late_initcall(clk_debug_init);
#else
static inline int clk_debug_register(struct clk *clk) { return 0; }
-#endif /* CONFIG_COMMON_CLK_DEBUG */
+#endif
#ifdef CONFIG_COMMON_CLK_DISABLE_UNUSED
/* caller must hold prepare_lock */
return 0;
}
late_initcall(clk_disable_unused);
-#else
-static inline int clk_disable_unused(struct clk *clk) { return 0; }
-#endif /* CONFIG_COMMON_CLK_DISABLE_UNUSED */
+#endif
/*** helper functions ***/
unsigned long ret;
if (!clk) {
- ret = -EINVAL;
+ ret = 0;
goto out;
}
goto out;
if (!clk->parent)
- ret = -ENODEV;
+ ret = 0;
out:
return ret;
* @clk: the clk whose rate is being returned
*
* Simply returns the cached rate of the clk. Does not query the hardware. If
- * clk is NULL then returns -EINVAL.
+ * clk is NULL then returns 0.
*/
unsigned long clk_get_rate(struct clk *clk)
{
static struct clk *clk_calc_new_rates(struct clk *clk, unsigned long rate)
{
struct clk *top = clk;
- unsigned long best_parent_rate = clk->parent->rate;
+ unsigned long best_parent_rate;
unsigned long new_rate;
- if (!clk->ops->round_rate && !(clk->flags & CLK_SET_RATE_PARENT)) {
- clk->new_rate = clk->rate;
+ /* sanity */
+ if (IS_ERR_OR_NULL(clk))
return NULL;
+
+ /* never propagate up to the parent */
+ if (!(clk->flags & CLK_SET_RATE_PARENT)) {
+ if (!clk->ops->round_rate) {
+ clk->new_rate = clk->rate;
+ return NULL;
+ } else {
+ new_rate = clk->ops->round_rate(clk->hw, rate, NULL);
+ goto out;
+ }
}
- if (!clk->ops->round_rate && (clk->flags & CLK_SET_RATE_PARENT)) {
+ /* need clk->parent from here on out */
+ if (!clk->parent) {
+ pr_debug("%s: %s has NULL parent\n", __func__, clk->name);
+ return NULL;
+ }
+
+ if (!clk->ops->round_rate) {
top = clk_calc_new_rates(clk->parent, rate);
new_rate = clk->new_rate = clk->parent->new_rate;
goto out;
}
- if (clk->flags & CLK_SET_RATE_PARENT)
- new_rate = clk->ops->round_rate(clk->hw, rate, &best_parent_rate);
- else
- new_rate = clk->ops->round_rate(clk->hw, rate, NULL);
+ new_rate = clk->ops->round_rate(clk->hw, rate, &best_parent_rate);
if (best_parent_rate != clk->parent->rate) {
top = clk_calc_new_rates(clk->parent, best_parent_rate);
* @clk: the clk whose rate is being changed
* @rate: the new rate for clk
*
- * In the simplest case clk_set_rate will only change the rate of clk.
- *
- * If clk has the CLK_SET_RATE_GATE flag set and it is enabled this call
- * will fail; only when the clk is disabled will it be able to change
- * its rate.
- *
- * Setting the CLK_SET_RATE_PARENT flag allows clk_set_rate to
- * recursively propagate up to clk's parent; whether or not this happens
- * depends on the outcome of clk's .round_rate implementation. If
- * *parent_rate is 0 after calling .round_rate then upstream parent
- * propagation is ignored. If *parent_rate comes back with a new rate
- * for clk's parent then we propagate up to clk's parent and set it's
- * rate. Upward propagation will continue until either a clk does not
- * support the CLK_SET_RATE_PARENT flag or .round_rate stops requesting
- * changes to clk's parent_rate. If there is a failure during upstream
- * propagation then clk_set_rate will unwind and restore each clk's rate
- * that had been successfully changed. Afterwards a rate change abort
- * notification will be propagated downstream, starting from the clk
- * that failed.
+ * In the simplest case clk_set_rate will only adjust the rate of clk.
*
- * At the end of all of the rate setting, clk_set_rate internally calls
- * __clk_recalc_rates and propagates the rate changes downstream,
- * starting from the highest clk whose rate was changed. This has the
- * added benefit of propagating post-rate change notifiers.
+ * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
+ * propagate up to clk's parent; whether or not this happens depends on the
+ * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
+ * after calling .round_rate then upstream parent propagation is ignored. If
+ * *parent_rate comes back with a new rate for clk's parent then we propagate
+ * up to clk's parent and set it's rate. Upward propagation will continue
+ * until either a clk does not support the CLK_SET_RATE_PARENT flag or
+ * .round_rate stops requesting changes to clk's parent_rate.
*
- * Note that while post-rate change and rate change abort notifications
- * are guaranteed to be sent to a clk only once per call to
- * clk_set_rate, pre-change notifications will be sent for every clk
- * whose rate is changed. Stacking pre-change notifications is noisy
- * for the drivers subscribed to them, but this allows drivers to react
- * to intermediate clk rate changes up until the point where the final
- * rate is achieved at the end of upstream propagation.
+ * Rate changes are accomplished via tree traversal that also recalculates the
+ * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
*
* Returns 0 on success, -EERROR otherwise.
*/
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],
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