From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <jic23@cam.ac.uk>
Message-ID: <4DAB4835.4020606@cam.ac.uk>
Date: Sun, 17 Apr 2011 21:06:13 +0100
From: Jonathan Cameron <jic23@cam.ac.uk>
MIME-Version: 1.0
To: Jonathan Cameron <jic23@cam.ac.uk>
CC: linux-iio@vger.kernel.org
Subject: Re: [PATCH 53/70] staging:iio: Add core attribute handling for name
 of device.
References: <1303067203-4894-1-git-send-email-jic23@cam.ac.uk> <1303067203-4894-54-git-send-email-jic23@cam.ac.uk>
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On 04/17/11 20:06, Jonathan Cameron wrote:
> Saves on a fair bit of code replication.
I clearly didn't think this through properly.  It can be done much
more neatly with a single static iio_dev_attr and just explicitly
adding and removing it.  See the trigger equivalent in the
iio-onwards tree that I have just pushed.

Jonathan
> 
> Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
> ---
>  drivers/staging/iio/iio.h               |    2 +-
>  drivers/staging/iio/industrialio-core.c |   36 ++++++++++++++++++++++++++++++-
>  2 files changed, 36 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/iio/iio.h b/drivers/staging/iio/iio.h
> index b818f5f..febf20e 100644
> --- a/drivers/staging/iio/iio.h
> +++ b/drivers/staging/iio/iio.h
> @@ -231,7 +231,7 @@ struct iio_dev {
>  	int num_channels;
>  	struct list_head channel_attr_list;
>  
> -	char *name; /*device name - IMPLEMENT */
> +	const char *name;
>  	int (*read_raw)(struct iio_dev *indio_dev,
>  			struct iio_chan_spec const *chan,
>  			int *val,
> diff --git a/drivers/staging/iio/industrialio-core.c b/drivers/staging/iio/industrialio-core.c
> index 2e2e51d..67e7ade 100644
> --- a/drivers/staging/iio/industrialio-core.c
> +++ b/drivers/staging/iio/industrialio-core.c
> @@ -610,6 +610,13 @@ static void iio_device_remove_and_free_read_attr(struct iio_dev *dev_info,
>  	kfree(p->dev_attr.attr.name);
>  	kfree(p);
>  }
> +static ssize_t iio_show_dev_name(struct device *dev,
> +				 struct device_attribute *attr,
> +				 char *buf)
> +{
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +	return sprintf(buf, "%s\n", indio_dev->name);
> +}
>  
>  static int iio_device_register_sysfs(struct iio_dev *dev_info)
>  {
> @@ -638,8 +645,35 @@ static int iio_device_register_sysfs(struct iio_dev *dev_info)
>  			if (ret < 0)
>  				goto error_clear_attrs;
>  		}
> -
> +	if (dev_info->name) {
> +		p = kzalloc(sizeof *p, GFP_KERNEL);
> +		if (p == NULL) {
> +			ret = -ENOMEM;
> +			goto error_clear_attrs;
> +		}
> +		sysfs_attr_init(&p->dev_attr.attr);
> +	
> +		p->dev_attr.attr.name = kstrdup("name", GFP_KERNEL);
> +		if (p->dev_attr.attr.name == NULL) {
> +			ret = -ENOMEM;
> +			kfree(p);
> +			goto error_free_attr;
> +		}
> +		p->dev_attr.attr.mode = S_IRUGO;
> +		p->dev_attr.show = &iio_show_dev_name;
> +		ret = sysfs_add_file_to_group(&dev_info->dev.kobj,
> +					      &p->dev_attr.attr, NULL);
> +		if (ret < 0)
> +			goto error_free_name_name;	
> +		
> +		list_add(&p->l, &dev_info->channel_attr_list);
> +	}
>  	return 0;
> +
> +error_free_name_name:
> +	kfree(p->dev_attr.attr.name);
> +error_free_attr:
> +	kfree(p);
>  error_clear_attrs:
>  	list_for_each_entry_safe(p, n,
>  				 &dev_info->channel_attr_list, l) {