[PATCH RFC] gpio: sim: access sysfs attributes as const

[Bartosz Golaszewski]

Use the const variant of constainer_of() to access struct
gpio_sim_attribute which wraps the dynamically allocated sysfs
attributes for value and pull of simulated GPIO lines in line with the
currently preferred approach.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxxxxxxxx>
---
Hi Thomas!

Following your talk, I'm sending a patch for the GPIO simulator module
that attempts to constify the sysfs attributes. Please tell me if this
is all I need here as the attributes are part of another struct that's
allocated dynamically. I'm not sure if there's anything more to do here.
---
 drivers/gpio/gpio-sim.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/gpio/gpio-sim.c b/drivers/gpio/gpio-sim.c
index 0c73bec042670fc5706b4a93700e652cbaf3605e..e0ae586cd08d8adbb3c16918607074fce116654e 100644
--- a/drivers/gpio/gpio-sim.c
+++ b/drivers/gpio/gpio-sim.c
@@ -59,10 +59,10 @@ struct gpio_sim_attribute {
 	unsigned int offset;
 };
 
-static struct gpio_sim_attribute *
+static const struct gpio_sim_attribute *
 to_gpio_sim_attr(struct device_attribute *dev_attr)
 {
-	return container_of(dev_attr, struct gpio_sim_attribute, dev_attr);
+	return container_of_const(dev_attr, struct gpio_sim_attribute, dev_attr);
 }
 
 static int gpio_sim_apply_pull(struct gpio_sim_chip *chip,
@@ -272,7 +272,7 @@ static void gpio_sim_dbg_show(struct seq_file *seq, struct gpio_chip *gc)
 static ssize_t gpio_sim_sysfs_val_show(struct device *dev,
 				       struct device_attribute *attr, char *buf)
 {
-	struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
+	const struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
 	struct gpio_sim_chip *chip = dev_get_drvdata(dev);
 	int val;
 
@@ -302,7 +302,7 @@ static ssize_t gpio_sim_sysfs_pull_show(struct device *dev,
 					struct device_attribute *attr,
 					char *buf)
 {
-	struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
+	const struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
 	struct gpio_sim_chip *chip = dev_get_drvdata(dev);
 	int pull;
 
@@ -316,7 +316,7 @@ static ssize_t gpio_sim_sysfs_pull_store(struct device *dev,
 					 struct device_attribute *attr,
 					 const char *buf, size_t len)
 {
-	struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
+	const struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
 	struct gpio_sim_chip *chip = dev_get_drvdata(dev);
 	int ret, pull;
 

---
base-commit: b810335a0699d1810683796b0e3ffe8827ddfe6c
change-id: 20261016-gpio-sim-const-sysfs-attr-350706cc7500

Best regards,
-- 
Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxxxxxxxx>