[PATCH] RTC subsystem: compact error messages
[linux-2.6.git] / drivers / rtc / rtc-ep93xx.c
1 /*
2  * A driver for the RTC embedded in the Cirrus Logic EP93XX processors
3  * Copyright (c) 2006 Tower Technologies
4  *
5  * Author: Alessandro Zummo <a.zummo@towertech.it>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11
12 #include <linux/module.h>
13 #include <linux/rtc.h>
14 #include <linux/platform_device.h>
15 #include <asm/hardware.h>
16
17 #define EP93XX_RTC_REG(x)       (EP93XX_RTC_BASE + (x))
18 #define EP93XX_RTC_DATA         EP93XX_RTC_REG(0x0000)
19 #define EP93XX_RTC_LOAD         EP93XX_RTC_REG(0x000C)
20 #define EP93XX_RTC_SWCOMP       EP93XX_RTC_REG(0x0108)
21
22 #define DRV_VERSION "0.2"
23
24 static int ep93xx_get_swcomp(struct device *dev, unsigned short *preload,
25                                 unsigned short *delete)
26 {
27         unsigned short comp = __raw_readl(EP93XX_RTC_SWCOMP);
28
29         if (preload)
30                 *preload = comp & 0xffff;
31
32         if (delete)
33                 *delete = (comp >> 16) & 0x1f;
34
35         return 0;
36 }
37
38 static int ep93xx_rtc_read_time(struct device *dev, struct rtc_time *tm)
39 {
40         unsigned long time = __raw_readl(EP93XX_RTC_DATA);
41
42         rtc_time_to_tm(time, tm);
43         return 0;
44 }
45
46 static int ep93xx_rtc_set_mmss(struct device *dev, unsigned long secs)
47 {
48         __raw_writel(secs + 1, EP93XX_RTC_LOAD);
49         return 0;
50 }
51
52 static int ep93xx_rtc_set_time(struct device *dev, struct rtc_time *tm)
53 {
54         int err;
55         unsigned long secs;
56
57         err = rtc_tm_to_time(tm, &secs);
58         if (err != 0)
59                 return err;
60
61         return ep93xx_rtc_set_mmss(dev, secs);
62 }
63
64 static int ep93xx_rtc_proc(struct device *dev, struct seq_file *seq)
65 {
66         unsigned short preload, delete;
67
68         ep93xx_get_swcomp(dev, &preload, &delete);
69
70         seq_printf(seq, "preload\t\t: %d\n", preload);
71         seq_printf(seq, "delete\t\t: %d\n", delete);
72
73         return 0;
74 }
75
76 static struct rtc_class_ops ep93xx_rtc_ops = {
77         .read_time      = ep93xx_rtc_read_time,
78         .set_time       = ep93xx_rtc_set_time,
79         .set_mmss       = ep93xx_rtc_set_mmss,
80         .proc           = ep93xx_rtc_proc,
81 };
82
83 static ssize_t ep93xx_sysfs_show_comp_preload(struct device *dev,
84                         struct device_attribute *attr, char *buf)
85 {
86         unsigned short preload;
87
88         ep93xx_get_swcomp(dev, &preload, NULL);
89
90         return sprintf(buf, "%d\n", preload);
91 }
92 static DEVICE_ATTR(comp_preload, S_IRUGO, ep93xx_sysfs_show_comp_preload, NULL);
93
94 static ssize_t ep93xx_sysfs_show_comp_delete(struct device *dev,
95                         struct device_attribute *attr, char *buf)
96 {
97         unsigned short delete;
98
99         ep93xx_get_swcomp(dev, NULL, &delete);
100
101         return sprintf(buf, "%d\n", delete);
102 }
103 static DEVICE_ATTR(comp_delete, S_IRUGO, ep93xx_sysfs_show_comp_delete, NULL);
104
105
106 static int __devinit ep93xx_rtc_probe(struct platform_device *dev)
107 {
108         struct rtc_device *rtc = rtc_device_register("ep93xx",
109                                 &dev->dev, &ep93xx_rtc_ops, THIS_MODULE);
110
111         if (IS_ERR(rtc)) {
112                 return PTR_ERR(rtc);
113         }
114
115         platform_set_drvdata(dev, rtc);
116
117         device_create_file(&dev->dev, &dev_attr_comp_preload);
118         device_create_file(&dev->dev, &dev_attr_comp_delete);
119
120         return 0;
121 }
122
123 static int __devexit ep93xx_rtc_remove(struct platform_device *dev)
124 {
125         struct rtc_device *rtc = platform_get_drvdata(dev);
126
127         if (rtc)
128                 rtc_device_unregister(rtc);
129
130         platform_set_drvdata(dev, NULL);
131
132         return 0;
133 }
134
135 static struct platform_driver ep93xx_rtc_platform_driver = {
136         .driver         = {
137                 .name   = "ep93xx-rtc",
138                 .owner  = THIS_MODULE,
139         },
140         .probe          = ep93xx_rtc_probe,
141         .remove         = __devexit_p(ep93xx_rtc_remove),
142 };
143
144 static int __init ep93xx_rtc_init(void)
145 {
146         return platform_driver_register(&ep93xx_rtc_platform_driver);
147 }
148
149 static void __exit ep93xx_rtc_exit(void)
150 {
151         platform_driver_unregister(&ep93xx_rtc_platform_driver);
152 }
153
154 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
155 MODULE_DESCRIPTION("EP93XX RTC driver");
156 MODULE_LICENSE("GPL");
157 MODULE_VERSION(DRV_VERSION);
158
159 module_init(ep93xx_rtc_init);
160 module_exit(ep93xx_rtc_exit);