Re: [PATCH 09/11] iio: buffer: Allocate standard attributes in the core

[Hartmut Knaack <knaack.h@gmx.de>]

Lars-Peter Clausen schrieb am 26.11.2014 um 18:55:
> All buffers want at least the length and the enable attribute. Move the
> creation of those attributes to the core instead of having to do this in
> each individual buffer implementation. This allows us to get rid of some
> boiler-plate code.
> 
There are some indentation issues in here, as well. I'll point them out.
> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
> ---
>  drivers/iio/industrialio-buffer.c        | 55 +++++++++++++++++++++-----------
>  drivers/iio/kfifo_buf.c                  | 15 ---------
>  drivers/staging/iio/accel/sca3000_ring.c | 14 ++------
>  include/linux/iio/buffer.h               | 37 ++-------------------
>  4 files changed, 40 insertions(+), 81 deletions(-)
> 
> diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
> index cdc2482..a4d3ff6 100644
> --- a/drivers/iio/industrialio-buffer.c
> +++ b/drivers/iio/industrialio-buffer.c
> @@ -383,10 +383,8 @@ static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
>  	return ret;
>  }
>  
> -
> -ssize_t iio_buffer_read_length(struct device *dev,
> -			       struct device_attribute *attr,
> -			       char *buf)
> +static ssize_t iio_buffer_read_length(struct device *dev,
> +	struct device_attribute *attr, char *buf)
Here.
>  {
>  	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>  	struct iio_buffer *buffer = indio_dev->buffer;
> @@ -397,12 +395,9 @@ ssize_t iio_buffer_read_length(struct device *dev,
>  
>  	return 0;
>  }
> -EXPORT_SYMBOL(iio_buffer_read_length);
>  
> -ssize_t iio_buffer_write_length(struct device *dev,
> -				struct device_attribute *attr,
> -				const char *buf,
> -				size_t len)
> +static ssize_t iio_buffer_write_length(struct device *dev,
> +	struct device_attribute *attr, const char *buf, size_t len)
Here.
>  {
>  	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>  	struct iio_buffer *buffer = indio_dev->buffer;
> @@ -429,16 +424,13 @@ ssize_t iio_buffer_write_length(struct device *dev,
>  
>  	return ret ? ret : len;
>  }
> -EXPORT_SYMBOL(iio_buffer_write_length);
>  
> -ssize_t iio_buffer_show_enable(struct device *dev,
> -			       struct device_attribute *attr,
> -			       char *buf)
> +static ssize_t iio_buffer_show_enable(struct device *dev,
> +	struct device_attribute *attr, char *buf)
Here.
>  {
>  	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>  	return sprintf(buf, "%d\n", iio_buffer_is_active(indio_dev->buffer));
>  }
> -EXPORT_SYMBOL(iio_buffer_show_enable);
>  
>  static int iio_compute_scan_bytes(struct iio_dev *indio_dev,
>  				const unsigned long *mask, bool timestamp)
> @@ -725,10 +717,8 @@ out_unlock:
>  }
>  EXPORT_SYMBOL_GPL(iio_update_buffers);
>  
> -ssize_t iio_buffer_store_enable(struct device *dev,
> -				struct device_attribute *attr,
> -				const char *buf,
> -				size_t len)
> +static ssize_t iio_buffer_store_enable(struct device *dev,
> +	struct device_attribute *attr, const char *buf, size_t len)
Here.
>  {
>  	int ret;
>  	bool requested_state;
> @@ -760,10 +750,14 @@ done:
>  	mutex_unlock(&indio_dev->mlock);
>  	return (ret < 0) ? ret : len;
>  }
> -EXPORT_SYMBOL(iio_buffer_store_enable);
>  
>  static const char * const iio_scan_elements_group_name = "scan_elements";
>  
> +static DEVICE_ATTR(length, S_IRUGO | S_IWUSR, iio_buffer_read_length,
> +	iio_buffer_write_length);
> +static DEVICE_ATTR(enable, S_IRUGO | S_IWUSR,
> +	iio_buffer_show_enable, iio_buffer_store_enable);
> +
And these two here.
