new file mode 100644
@@ -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".
@@ -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
@@ -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 */
@@ -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