1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * SuperH Timer Support - MTU2
4 *
5 * Copyright (C) 2009 Magnus Damm
6 */
7
8 #include <linux/clk.h>
9 #include <linux/clockchips.h>
10 #include <linux/delay.h>
11 #include <linux/err.h>
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
14 #include <linux/io.h>
15 #include <linux/ioport.h>
16 #include <linux/irq.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/platform_device.h>
20 #include <linux/pm_domain.h>
21 #include <linux/pm_runtime.h>
22 #include <linux/sh_timer.h>
23 #include <linux/slab.h>
24 #include <linux/spinlock.h>
25
26 #ifdef CONFIG_SUPERH
27 #include <asm/platform_early.h>
28 #endif
29
30 struct sh_mtu2_device;
31
32 struct sh_mtu2_channel {
33 struct sh_mtu2_device *mtu;
34 unsigned int index;
35
36 void __iomem *base;
37
38 struct clock_event_device ced;
39 };
40
41 struct sh_mtu2_device {
42 struct platform_device *pdev;
43
44 void __iomem *mapbase;
45 struct clk *clk;
46
47 raw_spinlock_t lock; /* Protect the shared registers */
48
49 struct sh_mtu2_channel *channels;
50 unsigned int num_channels;
51
52 bool has_clockevent;
53 };
54
55 #define TSTR -1 /* shared register */
56 #define TCR 0 /* channel register */
57 #define TMDR 1 /* channel register */
58 #define TIOR 2 /* channel register */
59 #define TIER 3 /* channel register */
60 #define TSR 4 /* channel register */
61 #define TCNT 5 /* channel register */
62 #define TGR 6 /* channel register */
63
64 #define TCR_CCLR_NONE (0 << 5)
65 #define TCR_CCLR_TGRA (1 << 5)
66 #define TCR_CCLR_TGRB (2 << 5)
67 #define TCR_CCLR_SYNC (3 << 5)
68 #define TCR_CCLR_TGRC (5 << 5)
69 #define TCR_CCLR_TGRD (6 << 5)
70 #define TCR_CCLR_MASK (7 << 5)
71 #define TCR_CKEG_RISING (0 << 3)
72 #define TCR_CKEG_FALLING (1 << 3)
73 #define TCR_CKEG_BOTH (2 << 3)
74 #define TCR_CKEG_MASK (3 << 3)
75 /* Values 4 to 7 are channel-dependent */
76 #define TCR_TPSC_P1 (0 << 0)
77 #define TCR_TPSC_P4 (1 << 0)
78 #define TCR_TPSC_P16 (2 << 0)
79 #define TCR_TPSC_P64 (3 << 0)
80 #define TCR_TPSC_CH0_TCLKA (4 << 0)
81 #define TCR_TPSC_CH0_TCLKB (5 << 0)
82 #define TCR_TPSC_CH0_TCLKC (6 << 0)
83 #define TCR_TPSC_CH0_TCLKD (7 << 0)
84 #define TCR_TPSC_CH1_TCLKA (4 << 0)
85 #define TCR_TPSC_CH1_TCLKB (5 << 0)
86 #define TCR_TPSC_CH1_P256 (6 << 0)
87 #define TCR_TPSC_CH1_TCNT2 (7 << 0)
88 #define TCR_TPSC_CH2_TCLKA (4 << 0)
89 #define TCR_TPSC_CH2_TCLKB (5 << 0)
90 #define TCR_TPSC_CH2_TCLKC (6 << 0)
91 #define TCR_TPSC_CH2_P1024 (7 << 0)
92 #define TCR_TPSC_CH34_P256 (4 << 0)
93 #define TCR_TPSC_CH34_P1024 (5 << 0)
94 #define TCR_TPSC_CH34_TCLKA (6 << 0)
95 #define TCR_TPSC_CH34_TCLKB (7 << 0)
96 #define TCR_TPSC_MASK (7 << 0)
97
98 #define TMDR_BFE (1 << 6)
99 #define TMDR_BFB (1 << 5)
100 #define TMDR_BFA (1 << 4)
101 #define TMDR_MD_NORMAL (0 << 0)
102 #define TMDR_MD_PWM_1 (2 << 0)
103 #define TMDR_MD_PWM_2 (3 << 0)
104 #define TMDR_MD_PHASE_1 (4 << 0)
105 #define TMDR_MD_PHASE_2 (5 << 0)
106 #define TMDR_MD_PHASE_3 (6 << 0)
107 #define TMDR_MD_PHASE_4 (7 << 0)
108 #define TMDR_MD_PWM_SYNC (8 << 0)
109 #define TMDR_MD_PWM_COMP_CREST (13 << 0)
110 #define TMDR_MD_PWM_COMP_TROUGH (14 << 0)
111 #define TMDR_MD_PWM_COMP_BOTH (15 << 0)
112 #define TMDR_MD_MASK (15 << 0)
113
114 #define TIOC_IOCH(n) ((n) << 4)
