@@ -46,6 +46,7 @@ config IDLE_INJECT
config DTPM
bool "Power capping for Dynamic Thermal Power Management (EXPERIMENTAL)"
+ depends on OF
help
This enables support for the power capping for the dynamic
thermal power management userspace engine.
@@ -23,6 +23,7 @@
#include <linux/powercap.h>
#include <linux/slab.h>
#include <linux/mutex.h>
+#include <linux/of.h>
#include "dtpm_subsys.h"
@@ -463,14 +464,197 @@ int dtpm_register(const char *name, struct dtpm *dtpm, struct dtpm *parent)
return 0;
}
-static int __init init_dtpm(void)
+static struct dtpm *dtpm_setup_virtual(const struct dtpm_node *hierarchy,
+ struct dtpm *parent)
{
+ struct dtpm *dtpm;
+ int ret;
+
+ dtpm = kzalloc(sizeof(*dtpm), GFP_KERNEL);
+ if (!dtpm)
+ return ERR_PTR(-ENOMEM);
+ dtpm_init(dtpm, NULL);
+
+ ret = dtpm_register(hierarchy->name, dtpm, parent);
+ if (ret) {
+ pr_err("Failed to register dtpm node '%s': %d\n",
+ hierarchy->name, ret);
+ kfree(dtpm);
+ return ERR_PTR(ret);
+ }
+
+ return dtpm;
+}
+
+static struct dtpm *dtpm_setup_dt(const struct dtpm_node *hierarchy,
+ struct dtpm *parent)
+{
+ struct device_node *np;
+ int i, ret;
+
+ np = of_find_node_by_path(hierarchy->name);
+ if (!np) {
+ pr_err("Failed to find '%s'\n", hierarchy->name);
+ return ERR_PTR(-ENXIO);
+ }
+
+ for (i = 0; i < ARRAY_SIZE(dtpm_subsys); i++) {
+
+ if (!dtpm_subsys[i]->setup)
+ continue;
+
+ ret = dtpm_subsys[i]->setup(parent, np);
+ if (ret) {
+ pr_err("Failed to setup '%s': %d\n", dtpm_subsys[i]->name, ret);
+ of_node_put(np);
+ return ERR_PTR(ret);
+ }
+ }
+
+ of_node_put(np);
+
+ /*
+ * By returning a NULL pointer, we let know the caller there
+ * is no child for us as we are a leaf of the tree
+ */
+ return NULL;
+}
+
+typedef struct dtpm * (*dtpm_node_callback_t)(const struct dtpm_node *, struct dtpm *);
+
+dtpm_node_callback_t dtpm_node_callback[] = {
+ [DTPM_NODE_VIRTUAL] = dtpm_setup_virtual,
+ [DTPM_NODE_DT] = dtpm_setup_dt,
+};
+
+static int dtpm_for_each_child(const struct dtpm_node *hierarchy,
+ const struct dtpm_node *it, struct dtpm *parent)
+{
+ struct dtpm *dtpm;
+ int i, ret;
+
+ for (i = 0; hierarchy[i].name; i++) {
+
+ if (hierarchy[i].parent != it)
+ continue;
+
+ dtpm = dtpm_node_callback[hierarchy[i].type](&hierarchy[i], parent);
+
+ /*
+ * A NULL pointer means there is no children, hence we
+ * continue without going deeper in the recursivity.
+ */
+ if (!dtpm)
+ continue;
+
+ /*
+ * There are multiple reasons why the callback could
+ * fail. The generic glue is abstracting the backend
+ * and therefore it is not possible to report back or
+ * take a decision based on the error. In any case,
+ * if this call fails, it is not critical in the
+ * hierarchy creation, we can assume the underlying
+ * service is not found, so we continue without this
+ * branch in the tree but with a warning to log the
+ * information the node was not created.
