xref: /linux/drivers/iio/test/iio-test-gts.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
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 static const struct iio_gain_sel_pair gts_test_gains[] = {
74 	GAIN_SCALE_GAIN(1, TEST_GSEL_1),
75 	GAIN_SCALE_GAIN(4, TEST_GSEL_4),
76 	GAIN_SCALE_GAIN(16, TEST_GSEL_16),
77 	GAIN_SCALE_GAIN(32, TEST_GSEL_32),
78 	GAIN_SCALE_GAIN(64, TEST_GSEL_64),
79 	GAIN_SCALE_GAIN(256, TEST_GSEL_256),
80 	GAIN_SCALE_GAIN(512, TEST_GSEL_512),
81 	GAIN_SCALE_GAIN(1024, TEST_GSEL_1024),
82 	GAIN_SCALE_GAIN(2048, TEST_GSEL_2048),
83 	GAIN_SCALE_GAIN(4096, TEST_GSEL_4096),
84 #define HWGAIN_MAX 4096
85 };
86 
87 static const struct iio_itime_sel_mul gts_test_itimes[] = {
88 	GAIN_SCALE_ITIME_US(400 * 1000, TEST_TSEL_400, 8),
89 	GAIN_SCALE_ITIME_US(200 * 1000, TEST_TSEL_200, 4),
90 	GAIN_SCALE_ITIME_US(100 * 1000, TEST_TSEL_100, 2),
91 	GAIN_SCALE_ITIME_US(50 * 1000, TEST_TSEL_50, 1),
92 #define TIMEGAIN_MAX 8
93 };
94 #define TOTAL_GAIN_MAX	(HWGAIN_MAX * TIMEGAIN_MAX)
95 #define IIO_GTS_TEST_DEV "iio-gts-test-dev"
96 
97 static struct device *__test_init_iio_gain_scale(struct kunit *test,
98 		struct iio_gts *gts, const struct iio_gain_sel_pair *g_table,
99 		int num_g, const struct iio_itime_sel_mul *i_table, int num_i)
100 {
101 	struct device *dev;
102 	int ret;
103 
104 	dev = kunit_device_register(test, IIO_GTS_TEST_DEV);
105 
106 	KUNIT_EXPECT_NOT_ERR_OR_NULL(test, dev);
107 	if (IS_ERR_OR_NULL(dev))
108 		return NULL;
109 
110 	ret = devm_iio_init_iio_gts(dev, TEST_SCALE_1X, 0, g_table, num_g,
111 				    i_table, num_i, gts);
112 	KUNIT_EXPECT_EQ(test, 0, ret);
113 	if (ret)
114 		return NULL;
115 
116 	return dev;
117 }
118 
119 #define test_init_iio_gain_scale(test, gts)	\
120 	__test_init_iio_gain_scale(test, gts, gts_test_gains, \
121 				   ARRAY_SIZE(gts_test_gains), gts_test_itimes, \
122 				   ARRAY_SIZE(gts_test_itimes))
123 
124 static void test_init_iio_gts_invalid(struct kunit *test)
125 {
126 	struct device *dev;
127 	int ret;
128 	const struct iio_itime_sel_mul itimes_neg[] = {
129 		GAIN_SCALE_ITIME_US(-10, TEST_TSEL_400, 8),
130 		GAIN_SCALE_ITIME_US(200 * 1000, TEST_TSEL_200, 4),
131 	};
132 	const struct iio_gain_sel_pair gains_neg[] = {
133 		GAIN_SCALE_GAIN(1, TEST_GSEL_1),
134 		GAIN_SCALE_GAIN(2, TEST_GSEL_4),
135 		GAIN_SCALE_GAIN(-2, TEST_GSEL_16),
136 	};
137 	/* 55555 * 38656 = 2147534080 => overflows 32bit int */
138 	const struct iio_itime_sel_mul itimes_overflow[] = {
139 		GAIN_SCALE_ITIME_US(400 * 1000, TEST_TSEL_400, 55555),
140 		GAIN_SCALE_ITIME_US(200 * 1000, TEST_TSEL_200, 4),
141 	};
142 	const struct iio_gain_sel_pair gains_overflow[] = {
143 		GAIN_SCALE_GAIN(1, TEST_GSEL_1),
144 		GAIN_SCALE_GAIN(2, TEST_GSEL_4),
145 		GAIN_SCALE_GAIN(38656, TEST_GSEL_16),
146 	};
147 
148 	dev = kunit_device_register(test, IIO_GTS_TEST_DEV);
149 	KUNIT_EXPECT_NOT_ERR_OR_NULL(test, dev);
150 	if (!dev)
151 		return;
152 
