[PATCH v2 2/2] of: changesets: Introduce changeset helper methods

From: Pantelis Antoniou
Date: Wed Sep 16 2015 - 12:12:01 EST


Changesets are very powerful, but the lack of a helper API
makes using them cumbersome. Introduce a simple copy based
API that makes things considerably easier.

To wit, adding a property using the raw API.

struct property *prop;
prop = kzalloc(sizeof(*prop)), GFP_KERNEL);
prop->name = kstrdup("compatible");
prop->value = kstrdup("foo,bar");
prop->length = strlen(prop->value) + 1;
of_changeset_add_property(ocs, np, prop);

while using the helper API

of_changeset_add_property_string(ocs, np, "compatible",
"foo,bar");

Signed-off-by: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
---
drivers/of/dynamic.c | 251 +++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/of.h | 74 +++++++++++++++
2 files changed, 325 insertions(+)

diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index e452171..afa8e31 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -796,3 +796,254 @@ int of_changeset_action(struct of_changeset *ocs, unsigned long action,
list_add_tail(&ce->node, &ocs->entries);
return 0;
}
+
+/* changeset helpers */
+
+/**
+ * of_changeset_create_device_node - Create an empty device node
+ *
+ * @ocs: changeset pointer
+ * @parent: parent device node
+ * @fmt: format string for the node's full_name
+ * @args: argument list for the format string
+ *
+ * Create an empty device node, marking it as detached and allocated.
+ *
+ * Returns a device node on success, an error encoded pointer otherwise
+ */
+struct device_node *of_changeset_create_device_nodev(
+ struct of_changeset *ocs, struct device_node *parent,
+ const char *fmt, va_list vargs)
+{
+ struct device_node *node;
+
+ node = __of_node_dupv(NULL, fmt, vargs);
+ if (!node)
+ return ERR_PTR(-ENOMEM);
+
+ node->parent = parent;
+ return node;
+}
+
+/**
+ * of_changeset_create_device_node - Create an empty device node
+ *
+ * @ocs: changeset pointer
+ * @parent: parent device node
+ * @fmt: Format string for the node's full_name
+ * ... Arguments
+ *
+ * Create an empty device node, marking it as detached and allocated.
+ *
+ * Returns a device node on success, an error encoded pointer otherwise
+ */
+struct device_node *of_changeset_create_device_node(
+ struct of_changeset *ocs, struct device_node *parent,
+ const char *fmt, ...)
+{
+ va_list vargs;
+ struct device_node *node;
+
+ va_start(vargs, fmt);
+ node = of_changeset_create_device_nodev(ocs, parent, fmt, vargs);
+ va_end(vargs);
+ return node;
+}
+
+/**
+ * of_changeset_add_property_copy - Create a new property copying name & value
+ *
+ * @ocs: changeset pointer
+ * @np: device node pointer
+ * @name: name of the property
+ * @value: pointer to the value data
+ * @length: length of the value in bytes
+ *
+ * Adds a property to the changeset by making copies of the name & value
+ * entries.
+ *
+ * Returns zero on success, a negative error value otherwise.
+ */
+int of_changeset_add_property_copy(struct of_changeset *ocs,
+ struct device_node *np, const char *name, const void *value,
+ int length)
+{
+ struct property *prop;
+ char *new_name;
+ void *new_value;
+ int ret;
+
+ ret = -ENOMEM;
+
+ prop = kzalloc(sizeof(*prop), GFP_KERNEL);
+ if (!prop)
+ goto out_no_prop;
+
+ new_name = kstrdup(name, GFP_KERNEL);
+ if (!new_name)
+ goto out_no_name;
+
+ /*
+ * NOTE: There is no check for zero length value.
+ * In case of a boolean property, this will allocate a value
+ * of zero bytes. We do this to work around the use
+ * of of_get_property() calls on boolean values.
+ */
+ new_value = kmemdup(value, length, GFP_KERNEL);
+ if (!new_value)
+ goto out_no_value;
+
+ of_property_set_flag(prop, OF_DYNAMIC);
+
+ prop->name = new_name;
+ prop->value = new_value;
+ prop->length = length;
+
+ ret = of_changeset_add_property(ocs, np, prop);
+ if (ret != 0)
+ goto out_no_add;
+
+ return 0;
+
+out_no_add:
+ kfree(prop->value);
+out_no_value:
+ kfree(prop->name);
+out_no_name:
+ kfree(prop);
+out_no_prop:
+ return ret;
+}
+
+/**
+ * of_changeset_add_property_string - Create a new string property
+ *
+ * @ocs: changeset pointer
+ * @np: device node pointer
+ * @name: name of the property
+ * @str: string property
+ *
+ * Adds a string property to the changeset by making copies of the name
+ * and the string value.
+ *
+ * Returns zero on success, a negative error value otherwise.
+ */
+int of_changeset_add_property_string(struct of_changeset *ocs,
+ struct device_node *np, const char *name, const char *str)
+{
+ return of_changeset_add_property_copy(ocs, np, name, str,
+ strlen(str) + 1);
+}
+
+/**
+ * of_changeset_add_property_stringf - Create a new formatted string property
+ *
+ * @ocs: changeset pointer
+ * @np: device node pointer
+ * @name: name of the property
+ * @fmt: format of string property
+ * ... arguments of the format string
+ *
+ * Adds a string property to the changeset by making copies of the name
+ * and the formatted value.
+ *
+ * Returns zero on success, a negative error value otherwise.
+ */
+int of_changeset_add_property_stringf(struct of_changeset *ocs,
+ struct device_node *np, const char *name, const char *fmt, ...)
+{
+ va_list vargs;
+ char *str;
+ int ret;
+
