counter: Use container_of instead of drvdata to track counter_device

The counter core uses drvdata to find a struct counter_device from a
struct device. However as the device is a member of struct counter_device,
the lookup can be done faster (and a bit type safe) using container_of.

There are no other users of drvdata, so the call to dev_set_drvdata can
go away, too.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211230150300.72196-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/counter/counter-core.c b/drivers/counter/counter-core.c
index 5acc545..f053a43 100644 (file)
--- a/drivers/counter/counter-core.c
+++ b/drivers/counter/counter-core.c
@@ -26,7 +26,8 @@ static DEFINE_IDA(counter_ida);
 
 static void counter_device_release(struct device *dev)
 {
-       struct counter_device *const counter = dev_get_drvdata(dev);
+       struct counter_device *const counter =
+               container_of(dev, struct counter_device, dev);
 
        counter_chrdev_remove(counter);
        ida_free(&counter_ida, dev->id);
@@ -78,7 +79,6 @@ int counter_register(struct counter_device *const counter)
                dev->of_node = counter->parent->of_node;
        }
        device_initialize(dev);
-       dev_set_drvdata(dev, counter);
 
        err = counter_sysfs_add(counter);
        if (err < 0)