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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.c111
1 files changed, 79 insertions, 32 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 27c30a533759..c249f9791ae8 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -594,45 +594,59 @@ clk_core_forward_rate_req(struct clk_core *core,
req->max_rate = old_req->max_rate;
}
-int clk_mux_determine_rate_flags(struct clk_hw *hw,
- struct clk_rate_request *req,
- unsigned long flags)
+static int
+clk_core_determine_rate_no_reparent(struct clk_hw *hw,
+ struct clk_rate_request *req)
{
- struct clk_core *core = hw->core, *parent, *best_parent = NULL;
- int i, num_parents, ret;
- unsigned long best = 0;
-
- /* if NO_REPARENT flag set, pass through to current parent */
- if (core->flags & CLK_SET_RATE_NO_REPARENT) {
- parent = core->parent;
- if (core->flags & CLK_SET_RATE_PARENT) {
- struct clk_rate_request parent_req;
+ struct clk_core *core = hw->core;
+ struct clk_core *parent = core->parent;
+ unsigned long best;
+ int ret;
- if (!parent) {
- req->rate = 0;
- return 0;
- }
+ if (core->flags & CLK_SET_RATE_PARENT) {
+ struct clk_rate_request parent_req;
- clk_core_forward_rate_req(core, req, parent, &parent_req, req->rate);
+ if (!parent) {
+ req->rate = 0;
+ return 0;
+ }
- trace_clk_rate_request_start(&parent_req);
+ clk_core_forward_rate_req(core, req, parent, &parent_req,
+ req->rate);
- ret = clk_core_round_rate_nolock(parent, &parent_req);
- if (ret)
- return ret;
+ trace_clk_rate_request_start(&parent_req);
- trace_clk_rate_request_done(&parent_req);
+ ret = clk_core_round_rate_nolock(parent, &parent_req);
+ if (ret)
+ return ret;
- best = parent_req.rate;
- } else if (parent) {
- best = clk_core_get_rate_nolock(parent);
- } else {
- best = clk_core_get_rate_nolock(core);
- }
+ trace_clk_rate_request_done(&parent_req);
- goto out;
+ best = parent_req.rate;
+ } else if (parent) {
+ best = clk_core_get_rate_nolock(parent);
+ } else {
+ best = clk_core_get_rate_nolock(core);
}
+ req->best_parent_rate = best;
+ req->rate = best;
+
+ return 0;
+}
+
+int clk_mux_determine_rate_flags(struct clk_hw *hw,
+ struct clk_rate_request *req,
+ unsigned long flags)
+{
+ struct clk_core *core = hw->core, *parent, *best_parent = NULL;
+ int i, num_parents, ret;
+ unsigned long best = 0;
+
+ /* if NO_REPARENT flag set, pass through to current parent */
+ if (core->flags & CLK_SET_RATE_NO_REPARENT)
+ return clk_core_determine_rate_no_reparent(hw, req);
+
/* find the parent that can provide the fastest rate <= rate */
num_parents = core->num_parents;
for (i = 0; i < num_parents; i++) {
@@ -670,9 +684,7 @@ int clk_mux_determine_rate_flags(struct clk_hw *hw,
if (!best_parent)
return -EINVAL;
-out:
- if (best_parent)
- req->best_parent_hw = best_parent->hw;
+ req->best_parent_hw = best_parent->hw;
req->best_parent_rate = best;
req->rate = best;
@@ -772,6 +784,25 @@ int __clk_mux_determine_rate_closest(struct clk_hw *hw,
}
EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
+/*
+ * clk_hw_determine_rate_no_reparent - clk_ops::determine_rate implementation for a clk that doesn't reparent
+ * @hw: mux type clk to determine rate on
+ * @req: rate request, also used to return preferred frequency
+ *
+ * Helper for finding best parent rate to provide a given frequency.
+ * This can be used directly as a determine_rate callback (e.g. for a
+ * mux), or from a more complex clock that may combine a mux with other
+ * operations.
+ *
+ * Returns: 0 on success, -EERROR value on error
+ */
+int clk_hw_determine_rate_no_reparent(struct clk_hw *hw,
+ struct clk_rate_request *req)
+{
+ return clk_core_determine_rate_no_reparent(hw, req);
+}
+EXPORT_SYMBOL_GPL(clk_hw_determine_rate_no_reparent);
+
/*** clk api ***/
static void clk_core_rate_unprotect(struct clk_core *core)
@@ -1549,6 +1580,7 @@ void clk_hw_forward_rate_request(const struct clk_hw *hw,
parent->core, req,
parent_rate);
}
+EXPORT_SYMBOL_GPL(clk_hw_forward_rate_request);
static bool clk_core_can_round(struct clk_core * const core)
{
@@ -3745,6 +3777,13 @@ static int __clk_core_init(struct clk_core *core)
goto out;
}
+ if (core->ops->set_parent && !core->ops->determine_rate) {
+ pr_err("%s: %s must implement .set_parent & .determine_rate\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);
@@ -4301,11 +4340,18 @@ static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
return -ENXIO;
}
+static int clk_nodrv_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
+{
+ return -ENXIO;
+}
+
static const struct clk_ops clk_nodrv_ops = {
.enable = clk_nodrv_prepare_enable,
.disable = clk_nodrv_disable_unprepare,
.prepare = clk_nodrv_prepare_enable,
.unprepare = clk_nodrv_disable_unprepare,
+ .determine_rate = clk_nodrv_determine_rate,
.set_rate = clk_nodrv_set_rate,
.set_parent = clk_nodrv_set_parent,
};
@@ -4695,6 +4741,7 @@ int devm_clk_notifier_register(struct device *dev, struct clk *clk,
if (!ret) {
devres->clk = clk;
devres->nb = nb;
+ devres_add(dev, devres);
} else {
devres_free(devres);
}