clk: mediatek: Implement mtk_clk_unregister_divider_clks() API

mtk_clk_register_divider_clks(), as the name suggests, is used to register
a given list of divider clks. However it is lacking a counterpart
unregister API.

Implement said unregister API so that the various clock platform drivers
can utilize it to do proper unregistration, cleanup and removal.

In the header file, the register function's declaration is also
reformatted to fit code style guidelines.

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/20220208124034.414635-18-wenst@chromium.org
Reviewed-by: Chun-Jie Chen <chun-jie.chen@mediatek.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

Author: wens

drivers/clk/mediatek/clk-mtk.c

@@ -286,6 +286,25 @@ void mtk_clk_register_dividers(const struct mtk_clk_divider *mcds,
 	}
 }
 
+void mtk_clk_unregister_dividers(const struct mtk_clk_divider *mcds, int num,
+				 struct clk_onecell_data *clk_data)
+{
+	int i;
+
+	if (!clk_data)
+		return;
+
+	for (i = num; i > 0; i--) {
+		const struct mtk_clk_divider *mcd = &mcds[i - 1];
+
+		if (IS_ERR_OR_NULL(clk_data->clks[mcd->id]))
+			continue;
+
+		clk_unregister_divider(clk_data->clks[mcd->id]);
+		clk_data->clks[mcd->id] = ERR_PTR(-ENOENT);
+	}
+}
+
 int mtk_clk_simple_probe(struct platform_device *pdev)
 {
 	const struct mtk_clk_desc *mcd;

drivers/clk/mediatek/clk-mtk.h

@@ -176,9 +176,11 @@ struct mtk_clk_divider {
 		.div_width = _width,				\
 }
 
-void mtk_clk_register_dividers(const struct mtk_clk_divider *mcds,
-			int num, void __iomem *base, spinlock_t *lock,
-				struct clk_onecell_data *clk_data);
+void mtk_clk_register_dividers(const struct mtk_clk_divider *mcds, int num,
+			       void __iomem *base, spinlock_t *lock,
+			       struct clk_onecell_data *clk_data);
+void mtk_clk_unregister_dividers(const struct mtk_clk_divider *mcds, int num,
+				 struct clk_onecell_data *clk_data);
 
 struct clk_onecell_data *mtk_alloc_clk_data(unsigned int clk_num);
 void mtk_free_clk_data(struct clk_onecell_data *clk_data);