1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Unit tests for IIO light sensor gain-time-scale helpers
3 *
4 * Copyright (c) 2023 Matti Vaittinen <mazziesaccount@gmail.com>
5 */
6
7 #include <kunit/device.h>
8 #include <kunit/test.h>
9 #include <linux/device.h>
10 #include <linux/iio/iio-gts-helper.h>
11 #include <linux/iio/types.h>
12
13 /*
14 * Please, read the "rant" from the top of the lib/test_linear_ranges.c if
15 * you see a line of helper code which is not being tested.
16 *
17 * Then, please look at the line which is not being tested. Is this line
18 * somehow unusually complex? If answer is "no", then chances are that the
19 * "development inertia" caused by adding a test exceeds the benefits.
20 *
21 * If yes, then adding a test is probably a good idea but please stop for a
22 * moment and consider the effort of changing all the tests when code gets
23 * refactored. Eventually it neeeds to be.
24 */
25
26 #define TEST_TSEL_50 1
27 #define TEST_TSEL_X_MIN TEST_TSEL_50
28 #define TEST_TSEL_100 0
29 #define TEST_TSEL_200 2
30 #define TEST_TSEL_400 4
31 #define TEST_TSEL_X_MAX TEST_TSEL_400
32
33 #define TEST_GSEL_1 0x00
34 #define TEST_GSEL_X_MIN TEST_GSEL_1
35 #define TEST_GSEL_4 0x08
36 #define TEST_GSEL_16 0x0a
37 #define TEST_GSEL_32 0x0b
38 #define TEST_GSEL_64 0x0c
39 #define TEST_GSEL_256 0x18
40 #define TEST_GSEL_512 0x19
41 #define TEST_GSEL_1024 0x1a
42 #define TEST_GSEL_2048 0x1b
43 #define TEST_GSEL_4096 0x1c
44 #define TEST_GSEL_X_MAX TEST_GSEL_4096
45
46 #define TEST_SCALE_1X 64
47 #define TEST_SCALE_MIN_X TEST_SCALE_1X
48 #define TEST_SCALE_2X 32
49 #define TEST_SCALE_4X 16
50 #define TEST_SCALE_8X 8
51 #define TEST_SCALE_16X 4
52 #define TEST_SCALE_32X 2
53 #define TEST_SCALE_64X 1
54
55 #define TEST_SCALE_NANO_128X 500000000
56 #define TEST_SCALE_NANO_256X 250000000
57 #define TEST_SCALE_NANO_512X 125000000
58 #define TEST_SCALE_NANO_1024X 62500000
59 #define TEST_SCALE_NANO_2048X 31250000
60 #define TEST_SCALE_NANO_4096X 15625000
61 #define TEST_SCALE_NANO_4096X2 7812500
62 #define TEST_SCALE_NANO_4096X4 3906250
63 #define TEST_SCALE_NANO_4096X8 1953125
64
65 #define TEST_SCALE_NANO_MAX_X TEST_SCALE_NANO_4096X8
66
67 /*
68 * Can't have this allocated from stack because the kunit clean-up will
69 * happen only after the test function has already gone
70 */
71 static struct iio_gts gts;
72
73 /* Keep the gain and time tables unsorted to test the sorting */
74 static const struct iio_gain_sel_pair gts_test_gains[] = {
75 GAIN_SCALE_GAIN(1, TEST_GSEL_1),
76 GAIN_SCALE_GAIN(4, TEST_GSEL_4),
77 GAIN_SCALE_GAIN(16, TEST_GSEL_16),
78 GAIN_SCALE_GAIN(32, TEST_GSEL_32),
79 GAIN_SCALE_GAIN(64, TEST_GSEL_64),
80 GAIN_SCALE_GAIN(256, TEST_GSEL_256),
81 GAIN_SCALE_GAIN(512, TEST_GSEL_512),
82 GAIN_SCALE_GAIN(1024, TEST_GSEL_1024),
83 GAIN_SCALE_GAIN(4096, TEST_GSEL_4096),
