* [PATCH v1 2/4] powercap: dtpm: Use generic powercap hierarchy helpers
2026-08-19 16:56 [PATCH v1 0/4] powercap: dtpm: Use generic hierarchy helpers and add RK3588 support Daniel Lezcano
2026-08-19 16:56 ` [PATCH v1 1/4] powercap: dtpm: Remove duplicate RK3399 CPU hierarchy nodes Daniel Lezcano
@ 2026-08-19 16:56 ` Daniel Lezcano
2026-08-19 16:56 ` [PATCH v1 3/4] powercap: dtpm: Rename Rockchip virtual node descriptor Daniel Lezcano
2026-08-19 16:56 ` [PATCH v1 4/4] powercap: dtpm: Add RK3588 hierarchy Daniel Lezcano
3 siblings, 0 replies; 5+ messages in thread
From: Daniel Lezcano @ 2026-08-19 16:56 UTC (permalink / raw)
To: daniel.lezcano, rafael; +Cc: linux-kernel, linux-pm
DTPM implements its own hierarchy creation and destruction logic while
the powercap core now provides generic helpers for this purpose.
Convert DTPM to use the generic powercap hierarchy infrastructure.
Duplicate the platform hierarchy before creating it, and use
powercap_hierarchy_create() and powercap_hierarchy_destroy() to manage
the DTPM zones.
Add DTPM callbacks to create and destroy the zones associated with each
powercap hierarchy node. Adapt the CPU and devfreq backends to return
the created DTPM instance and use the node name provided by the
hierarchy.
Convert the Rockchip RK3399 description to struct powercap_hierarchy
and keep the device tree path as DTPM-specific node data.
This removes the DTPM-specific hierarchy traversal and destruction code
and leaves the hierarchy management to the powercap core.
Signed-off-by: Daniel Lezcano <daniel.lezcano@oss.qualcomm.com>
---
drivers/powercap/dtpm.c | 165 ++++++++++++++------------------
drivers/powercap/dtpm_cpu.c | 22 ++---
drivers/powercap/dtpm_devfreq.c | 22 +++--
drivers/soc/rockchip/dtpm.c | 67 +++++++++----
include/linux/dtpm.h | 5 +-
5 files changed, 147 insertions(+), 134 deletions(-)
diff --git a/drivers/powercap/dtpm.c b/drivers/powercap/dtpm.c
index b7a65e543f19..d719f9595ec5 100644
--- a/drivers/powercap/dtpm.c
+++ b/drivers/powercap/dtpm.c
@@ -35,6 +35,7 @@ static const char *constraint_name[] = {
static DEFINE_MUTEX(dtpm_lock);
static struct powercap_control_type *pct;
+static struct powercap_hierarchy *dtpm_hierarchy;
static struct dtpm *root;
static int get_time_window_us(struct powercap_zone *pcz, int cid, u64 *window)
@@ -412,8 +413,7 @@ int dtpm_register(const char *name, struct dtpm *dtpm, struct dtpm *parent)
return 0;
}
-static struct dtpm *dtpm_setup_virtual(const struct dtpm_node *hierarchy,
- struct dtpm *parent)
+static struct dtpm *dtpm_setup_virtual(const char *name, struct dtpm *parent)
{
struct dtpm *dtpm;
int ret;
@@ -423,10 +423,9 @@ static struct dtpm *dtpm_setup_virtual(const struct dtpm_node *hierarchy,
return ERR_PTR(-ENOMEM);
dtpm_init(dtpm, NULL);
- ret = dtpm_register(hierarchy->name, dtpm, parent);
+ ret = dtpm_register(name, dtpm, parent);
if (ret) {
- pr_err("Failed to register dtpm node '%s': %d\n",
