[i2c] [PATCH 1/2] i2c: Use the driver model reference counting

[David Brownell]

On Wednesday 05 December 2007, Jean Delvare wrote:
> ...
>  int i2c_use_client(struct i2c_client *client)
>  {
> -	int ret;
> -
> -	ret = i2c_inc_use_client(client);
> -	if (ret)
> -		return ret;
> -
> -	client->usage_count++;
> -

if (!client)
	return -EINVAL;

> +	get_device(&client->dev);
>  	return 0;
>  }
>  EXPORT_SYMBOL(i2c_use_client);

... or maybe just change the calling convention to return
null-or-client, matching the more widespread idiom.


>  int i2c_release_client(struct i2c_client *client)
>  {
> -	if (!client->usage_count) {
> -		pr_debug("i2c-core: %s used one too many times\n",
> -			 __FUNCTION__);
> -		return -EPERM;
> -	}
> -
> -	client->usage_count--;
> -	i2c_dec_use_client(client);
> -
> +	put_device(&client->dev);
>  	return 0;
>  }
>  EXPORT_SYMBOL(i2c_release_client);

static inline int i2c_release_client(struct i2c_client *client)
{
	put_device(&client->dev);
	return 0;
}

... though it would be better to change the signature on this one
to void, since it can never fail.