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c4f07ece BN |
1 | /* |
2 | * Copyright © 2014-2017 Broadcom | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | * GNU General Public License for more details. | |
12 | */ | |
13 | ||
14 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
15 | ||
16 | #include <linux/clk.h> | |
17 | #include <linux/device.h> | |
18 | #include <linux/err.h> | |
19 | #include <linux/init.h> | |
20 | #include <linux/interrupt.h> | |
21 | #include <linux/io.h> | |
22 | #include <linux/irqreturn.h> | |
23 | #include <linux/kernel.h> | |
24 | #include <linux/module.h> | |
25 | #include <linux/of.h> | |
26 | #include <linux/platform_device.h> | |
27 | #include <linux/pm.h> | |
28 | #include <linux/pm_wakeup.h> | |
29 | #include <linux/reboot.h> | |
30 | #include <linux/rtc.h> | |
31 | #include <linux/stat.h> | |
32 | #include <linux/suspend.h> | |
33 | ||
34 | struct brcmstb_waketmr { | |
35 | struct rtc_device *rtc; | |
36 | struct device *dev; | |
37 | void __iomem *base; | |
38 | int irq; | |
39 | struct notifier_block reboot_notifier; | |
40 | struct clk *clk; | |
41 | u32 rate; | |
42 | }; | |
43 | ||
44 | #define BRCMSTB_WKTMR_EVENT 0x00 | |
45 | #define BRCMSTB_WKTMR_COUNTER 0x04 | |
46 | #define BRCMSTB_WKTMR_ALARM 0x08 | |
47 | #define BRCMSTB_WKTMR_PRESCALER 0x0C | |
48 | #define BRCMSTB_WKTMR_PRESCALER_VAL 0x10 | |
49 | ||
50 | #define BRCMSTB_WKTMR_DEFAULT_FREQ 27000000 | |
51 | ||
52 | static inline void brcmstb_waketmr_clear_alarm(struct brcmstb_waketmr *timer) | |
53 | { | |
54 | writel_relaxed(1, timer->base + BRCMSTB_WKTMR_EVENT); | |
55 | (void)readl_relaxed(timer->base + BRCMSTB_WKTMR_EVENT); | |
56 | } | |
57 | ||
58 | static void brcmstb_waketmr_set_alarm(struct brcmstb_waketmr *timer, | |
59 | unsigned int secs) | |
60 | { | |
61 | brcmstb_waketmr_clear_alarm(timer); | |
62 | ||
58d3d5e7 JC |
63 | /* Make sure we are actually counting in seconds */ |
64 | writel_relaxed(timer->rate, timer->base + BRCMSTB_WKTMR_PRESCALER); | |
65 | ||
c4f07ece BN |
66 | writel_relaxed(secs + 1, timer->base + BRCMSTB_WKTMR_ALARM); |
67 | } | |
68 | ||
69 | static irqreturn_t brcmstb_waketmr_irq(int irq, void *data) | |
70 | { | |
71 | struct brcmstb_waketmr *timer = data; | |
72 | ||
73 | pm_wakeup_event(timer->dev, 0); | |
74 | ||
75 | return IRQ_HANDLED; | |
76 | } | |
77 | ||
78 | struct wktmr_time { | |
79 | u32 sec; | |
80 | u32 pre; | |
81 | }; | |
82 | ||
83 | static void wktmr_read(struct brcmstb_waketmr *timer, | |
84 | struct wktmr_time *t) | |
85 | { | |
86 | u32 tmp; | |
87 | ||
88 | do { | |
89 | t->sec = readl_relaxed(timer->base + BRCMSTB_WKTMR_COUNTER); | |
90 | tmp = readl_relaxed(timer->base + BRCMSTB_WKTMR_PRESCALER_VAL); | |
91 | } while (tmp >= timer->rate); | |
92 | ||
93 | t->pre = timer->rate - tmp; | |
94 | } | |
95 | ||
96 | static int brcmstb_waketmr_prepare_suspend(struct brcmstb_waketmr *timer) | |
97 | { | |
98 | struct device *dev = timer->dev; | |
99 | int ret = 0; | |
100 | ||
101 | if (device_may_wakeup(dev)) { | |
102 | ret = enable_irq_wake(timer->irq); | |
103 | if (ret) { | |
104 | dev_err(dev, "failed to enable wake-up interrupt\n"); | |
105 | return ret; | |
106 | } | |
107 | } | |
108 | ||
109 | return ret; | |
110 | } | |
111 | ||
112 | /* If enabled as a wakeup-source, arm the timer when powering off */ | |
113 | static int brcmstb_waketmr_reboot(struct notifier_block *nb, | |
114 | unsigned long action, void *data) | |
115 | { | |
116 | struct brcmstb_waketmr *timer; | |
117 | ||
118 | timer = container_of(nb, struct brcmstb_waketmr, reboot_notifier); | |
