1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Ingenic XBurst SoCs SYSOST clocks driver
4 * Copyright (c) 2020 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
5 */
6
7#include <linux/bitfield.h>
8#include <linux/bitops.h>
9#include <linux/clk.h>
10#include <linux/clk-provider.h>
11#include <linux/clockchips.h>
12#include <linux/clocksource.h>
13#include <linux/interrupt.h>
14#include <linux/mfd/syscon.h>
15#include <linux/of_address.h>
16#include <linux/of_irq.h>
17#include <linux/sched_clock.h>
18#include <linux/slab.h>
19#include <linux/syscore_ops.h>
20
21#include <dt-bindings/clock/ingenic,sysost.h>
22
23/* OST register offsets */
24#define OST_REG_OSTCCR 0x00
25#define OST_REG_OSTCR 0x08
26#define OST_REG_OSTFR 0x0c
27#define OST_REG_OSTMR 0x10
28#define OST_REG_OST1DFR 0x14
29#define OST_REG_OST1CNT 0x18
30#define OST_REG_OST2CNTL 0x20
31#define OST_REG_OSTCNT2HBUF 0x24
32#define OST_REG_OSTESR 0x34
33#define OST_REG_OSTECR 0x38
34
35/* bits within the OSTCCR register */
36#define OSTCCR_PRESCALE1_MASK 0x3
37#define OSTCCR_PRESCALE2_MASK 0xc
38
39/* bits within the OSTCR register */
40#define OSTCR_OST1CLR BIT(0)
41#define OSTCR_OST2CLR BIT(1)
42
43/* bits within the OSTFR register */
44#define OSTFR_FFLAG BIT(0)
45
46/* bits within the OSTMR register */
47#define OSTMR_FMASK BIT(0)
48
49/* bits within the OSTESR register */
50#define OSTESR_OST1ENS BIT(0)
51#define OSTESR_OST2ENS BIT(1)
52
53/* bits within the OSTECR register */
54#define OSTECR_OST1ENC BIT(0)
55#define OSTECR_OST2ENC BIT(1)
56
57struct ingenic_soc_info {
58 unsigned int num_channels;
59};
60
61struct ingenic_ost_clk_info {
62 struct clk_init_data init_data;
63 u8 ostccr_reg;
64};
65
66struct ingenic_ost_clk {
67 struct clk_hw hw;
68 unsigned int idx;
69 struct ingenic_ost *ost;
70 const struct ingenic_ost_clk_info *info;
71};
72
73struct ingenic_ost {
74 void __iomem *base;
75 const struct ingenic_soc_info *soc_info;
76 struct clk *clk, *percpu_timer_clk, *global_timer_clk;
77 struct clock_event_device cevt;
78 struct clocksource cs;
79 char name[20];
80
81 struct clk_hw_onecell_data *clocks;
82};
83
84static struct ingenic_ost *ingenic_ost;
85
86static inline struct ingenic_ost_clk *to_ost_clk(struct clk_hw *hw)
87{
88 return container_of(hw, struct ingenic_ost_clk, hw);
89}
90
91static unsigned long ingenic_ost_percpu_timer_recalc_rate(struct clk_hw *hw,
92 unsigned long parent_rate)
93{
94 struct ingenic_ost_clk *ost_clk = to_ost_clk(hw);
95 const struct ingenic_ost_clk_info *info = ost_clk->info;
96 unsigned int prescale;
97
98 prescale = readl(addr: ost_clk->ost->base + info->ostccr_reg);
99
100 prescale = FIELD_GET(OSTCCR_PRESCALE1_MASK, prescale);
101
102 return parent_rate >> (prescale * 2);
103}
104
105static unsigned long ingenic_ost_global_timer_recalc_rate(struct clk_hw *hw,
106 unsigned long parent_rate)
107{
108 struct ingenic_ost_clk *ost_clk = to_ost_clk(hw);
109 const struct ingenic_ost_clk_info *info = ost_clk->info;
110 unsigned int prescale;
111
112 prescale = readl(addr: ost_clk->ost->base + info->ostccr_reg);
113
