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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/mfd/stm32-lptimer.h>
16#include <linux/mod_devicetable.h>
17#include <linux/module.h>
18#include <linux/pinctrl/consumer.h>
19#include <linux/platform_device.h>
20#include <linux/types.h>
21
22struct stm32_lptim_cnt {
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
32static 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
44static 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) == 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
94static 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
110/*
111 * In non-quadrature mode, device counts up on active edge.
112 * In quadrature mode, encoder counting scenarios are as follows:
113 * +---------+----------+--------------------+--------------------+
114 * | Active | Level on | IN1 signal | IN2 signal |
115 * | edge | opposite +----------+---------+----------+---------+
116 * | | signal | Rising | Falling | Rising | Falling |
117 * +---------+----------+----------+---------+----------+---------+
118 * | Rising | High -> | Down | - | Up | - |
119 * | edge | Low -> | Up | - | Down | - |
120 * +---------+----------+----------+---------+----------+---------+
121 * | Falling | High -> | - | Up | - | Down |
122 * | edge | Low -> | - | Down | - | Up |
123 * +---------+----------+----------+---------+----------+---------+
124 * | Both | High -> | Down | Up | Up | Down |
125 * | edges | Low -> | Up | Down | Down | Up |
126 * +---------+----------+----------+---------+----------+---------+
127 */
128static const enum counter_function stm32_lptim_cnt_functions[] = {
129 COUNTER_FUNCTION_INCREASE,
130 COUNTER_FUNCTION_QUADRATURE_X4,
131};
132
133static const enum counter_synapse_action stm32_lptim_cnt_synapse_actions[] = {
134 COUNTER_SYNAPSE_ACTION_RISING_EDGE,
135 COUNTER_SYNAPSE_ACTION_FALLING_EDGE,
136 COUNTER_SYNAPSE_ACTION_BOTH_EDGES,
137 COUNTER_SYNAPSE_ACTION_NONE,
138};
139
140static int stm32_lptim_cnt_read(struct counter_device *counter,
141 struct counter_count *count, u64 *val)
142{
143 struct stm32_lptim_cnt *const priv = counter_priv(counter);
144 u32 cnt;
145 int ret;
146
147 ret = regmap_read(priv->regmap, STM32_LPTIM_CNT, &cnt);
148 if (ret)
149 return ret;
150
151 *val = cnt;
152
153 return 0;
154}
155
156static int stm32_lptim_cnt_function_read(struct counter_device *counter,
157 struct counter_count *count,
158 enum counter_function *function)
159{
160 struct stm32_lptim_cnt *const priv = counter_priv(counter);
161
162 if (!priv->quadrature_mode) {
163 *function = COUNTER_FUNCTION_INCREASE;
164 return 0;
165 }
166
167 if (priv->polarity == STM32_LPTIM_CKPOL_BOTH_EDGES) {
168 *function = COUNTER_FUNCTION_QUADRATURE_X4;
169 return 0;
170 }
171
172 return -EINVAL;
173}
174
175static int stm32_lptim_cnt_function_write(struct counter_device *counter,
176 struct counter_count *count,
177 enum counter_function function)
178{
179 struct stm32_lptim_cnt *const priv = counter_priv(counter);
180
181 if (stm32_lptim_is_enabled(priv))
182 return -EBUSY;
183
184 switch (function) {
185 case COUNTER_FUNCTION_INCREASE:
186 priv->quadrature_mode = 0;
187 return 0;
188 case COUNTER_FUNCTION_QUADRATURE_X4:
189 priv->quadrature_mode = 1;
190 priv->polarity = STM32_LPTIM_CKPOL_BOTH_EDGES;
191 return 0;
192 default:
193 /* should never reach this path */
194 return -EINVAL;
195 }
196}
197
198static int stm32_lptim_cnt_enable_read(struct counter_device *counter,
199 struct counter_count *count,
200 u8 *enable)
201{
202 struct stm32_lptim_cnt *const priv = counter_priv(counter);
203 int ret;
204
205 ret = stm32_lptim_is_enabled(priv);
206 if (ret < 0)
207 return ret;
208
209 *enable = ret;
210
211 return 0;
212}
213
214static int stm32_lptim_cnt_enable_write(struct counter_device *counter,
215 struct counter_count *count,
216 u8 enable)
217{
218 struct stm32_lptim_cnt *const priv = counter_priv(counter);
219 int ret;
220
221 /* Check nobody uses the timer, or already disabled/enabled */
