@@ -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>
#define DTPM_POWER_LIMIT_FLAG 0
@@ -461,9 +462,69 @@ int dtpm_register(const char *name, struct dtpm *dtpm, struct dtpm *parent)
return 0;
}
-static int __init init_dtpm(void)
+static int dtpm_for_each_child_of(struct device_node *root,
+ struct device_node *np, struct dtpm *parent)
{
+ struct device_node *child;
+ struct device_node *pz;
+ struct dtpm *dtpm;
+ int ret;
+
+ for_each_child_of_node(root, child) {
+
+ pz = of_parse_phandle(child, "powerzone", 0);
+ if (pz != np)
+ continue;
+
+ dtpm = kzalloc(sizeof(*dtpm), GFP_KERNEL);
+ if (!dtpm)
+ return -ENOMEM;
+
+ dtpm_init(dtpm, NULL);
+
+ ret = dtpm_register(child->name, dtpm, parent);
+ if (ret) {
+ pr_err("Failed to register dtpm node '%s'\n", child->name);
+ return ret;
+ }
+
+ dtpm_set_data(dtpm, child);
+
+ dtpm_for_each_child_of(root, child, dtpm);
+ }
+
+ return 0;
+}
+
+static int for_each_pz_dtpm(struct dtpm *dtpm, struct device_node *pz,
+ struct device_node *np, dtpm_setup_t setup)
+{
+ struct dtpm *child;
+ int ret = 0;
+
+ if (dtpm_get_data(dtpm) == pz && setup) {
+ ret = setup(dtpm, np);
+ if (ret)
+ return ret;
+ }
+
+ list_for_each_entry(child, &dtpm->children, sibling)
+ ret |= for_each_pz_dtpm(child, pz, np, setup);
+
+ return ret;
+}
+
+static int dtpm_probe(void)
+{
+ struct device_node *np;
+ struct device_node *pz;
+
struct dtpm_descr *dtpm_descr;
+ int ret;
+
+ np = of_find_node_by_name(NULL, "powerzones");
+ if (!np)
+ return 0;
pct = powercap_register_control_type(NULL, "dtpm", NULL);
if (IS_ERR(pct)) {
@@ -471,9 +532,35 @@ static int __init init_dtpm(void)
return PTR_ERR(pct);
}
- for_each_dtpm_table(dtpm_descr)
- dtpm_descr->init();
+ ret = dtpm_for_each_child_of(np, NULL, NULL);
+ if (ret) {
+ pr_err("Failed to read powerzones hierarchy: %d\n", ret);
+ goto out_release;
+ }
+ for_each_node_with_property(np, "powerzone") {
+
+ pz = of_parse_phandle(np, "powerzone", 0);
+
+ of_node_put(np);
+ if (!pz)
+ continue;
+
+ for_each_dtpm_table(dtpm_descr)
+ for_each_pz_dtpm(root, pz, np, dtpm_descr->setup);
+
+ of_node_put(pz);
+ }
+
+ for_each_dtpm_table(dtpm_descr)
+ if (dtpm_descr->init)
+ dtpm_descr->init();
+
return 0;
+
+out_release:
+ powercap_unregister_control_type(pct);
+
+ return ret;
}
-late_initcall(init_dtpm);
+late_initcall(dtpm_probe);
@@ -269,4 +269,4 @@ static int __init dtpm_cpu_init(void)
return 0;
}
-DTPM_DECLARE(dtpm_cpu, dtpm_cpu_init);
+DTPM_DECLARE(dtpm_cpu, dtpm_cpu_init, NULL);
@@ -32,23 +32,28 @@ struct dtpm_ops {
void (*release)(struct dtpm *);
};
+struct device_node;
+
typedef int (*dtpm_init_t)(void);
+typedef int (*dtpm_setup_t)(struct dtpm *, struct device_node *);
struct dtpm_descr {
dtpm_init_t init;
+ dtpm_setup_t setup;
};
/* Init section thermal table */
extern struct dtpm_descr __dtpm_table[];
extern struct dtpm_descr __dtpm_table_end[];
-#define DTPM_TABLE_ENTRY(name, __init) \
+#define DTPM_TABLE_ENTRY(name, __init, __setup) \
static struct dtpm_descr __dtpm_table_entry_##name \
__used __section("__dtpm_table") = { \
.init = __init, \
+ .setup = __setup, \
}
-#define DTPM_DECLARE(name, init) DTPM_TABLE_ENTRY(name, init)
+#define DTPM_DECLARE(name, init, setup) DTPM_TABLE_ENTRY(name, init, setup)
#define for_each_dtpm_table(__dtpm) \
for (__dtpm = __dtpm_table; \
@@ -60,6 +65,16 @@ static inline struct dtpm *to_dtpm(struct powercap_zone *zone)
return container_of(zone, struct dtpm, zone);
}
+static inline void dtpm_set_data(struct dtpm *dtpm, void *data)
+{
+ powercap_set_zone_data(&dtpm->zone, data);
+}
+
+static inline void *dtpm_get_data(struct dtpm *dtpm)
+{
+ return powercap_get_zone_data(&dtpm->zone);
+}
+
int dtpm_update_power(struct dtpm *dtpm);
int dtpm_release_zone(struct powercap_zone *pcz);
The DTPM framework is available but without a way to configure it. These changes add DT support to initialize the powercap hierarchy via the powerzones description. It acts in two steps. First it reads the powerzone dependencies and build the DTPM hierarchy. Second, it search for all devices which belongs to a powerzone and attach them to the hierarchy. This approach makes the initialization self-encapsulated for the DTPM components. In order to ensure a nice self-encapsulation, the DTPM table descriptors contains a couple of initialization functions, one to setup the DTPM backend and one to initialize it up. With this approach, the DTPM framework has a very few functions to export. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> --- drivers/powercap/Kconfig | 1 + drivers/powercap/dtpm.c | 95 +++++++++++++++++++++++++++++++++++-- drivers/powercap/dtpm_cpu.c | 2 +- include/linux/dtpm.h | 19 +++++++- 4 files changed, 110 insertions(+), 7 deletions(-)