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path: root/drivers/clk/clk.c
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Diffstat (limited to 'drivers/clk/clk.c')
-rw-r--r--drivers/clk/clk.c221
1 files changed, 80 insertions, 141 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index b4db67a446c8..fb74dc1f7520 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -350,13 +350,12 @@ static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
{
if (!core || index >= core->num_parents)
return NULL;
- else if (!core->parents)
- return clk_core_lookup(core->parent_names[index]);
- else if (!core->parents[index])
- return core->parents[index] =
- clk_core_lookup(core->parent_names[index]);
- else
- return core->parents[index];
+
+ if (!core->parents[index])
+ core->parents[index] =
+ clk_core_lookup(core->parent_names[index]);
+
+ return core->parents[index];
}
struct clk_hw *
@@ -386,7 +385,7 @@ static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
ret = core->rate;
- if (core->flags & CLK_IS_ROOT)
+ if (!core->num_parents)
goto out;
if (!core->parent)
@@ -1067,30 +1066,12 @@ static int clk_fetch_parent_index(struct clk_core *core,
{
int i;
- if (!core->parents) {
- core->parents = kcalloc(core->num_parents,
- sizeof(struct clk *), GFP_KERNEL);
- if (!core->parents)
- return -ENOMEM;
- }
-
- /*
- * find index of new parent clock using cached parent ptrs,
- * or if not yet cached, use string name comparison and cache
- * them now to avoid future calls to clk_core_lookup.
- */
- for (i = 0; i < core->num_parents; i++) {
- if (core->parents[i] == parent)
- return i;
-
- if (core->parents[i])
- continue;
+ if (!parent)
+ return -EINVAL;
- if (!strcmp(core->parent_names[i], parent->name)) {
- core->parents[i] = clk_core_lookup(parent->name);
+ for (i = 0; i < core->num_parents; i++)
+ if (clk_core_get_parent_by_index(core, i) == parent)
return i;
- }
- }
return -EINVAL;
}
@@ -1677,56 +1658,14 @@ struct clk *clk_get_parent(struct clk *clk)
}
EXPORT_SYMBOL_GPL(clk_get_parent);
-/*
- * .get_parent is mandatory for clocks with multiple possible parents. It is
- * optional for single-parent clocks. Always call .get_parent if it is
- * available and WARN if it is missing for multi-parent clocks.
- *
- * For single-parent clocks without .get_parent, first check to see if the
- * .parents array exists, and if so use it to avoid an expensive tree
- * traversal. If .parents does not exist then walk the tree.
- */
static struct clk_core *__clk_init_parent(struct clk_core *core)
{
- struct clk_core *ret = NULL;
- u8 index;
+ u8 index = 0;
- /* handle the trivial cases */
+ if (core->num_parents > 1 && core->ops->get_parent)
+ index = core->ops->get_parent(core->hw);
- if (!core->num_parents)
- goto out;
-
- if (core->num_parents == 1) {
- if (IS_ERR_OR_NULL(core->parent))
- core->parent = clk_core_lookup(core->parent_names[0]);
- ret = core->parent;
- goto out;
- }
-
- if (!core->ops->get_parent) {
- WARN(!core->ops->get_parent,
- "%s: multi-parent clocks must implement .get_parent\n",
- __func__);
- goto out;
- }
-
- /*
- * Do our best to cache parent clocks in core->parents. This prevents
- * unnecessary and expensive lookups. We don't set core->parent here;
- * that is done by the calling function.
- */
-
- index = core->ops->get_parent(core->hw);
-
- if (!core->parents)
- core->parents =
- kcalloc(core->num_parents, sizeof(struct clk *),
- GFP_KERNEL);
-
- ret = clk_core_get_parent_by_index(core, index);
-
-out:
- return ret;
+ return clk_core_get_parent_by_index(core, index);
}
static void clk_core_reparent(struct clk_core *core,
@@ -1809,13 +1748,13 @@ static int clk_core_set_parent(struct clk_core *core, struct clk_core *parent)
/* try finding the new parent index */
if (parent) {
p_index = clk_fetch_parent_index(core, parent);
- p_rate = parent->rate;
if (p_index < 0) {
pr_debug("%s: clk %s can not be parent of clk %s\n",
__func__, parent->name, core->name);
ret = p_index;
goto out;
}
+ p_rate = parent->rate;
}
/* propagate PRE_RATE_CHANGE notifications */
@@ -1902,6 +1841,10 @@ int clk_set_phase(struct clk *clk, int degrees)
clk_prepare_lock();
+ /* bail early if nothing to do */
+ if (degrees == clk->core->phase)
+ goto out;
+
trace_clk_set_phase(clk->core, degrees);
if (clk->core->ops->set_phase)
@@ -1912,6 +1855,7 @@ int clk_set_phase(struct clk *clk, int degrees)
if (!ret)
clk->core->phase = degrees;
+out:
clk_prepare_unlock();
return ret;
@@ -2218,7 +2162,7 @@ unlock:
*
* Dynamically removes a clk and all its child nodes from the
* debugfs clk directory if clk->dentry points to debugfs created by
- * clk_debug_register in __clk_init.
