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1802d0be | 1 | // SPDX-License-Identifier: GPL-2.0-only |
c4f07ece BN |
2 | /* |
3 | * Copyright © 2014-2017 Broadcom | |
c4f07ece BN |
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/pm_wakeup.h> | |
21 | #include <linux/reboot.h> | |
22 | #include <linux/rtc.h> | |
23 | #include <linux/stat.h> | |
24 | #include <linux/suspend.h> | |
25 | ||
26 | struct brcmstb_waketmr { | |
27 | struct rtc_device *rtc; | |
28 | struct device *dev; | |
29 | void __iomem *base; | |
30 | int irq; | |
31 | struct notifier_block reboot_notifier; | |
32 | struct clk *clk; | |
33 | u32 rate; | |
34 | }; | |
35 | ||
36 | #define BRCMSTB_WKTMR_EVENT 0x00 | |
37 | #define BRCMSTB_WKTMR_COUNTER 0x04 | |
38 | #define BRCMSTB_WKTMR_ALARM 0x08 | |
39 | #define BRCMSTB_WKTMR_PRESCALER 0x0C | |
40 | #define BRCMSTB_WKTMR_PRESCALER_VAL 0x10 | |
41 | ||
42 | #define BRCMSTB_WKTMR_DEFAULT_FREQ 27000000 | |
43 | ||
44 | static inline void brcmstb_waketmr_clear_alarm(struct brcmstb_waketmr *timer) | |
45 | { | |
46 | writel_relaxed(1, timer->base + BRCMSTB_WKTMR_EVENT); | |
47 | (void)readl_relaxed(timer->base + BRCMSTB_WKTMR_EVENT); | |
48 | } | |
49 | ||
50 | static void brcmstb_waketmr_set_alarm(struct brcmstb_waketmr *timer, | |
51 | unsigned int secs) | |
52 | { | |
53 | brcmstb_waketmr_clear_alarm(timer); | |
54 | ||
58d3d5e7 JC |
55 | /* Make sure we are actually counting in seconds */ |
56 | writel_relaxed(timer->rate, timer->base + BRCMSTB_WKTMR_PRESCALER); | |
57 | ||
c4f07ece BN |
58 | writel_relaxed(secs + 1, timer->base + BRCMSTB_WKTMR_ALARM); |
59 | } | |
60 | ||
61 | static irqreturn_t brcmstb_waketmr_irq(int irq, void *data) | |
62 | { | |
63 | struct brcmstb_waketmr *timer = data; | |
64 | ||
65 | pm_wakeup_event(timer->dev, 0); | |
66 | ||
67 | return IRQ_HANDLED; | |
68 | } | |
69 | ||
70 | struct wktmr_time { | |
71 | u32 sec; | |
72 | u32 pre; | |
73 | }; | |
74 | ||
75 | static void wktmr_read(struct brcmstb_waketmr *timer, | |
76 | struct wktmr_time *t) | |
77 | { | |
78 | u32 tmp; | |
79 | ||
80 | do { | |
81 | t->sec = readl_relaxed(timer->base + BRCMSTB_WKTMR_COUNTER); | |
82 | tmp = readl_relaxed(timer->base + BRCMSTB_WKTMR_PRESCALER_VAL); | |
83 | } while (tmp >= timer->rate); | |
84 | ||
85 | t->pre = timer->rate - tmp; | |
86 | } | |
87 | ||
88 | static int brcmstb_waketmr_prepare_suspend(struct brcmstb_waketmr *timer) | |
89 | { | |
90 | struct device *dev = timer->dev; | |
91 | int ret = 0; | |
92 | ||
93 | if (device_may_wakeup(dev)) { | |
94 | ret = enable_irq_wake(timer->irq); | |
95 | if (ret) { | |
96 | dev_err(dev, "failed to enable wake-up interrupt\n"); | |
97 | return ret; | |
98 | } | |
99 | } | |
100 | ||
101 | return ret; | |
102 | } | |
103 | ||
104 | /* If enabled as a wakeup-source, arm the timer when powering off */ | |
105 | static int brcmstb_waketmr_reboot(struct notifier_block *nb, | |
106 | unsigned long action, void *data) | |
107 | { | |
108 | struct brcmstb_waketmr *timer; | |
109 | ||
110 | timer = container_of(nb, struct brcmstb_waketmr, reboot_notifier); | |
111 | ||
112 | /* Set timer for cold boot */ | |
113 | if (action == SYS_POWER_OFF) | |
114 | brcmstb_waketmr_prepare_suspend(timer); | |
115 | ||
116 | return NOTIFY_DONE; | |
117 | } | |
118 | ||
119 | static int brcmstb_waketmr_gettime(struct device *dev, | |
120 | struct rtc_time *tm) | |
121 | { | |
