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perf/x86/uncore: Correct the number of CHAs on EMR
[tomoyo/tomoyo-test1.git] / drivers / pwm / pwm-rz-mtu3.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Renesas RZ/G2L MTU3a PWM Timer driver
4  *
5  * Copyright (C) 2023 Renesas Electronics Corporation
6  *
7  * Hardware manual for this IP can be found here
8  * https://www.renesas.com/eu/en/document/mah/rzg2l-group-rzg2lc-group-users-manual-hardware-0?language=en
9  *
10  * Limitations:
11  * - When PWM is disabled, the output is driven to Hi-Z.
12  * - While the hardware supports both polarities, the driver (for now)
13  *   only handles normal polarity.
14  * - HW uses one counter and two match components to configure duty_cycle
15  *   and period.
16  * - Multi-Function Timer Pulse Unit (a.k.a MTU) has 7 HW channels for PWM
17  *   operations. (The channels are MTU{0..4, 6, 7}.)
18  * - MTU{1, 2} channels have a single IO, whereas all other HW channels have
19  *   2 IOs.
20  * - Each IO is modelled as an independent PWM channel.
21  * - rz_mtu3_channel_io_map table is used to map the PWM channel to the
22  *   corresponding HW channel as there are difference in number of IOs
23  *   between HW channels.
24  */
25
26 #include <linux/bitfield.h>
27 #include <linux/clk.h>
28 #include <linux/limits.h>
29 #include <linux/mfd/rz-mtu3.h>
30 #include <linux/module.h>
31 #include <linux/platform_device.h>
32 #include <linux/pm_runtime.h>
33 #include <linux/pwm.h>
34 #include <linux/time.h>
35
36 #define RZ_MTU3_MAX_PWM_CHANNELS        12
37 #define RZ_MTU3_MAX_HW_CHANNELS         7
38
39 /**
40  * struct rz_mtu3_channel_io_map - MTU3 pwm channel map
41  *
42  * @base_pwm_number: First PWM of a channel
43  * @num: number of IOs on the HW channel.
44  */
45 struct rz_mtu3_channel_io_map {
46         u8 base_pwm_number;
47         u8 num_channel_ios;
48 };
49
50 /**
51  * struct rz_mtu3_pwm_channel - MTU3 pwm channel data
52  *
53  * @mtu: MTU3 channel data
54  * @map: MTU3 pwm channel map
55  */
56 struct rz_mtu3_pwm_channel {
57         struct rz_mtu3_channel *mtu;
58         const struct rz_mtu3_channel_io_map *map;
59 };
60
61 /**
62  * struct rz_mtu3_pwm_chip - MTU3 pwm private data
63  *
64  * @chip: MTU3 pwm chip data
65  * @clk: MTU3 module clock
66  * @lock: Lock to prevent concurrent access for usage count
67  * @rate: MTU3 clock rate
68  * @user_count: MTU3 usage count
69  * @enable_count: MTU3 enable count
70  * @prescale: MTU3 prescale
71  * @channel_data: MTU3 pwm channel data
72  */
73
74 struct rz_mtu3_pwm_chip {
75         struct pwm_chip chip;
76         struct clk *clk;
77         struct mutex lock;
78         unsigned long rate;
79         u32 user_count[RZ_MTU3_MAX_HW_CHANNELS];
80         u32 enable_count[RZ_MTU3_MAX_HW_CHANNELS];
81         u8 prescale[RZ_MTU3_MAX_HW_CHANNELS];
82         struct rz_mtu3_pwm_channel channel_data[RZ_MTU3_MAX_HW_CHANNELS];
83 };
84
85 /*
86  * The MTU channels are {0..4, 6, 7} and the number of IO on MTU1
87  * and MTU2 channel is 1 compared to 2 on others.