153 	/* Ok gains, negative time */
154 	ret = devm_iio_init_iio_gts(dev, TEST_SCALE_1X, 0, gts_test_gains,
155 				    ARRAY_SIZE(gts_test_gains), itimes_neg,
156 				    ARRAY_SIZE(itimes_neg), &gts);
157 	KUNIT_EXPECT_EQ(test, -EINVAL, ret);
158 
159 	/* Ok times, negative gain */
160 	ret = devm_iio_init_iio_gts(dev, TEST_SCALE_1X, 0, gains_neg,
161 				    ARRAY_SIZE(gains_neg), gts_test_itimes,
162 				    ARRAY_SIZE(gts_test_itimes), &gts);
163 	KUNIT_EXPECT_EQ(test, -EINVAL, ret);
164 
165 	/* gain * time overflow int */
166 	ret = devm_iio_init_iio_gts(dev, TEST_SCALE_1X, 0, gains_overflow,
167 				    ARRAY_SIZE(gains_overflow), itimes_overflow,
168 				    ARRAY_SIZE(itimes_overflow), &gts);
169 	KUNIT_EXPECT_EQ(test, -EOVERFLOW, ret);
170 }
171 
172 static void test_iio_gts_find_gain_for_scale_using_time(struct kunit *test)
173 {
174 	struct device *dev;
175 	int ret, gain_sel;
176 
177 	dev = test_init_iio_gain_scale(test, &gts);
178 	if (!dev)
179 		return;
180 
181 	ret = iio_gts_find_gain_sel_for_scale_using_time(&gts, TEST_TSEL_100,
182 						TEST_SCALE_8X, 0, &gain_sel);
183 	/*
184 	 * Meas time 100 => gain by time 2x
185 	 * TEST_SCALE_8X matches total gain 8x
186 	 * => required HWGAIN 4x
187 	 */
188 	KUNIT_EXPECT_EQ(test, 0, ret);
189 	KUNIT_EXPECT_EQ(test, TEST_GSEL_4, gain_sel);
190 
191 	ret = iio_gts_find_gain_sel_for_scale_using_time(&gts, TEST_TSEL_200, 0,
192 						TEST_SCALE_NANO_256X, &gain_sel);
193 	/*
194 	 * Meas time 200 => gain by time 4x
195 	 * TEST_SCALE_256X matches total gain 256x
196 	 * => required HWGAIN 256/4 => 64x
197 	 */
198 	KUNIT_EXPECT_EQ(test, 0, ret);
199 	KUNIT_EXPECT_EQ(test, TEST_GSEL_64, gain_sel);
200 
201 	/* Min time, Min gain */
202 	ret = iio_gts_find_gain_sel_for_scale_using_time(&gts, TEST_TSEL_X_MIN,
203 						TEST_SCALE_MIN_X, 0, &gain_sel);
204 	KUNIT_EXPECT_EQ(test, 0, ret);
205 	KUNIT_EXPECT_EQ(test, TEST_GSEL_1, gain_sel);
206 
207 	/* Max time, Max gain */
208 	ret = iio_gts_find_gain_sel_for_scale_using_time(&gts, TEST_TSEL_X_MAX,
209 					0, TEST_SCALE_NANO_MAX_X, &gain_sel);
210 	KUNIT_EXPECT_EQ(test, 0, ret);
211 	KUNIT_EXPECT_EQ(test, TEST_GSEL_4096, gain_sel);
212 
213 	ret = iio_gts_find_gain_sel_for_scale_using_time(&gts, TEST_TSEL_100, 0,
214 						TEST_SCALE_NANO_256X, &gain_sel);
215 	/*
216 	 * Meas time 100 => gain by time 2x
217 	 * TEST_SCALE_256X matches total gain 256x
218 	 * => required HWGAIN 256/2 => 128x (not in gain-table - unsupported)
219 	 */
220 	KUNIT_EXPECT_NE(test, 0, ret);
221 
222 	ret = iio_gts_find_gain_sel_for_scale_using_time(&gts, TEST_TSEL_200, 0,
223 						TEST_SCALE_NANO_MAX_X, &gain_sel);
224 	/* We can't reach the max gain with integration time smaller than MAX */
225 	KUNIT_EXPECT_NE(test, 0, ret);
226 
227 	ret = iio_gts_find_gain_sel_for_scale_using_time(&gts, TEST_TSEL_50, 0,
228 						TEST_SCALE_NANO_MAX_X, &gain_sel);
229 	/* We can't reach the max gain with integration time smaller than MAX */
