clk: sunxi: improve divider_clk error handling and reporting

We now report a failing ioremap, failing output names parsing,
failures in table registration and in the final step.
Also there was a bug where clk_register_divider_table() would return
an ERR_PTR value instead of NULL, which we were checking for.
We now implement proper rollback in case of an error.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

1 files changed, 33 insertions, 3 deletions

diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
index 775e13776f84..4bd09179a401 100644
--- a/drivers/clk/sunxi/clk-sunxi.c
+++ b/drivers/clk/sunxi/clk-sunxi.c
@@ -805,17 +805,47 @@ static void __init sunxi_divider_clk_setup(struct device_node *node,
         void __iomem *reg;
 
         reg = of_iomap(node, 0);
+        if (!reg) {
+                pr_err("Could not map registers for mux-clk: %s\n",
+                       of_node_full_name(node));
+                return;
+        }
 
         clk_parent = of_clk_get_parent_name(node, 0);
 
-        of_property_read_string(node, "clock-output-names", &clk_name);
+        if (of_property_read_string(node, "clock-output-names", &clk_name)) {
+                pr_err("%s: could not read clock-output-names from \"%s\"\n",
+                       __func__, of_node_full_name(node));
+                goto out_unmap;
+        }
 
         clk = clk_register_divider_table(NULL, clk_name, clk_parent, 0,
                                          reg, data->shift, data->width,
                                          data->pow ? CLK_DIVIDER_POWER_OF_TWO : 0,
                                          data->table, &clk_lock);
-        if (clk)
-                of_clk_add_provider(node, of_clk_src_simple_get, clk);
+        if (IS_ERR(clk)) {
+                pr_err("%s: failed to register divider clock %s: %ld\n",
+                       __func__, clk_name, PTR_ERR(clk));
+                goto out_unmap;
+        }
+
+        if (of_clk_add_provider(node, of_clk_src_simple_get, clk)) {
+                pr_err("%s: failed to add clock provider for %s\n",
+                       __func__, clk_name);
+                goto out_unregister;
+        }
+
+        if (clk_register_clkdev(clk, clk_name, NULL)) {
+                of_clk_del_provider(node);
+                goto out_unregister;
+        }
+
+        return;
+out_unregister:
+        clk_unregister_divider(clk);
+
+out_unmap:
+        iounmap(reg);
 }
 
 static void __init sun4i_ahb_clk_setup(struct device_node *node)