blob: ba49d9bcff12253922bdd04075f9043c424e7186 [file] [log] [blame]
Brian Norrisc4f07ec2017-06-26 14:15:03 -07001/*
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
34struct 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
52static 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
58static void brcmstb_waketmr_set_alarm(struct brcmstb_waketmr *timer,
59 unsigned int secs)
60{
61 brcmstb_waketmr_clear_alarm(timer);
62
Justin Chen58d3d5e2018-02-26 12:09:58 -080063 /* Make sure we are actually counting in seconds */
64 writel_relaxed(timer->rate, timer->base + BRCMSTB_WKTMR_PRESCALER);
65
Brian Norrisc4f07ec2017-06-26 14:15:03 -070066 writel_relaxed(secs + 1, timer->base + BRCMSTB_WKTMR_ALARM);
67}
68
69static 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
78struct wktmr_time {
79 u32 sec;
80 u32 pre;
81};
82
83static 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
96static 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 */
113static 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
127static 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
140static 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
156static 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
176static 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 */
199static int brcmstb_waketmr_alarm_enable(struct device *dev,
200 unsigned int enabled)
201{
202 return 0;
203}
204
205static 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
213static 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
Alexandre Belloni2abf2862018-05-20 22:27:29 +0200232 timer->rtc = devm_rtc_allocate_device(dev);
233 if (IS_ERR(timer->rtc))
234 return PTR_ERR(timer->rtc);
235
Brian Norrisc4f07ec2017-06-26 14:15:03 -0700236 /*
237 * Set wakeup capability before requesting wakeup interrupt, so we can
238 * process boot-time "wakeups" (e.g., from S5 soft-off)
239 */
240 device_set_wakeup_capable(dev, true);
241 device_wakeup_enable(dev);
242
243 timer->irq = platform_get_irq(pdev, 0);
244 if (timer->irq < 0)
245 return -ENODEV;
246
247 timer->clk = devm_clk_get(dev, NULL);
248 if (!IS_ERR(timer->clk)) {
249 ret = clk_prepare_enable(timer->clk);
250 if (ret)
251 return ret;
252 timer->rate = clk_get_rate(timer->clk);
253 if (!timer->rate)
254 timer->rate = BRCMSTB_WKTMR_DEFAULT_FREQ;
255 } else {
256 timer->rate = BRCMSTB_WKTMR_DEFAULT_FREQ;
257 timer->clk = NULL;
258 }
259
260 ret = devm_request_irq(dev, timer->irq, brcmstb_waketmr_irq, 0,
261 "brcmstb-waketimer", timer);
262 if (ret < 0)
Alexey Khoroshilovf2eef042017-11-18 00:15:58 +0300263 goto err_clk;
Brian Norrisc4f07ec2017-06-26 14:15:03 -0700264
265 timer->reboot_notifier.notifier_call = brcmstb_waketmr_reboot;
266 register_reboot_notifier(&timer->reboot_notifier);
267
Alexandre Belloni2abf2862018-05-20 22:27:29 +0200268 timer->rtc->ops = &brcmstb_waketmr_ops;
269
270 ret = rtc_register_device(timer->rtc);
271 if (ret) {
Brian Norrisc4f07ec2017-06-26 14:15:03 -0700272 dev_err(dev, "unable to register device\n");
Alexey Khoroshilovf2eef042017-11-18 00:15:58 +0300273 goto err_notifier;
Brian Norrisc4f07ec2017-06-26 14:15:03 -0700274 }
275
276 dev_info(dev, "registered, with irq %d\n", timer->irq);
277
Alexey Khoroshilovf2eef042017-11-18 00:15:58 +0300278 return 0;
279
280err_notifier:
281 unregister_reboot_notifier(&timer->reboot_notifier);
282
283err_clk:
284 if (timer->clk)
285 clk_disable_unprepare(timer->clk);
286
Brian Norrisc4f07ec2017-06-26 14:15:03 -0700287 return ret;
288}
289
290static int brcmstb_waketmr_remove(struct platform_device *pdev)
291{
292 struct brcmstb_waketmr *timer = dev_get_drvdata(&pdev->dev);
293
294 unregister_reboot_notifier(&timer->reboot_notifier);
Brian Norrisc4f07ec2017-06-26 14:15:03 -0700295
296 return 0;
297}
298
299#ifdef CONFIG_PM_SLEEP
300static int brcmstb_waketmr_suspend(struct device *dev)
301{
302 struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
303
304 return brcmstb_waketmr_prepare_suspend(timer);
305}
306
307static int brcmstb_waketmr_resume(struct device *dev)
308{
309 struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
310 int ret;
311
312 if (!device_may_wakeup(dev))
313 return 0;
314
315 ret = disable_irq_wake(timer->irq);
316
317 brcmstb_waketmr_clear_alarm(timer);
318
319 return ret;
320}
321#endif /* CONFIG_PM_SLEEP */
322
323static SIMPLE_DEV_PM_OPS(brcmstb_waketmr_pm_ops,
324 brcmstb_waketmr_suspend, brcmstb_waketmr_resume);
325
326static const struct of_device_id brcmstb_waketmr_of_match[] = {
327 { .compatible = "brcm,brcmstb-waketimer" },
328 { /* sentinel */ },
329};
330
331static struct platform_driver brcmstb_waketmr_driver = {
332 .probe = brcmstb_waketmr_probe,
333 .remove = brcmstb_waketmr_remove,
334 .driver = {
335 .name = "brcmstb-waketimer",
336 .pm = &brcmstb_waketmr_pm_ops,
337 .of_match_table = of_match_ptr(brcmstb_waketmr_of_match),
338 }
339};
340module_platform_driver(brcmstb_waketmr_driver);
341
342MODULE_LICENSE("GPL v2");
343MODULE_AUTHOR("Brian Norris");
344MODULE_AUTHOR("Markus Mayer");
345MODULE_DESCRIPTION("Wake-up timer driver for STB chips");