>  int iio_buffer_alloc_sysfs(struct iio_dev *indio_dev)
>  {
>  	struct iio_dev_attr *p;
> @@ -775,6 +769,27 @@ int iio_buffer_alloc_sysfs(struct iio_dev *indio_dev)
>  	if (!buffer)
>  		return 0;
>  
> +	attrcount = 0;
> +	if (buffer->attrs) {
> +		while (buffer->attrs[attrcount] != NULL)
> +			attrcount++;
> +	}
> +
> +	buffer->buffer_group.name = "buffer";
> +	buffer->buffer_group.attrs = kcalloc(attrcount + 3,
> +			sizeof(*buffer->buffer_group.attrs), GFP_KERNEL);
> +	if (!buffer->buffer_group.attrs)
> +		return -ENOMEM;
> +
> +	buffer->buffer_group.attrs[0] = &dev_attr_length.attr;
> +	buffer->buffer_group.attrs[1] = &dev_attr_enable.attr;
> +	if (buffer->attrs)
> +		memcpy(&buffer->buffer_group.attrs[2], buffer->attrs,
> +			sizeof(*&buffer->buffer_group.attrs) * (attrcount - 2));
> +	buffer->buffer_group.attrs[attrcount+2] = NULL;
> +
> +	indio_dev->groups[indio_dev->groupcounter++] = &buffer->buffer_group;
> +
>  	if (buffer->scan_el_attrs != NULL) {
>  		attr = buffer->scan_el_attrs->attrs;
>  		while (*attr++ != NULL)
> @@ -839,6 +854,7 @@ error_free_scan_mask:
>  	kfree(buffer->scan_mask);
>  error_cleanup_dynamic:
>  	iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list);
> +	kfree(indio_dev->buffer->buffer_group.attrs);
>  
>  	return ret;
>  }
> @@ -849,6 +865,7 @@ void iio_buffer_free_sysfs(struct iio_dev *indio_dev)
>  		return;
>  
>  	kfree(indio_dev->buffer->scan_mask);
> +	kfree(indio_dev->buffer->buffer_group.attrs);
>  	kfree(indio_dev->buffer->scan_el_group.attrs);
>  	iio_free_chan_devattr_list(&indio_dev->buffer->scan_el_dev_attr_list);
>  }
> diff --git a/drivers/iio/kfifo_buf.c b/drivers/iio/kfifo_buf.c
> index 1258b4e..3b0a3bc 100644
> --- a/drivers/iio/kfifo_buf.c
> +++ b/drivers/iio/kfifo_buf.c
> @@ -52,20 +52,6 @@ static int iio_get_length_kfifo(struct iio_buffer *r)
>  	return r->length;
>  }
>  
> -static IIO_BUFFER_ENABLE_ATTR;
> -static IIO_BUFFER_LENGTH_ATTR;
> -
> -static struct attribute *iio_kfifo_attributes[] = {
> -	&dev_attr_length.attr,
> -	&dev_attr_enable.attr,
> -	NULL,
> -};
> -
> -static struct attribute_group iio_kfifo_attribute_group = {
> -	.attrs = iio_kfifo_attributes,
> -	.name = "buffer",
> -};
> -
>  static int iio_mark_update_needed_kfifo(struct iio_buffer *r)
>  {
>  	struct iio_kfifo *kf = iio_to_kfifo(r);
> @@ -169,7 +155,6 @@ struct iio_buffer *iio_kfifo_allocate(struct iio_dev *indio_dev)
>  		return NULL;
>  	kf->update_needed = true;
>  	iio_buffer_init(&kf->buffer);
> -	kf->buffer.attrs = &iio_kfifo_attribute_group;
>  	kf->buffer.access = &kfifo_access_funcs;
>  	kf->buffer.length = 2;
>  	mutex_init(&kf->user_lock);
> diff --git a/drivers/staging/iio/accel/sca3000_ring.c b/drivers/staging/iio/accel/sca3000_ring.c
> index aa0e5d8..f2f260e 100644
> --- a/drivers/staging/iio/accel/sca3000_ring.c
> +++ b/drivers/staging/iio/accel/sca3000_ring.c
> @@ -140,9 +140,6 @@ static bool sca3000_ring_buf_data_available(struct iio_buffer *r)
>  	return r->stufftoread;
>  }
>  
> -static IIO_BUFFER_ENABLE_ATTR;
> -static IIO_BUFFER_LENGTH_ATTR;
> -
>  /**
>   * sca3000_query_ring_int() is the hardware ring status interrupt enabled
>   **/
> @@ -232,20 +229,13 @@ static IIO_DEVICE_ATTR(in_accel_scale,
>   * only apply to the ring buffer.  At all times full rate and accuracy
>   * is available via direct reading from registers.