222 ret = stm32_lptim_is_enabled(priv);
223 if ((ret < 0) || (!ret && !enable))
224 return ret;
225 if (enable && ret)
226 return -EBUSY;
227
228 ret = stm32_lptim_setup(priv, enable);
229 if (ret)
230 return ret;
231
232 ret = stm32_lptim_set_enable_state(priv, enable);
233 if (ret)
234 return ret;
235
236 return 0;
237}
238
239static int stm32_lptim_cnt_ceiling_read(struct counter_device *counter,
240 struct counter_count *count,
241 u64 *ceiling)
242{
243 struct stm32_lptim_cnt *const priv = counter_priv(counter);
244
245 *ceiling = priv->ceiling;
246
247 return 0;
248}
249
250static int stm32_lptim_cnt_ceiling_write(struct counter_device *counter,
251 struct counter_count *count,
252 u64 ceiling)
253{
254 struct stm32_lptim_cnt *const priv = counter_priv(counter);
255
256 if (stm32_lptim_is_enabled(priv))
257 return -EBUSY;
258
259 if (ceiling > STM32_LPTIM_MAX_ARR)
260 return -ERANGE;
261
262 priv->ceiling = ceiling;
263
264 return 0;
265}
266
267static struct counter_comp stm32_lptim_cnt_ext[] = {
268 COUNTER_COMP_ENABLE(stm32_lptim_cnt_enable_read,
269 stm32_lptim_cnt_enable_write),
270 COUNTER_COMP_CEILING(stm32_lptim_cnt_ceiling_read,
271 stm32_lptim_cnt_ceiling_write),
272};
273
274static int stm32_lptim_cnt_action_read(struct counter_device *counter,
275 struct counter_count *count,
276 struct counter_synapse *synapse,
277 enum counter_synapse_action *action)
278{
279 struct stm32_lptim_cnt *const priv = counter_priv(counter);
280 enum counter_function function;
281 int err;
282
283 err = stm32_lptim_cnt_function_read(counter, count, &function);
284 if (err)
285 return err;
286
287 switch (function) {
288 case COUNTER_FUNCTION_INCREASE:
289 /* LP Timer acts as up-counter on input 1 */
290 if (synapse->signal->id != count->synapses[0].signal->id) {
291 *action = COUNTER_SYNAPSE_ACTION_NONE;
292 return 0;
293 }
294
295 switch (priv->polarity) {
296 case STM32_LPTIM_CKPOL_RISING_EDGE:
297 *action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
298 return 0;
299 case STM32_LPTIM_CKPOL_FALLING_EDGE:
300 *action = COUNTER_SYNAPSE_ACTION_FALLING_EDGE;
301 return 0;
302 case STM32_LPTIM_CKPOL_BOTH_EDGES:
303 *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
304 return 0;
305 default:
306 /* should never reach this path */
307 return -EINVAL;
308 }
309 case COUNTER_FUNCTION_QUADRATURE_X4:
310 *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
311 return 0;
312 default:
313 /* should never reach this path */
314 return -EINVAL;
315 }
316}
317
318static int stm32_lptim_cnt_action_write(struct counter_device *counter,
319 struct counter_count *count,
320 struct counter_synapse *synapse,
321 enum counter_synapse_action action)
322{
323 struct stm32_lptim_cnt *const priv = counter_priv(counter);
324 enum counter_function function;
325 int err;
326
327 if (stm32_lptim_is_enabled(priv))
328 return -EBUSY;
329
330 err = stm32_lptim_cnt_function_read(counter, count, &function);
331 if (err)
332 return err;
333
334 /* only set polarity when in counter mode (on input 1) */
335 if (function != COUNTER_FUNCTION_INCREASE
336 || synapse->signal->id != count->synapses[0].signal->id)
337 return -EINVAL;
338
339 switch (action) {
340 case COUNTER_SYNAPSE_ACTION_RISING_EDGE:
341 priv->polarity = STM32_LPTIM_CKPOL_RISING_EDGE;
342 return 0;
343 case COUNTER_SYNAPSE_ACTION_FALLING_EDGE:
344 priv->polarity = STM32_LPTIM_CKPOL_FALLING_EDGE;
345 return 0;
346 case COUNTER_SYNAPSE_ACTION_BOTH_EDGES:
347 priv->polarity = STM32_LPTIM_CKPOL_BOTH_EDGES;
348 return 0;
349 default:
350 return -EINVAL;
351 }
352}
353
354static const struct counter_ops stm32_lptim_cnt_ops = {
355 .count_read = stm32_lptim_cnt_read,
356 .function_read = stm32_lptim_cnt_function_read,
357 .function_write = stm32_lptim_cnt_function_write,
358 .action_read = stm32_lptim_cnt_action_read,
359 .action_write = stm32_lptim_cnt_action_write,
360};
361
362static struct counter_signal stm32_lptim_cnt_signals[] = {
363 {
364 .id = 0,
365 .name = "Channel 1 Quadrature A"
366 },
367 {
368 .id = 1,
369 .name = "Channel 1 Quadrature B"