114 prescale = FIELD_GET(OSTCCR_PRESCALE2_MASK, prescale);
115
116 return parent_rate >> (prescale * 2);
117}
118
119static u8 ingenic_ost_get_prescale(unsigned long rate, unsigned long req_rate)
120{
121 u8 prescale;
122
123 for (prescale = 0; prescale < 2; prescale++)
124 if ((rate >> (prescale * 2)) <= req_rate)
125 return prescale;
126
127 return 2; /* /16 divider */
128}
129
130static long ingenic_ost_round_rate(struct clk_hw *hw, unsigned long req_rate,
131 unsigned long *parent_rate)
132{
133 unsigned long rate = *parent_rate;
134 u8 prescale;
135
136 if (req_rate > rate)
137 return rate;
138
139 prescale = ingenic_ost_get_prescale(rate, req_rate);
140
141 return rate >> (prescale * 2);
142}
143
144static int ingenic_ost_percpu_timer_set_rate(struct clk_hw *hw, unsigned long req_rate,
145 unsigned long parent_rate)
146{
147 struct ingenic_ost_clk *ost_clk = to_ost_clk(hw);
148 const struct ingenic_ost_clk_info *info = ost_clk->info;
149 u8 prescale = ingenic_ost_get_prescale(rate: parent_rate, req_rate);
150 int val;
151
152 val = readl(addr: ost_clk->ost->base + info->ostccr_reg);
153 val &= ~OSTCCR_PRESCALE1_MASK;
154 val |= FIELD_PREP(OSTCCR_PRESCALE1_MASK, prescale);
155 writel(val, addr: ost_clk->ost->base + info->ostccr_reg);
156
157 return 0;
158}
159
160static int ingenic_ost_global_timer_set_rate(struct clk_hw *hw, unsigned long req_rate,
161 unsigned long parent_rate)
162{
163 struct ingenic_ost_clk *ost_clk = to_ost_clk(hw);
164 const struct ingenic_ost_clk_info *info = ost_clk->info;
165 u8 prescale = ingenic_ost_get_prescale(rate: parent_rate, req_rate);
166 int val;
167
168 val = readl(addr: ost_clk->ost->base + info->ostccr_reg);
169 val &= ~OSTCCR_PRESCALE2_MASK;
170 val |= FIELD_PREP(OSTCCR_PRESCALE2_MASK, prescale);
171 writel(val, addr: ost_clk->ost->base + info->ostccr_reg);
172
173 return 0;
174}
175
176static const struct clk_ops ingenic_ost_percpu_timer_ops = {
177 .recalc_rate = ingenic_ost_percpu_timer_recalc_rate,
178 .round_rate = ingenic_ost_round_rate,
179 .set_rate = ingenic_ost_percpu_timer_set_rate,
180};
181
182static const struct clk_ops ingenic_ost_global_timer_ops = {
183 .recalc_rate = ingenic_ost_global_timer_recalc_rate,
184 .round_rate = ingenic_ost_round_rate,
185 .set_rate = ingenic_ost_global_timer_set_rate,
186};
187
188static const char * const ingenic_ost_clk_parents[] = { "ext" };
189
190static const struct ingenic_ost_clk_info x1000_ost_clk_info[] = {
191 [OST_CLK_PERCPU_TIMER] = {
192 .init_data = {
193 .name = "percpu timer",
194 .parent_names = ingenic_ost_clk_parents,
195 .num_parents = ARRAY_SIZE(ingenic_ost_clk_parents),
196 .ops = &ingenic_ost_percpu_timer_ops,
197 .flags = CLK_SET_RATE_UNGATE,
198 },
199 .ostccr_reg = OST_REG_OSTCCR,
200 },
201
202 [OST_CLK_GLOBAL_TIMER] = {
203 .init_data = {
204 .name = "global timer",
205 .parent_names = ingenic_ost_clk_parents,
206 .num_parents = ARRAY_SIZE(ingenic_ost_clk_parents),
207 .ops = &ingenic_ost_global_timer_ops,
208 .flags = CLK_SET_RATE_UNGATE,
209 },
210 .ostccr_reg = OST_REG_OSTCCR,
211 },
212};
213
