net: pse-pd: Add support for PSE power domains

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>
Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://patch.msgid.link/20250617-feature_poe_port_prio-v14-4-78a1a645e2ee@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/pse-pd/pse_core.c b/drivers/net/pse-pd/pse_core.c
index 16cc1dc0724682b0736751b74d7c325a6f024349..f2fb7ccbc4c21aeb781fe31a9a923246fe94954f 100644 (file)
--- a/drivers/net/pse-pd/pse_core.c
+++ b/drivers/net/pse-pd/pse_core.c
@@ -16,8 +16,12 @@
 #include <linux/rtnetlink.h>
 #include <net/net_trackers.h>
 
+#define PSE_PW_D_LIMIT INT_MAX
+
 static DEFINE_MUTEX(pse_list_mutex);
 static LIST_HEAD(pse_controller_list);
+static DEFINE_XARRAY_ALLOC(pse_pw_d_map);
+static DEFINE_MUTEX(pse_pw_d_mutex);
 
 /**
  * struct pse_control - a PSE control
@@ -38,6 +42,18 @@ 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
+ * @refcnt: Number of gets of this pse_power_domain
+ */
+struct pse_power_domain {
+       int id;
+       struct regulator *supply;
+       struct kref refcnt;
+};
+
 static int of_load_single_pse_pi_pairset(struct device_node *node,
                                         struct pse_pi *pi,
                                         int pairset_num)
@@ -485,6 +501,125 @@ devm_pse_pi_regulator_register(struct pse_controller_dev *pcdev,
        return 0;
 }
 
+static void __pse_pw_d_release(struct kref *kref)
+{
+       struct pse_power_domain *pw_d = container_of(kref,
+                                                    struct pse_power_domain,
+                                                    refcnt);
+
+       regulator_put(pw_d->supply);
+       xa_erase(&pse_pw_d_map, pw_d->id);
+       mutex_unlock(&pse_pw_d_mutex);
+}
+
+/**
+ * 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)
+                       continue;
+
+               kref_put_mutex(&pw_d->refcnt, __pse_pw_d_release,
+                              &pse_pw_d_mutex);
+       }
+}
+
+/**
+ * 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, PSE_PW_D_LIMIT),
+                      GFP_KERNEL);
+       if (ret)
+               return ERR_PTR(ret);
+
+       kref_init(&pw_d->refcnt);
+       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, ret = 0;
+
+       mutex_lock(&pse_pw_d_mutex);
+       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) {
+                       kref_get(&pw_d->refcnt);
+                       continue;
+               }
+
+               pw_d = devm_pse_alloc_pw_d(pcdev->dev);
+               if (IS_ERR(pw_d)) {
+                       ret = PTR_ERR(pw_d);
+                       goto out;
+               }
+
+               supply = regulator_get(&rdev->dev, rdev->supply_name);
+               if (IS_ERR(supply)) {
+                       xa_erase(&pse_pw_d_map, pw_d->id);
+                       ret = PTR_ERR(supply);
+                       goto out;
+               }
+
+               pw_d->supply = supply;
+               pcdev->pi[i].pw_d = pw_d;
+       }
+
+out:
+       mutex_unlock(&pse_pw_d_mutex);
+       return ret;
+}
+
 /**
  * pse_controller_register - register a PSE controller device
  * @pcdev: a pointer to the initialized PSE controller device
@@ -544,6 +679,10 @@ 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);
@@ -558,6 +697,7 @@ 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 6eb064722aa8e6e0cfc8a14c0418641553878757..f736b1677ea52ff28368e9df3237166946d9d9fe 100644 (file)
--- a/include/linux/pse-pd/pse.h
+++ b/include/linux/pse-pd/pse.h
@@ -222,12 +222,14 @@ 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;
 };
 
 /**