diff options
| -rw-r--r-- | Documentation/devicetree/bindings/power/power_domain.txt | 49 | ||||
| -rw-r--r-- | drivers/base/power/domain.c | 289 | ||||
| -rw-r--r-- | include/linux/pm_domain.h | 52 | ||||
| -rw-r--r-- | kernel/power/Kconfig | 4 |
4 files changed, 394 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/power/power_domain.txt b/Documentation/devicetree/bindings/power/power_domain.txt new file mode 100644 index 000000000000..98c16672ab5f --- /dev/null +++ b/Documentation/devicetree/bindings/power/power_domain.txt @@ -0,0 +1,49 @@ +* Generic PM domains + +System on chip designs are often divided into multiple PM domains that can be +used for power gating of selected IP blocks for power saving by reduced leakage +current. + +This device tree binding can be used to bind PM domain consumer devices with +their PM domains provided by PM domain providers. A PM domain provider can be +represented by any node in the device tree and can provide one or more PM +domains. A consumer node can refer to the provider by a phandle and a set of +phandle arguments (so called PM domain specifiers) of length specified by the +#power-domain-cells property in the PM domain provider node. + +==PM domain providers== + +Required properties: + - #power-domain-cells : Number of cells in a PM domain specifier; + Typically 0 for nodes representing a single PM domain and 1 for nodes + providing multiple PM domains (e.g. power controllers), but can be any value + as specified by device tree binding documentation of particular provider. + +Example: + + power: power-controller@12340000 { + compatible = "foo,power-controller"; + reg = <0x12340000 0x1000>; + #power-domain-cells = <1>; + }; + +The node above defines a power controller that is a PM domain provider and +expects one cell as its phandle argument. + +==PM domain consumers== + +Required properties: + - power-domains : A phandle and PM domain specifier as defined by bindings of + the power controller specified by phandle. + +Example: + + leaky-device@12350000 { + compatible = "foo,i-leak-current"; + reg = <0x12350000 0x1000>; + power-domains = <&power 0>; + }; + +The node above defines a typical PM domain consumer device, which is located +inside a PM domain with index 0 of a power controller represented by a node +with the label "power". diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index e6a11ca3ce26..a3d41a883d83 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -8,6 +8,7 @@ #include <linux/kernel.h> #include <linux/io.h> +#include <linux/platform_device.h> #include <linux/pm_runtime.h> #include <linux/pm_domain.h> #include <linux/pm_qos.h> @@ -1933,3 +1934,291 @@ void pm_genpd_init(struct generic_pm_domain *genpd, list_add(&genpd->gpd_list_node, &gpd_list); mutex_unlock(&gpd_list_lock); } + +#ifdef CONFIG_PM_GENERIC_DOMAINS_OF +/* + * Device Tree based PM domain providers. + * + * The code below implements generic device tree based PM domain providers that + * bind device tree nodes with generic PM domains registered in the system. + * + * Any driver that registers generic PM domains and needs to support binding of + * devices to these domains is supposed to register a PM domain provider, which + * maps a PM domain specifier retrieved from the device tree to a PM domain. + * + * Two simple mapping functions have been provided for convenience: + * - __of_genpd_xlate_simple() for 1:1 device tree node to PM domain mapping. + * - __of_genpd_xlate_onecell() for mapping of multiple PM domains per node by + * index. + */ + +/** + * struct of_genpd_provider - PM domain provider registration structure + * @link: Entry in global list of PM domain providers + * @node: Pointer to device tree node of PM domain provider + * @xlate: Provider-specific xlate callback mapping a set of specifier cells + * into a PM domain. + * @data: context pointer to be passed into @xlate callback + */ +struct of_genpd_provider { + struct list_head link; + struct device_node *node; + genpd_xlate_t xlate; + void *data; +}; + +/* List of registered PM domain providers. */ +static LIST_HEAD(of_genpd_providers); +/* Mutex to protect the list above. */ +static DEFINE_MUTEX(of_genpd_mutex); + +/** + * __of_genpd_xlate_simple() - Xlate function for direct node-domain mapping + * @genpdspec: OF phandle args to map into a PM domain + * @data: xlate function private data - pointer to struct generic_pm_domain + * + * This is a generic xlate function that can be used to model PM domains that + * have their own device tree nodes. The private data of xlate function needs + * to be a valid pointer to struct generic_pm_domain. + */ +struct generic_pm_domain *__of_genpd_xlate_simple( + struct of_phandle_args *genpdspec, + void *data) +{ + if (genpdspec->args_count != 0) + return ERR_PTR(-EINVAL); + return data; +} +EXPORT_SYMBOL_GPL(__of_genpd_xlate_simple); + +/** + * __of_genpd_xlate_onecell() - Xlate function using a single index. + * @genpdspec: OF phandle args to map into a PM domain + * @data: xlate function private data - pointer to struct genpd_onecell_data + * + * This is a generic xlate function that can be used to model simple PM domain + * controllers that have one device tree node and provide multiple PM domains. + * A single cell is used as an index into an array of PM domains specified in + * the genpd_onecell_data struct when registering the provider. + */ +struct generic_pm_domain *__of_genpd_xlate_onecell( + struct of_phandle_args *genpdspec, + void *data) +{ + struct genpd_onecell_data *genpd_data = data; + unsigned int idx = genpdspec->args[0]; + + if (genpdspec->args_count != 1) + return ERR_PTR(-EINVAL); + + if (idx >= genpd_data->num_domains) { + pr_err("%s: invalid domain index %u\n", __func__, idx); + return ERR_PTR(-EINVAL); + } + + if (!genpd_data->domains[idx]) + return ERR_PTR(-ENOENT); + + return genpd_data->domains[idx]; +} +EXPORT_SYMBOL_GPL(__of_genpd_xlate_onecell); + +/** + * __of_genpd_add_provider() - Register a PM domain provider for a node + * @np: Device node pointer associated with the PM domain provider. + * @xlate: Callback for decoding PM domain from phandle arguments. + * @data: Context pointer for @xlate callback. + */ +int __of_genpd_add_provider(struct device_node *np, genpd_xlate_t xlate, + void *data) +{ + struct of_genpd_provider *cp; + + cp = kzalloc(sizeof(*cp), GFP_KERNEL); + if (!cp) + return -ENOMEM; + + cp->node = of_node_get(np); + cp->data = data; + cp->xlate = xlate; + + mutex_lock(&of_genpd_mutex); + list_add(&cp->link, &of_genpd_providers); + mutex_unlock(&of_genpd_mutex); + pr_debug("Added domain provider from %s\n", np->full_name); + + return 0; +} +EXPORT_SYMBOL_GPL(__of_genpd_add_provider); + +/** + * of_genpd_del_provider() - Remove a previously registered PM domain provider + * @np: Device node pointer associated with the PM domain provider + */ +void of_genpd_del_provider(struct device_node *np) +{ + struct of_genpd_provider *cp; + + mutex_lock(&of_genpd_mutex); + list_for_each_entry(cp, &of_genpd_providers, link) { + if (cp->node == np) { + list_del(&cp->link); + of_node_put(cp->node); + kfree(cp); + break; + } + } + mutex_unlock(&of_genpd_mutex); +} +EXPORT_SYMBOL_GPL(of_genpd_del_provider); + +/** + * of_genpd_get_from_provider() - Look-up PM domain + * @genpdspec: OF phandle args to use for look-up + * + * Looks for a PM domain provider under the node specified by @genpdspec and if + * found, uses xlate function of the provider to map phandle args to a PM + * domain. + * + * Returns a valid pointer to struct generic_pm_domain on success or ERR_PTR() + * on failure. + */ +static struct generic_pm_domain *of_genpd_get_from_provider( + struct of_phandle_args *genpdspec) +{ + struct generic_pm_domain *genpd = ERR_PTR(-ENOENT); + struct of_genpd_provider *provider; + + mutex_lock(&of_genpd_mutex); + + /* Check if we have such a provider in our array */ + list_for_each_entry(provider, &of_genpd_providers, link) { + if (provider->node == genpdspec->np) + genpd = provider->xlate(genpdspec, provider->data); + if (!IS_ERR(genpd)) + break; + } + + mutex_unlock(&of_genpd_mutex); + + return genpd; +} + +/** + * genpd_dev_pm_detach - Detach a device from its PM domain. + * @dev: Device to attach. + * @power_off: Currently not used + * + * Try to locate a corresponding generic PM domain, which the device was + * attached to previously. If such is found, the device is detached from it. + */ +static void genpd_dev_pm_detach(struct device *dev, bool power_off) +{ + struct generic_pm_domain *pd = NULL, *gpd; + int ret = 0; + + if (!dev->pm_domain) + return; + + mutex_lock(&gpd_list_lock); + list_for_each_entry(gpd, &gpd_list, gpd_list_node) { + if (&gpd->domain == dev->pm_domain) { + pd = gpd; + break; + } + } + mutex_unlock(&gpd_list_lock); + + if (!pd) + return; + + dev_dbg(dev, "removing from PM domain %s\n", pd->name); + + while (1) { + ret = pm_genpd_remove_device(pd, dev); + if (ret != -EAGAIN) + break; + cond_resched(); + } + + if (ret < 0) { + dev_err(dev, "failed to remove from PM domain %s: %d", + pd->name, ret); + return; + } + + /* Check if PM domain can be powered off after removing this device. */ + genpd_queue_power_off_work(pd); +} + +/** + * genpd_dev_pm_attach - Attach a device to its PM domain using DT. + * @dev: Device to attach. + * + * Parse device's OF node to find a PM domain specifier. If such is found, + * attaches the device to retrieved pm_domain ops. + * + * Both generic and legacy Samsung-specific DT bindings are supported to keep + * backwards compatibility with existing DTBs. + * + * Returns 0 on successfully attached PM domain or negative error code. + */ +int genpd_dev_pm_attach(struct device *dev) +{ + struct of_phandle_args pd_args; + struct generic_pm_domain *pd; + int ret; + + if (!dev->of_node) + return -ENODEV; + + if (dev->pm_domain) + return -EEXIST; + + ret = of_parse_phandle_with_args(dev->of_node, "power-domains", + "#power-domain-cells", 0, &pd_args); + if (ret < 0) { + if (ret != -ENOENT) + return ret; + + /* + * Try legacy Samsung-specific bindings + * (for backwards compatibility of DT ABI) + */ + pd_args.args_count = 0; + pd_args.np = of_parse_phandle(dev->of_node, + "samsung,power-domain", 0); + if (!pd_args.np) + return -ENOENT; + } + + pd = of_genpd_get_from_provider(&pd_args); + if (IS_ERR(pd)) { + dev_dbg(dev, "%s() failed to find PM domain: %ld\n", + __func__, PTR_ERR(pd)); + of_node_put(dev->of_node); + return PTR_ERR(pd); + } + + dev_dbg(dev, "adding to PM domain %s\n", pd->name); + + while (1) { + ret = pm_genpd_add_device(pd, dev); + if (ret != -EAGAIN) + break; + cond_resched(); + } + + if (ret < 0) { + dev_err(dev, "failed to add to PM domain %s: %d", + pd->name, ret); + of_node_put(dev->of_node); + return ret; + } + + dev->pm_domain->detach = genpd_dev_pm_detach; + + return 0; +} +EXPORT_SYMBOL_GPL(genpd_dev_pm_attach); +#endif diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index aa03586c94a2..292079d8da6b 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -264,4 +264,56 @@ static inline void pm_genpd_syscore_poweroff(struct device *dev) {} static inline void pm_genpd_syscore_poweron(struct device *dev) {} #endif +/* OF PM domain providers */ +struct of_device_id; + +struct genpd_onecell_data { + struct generic_pm_domain **domains; + unsigned int num_domains; +}; + +typedef struct generic_pm_domain *(*genpd_xlate_t)(struct of_phandle_args *args, + void *data); + +#ifdef CONFIG_PM_GENERIC_DOMAINS_OF +int __of_genpd_add_provider(struct device_node *np, genpd_xlate_t xlate, + void *data); +void of_genpd_del_provider(struct device_node *np); + +struct generic_pm_domain *__of_genpd_xlate_simple( + struct of_phandle_args *genpdspec, + void *data); +struct generic_pm_domain *__of_genpd_xlate_onecell( + struct of_phandle_args *genpdspec, + void *data); + +int genpd_dev_pm_attach(struct device *dev); +#else /* !CONFIG_PM_GENERIC_DOMAINS_OF */ +static inline int __of_genpd_add_provider(struct device_node *np, + genpd_xlate_t xlate, void *data) +{ + return 0; +} +static inline void of_genpd_del_provider(struct device_node *np) {} + +#define __of_genpd_xlate_simple NULL +#define __of_genpd_xlate_onecell NULL + +static inline int genpd_dev_pm_attach(struct device *dev) +{ + return -ENODEV; +} +#endif /* CONFIG_PM_GENERIC_DOMAINS_OF */ + +static inline int of_genpd_add_provider_simple(struct device_node *np, + struct generic_pm_domain *genpd) +{ + return __of_genpd_add_provider(np, __of_genpd_xlate_simple, genpd); +} +static inline int of_genpd_add_provider_onecell(struct device_node *np, + struct genpd_onecell_data *data) +{ + return __of_genpd_add_provider(np, __of_genpd_xlate_onecell, data); +} + #endif /* _LINUX_PM_DOMAIN_H */ diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index e4e4121fa327..897619b11fb2 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -302,6 +302,10 @@ config PM_GENERIC_DOMAINS_RUNTIME def_bool y depends on PM_RUNTIME && PM_GENERIC_DOMAINS +config PM_GENERIC_DOMAINS_OF + def_bool y + depends on PM_GENERIC_DOMAINS && OF && !ARCH_EXYNOS + config CPU_PM bool depends on SUSPEND || CPU_IDLE |
