clk: mediatek: mtk: Implement error handling in register APIs

The remaining clk registration functions do not stop or return errors
if any clk failed to be registered, nor do they implement error
handling paths. This may result in a partially working device if any
step fails.

Make the register functions 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.

This also makes the |struct clk_data *| argument mandatory, as it is
used to track the list of clks registered.

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/20220208124034.414635-27-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

@@ -53,29 +53,46 @@ void mtk_free_clk_data(struct clk_onecell_data *clk_data)
 	kfree(clk_data);
 }
 
-void mtk_clk_register_fixed_clks(const struct mtk_fixed_clk *clks,
-		int num, struct clk_onecell_data *clk_data)
+int mtk_clk_register_fixed_clks(const struct mtk_fixed_clk *clks, int num,
+				struct clk_onecell_data *clk_data)
 {
 	int i;
 	struct clk *clk;
 
+	if (!clk_data)
+		return -ENOMEM;
+
 	for (i = 0; i < num; i++) {
 		const struct mtk_fixed_clk *rc = &clks[i];
 
-		if (clk_data && !IS_ERR_OR_NULL(clk_data->clks[rc->id]))
+		if (!IS_ERR_OR_NULL(clk_data->clks[rc->id]))
 			continue;
 
 		clk = clk_register_fixed_rate(NULL, rc->name, rc->parent, 0,
 					      rc->rate);
 
 		if (IS_ERR(clk)) {
 			pr_err("Failed to register clk %s: %pe\n", rc->name, clk);
-			continue;
+			goto err;
 		}
 
-		if (clk_data)
-			clk_data->clks[rc->id] = clk;
+		clk_data->clks[rc->id] = clk;
 	}
+
+	return 0;
+
+err:
+	while (--i >= 0) {
+		const struct mtk_fixed_clk *rc = &clks[i];
+
+		if (IS_ERR_OR_NULL(clk_data->clks[rc->id]))
+			continue;
+
+		clk_unregister_fixed_rate(clk_data->clks[rc->id]);
+		clk_data->clks[rc->id] = ERR_PTR(-ENOENT);
+	}
+
+	return PTR_ERR(clk);
 }
 EXPORT_SYMBOL_GPL(mtk_clk_register_fixed_clks);
 
@@ -99,29 +116,46 @@ void mtk_clk_unregister_fixed_clks(const struct mtk_fixed_clk *clks, int num,
 }
 EXPORT_SYMBOL_GPL(mtk_clk_unregister_fixed_clks);
 
-void mtk_clk_register_factors(const struct mtk_fixed_factor *clks,
-		int num, struct clk_onecell_data *clk_data)
+int mtk_clk_register_factors(const struct mtk_fixed_factor *clks, int num,
+			     struct clk_onecell_data *clk_data)
 {
 	int i;
 	struct clk *clk;
 
+	if (!clk_data)
+		return -ENOMEM;
+
 	for (i = 0; i < num; i++) {
 		const struct mtk_fixed_factor *ff = &clks[i];
 
-		if (clk_data && !IS_ERR_OR_NULL(clk_data->clks[ff->id]))
+		if (!IS_ERR_OR_NULL(clk_data->clks[ff->id]))
 			continue;
 
 		clk = clk_register_fixed_factor(NULL, ff->name, ff->parent_name,
 				CLK_SET_RATE_PARENT, ff->mult, ff->div);
 
 		if (IS_ERR(clk)) {
 			pr_err("Failed to register clk %s: %pe\n", ff->name, clk);
-			continue;
+			goto err;
 		}
 
-		if (clk_data)
-			clk_data->clks[ff->id] = clk;
+		clk_data->clks[ff->id] = clk;
+	}
+
+	return 0;
+
+err:
+	while (--i >= 0) {
+		const struct mtk_fixed_factor *ff = &clks[i];
+
+		if (IS_ERR_OR_NULL(clk_data->clks[ff->id]))
+			continue;
+
+		clk_unregister_fixed_factor(clk_data->clks[ff->id]);
+		clk_data->clks[ff->id] = ERR_PTR(-ENOENT);
 	}
+
+	return PTR_ERR(clk);
 }
 EXPORT_SYMBOL_GPL(mtk_clk_register_factors);
 
@@ -258,13 +292,16 @@ static void mtk_clk_unregister_composite(struct clk *clk)
 	kfree(mux);
 }
 
-void mtk_clk_register_composites(const struct mtk_composite *mcs,
-		int num, void __iomem *base, spinlock_t *lock,
-		struct clk_onecell_data *clk_data)
+int mtk_clk_register_composites(const struct mtk_composite *mcs, int num,
+				void __iomem *base, spinlock_t *lock,
+				struct clk_onecell_data *clk_data)
 {
 	struct clk *clk;
 	int i;
 
+	if (!clk_data)
+		return -ENOMEM;
+
 	for (i = 0; i < num; i++) {
 		const struct mtk_composite *mc = &mcs[i];
 
