1  /* SPDX-License-Identifier: GPL-2.0 */
2  /* Copyright (C) 2020 ROHM Semiconductors */
3  
4  #ifndef LINEAR_RANGE_H
5  #define LINEAR_RANGE_H
6  
7  #include <linux/types.h>
8  
9  /**
10   * struct linear_range - table of selector - value pairs
11   *
12   * Define a lookup-table for range of values. Intended to help when looking
13   * for a register value matching certaing physical measure (like voltage).
14   * Usable when increment of one in register always results a constant increment
15   * of the physical measure (like voltage).
16   *
17   * @min:  Lowest value in range
18   * @min_sel: Lowest selector for range
19   * @max_sel: Highest selector for range
20   * @step: Value step size
21   */
22  struct linear_range {
23  	unsigned int min;
24  	unsigned int min_sel;
25  	unsigned int max_sel;
26  	unsigned int step;
27  };
28  
29  #define LINEAR_RANGE(_min, _min_sel, _max_sel, _step)		\
30  	{							\
31  		.min = _min,					\
32  		.min_sel = _min_sel,				\
33  		.max_sel = _max_sel,				\
34  		.step = _step,					\
35  	}
36  
37  #define LINEAR_RANGE_IDX(_idx, _min, _min_sel, _max_sel, _step)	\
38  	[_idx] = LINEAR_RANGE(_min, _min_sel, _max_sel, _step)
39  
40  unsigned int linear_range_values_in_range(const struct linear_range *r);
41  unsigned int linear_range_values_in_range_array(const struct linear_range *r,
42  						int ranges);
43  unsigned int linear_range_get_max_value(const struct linear_range *r);
44  
45  int linear_range_get_value(const struct linear_range *r, unsigned int selector,
46  			   unsigned int *val);
47  int linear_range_get_value_array(const struct linear_range *r, int ranges,
48  				 unsigned int selector, unsigned int *val);
49  int linear_range_get_selector_low(const struct linear_range *r,
50  				  unsigned int val, unsigned int *selector,
51  				  bool *found);
52  int linear_range_get_selector_high(const struct linear_range *r,
53  				   unsigned int val, unsigned int *selector,
54  				   bool *found);
55  void linear_range_get_selector_within(const struct linear_range *r,
56  				      unsigned int val, unsigned int *selector);
57  int linear_range_get_selector_low_array(const struct linear_range *r,
58  					int ranges, unsigned int val,
59  					unsigned int *selector, bool *found);
60  
61  #endif
62