115 #define TIOC_IOCL(n) ((n) << 0)
116 #define TIOR_OC_RETAIN (0 << 0)
117 #define TIOR_OC_0_CLEAR (1 << 0)
118 #define TIOR_OC_0_SET (2 << 0)
119 #define TIOR_OC_0_TOGGLE (3 << 0)
120 #define TIOR_OC_1_CLEAR (5 << 0)
121 #define TIOR_OC_1_SET (6 << 0)
122 #define TIOR_OC_1_TOGGLE (7 << 0)
123 #define TIOR_IC_RISING (8 << 0)
124 #define TIOR_IC_FALLING (9 << 0)
125 #define TIOR_IC_BOTH (10 << 0)
126 #define TIOR_IC_TCNT (12 << 0)
127 #define TIOR_MASK (15 << 0)
128
129 #define TIER_TTGE (1 << 7)
130 #define TIER_TTGE2 (1 << 6)
131 #define TIER_TCIEU (1 << 5)
132 #define TIER_TCIEV (1 << 4)
133 #define TIER_TGIED (1 << 3)
134 #define TIER_TGIEC (1 << 2)
135 #define TIER_TGIEB (1 << 1)
136 #define TIER_TGIEA (1 << 0)
137
138 #define TSR_TCFD (1 << 7)
139 #define TSR_TCFU (1 << 5)
140 #define TSR_TCFV (1 << 4)
141 #define TSR_TGFD (1 << 3)
142 #define TSR_TGFC (1 << 2)
143 #define TSR_TGFB (1 << 1)
144 #define TSR_TGFA (1 << 0)
145
146 static unsigned long mtu2_reg_offs[] = {
147 [TCR] = 0,
148 [TMDR] = 1,
149 [TIOR] = 2,
150 [TIER] = 4,
151 [TSR] = 5,
152 [TCNT] = 6,
153 [TGR] = 8,
154 };
155
sh_mtu2_read(struct sh_mtu2_channel * ch,int reg_nr)156 static inline unsigned long sh_mtu2_read(struct sh_mtu2_channel *ch, int reg_nr)
157 {
158 unsigned long offs;
159
160 if (reg_nr == TSTR)
161 return ioread8(ch->mtu->mapbase + 0x280);
162
163 offs = mtu2_reg_offs[reg_nr];
164
165 if ((reg_nr == TCNT) || (reg_nr == TGR))
166 return ioread16(ch->base + offs);
167 else
168 return ioread8(ch->base + offs);
169 }
170
sh_mtu2_write(struct sh_mtu2_channel * ch,int reg_nr,unsigned long value)171 static inline void sh_mtu2_write(struct sh_mtu2_channel *ch, int reg_nr,
172 unsigned long value)
173 {
174 unsigned long offs;
175
176 if (reg_nr == TSTR)
177 return iowrite8(value, ch->mtu->mapbase + 0x280);
178
179 offs = mtu2_reg_offs[reg_nr];
180
181 if ((reg_nr == TCNT) || (reg_nr == TGR))
182 iowrite16(value, ch->base + offs);
183 else
184 iowrite8(value, ch->base + offs);
185 }
186
sh_mtu2_start_stop_ch(struct sh_mtu2_channel * ch,int start)187 static void sh_mtu2_start_stop_ch(struct sh_mtu2_channel *ch, int start)
188 {
189 unsigned long flags, value;
190
191 /* start stop register shared by multiple timer channels */
192 raw_spin_lock_irqsave(&ch->mtu->lock, flags);
193 value = sh_mtu2_read(ch, TSTR);
194
195 if (start)
196 value |= 1 << ch->index;
197 else
198 value &= ~(1 << ch->index);
199
200 sh_mtu2_write(ch, TSTR, value);
201 raw_spin_unlock_irqrestore(&ch->mtu->lock, flags);
202 }
203
sh_mtu2_enable(struct sh_mtu2_channel * ch)204 static int sh_mtu2_enable(struct sh_mtu2_channel *ch)
205 {
206 unsigned long periodic;
207 unsigned long rate;
208 int ret;
209
210 pm_runtime_get_sync(&ch->mtu->pdev->dev);
211 dev_pm_syscore_device(&ch->mtu->pdev->dev, true);
212
213 /* enable clock */
214 ret = clk_enable(ch->mtu->clk);
215 if (ret) {
216 dev_err(&ch->mtu->pdev->dev, "ch%u: cannot enable clock\n",
217 ch->index);
218 return ret;
219 }
220
221 /* make sure channel is disabled */
222 sh_mtu2_start_stop_ch(ch, 0);
223
224 rate = clk_get_rate(ch->mtu->clk) / 64;
225 periodic = (rate + HZ/2) / HZ;
226
227 /*
228 * "Periodic Counter Operation"
229 * Clear on TGRA compare match, divide clock by 64.
