[PATCH V12 1/5] of: dynamic: Add interfaces for creating device node dynamically

Lizhi Hou
2023-07-28T17:07:20Z

of_changeset_create_node() creates device node dynamically and attaches
the newly created node to a changeset.

Expand of_changeset APIs to handle specific types of properties.
of_changeset_add_prop_string()
of_changeset_add_prop_string_array()
of_changeset_add_prop_u32_array()

Signed-off-by: Clément Léger <clement.leger@bootlin.com>
Signed-off-by: Lizhi Hou <lizhi.hou@amd.com>
---
drivers/of/dynamic.c | 164 ++++++++++++++++++++++++++++++++++++++++++
drivers/of/unittest.c | 19 ++++-
include/linux/of.h | 23 ++++++
3 files changed, 205 insertions(+), 1 deletion(-)

diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index e311d406b170..9259cebda4d6 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -487,6 +487,38 @@ struct device_node *__of_node_dup(const struct device_node *np,
return NULL;
}

+/**
+ * of_changeset_create_node - Dynamically create a device node and attach to
+ * a given changeset.
+ *
+ * @parent: Pointer to parent device node
+ * @full_name: Node full name
+ * @cset: Pointer to changeset
+ *
+ * Return: Pointer to the created device node or NULL in case of an error.
+ */
+struct device_node *of_changeset_create_node(struct device_node *parent,
+ const char *full_name,
+ struct of_changeset *cset)
+{
+ struct device_node *np;
+ int ret;
+
+ np = __of_node_dup(NULL, full_name);
+ if (!np)
+ return NULL;
+ np->parent = parent;
+
+ ret = of_changeset_attach_node(cset, np);
+ if (ret) {
+ of_node_put(np);
+ return NULL;
+ }
+
+ return np;
+}
+EXPORT_SYMBOL(of_changeset_create_node);
+
static void __of_changeset_entry_destroy(struct of_changeset_entry *ce)
{
if (ce->action == OF_RECONFIG_ATTACH_NODE &&
@@ -960,3 +992,135 @@ int of_changeset_action(struct of_changeset *ocs, unsigned long action,
return 0;
}
EXPORT_SYMBOL_GPL(of_changeset_action);
+
+static int of_changeset_add_prop_helper(struct of_changeset *ocs,
+ struct device_node *np,
+ const struct property *pp)
+{
+ struct property *new_pp;
+ int ret;
+
+ new_pp = __of_prop_dup(pp, GFP_KERNEL);
+ if (!new_pp)
+ return -ENOMEM;
+
+ ret = of_changeset_add_property(ocs, np, new_pp);
+ if (ret) {
+ kfree(new_pp->name);
+ kfree(new_pp->value);
+ kfree(new_pp);
+ }
+
+ return ret;
+}
+
+/**
+ * of_changeset_add_prop_string - Add a string property to a changeset
+ *
+ * @ocs: changeset pointer
+ * @np: device node pointer
+ * @prop_name: name of the property to be added
+ * @str: pointer to null terminated string
+ *
+ * Create a string property and add it to a changeset.
+ *
+ * Return: 0 on success, a negative error value in case of an error.
+ */
+int of_changeset_add_prop_string(struct of_changeset *ocs,
+ struct device_node *np,
+ const char *prop_name, const char *str)
+{
+ struct property prop;
+
+ prop.name = (char *)prop_name;
+ prop.length = strlen(str) + 1;
+ prop.value = (void *)str;
+
+ return of_changeset_add_prop_helper(ocs, np, &prop);
+}
+EXPORT_SYMBOL_GPL(of_changeset_add_prop_string);
+
+/**
+ * of_changeset_add_prop_string_array - Add a string list property to
+ * a changeset
+ *
+ * @ocs: changeset pointer
+ * @np: device node pointer
+ * @prop_name: name of the property to be added
+ * @str_array: pointer to an array of null terminated strings
+ * @sz: number of string array elements
+ *
+ * Create a string list property and add it to a changeset.
+ *
+ * Return: 0 on success, a negative error value in case of an error.
+ */
+int of_changeset_add_prop_string_array(struct of_changeset *ocs,
+ struct device_node *np,
+ const char *prop_name,
+ const char **str_array, size_t sz)
+{
+ struct property prop;
+ int i, ret;
+ char *vp;
+
+ prop.name = (char *)prop_name;
+
+ prop.length = 0;
+ for (i = 0; i < sz; i++)
+ prop.length += strlen(str_array[i]) + 1;
+
+ prop.value = kmalloc(prop.length, GFP_KERNEL);
+ if (!prop.value)
+ return -ENOMEM;
+
+ vp = prop.value;
+ for (i = 0; i < sz; i++) {
+ vp += snprintf(vp, (char *)prop.value + prop.length - vp, "%s",
+ str_array[i]) + 1;
+ }
+ ret = of_changeset_add_prop_helper(ocs, np, &prop);
+ kfree(prop.value);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(of_changeset_add_prop_string_array);
+
+/**
+ * of_changeset_add_prop_u32_array - Add a property of 32 bit integers
+ * property to a changeset
+ *
+ * @ocs: changeset pointer
+ * @np: device node pointer
+ * @prop_name: name of the property to be added
+ * @array: pointer to an array of 32 bit integers
+ * @sz: number of array elements
+ *
+ * Create a property of 32 bit integers and add it to a changeset.
+ *
+ * Return: 0 on success, a negative error value in case of an error.
+ */
+int of_changeset_add_prop_u32_array(struct of_changeset *ocs,
+ struct device_node *np,
+ const char *prop_name,
+ const u32 *array, size_t sz)
+{
+ struct property prop;
+ __be32 *val;
+ int i, ret;
+
+ val = kcalloc(sz, sizeof(__be32), GFP_KERNEL);
+ if (!val)
+ return -ENOMEM;
+
+ for (i = 0; i < sz; i++)
+ val[i] = cpu_to_be32(array[i]);
+ prop.name = (char *)prop_name;
+ prop.length = sizeof(u32) * sz;
+ prop.value = (void *)val;
+
+ ret = of_changeset_add_prop_helper(ocs, np, &prop);
+ kfree(val);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(of_changeset_add_prop_u32_array);
diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
index a406a12eb208..d2b286d32db0 100644
--- a/drivers/of/unittest.c
+++ b/drivers/of/unittest.c
@@ -802,7 +802,9 @@ static void __init of_unittest_changeset(void)
struct property *ppname_n21, pname_n21 = { .name = "name", .length = 3, .value = "n21" };
struct property *ppupdate, pupdate = { .name = "prop-update", .length = 5, .value = "abcd" };
struct property *ppremove;
- struct device_node *n1, *n2, *n21, *nchangeset, *nremove, *parent, *np;
+ struct device_node *n1, *n2, *n21, *n22, *nchangeset, *nremove, *parent, *np;
+ static const char * const str_array[] = { "str1", "str2", "str3" };
+ const u32 u32_array[] = { 1, 2, 3 };
struct of_changeset chgset;

