1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * STM32 Low-Power Timer Encoder and Counter driver
4 *
5 * Copyright (C) STMicroelectronics 2017
6 *
7 * Author: Fabrice Gasnier <fabrice.gasnier@st.com>
8 *
9 * Inspired by 104-quad-8 and stm32-timer-trigger drivers.
10 *
11 */
12
13 #include <linux/bitfield.h>
14 #include <linux/counter.h>
15 #include <linux/iio/iio.h>
16 #include <linux/mfd/stm32-lptimer.h>
17 #include <linux/module.h>
18 #include <linux/pinctrl/consumer.h>
19 #include <linux/platform_device.h>
20
21 struct stm32_lptim_cnt {
22 struct counter_device counter;
23 struct device *dev;
24 struct regmap *regmap;
25 struct clk *clk;
26 u32 ceiling;
27 u32 polarity;
28 u32 quadrature_mode;
29 bool enabled;
30 };
31
stm32_lptim_is_enabled(struct stm32_lptim_cnt * priv)32 static int stm32_lptim_is_enabled(struct stm32_lptim_cnt *priv)
33 {
34 u32 val;
35 int ret;
36
37 ret = regmap_read(priv->regmap, STM32_LPTIM_CR, &val);
38 if (ret)
39 return ret;
40
41 return FIELD_GET(STM32_LPTIM_ENABLE, val);
42 }
43
stm32_lptim_set_enable_state(struct stm32_lptim_cnt * priv,int enable)44 static int stm32_lptim_set_enable_state(struct stm32_lptim_cnt *priv,
45 int enable)
46 {
47 int ret;
48 u32 val;
49
50 val = FIELD_PREP(STM32_LPTIM_ENABLE, enable);
51 ret = regmap_write(priv->regmap, STM32_LPTIM_CR, val);
52 if (ret)
53 return ret;
54
55 if (!enable) {
56 clk_disable(priv->clk);
57 priv->enabled = false;
58 return 0;
59 }
60
61 /* LP timer must be enabled before writing CMP & ARR */
62 ret = regmap_write(priv->regmap, STM32_LPTIM_ARR, priv->ceiling);
63 if (ret)
64 return ret;
65
66 ret = regmap_write(priv->regmap, STM32_LPTIM_CMP, 0);
67 if (ret)
68 return ret;
69
70 /* ensure CMP & ARR registers are properly written */
71 ret = regmap_read_poll_timeout(priv->regmap, STM32_LPTIM_ISR, val,
72 (val & STM32_LPTIM_CMPOK_ARROK),
73 100, 1000);
74 if (ret)
75 return ret;
76
77 ret = regmap_write(priv->regmap, STM32_LPTIM_ICR,
78 STM32_LPTIM_CMPOKCF_ARROKCF);
79 if (ret)
80 return ret;
81
82 ret = clk_enable(priv->clk);
83 if (ret) {
84 regmap_write(priv->regmap, STM32_LPTIM_CR, 0);
85 return ret;
86 }
87 priv->enabled = true;
88
89 /* Start LP timer in continuous mode */
90 return regmap_update_bits(priv->regmap, STM32_LPTIM_CR,
91 STM32_LPTIM_CNTSTRT, STM32_LPTIM_CNTSTRT);
92 }
93
stm32_lptim_setup(struct stm32_lptim_cnt * priv,int enable)94 static int stm32_lptim_setup(struct stm32_lptim_cnt *priv, int enable)
95 {
96 u32 mask = STM32_LPTIM_ENC | STM32_LPTIM_COUNTMODE |
97 STM32_LPTIM_CKPOL | STM32_LPTIM_PRESC;
98 u32 val;
99
100 /* Setup LP timer encoder/counter and polarity, without prescaler */
101 if (priv->quadrature_mode)
102 val = enable ? STM32_LPTIM_ENC : 0;
103 else
104 val = enable ? STM32_LPTIM_COUNTMODE : 0;
105 val |= FIELD_PREP(STM32_LPTIM_CKPOL, enable ? priv->polarity : 0);
106
107 return regmap_update_bits(priv->regmap, STM32_LPTIM_CFGR, mask, val);
108 }
109
stm32_lptim_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)110 static int stm32_lptim_write_raw(struct iio_dev *indio_dev,
111 struct iio_chan_spec const *chan,
112 int val, int val2, long mask)
113 {
114 struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
115 int ret;
116
117 switch (mask) {
118 case IIO_CHAN_INFO_ENABLE:
119 if (val < 0 || val > 1)
120 return -EINVAL;
121
