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2be7f1b5 | 1 | // SPDX-License-Identifier: GPL-2.0 |
f22d9cdc MD |
2 | /* drivers/rtc/rtc-goldfish.c |
3 | * | |
4 | * Copyright (C) 2007 Google, Inc. | |
5 | * Copyright (C) 2017 Imagination Technologies Ltd. | |
f22d9cdc MD |
6 | */ |
7 | ||
bd01386e | 8 | #include <linux/io.h> |
f22d9cdc | 9 | #include <linux/module.h> |
6a6ec8c1 | 10 | #include <linux/of.h> |
f22d9cdc MD |
11 | #include <linux/platform_device.h> |
12 | #include <linux/rtc.h> | |
f22d9cdc MD |
13 | |
14 | #define TIMER_TIME_LOW 0x00 /* get low bits of current time */ | |
15 | /* and update TIMER_TIME_HIGH */ | |
16 | #define TIMER_TIME_HIGH 0x04 /* get high bits of time at last */ | |
17 | /* TIMER_TIME_LOW read */ | |
18 | #define TIMER_ALARM_LOW 0x08 /* set low bits of alarm and */ | |
19 | /* activate it */ | |
20 | #define TIMER_ALARM_HIGH 0x0c /* set high bits of next alarm */ | |
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 | ||
26 | struct goldfish_rtc { | |
27 | void __iomem *base; | |
28 | int irq; | |
29 | struct rtc_device *rtc; | |
30 | }; | |
31 | ||
32 | static 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 | ||
b509306d | 51 | rtc_time64_to_tm(rtc_alarm, &alrm->time); |
f22d9cdc MD |
52 | |
53 | if (readl(base + TIMER_ALARM_STATUS)) | |
54 | alrm->enabled = 1; | |
55 | else | |
56 | alrm->enabled = 0; | |
57 | ||
58 | return 0; | |
59 | } | |
60 | ||
61 | static int goldfish_rtc_set_alarm(struct device *dev, | |
62 | struct rtc_wkalrm *alrm) | |
63 | { | |
64 | struct goldfish_rtc *rtcdrv; | |
f22d9cdc MD |
65 | u64 rtc_alarm64; |
66 | u64 rtc_status_reg; | |
67 | void __iomem *base; | |
f22d9cdc MD |
68 | |
69 | rtcdrv = dev_get_drvdata(dev); | |
70 | base = rtcdrv->base; | |
71 | ||
72 | if (alrm->enabled) { | |
b509306d | 73 | rtc_alarm64 = rtc_tm_to_time64(&alrm->time) * NSEC_PER_SEC; |
f22d9cdc MD |
74 | writel((rtc_alarm64 >> 32), base + TIMER_ALARM_HIGH); |
75 | writel(rtc_alarm64, base + TIMER_ALARM_LOW); | |
76 | } else { | |
77 | /* | |
78 | * if this function was called with enabled=0 | |
79 | * then it could mean that the application is | |
80 | * trying to cancel an ongoing alarm | |
81 | */ | |
82 | rtc_status_reg = readl(base + TIMER_ALARM_STATUS); | |
83 | if (rtc_status_reg) | |
84 | writel(1, base + TIMER_CLEAR_ALARM); | |
85 | } | |
86 | ||
b509306d | 87 | return 0; |
f22d9cdc MD |
88 | } |
89 | ||
90 | static int goldfish_rtc_alarm_irq_enable(struct device *dev, | |
91 | unsigned int enabled) | |
92 | { | |
93 | void __iomem *base; | |
94 | struct goldfish_rtc *rtcdrv; | |
95 | ||
96 | rtcdrv = dev_get_drvdata(dev); | |
97 | base = rtcdrv->base; | |
98 | ||
99 | if (enabled) | |
100 | writel(1, base + TIMER_IRQ_ENABLED); | |
101 | else | |
102 | writel(0, base + TIMER_IRQ_ENABLED); | |
103 | ||
104 | return 0; | |
105 | } | |
106 | ||
107 | static irqreturn_t goldfish_rtc_interrupt(int irq, void *dev_id) | |
108 | { | |
109 | struct goldfish_rtc *rtcdrv = dev_id; | |
110 | void __iomem *base = rtcdrv->base; | |
111 | ||
112 | writel(1, base + TIMER_CLEAR_INTERRUPT); | |
113 | ||
114 | rtc_update_irq(rtcdrv->rtc, 1, RTC_IRQF | RTC_AF); | |
115 | ||
116 | return IRQ_HANDLED; | |
117 | } | |
118 | ||