230 */
231 sh_mtu2_write(ch, TCR, TCR_CCLR_TGRA | TCR_TPSC_P64);
232 sh_mtu2_write(ch, TIOR, TIOC_IOCH(TIOR_OC_0_CLEAR) |
233 TIOC_IOCL(TIOR_OC_0_CLEAR));
234 sh_mtu2_write(ch, TGR, periodic);
235 sh_mtu2_write(ch, TCNT, 0);
236 sh_mtu2_write(ch, TMDR, TMDR_MD_NORMAL);
237 sh_mtu2_write(ch, TIER, TIER_TGIEA);
238
239 /* enable channel */
240 sh_mtu2_start_stop_ch(ch, 1);
241
242 return 0;
243 }
244
sh_mtu2_disable(struct sh_mtu2_channel * ch)245 static void sh_mtu2_disable(struct sh_mtu2_channel *ch)
246 {
247 /* disable channel */
248 sh_mtu2_start_stop_ch(ch, 0);
249
250 /* stop clock */
251 clk_disable(ch->mtu->clk);
252
253 dev_pm_syscore_device(&ch->mtu->pdev->dev, false);
254 pm_runtime_put(&ch->mtu->pdev->dev);
255 }
256
sh_mtu2_interrupt(int irq,void * dev_id)257 static irqreturn_t sh_mtu2_interrupt(int irq, void *dev_id)
258 {
259 struct sh_mtu2_channel *ch = dev_id;
260
261 /* acknowledge interrupt */
262 sh_mtu2_read(ch, TSR);
263 sh_mtu2_write(ch, TSR, ~TSR_TGFA);
264
265 /* notify clockevent layer */
266 ch->ced.event_handler(&ch->ced);
267 return IRQ_HANDLED;
268 }
269
ced_to_sh_mtu2(struct clock_event_device * ced)270 static struct sh_mtu2_channel *ced_to_sh_mtu2(struct clock_event_device *ced)
271 {
272 return container_of(ced, struct sh_mtu2_channel, ced);
273 }
274
sh_mtu2_clock_event_shutdown(struct clock_event_device * ced)275 static int sh_mtu2_clock_event_shutdown(struct clock_event_device *ced)
276 {
277 struct sh_mtu2_channel *ch = ced_to_sh_mtu2(ced);
278
279 if (clockevent_state_periodic(ced))
280 sh_mtu2_disable(ch);
281
282 return 0;
283 }
284
sh_mtu2_clock_event_set_periodic(struct clock_event_device * ced)285 static int sh_mtu2_clock_event_set_periodic(struct clock_event_device *ced)
286 {
287 struct sh_mtu2_channel *ch = ced_to_sh_mtu2(ced);
288
289 if (clockevent_state_periodic(ced))
290 sh_mtu2_disable(ch);
291
292 dev_info(&ch->mtu->pdev->dev, "ch%u: used for periodic clock events\n",
293 ch->index);
294 sh_mtu2_enable(ch);
295 return 0;
296 }
297
sh_mtu2_clock_event_suspend(struct clock_event_device * ced)298 static void sh_mtu2_clock_event_suspend(struct clock_event_device *ced)
299 {
300 dev_pm_genpd_suspend(&ced_to_sh_mtu2(ced)->mtu->pdev->dev);
301 }
302
sh_mtu2_clock_event_resume(struct clock_event_device * ced)303 static void sh_mtu2_clock_event_resume(struct clock_event_device *ced)
304 {
305 dev_pm_genpd_resume(&ced_to_sh_mtu2(ced)->mtu->pdev->dev);
306 }
307
sh_mtu2_register_clockevent(struct sh_mtu2_channel * ch,const char * name)308 static void sh_mtu2_register_clockevent(struct sh_mtu2_channel *ch,
309 const char *name)
310 {
311 struct clock_event_device *ced = &ch->ced;
312
313 ced->name = name;
314 ced->features = CLOCK_EVT_FEAT_PERIODIC;
315 ced->rating = 200;
316 ced->cpumask = cpu_possible_mask;