@@ -275,12 +312,26 @@ void mtk_clk_register_composites(const struct mtk_composite *mcs,
 
 		if (IS_ERR(clk)) {
 			pr_err("Failed to register clk %s: %pe\n", mc->name, clk);
-			continue;
+			goto err;
 		}
 
-		if (clk_data)
-			clk_data->clks[mc->id] = clk;
+		clk_data->clks[mc->id] = clk;
+	}
+
+	return 0;
+
+err:
+	while (--i >= 0) {
+		const struct mtk_composite *mc = &mcs[i];
+
+		if (IS_ERR_OR_NULL(clk_data->clks[mcs->id]))
+			continue;
+
+		mtk_clk_unregister_composite(clk_data->clks[mc->id]);
+		clk_data->clks[mc->id] = ERR_PTR(-ENOENT);
 	}
+
+	return PTR_ERR(clk);
 }
 EXPORT_SYMBOL_GPL(mtk_clk_register_composites);
 
@@ -304,17 +355,20 @@ void mtk_clk_unregister_composites(const struct mtk_composite *mcs, int num,
 }
 EXPORT_SYMBOL_GPL(mtk_clk_unregister_composites);
 
-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)
+int mtk_clk_register_dividers(const struct mtk_clk_divider *mcds, int num,
+			      void __iomem *base, spinlock_t *lock,
+			      struct clk_onecell_data *clk_data)
 {
 	struct clk *clk;
 	int i;
 
+	if (!clk_data)
+		return -ENOMEM;
+
 	for (i = 0; i <  num; i++) {
 		const struct mtk_clk_divider *mcd = &mcds[i];
 
-		if (clk_data && !IS_ERR_OR_NULL(clk_data->clks[mcd->id]))
+		if (!IS_ERR_OR_NULL(clk_data->clks[mcd->id]))
 			continue;
 
 		clk = clk_register_divider(NULL, mcd->name, mcd->parent_name,
@@ -323,12 +377,26 @@ void mtk_clk_register_dividers(const struct mtk_clk_divider *mcds,
 
 		if (IS_ERR(clk)) {
 			pr_err("Failed to register clk %s: %pe\n", mcd->name, clk);
-			continue;
+			goto err;
 		}
 
-		if (clk_data)
-			clk_data->clks[mcd->id] = clk;
+		clk_data->clks[mcd->id] = clk;
+	}
+
+	return 0;
+
+err:
+	while (--i >= 0) {
+		const struct mtk_clk_divider *mcd = &mcds[i];
+
+		if (IS_ERR_OR_NULL(clk_data->clks[mcd->id]))
+			continue;
+
+		mtk_clk_unregister_composite(clk_data->clks[mcd->id]);
+		clk_data->clks[mcd->id] = ERR_PTR(-ENOENT);
 	}
+
+	return PTR_ERR(clk);
 }
 
 void mtk_clk_unregister_dividers(const struct mtk_clk_divider *mcds, int num,

drivers/clk/mediatek/clk-mtk.h

@@ -34,8 +34,8 @@ struct mtk_fixed_clk {
 		.rate = _rate,				\
 	}
 
-void mtk_clk_register_fixed_clks(const struct mtk_fixed_clk *clks, int num,
-				 struct clk_onecell_data *clk_data);
+int mtk_clk_register_fixed_clks(const struct mtk_fixed_clk *clks, int num,
+				struct clk_onecell_data *clk_data);
 void mtk_clk_unregister_fixed_clks(const struct mtk_fixed_clk *clks, int num,
 				   struct clk_onecell_data *clk_data);
 
@@ -55,8 +55,8 @@ struct mtk_fixed_factor {
 		.div = _div,				\
 	}
 
-void mtk_clk_register_factors(const struct mtk_fixed_factor *clks, int num,
-			      struct clk_onecell_data *clk_data);
+int mtk_clk_register_factors(const struct mtk_fixed_factor *clks, int num,
+			     struct clk_onecell_data *clk_data);
 void mtk_clk_unregister_factors(const struct mtk_fixed_factor *clks, int num,
 				struct clk_onecell_data *clk_data);
 
@@ -150,9 +150,9 @@ struct mtk_composite {
 struct clk *mtk_clk_register_composite(const struct mtk_composite *mc,
 		void __iomem *base, spinlock_t *lock);
 
-void mtk_clk_register_composites(const struct mtk_composite *mcs,
-		int num, void __iomem *base, spinlock_t *lock,
-		struct clk_onecell_data *clk_data);
+int mtk_clk_register_composites(const struct mtk_composite *mcs, int num,
+				void __iomem *base, spinlock_t *lock,
+				struct clk_onecell_data *clk_data);
 void mtk_clk_unregister_composites(const struct mtk_composite *mcs, int num,
 				   struct clk_onecell_data *clk_data);
 
@@ -178,9 +178,9 @@ 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);
+int 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);