@@ -2441,6 +2441,9 @@ static LIST_HEAD(of_genpd_providers);
/* Mutex to protect the list above. */
static DEFINE_MUTEX(of_genpd_mutex);
+static int of_genpd_parse_domains_map(struct device_node *np,
+ struct genpd_onecell_data *data);
+
/**
* genpd_xlate_simple() - Xlate function for direct node-domain mapping
* @genpdspec: OF phandle args to map into a PM domain
@@ -2635,6 +2638,14 @@ int of_genpd_add_provider_onecell(struct device_node *np,
if (ret < 0)
goto error;
+ /* Parse power-domains-map property for Nexus node mapping */
+ ret = of_genpd_parse_domains_map(np, data);
+ if (ret < 0 && ret != -ENOENT) {
+ pr_err("Failed to parse power-domains-map for %pOF: %d\n", np, ret);
+ of_genpd_del_provider(np);
+ goto error;
+ }
+
return 0;
error:
@@ -2734,6 +2745,161 @@ static struct generic_pm_domain *genpd_get_from_provider(
return genpd;
}
+/**
+ * of_genpd_parse_domains_map() - Parse power-domains-map property for Nexus mapping
+ * @np: Device node pointer associated with the PM domain provider.
+ * @data: Pointer to the onecell data associated with the PM domain provider.
+ *
+ * Parse the power-domains-map property to establish parent-child relationships
+ * for PM domains using Nexus node mapping as defined in the device tree
+ * specification section v2.5.1.
+ *
+ * The power-domains-map property format is:
+ * power-domains-map = <child_specifier target_phandle [target_specifier]>, ...;
+ *
+ * Where:
+ * - child_specifier: The child domain ID that should be mapped
+ * - target_phandle: Phandle to the parent PM domain provider
+ * - target_specifier: Optional arguments for the parent provider (if it has #power-domain-cells > 0)
+ *
+ * Returns 0 on success, -ENOENT if property doesn't exist, or negative error code.
+ */
+static int of_genpd_parse_domains_map(struct device_node *np,
+ struct genpd_onecell_data *data)
+{
+ struct of_phandle_args parent_args;
+ struct generic_pm_domain *parent_genpd, *child_genpd;
+ u32 *map_entries;
+ int map_len, child_cells, i, ret;
+ u32 child_id;
+
+ /* Check if power-domains-map property exists */
+ map_len = of_property_count_u32_elems(np, "power-domains-map");
+ if (map_len <= 0)
+ return -ENOENT;
+
+ /* Get #power-domain-cells from this node (should be 1 for onecell) */
+ ret = of_property_read_u32(np, "#power-domain-cells", &child_cells);
+ if (ret) {
+ pr_err("Missing #power-domain-cells property for %pOF\n", np);
+ return ret;
+ }
+
+ if (child_cells != 1) {
+ pr_err("power-domains-map only supported for #power-domain-cells = 1, got %u for %pOF\n",
+ child_cells, np);
+ return -EINVAL;
+ }
+
+ map_entries = kcalloc(map_len, sizeof(*map_entries), GFP_KERNEL);
+ if (!map_entries)
+ return -ENOMEM;
+
+ ret = of_property_read_u32_array(np, "power-domains-map", map_entries, map_len);
+ if (ret) {
+ pr_err("Failed to read power-domains-map for %pOF: %d\n", np, ret);
+ goto out_free;
+ }
+
+ /* Parse the map entries */
+ i = 0;
+ while (i < map_len) {
+ struct device_node *parent_np;
+ u32 parent_cells;
+
+ /* Extract child domain ID */
+ if (i >= map_len) {
+ pr_err("Incomplete power-domains-map entry at index %d for %pOF\n", i, np);
+ ret = -EINVAL;
+ goto out_free;
+ }
+ child_id = map_entries[i++];
+
+ /* Extract parent phandle */
+ if (i >= map_len) {
