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#include <linux/gfp.h>
17
18#define EP93XX_RTC_DATA 0x000
19#define EP93XX_RTC_MATCH 0x004
20#define EP93XX_RTC_STATUS 0x008
21#define EP93XX_RTC_STATUS_INTR (1<<0)
22#define EP93XX_RTC_LOAD 0x00C
23#define EP93XX_RTC_CONTROL 0x010
24#define EP93XX_RTC_CONTROL_MIE (1<<0)
25#define EP93XX_RTC_SWCOMP 0x108
26#define EP93XX_RTC_SWCOMP_DEL_MASK 0x001f0000
27#define EP93XX_RTC_SWCOMP_DEL_SHIFT 16
28#define EP93XX_RTC_SWCOMP_INT_MASK 0x0000ffff
29#define EP93XX_RTC_SWCOMP_INT_SHIFT 0
30
31#define DRV_VERSION "0.3"
32
33/*
34 * struct device dev.platform_data is used to store our private data
35 * because struct rtc_device does not have a variable to hold it.
36 */
37struct ep93xx_rtc {
38 void __iomem *mmio_base;
39};
40
41static int ep93xx_rtc_get_swcomp(struct device *dev, unsigned short *preload,
42 unsigned short *delete)
43{
44 struct ep93xx_rtc *ep93xx_rtc = dev->platform_data;
45 unsigned long comp;
46
47 comp = __raw_readl(ep93xx_rtc->mmio_base + EP93XX_RTC_SWCOMP);
48
49 if (preload)
50 *preload = (comp & EP93XX_RTC_SWCOMP_INT_MASK)
51 >> EP93XX_RTC_SWCOMP_INT_SHIFT;
52
53 if (delete)
54 *delete = (comp & EP93XX_RTC_SWCOMP_DEL_MASK)
55 >> EP93XX_RTC_SWCOMP_DEL_SHIFT;
56
57 return 0;
58}
59
60static int ep93xx_rtc_read_time(struct device *dev, struct rtc_time *tm)
61{
62 struct ep93xx_rtc *ep93xx_rtc = dev->platform_data;
63 unsigned long time;
64
65 time = __raw_readl(ep93xx_rtc->mmio_base + EP93XX_RTC_DATA);
66
67 rtc_time_to_tm(time, tm);
68 return 0;
69}
70
71static int ep93xx_rtc_set_mmss(struct device *dev, unsigned long secs)
72{
73 struct ep93xx_rtc *ep93xx_rtc = dev->platform_data;
74
75 __raw_writel(secs + 1, ep93xx_rtc->mmio_base + EP93XX_RTC_LOAD);
76 return 0;
77}
78
79static int ep93xx_rtc_proc(struct device *dev, struct seq_file *seq)
80{
81 unsigned short preload, delete;
82
83 ep93xx_rtc_get_swcomp(dev, &preload, &delete);
84
85 seq_printf(seq, "preload\t\t: %d\n", preload);
86 seq_printf(seq, "delete\t\t: %d\n", delete);
87
88 return 0;
89}
90
91static const struct rtc_class_ops ep93xx_rtc_ops = {
92 .read_time = ep93xx_rtc_read_time,
93 .set_mmss = ep93xx_rtc_set_mmss,
94 .proc = ep93xx_rtc_proc,
95};
96
97static ssize_t ep93xx_rtc_show_comp_preload(struct device *dev,
98 struct device_attribute *attr, char *buf)
99{
100 unsigned short preload;
101
102 ep93xx_rtc_get_swcomp(dev, &preload, NULL);
103
104 return sprintf(buf, "%d\n", preload);
105}
106static DEVICE_ATTR(comp_preload, S_IRUGO, ep93xx_rtc_show_comp_preload, NULL);
107
108static ssize_t ep93xx_rtc_show_comp_delete(struct device *dev,
109 struct device_attribute *attr, char *buf)
110{
111 unsigned short delete;
112
113 ep93xx_rtc_get_swcomp(dev, NULL, &delete);
114
115 return sprintf(buf, "%d\n", delete);
116}
117static DEVICE_ATTR(comp_delete, S_IRUGO, ep93xx_rtc_show_comp_delete, NULL);
118
119static struct attribute *ep93xx_rtc_attrs[] = {
120 &dev_attr_comp_preload.attr,
121 &dev_attr_comp_delete.attr,
122 NULL
123};
124
125static const struct attribute_group ep93xx_rtc_sysfs_files = {
126 .attrs = ep93xx_rtc_attrs,
127};
128
129static int __init ep93xx_rtc_probe(struct platform_device *pdev)
130{
131 struct ep93xx_rtc *ep93xx_rtc;
132 struct resource *res;
133 struct rtc_device *rtc;
134 int err;
135
136 ep93xx_rtc = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_rtc), GFP_KERNEL);
137 if (!ep93xx_rtc)
138 return -ENOMEM;
139
140 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
141 if (!res)
142 return -ENXIO;
143
144 if (!devm_request_mem_region(&pdev->dev, res->start,
145 resource_size(res), pdev->name))
146 return -EBUSY;
147
148 ep93xx_rtc->mmio_base = devm_ioremap(&pdev->dev, res->start,
149 resource_size(res));
150 if (!ep93xx_rtc->mmio_base)
151 return -ENXIO;
152
153 pdev->dev.platform_data = ep93xx_rtc;
154
155 rtc = rtc_device_register(pdev->name,
156 &pdev->dev, &ep93xx_rtc_ops, THIS_MODULE);
157 if (IS_ERR(rtc)) {
158 err = PTR_ERR(rtc);
159 goto exit;
160 }
161
162 platform_set_drvdata(pdev, rtc);
163
164 err = sysfs_create_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files);
165 if (err)
166 goto fail;
167
168 return 0;
169
170fail:
171 platform_set_drvdata(pdev, NULL);
172 rtc_device_unregister(rtc);
173exit:
174 pdev->dev.platform_data = NULL;
175 return err;
176}
177
178static int __exit ep93xx_rtc_remove(struct platform_device *pdev)
179{
180 struct rtc_device *rtc = platform_get_drvdata(pdev);
181
182 sysfs_remove_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files);
183 platform_set_drvdata(pdev, NULL);
184 rtc_device_unregister(rtc);
185 pdev->dev.platform_data = NULL;
186
187 return 0;
188}
189
190/* work with hotplug and coldplug */
191MODULE_ALIAS("platform:ep93xx-rtc");
192
193static struct platform_driver ep93xx_rtc_driver = {
194 .driver = {
195 .name = "ep93xx-rtc",
196 .owner = THIS_MODULE,
197 },
198 .remove = __exit_p(ep93xx_rtc_remove),
199};
200
201static int __init ep93xx_rtc_init(void)
202{
203 return platform_driver_probe(&ep93xx_rtc_driver, ep93xx_rtc_probe);
204}
205
206static void __exit ep93xx_rtc_exit(void)
207{
208 platform_driver_unregister(&ep93xx_rtc_driver);
209}
210
211MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
212MODULE_DESCRIPTION("EP93XX RTC driver");
213MODULE_LICENSE("GPL");
214MODULE_VERSION(DRV_VERSION);
215
216module_init(ep93xx_rtc_init);
217module_exit(ep93xx_rtc_exit);