88  */
89 static const struct rz_mtu3_channel_io_map channel_map[] = {
90         { 0, 2 }, { 2, 1 }, { 3, 1 }, { 4, 2 }, { 6, 2 }, { 8, 2 }, { 10, 2 }
91 };
92
93 static inline struct rz_mtu3_pwm_chip *to_rz_mtu3_pwm_chip(struct pwm_chip *chip)
94 {
95         return container_of(chip, struct rz_mtu3_pwm_chip, chip);
96 }
97
98 static void rz_mtu3_pwm_read_tgr_registers(struct rz_mtu3_pwm_channel *priv,
99                                            u16 reg_pv_offset, u16 *pv_val,
100                                            u16 reg_dc_offset, u16 *dc_val)
101 {
102         *pv_val = rz_mtu3_16bit_ch_read(priv->mtu, reg_pv_offset);
103         *dc_val = rz_mtu3_16bit_ch_read(priv->mtu, reg_dc_offset);
104 }
105
106 static void rz_mtu3_pwm_write_tgr_registers(struct rz_mtu3_pwm_channel *priv,
107                                             u16 reg_pv_offset, u16 pv_val,
108                                             u16 reg_dc_offset, u16 dc_val)
109 {
110         rz_mtu3_16bit_ch_write(priv->mtu, reg_pv_offset, pv_val);
111         rz_mtu3_16bit_ch_write(priv->mtu, reg_dc_offset, dc_val);
112 }
113
114 static u8 rz_mtu3_pwm_calculate_prescale(struct rz_mtu3_pwm_chip *rz_mtu3,
115                                          u64 period_cycles)
116 {
117         u32 prescaled_period_cycles;
118         u8 prescale;
119
120         /*
121          * Supported prescale values are 1, 4, 16 and 64.
122          * TODO: Support prescale values 2, 8, 32, 256 and 1024.
123          */
124         prescaled_period_cycles = period_cycles >> 16;
125         if (prescaled_period_cycles >= 16)
126                 prescale = 3;
127         else
128                 prescale = (fls(prescaled_period_cycles) + 1) / 2;
129
130         return prescale;
131 }
132
133 static struct rz_mtu3_pwm_channel *
134 rz_mtu3_get_channel(struct rz_mtu3_pwm_chip *rz_mtu3_pwm, u32 hwpwm)
135 {
136         struct rz_mtu3_pwm_channel *priv = rz_mtu3_pwm->channel_data;
137         unsigned int ch;
138
139         for (ch = 0; ch < RZ_MTU3_MAX_HW_CHANNELS; ch++, priv++) {
140                 if (priv->map->base_pwm_number + priv->map->num_channel_ios > hwpwm)
141                         break;
142         }
143
144         return priv;
145 }
146
147 static bool rz_mtu3_pwm_is_ch_enabled(struct rz_mtu3_pwm_chip *rz_mtu3_pwm,
148                                       u32 hwpwm)
149 {
150         struct rz_mtu3_pwm_channel *priv;
151         bool is_channel_en;
152         u8 val;
153
154         priv = rz_mtu3_get_channel(rz_mtu3_pwm, hwpwm);
155         is_channel_en = rz_mtu3_is_enabled(priv->mtu);
156         if (!is_channel_en)
157                 return false;
158
159         if (priv->map->base_pwm_number == hwpwm)
160                 val = rz_mtu3_8bit_ch_read(priv->mtu, RZ_MTU3_TIORH);
161         else
162                 val = rz_mtu3_8bit_ch_read(priv->mtu, RZ_MTU3_TIORL);
163
164         return val & RZ_MTU3_TIOR_IOA;
165 }
166
167 static int rz_mtu3_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
168 {
169         struct rz_mtu3_pwm_chip *rz_mtu3_pwm = to_rz_mtu3_pwm_chip(chip);
170         struct rz_mtu3_pwm_channel *priv;
171         bool is_mtu3_channel_available;
172         u32 ch;
173
174         priv = rz_mtu3_get_channel(rz_mtu3_pwm, pwm->hwpwm);
175         ch = priv - rz_mtu3_pwm->channel_data;
176
177         mutex_lock(&rz_mtu3_pwm->lock);
178         /*
179          * Each channel must be requested only once, so if the channel
180          * serves two PWMs and the other is already requested, skip over