84 GAIN_SCALE_GAIN(2048, TEST_GSEL_2048),
85 #define HWGAIN_MAX 4096
86 };
87
88 static const struct iio_itime_sel_mul gts_test_itimes[] = {
89 GAIN_SCALE_ITIME_US(100 * 1000, TEST_TSEL_100, 2),
90 GAIN_SCALE_ITIME_US(400 * 1000, TEST_TSEL_400, 8),
91 GAIN_SCALE_ITIME_US(400 * 1000, TEST_TSEL_400, 8),
92 GAIN_SCALE_ITIME_US(50 * 1000, TEST_TSEL_50, 1),
93 GAIN_SCALE_ITIME_US(200 * 1000, TEST_TSEL_200, 4),
94 #define TIMEGAIN_MAX 8
95 };
96 #define TOTAL_GAIN_MAX (HWGAIN_MAX * TIMEGAIN_MAX)
97 #define IIO_GTS_TEST_DEV "iio-gts-test-dev"
98
__test_init_iio_gain_scale(struct kunit * test,struct iio_gts * gts,const struct iio_gain_sel_pair * g_table,int num_g,const struct iio_itime_sel_mul * i_table,int num_i)99 static struct device *__test_init_iio_gain_scale(struct kunit *test,
100 struct iio_gts *gts, const struct iio_gain_sel_pair *g_table,
101 int num_g, const struct iio_itime_sel_mul *i_table, int num_i)
102 {
103 struct device *dev;
104 int ret;
105
106 dev = kunit_device_register(test, IIO_GTS_TEST_DEV);
107
108 KUNIT_EXPECT_NOT_ERR_OR_NULL(test, dev);
109 if (IS_ERR_OR_NULL(dev))
110 return NULL;
111
112 ret = devm_iio_init_iio_gts(dev, TEST_SCALE_1X, 0, g_table, num_g,
113 i_table, num_i, gts);
114 KUNIT_EXPECT_EQ(test, 0, ret);
115 if (ret)
116 return NULL;
117
118 return dev;
119 }
120
121 #define test_init_iio_gain_scale(test, gts) \
122 __test_init_iio_gain_scale(test, gts, gts_test_gains, \
123 ARRAY_SIZE(gts_test_gains), gts_test_itimes, \
124 ARRAY_SIZE(gts_test_itimes))
125
test_init_iio_gts_invalid(struct kunit * test)126 static void test_init_iio_gts_invalid(struct kunit *test)
127 {
128 struct device *dev;
129 int ret;
130 const struct iio_itime_sel_mul itimes_neg[] = {
131 GAIN_SCALE_ITIME_US(-10, TEST_TSEL_400, 8),
132 GAIN_SCALE_ITIME_US(200 * 1000, TEST_TSEL_200, 4),
133 };
134 const struct iio_gain_sel_pair gains_neg[] = {
135 GAIN_SCALE_GAIN(1, TEST_GSEL_1),
136 GAIN_SCALE_GAIN(2, TEST_GSEL_4),
137 GAIN_SCALE_GAIN(-2, TEST_GSEL_16),
138 };
139 /* 55555 * 38656 = 2147534080 => overflows 32bit int */
140 const struct iio_itime_sel_mul itimes_overflow[] = {
141 GAIN_SCALE_ITIME_US(400 * 1000, TEST_TSEL_400, 55555),
142 GAIN_SCALE_ITIME_US(200 * 1000, TEST_TSEL_200, 4),
143 };
144 const struct iio_gain_sel_pair gains_overflow[] = {
145 GAIN_SCALE_GAIN(1, TEST_GSEL_1),
146 GAIN_SCALE_GAIN(2, TEST_GSEL_4),
147 GAIN_SCALE_GAIN(38656, TEST_GSEL_16),
148 };
149
150 dev = kunit_device_register(test, IIO_GTS_TEST_DEV);
151 KUNIT_EXPECT_NOT_ERR_OR_NULL(test, dev);
152 if (!dev)
153 return;
154
155 /* Ok gains, negative time */
156 ret = devm_iio_init_iio_gts(dev, TEST_SCALE_1X, 0, gts_test_gains,
157 ARRAY_SIZE(gts_test_gains), itimes_neg,
158 ARRAY_SIZE(itimes_neg), >s);
159 KUNIT_EXPECT_EQ(test, -EINVAL, ret);
160
161 /* Ok times, negative gain */