317 ced->set_state_shutdown = sh_mtu2_clock_event_shutdown;
318 ced->set_state_periodic = sh_mtu2_clock_event_set_periodic;
319 ced->suspend = sh_mtu2_clock_event_suspend;
320 ced->resume = sh_mtu2_clock_event_resume;
321
322 dev_info(&ch->mtu->pdev->dev, "ch%u: used for clock events\n",
323 ch->index);
324 clockevents_register_device(ced);
325 }
326
sh_mtu2_register(struct sh_mtu2_channel * ch,const char * name)327 static int sh_mtu2_register(struct sh_mtu2_channel *ch, const char *name)
328 {
329 ch->mtu->has_clockevent = true;
330 sh_mtu2_register_clockevent(ch, name);
331
332 return 0;
333 }
334
335 static const unsigned int sh_mtu2_channel_offsets[] = {
336 0x300, 0x380, 0x000,
337 };
338
sh_mtu2_setup_channel(struct sh_mtu2_channel * ch,unsigned int index,struct sh_mtu2_device * mtu)339 static int sh_mtu2_setup_channel(struct sh_mtu2_channel *ch, unsigned int index,
340 struct sh_mtu2_device *mtu)
341 {
342 char name[6];
343 int irq;
344 int ret;
345
346 ch->mtu = mtu;
347
348 sprintf(name, "tgi%ua", index);
349 irq = platform_get_irq_byname(mtu->pdev, name);
350 if (irq < 0) {
351 /* Skip channels with no declared interrupt. */
352 return 0;
353 }
354
355 ret = request_irq(irq, sh_mtu2_interrupt,
356 IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING,
357 dev_name(&ch->mtu->pdev->dev), ch);
358 if (ret) {
359 dev_err(&ch->mtu->pdev->dev, "ch%u: failed to request irq %d\n",
360 index, irq);
361 return ret;
362 }
363
364 ch->base = mtu->mapbase + sh_mtu2_channel_offsets[index];
365 ch->index = index;
366
367 return sh_mtu2_register(ch, dev_name(&mtu->pdev->dev));
368 }
369
sh_mtu2_map_memory(struct sh_mtu2_device * mtu)370 static int sh_mtu2_map_memory(struct sh_mtu2_device *mtu)
371 {
372 struct resource *res;
373
374 res = platform_get_resource(mtu->pdev, IORESOURCE_MEM, 0);
375 if (!res) {
376 dev_err(&mtu->pdev->dev, "failed to get I/O memory\n");
377 return -ENXIO;
378 }
379
380 mtu->mapbase = ioremap(res->start, resource_size(res));
381 if (mtu->mapbase == NULL)
382 return -ENXIO;
383
384 return 0;
385 }
386
sh_mtu2_setup(struct sh_mtu2_device * mtu,struct platform_device * pdev)387 static int sh_mtu2_setup(struct sh_mtu2_device *mtu,
388 struct platform_device *pdev)
389 {
390 unsigned int i;
391 int ret;
392
393 mtu->pdev = pdev;
394
395 raw_spin_lock_init(&mtu->lock);
396
397 /* Get hold of clock. */
398 mtu->clk = clk_get(&mtu->pdev->dev, "fck");
399 if (IS_ERR(mtu->clk)) {
400 dev_err(&mtu->pdev->dev, "cannot get clock\n");
401 return PTR_ERR(mtu->clk);
402 }
403
404 ret = clk_prepare(mtu->clk);
405 if (ret < 0)
406 goto err_clk_put;
407
408 /* Map the memory resource. */
409 ret = sh_mtu2_map_memory(mtu);
410 if (ret < 0) {
411 dev_err(&mtu->pdev->dev, "failed to remap I/O memory\n");
