tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * drivers/rtc/rtc-pl031.c
3 *
4 * Real Time Clock interface for ARM AMBA PrimeCell 031 RTC
5 *
6 * Author: Deepak Saxena <dsaxena@plexity.net>
7 *
8 * Copyright 2006 (c) MontaVista Software, Inc.
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
14 */
15#include <linux/module.h>
16#include <linux/rtc.h>
17#include <linux/init.h>
18#include <linux/interrupt.h>
19#include <linux/amba/bus.h>
20#include <linux/io.h>
21
22/*
23 * Register definitions
24 */
25#define RTC_DR 0x00 /* Data read register */
26#define RTC_MR 0x04 /* Match register */
27#define RTC_LR 0x08 /* Data load register */
28#define RTC_CR 0x0c /* Control register */
29#define RTC_IMSC 0x10 /* Interrupt mask and set register */
30#define RTC_RIS 0x14 /* Raw interrupt status register */
31#define RTC_MIS 0x18 /* Masked interrupt status register */
32#define RTC_ICR 0x1c /* Interrupt clear register */
33
34struct pl031_local {
35 struct rtc_device *rtc;
36 void __iomem *base;
37};
38
39static irqreturn_t pl031_interrupt(int irq, void *dev_id)
40{
41 struct rtc_device *rtc = dev_id;
42
43 rtc_update_irq(rtc, 1, RTC_AF);
44
45 return IRQ_HANDLED;
46}
47
48static int pl031_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
49{
50 struct pl031_local *ldata = dev_get_drvdata(dev);
51
52 switch (cmd) {
53 case RTC_AIE_OFF:
54 writel(1, ldata->base + RTC_MIS);
55 return 0;
56 case RTC_AIE_ON:
57 writel(0, ldata->base + RTC_MIS);
58 return 0;
59 }
60
61 return -ENOIOCTLCMD;
62}
63
64static int pl031_read_time(struct device *dev, struct rtc_time *tm)
65{
66 struct pl031_local *ldata = dev_get_drvdata(dev);
67
68 rtc_time_to_tm(readl(ldata->base + RTC_DR), tm);
69
70 return 0;
71}
72
73static int pl031_set_time(struct device *dev, struct rtc_time *tm)
74{
75 unsigned long time;
76 struct pl031_local *ldata = dev_get_drvdata(dev);
77
78 rtc_tm_to_time(tm, &time);
79 writel(time, ldata->base + RTC_LR);
80
81 return 0;
82}
83
84static int pl031_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
85{
86 struct pl031_local *ldata = dev_get_drvdata(dev);
87
88 rtc_time_to_tm(readl(ldata->base + RTC_MR), &alarm->time);
89 alarm->pending = readl(ldata->base + RTC_RIS);
90 alarm->enabled = readl(ldata->base + RTC_IMSC);
91
92 return 0;
93}
94
95static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
96{
97 struct pl031_local *ldata = dev_get_drvdata(dev);
98 unsigned long time;
99
100 rtc_tm_to_time(&alarm->time, &time);
101
102 writel(time, ldata->base + RTC_MR);
103 writel(!alarm->enabled, ldata->base + RTC_MIS);
104
105 return 0;
106}
107
108static const struct rtc_class_ops pl031_ops = {
109 .ioctl = pl031_ioctl,
110 .read_time = pl031_read_time,
111 .set_time = pl031_set_time,
112 .read_alarm = pl031_read_alarm,
113 .set_alarm = pl031_set_alarm,
114};
115
116static int pl031_remove(struct amba_device *adev)
117{
118 struct pl031_local *ldata = dev_get_drvdata(&adev->dev);
119
120 amba_set_drvdata(adev, NULL);
121 free_irq(adev->irq[0], ldata->rtc);
122 rtc_device_unregister(ldata->rtc);
123 iounmap(ldata->base);
124 kfree(ldata);
125 amba_release_regions(adev);
126
127 return 0;
128}
129
130static int pl031_probe(struct amba_device *adev, struct amba_id *id)
131{
132 int ret;
133 struct pl031_local *ldata;
134
135 ret = amba_request_regions(adev, NULL);
136 if (ret)
137 goto err_req;
138
139 ldata = kmalloc(sizeof(struct pl031_local), GFP_KERNEL);
140 if (!ldata) {
141 ret = -ENOMEM;
142 goto out;
143 }
144
145 ldata->base = ioremap(adev->res.start, resource_size(&adev->res));
146 if (!ldata->base) {
147 ret = -ENOMEM;
148 goto out_no_remap;
149 }
150
151 amba_set_drvdata(adev, ldata);
152
153 if (request_irq(adev->irq[0], pl031_interrupt, IRQF_DISABLED,
154 "rtc-pl031", ldata->rtc)) {
155 ret = -EIO;
156 goto out_no_irq;
157 }
158
159 ldata->rtc = rtc_device_register("pl031", &adev->dev, &pl031_ops,
160 THIS_MODULE);
161 if (IS_ERR(ldata->rtc)) {
162 ret = PTR_ERR(ldata->rtc);
163 goto out_no_rtc;
164 }
165
166 return 0;
167
168out_no_rtc:
169 free_irq(adev->irq[0], ldata->rtc);
170out_no_irq:
171 iounmap(ldata->base);
172 amba_set_drvdata(adev, NULL);
173out_no_remap:
174 kfree(ldata);
175out:
176 amba_release_regions(adev);
177err_req:
178 return ret;
179}
180
181static struct amba_id pl031_ids[] __initdata = {
182 {
183 .id = 0x00041031,
184 .mask = 0x000fffff,
185 },
186 {0, 0},
187};
188
189static struct amba_driver pl031_driver = {
190 .drv = {
191 .name = "rtc-pl031",
192 },
193 .id_table = pl031_ids,
194 .probe = pl031_probe,
195 .remove = pl031_remove,
196};
197
198static int __init pl031_init(void)
199{
200 return amba_driver_register(&pl031_driver);
201}
202
203static void __exit pl031_exit(void)
204{
205 amba_driver_unregister(&pl031_driver);
206}
207
208module_init(pl031_init);
209module_exit(pl031_exit);
210
211MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net");
212MODULE_DESCRIPTION("ARM AMBA PL031 RTC Driver");
213MODULE_LICENSE("GPL");