122 | struct brcmstb_waketmr *timer = dev_get_drvdata(dev); | |
123 | struct wktmr_time now; | |
124 | ||
125 | wktmr_read(timer, &now); | |
126 | ||
9a8f2d12 | 127 | rtc_time64_to_tm(now.sec, tm); |
c4f07ece BN |
128 | |
129 | return 0; | |
130 | } | |
131 | ||
132 | static int brcmstb_waketmr_settime(struct device *dev, | |
133 | struct rtc_time *tm) | |
134 | { | |
135 | struct brcmstb_waketmr *timer = dev_get_drvdata(dev); | |
136 | time64_t sec; | |
137 | ||
138 | sec = rtc_tm_to_time64(tm); | |
139 | ||
c4f07ece BN |
140 | writel_relaxed(sec, timer->base + BRCMSTB_WKTMR_COUNTER); |
141 | ||
142 | return 0; | |
143 | } | |
144 | ||
145 | static int brcmstb_waketmr_getalarm(struct device *dev, | |
146 | struct rtc_wkalrm *alarm) | |
147 | { | |
148 | struct brcmstb_waketmr *timer = dev_get_drvdata(dev); | |
149 | time64_t sec; | |
150 | u32 reg; | |
151 | ||
152 | sec = readl_relaxed(timer->base + BRCMSTB_WKTMR_ALARM); | |
153 | if (sec != 0) { | |
154 | /* Alarm is enabled */ | |
155 | alarm->enabled = 1; | |
156 | rtc_time64_to_tm(sec, &alarm->time); | |
157 | } | |
158 | ||
159 | reg = readl_relaxed(timer->base + BRCMSTB_WKTMR_EVENT); | |
160 | alarm->pending = !!(reg & 1); | |
161 | ||
162 | return 0; | |
163 | } | |
164 | ||
165 | static int brcmstb_waketmr_setalarm(struct device *dev, | |
166 | struct rtc_wkalrm *alarm) | |
167 | { | |
168 | struct brcmstb_waketmr *timer = dev_get_drvdata(dev); | |
169 | time64_t sec; | |
170 | ||
171 | if (alarm->enabled) | |
172 | sec = rtc_tm_to_time64(&alarm->time); | |
173 | else | |
174 | sec = 0; | |
175 | ||
c4f07ece BN |
176 | brcmstb_waketmr_set_alarm(timer, sec); |
177 | ||
178 | return 0; | |
179 | } | |
180 | ||
181 | /* | |
182 | * Does not do much but keep the RTC class happy. We always support | |
183 | * alarms. | |
184 | */ | |
185 | static int brcmstb_waketmr_alarm_enable(struct device *dev, | |
186 | unsigned int enabled) | |
187 | { | |
188 | return 0; | |
189 | } | |
190 | ||
191 | static const struct rtc_class_ops brcmstb_waketmr_ops = { | |
192 | .read_time = brcmstb_waketmr_gettime, | |
193 | .set_time = brcmstb_waketmr_settime, | |
194 | .read_alarm = brcmstb_waketmr_getalarm, | |
195 | .set_alarm = brcmstb_waketmr_setalarm, | |
196 | .alarm_irq_enable = brcmstb_waketmr_alarm_enable, | |
197 | }; | |
198 | ||
199 | static int brcmstb_waketmr_probe(struct platform_device *pdev) | |
200 | { | |
201 | struct device *dev = &pdev->dev; | |
202 | struct brcmstb_waketmr *timer; | |
203 | struct resource *res; | |
204 | int ret; | |
205 | ||
206 | timer = devm_kzalloc(dev, sizeof(*timer), GFP_KERNEL); | |
207 | if (!timer) | |
208 | return -ENOMEM; | |
209 | ||
210 | platform_set_drvdata(pdev, timer); | |
211 | timer->dev = dev; | |
212 | ||
213 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
214 | timer->base = devm_ioremap_resource(dev, res); | |
215 | if (IS_ERR(timer->base)) | |
216 | return PTR_ERR(timer->base); | |
217 | ||
2abf286a AB |
218 | timer->rtc = devm_rtc_allocate_device(dev); |
219 | if (IS_ERR(timer->rtc)) | |
220 | return PTR_ERR(timer->rtc); | |
221 | ||
c4f07ece BN |
222 | /* |
223 | * Set wakeup capability before requesting wakeup interrupt, so we can | |
224 | * process boot-time "wakeups" (e.g., from S5 soft-off) | |
225 | */ | |
226 | device_set_wakeup_capable(dev, true); | |
227 | device_wakeup_enable(dev); | |
228 | ||
229 | timer->irq = platform_get_irq(pdev, 0); | |