>   */
> -static struct attribute *sca3000_ring_attributes[] = {
> -	&dev_attr_length.attr,
> -	&dev_attr_enable.attr,
> +static const struct attribute *sca3000_ring_attributes[] = {
>  	&iio_dev_attr_50_percent.dev_attr.attr,
>  	&iio_dev_attr_75_percent.dev_attr.attr,
>  	&iio_dev_attr_in_accel_scale.dev_attr.attr,
>  	NULL,
>  };
>  
> -static struct attribute_group sca3000_ring_attr = {
> -	.attrs = sca3000_ring_attributes,
> -	.name = "buffer",
> -};
> -
>  static struct iio_buffer *sca3000_rb_allocate(struct iio_dev *indio_dev)
>  {
>  	struct iio_buffer *buf;
> @@ -258,7 +248,7 @@ static struct iio_buffer *sca3000_rb_allocate(struct iio_dev *indio_dev)
>  	ring->private = indio_dev;
>  	buf = &ring->buf;
>  	buf->stufftoread = 0;
> -	buf->attrs = &sca3000_ring_attr;
> +	buf->attrs = sca3000_ring_attributes;
>  	iio_buffer_init(buf);
>  
>  	return buf;
> diff --git a/include/linux/iio/buffer.h b/include/linux/iio/buffer.h
> index 79cdb3d..16b7663 100644
> --- a/include/linux/iio/buffer.h
> +++ b/include/linux/iio/buffer.h
> @@ -83,10 +83,11 @@ struct iio_buffer {
>  	bool					scan_timestamp;
>  	const struct iio_buffer_access_funcs	*access;
>  	struct list_head			scan_el_dev_attr_list;
> +	struct attribute_group			buffer_group;
>  	struct attribute_group			scan_el_group;
>  	wait_queue_head_t			pollq;
>  	bool					stufftoread;
> -	const struct attribute_group *attrs;
> +	const struct attribute			**attrs;
>  	struct list_head			demux_list;
>  	void					*demux_bounce;
>  	struct list_head			buffer_list;
> @@ -148,40 +149,6 @@ static inline int iio_push_to_buffers_with_timestamp(struct iio_dev *indio_dev,
>  
>  int iio_update_demux(struct iio_dev *indio_dev);
>  
> -/**
> - * iio_buffer_read_length() - attr func to get number of datums in the buffer
> - **/
> -ssize_t iio_buffer_read_length(struct device *dev,
> -			       struct device_attribute *attr,
> -			       char *buf);
> -/**
> - * iio_buffer_write_length() - attr func to set number of datums in the buffer
> - **/
> -ssize_t iio_buffer_write_length(struct device *dev,
> -			      struct device_attribute *attr,
> -			      const char *buf,
> -			      size_t len);
> -/**
> - * iio_buffer_store_enable() - attr to turn the buffer on
> - **/
> -ssize_t iio_buffer_store_enable(struct device *dev,
> -				struct device_attribute *attr,
> -				const char *buf,
> -				size_t len);
> -/**
> - * iio_buffer_show_enable() - attr to see if the buffer is on
> - **/
> -ssize_t iio_buffer_show_enable(struct device *dev,
> -			       struct device_attribute *attr,
> -			       char *buf);
> -#define IIO_BUFFER_LENGTH_ATTR DEVICE_ATTR(length, S_IRUGO | S_IWUSR,	\
> -					   iio_buffer_read_length,	\
> -					   iio_buffer_write_length)
> -
> -#define IIO_BUFFER_ENABLE_ATTR DEVICE_ATTR(enable, S_IRUGO | S_IWUSR,	\
> -					   iio_buffer_show_enable,	\
> -					   iio_buffer_store_enable)
> -
>  bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev,
>  	const unsigned long *mask);
>  
>