- hierarchy->name, ret);
+ pr_err("Failed to register dtpm node '%s': %d\n", name, ret);
kfree(dtpm);
return ERR_PTR(ret);
}
@@ -434,90 +433,84 @@ static struct dtpm *dtpm_setup_virtual(const struct dtpm_node *hierarchy,
return dtpm;
}
-static struct dtpm *dtpm_setup_dt(const struct dtpm_node *hierarchy,
+static struct dtpm *dtpm_setup_dt(const char *name, const char *path,
struct dtpm *parent)
{
struct device_node *np;
- int i, ret;
+ struct dtpm *dtpm = NULL;
+ int i;
- np = of_find_node_by_path(hierarchy->name);
+ np = of_find_node_by_path(path);
if (!np) {
- pr_err("Failed to find '%s'\n", hierarchy->name);
+ pr_err("Failed to find '%s'\n", path);
return ERR_PTR(-ENXIO);
}
for (i = 0; i < ARRAY_SIZE(dtpm_subsys); i++) {
+ struct dtpm *tmp;
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);
+ tmp = dtpm_subsys[i]->setup(parent, np, name);
+ if (IS_ERR(tmp)) {
+ pr_err("Failed to setup '%s': %ld\n",
+ dtpm_subsys[i]->name, PTR_ERR(tmp));
+ dtpm = tmp;
+ break;
+ }
+
+ if (tmp) {
+ dtpm = tmp;
+ break;
}
}
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;
+ return dtpm;
}
-typedef struct dtpm * (*dtpm_node_callback_t)(const struct dtpm_node *, struct dtpm *);
-
-static 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)
+static struct powercap_zone *
+dtpm_node_create(struct powercap_control_type *pct, const char *name,
+ void *data, struct powercap_zone *parent)
{
+ struct dtpm_node *node = data;
+ struct dtpm *dtpm_parent = parent ? to_dtpm(parent) : NULL;
struct dtpm *dtpm;
- int i, ret;
- for (i = 0; hierarchy[i].name; i++) {
+ if (!node)
+ return ERR_PTR(-EINVAL);
+
+ switch (node->type) {
+ case DTPM_NODE_VIRTUAL:
+ dtpm = dtpm_setup_virtual(name, dtpm_parent);
+ break;
+ case DTPM_NODE_DT:
+ dtpm = dtpm_setup_dt(name, node->path, dtpm_parent);
+ break;
+ default:
+ return ERR_PTR(-EINVAL);
+ }
- if (hierarchy[i].parent != it)
- continue;
+ if (IS_ERR(dtpm))
+ return ERR_CAST(dtpm);
- dtpm = dtpm_node_callback[hierarchy[i].type](&hierarchy[i], parent);
+ if (!dtpm)
+ return ERR_PTR(-ENODEV);
- /*
- * A NULL pointer means there is no children, hence we
- * continue without going deeper in the recursivity.
- */
- if (!dtpm)
- continue;
+ return &dtpm->zone;
+}
- /*
- * 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;
- }
+static void dtpm_node_destroy(struct powercap_control_type *pct,
+ struct powercap_zone *zone, void *data)
+{
+ struct dtpm *dtpm = to_dtpm(zone);
- ret = dtpm_for_each_child(hierarchy, &hierarchy[i], dtpm);
- if (ret)
- return ret;
- }
+ if (dtpm == root)
+ root = NULL;
- return 0;
+ dtpm_unregister(dtpm);
}
/**
@@ -528,27 +521,16 @@ static int dtpm_for_each_child(const struct dtpm_node *hierarchy,
* 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.
+ * The platform description is a struct powercap_hierarchy. The private
+ * data associated with each powercap node describes how DTPM creates the
+ * corresponding zone.