+ pr_err("Missing parent phandle in power-domains-map at index %d for %pOF\n", i, np);
+ ret = -EINVAL;
+ goto out_free;
+ }
+ parent_np = of_find_node_by_phandle(map_entries[i++]);
+ if (!parent_np) {
+ pr_err("Invalid parent phandle 0x%x in power-domains-map for %pOF\n",
+ map_entries[i-1], np);
+ ret = -EINVAL;
+ goto out_free;
+ }
+
+ /* Get #power-domain-cells from parent */
+ ret = of_property_read_u32(parent_np, "#power-domain-cells", &parent_cells);
+ if (ret) {
+ pr_err("Missing #power-domain-cells in parent %pOF for %pOF\n", parent_np, np);
+ of_node_put(parent_np);
+ goto out_free;
+ }
+
+ /* Build parent_args structure */
+ parent_args.np = parent_np;
+ parent_args.args_count = parent_cells;
+
+ /* Extract parent specifier arguments if any */
+ if (parent_cells > 0) {
+ if (i + parent_cells > map_len) {
+ pr_err("Insufficient parent specifier args in power-domains-map for %pOF\n", np);
+ of_node_put(parent_np);
+ ret = -EINVAL;
+ goto out_free;
+ }
+ memcpy(parent_args.args, &map_entries[i], parent_cells * sizeof(u32));
+ i += parent_cells;
+ }
+
+ /* Validate child ID is within bounds */
+ if (child_id >= data->num_domains) {
+ pr_err("Child ID %u out of bounds (max %u) in power-domains-map for %pOF\n",
+ child_id, data->num_domains - 1, np);
+ of_node_put(parent_np);
+ ret = -EINVAL;
+ goto out_free;
+ }
+
+ /* Get the child domain */
+ child_genpd = data->domains[child_id];
+ if (!child_genpd) {
+ pr_err("Child domain %u is NULL in power-domains-map for %pOF\n", child_id, np);
+ of_node_put(parent_np);
+ ret = -EINVAL;
+ goto out_free;
+ }
+
+ /* Get the parent domain */
+ parent_genpd = genpd_get_from_provider(&parent_args);
+ of_node_put(parent_np);
+ if (IS_ERR(parent_genpd)) {
+ pr_err("Failed to get parent domain for child %u in power-domains-map for %pOF: %ld\n",
+ child_id, np, PTR_ERR(parent_genpd));
+ ret = PTR_ERR(parent_genpd);
+ goto out_free;
+ }
+
+ /* Establish parent-child relationship */
+ ret = genpd_add_subdomain(parent_genpd, child_genpd);
+ if (ret) {
+ pr_err("Failed to add child domain %u to parent in power-domains-map for %pOF: %d\n",
+ child_id, np, ret);
+ goto out_free;
+ }
+
+ pr_debug("Added child domain %u (%s) to parent %s via power-domains-map for %pOF\n",
+ child_id, child_genpd->name, parent_genpd->name, np);
+ }
+
+ ret = 0;
+
+out_free:
+ kfree(map_entries);
+ return ret;
+}
+
/**
* of_genpd_add_device() - Add a device to an I/O PM domain
* @genpdspec: OF phandle args to use for look-up PM domain
Currently, PM domains can only support hierarchy for simple providers (e.g. ones with #power-domain-cells = 0). Add support for oncell providers as well by adding support for a nexus node map, as described in section 2.5.1 of the DT spec. For example, an SCMI PM domain provider might be a subdomain of multiple parent domains. In this example, the parent domains are MAIN_PD and WKUP_PD: scmi_pds: protocol@11 { reg = <0x11>; #power-domain-cells = <1>; power-domain-map = <15 &MAIN_PD>, <19 &WKUP_PD>; }; With the new map, child domain 15 (scmi_pds 15) becomes a subdomain of MAIN_PD, and child domain 19 (scmi_pds 19) becomes a subdomain of WKUP_PD. Signed-off-by: Kevin Hilman <khilman@baylibre.com> --- drivers/pmdomain/core.c | 166 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 166 insertions(+)