+ va_start(vargs, fmt);
+ str = kvasprintf(GFP_KERNEL, fmt, vargs);
+ va_end(vargs);
+
+ ret = of_changeset_add_property_string(ocs, np, name, str);
+
+ kfree(str);
+ return ret;
+}
+
+/**
+ * of_changeset_add_property_string_list - Create a new string list property
+ *
+ * @ocs: changeset pointer
+ * @np: device node pointer
+ * @name: name of the property
+ * @strs: pointer to the string list
+ * @count: string count
+ *
+ * Adds a string list property to the changeset.
+ *
+ * Returns zero on success, a negative error value otherwise.
+ */
+int of_changeset_add_property_string_list(struct of_changeset *ocs,
+ struct device_node *np, const char *name, const char **strs,
+ int count)
+{
+ int total, length, i, ret;
+ char *value, *s;
+
+ total = 0;
+ for (i = 0; i < count; i++) {
+ length = strlen(strs[i]);
+ total += length + 1;
+ }
+
+ value = kmalloc(total, GFP_KERNEL);
+ if (!value)
+ return -ENOMEM;
+
+ for (i = 0, s = value; i < count; i++) {
+ length = strlen(strs[i]);
+ memcpy(s, strs[i], length + 1);
+ s += length + 1;
+ }
+
+ ret = of_changeset_add_property_copy(ocs, np, name, value, total);
+
+ kfree(value);
+
+ return ret;
+}
+
+/**
+ * of_changeset_add_property_u32 - Create a new u32 property
+ *
+ * @ocs: changeset pointer
+ * @np: device node pointer
+ * @name: name of the property
+ * @val: value in host endian format
+ *
+ * Adds a u32 property to the changeset.
+ *
+ * Returns zero on success, a negative error value otherwise.
+ */
+int of_changeset_add_property_u32(struct of_changeset *ocs,
+ struct device_node *np, const char *name, u32 val)
+{
+ /* in place */
+ val = cpu_to_be32(val);
+ return of_changeset_add_property_copy(ocs, np, name, &val, sizeof(val));
+}
+
+/**
+ * of_changeset_add_property_bool - Create a new u32 property
+ *
+ * @ocs: changeset pointer
+ * @np: device node pointer
+ * @name: name of the property
+ *
+ * Adds a bool property to the changeset. Note that there is
+ * no option to set the value to false, since the property
+ * existing sets it to true.
+ *
+ * Returns zero on success, a negative error value otherwise.
+ */
+int of_changeset_add_property_bool(struct of_changeset *ocs,
+ struct device_node *np, const char *name)
+{
+ return of_changeset_add_property_copy(ocs, np, name, "", 0);
+}
diff --git a/include/linux/of.h b/include/linux/of.h
index b0856ed..1e6019a 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -1037,6 +1037,27 @@ 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_device_nodev(
+ struct of_changeset *ocs, struct device_node *parent,
+ const char *fmt, va_list vargs);
+__printf(3, 4) struct device_node *of_changeset_create_device_node(
+ struct of_changeset *ocs, struct device_node *parent,
+ const char *fmt, ...);
+int of_changeset_add_property_copy(struct of_changeset *ocs,
+ struct device_node *np, const char *name,
+ const void *value, int length);
+int of_changeset_add_property_string(struct of_changeset *ocs,
+ struct device_node *np, const char *name, const char *str);
+__printf(4, 5) int of_changeset_add_property_stringf(struct of_changeset *ocs,
+ struct device_node *np, const char *name, const char *fmt, ...);
+int of_changeset_add_property_string_list(struct of_changeset *ocs,
+ struct device_node *np, const char *name, const char **strs, int count);
+int of_changeset_add_property_u32(struct of_changeset *ocs,
+ struct device_node *np, const char *name, u32 val);
+int of_changeset_add_property_bool(struct of_changeset *ocs,
+ struct device_node *np, const char *name);
+
#else /* CONFIG_OF_DYNAMIC */
static inline int of_reconfig_notifier_register(struct notifier_block *nb)
{
@@ -1056,6 +1077,59 @@ static inline int of_reconfig_get_state_change(unsigned long action,
{
return -EINVAL;
}
+
+static inline int of_changeset_create_device_node(struct of_changeset *ocs,
+ struct device_node *parent, const char *fmt, ...)
+{
+ return -EINVAL;
+}
+
+int of_changeset_add_property_copy(struct of_changeset *ocs,
+ struct device_node *np, const char *name,
+ const void *value, int length)
+{
+ return -EINVAL;
+}
+
+int of_changeset_add_property_string(struct of_changeset *ocs,
+ struct device_node *np, const char *name, const char *str)
+{
+ return -EINVAL;
+}
+
+static inline struct device_node *of_changeset_create_device_nodev(
+ struct of_changeset *ocs, struct device_node *parent,
+ const char *fmt, va_list vargs)
+{
+ return ERR_PTR(-EINVAL);
+}
+
+static inline __printf(4, 5) struct device_node *
+ of_changeset_add_property_stringf(
+ struct of_changeset *ocs, struct device_node *np,
+ const char *name, const char *fmt, ...)
+{
+ return ERR_PTR(-EINVAL);
+}
+
+static inline int of_changeset_add_property_string_list(
+ struct of_changeset *ocs, struct device_node *np, const char *name,
+ const char **strs, int count)
+{
+ return -EINVAL;
+}
+
+static inline int of_changeset_add_property_u32(struct of_changeset *ocs,
+ struct device_node *np, const char *name, u32 val)
+{
+ return -EINVAL;
+}
+
+static inline int of_changeset_add_property_bool(struct of_changeset *ocs,
+ struct device_node *np, const char *name)
+{
+ return -EINVAL;
+}
#endif /* CONFIG_OF_DYNAMIC */

/* CONFIG_OF_RESOLVE api */
--
1.7.12

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