370 }
371};
372
373static struct counter_synapse stm32_lptim_cnt_synapses[] = {
374 {
375 .actions_list = stm32_lptim_cnt_synapse_actions,
376 .num_actions = ARRAY_SIZE(stm32_lptim_cnt_synapse_actions),
377 .signal = &stm32_lptim_cnt_signals[0]
378 },
379 {
380 .actions_list = stm32_lptim_cnt_synapse_actions,
381 .num_actions = ARRAY_SIZE(stm32_lptim_cnt_synapse_actions),
382 .signal = &stm32_lptim_cnt_signals[1]
383 }
384};
385
386/* LP timer with encoder */
387static struct counter_count stm32_lptim_enc_counts = {
388 .id = 0,
389 .name = "LPTimer Count",
390 .functions_list = stm32_lptim_cnt_functions,
391 .num_functions = ARRAY_SIZE(stm32_lptim_cnt_functions),
392 .synapses = stm32_lptim_cnt_synapses,
393 .num_synapses = ARRAY_SIZE(stm32_lptim_cnt_synapses),
394 .ext = stm32_lptim_cnt_ext,
395 .num_ext = ARRAY_SIZE(stm32_lptim_cnt_ext)
396};
397
398/* LP timer without encoder (counter only) */
399static struct counter_count stm32_lptim_in1_counts = {
400 .id = 0,
401 .name = "LPTimer Count",
402 .functions_list = stm32_lptim_cnt_functions,
403 .num_functions = 1,
404 .synapses = stm32_lptim_cnt_synapses,
405 .num_synapses = 1,
406 .ext = stm32_lptim_cnt_ext,
407 .num_ext = ARRAY_SIZE(stm32_lptim_cnt_ext)
408};
409
410static int stm32_lptim_cnt_probe(struct platform_device *pdev)
411{
412 struct stm32_lptimer *ddata = dev_get_drvdata(pdev->dev.parent);
413 struct counter_device *counter;
414 struct stm32_lptim_cnt *priv;
415 int ret;
416
417 if (IS_ERR_OR_NULL(ddata))
418 return -EINVAL;
419
420 counter = devm_counter_alloc(&pdev->dev, sizeof(*priv));
421 if (!counter)
422 return -ENOMEM;
423 priv = counter_priv(counter);
424
425 priv->dev = &pdev->dev;
426 priv->regmap = ddata->regmap;
427 priv->clk = ddata->clk;
428 priv->ceiling = STM32_LPTIM_MAX_ARR;
429
430 /* Initialize Counter device */
431 counter->name = dev_name(&pdev->dev);
432 counter->parent = &pdev->dev;
433 counter->ops = &stm32_lptim_cnt_ops;
434 if (ddata->has_encoder) {
435 counter->counts = &stm32_lptim_enc_counts;
436 counter->num_signals = ARRAY_SIZE(stm32_lptim_cnt_signals);
437 } else {
438 counter->counts = &stm32_lptim_in1_counts;
439 counter->num_signals = 1;
440 }
441 counter->num_counts = 1;
442 counter->signals = stm32_lptim_cnt_signals;
443
444 platform_set_drvdata(pdev, priv);
445
446 ret = devm_counter_add(&pdev->dev, counter);
447 if (ret < 0)
448 return dev_err_probe(&pdev->dev, ret, "Failed to add counter\n");
449
450 return 0;
451}
452
453#ifdef CONFIG_PM_SLEEP
454static int stm32_lptim_cnt_suspend(struct device *dev)
455{
456 struct stm32_lptim_cnt *priv = dev_get_drvdata(dev);
457 int ret;
458
459 /* Only take care of enabled counter: don't disturb other MFD child */
460 if (priv->enabled) {
461 ret = stm32_lptim_setup(priv, 0);
462 if (ret)
463 return ret;
464
465 ret = stm32_lptim_set_enable_state(priv, 0);
466 if (ret)
467 return ret;
468
469 /* Force enable state for later resume */
470 priv->enabled = true;
471 }
472
473 return pinctrl_pm_select_sleep_state(dev);
474}
475
476static int stm32_lptim_cnt_resume(struct device *dev)
477{
478 struct stm32_lptim_cnt *priv = dev_get_drvdata(dev);
479 int ret;
480
481 ret = pinctrl_pm_select_default_state(dev);
482 if (ret)
483 return ret;
484
485 if (priv->enabled) {
486 priv->enabled = false;
487 ret = stm32_lptim_setup(priv, 1);
488 if (ret)
489 return ret;
490
491 ret = stm32_lptim_set_enable_state(priv, 1);
492 if (ret)
493 return ret;
494 }
495
496 return 0;
497}
498#endif
499
500static SIMPLE_DEV_PM_OPS(stm32_lptim_cnt_pm_ops, stm32_lptim_cnt_suspend,
501 stm32_lptim_cnt_resume);
502
503static const struct of_device_id stm32_lptim_cnt_of_match[] = {
504 { .compatible = "st,stm32-lptimer-counter", },
505 {},
506};
507MODULE_DEVICE_TABLE(of, stm32_lptim_cnt_of_match);
508
509static struct platform_driver stm32_lptim_cnt_driver = {
510 .probe = stm32_lptim_cnt_probe,
511 .driver = {
512 .name = "stm32-lptimer-counter",
513 .of_match_table = stm32_lptim_cnt_of_match,
514 .pm = &stm32_lptim_cnt_pm_ops,
515 },
