1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2019 BayLibre, SAS
4 * Author: Neil Armstrong <narmstrong@baylibre.com>
5 * Copyright (C) 2015 Amlogic, Inc. All rights reserved.
6 */
7 #include <linux/module.h>
8 #include <linux/platform_device.h>
9 #include <linux/rtc.h>
10 #include <linux/io.h>
11 #include <linux/of.h>
12 #include <linux/time64.h>
13
14 struct meson_vrtc_data {
15 void __iomem *io_alarm;
16 struct rtc_device *rtc;
17 unsigned long alarm_time;
18 bool enabled;
19 };
20
meson_vrtc_read_time(struct device * dev,struct rtc_time * tm)21 static int meson_vrtc_read_time(struct device *dev, struct rtc_time *tm)
22 {
23 struct timespec64 time;
24
25 dev_dbg(dev, "%s\n", __func__);
26 ktime_get_real_ts64(&time);
27 rtc_time64_to_tm(time.tv_sec, tm);
28
29 return 0;
30 }
31
meson_vrtc_set_wakeup_time(struct meson_vrtc_data * vrtc,unsigned long time)32 static void meson_vrtc_set_wakeup_time(struct meson_vrtc_data *vrtc,
33 unsigned long time)
34 {
35 writel_relaxed(time, vrtc->io_alarm);
36 }
37
meson_vrtc_set_alarm(struct device * dev,struct rtc_wkalrm * alarm)38 static int meson_vrtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
39 {
40 struct meson_vrtc_data *vrtc = dev_get_drvdata(dev);
41
42 dev_dbg(dev, "%s: alarm->enabled=%d\n", __func__, alarm->enabled);
43 if (alarm->enabled)
44 vrtc->alarm_time = rtc_tm_to_time64(&alarm->time);
45 else
46 vrtc->alarm_time = 0;
47
48 return 0;
49 }
50
meson_vrtc_alarm_irq_enable(struct device * dev,unsigned int enabled)51 static int meson_vrtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
52 {
53 struct meson_vrtc_data *vrtc = dev_get_drvdata(dev);
54
55 vrtc->enabled = enabled;
56 return 0;
57 }
58
59 static const struct rtc_class_ops meson_vrtc_ops = {
60 .read_time = meson_vrtc_read_time,
61 .set_alarm = meson_vrtc_set_alarm,
62 .alarm_irq_enable = meson_vrtc_alarm_irq_enable,
63 };
64
meson_vrtc_probe(struct platform_device * pdev)65 static int meson_vrtc_probe(struct platform_device *pdev)
66 {
67 struct meson_vrtc_data *vrtc;
68
69 vrtc = devm_kzalloc(&pdev->dev, sizeof(*vrtc), GFP_KERNEL);
70 if (!vrtc)
71 return -ENOMEM;
72
73 vrtc->io_alarm = devm_platform_ioremap_resource(pdev, 0);
74 if (IS_ERR(vrtc->io_alarm))
75 return PTR_ERR(vrtc->io_alarm);
76
77 device_init_wakeup(&pdev->dev, 1);
78
79 platform_set_drvdata(pdev, vrtc);
80
81 vrtc->rtc = devm_rtc_allocate_device(&pdev->dev);
82 if (IS_ERR(vrtc->rtc))
83 return PTR_ERR(vrtc->rtc);
84
85 vrtc->rtc->ops = &meson_vrtc_ops;
86 return devm_rtc_register_device(vrtc->rtc);
87 }
88
meson_vrtc_suspend(struct device * dev)89 static int __maybe_unused meson_vrtc_suspend(struct device *dev)
90 {
91 struct meson_vrtc_data *vrtc = dev_get_drvdata(dev);
92
93 dev_dbg(dev, "%s\n", __func__);
94 if (vrtc->alarm_time) {
95 unsigned long local_time;
96 long alarm_secs;
97 struct timespec64 time;
98
99 ktime_get_real_ts64(&time);
100 local_time = time.tv_sec;
101
102 dev_dbg(dev, "alarm_time = %lus, local_time=%lus\n",
103 vrtc->alarm_time, local_time);
104 alarm_secs = vrtc->alarm_time - local_time;
105 if (alarm_secs > 0) {
106 meson_vrtc_set_wakeup_time(vrtc, alarm_secs);
107 dev_dbg(dev, "system will wakeup in %lds.\n",
108 alarm_secs);
109 } else {
110 dev_err(dev, "alarm time already passed: %lds.\n",
111 alarm_secs);
112 }
113 }
114
115 return 0;
116 }
117
meson_vrtc_resume(struct device * dev)118 static int __maybe_unused meson_vrtc_resume(struct device *dev)
119 {
120 struct meson_vrtc_data *vrtc = dev_get_drvdata(dev);
121
122 dev_dbg(dev, "%s\n", __func__);
123
124 vrtc->alarm_time = 0;
125 meson_vrtc_set_wakeup_time(vrtc, 0);
126 return 0;
127 }
128
129 static SIMPLE_DEV_PM_OPS(meson_vrtc_pm_ops,
130 meson_vrtc_suspend, meson_vrtc_resume);
131
132 static const struct of_device_id meson_vrtc_dt_match[] = {
133 { .compatible = "amlogic,meson-vrtc"},
134 {},
135 };
136 MODULE_DEVICE_TABLE(of, meson_vrtc_dt_match);
137
138 static struct platform_driver meson_vrtc_driver = {
139 .probe = meson_vrtc_probe,
140 .driver = {
141 .name = "meson-vrtc",
142 .of_match_table = meson_vrtc_dt_match,
143 .pm = &meson_vrtc_pm_ops,
144 },
145 };
146
147 module_platform_driver(meson_vrtc_driver);
148
149 MODULE_DESCRIPTION("Amlogic Virtual Wakeup RTC Timer driver");
150 MODULE_LICENSE("GPL");
151
