linux-stable/drivers/gpio/gpio-altera-a10sr.c
Gustavo A. R. Silva 1a20c3f8e8 gpio: altera-a10sr: 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
   1954     600       0    2554     9fa drivers/gpio/gpio-altera-a10sr.o

after:
   text    data     bss     dec     hex filename
   1655     512       0    2167     877 drivers/gpio/gpio-altera-a10sr.o

Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Reviewed-by: Thor Thayer <thor.thayer@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-08-14 15:01:12 +02:00

130 lines
3.5 KiB
C

/*
* Copyright Intel Corporation (C) 2014-2016. All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*
* GPIO driver for Altera Arria10 MAX5 System Resource Chip
*
* Adapted from gpio-tps65910.c
*/
#include <linux/gpio/driver.h>
#include <linux/mfd/altera-a10sr.h>
#include <linux/module.h>
/**
* struct altr_a10sr_gpio - Altera Max5 GPIO device private data structure
* @gp: : instance of the gpio_chip
* @regmap: the regmap from the parent device.
*/
struct altr_a10sr_gpio {
struct gpio_chip gp;
struct regmap *regmap;
};
static int altr_a10sr_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
struct altr_a10sr_gpio *gpio = gpiochip_get_data(chip);
int ret, val;
ret = regmap_read(gpio->regmap, ALTR_A10SR_PBDSW_REG, &val);
if (ret < 0)
return ret;
return !!(val & BIT(offset - ALTR_A10SR_LED_VALID_SHIFT));
}
static void altr_a10sr_gpio_set(struct gpio_chip *chip, unsigned int offset,
int value)
{
struct altr_a10sr_gpio *gpio = gpiochip_get_data(chip);
regmap_update_bits(gpio->regmap, ALTR_A10SR_LED_REG,
BIT(ALTR_A10SR_LED_VALID_SHIFT + offset),
value ? BIT(ALTR_A10SR_LED_VALID_SHIFT + offset)
: 0);
}
static int altr_a10sr_gpio_direction_input(struct gpio_chip *gc,
unsigned int nr)
{
if (nr >= (ALTR_A10SR_IN_VALID_RANGE_LO - ALTR_A10SR_LED_VALID_SHIFT))
return 0;
return -EINVAL;
}
static int altr_a10sr_gpio_direction_output(struct gpio_chip *gc,
unsigned int nr, int value)
{
if (nr <= (ALTR_A10SR_OUT_VALID_RANGE_HI - ALTR_A10SR_LED_VALID_SHIFT))
return 0;
return -EINVAL;
}
static const struct gpio_chip altr_a10sr_gc = {
.label = "altr_a10sr_gpio",
.owner = THIS_MODULE,
.get = altr_a10sr_gpio_get,
.set = altr_a10sr_gpio_set,
.direction_input = altr_a10sr_gpio_direction_input,
.direction_output = altr_a10sr_gpio_direction_output,
.can_sleep = true,
.ngpio = 12,
.base = -1,
};
static int altr_a10sr_gpio_probe(struct platform_device *pdev)
{
struct altr_a10sr_gpio *gpio;
int ret;
struct altr_a10sr *a10sr = dev_get_drvdata(pdev->dev.parent);
gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
if (!gpio)
return -ENOMEM;
gpio->regmap = a10sr->regmap;
gpio->gp = altr_a10sr_gc;
gpio->gp.parent = pdev->dev.parent;
gpio->gp.of_node = pdev->dev.of_node;
ret = devm_gpiochip_add_data(&pdev->dev, &gpio->gp, gpio);
if (ret < 0) {
dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
return ret;
}
platform_set_drvdata(pdev, gpio);
return 0;
}
static const struct of_device_id altr_a10sr_gpio_of_match[] = {
{ .compatible = "altr,a10sr-gpio" },
{ },
};
MODULE_DEVICE_TABLE(of, altr_a10sr_gpio_of_match);
static struct platform_driver altr_a10sr_gpio_driver = {
.probe = altr_a10sr_gpio_probe,
.driver = {
.name = "altr_a10sr_gpio",
.of_match_table = of_match_ptr(altr_a10sr_gpio_of_match),
},
};
module_platform_driver(altr_a10sr_gpio_driver);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Thor Thayer <tthayer@opensource.altera.com>");
MODULE_DESCRIPTION("Altera Arria10 System Resource Chip GPIO");