aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/rtc/rtc-pl031.c
blob: d6d1c5726b0ee87347e9532a1da267c6cb1c79e3 (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
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
/*
 * drivers/rtc/rtc-pl031.c
 *
 * Real Time Clock interface for ARM AMBA PrimeCell 031 RTC
 *
 * Author: Deepak Saxena <dsaxena@plexity.net>
 *
 * Copyright 2006 (c) MontaVista Software, Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/rtc.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/interrupt.h>
#include <linux/string.h>
#include <linux/pm.h>

#include <linux/amba/bus.h>

#include <asm/io.h>
#include <asm/bitops.h>
#include <asm/hardware.h>
#include <asm/irq.h>
#include <asm/rtc.h>

/*
 * Register definitions
 */
#define	RTC_DR		0x00	/* Data read register */
#define	RTC_MR		0x04	/* Match register */
#define	RTC_LR		0x08	/* Data load register */
#define	RTC_CR		0x0c	/* Control register */
#define	RTC_IMSC	0x10	/* Interrupt mask and set register */
#define	RTC_RIS		0x14	/* Raw interrupt status register */
#define	RTC_MIS		0x18	/* Masked interrupt status register */
#define	RTC_ICR		0x1c	/* Interrupt clear register */

struct pl031_local {
	struct rtc_device *rtc;
	void __iomem *base;
};

static irqreturn_t pl031_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	struct rtc_device *rtc = dev_id;

	rtc_update_irq(&rtc->class_dev, 1, RTC_AF);

	return IRQ_HANDLED;
}

static int pl031_open(struct device *dev)
{
	/*
	 * We request IRQ in pl031_probe, so nothing to do here...
	 */
	return 0;
}

static void pl031_release(struct device *dev)
{
}

static int pl031_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
	struct pl031_local *ldata = dev_get_drvdata(dev);

	switch (cmd) {
	case RTC_AIE_OFF:
		__raw_writel(1, ldata->base + RTC_MIS);
		return 0;
	case RTC_AIE_ON:
		__raw_writel(0, ldata->base + RTC_MIS);
		return 0;
	}

	return -ENOIOCTLCMD;
}

static int pl031_read_time(struct device *dev, struct rtc_time *tm)
{
	struct pl031_local *ldata = dev_get_drvdata(dev);

	rtc_time_to_tm(__raw_readl(ldata->base + RTC_DR), tm);

	return 0;
}

static int pl031_set_time(struct device *dev, struct rtc_time *tm)
{
	unsigned long time;
	struct pl031_local *ldata = dev_get_drvdata(dev);

	rtc_tm_to_time(tm, &time);
	__raw_writel(time, ldata->base + RTC_LR);

	return 0;
}

static int pl031_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
	struct pl031_local *ldata = dev_get_drvdata(dev);

	rtc_time_to_tm(__raw_readl(ldata->base + RTC_MR), &alarm->time);
	alarm->pending = __raw_readl(ldata->base + RTC_RIS);
	alarm->enabled = __raw_readl(ldata->base + RTC_IMSC);

	return 0;
}

static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
	struct pl031_local *ldata = dev_get_drvdata(dev);
	unsigned long time;

	rtc_tm_to_time(&alarm->time, &time);

	__raw_writel(time, ldata->base + RTC_MR);
	__raw_writel(!alarm->enabled, ldata->base + RTC_MIS);

	return 0;
}

static struct rtc_class_ops pl031_ops = {
	.open = pl031_open,
	.release = pl031_release,
	.ioctl = pl031_ioctl,
	.read_time = pl031_read_time,
	.set_time = pl031_set_time,
	.read_alarm = pl031_read_alarm,
	.set_alarm = pl031_set_alarm,
};

static int pl031_remove(struct amba_device *adev)
{
	struct pl031_local *ldata = dev_get_drvdata(&adev->dev);

	if (ldata) {
		dev_set_drvdata(&adev->dev, NULL);
		free_irq(adev->irq[0], ldata->rtc);
		rtc_device_unregister(ldata->rtc);
		iounmap(ldata->base);
		kfree(ldata);
	}

	return 0;
}

static int pl031_probe(struct amba_device *adev, void *id)
{
	int ret;
	struct pl031_local *ldata;


	ldata = kmalloc(sizeof(struct pl031_local), GFP_KERNEL);
	if (!ldata) {
		ret = -ENOMEM;
		goto out;
	}
	dev_set_drvdata(&adev->dev, ldata);

	ldata->base = ioremap(adev->res.start,
			      adev->res.end - adev->res.start + 1);
	if (!ldata->base) {
		ret = -ENOMEM;
		goto out_no_remap;
	}

	if (request_irq(adev->irq[0], pl031_interrupt, IRQF_DISABLED,
			"rtc-pl031", ldata->rtc)) {
		ret = -EIO;
		goto out_no_irq;
	}

	ldata->rtc = rtc_device_register("pl031", &adev->dev, &pl031_ops,
					 THIS_MODULE);
	if (IS_ERR(ldata->rtc)) {
		ret = PTR_ERR(ldata->rtc);
		goto out_no_rtc;
	}

	return 0;

out_no_rtc:
	free_irq(adev->irq[0], ldata->rtc);
out_no_irq:
	iounmap(ldata->base);
out_no_remap:
	dev_set_drvdata(&adev->dev, NULL);
	kfree(ldata);
out:
	return ret;
}

static struct amba_id pl031_ids[] __initdata = {
	{
		 .id = 0x00041031,
	 	.mask = 0x000fffff, },
	{0, 0},
};

static struct amba_driver pl031_driver = {
	.drv = {
		.name = "rtc-pl031",
	},
	.id_table = pl031_ids,
	.probe = pl031_probe,
	.remove = pl031_remove,
};

static int __init pl031_init(void)
{
	return amba_driver_register(&pl031_driver);
}

static void __exit pl031_exit(void)
{
	amba_driver_unregister(&pl031_driver);
}

module_init(pl031_init);
module_exit(pl031_exit);

MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net");
MODULE_DESCRIPTION("ARM AMBA PL031 RTC Driver");
MODULE_LICENSE("GPL");