clk: return probe defer when DT clock not yet ready

At probe time, a clock device may not be ready when some other device
wants to use it.

This patch lets the functions clk_get/devm_clk_get return a probe defer
when the clock is defined in the DT but not yet available.

Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index f30e6af..cc2ca9a 100644 (file)
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -2466,7 +2466,7 @@ EXPORT_SYMBOL_GPL(of_clk_del_provider);
 struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec)
 {
        struct of_clk_provider *provider;
-       struct clk *clk = ERR_PTR(-ENOENT);
+       struct clk *clk = ERR_PTR(-EPROBE_DEFER);
 
        /* Check if we have such a provider in our array */
        list_for_each_entry(provider, &of_clk_providers, link) {

diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c
index 48f6721..a360b2e 100644 (file)
--- a/drivers/clk/clkdev.c
+++ b/drivers/clk/clkdev.c
@@ -167,6 +167,8 @@ struct clk *clk_get(struct device *dev, const char *con_id)
                clk = of_clk_get_by_name(dev->of_node, con_id);
                if (!IS_ERR(clk))
                        return clk;
+               if (PTR_ERR(clk) == -EPROBE_DEFER)
+                       return clk;
        }
 
        return clk_get_sys(dev_id, con_id);