181          * rz_mtu3_request_channel()
182          */
183         if (!rz_mtu3_pwm->user_count[ch]) {
184                 is_mtu3_channel_available = rz_mtu3_request_channel(priv->mtu);
185                 if (!is_mtu3_channel_available) {
186                         mutex_unlock(&rz_mtu3_pwm->lock);
187                         return -EBUSY;
188                 }
189         }
190
191         rz_mtu3_pwm->user_count[ch]++;
192         mutex_unlock(&rz_mtu3_pwm->lock);
193
194         return 0;
195 }
196
197 static void rz_mtu3_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
198 {
199         struct rz_mtu3_pwm_chip *rz_mtu3_pwm = to_rz_mtu3_pwm_chip(chip);
200         struct rz_mtu3_pwm_channel *priv;
201         u32 ch;
202
203         priv = rz_mtu3_get_channel(rz_mtu3_pwm, pwm->hwpwm);
204         ch = priv - rz_mtu3_pwm->channel_data;
205
206         mutex_lock(&rz_mtu3_pwm->lock);
207         rz_mtu3_pwm->user_count[ch]--;
208         if (!rz_mtu3_pwm->user_count[ch])
209                 rz_mtu3_release_channel(priv->mtu);
210
211         mutex_unlock(&rz_mtu3_pwm->lock);
212 }
213
214 static int rz_mtu3_pwm_enable(struct rz_mtu3_pwm_chip *rz_mtu3_pwm,
215                               struct pwm_device *pwm)
216 {
217         struct rz_mtu3_pwm_channel *priv;
218         u32 ch;
219         u8 val;
220         int rc;
221
222         rc = pm_runtime_resume_and_get(rz_mtu3_pwm->chip.dev);
223         if (rc)
224                 return rc;
225
226         priv = rz_mtu3_get_channel(rz_mtu3_pwm, pwm->hwpwm);
227         ch = priv - rz_mtu3_pwm->channel_data;
228         val = RZ_MTU3_TIOR_OC_IOB_TOGGLE | RZ_MTU3_TIOR_OC_IOA_H_COMP_MATCH;
229
230         rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TMDR1, RZ_MTU3_TMDR1_MD_PWMMODE1);
231         if (priv->map->base_pwm_number == pwm->hwpwm)
232                 rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TIORH, val);
233         else
234                 rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TIORL, val);
235
236         mutex_lock(&rz_mtu3_pwm->lock);
237         if (!rz_mtu3_pwm->enable_count[ch])
238                 rz_mtu3_enable(priv->mtu);
239
240         rz_mtu3_pwm->enable_count[ch]++;
241         mutex_unlock(&rz_mtu3_pwm->lock);
242
243         return 0;
244 }
245
246 static void rz_mtu3_pwm_disable(struct rz_mtu3_pwm_chip *rz_mtu3_pwm,
247                                 struct pwm_device *pwm)
248 {
249         struct rz_mtu3_pwm_channel *priv;
250         u32 ch;
251
252         priv = rz_mtu3_get_channel(rz_mtu3_pwm, pwm->hwpwm);
253         ch = priv - rz_mtu3_pwm->channel_data;
254
255         /* Disable output pins of MTU3 channel */
256         if (priv->map->base_pwm_number == pwm->hwpwm)
257                 rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TIORH, RZ_MTU3_TIOR_OC_RETAIN);
258         else
259                 rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TIORL, RZ_MTU3_TIOR_OC_RETAIN);
260
261         mutex_lock(&rz_mtu3_pwm->lock);
262         rz_mtu3_pwm->enable_count[ch]--;
263         if (!rz_mtu3_pwm->enable_count[ch])
264                 rz_mtu3_disable(priv->mtu);
265
266         mutex_unlock(&rz_mtu3_pwm->lock);
267
268         pm_runtime_put_sync(rz_mtu3_pwm->chip.dev);
269 }
270
271 static int rz_mtu3_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
272                                  struct pwm_state *state)
273 {
274         struct rz_mtu3_pwm_chip *rz_mtu3_pwm = to_rz_mtu3_pwm_chip(chip);
275         int rc;
276
277         rc = pm_runtime_resume_and_get(chip->dev);
