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8#include <linux/io.h>
9#include <linux/module.h>
10#include <linux/of.h>
11#include <linux/platform_device.h>
12#include <linux/rtc.h>
13
14#define TIMER_TIME_LOW 0x00
15
16#define TIMER_TIME_HIGH 0x04
17
18#define TIMER_ALARM_LOW 0x08
19
20#define TIMER_ALARM_HIGH 0x0c
21#define TIMER_IRQ_ENABLED 0x10
22#define TIMER_CLEAR_ALARM 0x14
23#define TIMER_ALARM_STATUS 0x18
24#define TIMER_CLEAR_INTERRUPT 0x1c
25
26struct goldfish_rtc {
27 void __iomem *base;
28 int irq;
29 struct rtc_device *rtc;
30};
31
32static int goldfish_rtc_read_alarm(struct device *dev,
33 struct rtc_wkalrm *alrm)
34{
35 u64 rtc_alarm;
36 u64 rtc_alarm_low;
37 u64 rtc_alarm_high;
38 void __iomem *base;
39 struct goldfish_rtc *rtcdrv;
40
41 rtcdrv = dev_get_drvdata(dev);
42 base = rtcdrv->base;
43
44 rtc_alarm_low = readl(base + TIMER_ALARM_LOW);
45 rtc_alarm_high = readl(base + TIMER_ALARM_HIGH);
46 rtc_alarm = (rtc_alarm_high << 32) | rtc_alarm_low;
47
48 do_div(rtc_alarm, NSEC_PER_SEC);
49 memset(alrm, 0, sizeof(struct rtc_wkalrm));
50
51 rtc_time64_to_tm(rtc_alarm, &alrm->time);
52
53 if (readl(base + TIMER_ALARM_STATUS))
54 alrm->enabled = 1;
55 else
56 alrm->enabled = 0;
57
58 return 0;
59}
60
61static int goldfish_rtc_set_alarm(struct device *dev,
62 struct rtc_wkalrm *alrm)
63{
64 struct goldfish_rtc *rtcdrv;
65 u64 rtc_alarm64;
66 u64 rtc_status_reg;
67 void __iomem *base;
68
69 rtcdrv = dev_get_drvdata(dev);
70 base = rtcdrv->base;
71
72 if (alrm->enabled) {
73 rtc_alarm64 = rtc_tm_to_time64(&alrm->time) * NSEC_PER_SEC;
74 writel((rtc_alarm64 >> 32), base + TIMER_ALARM_HIGH);
75 writel(rtc_alarm64, base + TIMER_ALARM_LOW);
76 writel(1, base + TIMER_IRQ_ENABLED);
77 } else {
78
79
80
81
82
83 rtc_status_reg = readl(base + TIMER_ALARM_STATUS);
84 if (rtc_status_reg)
85 writel(1, base + TIMER_CLEAR_ALARM);
86 }
87
88 return 0;
89}
90
91static int goldfish_rtc_alarm_irq_enable(struct device *dev,
92 unsigned int enabled)
93{
94 void __iomem *base;
95 struct goldfish_rtc *rtcdrv;
96
97 rtcdrv = dev_get_drvdata(dev);
98 base = rtcdrv->base;
99
100 if (enabled)
101 writel(1, base + TIMER_IRQ_ENABLED);
102 else
103 writel(0, base + TIMER_IRQ_ENABLED);
104
105 return 0;
106}
107
108static irqreturn_t goldfish_rtc_interrupt(int irq, void *dev_id)
109{
110 struct goldfish_rtc *rtcdrv = dev_id;
111 void __iomem *base = rtcdrv->base;
112
113 writel(1, base + TIMER_CLEAR_INTERRUPT);
114
115 rtc_update_irq(rtcdrv->rtc, 1, RTC_IRQF | RTC_AF);
116
117 return IRQ_HANDLED;
118}
119
120static int goldfish_rtc_read_time(struct device *dev, struct rtc_time *tm)
121{
122 struct goldfish_rtc *rtcdrv;
123 void __iomem *base;
124 u64 time_high;
125 u64 time_low;
126 u64 time;
127
128 rtcdrv = dev_get_drvdata(dev);
129 base = rtcdrv->base;
130
131 time_low = readl(base + TIMER_TIME_LOW);
132 time_high = readl(base + TIMER_TIME_HIGH);
133 time = (time_high << 32) | time_low;
134
135 do_div(time, NSEC_PER_SEC);
136
137 rtc_time64_to_tm(time, tm);
138
139 return 0;
140}
141
142static int goldfish_rtc_set_time(struct device *dev, struct rtc_time *tm)
143{
144 struct goldfish_rtc *rtcdrv;
145 void __iomem *base;
146 u64 now64;
147
148 rtcdrv = dev_get_drvdata(dev);
149 base = rtcdrv->base;
150
151 now64 = rtc_tm_to_time64(tm) * NSEC_PER_SEC;
152 writel((now64 >> 32), base + TIMER_TIME_HIGH);
153 writel(now64, base + TIMER_TIME_LOW);
154
155 return 0;
156}
157
158static const struct rtc_class_ops goldfish_rtc_ops = {
159 .read_time = goldfish_rtc_read_time,
160 .set_time = goldfish_rtc_set_time,
161 .read_alarm = goldfish_rtc_read_alarm,
162 .set_alarm = goldfish_rtc_set_alarm,
163 .alarm_irq_enable = goldfish_rtc_alarm_irq_enable
164};
165
166static int goldfish_rtc_probe(struct platform_device *pdev)
167{
168 struct goldfish_rtc *rtcdrv;
169 int err;
170
171 rtcdrv = devm_kzalloc(&pdev->dev, sizeof(*rtcdrv), GFP_KERNEL);
172 if (!rtcdrv)
173 return -ENOMEM;
174
175 platform_set_drvdata(pdev, rtcdrv);
176 rtcdrv->base = devm_platform_ioremap_resource(pdev, 0);
177 if (IS_ERR(rtcdrv->base))
178 return PTR_ERR(rtcdrv->base);
179
180 rtcdrv->irq = platform_get_irq(pdev, 0);
181 if (rtcdrv->irq < 0)
182 return -ENODEV;
183
184 rtcdrv->rtc = devm_rtc_allocate_device(&pdev->dev);
185 if (IS_ERR(rtcdrv->rtc))
186 return PTR_ERR(rtcdrv->rtc);
187
188 rtcdrv->rtc->ops = &goldfish_rtc_ops;
189 rtcdrv->rtc->range_max = U64_MAX / NSEC_PER_SEC;
190
191 err = devm_request_irq(&pdev->dev, rtcdrv->irq,
192 goldfish_rtc_interrupt,
193 0, pdev->name, rtcdrv);
194 if (err)
195 return err;
196
197 return rtc_register_device(rtcdrv->rtc);
198}
199
200static const struct of_device_id goldfish_rtc_of_match[] = {
201 { .compatible = "google,goldfish-rtc", },
202 {},
203};
204MODULE_DEVICE_TABLE(of, goldfish_rtc_of_match);
205
206static struct platform_driver goldfish_rtc = {
207 .probe = goldfish_rtc_probe,
208 .driver = {
209 .name = "goldfish_rtc",
210 .of_match_table = goldfish_rtc_of_match,
211 }
212};
213
214module_platform_driver(goldfish_rtc);
215
216MODULE_LICENSE("GPL v2");
217
