From c196b0a6882929bf0b6504eae963f24289ee5d85 Mon Sep 17 00:00:00 2001 From: David Lechner Date: Wed, 14 Jan 2026 16:24:14 -0600 Subject: [PATCH] clk: mediatek: fix mux clocks with mapped parent IDs 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 --- 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]); }