122 /* Check nobody uses the timer, or already disabled/enabled */
123 ret = stm32_lptim_is_enabled(priv);
124 if ((ret < 0) || (!ret && !val))
125 return ret;
126 if (val && ret)
127 return -EBUSY;
128
129 ret = stm32_lptim_setup(priv, val);
130 if (ret)
131 return ret;
132 return stm32_lptim_set_enable_state(priv, val);
133
134 default:
135 return -EINVAL;
136 }
137 }
138
stm32_lptim_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)139 static int stm32_lptim_read_raw(struct iio_dev *indio_dev,
140 struct iio_chan_spec const *chan,
141 int *val, int *val2, long mask)
142 {
143 struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
144 u32 dat;
145 int ret;
146
147 switch (mask) {
148 case IIO_CHAN_INFO_RAW:
149 ret = regmap_read(priv->regmap, STM32_LPTIM_CNT, &dat);
150 if (ret)
151 return ret;
152 *val = dat;
153 return IIO_VAL_INT;
154
155 case IIO_CHAN_INFO_ENABLE:
156 ret = stm32_lptim_is_enabled(priv);
157 if (ret < 0)
158 return ret;
159 *val = ret;
160 return IIO_VAL_INT;
161
162 case IIO_CHAN_INFO_SCALE:
163 /* Non-quadrature mode: scale = 1 */
164 *val = 1;
165 *val2 = 0;
166 if (priv->quadrature_mode) {
167 /*
168 * Quadrature encoder mode:
169 * - both edges, quarter cycle, scale is 0.25
170 * - either rising/falling edge scale is 0.5
171 */
172 if (priv->polarity > 1)
173 *val2 = 2;
174 else
175 *val2 = 1;
176 }
177 return IIO_VAL_FRACTIONAL_LOG2;
178
179 default:
180 return -EINVAL;
181 }
182 }
183
184 static const struct iio_info stm32_lptim_cnt_iio_info = {
185 .read_raw = stm32_lptim_read_raw,
186 .write_raw = stm32_lptim_write_raw,
187 };
188
189 static const char *const stm32_lptim_quadrature_modes[] = {
190 "non-quadrature",
191 "quadrature",
192 };
193
stm32_lptim_get_quadrature_mode(struct iio_dev * indio_dev,const struct iio_chan_spec * chan)194 static int stm32_lptim_get_quadrature_mode(struct iio_dev *indio_dev,
195 const struct iio_chan_spec *chan)
196 {
197 struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
198
199 return priv->quadrature_mode;
200 }
201
stm32_lptim_set_quadrature_mode(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,unsigned int type)202 static int stm32_lptim_set_quadrature_mode(struct iio_dev *indio_dev,
203 const struct iio_chan_spec *chan,
204 unsigned int type)
205 {
206 struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
207
208 if (stm32_lptim_is_enabled(priv))
209 return -EBUSY;
210
211 priv->quadrature_mode = type;
212
213 return 0;
214 }
215
216 static const struct iio_enum stm32_lptim_quadrature_mode_en = {
217 .items = stm32_lptim_quadrature_modes,
218 .num_items = ARRAY_SIZE(stm32_lptim_quadrature_modes),
219 .get = stm32_lptim_get_quadrature_mode,
220 .set = stm32_lptim_set_quadrature_mode,
221 };
222
223 static const char * const stm32_lptim_cnt_polarity[] = {
224 "rising-edge", "falling-edge", "both-edges",
225 };
226
stm32_lptim_cnt_get_polarity(struct iio_dev * indio_dev,const struct iio_chan_spec * chan)227 static int stm32_lptim_cnt_get_polarity(struct iio_dev *indio_dev,
228 const struct iio_chan_spec *chan)
229 {
230 struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
231
232 return priv->polarity;
233 }
234
stm32_lptim_cnt_set_polarity(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,unsigned int type)235 static int stm32_lptim_cnt_set_polarity(struct iio_dev *indio_dev,