230 | if (timer->irq < 0) | |
231 | return -ENODEV; | |
232 | ||
233 | timer->clk = devm_clk_get(dev, NULL); | |
234 | if (!IS_ERR(timer->clk)) { | |
235 | ret = clk_prepare_enable(timer->clk); | |
236 | if (ret) | |
237 | return ret; | |
238 | timer->rate = clk_get_rate(timer->clk); | |
239 | if (!timer->rate) | |
240 | timer->rate = BRCMSTB_WKTMR_DEFAULT_FREQ; | |
241 | } else { | |
242 | timer->rate = BRCMSTB_WKTMR_DEFAULT_FREQ; | |
243 | timer->clk = NULL; | |
244 | } | |
245 | ||
246 | ret = devm_request_irq(dev, timer->irq, brcmstb_waketmr_irq, 0, | |
247 | "brcmstb-waketimer", timer); | |
248 | if (ret < 0) | |
f2eef045 | 249 | goto err_clk; |
c4f07ece BN |
250 | |
251 | timer->reboot_notifier.notifier_call = brcmstb_waketmr_reboot; | |
252 | register_reboot_notifier(&timer->reboot_notifier); | |
253 | ||
2abf286a | 254 | timer->rtc->ops = &brcmstb_waketmr_ops; |
ded67666 | 255 | timer->rtc->range_max = U32_MAX; |
2abf286a AB |
256 | |
257 | ret = rtc_register_device(timer->rtc); | |
258 | if (ret) { | |
c4f07ece | 259 | dev_err(dev, "unable to register device\n"); |
f2eef045 | 260 | goto err_notifier; |
c4f07ece BN |
261 | } |
262 | ||
263 | dev_info(dev, "registered, with irq %d\n", timer->irq); | |
264 | ||
f2eef045 AK |
265 | return 0; |
266 | ||
267 | err_notifier: | |
268 | unregister_reboot_notifier(&timer->reboot_notifier); | |
269 | ||
270 | err_clk: | |
271 | if (timer->clk) | |
272 | clk_disable_unprepare(timer->clk); | |
273 | ||
c4f07ece BN |
274 | return ret; |
275 | } | |
276 | ||
277 | static int brcmstb_waketmr_remove(struct platform_device *pdev) | |
278 | { | |
279 | struct brcmstb_waketmr *timer = dev_get_drvdata(&pdev->dev); | |
280 | ||
281 | unregister_reboot_notifier(&timer->reboot_notifier); | |
c4f07ece BN |
282 | |
283 | return 0; | |
284 | } | |
285 | ||
286 | #ifdef CONFIG_PM_SLEEP | |
287 | static int brcmstb_waketmr_suspend(struct device *dev) | |
288 | { | |
289 | struct brcmstb_waketmr *timer = dev_get_drvdata(dev); | |
290 | ||
291 | return brcmstb_waketmr_prepare_suspend(timer); | |
292 | } | |
293 | ||
294 | static int brcmstb_waketmr_resume(struct device *dev) | |
295 | { | |
296 | struct brcmstb_waketmr *timer = dev_get_drvdata(dev); | |
297 | int ret; | |
298 | ||
299 | if (!device_may_wakeup(dev)) | |
300 | return 0; | |
301 | ||
302 | ret = disable_irq_wake(timer->irq); | |
303 | ||
304 | brcmstb_waketmr_clear_alarm(timer); | |
305 | ||
306 | return ret; | |
307 | } | |
308 | #endif /* CONFIG_PM_SLEEP */ | |
309 | ||
310 | static SIMPLE_DEV_PM_OPS(brcmstb_waketmr_pm_ops, | |
311 | brcmstb_waketmr_suspend, brcmstb_waketmr_resume); | |
312 | ||
313 | static const struct of_device_id brcmstb_waketmr_of_match[] = { | |
314 | { .compatible = "brcm,brcmstb-waketimer" }, | |
315 | { /* sentinel */ }, | |
316 | }; | |
317 | ||
318 | static struct platform_driver brcmstb_waketmr_driver = { | |
319 | .probe = brcmstb_waketmr_probe, | |
320 | .remove = brcmstb_waketmr_remove, | |
321 | .driver = { | |
322 | .name = "brcmstb-waketimer", | |
323 | .pm = &brcmstb_waketmr_pm_ops, | |
324 | .of_match_table = of_match_ptr(brcmstb_waketmr_of_match), | |
325 | } | |
326 | }; | |
327 | module_platform_driver(brcmstb_waketmr_driver); | |
328 | ||
329 | MODULE_LICENSE("GPL v2"); | |
330 | MODULE_AUTHOR("Brian Norris"); | |
331 | MODULE_AUTHOR("Markus Mayer"); | |
332 | MODULE_DESCRIPTION("Wake-up timer driver for STB chips"); |