119 | ||
120 | /* Set timer for cold boot */ | |
121 | if (action == SYS_POWER_OFF) | |
122 | brcmstb_waketmr_prepare_suspend(timer); | |
123 | ||
124 | return NOTIFY_DONE; | |
125 | } | |
126 | ||
127 | static int brcmstb_waketmr_gettime(struct device *dev, | |
128 | struct rtc_time *tm) | |
129 | { | |
130 | struct brcmstb_waketmr *timer = dev_get_drvdata(dev); | |
131 | struct wktmr_time now; | |
132 | ||
133 | wktmr_read(timer, &now); | |
134 | ||
135 | rtc_time_to_tm(now.sec, tm); | |
136 | ||
137 | return 0; | |
138 | } | |
139 | ||
140 | static int brcmstb_waketmr_settime(struct device *dev, | |
141 | struct rtc_time *tm) | |
142 | { | |
143 | struct brcmstb_waketmr *timer = dev_get_drvdata(dev); | |
144 | time64_t sec; | |
145 | ||
146 | sec = rtc_tm_to_time64(tm); | |
147 | ||
148 | if (sec > U32_MAX || sec < 0) | |
149 | return -EINVAL; | |
150 | ||
151 | writel_relaxed(sec, timer->base + BRCMSTB_WKTMR_COUNTER); | |
152 | ||
153 | return 0; | |
154 | } | |
155 | ||
156 | static int brcmstb_waketmr_getalarm(struct device *dev, | |
157 | struct rtc_wkalrm *alarm) | |
158 | { | |
159 | struct brcmstb_waketmr *timer = dev_get_drvdata(dev); | |
160 | time64_t sec; | |
161 | u32 reg; | |
162 | ||
163 | sec = readl_relaxed(timer->base + BRCMSTB_WKTMR_ALARM); | |
164 | if (sec != 0) { | |
165 | /* Alarm is enabled */ | |
166 | alarm->enabled = 1; | |
167 | rtc_time64_to_tm(sec, &alarm->time); | |
168 | } | |
169 | ||
170 | reg = readl_relaxed(timer->base + BRCMSTB_WKTMR_EVENT); | |
171 | alarm->pending = !!(reg & 1); | |
172 | ||
173 | return 0; | |
174 | } | |
175 | ||
176 | static int brcmstb_waketmr_setalarm(struct device *dev, | |
177 | struct rtc_wkalrm *alarm) | |
178 | { | |
179 | struct brcmstb_waketmr *timer = dev_get_drvdata(dev); | |
180 | time64_t sec; | |
181 | ||
182 | if (alarm->enabled) | |
183 | sec = rtc_tm_to_time64(&alarm->time); | |
184 | else | |
185 | sec = 0; | |
186 | ||
187 | if (sec > U32_MAX || sec < 0) | |
188 | return -EINVAL; | |
189 | ||
190 | brcmstb_waketmr_set_alarm(timer, sec); | |
191 | ||
192 | return 0; | |
193 | } | |
194 | ||
195 | /* | |
196 | * Does not do much but keep the RTC class happy. We always support | |
197 | * alarms. | |
198 | */ | |
199 | static int brcmstb_waketmr_alarm_enable(struct device *dev, | |
200 | unsigned int enabled) | |
201 | { | |
202 | return 0; | |
203 | } | |
204 | ||
205 | static const struct rtc_class_ops brcmstb_waketmr_ops = { | |
206 | .read_time = brcmstb_waketmr_gettime, | |
207 | .set_time = brcmstb_waketmr_settime, | |
208 | .read_alarm = brcmstb_waketmr_getalarm, | |
209 | .set_alarm = brcmstb_waketmr_setalarm, | |
210 | .alarm_irq_enable = brcmstb_waketmr_alarm_enable, | |
211 | }; | |
212 | ||
213 | static int brcmstb_waketmr_probe(struct platform_device *pdev) | |
214 | { | |
215 | struct device *dev = &pdev->dev; | |
216 | struct brcmstb_waketmr *timer; | |
217 | struct resource *res; | |
218 | int ret; | |
219 | ||
220 | timer = devm_kzalloc(dev, sizeof(*timer), GFP_KERNEL); | |
221 | if (!timer) | |
222 | return -ENOMEM; | |
223 | ||
224 | platform_set_drvdata(pdev, timer); | |
225 | timer->dev = dev; | |
226 | ||
227 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
228 | timer->base = devm_ioremap_resource(dev, res); | |
229 | if (IS_ERR(timer->base)) | |
230 | return PTR_ERR(timer->base); | |
231 | ||
232 | /* | |
233 | * Set wakeup capability before requesting wakeup interrupt, so we can | |
234 | * process boot-time "wakeups" (e.g., from S5 soft-off) | |
235 | */ | |
