diff options
Diffstat (limited to 'drivers/powercap')
| -rw-r--r-- | drivers/powercap/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/powercap/dtpm.c | 190 |
2 files changed, 188 insertions, 3 deletions
diff --git a/drivers/powercap/Kconfig b/drivers/powercap/Kconfig index 8242e8c5ed77..b1ca339957e3 100644 --- a/drivers/powercap/Kconfig +++ b/drivers/powercap/Kconfig @@ -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. diff --git a/drivers/powercap/dtpm.c b/drivers/powercap/dtpm.c index 0e5c93443c70..414826a1509b 100644 --- a/drivers/powercap/dtpm.c +++ b/drivers/powercap/dtpm.c @@ -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); |