pinctrl: nomadik: abx500: constify gpio_chip structure

This structure is only used to copy into another structure, so declare
it as const.

This issue was detected using Coccinelle and the following semantic patch:

@r disable optional_qualifier@
identifier i;
position p;
@@
static struct gpio_chip i@p = { ... };

@ok@
identifier r.i;
expression e;
position p;
@@
e = i@p;

@bad@
position p != {r.p,ok.p};
identifier r.i;
struct gpio_chip e;
@@
e@i@p

@depends on !bad disable optional_qualifier@
identifier r.i;
@@
static
+const
 struct gpio_chip i = { ... };

In the following log you can see a significant difference in the code size
and data segment, hence in the dec segment. This log is the output
of the size command, before and after the code change:

before:
   text    data     bss     dec     hex filename
  17545    5376       0   22921    5989 drivers/pinctrl/nomadik/pinctrl-abx500.o

after:
            bss     dec     hex filename
  17273    5320       0   22593    5841 drivers/pinctrl/nomadik/pinctrl-abx500.o

Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/pinctrl/nomadik/pinctrl-abx500.c b/drivers/pinctrl/nomadik/pinctrl-abx500.c
index f95001bc1d5804a8dfe07fbb41800c8b394cb0c2..b32c0d6020247e0d7d5e0c2cdb5d516643942a0b 100644 (file)
--- a/drivers/pinctrl/nomadik/pinctrl-abx500.c
+++ b/drivers/pinctrl/nomadik/pinctrl-abx500.c
@@ -647,7 +647,7 @@ static inline void abx500_gpio_dbg_show_one(struct seq_file *s,
 #define abx500_gpio_dbg_show   NULL
 #endif
 
-static struct gpio_chip abx500gpio_chip = {
+static const struct gpio_chip abx500gpio_chip = {
        .label                  = "abx500-gpio",
        .owner                  = THIS_MODULE,
        .request                = gpiochip_generic_request,