278         if (rc)
279                 return rc;
280
281         state->enabled = rz_mtu3_pwm_is_ch_enabled(rz_mtu3_pwm, pwm->hwpwm);
282         if (state->enabled) {
283                 struct rz_mtu3_pwm_channel *priv;
284                 u8 prescale, val;
285                 u16 dc, pv;
286                 u64 tmp;
287
288                 priv = rz_mtu3_get_channel(rz_mtu3_pwm, pwm->hwpwm);
289                 if (priv->map->base_pwm_number == pwm->hwpwm)
290                         rz_mtu3_pwm_read_tgr_registers(priv, RZ_MTU3_TGRA, &pv,
291                                                        RZ_MTU3_TGRB, &dc);
292                 else
293                         rz_mtu3_pwm_read_tgr_registers(priv, RZ_MTU3_TGRC, &pv,
294                                                        RZ_MTU3_TGRD, &dc);
295
296                 val = rz_mtu3_8bit_ch_read(priv->mtu, RZ_MTU3_TCR);
297                 prescale = FIELD_GET(RZ_MTU3_TCR_TPCS, val);
298
299                 /* With prescale <= 7 and pv <= 0xffff this doesn't overflow. */
300                 tmp = NSEC_PER_SEC * (u64)pv << (2 * prescale);
301                 state->period = DIV_ROUND_UP_ULL(tmp, rz_mtu3_pwm->rate);
302                 tmp = NSEC_PER_SEC * (u64)dc << (2 * prescale);
303                 state->duty_cycle = DIV_ROUND_UP_ULL(tmp, rz_mtu3_pwm->rate);
304
305                 if (state->duty_cycle > state->period)
306                         state->duty_cycle = state->period;
307         }
308
309         state->polarity = PWM_POLARITY_NORMAL;
310         pm_runtime_put(chip->dev);
311
312         return 0;
313 }
314
315 static u16 rz_mtu3_pwm_calculate_pv_or_dc(u64 period_or_duty_cycle, u8 prescale)
316 {
317         return min(period_or_duty_cycle >> (2 * prescale), (u64)U16_MAX);
318 }
319
320 static int rz_mtu3_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
321                               const struct pwm_state *state)
322 {
323         struct rz_mtu3_pwm_chip *rz_mtu3_pwm = to_rz_mtu3_pwm_chip(chip);
324         struct rz_mtu3_pwm_channel *priv;
325         u64 period_cycles;
326         u64 duty_cycles;
327         u8 prescale;
328         u16 pv, dc;
329         u8 val;
330         u32 ch;
331
332         priv = rz_mtu3_get_channel(rz_mtu3_pwm, pwm->hwpwm);
333         ch = priv - rz_mtu3_pwm->channel_data;
334
335         period_cycles = mul_u64_u32_div(state->period, rz_mtu3_pwm->rate,
336                                         NSEC_PER_SEC);
337         prescale = rz_mtu3_pwm_calculate_prescale(rz_mtu3_pwm, period_cycles);
338
339         /*
340          * Prescalar is shared by multiple channels, so prescale can
341          * NOT be modified when there are multiple channels in use with
342          * different settings. Modify prescalar if other PWM is off or handle
343          * it, if current prescale value is less than the one we want to set.
344          */
345         if (rz_mtu3_pwm->enable_count[ch] > 1) {
346                 if (rz_mtu3_pwm->prescale[ch] > prescale)
347                         return -EBUSY;
348
349                 prescale = rz_mtu3_pwm->prescale[ch];
350         }
351
352         pv = rz_mtu3_pwm_calculate_pv_or_dc(period_cycles, prescale);
353
354         duty_cycles = mul_u64_u32_div(state->duty_cycle, rz_mtu3_pwm->rate,
355                                       NSEC_PER_SEC);
356         dc = rz_mtu3_pwm_calculate_pv_or_dc(duty_cycles, prescale);
357
358         /*
359          * If the PWM channel is disabled, make sure to turn on the clock
360          * before writing the register.
