1 /* SPDX-License-Identifier: GPL-2.0-only */ 1
2 /* gain-time-scale conversion helpers for IIO
3 *
4 * Copyright (c) 2023 Matti Vaittinen <mazzies
5 */
6
7 #ifndef __IIO_GTS_HELPER__
8 #define __IIO_GTS_HELPER__
9
10 #include <linux/types.h>
11
12 struct device;
13
14 /**
15 * struct iio_gain_sel_pair - gain - selector
16 *
17 * In many cases devices like light sensors al
18 * (gain) using a register interface. This str
19 * and corresponding selector (register value)
20 *
21 * @gain: Gain (multiplication) value. G
22 * values are reserved for error
23 * @sel: Selector (usually register val
24 * NOTE: Only selectors >= 0 supp
25 */
26 struct iio_gain_sel_pair {
27 int gain;
28 int sel;
29 };
30
31 /**
32 * struct iio_itime_sel_mul - integration time
33 *
34 * In many cases devices like light sensors al
35 * collecting data. Typically this duration ha
36 * of measured values (gain). This structure d
37 * integration time and amplification as well
38 * (register value).
39 *
40 * An example could be a sensor allowing 50, 1
41 * respective multiplication values could be 5
42 * 200 mS => 4 and 400 mS => 8 assuming the im
43 * linear in a way that when collecting data f
44 * the data collection time caused value 2X et
45 *
46 * @time_us: Integration time in microsecon
47 * negative values are reserved f
48 * @sel: Selector (usually register val
49 * NOTE: Only selectors >= 0 supp
50 * @mul: Multiplication to the values c
51 * NOTE: Only multipliers > 0 sup
52 */
53 struct iio_itime_sel_mul {
54 int time_us;
55 int sel;
56 int mul;
57 };
58
59 struct iio_gts {
60 u64 max_scale;
61 const struct iio_gain_sel_pair *hwgain
62 int num_hwgain;
63 const struct iio_itime_sel_mul *itime_
64 int num_itime;
65 int **per_time_avail_scale_tables;
66 int *avail_all_scales_table;
67 int num_avail_all_scales;
68 int *avail_time_tables;
69 int num_avail_time_tables;
70 };
71
72 #define GAIN_SCALE_GAIN(_gain, _sel)
73 {
74 .gain = (_gain),
75 .sel = (_sel),
76 }
77
78 #define GAIN_SCALE_ITIME_US(_itime, _sel, _mul
79 {
80 .time_us = (_itime),
81 .sel = (_sel),
82 .mul = (_mul),
83 }
84
85 static inline const struct iio_itime_sel_mul *
86 iio_gts_find_itime_by_time(struct iio_gts *gts
87 {
88 int i;
89
90 if (!gts->num_itime)
91 return NULL;
92
93 for (i = 0; i < gts->num_itime; i++)
94 if (gts->itime_table[i].time_u
95 return >s->itime_tab
96
97 return NULL;
98 }
99
100 static inline const struct iio_itime_sel_mul *
101 iio_gts_find_itime_by_sel(struct iio_gts *gts,
102 {
103 int i;
104
105 for (i = 0; i < gts->num_itime; i++)
106 if (gts->itime_table[i].sel ==
107 return >s->itime_tab
108
109 return NULL;
110 }
111
112 int devm_iio_init_iio_gts(struct device *dev,
113 const struct iio_gai
114 const struct iio_iti
115 struct iio_gts *gts)
116 /**
117 * iio_gts_find_int_time_by_sel - find integra
118 * @gts: Gain time scale descriptor
119 * @sel: selector for which matching in
120 *
121 * Return: integration time matching give
122 * integration time was not found
123 */
124 static inline int iio_gts_find_int_time_by_sel
125 {
126 const struct iio_itime_sel_mul *itime;
127
128 itime = iio_gts_find_itime_by_sel(gts,
129 if (!itime)
130 return -EINVAL;
131
132 return itime->time_us;
133 }
134
135 /**
136 * iio_gts_find_sel_by_int_time - find selecto
137 * @gts: Gain time scale descriptor
138 * @time: Integration time for which mat
139 *
140 * Return: a selector matching given inte
141 * selector was not found.
142 */
143 static inline int iio_gts_find_sel_by_int_time
144 {
145 const struct iio_itime_sel_mul *itime;
146
147 itime = iio_gts_find_itime_by_time(gts
148 if (!itime)
149 return -EINVAL;
150
151 return itime->sel;
152 }
153
154 /**
155 * iio_gts_valid_time - check if given integra
156 * @gts: Gain time scale descriptor
157 * @time_us: Integration time to check
158 *
159 * Return: True if given time is supporte
160 */
161 static inline bool iio_gts_valid_time(struct i
162 {
163 return iio_gts_find_itime_by_time(gts,
164 }
165
166 int iio_gts_find_sel_by_gain(struct iio_gts *g
167
168 /**
169 * iio_gts_valid_gain - check if given HW-gain
170 * @gts: Gain time scale descriptor
171 * @gain: HW-gain to check
172 *
173 * Return: True if given time is supporte
174 */
175 static inline bool iio_gts_valid_gain(struct i
176 {
177 return iio_gts_find_sel_by_gain(gts, g
178 }
179
180 int iio_find_closest_gain_low(struct iio_gts *
181 int iio_gts_find_gain_by_sel(struct iio_gts *g
182 int iio_gts_get_min_gain(struct iio_gts *gts);
183 int iio_gts_find_int_time_by_sel(struct iio_gt
184 int iio_gts_find_sel_by_int_time(struct iio_gt
185
186 int iio_gts_total_gain_to_scale(struct iio_gts
187 int *scale_int
188 int iio_gts_find_gain_sel_for_scale_using_time
189
190
191 int iio_gts_get_scale(struct iio_gts *gts, int
192 int *scale_nano);
193 int iio_gts_find_new_gain_sel_by_old_gain_time
194
195
196 int iio_gts_find_new_gain_by_old_gain_time(str
197 int
198 int
199 int iio_gts_avail_times(struct iio_gts *gts,
200 int *length);
201 int iio_gts_all_avail_scales(struct iio_gts *g
202 int *length);
203 int iio_gts_avail_scales_for_time(struct iio_g
204 const int **
205
206 #endif
207
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