*
* 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 dtpm_node *hierarchy;
+ const struct powercap_hierarchy *hierarchy;
int i, ret;
mutex_lock(&dtpm_lock);
@@ -571,9 +553,17 @@ int dtpm_create_hierarchy(struct of_device_id *dtpm_match_table)
goto out_err;
}
- ret = dtpm_for_each_child(hierarchy, NULL, NULL);
- if (ret)
+ dtpm_hierarchy = powercap_hierarchy_dup(hierarchy);
+ if (IS_ERR(dtpm_hierarchy)) {
+ ret = PTR_ERR(dtpm_hierarchy);
+ dtpm_hierarchy = NULL;
goto out_err;
+ }
+
+ ret = powercap_hierarchy_create(pct, dtpm_hierarchy,
+ dtpm_node_create, dtpm_node_destroy);
+ if (ret)
+ goto out_free_hierarchy;
for (i = 0; i < ARRAY_SIZE(dtpm_subsys); i++) {
@@ -590,6 +580,9 @@ int dtpm_create_hierarchy(struct of_device_id *dtpm_match_table)
return 0;
+out_free_hierarchy:
+ powercap_hierarchy_free(dtpm_hierarchy);
+ dtpm_hierarchy = NULL;
out_err:
powercap_unregister_control_type(pct);
out_pct:
@@ -601,20 +594,6 @@ int dtpm_create_hierarchy(struct of_device_id *dtpm_match_table)
}
EXPORT_SYMBOL_GPL(dtpm_create_hierarchy);
-static void __dtpm_destroy_hierarchy(struct dtpm *dtpm)
-{
- struct dtpm *child, *aux;
-
- list_for_each_entry_safe(child, aux, &dtpm->children, sibling)
- __dtpm_destroy_hierarchy(child);
-
- /*
- * At this point, we know all children were removed from the
- * recursive call before
- */
- dtpm_unregister(dtpm);
-}
-
void dtpm_destroy_hierarchy(void)
{
int i;
@@ -624,7 +603,7 @@ void dtpm_destroy_hierarchy(void)
if (!pct)
goto out_unlock;
- __dtpm_destroy_hierarchy(root);
+ powercap_hierarchy_destroy(pct, dtpm_hierarchy, dtpm_node_destroy);
for (i = 0; i < ARRAY_SIZE(dtpm_subsys); i++) {
@@ -635,8 +614,10 @@ void dtpm_destroy_hierarchy(void)
dtpm_subsys[i]->exit();
}
+ powercap_hierarchy_free(dtpm_hierarchy);
powercap_unregister_control_type(pct);
+ dtpm_hierarchy = NULL;
pct = NULL;
root = NULL;
diff --git a/drivers/powercap/dtpm_cpu.c b/drivers/powercap/dtpm_cpu.c
index 21355db6419d..c8e02eda701c 100644
--- a/drivers/powercap/dtpm_cpu.c
+++ b/drivers/powercap/dtpm_cpu.c
@@ -189,22 +189,21 @@ static int cpuhp_dtpm_cpu_online(unsigned int cpu)
return 0;
}
-static int __dtpm_cpu_setup(int cpu, struct dtpm *parent)
+static struct dtpm *__dtpm_cpu_setup(int cpu, struct dtpm *parent, const char *name)
{
struct dtpm_cpu *dtpm_cpu;
struct cpufreq_policy *policy;
struct em_perf_state *table;
struct em_perf_domain *pd;
- char name[CPUFREQ_NAME_LEN];
- int ret = -ENOMEM;
+ int ret;
dtpm_cpu = per_cpu(dtpm_per_cpu, cpu);
if (dtpm_cpu)
- return 0;
+ return NULL;
policy = cpufreq_cpu_get(cpu);
if (!policy)
- return 0;
+ return NULL;
pd = em_cpu_get(cpu);
if (!pd || em_is_artificial(pd)) {
@@ -224,8 +223,6 @@ static int __dtpm_cpu_setup(int cpu, struct dtpm *parent)
for_each_cpu(cpu, policy->related_cpus)
per_cpu(dtpm_per_cpu, cpu) = dtpm_cpu;
