[PATCH 1/9] of: Add a new macro to declare_of for one parameter function returning a value

From: Daniel Lezcano
Date: Wed Jun 01 2016 - 04:58:44 EST

The macro OF_DECLARE_1 expect a void (*func)(struct device_node *) while the
OF_DECLARE_2 expect a int (*func)(struct device_node *, struct device_node *).

The second one allows to pass an init function returning a value, which make
possible to call the functions in the table and check the return value in order
to catch at a higher level the errors and handle them from there instead of
doing a panic in each driver (well at least this is the case for the clkevt).

Unfortunately the OF_DECLARE_1 does not allow that and that lead to some code
duplication and crappyness in the drivers.

The OF_DECLARE_1 is used by all the clk drivers and the clocksource/clockevent
drivers. It is not possible to do the change in one shot as we have to change
all the init functions.

The OF_DECLARE_2 specifies an init function prototype with two parameters with
the node and its parent. The latter won't be used, ever, in the timer drivers.

Introduce a OF_DECLARE_1_RET macro to be used, and hopefully we can smoothly
and iteratively change the users of OF_DECLARE_1 to use the new macro instead.

Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
include/linux/of.h | 3 +++
1 file changed, 3 insertions(+)

diff --git a/include/linux/of.h b/include/linux/of.h
index 7fcb681..5b396d7 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -944,10 +944,13 @@ static inline int of_get_available_child_count(const struct device_node *np)

typedef int (*of_init_fn_2)(struct device_node *, struct device_node *);
+typedef int (*of_init_fn_1_ret)(struct device_node *);
typedef void (*of_init_fn_1)(struct device_node *);

#define OF_DECLARE_1(table, name, compat, fn) \
_OF_DECLARE(table, name, compat, fn, of_init_fn_1)
+#define OF_DECLARE_1_RET(table, name, compat, fn) \
+ _OF_DECLARE(table, name, compat, fn, of_init_fn_1_ret)
#define OF_DECLARE_2(table, name, compat, fn) \
_OF_DECLARE(table, name, compat, fn, of_init_fn_2)