119 | static int goldfish_rtc_read_time(struct device *dev, struct rtc_time *tm) | |
120 | { | |
121 | struct goldfish_rtc *rtcdrv; | |
122 | void __iomem *base; | |
123 | u64 time_high; | |
124 | u64 time_low; | |
125 | u64 time; | |
126 | ||
127 | rtcdrv = dev_get_drvdata(dev); | |
128 | base = rtcdrv->base; | |
129 | ||
130 | time_low = readl(base + TIMER_TIME_LOW); | |
131 | time_high = readl(base + TIMER_TIME_HIGH); | |
132 | time = (time_high << 32) | time_low; | |
133 | ||
134 | do_div(time, NSEC_PER_SEC); | |
135 | ||
b509306d | 136 | rtc_time64_to_tm(time, tm); |
f22d9cdc MD |
137 | |
138 | return 0; | |
139 | } | |
140 | ||
141 | static int goldfish_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
142 | { | |
143 | struct goldfish_rtc *rtcdrv; | |
144 | void __iomem *base; | |
f22d9cdc | 145 | u64 now64; |
f22d9cdc MD |
146 | |
147 | rtcdrv = dev_get_drvdata(dev); | |
148 | base = rtcdrv->base; | |
149 | ||
b509306d AB |
150 | now64 = rtc_tm_to_time64(tm) * NSEC_PER_SEC; |
151 | writel((now64 >> 32), base + TIMER_TIME_HIGH); | |
152 | writel(now64, base + TIMER_TIME_LOW); | |
f22d9cdc | 153 | |
b509306d | 154 | return 0; |
f22d9cdc MD |
155 | } |
156 | ||
157 | static const struct rtc_class_ops goldfish_rtc_ops = { | |
158 | .read_time = goldfish_rtc_read_time, | |
159 | .set_time = goldfish_rtc_set_time, | |
160 | .read_alarm = goldfish_rtc_read_alarm, | |
161 | .set_alarm = goldfish_rtc_set_alarm, | |
162 | .alarm_irq_enable = goldfish_rtc_alarm_irq_enable | |
163 | }; | |
164 | ||
165 | static int goldfish_rtc_probe(struct platform_device *pdev) | |
166 | { | |
167 | struct goldfish_rtc *rtcdrv; | |
168 | struct resource *r; | |
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 | ||
177 | r = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
178 | if (!r) | |
179 | return -ENODEV; | |
180 | ||
181 | rtcdrv->base = devm_ioremap_resource(&pdev->dev, r); | |
182 | if (IS_ERR(rtcdrv->base)) | |
183 | return -ENODEV; | |
184 | ||
185 | rtcdrv->irq = platform_get_irq(pdev, 0); | |
186 | if (rtcdrv->irq < 0) | |
187 | return -ENODEV; | |
188 | ||
409b84e3 | 189 | rtcdrv->rtc = devm_rtc_allocate_device(&pdev->dev); |
f22d9cdc MD |
190 | if (IS_ERR(rtcdrv->rtc)) |
191 | return PTR_ERR(rtcdrv->rtc); | |
192 | ||
409b84e3 | 193 | rtcdrv->rtc->ops = &goldfish_rtc_ops; |
5e2954fd | 194 | rtcdrv->rtc->range_max = U64_MAX / NSEC_PER_SEC; |
409b84e3 | 195 | |
f22d9cdc MD |
196 | err = devm_request_irq(&pdev->dev, rtcdrv->irq, |
197 | goldfish_rtc_interrupt, | |
198 | 0, pdev->name, rtcdrv); | |
199 | if (err) | |
200 | return err; | |
201 | ||
409b84e3 | 202 | return rtc_register_device(rtcdrv->rtc); |
f22d9cdc MD |
203 | } |
204 | ||
205 | static const struct of_device_id goldfish_rtc_of_match[] = { | |
206 | { .compatible = "google,goldfish-rtc", }, | |
207 | {}, | |
208 | }; | |
209 | MODULE_DEVICE_TABLE(of, goldfish_rtc_of_match); | |
210 | ||
211 | static struct platform_driver goldfish_rtc = { | |
212 | .probe = goldfish_rtc_probe, | |
213 | .driver = { | |
214 | .name = "goldfish_rtc", | |
215 | .of_match_table = goldfish_rtc_of_match, | |
216 | } | |
217 | }; | |
218 | ||
219 | module_platform_driver(goldfish_rtc); | |
82d632b8 JH |
220 | |
221 | MODULE_LICENSE("GPL v2"); |