162 ret = devm_iio_init_iio_gts(dev, TEST_SCALE_1X, 0, gains_neg,
163 ARRAY_SIZE(gains_neg), gts_test_itimes,
164 ARRAY_SIZE(gts_test_itimes), >s);
165 KUNIT_EXPECT_EQ(test, -EINVAL, ret);
166
167 /* gain * time overflow int */
168 ret = devm_iio_init_iio_gts(dev, TEST_SCALE_1X, 0, gains_overflow,
169 ARRAY_SIZE(gains_overflow), itimes_overflow,
170 ARRAY_SIZE(itimes_overflow), >s);
171 KUNIT_EXPECT_EQ(test, -EOVERFLOW, ret);
172 }
173
test_iio_gts_find_gain_for_scale_using_time(struct kunit * test)174 static void test_iio_gts_find_gain_for_scale_using_time(struct kunit *test)
175 {
176 struct device *dev;
177 int ret, gain_sel;
178
179 dev = test_init_iio_gain_scale(test, >s);
180 if (!dev)
181 return;
182
183 ret = iio_gts_find_gain_sel_for_scale_using_time(>s, TEST_TSEL_100,
184 TEST_SCALE_8X, 0, &gain_sel);
185 /*
186 * Meas time 100 => gain by time 2x
187 * TEST_SCALE_8X matches total gain 8x
188 * => required HWGAIN 4x
189 */
190 KUNIT_EXPECT_EQ(test, 0, ret);
191 KUNIT_EXPECT_EQ(test, TEST_GSEL_4, gain_sel);
192
193 ret = iio_gts_find_gain_sel_for_scale_using_time(>s, TEST_TSEL_200, 0,
194 TEST_SCALE_NANO_256X, &gain_sel);
195 /*
196 * Meas time 200 => gain by time 4x
197 * TEST_SCALE_256X matches total gain 256x
198 * => required HWGAIN 256/4 => 64x
199 */
200 KUNIT_EXPECT_EQ(test, 0, ret);
201 KUNIT_EXPECT_EQ(test, TEST_GSEL_64, gain_sel);
202
203 /* Min time, Min gain */
204 ret = iio_gts_find_gain_sel_for_scale_using_time(>s, TEST_TSEL_X_MIN,
205 TEST_SCALE_MIN_X, 0, &gain_sel);
206 KUNIT_EXPECT_EQ(test, 0, ret);
207 KUNIT_EXPECT_EQ(test, TEST_GSEL_1, gain_sel);
208
209 /* Max time, Max gain */
210 ret = iio_gts_find_gain_sel_for_scale_using_time(>s, TEST_TSEL_X_MAX,
211 0, TEST_SCALE_NANO_MAX_X, &gain_sel);
212 KUNIT_EXPECT_EQ(test, 0, ret);
213 KUNIT_EXPECT_EQ(test, TEST_GSEL_4096, gain_sel);
214
215 ret = iio_gts_find_gain_sel_for_scale_using_time(>s, TEST_TSEL_100, 0,
216 TEST_SCALE_NANO_256X, &gain_sel);
217 /*
218 * Meas time 100 => gain by time 2x
219 * TEST_SCALE_256X matches total gain 256x
220 * => required HWGAIN 256/2 => 128x (not in gain-table - unsupported)
221 */
222 KUNIT_EXPECT_NE(test, 0, ret);
223
224 ret = iio_gts_find_gain_sel_for_scale_using_time(>s, TEST_TSEL_200, 0,
225 TEST_SCALE_NANO_MAX_X, &gain_sel);
226 /* We can't reach the max gain with integration time smaller than MAX */
227 KUNIT_EXPECT_NE(test, 0, ret);
228
229 ret = iio_gts_find_gain_sel_for_scale_using_time(>s, TEST_TSEL_50, 0,
230 TEST_SCALE_NANO_MAX_X, &gain_sel);
231 /* We can't reach the max gain with integration time smaller than MAX */
232 KUNIT_EXPECT_NE(test, 0, ret);
233 }
234
test_iio_gts_find_new_gain_sel_by_old_gain_time(struct kunit * test)235 static void test_iio_gts_find_new_gain_sel_by_old_gain_time(struct kunit *test)
236 {
237 struct device *dev;
238 int ret, old_gain, new_gain, old_time_sel, new_time_sel;
