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	struct rtc_device *rtc;
40};
41
42static int ep93xx_rtc_get_swcomp(struct device *dev, unsigned short *preload,
43				unsigned short *delete)
44{
45	struct ep93xx_rtc *ep93xx_rtc = dev_get_platdata(dev);
46	unsigned long comp;
47
48	comp = __raw_readl(ep93xx_rtc->mmio_base + EP93XX_RTC_SWCOMP);
49
50	if (preload)
51		*preload = (comp & EP93XX_RTC_SWCOMP_INT_MASK)
52				>> EP93XX_RTC_SWCOMP_INT_SHIFT;
53
54	if (delete)
55		*delete = (comp & EP93XX_RTC_SWCOMP_DEL_MASK)
56				>> EP93XX_RTC_SWCOMP_DEL_SHIFT;
57
58	return 0;
59}
60
61static int ep93xx_rtc_read_time(struct device *dev, struct rtc_time *tm)
62{
63	struct ep93xx_rtc *ep93xx_rtc = dev_get_platdata(dev);
64	unsigned long time;
65
66	 time = __raw_readl(ep93xx_rtc->mmio_base + EP93XX_RTC_DATA);
67
68	rtc_time_to_tm(time, tm);
69	return 0;
70}
71
72static int ep93xx_rtc_set_mmss(struct device *dev, unsigned long secs)
73{
74	struct ep93xx_rtc *ep93xx_rtc = dev_get_platdata(dev);
75
76	__raw_writel(secs + 1, ep93xx_rtc->mmio_base + EP93XX_RTC_LOAD);
77	return 0;
78}
79
80static int ep93xx_rtc_proc(struct device *dev, struct seq_file *seq)
81{
82	unsigned short preload, delete;
83
84	ep93xx_rtc_get_swcomp(dev, &preload, &delete);
85
86	seq_printf(seq, "preload\t\t: %d\n", preload);
87	seq_printf(seq, "delete\t\t: %d\n", delete);
88
89	return 0;
90}
91
92static const struct rtc_class_ops ep93xx_rtc_ops = {
93	.read_time	= ep93xx_rtc_read_time,
94	.set_mmss	= ep93xx_rtc_set_mmss,
95	.proc		= ep93xx_rtc_proc,
96};
97
98static ssize_t ep93xx_rtc_show_comp_preload(struct device *dev,
99			struct device_attribute *attr, char *buf)
100{
101	unsigned short preload;
102
103	ep93xx_rtc_get_swcomp(dev, &preload, NULL);
104
105	return sprintf(buf, "%d\n", preload);
106}
107static DEVICE_ATTR(comp_preload, S_IRUGO, ep93xx_rtc_show_comp_preload, NULL);
108
109static ssize_t ep93xx_rtc_show_comp_delete(struct device *dev,
110			struct device_attribute *attr, char *buf)
111{
112	unsigned short delete;
113
114	ep93xx_rtc_get_swcomp(dev, NULL, &delete);
115
116	return sprintf(buf, "%d\n", delete);
117}
118static DEVICE_ATTR(comp_delete, S_IRUGO, ep93xx_rtc_show_comp_delete, NULL);
119
120static struct attribute *ep93xx_rtc_attrs[] = {
121	&dev_attr_comp_preload.attr,
122	&dev_attr_comp_delete.attr,
123	NULL
124};
125
126static const struct attribute_group ep93xx_rtc_sysfs_files = {
127	.attrs	= ep93xx_rtc_attrs,
128};
129
130static int ep93xx_rtc_probe(struct platform_device *pdev)
131{
132	struct ep93xx_rtc *ep93xx_rtc;
133	struct resource *res;
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	ep93xx_rtc->mmio_base = devm_ioremap_resource(&pdev->dev, res);
142	if (IS_ERR(ep93xx_rtc->mmio_base))
143		return PTR_ERR(ep93xx_rtc->mmio_base);
144
145	pdev->dev.platform_data = ep93xx_rtc;
146	platform_set_drvdata(pdev, ep93xx_rtc);
147
148	ep93xx_rtc->rtc = devm_rtc_device_register(&pdev->dev,
149				pdev->name, &ep93xx_rtc_ops, THIS_MODULE);
150	if (IS_ERR(ep93xx_rtc->rtc)) {
151		err = PTR_ERR(ep93xx_rtc->rtc);
152		goto exit;
153	}
154
155	err = sysfs_create_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files);
156	if (err)
157		goto exit;
158
159	return 0;
160
161exit:
162	pdev->dev.platform_data = NULL;
163	return err;
164}
165
166static int ep93xx_rtc_remove(struct platform_device *pdev)
167{
168	sysfs_remove_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files);
169	pdev->dev.platform_data = NULL;
170
171	return 0;
172}
173
174static struct platform_driver ep93xx_rtc_driver = {
175	.driver		= {
176		.name	= "ep93xx-rtc",
177		.owner	= THIS_MODULE,
178	},
179	.probe		= ep93xx_rtc_probe,
180	.remove		= ep93xx_rtc_remove,
181};
182
183module_platform_driver(ep93xx_rtc_driver);
184
185MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
186MODULE_DESCRIPTION("EP93XX RTC driver");
187MODULE_LICENSE("GPL");
188MODULE_VERSION(DRV_VERSION);
189MODULE_ALIAS("platform:ep93xx-rtc");
190