230 	KUNIT_EXPECT_NE(test, 0, ret);
231 }
232 
233 static void test_iio_gts_find_new_gain_sel_by_old_gain_time(struct kunit *test)
234 {
235 	struct device *dev;
236 	int ret, old_gain, new_gain, old_time_sel, new_time_sel;
237 
238 	dev = test_init_iio_gain_scale(test, &gts);
239 	if (!dev)
240 		return;
241 
242 	old_gain = 32;
243 	old_time_sel = TEST_TSEL_200;
244 	new_time_sel = TEST_TSEL_400;
245 
246 	ret = iio_gts_find_new_gain_sel_by_old_gain_time(&gts, old_gain,
247 					old_time_sel, new_time_sel, &new_gain);
248 	KUNIT_EXPECT_EQ(test, 0, ret);
249 	/*
250 	 * Doubling the integration time doubles the total gain - so old
251 	 * (hw)gain must be divided by two to compensate. => 32 / 2 => 16
252 	 */
253 	KUNIT_EXPECT_EQ(test, 16, new_gain);
254 
255 	old_gain = 4;
256 	old_time_sel = TEST_TSEL_50;
257 	new_time_sel = TEST_TSEL_200;
258 	ret = iio_gts_find_new_gain_sel_by_old_gain_time(&gts, old_gain,
259 					old_time_sel, new_time_sel, &new_gain);
260 	KUNIT_EXPECT_EQ(test, 0, ret);
261 	/*
262 	 * gain by time 1x => 4x - (hw)gain 4x => 1x
263 	 */
264 	KUNIT_EXPECT_EQ(test, 1, new_gain);
265 
266 	old_gain = 512;
267 	old_time_sel = TEST_TSEL_400;
268 	new_time_sel = TEST_TSEL_50;
269 	ret = iio_gts_find_new_gain_sel_by_old_gain_time(&gts, old_gain,
270 					old_time_sel, new_time_sel, &new_gain);
271 	KUNIT_EXPECT_EQ(test, 0, ret);
272 	/*
273 	 * gain by time 8x => 1x - (hw)gain 512x => 4096x)
274 	 */
275 	KUNIT_EXPECT_EQ(test, 4096, new_gain);
276 
277 	/* Unsupported gain 2x */
278 	old_gain = 4;
279 	old_time_sel = TEST_TSEL_200;
280 	new_time_sel = TEST_TSEL_400;
281 	ret = iio_gts_find_new_gain_sel_by_old_gain_time(&gts, old_gain,
282 					old_time_sel, new_time_sel, &new_gain);
283 	KUNIT_EXPECT_NE(test, 0, ret);
284 
285 	/* Too small gain */
286 	old_gain = 4;
287 	old_time_sel = TEST_TSEL_50;
288 	new_time_sel = TEST_TSEL_400;
289 	ret = iio_gts_find_new_gain_sel_by_old_gain_time(&gts, old_gain,
290 					old_time_sel, new_time_sel, &new_gain);
291 	KUNIT_EXPECT_NE(test, 0, ret);
292 
293 	/* Too big gain */
294 	old_gain = 1024;
295 	old_time_sel = TEST_TSEL_400;
296 	new_time_sel = TEST_TSEL_50;
297 	ret = iio_gts_find_new_gain_sel_by_old_gain_time(&gts, old_gain,
298 					old_time_sel, new_time_sel, &new_gain);
299 	KUNIT_EXPECT_NE(test, 0, ret);
300 
301 }
302 
303 static void test_iio_find_closest_gain_low(struct kunit *test)
304 {
305 	struct device *dev;
306 	bool in_range;
307 	int ret;
308 
309 	const struct iio_gain_sel_pair gts_test_gains_gain_low[] = {
310 		GAIN_SCALE_GAIN(4, TEST_GSEL_4),
311 		GAIN_SCALE_GAIN(16, TEST_GSEL_16),
312 		GAIN_SCALE_GAIN(32, TEST_GSEL_32),
313 	};
314 
315 	dev = test_init_iio_gain_scale(test, &gts);
316 	if (!dev)
317 		return;
318 
319 	ret = iio_find_closest_gain_low(&gts, 2, &in_range);
320 	KUNIT_EXPECT_EQ(test, 1, ret);
321 	KUNIT_EXPECT_EQ(test, true, in_range);
322 