239
240 dev = test_init_iio_gain_scale(test, >s);
241 if (!dev)
242 return;
243
244 old_gain = 32;
245 old_time_sel = TEST_TSEL_200;
246 new_time_sel = TEST_TSEL_400;
247
248 ret = iio_gts_find_new_gain_sel_by_old_gain_time(>s, old_gain,
249 old_time_sel, new_time_sel, &new_gain);
250 KUNIT_EXPECT_EQ(test, 0, ret);
251 /*
252 * Doubling the integration time doubles the total gain - so old
253 * (hw)gain must be divided by two to compensate. => 32 / 2 => 16
254 */
255 KUNIT_EXPECT_EQ(test, 16, new_gain);
256
257 old_gain = 4;
258 old_time_sel = TEST_TSEL_50;
259 new_time_sel = TEST_TSEL_200;
260 ret = iio_gts_find_new_gain_sel_by_old_gain_time(>s, old_gain,
261 old_time_sel, new_time_sel, &new_gain);
262 KUNIT_EXPECT_EQ(test, 0, ret);
263 /*
264 * gain by time 1x => 4x - (hw)gain 4x => 1x
265 */
266 KUNIT_EXPECT_EQ(test, 1, new_gain);
267
268 old_gain = 512;
269 old_time_sel = TEST_TSEL_400;
270 new_time_sel = TEST_TSEL_50;
271 ret = iio_gts_find_new_gain_sel_by_old_gain_time(>s, old_gain,
272 old_time_sel, new_time_sel, &new_gain);
273 KUNIT_EXPECT_EQ(test, 0, ret);
274 /*
275 * gain by time 8x => 1x - (hw)gain 512x => 4096x)
276 */
277 KUNIT_EXPECT_EQ(test, 4096, new_gain);
278
279 /* Unsupported gain 2x */
280 old_gain = 4;
281 old_time_sel = TEST_TSEL_200;
282 new_time_sel = TEST_TSEL_400;
283 ret = iio_gts_find_new_gain_sel_by_old_gain_time(>s, old_gain,
284 old_time_sel, new_time_sel, &new_gain);
285 KUNIT_EXPECT_NE(test, 0, ret);
286
287 /* Too small gain */
288 old_gain = 4;
289 old_time_sel = TEST_TSEL_50;
290 new_time_sel = TEST_TSEL_400;
291 ret = iio_gts_find_new_gain_sel_by_old_gain_time(>s, old_gain,
292 old_time_sel, new_time_sel, &new_gain);
293 KUNIT_EXPECT_NE(test, 0, ret);
294
295 /* Too big gain */
296 old_gain = 1024;
297 old_time_sel = TEST_TSEL_400;
298 new_time_sel = TEST_TSEL_50;
299 ret = iio_gts_find_new_gain_sel_by_old_gain_time(>s, old_gain,
300 old_time_sel, new_time_sel, &new_gain);
301 KUNIT_EXPECT_NE(test, 0, ret);
302
303 }
304
test_iio_find_closest_gain_low(struct kunit * test)305 static void test_iio_find_closest_gain_low(struct kunit *test)
306 {
307 struct device *dev;
308 bool in_range;
309 int ret;
310
311 const struct iio_gain_sel_pair gts_test_gains_gain_low[] = {
312 GAIN_SCALE_GAIN(4, TEST_GSEL_4),
313 GAIN_SCALE_GAIN(16, TEST_GSEL_16),
314 GAIN_SCALE_GAIN(32, TEST_GSEL_32),
315 };
316
317 dev = test_init_iio_gain_scale(test, >s);
318 if (!dev)
319 return;
320
321 ret = iio_find_closest_gain_low(>s, 2, &in_range);
322 KUNIT_EXPECT_EQ(test, 1, ret);
323 KUNIT_EXPECT_EQ(test, true, in_range);
324
325 ret = iio_find_closest_gain_low(>s, 1, &in_range);
326 KUNIT_EXPECT_EQ(test, 1, ret);
327 KUNIT_EXPECT_EQ(test, true, in_range);
328
329 ret = iio_find_closest_gain_low(>s, 4095, &in_range);
330 KUNIT_EXPECT_EQ(test, 2048, ret);
331 KUNIT_EXPECT_EQ(test, true, in_range);
