From: Alexandre Courbot <gnurou@gmail.com>
To: Grant Likely <grant.likely@secretlab.ca>,
Linus Walleij <linus.walleij@linaro.org>
Cc: linux-kernel@vger.kernel.org, gnurou@gmail.com,
Alexandre Courbot <acourbot@nvidia.com>
Subject: [PATCH 2/4] gpiolib: use const parameters when possible
Date: Wed, 13 Feb 2013 16:03:00 +0900 [thread overview]
Message-ID: <1360738983-22436-3-git-send-email-gnurou@gmail.com> (raw)
In-Reply-To: <1360738983-22436-1-git-send-email-gnurou@gmail.com>
From: Alexandre Courbot <acourbot@nvidia.com>
Constify descriptor parameter of gpiod_* functions for those that
should obviously not modify it. This includes value or direction get,
cansleep, and IRQ number query.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
drivers/gpio/gpiolib.c | 29 ++++++++++++++++-------------
1 file changed, 16 insertions(+), 13 deletions(-)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 8a2cf9c..ad6df6b 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -88,13 +88,14 @@ static int gpiod_request(struct gpio_desc *desc, const char *label);
static void gpiod_free(struct gpio_desc *desc);
static int gpiod_direction_input(struct gpio_desc *desc);
static int gpiod_direction_output(struct gpio_desc *desc, int value);
+static int gpiod_get_direction(const struct gpio_desc *desc);
static int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce);
-static int gpiod_get_value_cansleep(struct gpio_desc *desc);
+static int gpiod_get_value_cansleep(const struct gpio_desc *desc);
static void gpiod_set_value_cansleep(struct gpio_desc *desc, int value);
-static int gpiod_get_value(struct gpio_desc *desc);
+static int gpiod_get_value(const struct gpio_desc *desc);
static void gpiod_set_value(struct gpio_desc *desc, int value);
-static int gpiod_cansleep(struct gpio_desc *desc);
-static int gpiod_to_irq(struct gpio_desc *desc);
+static int gpiod_cansleep(const struct gpio_desc *desc);
+static int gpiod_to_irq(const struct gpio_desc *desc);
static int gpiod_export(struct gpio_desc *desc, bool direction_may_change);
static int gpiod_export_link(struct device *dev, const char *name,
struct gpio_desc *desc);
@@ -172,7 +173,7 @@ static int gpio_ensure_requested(struct gpio_desc *desc)
}
/* caller holds gpio_lock *OR* gpio is marked as requested */
-static struct gpio_chip *gpiod_to_chip(struct gpio_desc *desc)
+static struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
{
return desc ? desc->chip : NULL;
}
@@ -207,7 +208,7 @@ static int gpiochip_find_base(int ngpio)
}
/* caller ensures gpio is valid and requested, chip->get_direction may sleep */
-static int gpiod_get_direction(struct gpio_desc *desc)
+static int gpiod_get_direction(const struct gpio_desc *desc)
{
struct gpio_chip *chip;
unsigned offset;
@@ -223,11 +224,13 @@ static int gpiod_get_direction(struct gpio_desc *desc)
if (status > 0) {
/* GPIOF_DIR_IN, or other positive */
status = 1;
- clear_bit(FLAG_IS_OUT, &desc->flags);
+ /* FLAG_IS_OUT is just a cache of the result of get_direction(),
+ * so it does not affect constness per se */
+ clear_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags);
}
if (status == 0) {
/* GPIOF_DIR_OUT */
- set_bit(FLAG_IS_OUT, &desc->flags);
+ set_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags);
}
return status;
}
@@ -263,7 +266,7 @@ static DEFINE_MUTEX(sysfs_lock);
static ssize_t gpio_direction_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
- struct gpio_desc *desc = dev_get_drvdata(dev);
+ const struct gpio_desc *desc = dev_get_drvdata(dev);
ssize_t status;
mutex_lock(&sysfs_lock);
@@ -1818,7 +1821,7 @@ EXPORT_SYMBOL_GPL(gpio_set_debounce);
* It returns the zero or nonzero value provided by the associated
* gpio_chip.get() method; or zero if no such method is provided.
*/
-static int gpiod_get_value(struct gpio_desc *desc)
+static int gpiod_get_value(const struct gpio_desc *desc)
{
struct gpio_chip *chip;
int value;
@@ -1936,7 +1939,7 @@ EXPORT_SYMBOL_GPL(__gpio_set_value);
* This is used directly or indirectly to implement gpio_cansleep(). It
* returns nonzero if access reading or writing the GPIO value can sleep.
*/
-static int gpiod_cansleep(struct gpio_desc *desc)
+static int gpiod_cansleep(const struct gpio_desc *desc)
{
if (!desc)
return 0;
@@ -1959,7 +1962,7 @@ EXPORT_SYMBOL_GPL(__gpio_cansleep);
* It returns the number of the IRQ signaled by this (input) GPIO,
* or a negative errno.
*/
-static int gpiod_to_irq(struct gpio_desc *desc)
+static int gpiod_to_irq(const struct gpio_desc *desc)
{
struct gpio_chip *chip;
int offset;
@@ -1982,7 +1985,7 @@ EXPORT_SYMBOL_GPL(__gpio_to_irq);
* Common examples include ones connected to I2C or SPI chips.
*/
-static int gpiod_get_value_cansleep(struct gpio_desc *desc)
+static int gpiod_get_value_cansleep(const struct gpio_desc *desc)
{
struct gpio_chip *chip;
int value;
--
1.8.1.3
next prev parent reply other threads:[~2013-02-13 7:02 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-13 7:02 [PATCH 0/4] gpiolib: some fixup patches Alexandre Courbot
2013-02-13 7:02 ` [PATCH 1/4] gpiolib: check descriptors validity before use Alexandre Courbot
2013-02-13 22:49 ` Ryan Mallon
2013-02-14 3:00 ` Alexandre Courbot
2013-02-13 7:03 ` Alexandre Courbot [this message]
2014-11-17 9:09 ` [PATCH 2/4] gpiolib: use const parameters when possible Uwe Kleine-König
2014-11-19 8:33 ` Alexandre Courbot
2014-11-19 8:44 ` Uwe Kleine-König
2014-11-19 8:57 ` Alexandre Courbot
2014-11-19 9:02 ` Uwe Kleine-König
2014-11-19 9:07 ` Alexandre Courbot
2014-11-19 10:09 ` Uwe Kleine-König
2014-11-25 7:37 ` Alexandre Courbot
2014-11-25 9:36 ` Janusz Użycki
2013-02-13 7:03 ` [PATCH 3/4] gpiolib: move comment to right function Alexandre Courbot
2013-02-13 7:03 ` [PATCH 4/4] gpiolib: rename local offset variables to "hwgpio" Alexandre Courbot
2013-02-13 22:54 ` Ryan Mallon
2013-02-14 3:11 ` Alexandre Courbot
2013-02-13 7:03 ` Alexandre Courbot
-- strict thread matches above, loose matches on Subject: below --
2013-02-15 5:46 [PATCH v2 0/4] gpiolib: some fixup patches Alexandre Courbot
2013-02-15 5:46 ` [PATCH 2/4] gpiolib: use const parameters when possible Alexandre Courbot
2013-02-26 17:49 ` Grant Likely
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