236 const struct iio_chan_spec *chan,
237 unsigned int type)
238 {
239 struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
240
241 if (stm32_lptim_is_enabled(priv))
242 return -EBUSY;
243
244 priv->polarity = type;
245
246 return 0;
247 }
248
249 static const struct iio_enum stm32_lptim_cnt_polarity_en = {
250 .items = stm32_lptim_cnt_polarity,
251 .num_items = ARRAY_SIZE(stm32_lptim_cnt_polarity),
252 .get = stm32_lptim_cnt_get_polarity,
253 .set = stm32_lptim_cnt_set_polarity,
254 };
255
stm32_lptim_cnt_get_ceiling(struct stm32_lptim_cnt * priv,char * buf)256 static ssize_t stm32_lptim_cnt_get_ceiling(struct stm32_lptim_cnt *priv,
257 char *buf)
258 {
259 return snprintf(buf, PAGE_SIZE, "%u\n", priv->ceiling);
260 }
261
stm32_lptim_cnt_set_ceiling(struct stm32_lptim_cnt * priv,const char * buf,size_t len)262 static ssize_t stm32_lptim_cnt_set_ceiling(struct stm32_lptim_cnt *priv,
263 const char *buf, size_t len)
264 {
265 int ret;
266
267 if (stm32_lptim_is_enabled(priv))
268 return -EBUSY;
269
270 ret = kstrtouint(buf, 0, &priv->ceiling);
271 if (ret)
272 return ret;
273
274 if (priv->ceiling > STM32_LPTIM_MAX_ARR)
275 return -EINVAL;
276
277 return len;
278 }
279
stm32_lptim_cnt_get_preset_iio(struct iio_dev * indio_dev,uintptr_t private,const struct iio_chan_spec * chan,char * buf)280 static ssize_t stm32_lptim_cnt_get_preset_iio(struct iio_dev *indio_dev,
281 uintptr_t private,
282 const struct iio_chan_spec *chan,
283 char *buf)
284 {
285 struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
286
287 return stm32_lptim_cnt_get_ceiling(priv, buf);
288 }
289
stm32_lptim_cnt_set_preset_iio(struct iio_dev * indio_dev,uintptr_t private,const struct iio_chan_spec * chan,const char * buf,size_t len)290 static ssize_t stm32_lptim_cnt_set_preset_iio(struct iio_dev *indio_dev,
291 uintptr_t private,
292 const struct iio_chan_spec *chan,
293 const char *buf, size_t len)
294 {
295 struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
296
297 return stm32_lptim_cnt_set_ceiling(priv, buf, len);
298 }
299
300 /* LP timer with encoder */
301 static const struct iio_chan_spec_ext_info stm32_lptim_enc_ext_info[] = {
302 {
303 .name = "preset",
304 .shared = IIO_SEPARATE,
305 .read = stm32_lptim_cnt_get_preset_iio,
306 .write = stm32_lptim_cnt_set_preset_iio,
307 },
308 IIO_ENUM("polarity", IIO_SEPARATE, &stm32_lptim_cnt_polarity_en),
309 IIO_ENUM_AVAILABLE("polarity", &stm32_lptim_cnt_polarity_en),
310 IIO_ENUM("quadrature_mode", IIO_SEPARATE,
311 &stm32_lptim_quadrature_mode_en),
312 IIO_ENUM_AVAILABLE("quadrature_mode", &stm32_lptim_quadrature_mode_en),
313 {}
314 };
315
316 static const struct iio_chan_spec stm32_lptim_enc_channels = {
317 .type = IIO_COUNT,
318 .channel = 0,
319 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
320 BIT(IIO_CHAN_INFO_ENABLE) |
321 BIT(IIO_CHAN_INFO_SCALE),
322 .ext_info = stm32_lptim_enc_ext_info,
323 .indexed = 1,
324 };
325
326 /* LP timer without encoder (counter only) */
327 static const struct iio_chan_spec_ext_info stm32_lptim_cnt_ext_info[] = {
328 {
329 .name = "preset",
330 .shared = IIO_SEPARATE,
331 .read = stm32_lptim_cnt_get_preset_iio,
332 .write = stm32_lptim_cnt_set_preset_iio,
333 },
334 IIO_ENUM("polarity", IIO_SEPARATE, &stm32_lptim_cnt_polarity_en),
335 IIO_ENUM_AVAILABLE("polarity", &stm32_lptim_cnt_polarity_en),