- snprintf(name, sizeof(name), "cpu%d-cpufreq", dtpm_cpu->cpu);
-
ret = dtpm_register(name, &dtpm_cpu->dtpm, parent);
if (ret)
goto out_kfree_dtpm_cpu;
@@ -240,7 +237,7 @@ static int __dtpm_cpu_setup(int cpu, struct dtpm *parent)
goto out_dtpm_unregister;
cpufreq_cpu_put(policy);
- return 0;
+ return &dtpm_cpu->dtpm;
out_dtpm_unregister:
dtpm_unregister(&dtpm_cpu->dtpm);
@@ -253,18 +250,19 @@ static int __dtpm_cpu_setup(int cpu, struct dtpm *parent)
release_policy:
cpufreq_cpu_put(policy);
- return ret;
+ return ERR_PTR(ret);
}
-static int dtpm_cpu_setup(struct dtpm *dtpm, struct device_node *np)
+static struct dtpm *dtpm_cpu_setup(struct dtpm *dtpm, struct device_node *np,
+ const char *name)
{
int cpu;
cpu = of_cpu_node_to_id(np);
if (cpu < 0)
- return 0;
+ return NULL;
- return __dtpm_cpu_setup(cpu, dtpm);
+ return __dtpm_cpu_setup(cpu, dtpm, name);
}
static int dtpm_cpu_init(void)
diff --git a/drivers/powercap/dtpm_devfreq.c b/drivers/powercap/dtpm_devfreq.c
index fa71285dee60..a783601fe74e 100644
--- a/drivers/powercap/dtpm_devfreq.c
+++ b/drivers/powercap/dtpm_devfreq.c
@@ -144,7 +144,8 @@ static struct dtpm_ops dtpm_ops = {
.release = pd_release,
};
-static int __dtpm_devfreq_setup(struct devfreq *devfreq, struct dtpm *parent)
+static struct dtpm *__dtpm_devfreq_setup(struct devfreq *devfreq,
+ struct dtpm *parent, const char *name)
{
struct device *dev = devfreq->dev.parent;
struct dtpm_devfreq *dtpm_devfreq;
@@ -156,23 +157,23 @@ static int __dtpm_devfreq_setup(struct devfreq *devfreq, struct dtpm *parent)
ret = dev_pm_opp_of_register_em(dev, NULL);
if (ret) {
pr_err("No energy model available for '%s'\n", dev_name(dev));
- return -EINVAL;
+ return ERR_PTR(-EINVAL);
}
}
dtpm_devfreq = kzalloc_obj(*dtpm_devfreq);
if (!dtpm_devfreq)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);
dtpm_init(&dtpm_devfreq->dtpm, &dtpm_ops);
dtpm_devfreq->devfreq = devfreq;
- ret = dtpm_register(dev_name(dev), &dtpm_devfreq->dtpm, parent);
+ ret = dtpm_register(name, &dtpm_devfreq->dtpm, parent);
if (ret) {
pr_err("Failed to register '%s': %d\n", dev_name(dev), ret);
kfree(dtpm_devfreq);
- return ret;
+ return ERR_PTR(ret);
}
ret = dev_pm_qos_add_request(dev, &dtpm_devfreq->qos_req,
@@ -185,23 +186,24 @@ static int __dtpm_devfreq_setup(struct devfreq *devfreq, struct dtpm *parent)
dtpm_update_power(&dtpm_devfreq->dtpm);
- return 0;
+ return &dtpm_devfreq->dtpm;
out_dtpm_unregister:
dtpm_unregister(&dtpm_devfreq->dtpm);
- return ret;
+ return ERR_PTR(ret);
}
-static int dtpm_devfreq_setup(struct dtpm *dtpm, struct device_node *np)
+static struct dtpm *dtpm_devfreq_setup(struct dtpm *dtpm, struct device_node *np,
+ const char *name)
{
struct devfreq *devfreq;
devfreq = devfreq_get_devfreq_by_node(np);
if (IS_ERR(devfreq))
- return 0;
+ return NULL;
- return __dtpm_devfreq_setup(devfreq, dtpm);
