text: /* The industrial I/O core
   *
   *Copyright (c) 2008 Jonathan Cameron
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 as published by
   * the Free Software Foundation.
   *
   * General attributes
   */
  
  #ifndef _INDUSTRIAL_IO_SYSFS_H_
  #define _INDUSTRIAL_IO_SYSFS_H_
  
  struct iio_chan_spec;
  
  /**
   * struct iio_dev_attr - iio specific device attribute
   * @dev_attr:	underlying device attribute
   * @address:	associated register address
   * @l:		list head for maintaining list of dynamically created attrs.
   */
  struct iio_dev_attr {
  	struct device_attribute dev_attr;
  	u64 address;
  	struct list_head l;
  	struct iio_chan_spec const *c;
  };
  
  #define to_iio_dev_attr(_dev_attr)				\
  	container_of(_dev_attr, struct iio_dev_attr, dev_attr)
  
  ssize_t iio_read_const_attr(struct device *dev,
  			    struct device_attribute *attr,
  			    char *len);
  
  /**
   * struct iio_const_attr - constant device specific attribute
   *                         often used for things like available modes
   * @string:	attribute string
   * @dev_attr:	underlying device attribute
   */
  struct iio_const_attr {
  	const char *string;
  	struct device_attribute dev_attr;
  };
  
  #define to_iio_const_attr(_dev_attr) \
  	container_of(_dev_attr, struct iio_const_attr, dev_attr)
  
  /* Some attributes will be hard coded (device dependent) and not require an
     address, in these cases pass a negative */
  #define IIO_ATTR(_name, _mode, _show, _store, _addr)		\
  	{ .dev_attr = __ATTR(_name, _mode, _show, _store),	\
  	  .address = _addr }
  
  #define IIO_DEVICE_ATTR(_name, _mode, _show, _store, _addr)	\
  	struct iio_dev_attr iio_dev_attr_##_name		\
  	= IIO_ATTR(_name, _mode, _show, _store, _addr)
  
  #define IIO_DEVICE_ATTR_NAMED(_vname, _name, _mode, _show, _store, _addr) \
  	struct iio_dev_attr iio_dev_attr_##_vname			\
  	= IIO_ATTR(_name, _mode, _show, _store, _addr)
  
  #define IIO_CONST_ATTR(_name, _string)					\
  	struct iio_const_attr iio_const_attr_##_name			\
  	= { .string = _string,						\
  	    .dev_attr = __ATTR(_name, S_IRUGO, iio_read_const_attr, NULL)}
  
  #define IIO_CONST_ATTR_NAMED(_vname, _name, _string)			\
  	struct iio_const_attr iio_const_attr_##_vname			\
  	= { .string = _string,						\
  	    .dev_attr = __ATTR(_name, S_IRUGO, iio_read_const_attr, NULL)}
  
  /* Generic attributes of onetype or another */
  /**
   * IIO_DEV_ATTR_RESET: resets the device
   **/
  #define IIO_DEV_ATTR_RESET(_store)			\
  	IIO_DEVICE_ATTR(reset, S_IWUSR, NULL, _store, 0)
  
  /**
   * IIO_DEV_ATTR_SAMP_FREQ - sets any internal clock frequency
   * @_mode: sysfs file mode/permissions
   * @_show: output method for the attribute
   * @_store: input method for the attribute
   **/
  #define IIO_DEV_ATTR_SAMP_FREQ(_mode, _show, _store)			\
  	IIO_DEVICE_ATTR(sampling_frequency, _mode, _show, _store, 0)
  
  /**
   * IIO_DEV_ATTR_SAMP_FREQ_AVAIL - list available sampling frequencies
   * @_show: output method for the attribute
   *
   * May be mode dependent on some devices
   **/
  #define IIO_DEV_ATTR_SAMP_FREQ_AVAIL(_show)				\
  	IIO_DEVICE_ATTR(sampling_frequency_available, S_IRUGO, _show, NULL, 0)
  /**
   * IIO_CONST_ATTR_AVAIL_SAMP_FREQ - list available sampling frequencies
   * @_string: frequency string for the attribute
   *
   * Constant version
   **/
  #define IIO_CONST_ATTR_SAMP_FREQ_AVAIL(_string)			\
  	IIO_CONST_ATTR(sampling_frequency_available, _string)
  
  #define IIO_DEV_ATTR_TEMP_RAW(_show)			\
  	IIO_DEVICE_ATTR(in_temp_raw, S_IRUGO, _show, NULL, 0)
  
  #define IIO_CONST_ATTR_TEMP_OFFSET(_string)		\
  	IIO_CONST_ATTR(in_temp_offset, _string)
  
  #define IIO_CONST_ATTR_TEMP_SCALE(_string)		\
  	IIO_CONST_ATTR(in_temp_scale, _string)
  
  #endif /* _INDUSTRIAL_IO_SYSFS_H_ */
  