336 {}
337 };
338
339 static const struct iio_chan_spec stm32_lptim_cnt_channels = {
340 .type = IIO_COUNT,
341 .channel = 0,
342 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
343 BIT(IIO_CHAN_INFO_ENABLE) |
344 BIT(IIO_CHAN_INFO_SCALE),
345 .ext_info = stm32_lptim_cnt_ext_info,
346 .indexed = 1,
347 };
348
349 /**
350 * stm32_lptim_cnt_function - enumerates stm32 LPTimer counter & encoder modes
351 * @STM32_LPTIM_COUNTER_INCREASE: up count on IN1 rising, falling or both edges
352 * @STM32_LPTIM_ENCODER_BOTH_EDGE: count on both edges (IN1 & IN2 quadrature)
353 */
354 enum stm32_lptim_cnt_function {
355 STM32_LPTIM_COUNTER_INCREASE,
356 STM32_LPTIM_ENCODER_BOTH_EDGE,
357 };
358
359 static enum counter_count_function stm32_lptim_cnt_functions[] = {
360 [STM32_LPTIM_COUNTER_INCREASE] = COUNTER_COUNT_FUNCTION_INCREASE,
361 [STM32_LPTIM_ENCODER_BOTH_EDGE] = COUNTER_COUNT_FUNCTION_QUADRATURE_X4,
362 };
363
364 enum stm32_lptim_synapse_action {
365 STM32_LPTIM_SYNAPSE_ACTION_RISING_EDGE,
366 STM32_LPTIM_SYNAPSE_ACTION_FALLING_EDGE,
367 STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES,
368 STM32_LPTIM_SYNAPSE_ACTION_NONE,
369 };
370
371 static enum counter_synapse_action stm32_lptim_cnt_synapse_actions[] = {
372 /* Index must match with stm32_lptim_cnt_polarity[] (priv->polarity) */
373 [STM32_LPTIM_SYNAPSE_ACTION_RISING_EDGE] = COUNTER_SYNAPSE_ACTION_RISING_EDGE,
374 [STM32_LPTIM_SYNAPSE_ACTION_FALLING_EDGE] = COUNTER_SYNAPSE_ACTION_FALLING_EDGE,
375 [STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES] = COUNTER_SYNAPSE_ACTION_BOTH_EDGES,
376 [STM32_LPTIM_SYNAPSE_ACTION_NONE] = COUNTER_SYNAPSE_ACTION_NONE,
377 };
378
stm32_lptim_cnt_read(struct counter_device * counter,struct counter_count * count,struct counter_count_read_value * val)379 static int stm32_lptim_cnt_read(struct counter_device *counter,
380 struct counter_count *count,
381 struct counter_count_read_value *val)
382 {
383 struct stm32_lptim_cnt *const priv = counter->priv;
384 u32 cnt;
385 int ret;
386
387 ret = regmap_read(priv->regmap, STM32_LPTIM_CNT, &cnt);
388 if (ret)
389 return ret;
390
391 counter_count_read_value_set(val, COUNTER_COUNT_POSITION, &cnt);
392
393 return 0;
394 }
395
stm32_lptim_cnt_function_get(struct counter_device * counter,struct counter_count * count,size_t * function)396 static int stm32_lptim_cnt_function_get(struct counter_device *counter,
397 struct counter_count *count,
398 size_t *function)
399 {
400 struct stm32_lptim_cnt *const priv = counter->priv;
401
402 if (!priv->quadrature_mode) {
403 *function = STM32_LPTIM_COUNTER_INCREASE;
404 return 0;
405 }
406
407 if (priv->polarity == STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES) {
408 *function = STM32_LPTIM_ENCODER_BOTH_EDGE;
409 return 0;
410 }
411
412 return -EINVAL;
413 }
414
stm32_lptim_cnt_function_set(struct counter_device * counter,struct counter_count * count,size_t function)415 static int stm32_lptim_cnt_function_set(struct counter_device *counter,
416 struct counter_count *count,
417 size_t function)
418 {
419 struct stm32_lptim_cnt *const priv = counter->priv;
420
421 if (stm32_lptim_is_enabled(priv))
422 return -EBUSY;
423
424 switch (function) {
425 case STM32_LPTIM_COUNTER_INCREASE:
426 priv->quadrature_mode = 0;
427 return 0;
428 case STM32_LPTIM_ENCODER_BOTH_EDGE:
