clk: core: copy parent_names & return error codes
This patch cleans up clk_register and solves a few bugs by teaching
clk_register and __clk_init to return error codes (instead of just NULL)
to better align with the existing clk.h api.
Along with that change this patch also introduces a new behavior whereby
clk_register copies the parent_names array, thus allowing platforms to
declare their parent_names arrays as __initdata.
Signed-off-by: Mike Turquette <mturquette@linaro.org>
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index ddade87..8f7c384 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1185,34 +1185,41 @@
* very large numbers of clocks that need to be statically initialized. It is
* a layering violation to include clk-private.h from any code which implements
* a clock's .ops; as such any statically initialized clock data MUST be in a
- * separate C file from the logic that implements it's operations.
+ * separate C file from the logic that implements it's operations. Returns 0
+ * on success, otherwise an error code.
*/
-void __clk_init(struct device *dev, struct clk *clk)
+int __clk_init(struct device *dev, struct clk *clk)
{
- int i;
+ int i, ret = 0;
struct clk *orphan;
struct hlist_node *tmp, *tmp2;
if (!clk)
- return;
+ return -EINVAL;
mutex_lock(&prepare_lock);
/* check to see if a clock with this name is already registered */
- if (__clk_lookup(clk->name))
+ if (__clk_lookup(clk->name)) {
+ pr_debug("%s: clk %s already initialized\n",
+ __func__, clk->name);
+ ret = -EEXIST;
goto out;
+ }
/* check that clk_ops are sane. See Documentation/clk.txt */
if (clk->ops->set_rate &&
!(clk->ops->round_rate && clk->ops->recalc_rate)) {
pr_warning("%s: %s must implement .round_rate & .recalc_rate\n",
__func__, clk->name);
+ ret = -EINVAL;
goto out;
}
if (clk->ops->set_parent && !clk->ops->get_parent) {
pr_warning("%s: %s must implement .get_parent & .set_parent\n",
__func__, clk->name);
+ ret = -EINVAL;
goto out;
}
@@ -1308,7 +1315,7 @@
out:
mutex_unlock(&prepare_lock);
- return;
+ return ret;
}
/**
@@ -1324,29 +1331,63 @@
* clk_register is the primary interface for populating the clock tree with new
* clock nodes. It returns a pointer to the newly allocated struct clk which
* cannot be dereferenced by driver code but may be used in conjuction with the
- * rest of the clock API.
+ * rest of the clock API. In the event of an error clk_register will return an
+ * error code; drivers must test for an error code after calling clk_register.
*/
struct clk *clk_register(struct device *dev, const char *name,
const struct clk_ops *ops, struct clk_hw *hw,
const char **parent_names, u8 num_parents, unsigned long flags)
{
+ int i, ret;
struct clk *clk;
clk = kzalloc(sizeof(*clk), GFP_KERNEL);
- if (!clk)
- return NULL;
+ if (!clk) {
+ pr_err("%s: could not allocate clk\n", __func__);
+ ret = -ENOMEM;
+ goto fail_out;
+ }
clk->name = name;
clk->ops = ops;
clk->hw = hw;
clk->flags = flags;
- clk->parent_names = parent_names;
clk->num_parents = num_parents;
hw->clk = clk;
- __clk_init(dev, clk);
+ /* allocate local copy in case parent_names is __initdata */
+ clk->parent_names = kzalloc((sizeof(char*) * num_parents),
+ GFP_KERNEL);
- return clk;
+ if (!clk->parent_names) {
+ pr_err("%s: could not allocate clk->parent_names\n", __func__);
+ ret = -ENOMEM;
+ goto fail_parent_names;
+ }
+
+
+ /* copy each string name in case parent_names is __initdata */
+ for (i = 0; i < num_parents; i++) {
+ clk->parent_names[i] = kstrdup(parent_names[i], GFP_KERNEL);
+ if (!clk->parent_names[i]) {
+ pr_err("%s: could not copy parent_names\n", __func__);
+ ret = -ENOMEM;
+ goto fail_parent_names_copy;
+ }
+ }
+
+ ret = __clk_init(dev, clk);
+ if (!ret)
+ return clk;
+
+fail_parent_names_copy:
+ while (--i >= 0)
+ kfree(clk->parent_names[i]);
+ kfree(clk->parent_names);
+fail_parent_names:
+ kfree(clk);
+fail_out:
+ return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(clk_register);
