Loading...
Note: File does not exist in v3.15.
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright © 2014-2023 Broadcom
4 */
5
6#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7
8#include <linux/clk.h>
9#include <linux/device.h>
10#include <linux/err.h>
11#include <linux/init.h>
12#include <linux/interrupt.h>
13#include <linux/io.h>
14#include <linux/irqreturn.h>
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/of.h>
18#include <linux/platform_device.h>
19#include <linux/pm.h>
20#include <linux/reboot.h>
21#include <linux/rtc.h>
22#include <linux/stat.h>
23#include <linux/suspend.h>
24
25struct brcmstb_waketmr {
26 struct rtc_device *rtc;
27 struct device *dev;
28 void __iomem *base;
29 unsigned int wake_irq;
30 unsigned int alarm_irq;
31 struct notifier_block reboot_notifier;
32 struct clk *clk;
33 u32 rate;
34 unsigned long rtc_alarm;
35 bool alarm_en;
36 bool alarm_expired;
37};
38
39#define BRCMSTB_WKTMR_EVENT 0x00
40#define WKTMR_ALARM_EVENT BIT(0)
41#define BRCMSTB_WKTMR_COUNTER 0x04
42#define BRCMSTB_WKTMR_ALARM 0x08
43#define BRCMSTB_WKTMR_PRESCALER 0x0C
44#define BRCMSTB_WKTMR_PRESCALER_VAL 0x10
45
46#define BRCMSTB_WKTMR_DEFAULT_FREQ 27000000
47
48static inline bool brcmstb_waketmr_is_pending(struct brcmstb_waketmr *timer)
49{
50 u32 reg;
51
52 reg = readl_relaxed(timer->base + BRCMSTB_WKTMR_EVENT);
53 return !!(reg & WKTMR_ALARM_EVENT);
54}
55
56static inline void brcmstb_waketmr_clear_alarm(struct brcmstb_waketmr *timer)
57{
58 u32 reg;
59
60 if (timer->alarm_en && timer->alarm_irq)
61 disable_irq(timer->alarm_irq);
62 timer->alarm_en = false;
63 reg = readl_relaxed(timer->base + BRCMSTB_WKTMR_COUNTER);
64 writel_relaxed(reg - 1, timer->base + BRCMSTB_WKTMR_ALARM);
65 writel_relaxed(WKTMR_ALARM_EVENT, timer->base + BRCMSTB_WKTMR_EVENT);
66 (void)readl_relaxed(timer->base + BRCMSTB_WKTMR_EVENT);
67 if (timer->alarm_expired) {
68 timer->alarm_expired = false;
69 /* maintain call balance */
70 enable_irq(timer->alarm_irq);
71 }
72}
73
74static void brcmstb_waketmr_set_alarm(struct brcmstb_waketmr *timer,
75 unsigned int secs)
76{
77 unsigned int now;
78
79 brcmstb_waketmr_clear_alarm(timer);
80
81 /* Make sure we are actually counting in seconds */
82 writel_relaxed(timer->rate, timer->base + BRCMSTB_WKTMR_PRESCALER);
83
84 writel_relaxed(secs, timer->base + BRCMSTB_WKTMR_ALARM);
85 now = readl_relaxed(timer->base + BRCMSTB_WKTMR_COUNTER);
86
87 while ((int)(secs - now) <= 0 &&
88 !brcmstb_waketmr_is_pending(timer)) {
89 secs = now + 1;
90 writel_relaxed(secs, timer->base + BRCMSTB_WKTMR_ALARM);
91 now = readl_relaxed(timer->base + BRCMSTB_WKTMR_COUNTER);
92 }
93}
94
95static irqreturn_t brcmstb_waketmr_irq(int irq, void *data)
96{
97 struct brcmstb_waketmr *timer = data;
98
99 if (!timer->alarm_irq)
100 pm_wakeup_event(timer->dev, 0);
101 return IRQ_HANDLED;
102}
103
104static irqreturn_t brcmstb_alarm_irq(int irq, void *data)
105{
106 struct brcmstb_waketmr *timer = data;
107
108 /* Ignore spurious interrupts */
109 if (!brcmstb_waketmr_is_pending(timer))
110 return IRQ_HANDLED;
111
112 if (timer->alarm_en) {
113 if (device_may_wakeup(timer->dev)) {
114 disable_irq_nosync(irq);
115 timer->alarm_expired = true;
116 } else {
117 writel_relaxed(WKTMR_ALARM_EVENT,
118 timer->base + BRCMSTB_WKTMR_EVENT);
119 }
120 rtc_update_irq(timer->rtc, 1, RTC_IRQF | RTC_AF);
121 } else {
122 writel_relaxed(WKTMR_ALARM_EVENT,
123 timer->base + BRCMSTB_WKTMR_EVENT);
124 }
125
126 return IRQ_HANDLED;
127}
128
129struct wktmr_time {
130 u32 sec;
131 u32 pre;
132};
133
134static void wktmr_read(struct brcmstb_waketmr *timer,
135 struct wktmr_time *t)
136{
137 u32 tmp;
138
139 do {
140 t->sec = readl_relaxed(timer->base + BRCMSTB_WKTMR_COUNTER);
141 tmp = readl_relaxed(timer->base + BRCMSTB_WKTMR_PRESCALER_VAL);
142 } while (tmp >= timer->rate);
143
144 t->pre = timer->rate - tmp;
145}
146