429 priv->quadrature_mode = 1;
430 priv->polarity = STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES;
431 return 0;
432 }
433
434 return -EINVAL;
435 }
436
stm32_lptim_cnt_enable_read(struct counter_device * counter,struct counter_count * count,void * private,char * buf)437 static ssize_t stm32_lptim_cnt_enable_read(struct counter_device *counter,
438 struct counter_count *count,
439 void *private, char *buf)
440 {
441 struct stm32_lptim_cnt *const priv = counter->priv;
442 int ret;
443
444 ret = stm32_lptim_is_enabled(priv);
445 if (ret < 0)
446 return ret;
447
448 return scnprintf(buf, PAGE_SIZE, "%u\n", ret);
449 }
450
stm32_lptim_cnt_enable_write(struct counter_device * counter,struct counter_count * count,void * private,const char * buf,size_t len)451 static ssize_t stm32_lptim_cnt_enable_write(struct counter_device *counter,
452 struct counter_count *count,
453 void *private,
454 const char *buf, size_t len)
455 {
456 struct stm32_lptim_cnt *const priv = counter->priv;
457 bool enable;
458 int ret;
459
460 ret = kstrtobool(buf, &enable);
461 if (ret)
462 return ret;
463
464 /* Check nobody uses the timer, or already disabled/enabled */
465 ret = stm32_lptim_is_enabled(priv);
466 if ((ret < 0) || (!ret && !enable))
467 return ret;
468 if (enable && ret)
469 return -EBUSY;
470
471 ret = stm32_lptim_setup(priv, enable);
472 if (ret)
473 return ret;
474
475 ret = stm32_lptim_set_enable_state(priv, enable);
476 if (ret)
477 return ret;
478
479 return len;
480 }
481
stm32_lptim_cnt_ceiling_read(struct counter_device * counter,struct counter_count * count,void * private,char * buf)482 static ssize_t stm32_lptim_cnt_ceiling_read(struct counter_device *counter,
483 struct counter_count *count,
484 void *private, char *buf)
485 {
486 struct stm32_lptim_cnt *const priv = counter->priv;
487
488 return stm32_lptim_cnt_get_ceiling(priv, buf);
489 }
490
stm32_lptim_cnt_ceiling_write(struct counter_device * counter,struct counter_count * count,void * private,const char * buf,size_t len)491 static ssize_t stm32_lptim_cnt_ceiling_write(struct counter_device *counter,
492 struct counter_count *count,
493 void *private,
494 const char *buf, size_t len)
495 {
496 struct stm32_lptim_cnt *const priv = counter->priv;
497
498 return stm32_lptim_cnt_set_ceiling(priv, buf, len);
499 }
500
501 static const struct counter_count_ext stm32_lptim_cnt_ext[] = {
502 {
503 .name = "enable",
504 .read = stm32_lptim_cnt_enable_read,
505 .write = stm32_lptim_cnt_enable_write
506 },
507 {
508 .name = "ceiling",
509 .read = stm32_lptim_cnt_ceiling_read,
510 .write = stm32_lptim_cnt_ceiling_write
511 },
512 };
513
stm32_lptim_cnt_action_get(struct counter_device * counter,struct counter_count * count,struct counter_synapse * synapse,size_t * action)514 static int stm32_lptim_cnt_action_get(struct counter_device *counter,
515 struct counter_count *count,
516 struct counter_synapse *synapse,
517 size_t *action)
518 {
519 struct stm32_lptim_cnt *const priv = counter->priv;
520 size_t function;
521 int err;
522
523 err = stm32_lptim_cnt_function_get(counter, count, &function);
524 if (err)
525 return err;
526
527 switch (function) {
528 case STM32_LPTIM_COUNTER_INCREASE:
529 /* LP Timer acts as up-counter on input 1 */
530 if (synapse->signal->id == count->synapses[0].signal->id)