323 	ret = iio_find_closest_gain_low(&gts, 1, &in_range);
324 	KUNIT_EXPECT_EQ(test, 1, ret);
325 	KUNIT_EXPECT_EQ(test, true, in_range);
326 
327 	ret = iio_find_closest_gain_low(&gts, 4095, &in_range);
328 	KUNIT_EXPECT_EQ(test, 2048, ret);
329 	KUNIT_EXPECT_EQ(test, true, in_range);
330 
331 	ret = iio_find_closest_gain_low(&gts, 4097, &in_range);
332 	KUNIT_EXPECT_EQ(test, 4096, ret);
333 	KUNIT_EXPECT_EQ(test, false, in_range);
334 
335 	kunit_device_unregister(test, dev);
336 
337 	dev = __test_init_iio_gain_scale(test, &gts, gts_test_gains_gain_low,
338 				ARRAY_SIZE(gts_test_gains_gain_low),
339 				gts_test_itimes, ARRAY_SIZE(gts_test_itimes));
340 	if (!dev)
341 		return;
342 
343 	ret = iio_find_closest_gain_low(&gts, 3, &in_range);
344 	KUNIT_EXPECT_EQ(test, -EINVAL, ret);
345 	KUNIT_EXPECT_EQ(test, false, in_range);
346 }
347 
348 static void test_iio_gts_total_gain_to_scale(struct kunit *test)
349 {
350 	struct device *dev;
351 	int ret, scale_int, scale_nano;
352 
353 	dev = test_init_iio_gain_scale(test, &gts);
354 	if (!dev)
355 		return;
356 
357 	ret = iio_gts_total_gain_to_scale(&gts, 1, &scale_int, &scale_nano);
358 	KUNIT_EXPECT_EQ(test, 0, ret);
359 	KUNIT_EXPECT_EQ(test, TEST_SCALE_1X, scale_int);
360 	KUNIT_EXPECT_EQ(test, 0, scale_nano);
361 
362 	ret = iio_gts_total_gain_to_scale(&gts, 1, &scale_int, &scale_nano);
363 	KUNIT_EXPECT_EQ(test, 0, ret);
364 	KUNIT_EXPECT_EQ(test, TEST_SCALE_1X, scale_int);
365 	KUNIT_EXPECT_EQ(test, 0, scale_nano);
366 
367 	ret = iio_gts_total_gain_to_scale(&gts, 4096 * 8, &scale_int,
368 					  &scale_nano);
369 	KUNIT_EXPECT_EQ(test, 0, ret);
370 	KUNIT_EXPECT_EQ(test, 0, scale_int);
371 	KUNIT_EXPECT_EQ(test, TEST_SCALE_NANO_4096X8, scale_nano);
372 }
373 
374 static void test_iio_gts_chk_times(struct kunit *test, const int *vals)
375 {
376 	static const int expected[] = {0, 50000, 0, 100000, 0, 200000, 0, 400000};
377 	int i;
378 
379 	for (i = 0; i < ARRAY_SIZE(expected); i++)
380 		KUNIT_EXPECT_EQ(test, expected[i], vals[i]);
381 }
382 
383 static void test_iio_gts_chk_scales_all(struct kunit *test, struct iio_gts *gts,
384 					const int *vals, int len)
385 {
386 	static const int gains[] = {1, 2, 4, 8, 16, 32, 64, 128, 256, 512,
387 				    1024, 2048, 4096, 4096 * 2, 4096 * 4,
388 				    4096 * 8};
389 	int expected[ARRAY_SIZE(gains) * 2];
390 	int i, ret;
391 	int exp_len = ARRAY_SIZE(gains) * 2;
392 
393 	KUNIT_EXPECT_EQ(test, exp_len, len);
394 	if (len != exp_len)
395 		return;
396 
397 	for (i = 0; i < ARRAY_SIZE(gains); i++) {
398 		ret = iio_gts_total_gain_to_scale(gts, gains[i],
399 						  &expected[2 * i],
400 						  &expected[2 * i + 1]);
401 		KUNIT_EXPECT_EQ(test, 0, ret);
402 		if (ret)
403 			return;
404 	}
405 
406 	for (i = 0; i < ARRAY_SIZE(expected); i++)
407 		KUNIT_EXPECT_EQ(test, expected[i], vals[i]);
408 }
409 
410 static void test_iio_gts_chk_scales_t200(struct kunit *test, struct iio_gts *gts,
