pinctrl: bcm2835: constify gpio_chip structure
This structure is only used to copy into other 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
18958 9000 128 28086 6db6 drivers/pinctrl/bcm/pinctrl-bcm2835.o
after:
text data bss dec hex filename
18764 8912 128 27804 6c9c drivers/pinctrl/bcm/pinctrl-bcm2835.o
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Acked-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/pinctrl/bcm/pinctrl-bcm2835.c b/drivers/pinctrl/bcm/pinctrl-bcm2835.c
index 2308831..7203f35 100644
--- a/drivers/pinctrl/bcm/pinctrl-bcm2835.c
+++ b/drivers/pinctrl/bcm/pinctrl-bcm2835.c
@@ -353,7 +353,7 @@ static int bcm2835_gpio_direction_output(struct gpio_chip *chip,
return pinctrl_gpio_direction_output(chip->base + offset);
}
-static struct gpio_chip bcm2835_gpio_chip = {
+static const struct gpio_chip bcm2835_gpio_chip = {
.label = MODULE_NAME,
.owner = THIS_MODULE,
.request = gpiochip_generic_request,