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/*
32 * struct device dev.platform_data is used to store our private data
33 * because struct rtc_device does not have a variable to hold it.
34 */
35struct ep93xx_rtc {
36 void __iomem *mmio_base;
37 struct rtc_device *rtc;
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_get_platdata(dev);
44 unsigned long comp;
45
46 comp = 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_get_platdata(dev);
62 unsigned long time;
63
64 time = 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_get_platdata(dev);
73
74 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 ep93xx_rtc_probe(struct platform_device *pdev)
129{
130 struct ep93xx_rtc *ep93xx_rtc;
131 struct resource *res;
132 int err;
133
134 ep93xx_rtc = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_rtc), GFP_KERNEL);
135 if (!ep93xx_rtc)
136 return -ENOMEM;
137
138 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
139 ep93xx_rtc->mmio_base = devm_ioremap_resource(&pdev->dev, res);
140 if (IS_ERR(ep93xx_rtc->mmio_base))
141 return PTR_ERR(ep93xx_rtc->mmio_base);
142
143 pdev->dev.platform_data = ep93xx_rtc;
144 platform_set_drvdata(pdev, ep93xx_rtc);
145
146 ep93xx_rtc->rtc = devm_rtc_device_register(&pdev->dev,
147 pdev->name, &ep93xx_rtc_ops, THIS_MODULE);
148 if (IS_ERR(ep93xx_rtc->rtc)) {
149 err = PTR_ERR(ep93xx_rtc->rtc);
150 goto exit;
151 }
152
153 err = sysfs_create_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files);
154 if (err)
155 goto exit;
156
157 return 0;
158
159exit:
160 pdev->dev.platform_data = NULL;
161 return err;
162}
163
164static int ep93xx_rtc_remove(struct platform_device *pdev)
165{
166 sysfs_remove_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files);
167 pdev->dev.platform_data = NULL;
168
169 return 0;
170}
171
172static struct platform_driver ep93xx_rtc_driver = {
173 .driver = {
174 .name = "ep93xx-rtc",
175 },
176 .probe = ep93xx_rtc_probe,
177 .remove = ep93xx_rtc_remove,
178};
179
180module_platform_driver(ep93xx_rtc_driver);
181
182MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
183MODULE_DESCRIPTION("EP93XX RTC driver");
184MODULE_LICENSE("GPL");
185MODULE_ALIAS("platform:ep93xx-rtc");