411 					 const int *vals, int len)
412 {
413 	/* The gain caused by time 200 is 4x */
414 	static const int gains[] = {
415 		1 * 4,
416 		4 * 4,
417 		16 * 4,
418 		32 * 4,
419 		64 * 4,
420 		256 * 4,
421 		512 * 4,
422 		1024 * 4,
423 		2048 * 4,
424 		4096 * 4
425 	};
426 	int expected[ARRAY_SIZE(gains) * 2];
427 	int i, ret;
428 
429 	KUNIT_EXPECT_EQ(test, 2 * ARRAY_SIZE(gains), len);
430 	if (len < 2 * ARRAY_SIZE(gains))
431 		return;
432 
433 	for (i = 0; i < ARRAY_SIZE(gains); i++) {
434 		ret = iio_gts_total_gain_to_scale(gts, gains[i],
435 						  &expected[2 * i],
436 						  &expected[2 * i + 1]);
437 		KUNIT_EXPECT_EQ(test, 0, ret);
438 		if (ret)
439 			return;
440 	}
441 
442 	for (i = 0; i < ARRAY_SIZE(expected); i++)
443 		KUNIT_EXPECT_EQ(test, expected[i], vals[i]);
444 }
445 
446 static void test_iio_gts_avail_test(struct kunit *test)
447 {
448 	struct device *dev;
449 	int ret;
450 	int type, len;
451 	const int *vals;
452 
453 	dev = test_init_iio_gain_scale(test, &gts);
454 	if (!dev)
455 		return;
456 
457 	/* test table building for times and iio_gts_avail_times() */
458 	ret = iio_gts_avail_times(&gts, &vals, &type, &len);
459 	KUNIT_EXPECT_EQ(test, IIO_AVAIL_LIST, ret);
460 	if (ret)
461 		return;
462 
463 	KUNIT_EXPECT_EQ(test, IIO_VAL_INT_PLUS_MICRO, type);
464 	KUNIT_EXPECT_EQ(test, 8, len);
465 	if (len < 8)
466 		return;
467 
468 	test_iio_gts_chk_times(test, vals);
469 
470 	/* Test table building for all scales and iio_gts_all_avail_scales() */
471 	ret = iio_gts_all_avail_scales(&gts, &vals, &type, &len);
472 	KUNIT_EXPECT_EQ(test, IIO_AVAIL_LIST, ret);
473 	if (ret)
474 		return;
475 
476 	KUNIT_EXPECT_EQ(test, IIO_VAL_INT_PLUS_NANO, type);
477 
478 	test_iio_gts_chk_scales_all(test, &gts, vals, len);
479 
480 	/*
481 	 * Test table building for scales/time and
482 	 * iio_gts_avail_scales_for_time()
483 	 */
484 	ret = iio_gts_avail_scales_for_time(&gts, 200000, &vals, &type, &len);
485 	KUNIT_EXPECT_EQ(test, IIO_AVAIL_LIST, ret);
486 	if (ret)
487 		return;
488 
489 	KUNIT_EXPECT_EQ(test, IIO_VAL_INT_PLUS_NANO, type);
490 	test_iio_gts_chk_scales_t200(test, &gts, vals, len);
491 }
492 
493 static struct kunit_case iio_gts_test_cases[] = {
494 	KUNIT_CASE(test_init_iio_gts_invalid),
495 	KUNIT_CASE(test_iio_gts_find_gain_for_scale_using_time),
496 	KUNIT_CASE(test_iio_gts_find_new_gain_sel_by_old_gain_time),
497 	KUNIT_CASE(test_iio_find_closest_gain_low),
498 	KUNIT_CASE(test_iio_gts_total_gain_to_scale),
499 	KUNIT_CASE(test_iio_gts_avail_test),
500 	{}
501 };
502 
503 static struct kunit_suite iio_gts_test_suite = {
504 	.name = "iio-gain-time-scale",
505 	.test_cases = iio_gts_test_cases,
506 };
507 
508 kunit_test_suite(iio_gts_test_suite);
509 
510 MODULE_LICENSE("GPL");
511 MODULE_AUTHOR("Matti Vaittinen <mazziesaccount@gmail.com>");
512 MODULE_DESCRIPTION("Test IIO light sensor gain-time-scale helpers");
513 MODULE_IMPORT_NS(IIO_GTS_HELPER);
514