clk: mediatek: cpumux: Implement error handling in register API

The cpumux clk type registration function does not stop or return errors
if any clk failed to be registered, nor does it implement an error
handling path. This may result in a partially working device if any
step failed.

Make the register function return proper error codes, and bail out if
errors occur. Proper cleanup, i.e. unregister any clks that were
successfully registered, is done in the new error path.

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/20220208124034.414635-22-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-cpumux.c

@@ -123,13 +123,26 @@ int mtk_clk_register_cpumuxes(struct device_node *node,
 		clk = mtk_clk_register_cpumux(mux, regmap);
 		if (IS_ERR(clk)) {
 			pr_err("Failed to register clk %s: %pe\n", mux->name, clk);
-			continue;
+			goto err;
 		}
 
 		clk_data->clks[mux->id] = clk;
 	}
 
 	return 0;
+
+err:
+	while (--i >= 0) {
+		const struct mtk_composite *mux = &clks[i];
+
+		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);
+	}
+
+	return PTR_ERR(clk);
 }
 
 void mtk_clk_unregister_cpumuxes(const struct mtk_composite *clks, int num,