Pass the unmapped parent ID when setting parent for mux clocks.
For technical reasons, some Mediatek clock driver have a mapping between
the clock IDs used in the devicetree and ID used in the generic clock
framework.
The mtk_clk_mux_set_parent() function is comparing the passed mapped
parent ID against the unmapped IDs in the chip-specific data structures.
Before this change, we were passing the mapped parent ID. When there is
a mapping, this resulted in buggy behavior (usually just incorrectly
failing to find a match and returning an error). We need to pass the
unmapped ID of the parent clock instead for the matching to work
correctly.
Since the reverse lookup is a bit verbose, a helper function is added to
keep the code clean.
Fixes: b1358915728b ("clk: mediatek: add of_xlate ops")
Signed-off-by: David Lechner <[email protected]>
---
drivers/clk/mediatek/clk-mtk.c | 25 ++++++++++++++++++++++++-
1 file changed, 24 insertions(+), 1 deletion(-)
diff --git a/drivers/clk/mediatek/clk-mtk.c b/drivers/clk/mediatek/clk-mtk.c
index 82306ae285c..acc28d1da1a 100644
--- a/drivers/clk/mediatek/clk-mtk.c
+++ b/drivers/clk/mediatek/clk-mtk.c
@@ -66,6 +66,24 @@ static const int mtk_common_clk_of_xlate(struct clk *clk,
return 0;
}
+static int mtk_common_clk_get_unmapped_id(struct clk *clk)
+{
+ struct mtk_clk_priv *priv = dev_get_priv(clk->dev);
+ const struct mtk_clk_tree *tree = priv->tree;
+ int i;
+
+ if (!tree->id_offs_map)
+ return clk->id;
+
+ /* Perform reverse lookup of unmapped ID. */
+ for (i = 0; i < tree->id_offs_map_size; i++) {
+ if (tree->id_offs_map[i] == clk->id)
+ return i;
+ }
+
+ return -ENOENT;
+}
+
static int mtk_dummy_enable(struct clk *clk)
{
return 0;
@@ -812,6 +830,7 @@ static int mtk_common_clk_set_parent(struct clk *clk,
struct clk *parent)
{
struct mtk_clk_priv *parent_priv = dev_get_priv(parent->dev);
struct mtk_clk_priv *priv = dev_get_priv(clk->dev);
+ int parent_unmapped_id;
u32 parent_type;
if (!priv->tree->muxes || clk->id < priv->tree->muxes_offs ||
@@ -821,8 +840,12 @@ static int mtk_common_clk_set_parent(struct clk *clk,
struct clk *parent)
if (!parent_priv)
return 0;
+ parent_unmapped_id = mtk_common_clk_get_unmapped_id(parent);
+ if (parent_unmapped_id < 0)
+ return parent_unmapped_id;
+
parent_type = parent_priv->tree->flags & CLK_PARENT_MASK;
- return mtk_clk_mux_set_parent(priv->base, parent->id, parent_type,
+ return mtk_clk_mux_set_parent(priv->base, parent_unmapped_id,
parent_type,
&priv->tree->muxes[clk->id - priv->tree->muxes_offs]);
}
---
base-commit: d503633a36767d756c7de28305cf0de79440cbc0
change-id: 20260114-clk-mtk-fix-mux-set-parent-497d033dc721
Best regards,
--
David Lechner <[email protected]>