+ return __dtpm_devfreq_setup(devfreq, dtpm, name);
}
struct dtpm_subsys_ops dtpm_devfreq_ops = {
diff --git a/drivers/soc/rockchip/dtpm.c b/drivers/soc/rockchip/dtpm.c
index e6a0c607334b..451417ae5715 100644
--- a/drivers/soc/rockchip/dtpm.c
+++ b/drivers/soc/rockchip/dtpm.c
@@ -11,26 +11,59 @@
#include <linux/of.h>
#include <linux/platform_device.h>
-static struct dtpm_node __initdata rk3399_hierarchy[] = {
- [0] = { .name = "rk3399",
- .type = DTPM_NODE_VIRTUAL },
- [1] = { .name = "package",
- .type = DTPM_NODE_VIRTUAL,
- .parent = &rk3399_hierarchy[0] },
- [2] = { .name = "/cpus/cpu@0",
- .type = DTPM_NODE_DT,
- .parent = &rk3399_hierarchy[1] },
- [3] = { .name = "/cpus/cpu@100",
- .type = DTPM_NODE_DT,
- .parent = &rk3399_hierarchy[1] },
- [4] = { .name = "/gpu@ff9a0000",
- .type = DTPM_NODE_DT,
- .parent = &rk3399_hierarchy[1] },
- [5] = { /* sentinel */ }
+static struct dtpm_node rk3399_virtual = {
+ .type = DTPM_NODE_VIRTUAL,
+};
+
+static struct dtpm_node rk3399_cpu0 = {
+ .type = DTPM_NODE_DT,
+ .path = "/cpus/cpu@0",
+};
+
+static struct dtpm_node rk3399_cpu4 = {
+ .type = DTPM_NODE_DT,
+ .path = "/cpus/cpu@100",
+};
+
+static struct dtpm_node rk3399_gpu = {
+ .type = DTPM_NODE_DT,
+ .path = "/gpu@ff9a0000",
+};
+
+static struct powercap_node __initdata rk3399_nodes[] = {
+ [0] = {
+ .name = "rk3399",
+ .data = &rk3399_virtual,
+ },
+ [1] = {
+ .name = "package",
+ .parent = &rk3399_nodes[0],
+ .data = &rk3399_virtual,
+ },
+ [2] = {
+ .name = "cpu0-cpufreq",
+ .parent = &rk3399_nodes[1],
+ .data = &rk3399_cpu0,
+ },
+ [3] = {
+ .name = "cpu4-cpufreq",
+ .parent = &rk3399_nodes[1],
+ .data = &rk3399_cpu4,
+ },
+ [4] = {
+ .name = "ff9a0000.gpu",
+ .parent = &rk3399_nodes[1],
+ .data = &rk3399_gpu,
+ },
+};
+
+static struct powercap_hierarchy __initdata rk3399_hierarchy = {
+ .nodes = rk3399_nodes,
+ .nr_nodes = ARRAY_SIZE(rk3399_nodes),
};
static struct of_device_id __initdata rockchip_dtpm_match_table[] = {
- { .compatible = "rockchip,rk3399", .data = rk3399_hierarchy },
+ { .compatible = "rockchip,rk3399", .data = &rk3399_hierarchy },
{},
};
diff --git a/include/linux/dtpm.h b/include/linux/dtpm.h
index a4a13514b730..c0ece6a4d1fe 100644
--- a/include/linux/dtpm.h
+++ b/include/linux/dtpm.h
@@ -38,7 +38,7 @@ struct dtpm_subsys_ops {
const char *name;
int (*init)(void);
void (*exit)(void);
- int (*setup)(struct dtpm *, struct device_node *);
+ struct dtpm *(*setup)(struct dtpm *, struct device_node *, const char *);
};
enum DTPM_NODE_TYPE {
@@ -48,8 +48,7 @@ enum DTPM_NODE_TYPE {
struct dtpm_node {
enum DTPM_NODE_TYPE type;
- const char *name;
- struct dtpm_node *parent;
+ const char *path;
};
static inline struct dtpm *to_dtpm(struct powercap_zone *zone)
--
2.43.0
^ permalink raw reply related [flat|nested] 5+ messages in thread