516};
517module_platform_driver(stm32_lptim_cnt_driver);
518
519MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
520MODULE_ALIAS("platform:stm32-lptimer-counter");
521MODULE_DESCRIPTION("STMicroelectronics STM32 LPTIM counter driver");
522MODULE_LICENSE("GPL v2");
523MODULE_IMPORT_NS(COUNTER);
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
21struct 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
32static 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
44static 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
94static 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
110static 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
139static 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
184static 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
189static const char *const stm32_lptim_quadrature_modes[] = {
190 "non-quadrature",
191 "quadrature",
192};
193
194static 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
202static 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
216static 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
223static const char * const stm32_lptim_cnt_polarity[] = {
224 "rising-edge", "falling-edge", "both-edges",
225};
226
227static 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
235static 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
249static 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
256static 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
262static 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
280static 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
290static 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 */
301static 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
316static 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) */
327static 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
339static 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 */
354enum stm32_lptim_cnt_function {
355 STM32_LPTIM_COUNTER_INCREASE,
356 STM32_LPTIM_ENCODER_BOTH_EDGE,
357};
358
359static 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
364enum 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
371static 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
379static 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
396static 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
415static 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
437static 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
451static 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
482static 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
491static 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
501static 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
514static 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
543static 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
574static 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
582static 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
593static 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 */
607static 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) */
619static 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
630static 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
686static 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
708static 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
732static SIMPLE_DEV_PM_OPS(stm32_lptim_cnt_pm_ops, stm32_lptim_cnt_suspend,
733 stm32_lptim_cnt_resume);
734
735static const struct of_device_id stm32_lptim_cnt_of_match[] = {
736 { .compatible = "st,stm32-lptimer-counter", },
737 {},
738};
739MODULE_DEVICE_TABLE(of, stm32_lptim_cnt_of_match);
740
741static 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};
749module_platform_driver(stm32_lptim_cnt_driver);
750
751MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
752MODULE_ALIAS("platform:stm32-lptimer-counter");
753MODULE_DESCRIPTION("STMicroelectronics STM32 LPTIM counter driver");
754MODULE_LICENSE("GPL v2");