[PATCH] i2c: dev: make i2c_dev_class a static const structure

From: Ivan Orlov
Date: Thu Aug 10 2023 - 13:46:43 EST


Now that the driver core allows for struct class to be in read-only
memory, move the i2c_dev_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at boot time.

Suggested-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ivan Orlov <ivan.orlov0322@xxxxxxxxx>
---
drivers/i2c/i2c-dev.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
index a01b59e3599b..a91201509bc1 100644
--- a/drivers/i2c/i2c-dev.c
+++ b/drivers/i2c/i2c-dev.c
@@ -636,7 +636,10 @@ static const struct file_operations i2cdev_fops = {

/* ------------------------------------------------------------------------- */

-static struct class *i2c_dev_class;
+static const struct class i2c_dev_class = {
+ .name = "i2c-dev",
+ .dev_groups = i2c_groups,
+};

static void i2cdev_dev_release(struct device *dev)
{
@@ -665,7 +668,7 @@ static int i2cdev_attach_adapter(struct device *dev)

device_initialize(&i2c_dev->dev);
i2c_dev->dev.devt = MKDEV(I2C_MAJOR, adap->nr);
- i2c_dev->dev.class = i2c_dev_class;
+ i2c_dev->dev.class = &i2c_dev_class;
i2c_dev->dev.parent = &adap->dev;
i2c_dev->dev.release = i2cdev_dev_release;

@@ -751,12 +754,9 @@ static int __init i2c_dev_init(void)
if (res)
goto out;

- i2c_dev_class = class_create("i2c-dev");
- if (IS_ERR(i2c_dev_class)) {
- res = PTR_ERR(i2c_dev_class);
+ res = class_register(&i2c_dev_class);
+ if (res)
goto out_unreg_chrdev;
- }
- i2c_dev_class->dev_groups = i2c_groups;

/* Keep track of adapters which will be added or removed later */
res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier);
@@ -769,7 +769,7 @@ static int __init i2c_dev_init(void)
return 0;

out_unreg_class:
- class_destroy(i2c_dev_class);
+ class_unregister(&i2c_dev_class);
out_unreg_chrdev:
unregister_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS);
out:
@@ -781,7 +781,7 @@ static void __exit i2c_dev_exit(void)
{
bus_unregister_notifier(&i2c_bus_type, &i2cdev_notifier);
i2c_for_each_dev(NULL, i2c_dev_detach_adapter);
- class_destroy(i2c_dev_class);
+ class_unregister(&i2c_dev_class);
unregister_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS);
}

--
2.34.1