214static u64 notrace ingenic_ost_global_timer_read_cntl(void)
215{
216 struct ingenic_ost *ost = ingenic_ost;
217 unsigned int count;
218
219 count = readl(addr: ost->base + OST_REG_OST2CNTL);
220
221 return count;
222}
223
224static u64 notrace ingenic_ost_clocksource_read(struct clocksource *cs)
225{
226 return ingenic_ost_global_timer_read_cntl();
227}
228
229static inline struct ingenic_ost *to_ingenic_ost(struct clock_event_device *evt)
230{
231 return container_of(evt, struct ingenic_ost, cevt);
232}
233
234static int ingenic_ost_cevt_set_state_shutdown(struct clock_event_device *evt)
235{
236 struct ingenic_ost *ost = to_ingenic_ost(evt);
237
238 writel(OSTECR_OST1ENC, addr: ost->base + OST_REG_OSTECR);
239
240 return 0;
241}
242
243static int ingenic_ost_cevt_set_next(unsigned long next,
244 struct clock_event_device *evt)
245{
246 struct ingenic_ost *ost = to_ingenic_ost(evt);
247
248 writel(val: (u32)~OSTFR_FFLAG, addr: ost->base + OST_REG_OSTFR);
249 writel(val: next, addr: ost->base + OST_REG_OST1DFR);
250 writel(OSTCR_OST1CLR, addr: ost->base + OST_REG_OSTCR);
251 writel(OSTESR_OST1ENS, addr: ost->base + OST_REG_OSTESR);
252 writel(val: (u32)~OSTMR_FMASK, addr: ost->base + OST_REG_OSTMR);
253
254 return 0;
255}
256
257static irqreturn_t ingenic_ost_cevt_cb(int irq, void *dev_id)
258{
259 struct clock_event_device *evt = dev_id;
260 struct ingenic_ost *ost = to_ingenic_ost(evt);
261
262 writel(OSTECR_OST1ENC, addr: ost->base + OST_REG_OSTECR);
263
264 if (evt->event_handler)
265 evt->event_handler(evt);
266
267 return IRQ_HANDLED;
268}
269
270static int __init ingenic_ost_register_clock(struct ingenic_ost *ost,
271 unsigned int idx, const struct ingenic_ost_clk_info *info,
272 struct clk_hw_onecell_data *clocks)
273{
274 struct ingenic_ost_clk *ost_clk;
275 int val, err;
276
277 ost_clk = kzalloc(sizeof(*ost_clk), GFP_KERNEL);
278 if (!ost_clk)
279 return -ENOMEM;
280
281 ost_clk->hw.init = &info->init_data;
282 ost_clk->idx = idx;
283 ost_clk->info = info;
284 ost_clk->ost = ost;
285
286 /* Reset clock divider */
287 val = readl(addr: ost->base + info->ostccr_reg);
288 val &= ~(OSTCCR_PRESCALE1_MASK | OSTCCR_PRESCALE2_MASK);
289 writel(val, addr: ost->base + info->ostccr_reg);
290
291 err = clk_hw_register(NULL, hw: &ost_clk->hw);
292 if (err) {
293 kfree(objp: ost_clk);
294 return err;
295 }
296
297 clocks->hws[idx] = &ost_clk->hw;
298
299 return 0;
300}
301
302static struct clk * __init ingenic_ost_get_clock(struct device_node *np, int id)
303{
304 struct of_phandle_args args;
305
306 args.np = np;
307 args.args_count = 1;
308 args.args[0] = id;
309
310 return of_clk_get_from_provider(clkspec: &args);
311}
312
313static int __init ingenic_ost_percpu_timer_init(struct device_node *np,
314 struct ingenic_ost *ost)
315{
316 unsigned int timer_virq, channel = OST_CLK_PERCPU_TIMER;
317 unsigned long rate;
318 int err;
319
320 ost->percpu_timer_clk = ingenic_ost_get_clock(np, id: channel);
321 if (IS_ERR(ptr: ost->percpu_timer_clk))
322 return PTR_ERR(ptr: ost->percpu_timer_clk);
323
324 err = clk_prepare_enable(clk: ost->percpu_timer_clk);
