From 485995b09b76f20daaf39d11797f4b88cc5f6fa6 Mon Sep 17 00:00:00 2001 From: Russ Dill Date: Wed, 16 May 2018 20:47:00 +0530 Subject: ARM: OMAP2+: Add functions to save and restore powerdomain context The powerdomain control registers are stored in the WKUP powerdomain on AM33XX/AM43XX, which is lost on RTC-only suspend and also hibernate. This adds context save and restore functions for those registers. Sometimes the powerdomain state does not need to change, perhaps we only need to change memory retention states, so make sure the restored state is different from the current state before we wait for a transition. Signed-off-by: Keerthy Signed-off-by: Dave Gerlach Signed-off-by: Russ Dill Signed-off-by: Tony Lindgren --- arch/arm/mach-omap2/powerdomain.c | 60 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 60 insertions(+) (limited to 'arch/arm/mach-omap2/powerdomain.c') diff --git a/arch/arm/mach-omap2/powerdomain.c b/arch/arm/mach-omap2/powerdomain.c index 76eb6ec5f157..ee693f679ae8 100644 --- a/arch/arm/mach-omap2/powerdomain.c +++ b/arch/arm/mach-omap2/powerdomain.c @@ -1199,3 +1199,63 @@ bool pwrdm_can_ever_lose_context(struct powerdomain *pwrdm) return 0; } + +/** + * pwrdm_save_context - save powerdomain registers + * + * Register state is going to be lost due to a suspend or hibernate + * event. Save the powerdomain registers. + */ +static int pwrdm_save_context(struct powerdomain *pwrdm, void *unused) +{ + if (arch_pwrdm && arch_pwrdm->pwrdm_save_context) + arch_pwrdm->pwrdm_save_context(pwrdm); + return 0; +} + +/** + * pwrdm_save_context - restore powerdomain registers + * + * Restore powerdomain control registers after a suspend or resume + * event. + */ +static int pwrdm_restore_context(struct powerdomain *pwrdm, void *unused) +{ + if (arch_pwrdm && arch_pwrdm->pwrdm_restore_context) + arch_pwrdm->pwrdm_restore_context(pwrdm); + return 0; +} + +static int pwrdm_lost_power(struct powerdomain *pwrdm, void *unused) +{ + int state; + + /* + * Power has been lost across all powerdomains, increment the + * counter. + */ + + state = pwrdm_read_pwrst(pwrdm); + if (state != PWRDM_POWER_OFF) { + pwrdm->state_counter[state]++; + pwrdm->state_counter[PWRDM_POWER_OFF]++; + } + pwrdm->state = state; + + return 0; +} + +void pwrdms_save_context(void) +{ + pwrdm_for_each(pwrdm_save_context, NULL); +} + +void pwrdms_restore_context(void) +{ + pwrdm_for_each(pwrdm_restore_context, NULL); +} + +void pwrdms_lost_power(void) +{ + pwrdm_for_each(pwrdm_lost_power, NULL); +} -- cgit v1.2.3 From 4a6dfa480d7a202be9054536cd27cbec2333c9eb Mon Sep 17 00:00:00 2001 From: Keerthy Date: Wed, 16 May 2018 20:47:01 +0530 Subject: ARM: OMAP2+: powerdomain: Introduce cpu_pm notifiers for context save/restore Inroduce cpu_pm notifiers for context save/restore. This is needed for am43xx family during rtc only mode with ddr in self-refresh. Signed-off-by: Keerthy Signed-off-by: Tony Lindgren --- arch/arm/mach-omap2/powerdomain.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'arch/arm/mach-omap2/powerdomain.c') diff --git a/arch/arm/mach-omap2/powerdomain.c b/arch/arm/mach-omap2/powerdomain.c index ee693f679ae8..27fdef624e97 100644 --- a/arch/arm/mach-omap2/powerdomain.c +++ b/arch/arm/mach-omap2/powerdomain.c @@ -14,6 +14,7 @@ */ #undef DEBUG +#include #include #include #include @@ -39,6 +40,9 @@ #define PWRDM_TRACE_STATES_FLAG (1<<31) +void pwrdms_save_context(void); +void pwrdms_restore_context(void); + enum { PWRDM_STATE_NOW = 0, PWRDM_STATE_PREV, @@ -333,6 +337,22 @@ int pwrdm_register_pwrdms(struct powerdomain **ps) return 0; } +static int cpu_notifier(struct notifier_block *nb, unsigned long cmd, void *v) +{ + switch (cmd) { + case CPU_CLUSTER_PM_ENTER: + if (enable_off_mode) + pwrdms_save_context(); + break; + case CPU_CLUSTER_PM_EXIT: + if (enable_off_mode) + pwrdms_restore_context(); + break; + } + + return NOTIFY_OK; +} + /** * pwrdm_complete_init - set up the powerdomain layer * @@ -347,6 +367,7 @@ int pwrdm_register_pwrdms(struct powerdomain **ps) int pwrdm_complete_init(void) { struct powerdomain *temp_p; + static struct notifier_block nb; if (list_empty(&pwrdm_list)) return -EACCES; @@ -354,6 +375,12 @@ int pwrdm_complete_init(void) list_for_each_entry(temp_p, &pwrdm_list, node) pwrdm_set_next_pwrst(temp_p, PWRDM_POWER_ON); + /* Only AM43XX can lose pwrdm context during rtc-ddr suspend */ + if (soc_is_am43xx()) { + nb.notifier_call = cpu_notifier; + cpu_pm_register_notifier(&nb); + } + return 0; } -- cgit v1.2.3