+ */
+ if (IS_ERR(dtpm)) {
+ pr_warn("Failed to create '%s' in the hierarchy\n",
+ hierarchy[i].name);
+ continue;
+ }
+
+ ret = dtpm_for_each_child(hierarchy, &hierarchy[i], dtpm);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+/**
+ * dtpm_create_hierarchy - Create the dtpm hierarchy
+ * @hierarchy: An array of struct dtpm_node describing the hierarchy
+ *
+ * The function is called by the platform specific code with the
+ * description of the different node in the hierarchy. It creates the
+ * tree in the sysfs filesystem under the powercap dtpm entry.
+ *
+ * The expected tree has the format:
+ *
+ * struct dtpm_node hierarchy[] = {
+ * [0] { .name = "topmost", type = DTPM_NODE_VIRTUAL },
+ * [1] { .name = "package", .type = DTPM_NODE_VIRTUAL, .parent = &hierarchy[0] },
+ * [2] { .name = "/cpus/cpu0", .type = DTPM_NODE_DT, .parent = &hierarchy[1] },
+ * [3] { .name = "/cpus/cpu1", .type = DTPM_NODE_DT, .parent = &hierarchy[1] },
+ * [4] { .name = "/cpus/cpu2", .type = DTPM_NODE_DT, .parent = &hierarchy[1] },
+ * [5] { .name = "/cpus/cpu3", .type = DTPM_NODE_DT, .parent = &hierarchy[1] },
+ * [6] { }
+ * };
+ *
+ * The last element is always an empty one and marks the end of the
+ * array.
+ *
+ * Return: zero on success, a negative value in case of error. Errors
+ * are reported back from the underlying functions.
+ */
+int dtpm_create_hierarchy(struct of_device_id *dtpm_match_table)
+{
+ const struct of_device_id *match;
+ const struct dtpm_node *hierarchy;
+ struct device_node *np;
+ int i, ret;
+
+ if (pct)
+ return -EBUSY;
+
pct = powercap_register_control_type(NULL, "dtpm", NULL);
if (IS_ERR(pct)) {
pr_err("Failed to register control type\n");
- return PTR_ERR(pct);
+ ret = PTR_ERR(pct);
+ goto out_pct;
+ }
+
+ ret = -ENODEV;
+ np = of_find_node_by_path("/");
+ if (!np)
+ goto out_err;
+
+ match = of_match_node(dtpm_match_table, np);
+
+ of_node_put(np);
+
+ if (!match)
+ goto out_err;
+
+ hierarchy = match->data;
+ if (!hierarchy) {
+ ret = -EFAULT;
+ goto out_err;
+ }
+
+ ret = dtpm_for_each_child(hierarchy, NULL, NULL);
+ if (ret)
+ goto out_err;
+
+ for (i = 0; i < ARRAY_SIZE(dtpm_subsys); i++) {
+
+ if (!dtpm_subsys[i]->init)
+ continue;
+
+ ret = dtpm_subsys[i]->init();
+ if (ret)
+ pr_info("Failed to initialze '%s': %d",
+ dtpm_subsys[i]->name, ret);
}
return 0;
+
+out_err:
+ powercap_unregister_control_type(pct);
+out_pct:
+ pct = NULL;
+
+ return ret;
}
-late_initcall(init_dtpm);
+EXPORT_SYMBOL_GPL(dtpm_create_hierarchy);
@@ -32,9 +32,23 @@ struct dtpm_ops {
void (*release)(struct dtpm *);
};
+struct device_node;
+
struct dtpm_subsys_ops {
const char *name;
int (*init)(void);
+ int (*setup)(struct dtpm *, struct device_node *);
+};
+
+enum DTPM_NODE_TYPE {
+ DTPM_NODE_VIRTUAL = 0,
+ DTPM_NODE_DT,
+};
+
+struct dtpm_node {
+ enum DTPM_NODE_TYPE type;
+ const char *name;
+ struct dtpm_node *parent;
};
static inline struct dtpm *to_dtpm(struct powercap_zone *zone)
@@ -52,4 +66,5 @@ void dtpm_unregister(struct dtpm *dtpm);
int dtpm_register(const char *name, struct dtpm *dtpm, struct dtpm *parent);
+int dtpm_create_hierarchy(struct of_device_id *dtpm_match_table);
#endif