Re: [PATCHv3] support for AD5820 camera auto-focus coil

From: Pavel Machek
Date: Tue May 24 2016 - 16:21:11 EST


Hi!

> >>devm_regulator_get()?
> >
> >I'd rather avoid devm_ here. Driver is simple enough to allow it.
> >
>
> Now thinking about it, what would happen here if regulator_get() returns
> -EPROBE_DEFER? Wouldn't it be better to move regulator_get to the probe()
> function, something like:

Ok, I can do it.

Oh, and don't try to complain about newlines before returns. It looks
better this way.

> static int ad5820_probe(struct i2c_client *client,
> const struct i2c_device_id *devid)
> {
> struct ad5820_device *coil;
> int ret = 0;
>
> coil = devm_kzalloc(sizeof(*coil), GFP_KERNEL);
> if (coil == NULL)
> return -ENOMEM;
>
> coil->vana = devm_regulator_get(&client->dev, NULL);
> if (IS_ERR(coil->vana)) {
> ret = PTR_ERR(coil->vana);
> if (ret != -EPROBE_DEFER)
> dev_err(&client->dev, "could not get regulator for vana\n");
> return ret;
> }
>
> mutex_init(&coil->power_lock);
> ...
>
> with the appropriate changes to remove() because of the devm API
> usage.

Something like this?

diff --git a/drivers/media/i2c/ad5820.c b/drivers/media/i2c/ad5820.c
index f956bd3..f871366 100644
--- a/drivers/media/i2c/ad5820.c
+++ b/drivers/media/i2c/ad5820.c
@@ -8,7 +8,7 @@
* Copyright (C) 2016 Pavel Machek <pavel@xxxxxx>
*
* Contact: Tuukka Toivonen
- * Sakari Ailus
+ * Sakari Ailus
*
* Based on af_d88.c by Texas Instruments.
*
@@ -263,13 +263,6 @@ static int ad5820_init_controls(struct ad5820_device *coil)
static int ad5820_registered(struct v4l2_subdev *subdev)
{
struct ad5820_device *coil = to_ad5820_device(subdev);
- struct i2c_client *client = v4l2_get_subdevdata(subdev);
-
- coil->vana = regulator_get(&client->dev, "VANA");
- if (IS_ERR(coil->vana)) {
- dev_err(&client->dev, "could not get regulator for vana\n");
- return -ENODEV;
- }

return ad5820_init_controls(coil);
}
@@ -367,10 +360,18 @@ static int ad5820_probe(struct i2c_client *client,
struct ad5820_device *coil;
int ret = 0;

- coil = kzalloc(sizeof(*coil), GFP_KERNEL);
+ coil = devm_kzalloc(sizeof(*coil), GFP_KERNEL);
if (!coil)
return -ENOMEM;

+ coil->vana = devm_regulator_get(&client->dev, NULL);
+ if (IS_ERR(coil->vana)) {
+ ret = PTR_ERR(coil->vana);
+ if (ret != -EPROBE_DEFER)
+ dev_err(&client->dev, "could not get regulator for vana\n");
+ return ret;
+ }
+
mutex_init(&coil->power_lock);

v4l2_i2c_subdev_init(&coil->subdev, client, &ad5820_ops);
@@ -390,10 +391,6 @@ static int ad5820_probe(struct i2c_client *client,

cleanup:
media_entity_cleanup(&coil->subdev.entity);
-
-free:
- kfree(coil);
-
return ret;
}

@@ -405,11 +402,6 @@ static int __exit ad5820_remove(struct i2c_client *client)
v4l2_device_unregister_subdev(&coil->subdev);
v4l2_ctrl_handler_free(&coil->ctrls);
media_entity_cleanup(&coil->subdev.entity);
- if (coil->vana)
- regulator_put(coil->vana);
-
- kfree(coil);
-
return 0;
}



--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html