Several clock API functions handle NULL clocks when the Common Clock
Framework is used, while their legacy SH counterparts don't, and would
just crash when a NULL clock is passed.

Add NULL checks to clk_get_rate(), clk_set_rate(), clk_get_parent(), and
clk_round_rate(), to avoid different behavior in drivers shared between
legacy and CCF-based platforms.

Signed-off-by: Geert Uytterhoeven <[email protected]>
---
Note that there are still differences in return values (e.g. zero vs. an
error code). These are not changed, as callers in legacy code may depend
on specific values.
---
 drivers/sh/clk/core.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/sh/clk/core.c b/drivers/sh/clk/core.c
index be56b22ca941..c9afc5681474 100644
--- a/drivers/sh/clk/core.c
+++ b/drivers/sh/clk/core.c
@@ -469,6 +469,9 @@ void clk_enable_init_clocks(void)
 
 unsigned long clk_get_rate(struct clk *clk)
 {
+       if (!clk)
+               return 0;
+
        return clk->rate;
 }
 EXPORT_SYMBOL_GPL(clk_get_rate);
@@ -478,6 +481,9 @@ int clk_set_rate(struct clk *clk, unsigned long rate)
        int ret = -EOPNOTSUPP;
        unsigned long flags;
 
+       if (!clk)
+               return 0;
+
        spin_lock_irqsave(&clock_lock, flags);
 
        if (likely(clk->ops && clk->ops->set_rate)) {
@@ -535,12 +541,18 @@ EXPORT_SYMBOL_GPL(clk_set_parent);
 
 struct clk *clk_get_parent(struct clk *clk)
 {
+       if (!clk)
+               return NULL;
+
        return clk->parent;
 }
 EXPORT_SYMBOL_GPL(clk_get_parent);
 
 long clk_round_rate(struct clk *clk, unsigned long rate)
 {
+       if (!clk)
+               return 0;
+
        if (likely(clk->ops && clk->ops->round_rate)) {
                unsigned long flags, rounded;
 
-- 
1.9.1

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