325 if (err)
326 goto err_clk_put;
327
328 rate = clk_get_rate(clk: ost->percpu_timer_clk);
329 if (!rate) {
330 err = -EINVAL;
331 goto err_clk_disable;
332 }
333
334 timer_virq = of_irq_get(dev: np, index: 0);
335 if (!timer_virq) {
336 err = -EINVAL;
337 goto err_clk_disable;
338 }
339
340 snprintf(buf: ost->name, size: sizeof(ost->name), fmt: "OST percpu timer");
341
342 err = request_irq(irq: timer_virq, handler: ingenic_ost_cevt_cb, IRQF_TIMER,
343 name: ost->name, dev: &ost->cevt);
344 if (err)
345 goto err_irq_dispose_mapping;
346
347 ost->cevt.cpumask = cpumask_of(smp_processor_id());
348 ost->cevt.features = CLOCK_EVT_FEAT_ONESHOT;
349 ost->cevt.name = ost->name;
350 ost->cevt.rating = 400;
351 ost->cevt.set_state_shutdown = ingenic_ost_cevt_set_state_shutdown;
352 ost->cevt.set_next_event = ingenic_ost_cevt_set_next;
353
354 clockevents_config_and_register(dev: &ost->cevt, freq: rate, min_delta: 4, max_delta: 0xffffffff);
355
356 return 0;
357
358err_irq_dispose_mapping:
359 irq_dispose_mapping(virq: timer_virq);
360err_clk_disable:
361 clk_disable_unprepare(clk: ost->percpu_timer_clk);
362err_clk_put:
363 clk_put(clk: ost->percpu_timer_clk);
364 return err;
365}
366
367static int __init ingenic_ost_global_timer_init(struct device_node *np,
368 struct ingenic_ost *ost)
369{
370 unsigned int channel = OST_CLK_GLOBAL_TIMER;
371 struct clocksource *cs = &ost->cs;
372 unsigned long rate;
373 int err;
374
375 ost->global_timer_clk = ingenic_ost_get_clock(np, id: channel);
376 if (IS_ERR(ptr: ost->global_timer_clk))
377 return PTR_ERR(ptr: ost->global_timer_clk);
378
379 err = clk_prepare_enable(clk: ost->global_timer_clk);
380 if (err)
381 goto err_clk_put;
382
383 rate = clk_get_rate(clk: ost->global_timer_clk);
384 if (!rate) {
385 err = -EINVAL;
386 goto err_clk_disable;
387 }
388
389 /* Clear counter CNT registers */
390 writel(OSTCR_OST2CLR, addr: ost->base + OST_REG_OSTCR);
391
392 /* Enable OST channel */
393 writel(OSTESR_OST2ENS, addr: ost->base + OST_REG_OSTESR);
394
395 cs->name = "ingenic-ost";
396 cs->rating = 400;
397 cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
398 cs->mask = CLOCKSOURCE_MASK(32);
399 cs->read = ingenic_ost_clocksource_read;
400
401 err = clocksource_register_hz(cs, hz: rate);
402 if (err)
403 goto err_clk_disable;
404
405 return 0;
406
407err_clk_disable:
408 clk_disable_unprepare(clk: ost->global_timer_clk);
409err_clk_put:
410 clk_put(clk: ost->global_timer_clk);
411 return err;
412}
413
414static const struct ingenic_soc_info x1000_soc_info = {
415 .num_channels = 2,
416};
417
418static const struct of_device_id __maybe_unused ingenic_ost_of_matches[] __initconst = {
419 { .compatible = "ingenic,x1000-ost", .data = &x1000_soc_info },
420 { /* sentinel */ }
421};
422
423static int __init ingenic_ost_probe(struct device_node *np)
424{
425 const struct of_device_id *id = of_match_node(matches: ingenic_ost_of_matches, node: np);
426 struct ingenic_ost *ost;
427 unsigned int i;
428 int ret;
429
430 ost = kzalloc(sizeof(*ost), GFP_KERNEL);
431 if (!ost)