361          */
362         if (!pwm->state.enabled) {
363                 int rc;
364
365                 rc = pm_runtime_resume_and_get(chip->dev);
366                 if (rc)
367                         return rc;
368         }
369
370         val = RZ_MTU3_TCR_CKEG_RISING | prescale;
371
372         /* Counter must be stopped while updating TCR register */
373         if (rz_mtu3_pwm->prescale[ch] != prescale && rz_mtu3_pwm->enable_count[ch])
374                 rz_mtu3_disable(priv->mtu);
375
376         if (priv->map->base_pwm_number == pwm->hwpwm) {
377                 rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TCR,
378                                       RZ_MTU3_TCR_CCLR_TGRA | val);
379                 rz_mtu3_pwm_write_tgr_registers(priv, RZ_MTU3_TGRA, pv,
380                                                 RZ_MTU3_TGRB, dc);
381         } else {
382                 rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TCR,
383                                       RZ_MTU3_TCR_CCLR_TGRC | val);
384                 rz_mtu3_pwm_write_tgr_registers(priv, RZ_MTU3_TGRC, pv,
385                                                 RZ_MTU3_TGRD, dc);
386         }
387
388         if (rz_mtu3_pwm->prescale[ch] != prescale) {
389                 /*
390                  * Prescalar is shared by multiple channels, we cache the
391                  * prescalar value from first enabled channel and use the same
392                  * value for both channels.
393                  */
394                 rz_mtu3_pwm->prescale[ch] = prescale;
395
396                 if (rz_mtu3_pwm->enable_count[ch])
397                         rz_mtu3_enable(priv->mtu);
398         }
399
400         /* If the PWM is not enabled, turn the clock off again to save power. */
401         if (!pwm->state.enabled)
402                 pm_runtime_put(chip->dev);
403
404         return 0;
405 }
406
407 static int rz_mtu3_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
408                              const struct pwm_state *state)
409 {
410         struct rz_mtu3_pwm_chip *rz_mtu3_pwm = to_rz_mtu3_pwm_chip(chip);
411         bool enabled = pwm->state.enabled;
412         int ret;
413
414         if (state->polarity != PWM_POLARITY_NORMAL)
415                 return -EINVAL;
416
417         if (!state->enabled) {
418                 if (enabled)
419                         rz_mtu3_pwm_disable(rz_mtu3_pwm, pwm);
420
421                 return 0;
422         }
423
424         mutex_lock(&rz_mtu3_pwm->lock);
425         ret = rz_mtu3_pwm_config(chip, pwm, state);
426         mutex_unlock(&rz_mtu3_pwm->lock);
427         if (ret)
428                 return ret;
429
430         if (!enabled)
431                 ret = rz_mtu3_pwm_enable(rz_mtu3_pwm, pwm);
432
433         return ret;
434 }
435
436 static const struct pwm_ops rz_mtu3_pwm_ops = {
437         .request = rz_mtu3_pwm_request,
438         .free = rz_mtu3_pwm_free,
439         .get_state = rz_mtu3_pwm_get_state,
440         .apply = rz_mtu3_pwm_apply,
441         .owner = THIS_MODULE,
442 };
443
444 static int rz_mtu3_pwm_pm_runtime_suspend(struct device *dev)
445 {
446         struct rz_mtu3_pwm_chip *rz_mtu3_pwm = dev_get_drvdata(dev);
447
448         clk_disable_unprepare(rz_mtu3_pwm->clk);
449
450         return 0;
451 }
452
453 static int rz_mtu3_pwm_pm_runtime_resume(struct device *dev)
454 {
455         struct rz_mtu3_pwm_chip *rz_mtu3_pwm = dev_get_drvdata(dev);
456
457         return clk_prepare_enable(rz_mtu3_pwm->clk);
