clk: core: enforce clk_ops consistency

Documentation/clk.txt has some handsome ASCII art outlining which
clk_ops are mandatory for a given clock, given the capability of the
hardware.  Enforce those mandates with sanity checks in __clk_init.

Signed-off-by: Mike Turquette <mturquette@linaro.org>

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index d83a9e09e1bfcf0f52a25d365da97ae2e1e7c7d4..9924aec17aad7043ccbe265b5c22cb512ceea74f 100644 (file)
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1202,6 +1202,20 @@ void __clk_init(struct device *dev, struct clk *clk)
        if (__clk_lookup(clk->name))
                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);
+               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);
+               goto out;
+       }
+
        /* throw a WARN if any entries in parent_names are NULL */
        for (i = 0; i < clk->num_parents; i++)
                WARN(!clk->parent_names[i],