432 return -ENOMEM;
433
434 ost->base = of_io_request_and_map(device: np, index: 0, name: of_node_full_name(np));
435 if (IS_ERR(ptr: ost->base)) {
436 pr_err("%s: Failed to map OST registers\n", __func__);
437 ret = PTR_ERR(ptr: ost->base);
438 goto err_free_ost;
439 }
440
441 ost->clk = of_clk_get_by_name(np, name: "ost");
442 if (IS_ERR(ptr: ost->clk)) {
443 ret = PTR_ERR(ptr: ost->clk);
444 pr_crit("%s: Cannot get OST clock\n", __func__);
445 goto err_free_ost;
446 }
447
448 ret = clk_prepare_enable(clk: ost->clk);
449 if (ret) {
450 pr_crit("%s: Unable to enable OST clock\n", __func__);
451 goto err_put_clk;
452 }
453
454 ost->soc_info = id->data;
455
456 ost->clocks = kzalloc(struct_size(ost->clocks, hws, ost->soc_info->num_channels),
457 GFP_KERNEL);
458 if (!ost->clocks) {
459 ret = -ENOMEM;
460 goto err_clk_disable;
461 }
462
463 ost->clocks->num = ost->soc_info->num_channels;
464
465 for (i = 0; i < ost->clocks->num; i++) {
466 ret = ingenic_ost_register_clock(ost, idx: i, info: &x1000_ost_clk_info[i], clocks: ost->clocks);
467 if (ret) {
468 pr_crit("%s: Cannot register clock %d\n", __func__, i);
469 goto err_unregister_ost_clocks;
470 }
471 }
472
473 ret = of_clk_add_hw_provider(np, get: of_clk_hw_onecell_get, data: ost->clocks);
474 if (ret) {
475 pr_crit("%s: Cannot add OF clock provider\n", __func__);
476 goto err_unregister_ost_clocks;
477 }
478
479 ingenic_ost = ost;
480
481 return 0;
482
483err_unregister_ost_clocks:
484 for (i = 0; i < ost->clocks->num; i++)
485 if (ost->clocks->hws[i])
486 clk_hw_unregister(hw: ost->clocks->hws[i]);
487 kfree(objp: ost->clocks);
488err_clk_disable:
489 clk_disable_unprepare(clk: ost->clk);
490err_put_clk:
491 clk_put(clk: ost->clk);
492err_free_ost:
493 kfree(objp: ost);
494 return ret;
495}
496
497static int __init ingenic_ost_init(struct device_node *np)
498{
499 struct ingenic_ost *ost;
500 unsigned long rate;
501 int ret;
502
503 ret = ingenic_ost_probe(np);
504 if (ret) {
505 pr_crit("%s: Failed to initialize OST clocks: %d\n", __func__, ret);
506 return ret;
507 }
508
509 of_node_clear_flag(n: np, OF_POPULATED);
510
511 ost = ingenic_ost;
512 if (IS_ERR(ptr: ost))
513 return PTR_ERR(ptr: ost);
514
515 ret = ingenic_ost_global_timer_init(np, ost);
516 if (ret) {
517 pr_crit("%s: Unable to init global timer: %x\n", __func__, ret);
518 goto err_free_ingenic_ost;
519 }
520
521 ret = ingenic_ost_percpu_timer_init(np, ost);
522 if (ret)
523 goto err_ost_global_timer_cleanup;
524
525 /* Register the sched_clock at the end as there's no way to undo it */
526 rate = clk_get_rate(clk: ost->global_timer_clk);
527 sched_clock_register(read: ingenic_ost_global_timer_read_cntl, bits: 32, rate);
528
529 return 0;
530
531err_ost_global_timer_cleanup:
532 clocksource_unregister(&ost->cs);
533 clk_disable_unprepare(clk: ost->global_timer_clk);
534 clk_put(clk: ost->global_timer_clk);
535err_free_ingenic_ost:
536 kfree(objp: ost);
537 return ret;
538}
539
540TIMER_OF_DECLARE(x1000_ost, "ingenic,x1000-ost", ingenic_ost_init);
541

source code of linux/drivers/clocksource/ingenic-sysost.c