clk: mediatek: cpumux: Implement unregister API

The cpumux clk type within the MediaTek clk driver library only has
a register function, and no corresponding unregister function. This
means there is no way for its users to properly implement cleanup
and removal.

Add a matching unregister function for the cpumux type clk.
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: Miles Chen <miles.chen@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20220208124034.414635-7-wenst@chromium.orgReviewed-by: Chun-Jie Chen <chun-jie.chen@mediatek.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/mediatek/clk-cpumux.c

@@ -77,6 +77,21 @@ mtk_clk_register_cpumux(const struct mtk_composite *mux,
 	return clk;
 }
 
+static void mtk_clk_unregister_cpumux(struct clk *clk)
+{
+	struct mtk_clk_cpumux *cpumux;
+	struct clk_hw *hw;
+
+	hw = __clk_get_hw(clk);
+	if (!hw)
+		return;
+
+	cpumux = to_mtk_clk_cpumux(hw);
+
+	clk_unregister(clk);
+	kfree(cpumux);
+}
+
 int mtk_clk_register_cpumuxes(struct device_node *node,
 			      const struct mtk_composite *clks, int num,
 			      struct clk_onecell_data *clk_data)
@@ -106,4 +121,20 @@ int mtk_clk_register_cpumuxes(struct device_node *node,
 	return 0;
 }
 
+void mtk_clk_unregister_cpumuxes(const struct mtk_composite *clks, int num,
+				 struct clk_onecell_data *clk_data)
+{
+	int i;
+
+	for (i = num; i > 0; i--) {
+		const struct mtk_composite *mux = &clks[i - 1];
+
+		if (IS_ERR_OR_NULL(clk_data->clks[mux->id]))
+			continue;
+
+		mtk_clk_unregister_cpumux(clk_data->clks[mux->id]);
+		clk_data->clks[mux->id] = ERR_PTR(-ENOENT);
+	}
+}
+
 MODULE_LICENSE("GPL");

drivers/clk/mediatek/clk-cpumux.h

@@ -19,4 +19,7 @@ int mtk_clk_register_cpumuxes(struct device_node *node,
 			      const struct mtk_composite *clks, int num,
 			      struct clk_onecell_data *clk_data);
 
+void mtk_clk_unregister_cpumuxes(const struct mtk_composite *clks, int num,
+				 struct clk_onecell_data *clk_data);
+
 #endif /* __DRV_CLK_CPUMUX_H */