1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright © 2014-2017 Broadcom
6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9 #include <linux/device.h>
10 #include <linux/err.h>
11 #include <linux/init.h>
12 #include <linux/interrupt.h>
14 #include <linux/irqreturn.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
18 #include <linux/platform_device.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>
26 struct brcmstb_waketmr {
27 struct rtc_device *rtc;
31 struct notifier_block reboot_notifier;
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
42 #define BRCMSTB_WKTMR_DEFAULT_FREQ 27000000
44 static inline void brcmstb_waketmr_clear_alarm(struct brcmstb_waketmr *timer)
46 writel_relaxed(1, timer->base + BRCMSTB_WKTMR_EVENT);
47 (void)readl_relaxed(timer->base + BRCMSTB_WKTMR_EVENT);
50 static void brcmstb_waketmr_set_alarm(struct brcmstb_waketmr *timer,
53 brcmstb_waketmr_clear_alarm(timer);
55 /* Make sure we are actually counting in seconds */
56 writel_relaxed(timer->rate, timer->base + BRCMSTB_WKTMR_PRESCALER);
58 writel_relaxed(secs + 1, timer->base + BRCMSTB_WKTMR_ALARM);
61 static irqreturn_t brcmstb_waketmr_irq(int irq, void *data)
63 struct brcmstb_waketmr *timer = data;
65 pm_wakeup_event(timer->dev, 0);
75 static void wktmr_read(struct brcmstb_waketmr *timer,
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);
85 t->pre = timer->rate - tmp;
88 static int brcmstb_waketmr_prepare_suspend(struct brcmstb_waketmr *timer)
90 struct device *dev = timer->dev;
93 if (device_may_wakeup(dev)) {
94 ret = enable_irq_wake(timer->irq);
96 dev_err(dev, "failed to enable wake-up interrupt\n");
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)
108 struct brcmstb_waketmr *timer;
110 timer = container_of(nb, struct brcmstb_waketmr, reboot_notifier);
112 /* Set timer for cold boot */
113 if (action == SYS_POWER_OFF)
114 brcmstb_waketmr_prepare_suspend(timer);
119 static int brcmstb_waketmr_gettime(struct device *dev,
122 struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
123 struct wktmr_time now;
125 wktmr_read(timer, &now);
127 rtc_time64_to_tm(now.sec, tm);
132 static int brcmstb_waketmr_settime(struct device *dev,
135 struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
138 sec = rtc_tm_to_time64(tm);
140 writel_relaxed(sec, timer->base + BRCMSTB_WKTMR_COUNTER);
145 static int brcmstb_waketmr_getalarm(struct device *dev,
146 struct rtc_wkalrm *alarm)
148 struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
152 sec = readl_relaxed(timer->base + BRCMSTB_WKTMR_ALARM);
154 /* Alarm is enabled */
156 rtc_time64_to_tm(sec, &alarm->time);
159 reg = readl_relaxed(timer->base + BRCMSTB_WKTMR_EVENT);
160 alarm->pending = !!(reg & 1);
165 static int brcmstb_waketmr_setalarm(struct device *dev,
166 struct rtc_wkalrm *alarm)
168 struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
172 sec = rtc_tm_to_time64(&alarm->time);
176 brcmstb_waketmr_set_alarm(timer, sec);
182 * Does not do much but keep the RTC class happy. We always support
185 static int brcmstb_waketmr_alarm_enable(struct device *dev,
186 unsigned int enabled)
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,
199 static int brcmstb_waketmr_probe(struct platform_device *pdev)
201 struct device *dev = &pdev->dev;
202 struct brcmstb_waketmr *timer;
205 timer = devm_kzalloc(dev, sizeof(*timer), GFP_KERNEL);
209 platform_set_drvdata(pdev, timer);
212 timer->base = devm_platform_ioremap_resource(pdev, 0);
213 if (IS_ERR(timer->base))
214 return PTR_ERR(timer->base);
216 timer->rtc = devm_rtc_allocate_device(dev);
217 if (IS_ERR(timer->rtc))
218 return PTR_ERR(timer->rtc);
221 * Set wakeup capability before requesting wakeup interrupt, so we can
222 * process boot-time "wakeups" (e.g., from S5 soft-off)
224 device_set_wakeup_capable(dev, true);
225 device_wakeup_enable(dev);
227 timer->irq = platform_get_irq(pdev, 0);
231 timer->clk = devm_clk_get(dev, NULL);
232 if (!IS_ERR(timer->clk)) {
233 ret = clk_prepare_enable(timer->clk);
236 timer->rate = clk_get_rate(timer->clk);
238 timer->rate = BRCMSTB_WKTMR_DEFAULT_FREQ;
240 timer->rate = BRCMSTB_WKTMR_DEFAULT_FREQ;
244 ret = devm_request_irq(dev, timer->irq, brcmstb_waketmr_irq, 0,
245 "brcmstb-waketimer", timer);
249 timer->reboot_notifier.notifier_call = brcmstb_waketmr_reboot;
250 register_reboot_notifier(&timer->reboot_notifier);
252 timer->rtc->ops = &brcmstb_waketmr_ops;
253 timer->rtc->range_max = U32_MAX;
255 ret = rtc_register_device(timer->rtc);
259 dev_info(dev, "registered, with irq %d\n", timer->irq);
264 unregister_reboot_notifier(&timer->reboot_notifier);
268 clk_disable_unprepare(timer->clk);
273 static int brcmstb_waketmr_remove(struct platform_device *pdev)
275 struct brcmstb_waketmr *timer = dev_get_drvdata(&pdev->dev);
277 unregister_reboot_notifier(&timer->reboot_notifier);
278 clk_disable_unprepare(timer->clk);
283 #ifdef CONFIG_PM_SLEEP
284 static int brcmstb_waketmr_suspend(struct device *dev)
286 struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
288 return brcmstb_waketmr_prepare_suspend(timer);
291 static int brcmstb_waketmr_resume(struct device *dev)
293 struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
296 if (!device_may_wakeup(dev))
299 ret = disable_irq_wake(timer->irq);
301 brcmstb_waketmr_clear_alarm(timer);
305 #endif /* CONFIG_PM_SLEEP */
307 static SIMPLE_DEV_PM_OPS(brcmstb_waketmr_pm_ops,
308 brcmstb_waketmr_suspend, brcmstb_waketmr_resume);
310 static const struct of_device_id brcmstb_waketmr_of_match[] = {
311 { .compatible = "brcm,brcmstb-waketimer" },
315 static struct platform_driver brcmstb_waketmr_driver = {
316 .probe = brcmstb_waketmr_probe,
317 .remove = brcmstb_waketmr_remove,
319 .name = "brcmstb-waketimer",
320 .pm = &brcmstb_waketmr_pm_ops,
321 .of_match_table = of_match_ptr(brcmstb_waketmr_of_match),
324 module_platform_driver(brcmstb_waketmr_driver);
326 MODULE_LICENSE("GPL v2");
327 MODULE_AUTHOR("Brian Norris");
328 MODULE_AUTHOR("Markus Mayer");
329 MODULE_DESCRIPTION("Wake-up timer driver for STB chips");