n1 = __of_node_dup(NULL, "n1");
@@ -857,6 +859,17 @@ static void __init of_unittest_changeset(void)
unittest(!of_changeset_add_property(&chgset, parent, ppadd), "fail add prop prop-add\n");
unittest(!of_changeset_update_property(&chgset, parent, ppupdate), "fail update prop\n");
unittest(!of_changeset_remove_property(&chgset, parent, ppremove), "fail remove prop\n");
+ n22 = of_changeset_create_node(n2, "n22", &chgset);
+ unittest(n22, "fail create n22\n");
+ unittest(!of_changeset_add_prop_string(&chgset, n22, "prop-str", "abcd"),
+ "fail add prop prop-str");
+ unittest(!of_changeset_add_prop_string_array(&chgset, n22, "prop-str-array",
+ (const char **)str_array,
+ ARRAY_SIZE(str_array)),
+ "fail add prop prop-str-array");
+ unittest(!of_changeset_add_prop_u32_array(&chgset, n22, "prop-u32-array",
+ u32_array, ARRAY_SIZE(u32_array)),
+ "fail add prop prop-u32-array");

unittest(!of_changeset_apply(&chgset), "apply failed\n");

@@ -866,6 +879,9 @@ static void __init of_unittest_changeset(void)
unittest((np = of_find_node_by_path("/testcase-data/changeset/n2/n21")),
"'%pOF' not added\n", n21);
of_node_put(np);
+ unittest((np = of_find_node_by_path("/testcase-data/changeset/n2/n22")),
+ "'%pOF' not added\n", n22);
+ of_node_put(np);

unittest(!of_changeset_revert(&chgset), "revert failed\n");

@@ -874,6 +890,7 @@ static void __init of_unittest_changeset(void)
of_node_put(n1);
of_node_put(n2);
of_node_put(n21);
+ of_node_put(n22);
#endif
}

diff --git a/include/linux/of.h b/include/linux/of.h
index 6ecde0515677..82d0a476ec75 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -1580,6 +1580,29 @@ static inline int of_changeset_update_property(struct of_changeset *ocs,
{
return of_changeset_action(ocs, OF_RECONFIG_UPDATE_PROPERTY, np, prop);
}
+
+struct device_node *of_changeset_create_node(struct device_node *parent,
+ const char *full_name,
+ struct of_changeset *cset);
+int of_changeset_add_prop_string(struct of_changeset *ocs,
+ struct device_node *np,
+ const char *prop_name, const char *str);
+int of_changeset_add_prop_string_array(struct of_changeset *ocs,
+ struct device_node *np,
+ const char *prop_name,
+ const char **str_array, size_t sz);
+int of_changeset_add_prop_u32_array(struct of_changeset *ocs,
+ struct device_node *np,
+ const char *prop_name,
+ const u32 *array, size_t sz);
+static inline int of_changeset_add_prop_u32(struct of_changeset *ocs,
+ struct device_node *np,
+ const char *prop_name,
+ const u32 val)
+{
+ return of_changeset_add_prop_u32_array(ocs, np, prop_name, &val, 1);
+}
+
#else /* CONFIG_OF_DYNAMIC */
static inline int of_reconfig_notifier_register(struct notifier_block *nb)
{
--
2.34.1