clk: apn806: Turn the eMMC clock as optional for dts backwards compatible

First version of the binding didn't have the eMMC clock. This patch
allows to not registering the eMMC clock if it is not present in the
device tree. Then the device tree can be backwards compatible.

Suggested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/clk/mvebu/ap806-system-controller.c b/drivers/clk/mvebu/ap806-system-controller.c
index 901d89c4ab4ae4a46611c50ea3a071b34fc0dca5..103fe18a3c29fe1bcfbd4665bc958381b060ae5b 100644 (file)
--- a/drivers/clk/mvebu/ap806-system-controller.c
+++ b/drivers/clk/mvebu/ap806-system-controller.c
@@ -136,13 +136,19 @@ static int ap806_syscon_clk_probe(struct platform_device *pdev)
        }
 
        /* eMMC Clock is fixed clock divided by 3 */
-       of_property_read_string_index(np, "clock-output-names",
-                                     4, &name);
-       ap806_clks[4] = clk_register_fixed_factor(NULL, name, fixedclk_name,
-                                                 0, 1, 3);
-       if (IS_ERR(ap806_clks[4])) {
-               ret = PTR_ERR(ap806_clks[4]);
-               goto fail4;
+       if (of_property_read_string_index(np, "clock-output-names",
+                                         4, &name)) {
+               ap806_clk_data.clk_num--;
+               dev_warn(&pdev->dev,
+                        "eMMC clock mising: update the device tree!\n");
+       } else {
+               ap806_clks[4] = clk_register_fixed_factor(NULL, name,
+                                                         fixedclk_name,
+                                                         0, 1, 3);
+               if (IS_ERR(ap806_clks[4])) {
+                       ret = PTR_ERR(ap806_clks[4]);
+                       goto fail4;
+               }
        }
 
        of_clk_add_provider(np, of_clk_src_onecell_get, &ap806_clk_data);