412 goto err_clk_unprepare;
413 }
414
415 /* Allocate and setup the channels. */
416 ret = platform_irq_count(pdev);
417 if (ret < 0)
418 goto err_unmap;
419
420 mtu->num_channels = min_t(unsigned int, ret,
421 ARRAY_SIZE(sh_mtu2_channel_offsets));
422
423 mtu->channels = kcalloc(mtu->num_channels, sizeof(*mtu->channels),
424 GFP_KERNEL);
425 if (mtu->channels == NULL) {
426 ret = -ENOMEM;
427 goto err_unmap;
428 }
429
430 for (i = 0; i < mtu->num_channels; ++i) {
431 ret = sh_mtu2_setup_channel(&mtu->channels[i], i, mtu);
432 if (ret < 0)
433 goto err_unmap;
434 }
435
436 platform_set_drvdata(pdev, mtu);
437
438 return 0;
439
440 err_unmap:
441 kfree(mtu->channels);
442 iounmap(mtu->mapbase);
443 err_clk_unprepare:
444 clk_unprepare(mtu->clk);
445 err_clk_put:
446 clk_put(mtu->clk);
447 return ret;
448 }
449
sh_mtu2_probe(struct platform_device * pdev)450 static int sh_mtu2_probe(struct platform_device *pdev)
451 {
452 struct sh_mtu2_device *mtu = platform_get_drvdata(pdev);
453 int ret;
454
455 if (!is_sh_early_platform_device(pdev)) {
456 pm_runtime_set_active(&pdev->dev);
457 pm_runtime_enable(&pdev->dev);
458 }
459
460 if (mtu) {
461 dev_info(&pdev->dev, "kept as earlytimer\n");
462 goto out;
463 }
464
465 mtu = kzalloc(sizeof(*mtu), GFP_KERNEL);
466 if (mtu == NULL)
467 return -ENOMEM;
468
469 ret = sh_mtu2_setup(mtu, pdev);
470 if (ret) {
471 kfree(mtu);
472 pm_runtime_idle(&pdev->dev);
473 return ret;
474 }
475 if (is_sh_early_platform_device(pdev))
476 return 0;
477
478 out:
479 if (mtu->has_clockevent)
480 pm_runtime_irq_safe(&pdev->dev);
481 else
482 pm_runtime_idle(&pdev->dev);
483
484 return 0;
485 }
486
487 static const struct platform_device_id sh_mtu2_id_table[] = {
488 { "sh-mtu2", 0 },
489 { },
490 };
491 MODULE_DEVICE_TABLE(platform, sh_mtu2_id_table);
492
493 static const struct of_device_id sh_mtu2_of_table[] __maybe_unused = {
494 { .compatible = "renesas,mtu2" },
495 { }
496 };
497 MODULE_DEVICE_TABLE(of, sh_mtu2_of_table);
498
499 static struct platform_driver sh_mtu2_device_driver = {
500 .probe = sh_mtu2_probe,
501 .driver = {
502 .name = "sh_mtu2",
503 .of_match_table = of_match_ptr(sh_mtu2_of_table),
504 .suppress_bind_attrs = true,
505 },
506 .id_table = sh_mtu2_id_table,
507 };
508
sh_mtu2_init(void)509 static int __init sh_mtu2_init(void)
510 {
511 return platform_driver_register(&sh_mtu2_device_driver);
512 }
513
sh_mtu2_exit(void)514 static void __exit sh_mtu2_exit(void)
515 {
516 platform_driver_unregister(&sh_mtu2_device_driver);
517 }
518
519 #ifdef CONFIG_SUPERH
520 sh_early_platform_init("earlytimer", &sh_mtu2_device_driver);
521 #endif
522
523 subsys_initcall(sh_mtu2_init);
524 module_exit(sh_mtu2_exit);
525
526 MODULE_AUTHOR("Magnus Damm");
527 MODULE_DESCRIPTION("SuperH MTU2 Timer Driver");
528