458 }
459
460 static DEFINE_RUNTIME_DEV_PM_OPS(rz_mtu3_pwm_pm_ops,
461                                  rz_mtu3_pwm_pm_runtime_suspend,
462                                  rz_mtu3_pwm_pm_runtime_resume, NULL);
463
464 static void rz_mtu3_pwm_pm_disable(void *data)
465 {
466         struct rz_mtu3_pwm_chip *rz_mtu3_pwm = data;
467
468         clk_rate_exclusive_put(rz_mtu3_pwm->clk);
469         pm_runtime_disable(rz_mtu3_pwm->chip.dev);
470         pm_runtime_set_suspended(rz_mtu3_pwm->chip.dev);
471 }
472
473 static int rz_mtu3_pwm_probe(struct platform_device *pdev)
474 {
475         struct rz_mtu3 *parent_ddata = dev_get_drvdata(pdev->dev.parent);
476         struct rz_mtu3_pwm_chip *rz_mtu3_pwm;
477         struct device *dev = &pdev->dev;
478         unsigned int i, j = 0;
479         int ret;
480
481         rz_mtu3_pwm = devm_kzalloc(&pdev->dev, sizeof(*rz_mtu3_pwm), GFP_KERNEL);
482         if (!rz_mtu3_pwm)
483                 return -ENOMEM;
484
485         rz_mtu3_pwm->clk = parent_ddata->clk;
486
487         for (i = 0; i < RZ_MTU_NUM_CHANNELS; i++) {
488                 if (i == RZ_MTU3_CHAN_5 || i == RZ_MTU3_CHAN_8)
489                         continue;
490
491                 rz_mtu3_pwm->channel_data[j].mtu = &parent_ddata->channels[i];
492                 rz_mtu3_pwm->channel_data[j].mtu->dev = dev;
493                 rz_mtu3_pwm->channel_data[j].map = &channel_map[j];
494                 j++;
495         }
496
497         mutex_init(&rz_mtu3_pwm->lock);
498         platform_set_drvdata(pdev, rz_mtu3_pwm);
499         ret = clk_prepare_enable(rz_mtu3_pwm->clk);
500         if (ret)
501                 return dev_err_probe(dev, ret, "Clock enable failed\n");
502
503         clk_rate_exclusive_get(rz_mtu3_pwm->clk);
504
505         rz_mtu3_pwm->rate = clk_get_rate(rz_mtu3_pwm->clk);
506         /*
507          * Refuse clk rates > 1 GHz to prevent overflow later for computing
508          * period and duty cycle.
509          */
510         if (rz_mtu3_pwm->rate > NSEC_PER_SEC) {
511                 ret = -EINVAL;
512                 clk_rate_exclusive_put(rz_mtu3_pwm->clk);
513                 goto disable_clock;
514         }
515
516         pm_runtime_set_active(&pdev->dev);
517         pm_runtime_enable(&pdev->dev);
518         rz_mtu3_pwm->chip.dev = &pdev->dev;
519         ret = devm_add_action_or_reset(&pdev->dev, rz_mtu3_pwm_pm_disable,
520                                        rz_mtu3_pwm);
521         if (ret < 0)
522                 return ret;
523
524         rz_mtu3_pwm->chip.ops = &rz_mtu3_pwm_ops;
525         rz_mtu3_pwm->chip.npwm = RZ_MTU3_MAX_PWM_CHANNELS;
526         ret = devm_pwmchip_add(&pdev->dev, &rz_mtu3_pwm->chip);
527         if (ret)
528                 return dev_err_probe(&pdev->dev, ret, "failed to add PWM chip\n");
529
530         pm_runtime_idle(&pdev->dev);
531
532         return 0;
533
534 disable_clock:
535         clk_disable_unprepare(rz_mtu3_pwm->clk);
536         return ret;
537 }
538
539 static struct platform_driver rz_mtu3_pwm_driver = {
540         .driver = {
541                 .name = "pwm-rz-mtu3",
542                 .pm = pm_ptr(&rz_mtu3_pwm_pm_ops),
543         },
544         .probe = rz_mtu3_pwm_probe,
545 };
546 module_platform_driver(rz_mtu3_pwm_driver);
547
548 MODULE_AUTHOR("Biju Das <biju.das.jz@bp.renesas.com>");
549 MODULE_ALIAS("platform:pwm-rz-mtu3");
550 MODULE_DESCRIPTION("Renesas RZ/G2L MTU3a PWM Timer Driver");
551 MODULE_LICENSE("GPL");