147static int brcmstb_waketmr_prepare_suspend(struct brcmstb_waketmr *timer)
148{
149 struct device *dev = timer->dev;
150 int ret;
151
152 if (device_may_wakeup(dev)) {
153 ret = enable_irq_wake(timer->wake_irq);
154 if (ret) {
155 dev_err(dev, "failed to enable wake-up interrupt\n");
156 return ret;
157 }
158 if (timer->alarm_en && timer->alarm_irq) {
159 ret = enable_irq_wake(timer->alarm_irq);
160 if (ret) {
161 dev_err(dev, "failed to enable rtc interrupt\n");
162 disable_irq_wake(timer->wake_irq);
163 return ret;
164 }
165 }
166 }
167
168 return 0;
169}
170
171/* If enabled as a wakeup-source, arm the timer when powering off */
172static int brcmstb_waketmr_reboot(struct notifier_block *nb,
173 unsigned long action, void *data)
174{
175 struct brcmstb_waketmr *timer;
176
177 timer = container_of(nb, struct brcmstb_waketmr, reboot_notifier);
178
179 /* Set timer for cold boot */
180 if (action == SYS_POWER_OFF)
181 brcmstb_waketmr_prepare_suspend(timer);
182
183 return NOTIFY_DONE;
184}
185
186static int brcmstb_waketmr_gettime(struct device *dev,
187 struct rtc_time *tm)
188{
189 struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
190 struct wktmr_time now;
191
192 wktmr_read(timer, &now);
193
194 rtc_time64_to_tm(now.sec, tm);
195
196 return 0;
197}
198
199static int brcmstb_waketmr_settime(struct device *dev,
200 struct rtc_time *tm)
201{
202 struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
203 time64_t sec;
204
205 sec = rtc_tm_to_time64(tm);
206
207 writel_relaxed(sec, timer->base + BRCMSTB_WKTMR_COUNTER);
208
209 return 0;
210}
211
212static int brcmstb_waketmr_getalarm(struct device *dev,
213 struct rtc_wkalrm *alarm)
214{
215 struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
216
217 alarm->enabled = timer->alarm_en;
218 rtc_time64_to_tm(timer->rtc_alarm, &alarm->time);
219
220 alarm->pending = brcmstb_waketmr_is_pending(timer);
221
222 return 0;
223}
224
225static int brcmstb_waketmr_alarm_enable(struct device *dev,
226 unsigned int enabled)
227{
228 struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
229
230 if (enabled && !timer->alarm_en) {
231 if ((int)(readl_relaxed(timer->base + BRCMSTB_WKTMR_COUNTER) -
232 readl_relaxed(timer->base + BRCMSTB_WKTMR_ALARM)) >= 0 &&
233 !brcmstb_waketmr_is_pending(timer))
234 return -EINVAL;
235 timer->alarm_en = true;
236 if (timer->alarm_irq) {
237 if (timer->alarm_expired) {
238 timer->alarm_expired = false;
239 /* maintain call balance */
240 enable_irq(timer->alarm_irq);
241 }
242 enable_irq(timer->alarm_irq);
243 }
244 } else if (!enabled && timer->alarm_en) {
245 if (timer->alarm_irq)
246 disable_irq(timer->alarm_irq);
247 timer->alarm_en = false;
248 }
249
250 return 0;
251}
252
253static int brcmstb_waketmr_setalarm(struct device *dev,
254 struct rtc_wkalrm *alarm)
255{
256 struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
257
258 timer->rtc_alarm = rtc_tm_to_time64(&alarm->time);
259
260 brcmstb_waketmr_set_alarm(timer, timer->rtc_alarm);
261
262 return brcmstb_waketmr_alarm_enable(dev, alarm->enabled);
263}
264
265static const struct rtc_class_ops brcmstb_waketmr_ops = {
266 .read_time = brcmstb_waketmr_gettime,
267 .set_time = brcmstb_waketmr_settime,
268 .read_alarm = brcmstb_waketmr_getalarm,
269 .set_alarm = brcmstb_waketmr_setalarm,
270 .alarm_irq_enable = brcmstb_waketmr_alarm_enable,
271};
272
273static int brcmstb_waketmr_probe(struct platform_device *pdev)
274{
275 struct device *dev = &pdev->dev;
276 struct brcmstb_waketmr *timer;
277 int ret;
278
279 timer = devm_kzalloc(dev, sizeof(*timer), GFP_KERNEL);
280 if (!timer)
281 return -ENOMEM;
282
283 platform_set_drvdata(pdev, timer);
284 timer->dev = dev;
285
286 timer->base = devm_platform_ioremap_resource(pdev, 0);
287 if (IS_ERR(timer->base))
288 return PTR_ERR(timer->base);
289
290 timer->rtc = devm_rtc_allocate_device(dev);
291 if (IS_ERR(timer->rtc))