332
333 ret = iio_find_closest_gain_low(>s, 4097, &in_range);
334 KUNIT_EXPECT_EQ(test, 4096, ret);
335 KUNIT_EXPECT_EQ(test, false, in_range);
336
337 kunit_device_unregister(test, dev);
338
339 dev = __test_init_iio_gain_scale(test, >s, gts_test_gains_gain_low,
340 ARRAY_SIZE(gts_test_gains_gain_low),
341 gts_test_itimes, ARRAY_SIZE(gts_test_itimes));
342 if (!dev)
343 return;
344
345 ret = iio_find_closest_gain_low(>s, 3, &in_range);
346 KUNIT_EXPECT_EQ(test, -EINVAL, ret);
347 KUNIT_EXPECT_EQ(test, false, in_range);
348 }
349
test_iio_gts_total_gain_to_scale(struct kunit * test)350 static void test_iio_gts_total_gain_to_scale(struct kunit *test)
351 {
352 struct device *dev;
353 int ret, scale_int, scale_nano;
354
355 dev = test_init_iio_gain_scale(test, >s);
356 if (!dev)
357 return;
358
359 ret = iio_gts_total_gain_to_scale(>s, 1, &scale_int, &scale_nano);
360 KUNIT_EXPECT_EQ(test, 0, ret);
361 KUNIT_EXPECT_EQ(test, TEST_SCALE_1X, scale_int);
362 KUNIT_EXPECT_EQ(test, 0, scale_nano);
363
364 ret = iio_gts_total_gain_to_scale(>s, 1, &scale_int, &scale_nano);
365 KUNIT_EXPECT_EQ(test, 0, ret);
366 KUNIT_EXPECT_EQ(test, TEST_SCALE_1X, scale_int);
367 KUNIT_EXPECT_EQ(test, 0, scale_nano);
368
369 ret = iio_gts_total_gain_to_scale(>s, 4096 * 8, &scale_int,
370 &scale_nano);
371 KUNIT_EXPECT_EQ(test, 0, ret);
372 KUNIT_EXPECT_EQ(test, 0, scale_int);
373 KUNIT_EXPECT_EQ(test, TEST_SCALE_NANO_4096X8, scale_nano);
374 }
375
test_iio_gts_chk_times(struct kunit * test,const int * vals)376 static void test_iio_gts_chk_times(struct kunit *test, const int *vals)
377 {
378 static const int expected[] = {0, 50000, 0, 100000, 0, 200000, 0, 400000};
379 int i;
380
381 for (i = 0; i < ARRAY_SIZE(expected); i++)
382 KUNIT_EXPECT_EQ(test, expected[i], vals[i]);
383 }
384
test_iio_gts_chk_scales_all(struct kunit * test,struct iio_gts * gts,const int * vals,int len)385 static void test_iio_gts_chk_scales_all(struct kunit *test, struct iio_gts *gts,
386 const int *vals, int len)
387 {
388 static const int gains[] = {1, 2, 4, 8, 16, 32, 64, 128, 256, 512,
389 1024, 2048, 4096, 4096 * 2, 4096 * 4,
390 4096 * 8};
391 int expected[ARRAY_SIZE(gains) * 2];
392 int i, ret;
393 int exp_len = ARRAY_SIZE(gains) * 2;
394
395 KUNIT_EXPECT_EQ(test, exp_len, len);
396 if (len != exp_len)
397 return;
398
399 for (i = 0; i < ARRAY_SIZE(gains); i++) {
400 ret = iio_gts_total_gain_to_scale(gts, gains[i],
401 &expected[2 * i],
402 &expected[2 * i + 1]);
403 KUNIT_EXPECT_EQ(test, 0, ret);
404 if (ret)
405 return;
406 }
407
408 for (i = 0; i < ARRAY_SIZE(expected); i++)
409 KUNIT_EXPECT_EQ(test, expected[i], vals[i]);
410 }
411
test_iio_gts_chk_scales_t200(struct kunit * test,struct iio_gts * gts,const int * vals,int len)412 static void test_iio_gts_chk_scales_t200(struct kunit *test, struct iio_gts *gts,
