When a wake-up constraint is requested or removed the omap device layer dispatches the updated strongest constraint value. The power domains get the next power state programmed directly in the registers via pwrdm_wakeuplat_update_pwrst.
Note about PM QOS: the MPU and CORE power domains get the next power state via cpuidle, which get the strongest wake-up latency constraint by querying PM QOS. The usage of PM QOS is temporary, until a generic solution is in place. Tested on OMAP3 Beagleboard in RET/OFF using wake-up latency constraints on MPU, CORE and PER. Signed-off-by: Jean Pihet <[email protected]> --- arch/arm/mach-omap2/powerdomain.c | 100 +++++++++++++++++++++++++++++++++++++ arch/arm/mach-omap2/powerdomain.h | 24 ++++++++- 2 files changed, 122 insertions(+), 2 deletions(-) diff --git a/arch/arm/mach-omap2/powerdomain.c b/arch/arm/mach-omap2/powerdomain.c index eaed0df..54ac955 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 "cm2xxx_3xxx.h" #include "prcm44xx.h" #include "cm44xx.h" @@ -176,6 +177,105 @@ static int _pwrdm_post_transition_cb(struct powerdomain *pwrdm, void *unused) return 0; } +/* + * Test if the current powerdomain is MPU or CORE + * + * This function is only used by pwrdm_wakeuplat_update_pwrst + * which applies the MPU and CORE power domains constraints using PM QOS. + * + * This will disappear when all power domains will be controlled directly + * from the wake-up latency constraints framework + */ +static inline int is_pwrdm_mpu_or_core(struct powerdomain *pwrdm) +{ + if ((pwrdm == pwrdm_lookup("mpu_pwrdm")) || + (pwrdm == pwrdm_lookup("core_pwrdm"))) + return 1; + else + return 0; +} + +/** + * pwrdm_wakeuplat_update_pwrst - Update power domain power state if needed + * @pwrdm: struct powerdomain * to which requesting device belongs to. + * @min_latency: the allowed wake-up latency for the given power domain. A + * value of 0 means 'no constraint' on the pwrdm. + * + * Finds the power domain next power state that fulfills the constraint. + * Programs a new target state if it is different from current power state. + * + * Returns 0 upon success. + */ +int pwrdm_wakeuplat_update_pwrst(struct powerdomain *pwrdm, long min_latency) +{ + int ret = 0, new_state = 0; + + if (!pwrdm) { + WARN(1, "powerdomain: %s: invalid parameter(s)", __func__); + return -EINVAL; + } + + /* + * Apply constraints to MPU and CORE via the PM QOS API. + * Every power domain struct has a pm_qos_request_list field + */ + if (is_pwrdm_mpu_or_core(pwrdm)) { + if (pm_qos_request_active(&(pwrdm->pm_qos_request))) + pm_qos_remove_request(&(pwrdm->pm_qos_request)); + + if (min_latency > 0) + pm_qos_add_request(&(pwrdm->pm_qos_request), + PM_QOS_CPU_DMA_LATENCY, + min_latency); + + return 0; + } + + /* + * Apply constraints to pwrdm other than MPU and CORE by programming + * the pwrdm next power state. + */ + + /* Find power state with wakeup latency < minimum constraint */ + for (new_state = 0x0; new_state < PWRDM_MAX_PWRSTS; new_state++) { + if (min_latency == 0 || + pwrdm->wakeup_lat[new_state] <= min_latency) + break; + } + + switch (new_state) { + case PWRDM_FUNC_PWRST_OFF: + new_state = PWRDM_POWER_OFF; + break; + case PWRDM_FUNC_PWRST_OSWR: + pwrdm_set_logic_retst(pwrdm, PWRDM_POWER_OFF); + new_state = PWRDM_POWER_RET; + break; + case PWRDM_FUNC_PWRST_CSWR: + pwrdm_set_logic_retst(pwrdm, PWRDM_POWER_RET); + new_state = PWRDM_POWER_RET; + break; + case PWRDM_FUNC_PWRST_ON: + new_state = PWRDM_POWER_ON; + break; + default: + pr_warn("powerdomain: requested latency constraint not " + "supported %s set to ON state\n", pwrdm->name); + new_state = PWRDM_POWER_ON; + break; + } + + if (pwrdm_read_pwrst(pwrdm) != new_state) + ret = omap_set_pwrdm_state(pwrdm, new_state); + + pr_debug("powerdomain: %s pwrst: curr=%d, prev=%d next=%d " + "min_latency=%ld, set_state=%d\n", pwrdm->name, + pwrdm_read_pwrst(pwrdm), pwrdm_read_prev_pwrst(pwrdm), + pwrdm_read_next_pwrst(pwrdm), min_latency, new_state); + + return ret; +} + /* Public functions */ /** diff --git a/arch/arm/mach-omap2/powerdomain.h b/arch/arm/mach-omap2/powerdomain.h index 0b7a357..23b3408 100644 --- a/arch/arm/mach-omap2/powerdomain.h +++ b/arch/arm/mach-omap2/powerdomain.h @@ -19,7 +19,10 @@ #include <linux/types.h> #include <linux/list.h> - +#include <linux/plist.h> +#include <linux/mutex.h> +#include <linux/spinlock.h> +#include <linux/pm_qos_params.h> #include <linux/atomic.h> #include <plat/cpu.h> @@ -46,6 +49,15 @@ #define PWRSTS_OFF_RET_ON (PWRSTS_OFF_RET | (1 << PWRDM_POWER_ON)) +/* Powerdomain functional power states */ +#define PWRDM_FUNC_PWRST_OFF 0x0 +#define PWRDM_FUNC_PWRST_OSWR 0x1 +#define PWRDM_FUNC_PWRST_CSWR 0x2 +#define PWRDM_FUNC_PWRST_ON 0x3 + +#define PWRDM_MAX_FUNC_PWRSTS 4 + +#define UNSUP_STATE -1 /* Powerdomain flags */ #define PWRDM_HAS_HDWR_SAR (1 << 0) /* hardware save-and-restore support */ @@ -96,7 +108,11 @@ struct powerdomain; * @state_counter: * @timer: * @state_timer: - * + * @wakeup_lat: wakeup latencies (in us) for possible powerdomain power states + * Note about the wakeup latencies ordering: the values must be sorted + * in decremental order + * @pm_qos_request: PM QOS handle, only used to control the MPU and CORE power + * domains states; to be removed when a generic solution is in place. * @prcm_partition possible values are defined in mach-omap2/prcm44xx.h. */ struct powerdomain { @@ -121,6 +137,8 @@ struct powerdomain { s64 timer; s64 state_timer[PWRDM_MAX_PWRSTS]; #endif + const u32 wakeup_lat[PWRDM_MAX_FUNC_PWRSTS]; + struct pm_qos_request_list pm_qos_request; }; /** @@ -210,6 +228,8 @@ int pwrdm_clkdm_state_switch(struct clockdomain *clkdm); int pwrdm_pre_transition(void); int pwrdm_post_transition(void); int pwrdm_set_lowpwrstchange(struct powerdomain *pwrdm); + +int pwrdm_wakeuplat_update_pwrst(struct powerdomain *pwrdm, long min_latency); u32 pwrdm_get_context_loss_count(struct powerdomain *pwrdm); extern void omap2xxx_powerdomains_init(void); -- 1.7.2.3 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