+ * clk_debug_register in __clk_core_init.
*/
static void clk_debug_unregister(struct clk_core *core)
{
@@ -2303,26 +2247,22 @@ static inline void clk_debug_unregister(struct clk_core *core)
#endif
/**
- * __clk_init - initialize the data structures in a struct clk
- * @dev: device initializing this clk, placeholder for now
- * @clk: clk being initialized
+ * __clk_core_init - initialize the data structures in a struct clk_core
+ * @core: clk_core being initialized
*
* Initializes the lists in struct clk_core, queries the hardware for the
* parent and rate and sets them both.
*/
-static int __clk_init(struct device *dev, struct clk *clk_user)
+static int __clk_core_init(struct clk_core *core)
{
int i, ret = 0;
struct clk_core *orphan;
struct hlist_node *tmp2;
- struct clk_core *core;
unsigned long rate;
- if (!clk_user)
+ if (!core)
return -EINVAL;
- core = clk_user->core;
-
clk_prepare_lock();
/* check to see if a clock with this name is already registered */
@@ -2337,22 +2277,29 @@ static int __clk_init(struct device *dev, struct clk *clk_user)
if (core->ops->set_rate &&
!((core->ops->round_rate || core->ops->determine_rate) &&
core->ops->recalc_rate)) {
- pr_warning("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
- __func__, core->name);
+ pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
+ __func__, core->name);
ret = -EINVAL;
goto out;
}
if (core->ops->set_parent && !core->ops->get_parent) {
- pr_warning("%s: %s must implement .get_parent & .set_parent\n",
- __func__, core->name);
+ pr_err("%s: %s must implement .get_parent & .set_parent\n",
+ __func__, core->name);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (core->num_parents > 1 && !core->ops->get_parent) {
+ pr_err("%s: %s must implement .get_parent as it has multi parents\n",
+ __func__, core->name);
ret = -EINVAL;
goto out;
}
if (core->ops->set_rate_and_parent &&
!(core->ops->set_parent && core->ops->set_rate)) {
- pr_warn("%s: %s must implement .set_parent & .set_rate\n",
+ pr_err("%s: %s must implement .set_parent & .set_rate\n",
__func__, core->name);
ret = -EINVAL;
goto out;
@@ -2364,37 +2311,12 @@ static int __clk_init(struct device *dev, struct clk *clk_user)
"%s: invalid NULL in %s's .parent_names\n",
__func__, core->name);
- /*
- * Allocate an array of struct clk *'s to avoid unnecessary string
- * look-ups of clk's possible parents. This can fail for clocks passed
- * in to clk_init during early boot; thus any access to core->parents[]
- * must always check for a NULL pointer and try to populate it if
- * necessary.
- *
- * If core->parents is not NULL we skip this entire block. This allows
- * for clock drivers to statically initialize core->parents.
- */
- if (core->num_parents > 1 && !core->parents) {
- core->parents = kcalloc(core->num_parents, sizeof(struct clk *),
- GFP_KERNEL);
- /*
- * clk_core_lookup returns NULL for parents that have not been
- * clk_init'd; thus any access to clk->parents[] must check
- * for a NULL pointer. We can always perform lazy lookups for
- * missing parents later on.
- */
- if (core->parents)
- for (i = 0; i < core->num_parents; i++)
- core->parents[i] =
- clk_core_lookup(core->parent_names[i]);
- }
-
core->parent = __clk_init_parent(core);
/*
- * Populate core->parent if parent has already been __clk_init'd. If
- * parent has not yet been __clk_init'd then place clk in the orphan
- * list. If clk has set the CLK_IS_ROOT flag then place it in the root
+ * Populate core->parent if parent has already been clk_core_init'd. If
+ * parent has not yet been clk_core_init'd then place clk in the orphan
+ * list. If clk doesn't have any parents then place it in the root
* clk list.