292 return PTR_ERR(timer->rtc);
293
294 /*
295 * Set wakeup capability before requesting wakeup interrupt, so we can
296 * process boot-time "wakeups" (e.g., from S5 soft-off)
297 */
298 device_init_wakeup(dev, true);
299
300 ret = platform_get_irq(pdev, 0);
301 if (ret < 0)
302 return -ENODEV;
303 timer->wake_irq = (unsigned int)ret;
304
305 timer->clk = devm_clk_get(dev, NULL);
306 if (!IS_ERR(timer->clk)) {
307 ret = clk_prepare_enable(timer->clk);
308 if (ret)
309 return ret;
310 timer->rate = clk_get_rate(timer->clk);
311 if (!timer->rate)
312 timer->rate = BRCMSTB_WKTMR_DEFAULT_FREQ;
313 } else {
314 timer->rate = BRCMSTB_WKTMR_DEFAULT_FREQ;
315 timer->clk = NULL;
316 }
317
318 ret = devm_request_irq(dev, timer->wake_irq, brcmstb_waketmr_irq, 0,
319 "brcmstb-waketimer", timer);
320 if (ret < 0)
321 goto err_clk;
322
323 brcmstb_waketmr_clear_alarm(timer);
324
325 /* Attempt to initialize non-wake irq */
326 ret = platform_get_irq(pdev, 1);
327 if (ret > 0) {
328 timer->alarm_irq = (unsigned int)ret;
329 ret = devm_request_irq(dev, timer->alarm_irq, brcmstb_alarm_irq,
330 IRQF_NO_AUTOEN, "brcmstb-waketimer-rtc",
331 timer);
332 if (ret < 0)
333 timer->alarm_irq = 0;
334 }
335
336 timer->reboot_notifier.notifier_call = brcmstb_waketmr_reboot;
337 register_reboot_notifier(&timer->reboot_notifier);
338
339 timer->rtc->ops = &brcmstb_waketmr_ops;
340 timer->rtc->range_max = U32_MAX;
341
342 ret = devm_rtc_register_device(timer->rtc);
343 if (ret)
344 goto err_notifier;
345
346 return 0;
347
348err_notifier:
349 unregister_reboot_notifier(&timer->reboot_notifier);
350
351err_clk:
352 clk_disable_unprepare(timer->clk);
353
354 return ret;
355}
356
357static void brcmstb_waketmr_remove(struct platform_device *pdev)
358{
359 struct brcmstb_waketmr *timer = dev_get_drvdata(&pdev->dev);
360
361 unregister_reboot_notifier(&timer->reboot_notifier);
362 clk_disable_unprepare(timer->clk);
363}
364
365#ifdef CONFIG_PM_SLEEP
366static int brcmstb_waketmr_suspend(struct device *dev)
367{
368 struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
369
370 return brcmstb_waketmr_prepare_suspend(timer);
371}
372
373static int brcmstb_waketmr_suspend_noirq(struct device *dev)
374{
375 struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
376
377 /* Catch any alarms occurring prior to noirq */
378 if (timer->alarm_expired && device_may_wakeup(dev))
379 return -EBUSY;
380
381 return 0;
382}
383
384static int brcmstb_waketmr_resume(struct device *dev)
385{
386 struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
387 int ret;
388
389 if (!device_may_wakeup(dev))
390 return 0;
391
392 ret = disable_irq_wake(timer->wake_irq);
393 if (timer->alarm_en && timer->alarm_irq)
394 disable_irq_wake(timer->alarm_irq);
395
396 brcmstb_waketmr_clear_alarm(timer);
397
398 return ret;
399}
400#else
401#define brcmstb_waketmr_suspend NULL
402#define brcmstb_waketmr_suspend_noirq NULL
403#define brcmstb_waketmr_resume NULL
404#endif /* CONFIG_PM_SLEEP */
405
406static const struct dev_pm_ops brcmstb_waketmr_pm_ops = {
407 .suspend = brcmstb_waketmr_suspend,
408 .suspend_noirq = brcmstb_waketmr_suspend_noirq,
409 .resume = brcmstb_waketmr_resume,
410};
411
412static const __maybe_unused struct of_device_id brcmstb_waketmr_of_match[] = {
413 { .compatible = "brcm,brcmstb-waketimer" },
414 { /* sentinel */ },
415};
416
417static struct platform_driver brcmstb_waketmr_driver = {
418 .probe = brcmstb_waketmr_probe,
419 .remove = brcmstb_waketmr_remove,
420 .driver = {
421 .name = "brcmstb-waketimer",
422 .pm = &brcmstb_waketmr_pm_ops,
423 .of_match_table = of_match_ptr(brcmstb_waketmr_of_match),
424 }
425};
426module_platform_driver(brcmstb_waketmr_driver);
427
428MODULE_LICENSE("GPL v2");
429MODULE_AUTHOR("Brian Norris");
430MODULE_AUTHOR("Markus Mayer");
431MODULE_AUTHOR("Doug Berger");
432MODULE_DESCRIPTION("Wake-up timer driver for STB chips");