[PATCH net-next v5 04/12] net: pse-pd: Add support for PSE power domains

Kory Maincent
2025-02-18T16:19:23Z

From: Kory Maincent (Dent Project) <kory.maincent@bootlin.com>

Introduce PSE power domain support as groundwork for upcoming port
priority features. Multiple PSE PIs can now be grouped under a single
PSE power domain, enabling future enhancements like defining available
power budgets, port priority modes, and disconnection policies. This
setup will allow the system to assess whether activating a port would
exceed the available power budget, preventing over-budget states
proactively.

Signed-off-by: Kory Maincent (Dent Project) <kory.maincent@bootlin.com>
---

Changes in v4:
- Add kdoc.
- Fix null dereference in pse_flush_pw_ds function.

Changes in v3:
- Remove pw_budget variable.

Changes in v2:
- new patch.
---
drivers/net/pse-pd/pse_core.c | 114 ++++++++++++++++++++++++++++++++++++++++++
include/linux/pse-pd/pse.h | 2 +
2 files changed, 116 insertions(+)

diff --git a/drivers/net/pse-pd/pse_core.c b/drivers/net/pse-pd/pse_core.c
index 10a5ab30afdd..a654f6eef6ff 100644
--- a/drivers/net/pse-pd/pse_core.c
+++ b/drivers/net/pse-pd/pse_core.c
@@ -15,6 +15,7 @@

static DEFINE_MUTEX(pse_list_mutex);
static LIST_HEAD(pse_controller_list);
+static DEFINE_XARRAY_ALLOC(pse_pw_d_map);

/**
* struct pse_control - a PSE control
@@ -35,6 +36,16 @@ struct pse_control {
struct phy_device *attached_phydev;
};

+/**
+ * struct pse_power_domain - a PSE power domain
+ * @id: ID of the power domain
+ * @supply: Power supply the Power Domain
+ */
+struct pse_power_domain {
+ int id;
+ struct regulator *supply;
+};
+
static int of_load_single_pse_pi_pairset(struct device_node *node,
struct pse_pi *pi,
int pairset_num)
@@ -440,6 +451,103 @@ devm_pse_pi_regulator_register(struct pse_controller_dev *pcdev,
return 0;
}

+/**
+ * pse_flush_pw_ds - flush all PSE power domains of a PSE
+ * @pcdev: a pointer to the initialized PSE controller device
+ */
+static void pse_flush_pw_ds(struct pse_controller_dev *pcdev)
+{
+ struct pse_power_domain *pw_d;
+ int i;
+
+ for (i = 0; i < pcdev->nr_lines; i++) {
+ if (!pcdev->pi[i].pw_d)
+ continue;
+
+ pw_d = xa_load(&pse_pw_d_map, pcdev->pi[i].pw_d->id);
+ if (pw_d) {
+ regulator_put(pw_d->supply);
+ xa_erase(&pse_pw_d_map, pw_d->id);
+ }
+ }
+}
+
+/**
+ * devm_pse_alloc_pw_d - allocate a new PSE power domain for a device
+ * @dev: device that is registering this PSE power domain
+ *
+ * Return: Pointer to the newly allocated PSE power domain or error pointers
+ */
+static struct pse_power_domain *devm_pse_alloc_pw_d(struct device *dev)
+{
+ struct pse_power_domain *pw_d;
+ int index, ret;
+
+ pw_d = devm_kzalloc(dev, sizeof(*pw_d), GFP_KERNEL);
+ if (!pw_d)
+ return ERR_PTR(-ENOMEM);
+
+ ret = xa_alloc(&pse_pw_d_map, &index, pw_d, XA_LIMIT(1, INT_MAX), GFP_KERNEL);
+ if (ret)
+ return ERR_PTR(ret);
+
+ pw_d->id = index;
+ return pw_d;
+}
+
+/**
+ * pse_register_pw_ds - register the PSE power domains for a PSE
+ * @pcdev: a pointer to the PSE controller device
+ *
+ * Return: 0 on success and failure value on error
+ */
+static int pse_register_pw_ds(struct pse_controller_dev *pcdev)
+{
+ int i;
+
+ for (i = 0; i < pcdev->nr_lines; i++) {
+ struct regulator_dev *rdev = pcdev->pi[i].rdev;
+ struct pse_power_domain *pw_d;
+ struct regulator *supply;
+ bool present = false;
+ unsigned long index;
+
+ /* No regulator or regulator parent supply registered.
+ * We need a regulator parent to register a PSE power domain
+ */
+ if (!rdev || !rdev->supply)
+ continue;
+
+ xa_for_each(&pse_pw_d_map, index, pw_d) {
+ /* Power supply already registered as a PSE power
+ * domain.
+ */
+ if (regulator_is_equal(pw_d->supply, rdev->supply)) {
+ present = true;
+ pcdev->pi[i].pw_d = pw_d;
+ break;
+ }
+ }
+ if (present)
+ continue;
+
+ pw_d = devm_pse_alloc_pw_d(pcdev->dev);
+ if (IS_ERR_OR_NULL(pw_d))
+ return PTR_ERR(pw_d);
+
+ supply = regulator_get(&rdev->dev, rdev->supply_name);
+ if (IS_ERR(supply)) {
+ xa_erase(&pse_pw_d_map, pw_d->id);
+ return PTR_ERR(supply);
+ }
+
+ pw_d->supply = supply;
+ pcdev->pi[i].pw_d = pw_d;
+ }
+
+ return 0;
+}
+
/**
* pse_controller_register - register a PSE controller device
* @pcdev: a pointer to the initialized PSE controller device
@@ -499,6 +607,11 @@ int pse_controller_register(struct pse_controller_dev *pcdev)
return ret;
}

+ ret = pse_register_pw_ds(pcdev);
+
+ if (ret)
+ return ret;
+
mutex_lock(&pse_list_mutex);
list_add(&pcdev->list, &pse_controller_list);
mutex_unlock(&pse_list_mutex);
@@ -513,6 +626,7 @@ EXPORT_SYMBOL_GPL(pse_controller_register);
*/
void pse_controller_unregister(struct pse_controller_dev *pcdev)
{
+ pse_flush_pw_ds(pcdev);
pse_release_pis(pcdev);
mutex_lock(&pse_list_mutex);
list_del(&pcdev->list);
diff --git a/include/linux/pse-pd/pse.h b/include/linux/pse-pd/pse.h
index 5d41a1c984bd..5201a0fb3d74 100644
--- a/include/linux/pse-pd/pse.h
+++ b/include/linux/pse-pd/pse.h
@@ -220,12 +220,14 @@ struct pse_pi_pairset {
* @np: device node pointer of the PSE PI node
* @rdev: regulator represented by the PSE PI
* @admin_state_enabled: PI enabled state
+ * @pw_d: Power domain of the PSE PI
*/
struct pse_pi {
struct pse_pi_pairset pairset[2];
struct device_node *np;
struct regulator_dev *rdev;
bool admin_state_enabled;
+ struct pse_power_domain *pw_d;
};

/**

--
2.34.1