[go: nahoru, domu]
1/*
2 *  linux/drivers/rtc/rtc-pl030.c
3 *
4 *  Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10#include <linux/module.h>
11#include <linux/rtc.h>
12#include <linux/init.h>
13#include <linux/interrupt.h>
14#include <linux/amba/bus.h>
15#include <linux/io.h>
16#include <linux/slab.h>
17
18#define RTC_DR		(0)
19#define RTC_MR		(4)
20#define RTC_STAT	(8)
21#define RTC_EOI		(8)
22#define RTC_LR		(12)
23#define RTC_CR		(16)
24#define RTC_CR_MIE	(1 << 0)
25
26struct pl030_rtc {
27	struct rtc_device	*rtc;
28	void __iomem		*base;
29};
30
31static irqreturn_t pl030_interrupt(int irq, void *dev_id)
32{
33	struct pl030_rtc *rtc = dev_id;
34	writel(0, rtc->base + RTC_EOI);
35	return IRQ_HANDLED;
36}
37
38static int pl030_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
39{
40	struct pl030_rtc *rtc = dev_get_drvdata(dev);
41
42	rtc_time_to_tm(readl(rtc->base + RTC_MR), &alrm->time);
43	return 0;
44}
45
46static int pl030_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
47{
48	struct pl030_rtc *rtc = dev_get_drvdata(dev);
49	unsigned long time;
50	int ret;
51
52	/*
53	 * At the moment, we can only deal with non-wildcarded alarm times.
54	 */
55	ret = rtc_valid_tm(&alrm->time);
56	if (ret == 0)
57		ret = rtc_tm_to_time(&alrm->time, &time);
58	if (ret == 0)
59		writel(time, rtc->base + RTC_MR);
60	return ret;
61}
62
63static int pl030_read_time(struct device *dev, struct rtc_time *tm)
64{
65	struct pl030_rtc *rtc = dev_get_drvdata(dev);
66
67	rtc_time_to_tm(readl(rtc->base + RTC_DR), tm);
68
69	return 0;
70}
71
72/*
73 * Set the RTC time.  Unfortunately, we can't accurately set
74 * the point at which the counter updates.
75 *
76 * Also, since RTC_LR is transferred to RTC_CR on next rising
77 * edge of the 1Hz clock, we must write the time one second
78 * in advance.
79 */
80static int pl030_set_time(struct device *dev, struct rtc_time *tm)
81{
82	struct pl030_rtc *rtc = dev_get_drvdata(dev);
83	unsigned long time;
84	int ret;
85
86	ret = rtc_tm_to_time(tm, &time);
87	if (ret == 0)
88		writel(time + 1, rtc->base + RTC_LR);
89
90	return ret;
91}
92
93static const struct rtc_class_ops pl030_ops = {
94	.read_time	= pl030_read_time,
95	.set_time	= pl030_set_time,
96	.read_alarm	= pl030_read_alarm,
97	.set_alarm	= pl030_set_alarm,
98};
99
100static int pl030_probe(struct amba_device *dev, const struct amba_id *id)
101{
102	struct pl030_rtc *rtc;
103	int ret;
104
105	ret = amba_request_regions(dev, NULL);
106	if (ret)
107		goto err_req;
108
109	rtc = devm_kzalloc(&dev->dev, sizeof(*rtc), GFP_KERNEL);
110	if (!rtc) {
111		ret = -ENOMEM;
112		goto err_rtc;
113	}
114
115	rtc->base = ioremap(dev->res.start, resource_size(&dev->res));
116	if (!rtc->base) {
117		ret = -ENOMEM;
118		goto err_rtc;
119	}
120
121	__raw_writel(0, rtc->base + RTC_CR);
122	__raw_writel(0, rtc->base + RTC_EOI);
123
124	amba_set_drvdata(dev, rtc);
125
126	ret = request_irq(dev->irq[0], pl030_interrupt, 0,
127			  "rtc-pl030", rtc);
128	if (ret)
129		goto err_irq;
130
131	rtc->rtc = rtc_device_register("pl030", &dev->dev, &pl030_ops,
132				       THIS_MODULE);
133	if (IS_ERR(rtc->rtc)) {
134		ret = PTR_ERR(rtc->rtc);
135		goto err_reg;
136	}
137
138	return 0;
139
140 err_reg:
141	free_irq(dev->irq[0], rtc);
142 err_irq:
143	iounmap(rtc->base);
144 err_rtc:
145	amba_release_regions(dev);
146 err_req:
147	return ret;
148}
149
150static int pl030_remove(struct amba_device *dev)
151{
152	struct pl030_rtc *rtc = amba_get_drvdata(dev);
153
154	writel(0, rtc->base + RTC_CR);
155
156	free_irq(dev->irq[0], rtc);
157	rtc_device_unregister(rtc->rtc);
158	iounmap(rtc->base);
159	amba_release_regions(dev);
160
161	return 0;
162}
163
164static struct amba_id pl030_ids[] = {
165	{
166		.id	= 0x00041030,
167		.mask	= 0x000fffff,
168	},
169	{ 0, 0 },
170};
171
172MODULE_DEVICE_TABLE(amba, pl030_ids);
173
174static struct amba_driver pl030_driver = {
175	.drv		= {
176		.name	= "rtc-pl030",
177	},
178	.probe		= pl030_probe,
179	.remove		= pl030_remove,
180	.id_table	= pl030_ids,
181};
182
183module_amba_driver(pl030_driver);
184
185MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
186MODULE_DESCRIPTION("ARM AMBA PL030 RTC Driver");
187MODULE_LICENSE("GPL");
188