aboutsummaryrefslogtreecommitdiff
path: root/drivers/rtc/rtc-goldfish.c
blob: 59c0f38cc08dfe9ac69317ca6514362b027f1a7f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
// SPDX-License-Identifier: GPL-2.0
/* drivers/rtc/rtc-goldfish.c
 *
 * Copyright (C) 2007 Google, Inc.
 * Copyright (C) 2017 Imagination Technologies Ltd.
 */

#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/goldfish.h>
#include <clocksource/timer-goldfish.h>

struct goldfish_rtc {
	void __iomem *base;
	int irq;
	struct rtc_device *rtc;
};

static int goldfish_rtc_read_alarm(struct device *dev,
				   struct rtc_wkalrm *alrm)
{
	u64 rtc_alarm;
	u64 rtc_alarm_low;
	u64 rtc_alarm_high;
	void __iomem *base;
	struct goldfish_rtc *rtcdrv;

	rtcdrv = dev_get_drvdata(dev);
	base = rtcdrv->base;

	rtc_alarm_low = gf_ioread32(base + TIMER_ALARM_LOW);
	rtc_alarm_high = gf_ioread32(base + TIMER_ALARM_HIGH);
	rtc_alarm = (rtc_alarm_high << 32) | rtc_alarm_low;

	do_div(rtc_alarm, NSEC_PER_SEC);
	memset(alrm, 0, sizeof(struct rtc_wkalrm));

	rtc_time64_to_tm(rtc_alarm, &alrm->time);

	if (gf_ioread32(base + TIMER_ALARM_STATUS))
		alrm->enabled = 1;
	else
		alrm->enabled = 0;

	return 0;
}

static int goldfish_rtc_set_alarm(struct device *dev,
				  struct rtc_wkalrm *alrm)
{
	struct goldfish_rtc *rtcdrv;
	u64 rtc_alarm64;
	u64 rtc_status_reg;
	void __iomem *base;

	rtcdrv = dev_get_drvdata(dev);
	base = rtcdrv->base;

	if (alrm->enabled) {
		rtc_alarm64 = rtc_tm_to_time64(&alrm->time) * NSEC_PER_SEC;
		gf_iowrite32((rtc_alarm64 >> 32), base + TIMER_ALARM_HIGH);
		gf_iowrite32(rtc_alarm64, base + TIMER_ALARM_LOW);
		gf_iowrite32(1, base + TIMER_IRQ_ENABLED);
	} else {
		/*
		 * if this function was called with enabled=0
		 * then it could mean that the application is
		 * trying to cancel an ongoing alarm
		 */
		rtc_status_reg = gf_ioread32(base + TIMER_ALARM_STATUS);
		if (rtc_status_reg)
			gf_iowrite32(1, base + TIMER_CLEAR_ALARM);
	}

	return 0;
}

static int goldfish_rtc_alarm_irq_enable(struct device *dev,
					 unsigned int enabled)
{
	void __iomem *base;
	struct goldfish_rtc *rtcdrv;

	rtcdrv = dev_get_drvdata(dev);
	base = rtcdrv->base;

	if (enabled)
		gf_iowrite32(1, base + TIMER_IRQ_ENABLED);
	else
		gf_iowrite32(0, base + TIMER_IRQ_ENABLED);

	return 0;
}

static irqreturn_t goldfish_rtc_interrupt(int irq, void *dev_id)
{
	struct goldfish_rtc *rtcdrv = dev_id;
	void __iomem *base = rtcdrv->base;

	gf_iowrite32(1, base + TIMER_CLEAR_INTERRUPT);

	rtc_update_irq(rtcdrv->rtc, 1, RTC_IRQF | RTC_AF);

	return IRQ_HANDLED;
}

static int goldfish_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct goldfish_rtc *rtcdrv;
	void __iomem *base;
	u64 time_high;
	u64 time_low;
	u64 time;

	rtcdrv = dev_get_drvdata(dev);
	base = rtcdrv->base;

	time_low = gf_ioread32(base + TIMER_TIME_LOW);
	time_high = gf_ioread32(base + TIMER_TIME_HIGH);
	time = (time_high << 32) | time_low;

	do_div(time, NSEC_PER_SEC);

	rtc_time64_to_tm(time, tm);

	return 0;
}

static int goldfish_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct goldfish_rtc *rtcdrv;
	void __iomem *base;
	u64 now64;

	rtcdrv = dev_get_drvdata(dev);
	base = rtcdrv->base;

	now64 = rtc_tm_to_time64(tm) * NSEC_PER_SEC;
	gf_iowrite32((now64 >> 32), base + TIMER_TIME_HIGH);
	gf_iowrite32(now64, base + TIMER_TIME_LOW);

	return 0;
}

static const struct rtc_class_ops goldfish_rtc_ops = {
	.read_time	= goldfish_rtc_read_time,
	.set_time	= goldfish_rtc_set_time,
	.read_alarm	= goldfish_rtc_read_alarm,
	.set_alarm	= goldfish_rtc_set_alarm,
	.alarm_irq_enable = goldfish_rtc_alarm_irq_enable
};

static int goldfish_rtc_probe(struct platform_device *pdev)
{
	struct goldfish_rtc *rtcdrv;
	int err;

	rtcdrv = devm_kzalloc(&pdev->dev, sizeof(*rtcdrv), GFP_KERNEL);
	if (!rtcdrv)
		return -ENOMEM;

	platform_set_drvdata(pdev, rtcdrv);
	rtcdrv->base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(rtcdrv->base))
		return PTR_ERR(rtcdrv->base);

	rtcdrv->irq = platform_get_irq(pdev, 0);
	if (rtcdrv->irq < 0)
		return -ENODEV;

	rtcdrv->rtc = devm_rtc_allocate_device(&pdev->dev);
	if (IS_ERR(rtcdrv->rtc))
		return PTR_ERR(rtcdrv->rtc);

	rtcdrv->rtc->ops = &goldfish_rtc_ops;
	rtcdrv->rtc->range_max = U64_MAX / NSEC_PER_SEC;

	err = devm_request_irq(&pdev->dev, rtcdrv->irq,
			       goldfish_rtc_interrupt,
			       0, pdev->name, rtcdrv);
	if (err)
		return err;

	return devm_rtc_register_device(rtcdrv->rtc);
}

static const struct of_device_id goldfish_rtc_of_match[] = {
	{ .compatible = "google,goldfish-rtc", },
	{},
};
MODULE_DEVICE_TABLE(of, goldfish_rtc_of_match);

static struct platform_driver goldfish_rtc = {
	.probe = goldfish_rtc_probe,
	.driver = {
		.name = "goldfish_rtc",
		.of_match_table = goldfish_rtc_of_match,
	}
};

module_platform_driver(goldfish_rtc);

MODULE_LICENSE("GPL v2");