tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 <linux/io.h>
16
17#define EP93XX_RTC_DATA 0x000
18#define EP93XX_RTC_MATCH 0x004
19#define EP93XX_RTC_STATUS 0x008
20#define EP93XX_RTC_STATUS_INTR (1<<0)
21#define EP93XX_RTC_LOAD 0x00C
22#define EP93XX_RTC_CONTROL 0x010
23#define EP93XX_RTC_CONTROL_MIE (1<<0)
24#define EP93XX_RTC_SWCOMP 0x108
25#define EP93XX_RTC_SWCOMP_DEL_MASK 0x001f0000
26#define EP93XX_RTC_SWCOMP_DEL_SHIFT 16
27#define EP93XX_RTC_SWCOMP_INT_MASK 0x0000ffff
28#define EP93XX_RTC_SWCOMP_INT_SHIFT 0
29
30#define DRV_VERSION "0.3"
31
32/*
33 * struct device dev.platform_data is used to store our private data
34 * because struct rtc_device does not have a variable to hold it.
35 */
36struct ep93xx_rtc {
37 void __iomem *mmio_base;
38};
39
40static int ep93xx_rtc_get_swcomp(struct device *dev, unsigned short *preload,
41 unsigned short *delete)
42{
43 struct ep93xx_rtc *ep93xx_rtc = dev->platform_data;
44 unsigned long comp;
45
46 comp = __raw_readl(ep93xx_rtc->mmio_base + EP93XX_RTC_SWCOMP);
47
48 if (preload)
49 *preload = (comp & EP93XX_RTC_SWCOMP_INT_MASK)
50 >> EP93XX_RTC_SWCOMP_INT_SHIFT;
51
52 if (delete)
53 *delete = (comp & EP93XX_RTC_SWCOMP_DEL_MASK)
54 >> EP93XX_RTC_SWCOMP_DEL_SHIFT;
55
56 return 0;
57}
58
59static int ep93xx_rtc_read_time(struct device *dev, struct rtc_time *tm)
60{
61 struct ep93xx_rtc *ep93xx_rtc = dev->platform_data;
62 unsigned long time;
63
64 time = __raw_readl(ep93xx_rtc->mmio_base + EP93XX_RTC_DATA);
65
66 rtc_time_to_tm(time, tm);
67 return 0;
68}
69
70static int ep93xx_rtc_set_mmss(struct device *dev, unsigned long secs)
71{
72 struct ep93xx_rtc *ep93xx_rtc = dev->platform_data;
73
74 __raw_writel(secs + 1, ep93xx_rtc->mmio_base + EP93XX_RTC_LOAD);
75 return 0;
76}
77
78static int ep93xx_rtc_proc(struct device *dev, struct seq_file *seq)
79{
80 unsigned short preload, delete;
81
82 ep93xx_rtc_get_swcomp(dev, &preload, &delete);
83
84 seq_printf(seq, "preload\t\t: %d\n", preload);
85 seq_printf(seq, "delete\t\t: %d\n", delete);
86
87 return 0;
88}
89
90static const struct rtc_class_ops ep93xx_rtc_ops = {
91 .read_time = ep93xx_rtc_read_time,
92 .set_mmss = ep93xx_rtc_set_mmss,
93 .proc = ep93xx_rtc_proc,
94};
95
96static ssize_t ep93xx_rtc_show_comp_preload(struct device *dev,
97 struct device_attribute *attr, char *buf)
98{
99 unsigned short preload;
100
101 ep93xx_rtc_get_swcomp(dev, &preload, NULL);
102
103 return sprintf(buf, "%d\n", preload);
104}
105static DEVICE_ATTR(comp_preload, S_IRUGO, ep93xx_rtc_show_comp_preload, NULL);
106
107static ssize_t ep93xx_rtc_show_comp_delete(struct device *dev,
108 struct device_attribute *attr, char *buf)
109{
110 unsigned short delete;
111
112 ep93xx_rtc_get_swcomp(dev, NULL, &delete);
113
114 return sprintf(buf, "%d\n", delete);
115}
116static DEVICE_ATTR(comp_delete, S_IRUGO, ep93xx_rtc_show_comp_delete, NULL);
117
118static struct attribute *ep93xx_rtc_attrs[] = {
119 &dev_attr_comp_preload.attr,
120 &dev_attr_comp_delete.attr,
121 NULL
122};
123
124static const struct attribute_group ep93xx_rtc_sysfs_files = {
125 .attrs = ep93xx_rtc_attrs,
126};
127
128static int __init ep93xx_rtc_probe(struct platform_device *pdev)
129{
130 struct ep93xx_rtc *ep93xx_rtc;
131 struct resource *res;
132 struct rtc_device *rtc;
133 int err;
134
135 ep93xx_rtc = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_rtc), GFP_KERNEL);
136 if (!ep93xx_rtc)
137 return -ENOMEM;
138
139 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
140 if (!res)
141 return -ENXIO;
142
143 if (!devm_request_mem_region(&pdev->dev, res->start,
144 resource_size(res), pdev->name))
145 return -EBUSY;
146
147 ep93xx_rtc->mmio_base = devm_ioremap(&pdev->dev, res->start,
148 resource_size(res));
149 if (!ep93xx_rtc->mmio_base)
150 return -ENXIO;
151
152 pdev->dev.platform_data = ep93xx_rtc;
153
154 rtc = rtc_device_register(pdev->name,
155 &pdev->dev, &ep93xx_rtc_ops, THIS_MODULE);
156 if (IS_ERR(rtc)) {
157 err = PTR_ERR(rtc);
158 goto exit;
159 }
160
161 platform_set_drvdata(pdev, rtc);
162
163 err = sysfs_create_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files);
164 if (err)
165 goto fail;
166
167 return 0;
168
169fail:
170 platform_set_drvdata(pdev, NULL);
171 rtc_device_unregister(rtc);
172exit:
173 pdev->dev.platform_data = NULL;
174 return err;
175}
176
177static int __exit ep93xx_rtc_remove(struct platform_device *pdev)
178{
179 struct rtc_device *rtc = platform_get_drvdata(pdev);
180
181 sysfs_remove_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files);
182 platform_set_drvdata(pdev, NULL);
183 rtc_device_unregister(rtc);
184 pdev->dev.platform_data = NULL;
185
186 return 0;
187}
188
189/* work with hotplug and coldplug */
190MODULE_ALIAS("platform:ep93xx-rtc");
191
192static struct platform_driver ep93xx_rtc_driver = {
193 .driver = {
194 .name = "ep93xx-rtc",
195 .owner = THIS_MODULE,
196 },
197 .remove = __exit_p(ep93xx_rtc_remove),
198};
199
200static int __init ep93xx_rtc_init(void)
201{
202 return platform_driver_probe(&ep93xx_rtc_driver, ep93xx_rtc_probe);
203}
204
205static void __exit ep93xx_rtc_exit(void)
206{
207 platform_driver_unregister(&ep93xx_rtc_driver);
208}
209
210MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
211MODULE_DESCRIPTION("EP93XX RTC driver");
212MODULE_LICENSE("GPL");
213MODULE_VERSION(DRV_VERSION);
214
215module_init(ep93xx_rtc_init);
216module_exit(ep93xx_rtc_exit);