- | arch/arm/mach-omap2/powerdomain.c | 161 |
1 files changed, 132 insertions, 29 deletions
diff --git a/arch/arm/mach-omap2/powerdomain.c b/arch/arm/mach-omap2/powerdomain.c index 97b3881dd60d..65c34645c8ed 100644 --- a/arch/arm/mach-omap2/powerdomain.c +++ b/arch/arm/mach-omap2/powerdomain.c @@ -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 * |