531 *action = priv->polarity;
532 else
533 *action = STM32_LPTIM_SYNAPSE_ACTION_NONE;
534 return 0;
535 case STM32_LPTIM_ENCODER_BOTH_EDGE:
536 *action = priv->polarity;
537 return 0;
538 }
539
540 return -EINVAL;
541 }
542
stm32_lptim_cnt_action_set(struct counter_device * counter,struct counter_count * count,struct counter_synapse * synapse,size_t action)543 static int stm32_lptim_cnt_action_set(struct counter_device *counter,
544 struct counter_count *count,
545 struct counter_synapse *synapse,
546 size_t action)
547 {
548 struct stm32_lptim_cnt *const priv = counter->priv;
549 size_t function;
550 int err;
551
552 if (stm32_lptim_is_enabled(priv))
553 return -EBUSY;
554
555 err = stm32_lptim_cnt_function_get(counter, count, &function);
556 if (err)
557 return err;
558
559 /* only set polarity when in counter mode (on input 1) */
560 if (function == STM32_LPTIM_COUNTER_INCREASE
561 && synapse->signal->id == count->synapses[0].signal->id) {
562 switch (action) {
563 case STM32_LPTIM_SYNAPSE_ACTION_RISING_EDGE:
564 case STM32_LPTIM_SYNAPSE_ACTION_FALLING_EDGE:
565 case STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES:
566 priv->polarity = action;
567 return 0;
568 }
569 }
570
571 return -EINVAL;
572 }
573
574 static const struct counter_ops stm32_lptim_cnt_ops = {
575 .count_read = stm32_lptim_cnt_read,
576 .function_get = stm32_lptim_cnt_function_get,
577 .function_set = stm32_lptim_cnt_function_set,
578 .action_get = stm32_lptim_cnt_action_get,
579 .action_set = stm32_lptim_cnt_action_set,
580 };
581
582 static struct counter_signal stm32_lptim_cnt_signals[] = {
583 {
584 .id = 0,
585 .name = "Channel 1 Quadrature A"
586 },
587 {
588 .id = 1,
589 .name = "Channel 1 Quadrature B"
590 }
591 };
592
593 static struct counter_synapse stm32_lptim_cnt_synapses[] = {
594 {
595 .actions_list = stm32_lptim_cnt_synapse_actions,
596 .num_actions = ARRAY_SIZE(stm32_lptim_cnt_synapse_actions),
597 .signal = &stm32_lptim_cnt_signals[0]
598 },
599 {
600 .actions_list = stm32_lptim_cnt_synapse_actions,
601 .num_actions = ARRAY_SIZE(stm32_lptim_cnt_synapse_actions),
602 .signal = &stm32_lptim_cnt_signals[1]
603 }
604 };
605
606 /* LP timer with encoder */
607 static struct counter_count stm32_lptim_enc_counts = {
608 .id = 0,
609 .name = "LPTimer Count",
610 .functions_list = stm32_lptim_cnt_functions,
611 .num_functions = ARRAY_SIZE(stm32_lptim_cnt_functions),
612 .synapses = stm32_lptim_cnt_synapses,
613 .num_synapses = ARRAY_SIZE(stm32_lptim_cnt_synapses),
614 .ext = stm32_lptim_cnt_ext,
615 .num_ext = ARRAY_SIZE(stm32_lptim_cnt_ext)
616 };
617
618 /* LP timer without encoder (counter only) */
619 static struct counter_count stm32_lptim_in1_counts = {
620 .id = 0,
621 .name = "LPTimer Count",
622 .functions_list = stm32_lptim_cnt_functions,
623 .num_functions = 1,
624 .synapses = stm32_lptim_cnt_synapses,
625 .num_synapses = 1,
626 .ext = stm32_lptim_cnt_ext,
627 .num_ext = ARRAY_SIZE(stm32_lptim_cnt_ext)
628 };
629
stm32_lptim_cnt_probe(struct platform_device * pdev)630 static int stm32_lptim_cnt_probe(struct platform_device *pdev)
631 {
632 struct stm32_lptimer *ddata = dev_get_drvdata(pdev->dev.parent);
633 struct stm32_lptim_cnt *priv;
634 struct iio_dev *indio_dev;
635 int ret;
636
637 if (IS_ERR_OR_NULL(ddata))
638 return -EINVAL;
639