*
* Every time a new clk is clk_init'd then we walk the list of orphan
@@ -2405,7 +2327,7 @@ static int __clk_init(struct device *dev, struct clk *clk_user)
hlist_add_head(&core->child_node,
&core->parent->children);
core->orphan = core->parent->orphan;
- } else if (core->flags & CLK_IS_ROOT) {
+ } else if (!core->num_parents) {
hlist_add_head(&core->child_node, &clk_root_list);
core->orphan = false;
} else {
@@ -2454,24 +2376,15 @@ static int __clk_init(struct device *dev, struct clk *clk_user)
core->rate = core->req_rate = rate;
/*
- * walk the list of orphan clocks and reparent any that are children of
- * this clock
+ * walk the list of orphan clocks and reparent any that newly finds a
+ * parent.
*/
hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
- if (orphan->num_parents && orphan->ops->get_parent) {
- i = orphan->ops->get_parent(orphan->hw);
- if (i >= 0 && i < orphan->num_parents &&
- !strcmp(core->name, orphan->parent_names[i]))
- clk_core_reparent(orphan, core);
- continue;
- }
+ struct clk_core *parent = __clk_init_parent(orphan);
- for (i = 0; i < orphan->num_parents; i++)
- if (!strcmp(core->name, orphan->parent_names[i])) {
- clk_core_reparent(orphan, core);
- break;
- }
- }
+ if (parent)
+ clk_core_reparent(orphan, parent);
+ }
/*
* optional platform-specific magic
@@ -2585,21 +2498,31 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw)
}
}
+ /* avoid unnecessary string look-ups of clk_core's possible parents. */
+ core->parents = kcalloc(core->num_parents, sizeof(*core->parents),
+ GFP_KERNEL);
+ if (!core->parents) {
+ ret = -ENOMEM;
+ goto fail_parents;
+ };
+
INIT_HLIST_HEAD(&core->clks);
hw->clk = __clk_create_clk(hw, NULL, NULL);
if (IS_ERR(hw->clk)) {
ret = PTR_ERR(hw->clk);
- goto fail_parent_names_copy;
+ goto fail_parents;
}
- ret = __clk_init(dev, hw->clk);
+ ret = __clk_core_init(core);
if (!ret)
return hw->clk;
__clk_free_clk(hw->clk);
hw->clk = NULL;
+fail_parents:
+ kfree(core->parents);
fail_parent_names_copy:
while (--i >= 0)
kfree_const(core->parent_names[i]);
@@ -2683,7 +2606,7 @@ void clk_unregister(struct clk *clk)
if (clk->core->ops == &clk_nodrv_ops) {
pr_err("%s: unregistered clock: %s\n", __func__,
clk->core->name);
- return;
+ goto unlock;
}
/*
* Assign empty clock ops for consumers that might still hold
@@ -2709,7 +2632,7 @@ void clk_unregister(struct clk *clk)
pr_warn("%s: unregistering prepared clock: %s\n",
__func__, clk->core->name);
kref_put(&clk->core->ref, __clk_release);
-
+unlock:
clk_prepare_unlock();
}
EXPORT_SYMBOL_GPL(clk_unregister);
@@ -3061,10 +2984,23 @@ struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
{
return __of_clk_get_from_provider(clkspec, NULL, __func__);
}
+EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
-int of_clk_get_parent_count(struct device_node *np)
+/**
+ * of_clk_get_parent_count() - Count the number of clocks a device node has
+ * @np: device node to count
+ *
+ * Returns: The number of clocks that are possible parents of this node
+ */
+unsigned int of_clk_get_parent_count(struct device_node *np)
{
- return of_count_phandle_with_args(np, "clocks", "#clock-cells");
+ int count;
+
+ count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
+ if (count < 0)
+ return 0;
+
+ return count;
}
EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
@@ -3214,6 +3150,9 @@ void __init of_clk_init(const struct of_device_id *matches)
for_each_matching_node_and_match(np, matches, &match) {
struct clock_provider *parent;
+ if (!of_device_is_available(np))
+ continue;
+
parent = kzalloc(sizeof(*parent), GFP_KERNEL);
if (!parent) {
list_for_each_entry_safe(clk_provider, next,