413 const int *vals, int len)
414 {
415 /* The gain caused by time 200 is 4x */
416 static const int gains[] = {
417 1 * 4,
418 4 * 4,
419 16 * 4,
420 32 * 4,
421 64 * 4,
422 256 * 4,
423 512 * 4,
424 1024 * 4,
425 2048 * 4,
426 4096 * 4
427 };
428 int expected[ARRAY_SIZE(gains) * 2];
429 int i, ret;
430
431 KUNIT_EXPECT_EQ(test, 2 * ARRAY_SIZE(gains), len);
432 if (len < 2 * ARRAY_SIZE(gains))
433 return;
434
435 for (i = 0; i < ARRAY_SIZE(gains); i++) {
436 ret = iio_gts_total_gain_to_scale(gts, gains[i],
437 &expected[2 * i],
438 &expected[2 * i + 1]);
439 KUNIT_EXPECT_EQ(test, 0, ret);
440 if (ret)
441 return;
442 }
443
444 for (i = 0; i < ARRAY_SIZE(expected); i++)
445 KUNIT_EXPECT_EQ(test, expected[i], vals[i]);
446 }
447
test_iio_gts_avail_test(struct kunit * test)448 static void test_iio_gts_avail_test(struct kunit *test)
449 {
450 struct device *dev;
451 int ret;
452 int type, len;
453 const int *vals;
454
455 dev = test_init_iio_gain_scale(test, >s);
456 if (!dev)
457 return;
458
459 /* test table building for times and iio_gts_avail_times() */
460 ret = iio_gts_avail_times(>s, &vals, &type, &len);
461 KUNIT_EXPECT_EQ(test, IIO_AVAIL_LIST, ret);
462 if (ret)
463 return;
464
465 KUNIT_EXPECT_EQ(test, IIO_VAL_INT_PLUS_MICRO, type);
466 KUNIT_EXPECT_EQ(test, 8, len);
467 if (len < 8)
468 return;
469
470 test_iio_gts_chk_times(test, vals);
471
472 /* Test table building for all scales and iio_gts_all_avail_scales() */
473 ret = iio_gts_all_avail_scales(>s, &vals, &type, &len);
474 KUNIT_EXPECT_EQ(test, IIO_AVAIL_LIST, ret);
475 if (ret)
476 return;
477
478 KUNIT_EXPECT_EQ(test, IIO_VAL_INT_PLUS_NANO, type);
479
480 test_iio_gts_chk_scales_all(test, >s, vals, len);
481
482 /*
483 * Test table building for scales/time and
484 * iio_gts_avail_scales_for_time()
485 */
486 ret = iio_gts_avail_scales_for_time(>s, 200000, &vals, &type, &len);
487 KUNIT_EXPECT_EQ(test, IIO_AVAIL_LIST, ret);
488 if (ret)
489 return;
490
491 KUNIT_EXPECT_EQ(test, IIO_VAL_INT_PLUS_NANO, type);
492 test_iio_gts_chk_scales_t200(test, >s, vals, len);
493 }
494
495 static struct kunit_case iio_gts_test_cases[] = {
496 KUNIT_CASE(test_init_iio_gts_invalid),
497 KUNIT_CASE(test_iio_gts_find_gain_for_scale_using_time),
498 KUNIT_CASE(test_iio_gts_find_new_gain_sel_by_old_gain_time),
499 KUNIT_CASE(test_iio_find_closest_gain_low),
500 KUNIT_CASE(test_iio_gts_total_gain_to_scale),
501 KUNIT_CASE(test_iio_gts_avail_test),
502 {}
503 };
504
505 static struct kunit_suite iio_gts_test_suite = {
506 .name = "iio-gain-time-scale",
507 .test_cases = iio_gts_test_cases,
508 };
509
510 kunit_test_suite(iio_gts_test_suite);
511
512 MODULE_LICENSE("GPL");
513 MODULE_AUTHOR("Matti Vaittinen <mazziesaccount@gmail.com>");
514 MODULE_DESCRIPTION("Test IIO light sensor gain-time-scale helpers");
515 MODULE_IMPORT_NS("IIO_GTS_HELPER");
516