236 | device_set_wakeup_capable(dev, true); | |
237 | device_wakeup_enable(dev); | |
238 | ||
239 | timer->irq = platform_get_irq(pdev, 0); | |
240 | if (timer->irq < 0) | |
241 | return -ENODEV; | |
242 | ||
243 | timer->clk = devm_clk_get(dev, NULL); | |
244 | if (!IS_ERR(timer->clk)) { | |
245 | ret = clk_prepare_enable(timer->clk); | |
246 | if (ret) | |
247 | return ret; | |
248 | timer->rate = clk_get_rate(timer->clk); | |
249 | if (!timer->rate) | |
250 | timer->rate = BRCMSTB_WKTMR_DEFAULT_FREQ; | |
251 | } else { | |
252 | timer->rate = BRCMSTB_WKTMR_DEFAULT_FREQ; | |
253 | timer->clk = NULL; | |
254 | } | |
255 | ||
256 | ret = devm_request_irq(dev, timer->irq, brcmstb_waketmr_irq, 0, | |
257 | "brcmstb-waketimer", timer); | |
258 | if (ret < 0) | |
f2eef045 | 259 | goto err_clk; |
c4f07ece BN |
260 | |
261 | timer->reboot_notifier.notifier_call = brcmstb_waketmr_reboot; | |
262 | register_reboot_notifier(&timer->reboot_notifier); | |
263 | ||
264 | timer->rtc = rtc_device_register("brcmstb-waketmr", dev, | |
265 | &brcmstb_waketmr_ops, THIS_MODULE); | |
266 | if (IS_ERR(timer->rtc)) { | |
267 | dev_err(dev, "unable to register device\n"); | |
f2eef045 AK |
268 | ret = PTR_ERR(timer->rtc); |
269 | goto err_notifier; | |
c4f07ece BN |
270 | } |
271 | ||
272 | dev_info(dev, "registered, with irq %d\n", timer->irq); | |
273 | ||
f2eef045 AK |
274 | return 0; |
275 | ||
276 | err_notifier: | |
277 | unregister_reboot_notifier(&timer->reboot_notifier); | |
278 | ||
279 | err_clk: | |
280 | if (timer->clk) | |
281 | clk_disable_unprepare(timer->clk); | |
282 | ||
c4f07ece BN |
283 | return ret; |
284 | } | |
285 | ||
286 | static int brcmstb_waketmr_remove(struct platform_device *pdev) | |
287 | { | |
288 | struct brcmstb_waketmr *timer = dev_get_drvdata(&pdev->dev); | |
289 | ||
290 | unregister_reboot_notifier(&timer->reboot_notifier); | |
291 | rtc_device_unregister(timer->rtc); | |
292 | ||
293 | return 0; | |
294 | } | |
295 | ||
296 | #ifdef CONFIG_PM_SLEEP | |
297 | static int brcmstb_waketmr_suspend(struct device *dev) | |
298 | { | |
299 | struct brcmstb_waketmr *timer = dev_get_drvdata(dev); | |
300 | ||
301 | return brcmstb_waketmr_prepare_suspend(timer); | |
302 | } | |
303 | ||
304 | static int brcmstb_waketmr_resume(struct device *dev) | |
305 | { | |
306 | struct brcmstb_waketmr *timer = dev_get_drvdata(dev); | |
307 | int ret; | |
308 | ||
309 | if (!device_may_wakeup(dev)) | |
310 | return 0; | |
311 | ||
312 | ret = disable_irq_wake(timer->irq); | |
313 | ||
314 | brcmstb_waketmr_clear_alarm(timer); | |
315 | ||
316 | return ret; | |
317 | } | |
318 | #endif /* CONFIG_PM_SLEEP */ | |
319 | ||
320 | static SIMPLE_DEV_PM_OPS(brcmstb_waketmr_pm_ops, | |
321 | brcmstb_waketmr_suspend, brcmstb_waketmr_resume); | |
322 | ||
323 | static const struct of_device_id brcmstb_waketmr_of_match[] = { | |
324 | { .compatible = "brcm,brcmstb-waketimer" }, | |
325 | { /* sentinel */ }, | |
326 | }; | |
327 | ||
328 | static struct platform_driver brcmstb_waketmr_driver = { | |
329 | .probe = brcmstb_waketmr_probe, | |
330 | .remove = brcmstb_waketmr_remove, | |
331 | .driver = { | |
332 | .name = "brcmstb-waketimer", | |
333 | .pm = &brcmstb_waketmr_pm_ops, | |
334 | .of_match_table = of_match_ptr(brcmstb_waketmr_of_match), | |
335 | } | |
336 | }; | |
337 | module_platform_driver(brcmstb_waketmr_driver); | |
338 | ||
339 | MODULE_LICENSE("GPL v2"); | |
340 | MODULE_AUTHOR("Brian Norris"); | |
341 | MODULE_AUTHOR("Markus Mayer"); | |
342 | MODULE_DESCRIPTION("Wake-up timer driver for STB chips"); |