640 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv));
641 if (!indio_dev)
642 return -ENOMEM;
643
644 priv = iio_priv(indio_dev);
645 priv->dev = &pdev->dev;
646 priv->regmap = ddata->regmap;
647 priv->clk = ddata->clk;
648 priv->ceiling = STM32_LPTIM_MAX_ARR;
649
650 /* Initialize IIO device */
651 indio_dev->name = dev_name(&pdev->dev);
652 indio_dev->dev.parent = &pdev->dev;
653 indio_dev->dev.of_node = pdev->dev.of_node;
654 indio_dev->info = &stm32_lptim_cnt_iio_info;
655 if (ddata->has_encoder)
656 indio_dev->channels = &stm32_lptim_enc_channels;
657 else
658 indio_dev->channels = &stm32_lptim_cnt_channels;
659 indio_dev->num_channels = 1;
660
661 /* Initialize Counter device */
662 priv->counter.name = dev_name(&pdev->dev);
663 priv->counter.parent = &pdev->dev;
664 priv->counter.ops = &stm32_lptim_cnt_ops;
665 if (ddata->has_encoder) {
666 priv->counter.counts = &stm32_lptim_enc_counts;
667 priv->counter.num_signals = ARRAY_SIZE(stm32_lptim_cnt_signals);
668 } else {
669 priv->counter.counts = &stm32_lptim_in1_counts;
670 priv->counter.num_signals = 1;
671 }
672 priv->counter.num_counts = 1;
673 priv->counter.signals = stm32_lptim_cnt_signals;
674 priv->counter.priv = priv;
675
676 platform_set_drvdata(pdev, priv);
677
678 ret = devm_iio_device_register(&pdev->dev, indio_dev);
679 if (ret)
680 return ret;
681
682 return devm_counter_register(&pdev->dev, &priv->counter);
683 }
684
685 #ifdef CONFIG_PM_SLEEP
stm32_lptim_cnt_suspend(struct device * dev)686 static int stm32_lptim_cnt_suspend(struct device *dev)
687 {
688 struct stm32_lptim_cnt *priv = dev_get_drvdata(dev);
689 int ret;
690
691 /* Only take care of enabled counter: don't disturb other MFD child */
692 if (priv->enabled) {
693 ret = stm32_lptim_setup(priv, 0);
694 if (ret)
695 return ret;
696
697 ret = stm32_lptim_set_enable_state(priv, 0);
698 if (ret)
699 return ret;
700
701 /* Force enable state for later resume */
702 priv->enabled = true;
703 }
704
705 return pinctrl_pm_select_sleep_state(dev);
706 }
707
stm32_lptim_cnt_resume(struct device * dev)708 static int stm32_lptim_cnt_resume(struct device *dev)
709 {
710 struct stm32_lptim_cnt *priv = dev_get_drvdata(dev);
711 int ret;
712
713 ret = pinctrl_pm_select_default_state(dev);
714 if (ret)
715 return ret;
716
717 if (priv->enabled) {
718 priv->enabled = false;
719 ret = stm32_lptim_setup(priv, 1);
720 if (ret)
721 return ret;
722
723 ret = stm32_lptim_set_enable_state(priv, 1);
724 if (ret)
725 return ret;
726 }
727
728 return 0;
729 }
730 #endif
731
732 static SIMPLE_DEV_PM_OPS(stm32_lptim_cnt_pm_ops, stm32_lptim_cnt_suspend,
733 stm32_lptim_cnt_resume);
734
735 static const struct of_device_id stm32_lptim_cnt_of_match[] = {
736 { .compatible = "st,stm32-lptimer-counter", },
737 {},
738 };
739 MODULE_DEVICE_TABLE(of, stm32_lptim_cnt_of_match);
740
741 static struct platform_driver stm32_lptim_cnt_driver = {
742 .probe = stm32_lptim_cnt_probe,
743 .driver = {
744 .name = "stm32-lptimer-counter",
745 .of_match_table = stm32_lptim_cnt_of_match,
746 .pm = &stm32_lptim_cnt_pm_ops,
747 },
748 };
749 module_platform_driver(stm32_lptim_cnt_driver);
750
751 MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
752 MODULE_ALIAS("platform:stm32-lptimer-counter");
753 MODULE_DESCRIPTION("STMicroelectronics STM32 LPTIM counter driver");
754 MODULE_LICENSE("GPL v2");
755
