From: Rafael J. Wysocki Date: Sun, 27 Nov 2011 12:11:44 +0000 (+0100) Subject: PM / Domains: Introduce "save/restore state" device callbacks X-Git-Tag: firefly_0821_release~3680^2~3819^2~2^2~16 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=ecf00475f229fcf06362412ad2d15a3267e354a1;p=firefly-linux-kernel-4.4.55.git PM / Domains: Introduce "save/restore state" device callbacks The current PM domains code uses device drivers' .runtime_suspend() and .runtime_resume() callbacks as the "save device state" and "restore device state" operations, which may not be appropriate in general, because it forces drivers to assume that they always will be used with generic PM domains. However, in theory, the same hardware may be used in devices that don't belong to any PM domain, in which case it would be necessary to add "fake" PM domains to satisfy the above assumption. It also may be located in a PM domain that's not handled with the help of the generic code. To allow device drivers that may be used along with the generic PM domains code of more flexibility, introduce new device callbacks, .save_state() and .restore_state(), that can be supplied by the drivers in addition to their "standard" runtime PM callbacks. This will allow the drivers to be designed to work with generic PM domains as well as without them. For backwards compatibility, introduce default .save_state() and .restore_state() callback routines for PM domains that will execute a device driver's .runtime_suspend() and .runtime_resume() callbacks, respectively, for the given device if the driver doesn't provide its own implementations of .save_state() and .restore_state(). Signed-off-by: Rafael J. Wysocki --- diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 94afaa2686a6..3c9451b10427 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -56,6 +56,16 @@ static int genpd_start_dev(struct generic_pm_domain *genpd, struct device *dev) return GENPD_DEV_CALLBACK(genpd, int, start, dev); } +static int genpd_save_dev(struct generic_pm_domain *genpd, struct device *dev) +{ + return GENPD_DEV_CALLBACK(genpd, int, save_state, dev); +} + +static int genpd_restore_dev(struct generic_pm_domain *genpd, struct device *dev) +{ + return GENPD_DEV_CALLBACK(genpd, int, restore_state, dev); +} + static bool genpd_sd_counter_dec(struct generic_pm_domain *genpd) { bool ret = false; @@ -217,7 +227,6 @@ static int __pm_genpd_save_device(struct pm_domain_data *pdd, { struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd); struct device *dev = pdd->dev; - struct device_driver *drv = dev->driver; int ret = 0; if (gpd_data->need_restore) @@ -225,11 +234,9 @@ static int __pm_genpd_save_device(struct pm_domain_data *pdd, mutex_unlock(&genpd->lock); - if (drv && drv->pm && drv->pm->runtime_suspend) { - genpd_start_dev(genpd, dev); - ret = drv->pm->runtime_suspend(dev); - genpd_stop_dev(genpd, dev); - } + genpd_start_dev(genpd, dev); + ret = genpd_save_dev(genpd, dev); + genpd_stop_dev(genpd, dev); mutex_lock(&genpd->lock); @@ -250,18 +257,15 @@ static void __pm_genpd_restore_device(struct pm_domain_data *pdd, { struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd); struct device *dev = pdd->dev; - struct device_driver *drv = dev->driver; if (!gpd_data->need_restore) return; mutex_unlock(&genpd->lock); - if (drv && drv->pm && drv->pm->runtime_resume) { - genpd_start_dev(genpd, dev); - drv->pm->runtime_resume(dev); - genpd_stop_dev(genpd, dev); - } + genpd_start_dev(genpd, dev); + genpd_restore_dev(genpd, dev); + genpd_stop_dev(genpd, dev); mutex_lock(&genpd->lock); @@ -1357,6 +1361,44 @@ int pm_genpd_remove_callbacks(struct device *dev) } EXPORT_SYMBOL_GPL(pm_genpd_remove_callbacks); +/** + * pm_genpd_default_save_state - Default "save device state" for PM domians. + * @dev: Device to handle. + */ +static int pm_genpd_default_save_state(struct device *dev) +{ + int (*cb)(struct device *__dev); + struct device_driver *drv = dev->driver; + + cb = dev_gpd_data(dev)->ops.save_state; + if (cb) + return cb(dev); + + if (drv && drv->pm && drv->pm->runtime_suspend) + return drv->pm->runtime_suspend(dev); + + return 0; +} + +/** + * pm_genpd_default_restore_state - Default PM domians "restore device state". + * @dev: Device to handle. + */ +static int pm_genpd_default_restore_state(struct device *dev) +{ + int (*cb)(struct device *__dev); + struct device_driver *drv = dev->driver; + + cb = dev_gpd_data(dev)->ops.restore_state; + if (cb) + return cb(dev); + + if (drv && drv->pm && drv->pm->runtime_resume) + return drv->pm->runtime_resume(dev); + + return 0; +} + /** * pm_genpd_init - Initialize a generic I/O PM domain object. * @genpd: PM domain object to initialize. @@ -1400,6 +1442,8 @@ void pm_genpd_init(struct generic_pm_domain *genpd, genpd->domain.ops.restore_noirq = pm_genpd_restore_noirq; genpd->domain.ops.restore = pm_genpd_restore; genpd->domain.ops.complete = pm_genpd_complete; + genpd->dev_ops.save_state = pm_genpd_default_save_state; + genpd->dev_ops.restore_state = pm_genpd_default_restore_state; mutex_lock(&gpd_list_lock); list_add(&genpd->gpd_list_node, &gpd_list); mutex_unlock(&gpd_list_lock); diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index 8949d2d202ae..731080dad250 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -26,6 +26,8 @@ struct dev_power_governor { struct gpd_dev_ops { int (*start)(struct device *dev); int (*stop)(struct device *dev); + int (*save_state)(struct device *dev); + int (*restore_state)(struct device *dev); bool (*active_wakeup)(struct device *dev); };