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