+++ /dev/null
-* Generic power domains
-
-System on chip designs are often divided into multiple power 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 power domain consumer devices
-with their power domains provided by power domain providers. A power domain
-provider can be represented by any node in the device tree and can provide
-one or more power domains. A consumer node can refer to the provider by
-a phandle and a set of phandle arguments (so called power domain specifier)
-of length specified by #power-domain-cells property in the power domain
-provider node.
-
-==Power domain providers==
-
-Required properties:
- - #power-domain-cells : Number of cells in a power domain specifier;
- Typically 0 for nodes representing a single power domain and 1 for nodes
- providing multiple power 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 power domain provider
-and expects one cell as its phandle argument.
-
-==Power domain consumers==
-
-Required properties:
- - power-domains : A phandle and power domain specifier as defined by bindings
- of 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 power domain consumer device, which is located
-inside power domain with index 0 of power controller represented by node with
-label "power".
#include <linux/init.h>
#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>
list_add(&genpd->gpd_list_node, &gpd_list);
mutex_unlock(&gpd_list_lock);
}
-
-#ifdef CONFIG_PM_GENERIC_DOMAINS_OF
-/*
- * Device Tree based power domain providers.
- *
- * The code below implements generic device tree based power domain providers
- * that bind device tree nodes with generic power domains registered in the
- * system.
- *
- * Any driver that registers generic power domains and need to support binding
- * of devices to these domains is supposed to register a power domain provider,
- * which maps a power domain specifier retrieved from device tree to a power
- * domain.
- *
- * Two simple mapping functions have been provided for convenience:
- * - of_genpd_xlate_simple() for 1:1 device tree node to domain mapping,
- * - of_genpd_xlate_onecell() for mapping of multiple domains per node
- * by index.
- */
-
-/**
- * struct of_genpd_provider - Power domain provider registration structure
- * @link: Entry in global list of domain providers
- * @node: Pointer to device tree node of domain provider
- * @xlate: Provider-specific xlate callback mapping a set of specifier cells
- * into a power 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 power 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 power domain
- * @data: xlate function private data - pointer to struct generic_pm_domain
- *
- * This is a generic xlate function that can be used to model power 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 for providers using single index.
- * @genpdspec: OF phandle args to map into a power 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 power
- * domain controllers that have one device tree node and provide multiple
- * power domains. A single cell is used as an index to an array of power
- * domains specified in 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->domain_num) {
- pr_err("%s: invalid domain index %d\n", __func__, idx);
- return ERR_PTR(-EINVAL);
- }
-
- return genpd_data->domains[idx];
-}
-EXPORT_SYMBOL_GPL(of_genpd_xlate_onecell);
-
-/**
- * of_genpd_add_provider() - Register a domain provider for a node
- * @np: Device node pointer associated with domain provider.
- * @xlate: Callback for decoding domain from phandle arguments.
- * @data: Context pointer for @genpd_src_get 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 domain provider
- * @np: Device node pointer associated with 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 power domain
- * @genpdspec: OF phandle args to use for look-up
- *
- * Looks for domain provider under node specified by @genpdspec and if found
- * uses xlate function of the provider to map phandle args to a power 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(-EPROBE_DEFER);
- 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;
-}
-
-/*
- * Device<->domain binding using Device Tree look-up.
- *
- * The purpose of code below is to manage assignment of devices to their
- * power domains in an automatic fashion, based on data read from device tree.
- * The two functions, genpd_bind_domain() and genpd_unbind_domain() are
- * intended to be called by higher level code that manages devices, i.e.
- * really_probe() and __device_release_driver() to respectively bind and
- * unbind device from its power domain.
- *
- * Both generic and legacy Samsung-specific DT bindings are supported to
- * keep backwards compatibility with existing DTBs.
- */
-
-/**
- * genpd_bind_domain - Bind device to its power domain using Device Tree.
- * @dev: Device to bind to its power domain.
- *
- * Tries to parse power domain specifier from device's OF node and if succeeds
- * attaches the device to retrieved power domain.
- *
- * Returns 0 on success or negative error code otherwise.
- */
-int genpd_bind_domain(struct device *dev)
-{
- struct of_phandle_args pd_args;
- struct generic_pm_domain *pd;
- int ret;
-
- if (!dev->of_node)
- return 0;
-
- 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 0;
- }
-
- pd = of_genpd_get_from_provider(&pd_args);
- if (IS_ERR(pd)) {
- if (PTR_ERR(pd) != -EPROBE_DEFER)
- dev_err(dev, "failed to find power domain: %ld\n",
- PTR_ERR(pd));
- return PTR_ERR(pd);
- }
-
- dev_dbg(dev, "adding to power 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 power domain %s: %d",
- pd->name, ret);
- return ret;
- }
-
- return 0;
-}
-
-/**
- * genpd_unbind_domain - Unbind device from its power domain.
- * @dev: Device to unbind from its power domain.
- *
- * Unbinds device from power domain previously bound to it.
- *
- * Returns 0 on success or negative error code otherwise.
- */
-int genpd_unbind_domain(struct device *dev)
-{
- struct generic_pm_domain *pd = dev_to_genpd(dev);
- int ret;
-
- if (!dev->of_node || IS_ERR(pd))
- return 0;
-
- dev_dbg(dev, "removing from power 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 power domain %s: %d",
- pd->name, ret);
- return ret;
- }
-
- /* Check if domain can be powered off after removing this device. */
- genpd_queue_power_off_work(pd);
-
- return 0;
-}
-#endif
projects / karo-tx-linux.git / commitdiff