[deliverable/linux.git] / drivers / rtc / rtc-m48t35.c

/*
 * Driver for the SGS-Thomson M48T35 Timekeeper RAM chip
 *
 * Copyright (C) 2000 Silicon Graphics, Inc.
 * Written by Ulf Carlsson (ulfc@engr.sgi.com)
 *
 * Copyright (C) 2008 Thomas Bogendoerfer
 *
 * Based on code written by Paul Gortmaker.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 */

#include <linux/module.h>
#include <linux/rtc.h>
#include <linux/platform_device.h>
#include <linux/bcd.h>

#define DRV_VERSION		"1.0"

struct m48t35_rtc {
	u8	pad[0x7ff8];    /* starts at 0x7ff8 */
	u8	control;
	u8	sec;
	u8	min;
	u8	hour;
	u8	day;
	u8	date;
	u8	month;
	u8	year;
};

#define M48T35_RTC_SET		0x80
#define M48T35_RTC_READ		0x40

struct m48t35_priv {
	struct rtc_device *rtc;
	struct m48t35_rtc __iomem *reg;
	size_t size;
	unsigned long baseaddr;
	spinlock_t lock;
};

static int m48t35_read_time(struct device *dev, struct rtc_time *tm)
{
	struct m48t35_priv *priv = dev_get_drvdata(dev);
	u8 control;

	/*
	 * Only the values that we read from the RTC are set. We leave
	 * tm_wday, tm_yday and tm_isdst untouched. Even though the
	 * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
	 * by the RTC when initially set to a non-zero value.
	 */
	spin_lock_irq(&priv->lock);
	control = readb(&priv->reg->control);
	writeb(control | M48T35_RTC_READ, &priv->reg->control);
	tm->tm_sec = readb(&priv->reg->sec);
	tm->tm_min = readb(&priv->reg->min);
	tm->tm_hour = readb(&priv->reg->hour);
	tm->tm_mday = readb(&priv->reg->date);
	tm->tm_mon = readb(&priv->reg->month);
	tm->tm_year = readb(&priv->reg->year);
	writeb(control, &priv->reg->control);
	spin_unlock_irq(&priv->lock);

	tm->tm_sec = bcd2bin(tm->tm_sec);
	tm->tm_min = bcd2bin(tm->tm_min);
	tm->tm_hour = bcd2bin(tm->tm_hour);
	tm->tm_mday = bcd2bin(tm->tm_mday);
	tm->tm_mon = bcd2bin(tm->tm_mon);
	tm->tm_year = bcd2bin(tm->tm_year);

	/*
	 * Account for differences between how the RTC uses the values
	 * and how they are defined in a struct rtc_time;
	 */
	tm->tm_year += 70;
	if (tm->tm_year <= 69)
		tm->tm_year += 100;

	tm->tm_mon--;
	return rtc_valid_tm(tm);
}

static int m48t35_set_time(struct device *dev, struct rtc_time *tm)
{
	struct m48t35_priv *priv = dev_get_drvdata(dev);
	unsigned char mon, day, hrs, min, sec;
	unsigned int yrs;
	u8 control;

	yrs = tm->tm_year + 1900;
	mon = tm->tm_mon + 1;   /* tm_mon starts at zero */
	day = tm->tm_mday;
	hrs = tm->tm_hour;
	min = tm->tm_min;
	sec = tm->tm_sec;

	if (yrs < 1970)
		return -EINVAL;

	yrs -= 1970;
	if (yrs > 255)    /* They are unsigned */
		return -EINVAL;

	if (yrs > 169)
		return -EINVAL;

	if (yrs >= 100)
		yrs -= 100;

	sec = bin2bcd(sec);
	min = bin2bcd(min);
	hrs = bin2bcd(hrs);
	day = bin2bcd(day);
	mon = bin2bcd(mon);
	yrs = bin2bcd(yrs);

	spin_lock_irq(&priv->lock);
	control = readb(&priv->reg->control);
	writeb(control | M48T35_RTC_SET, &priv->reg->control);
	writeb(yrs, &priv->reg->year);
	writeb(mon, &priv->reg->month);
	writeb(day, &priv->reg->date);
	writeb(hrs, &priv->reg->hour);
	writeb(min, &priv->reg->min);
	writeb(sec, &priv->reg->sec);
	writeb(control, &priv->reg->control);
	spin_unlock_irq(&priv->lock);
	return 0;
}

static const struct rtc_class_ops m48t35_ops = {
	.read_time	= m48t35_read_time,
	.set_time	= m48t35_set_time,
};

static int __devinit m48t35_probe(struct platform_device *pdev)
{
	struct rtc_device *rtc;
	struct resource *res;
	struct m48t35_priv *priv;
	int ret = 0;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res)
		return -ENODEV;
	priv = kzalloc(sizeof(struct m48t35_priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	priv->size = res->end - res->start + 1;
	/*
	 * kludge: remove the #ifndef after ioc3 resource
	 * conflicts are resolved
	 */
#ifndef CONFIG_SGI_IP27
	if (!request_mem_region(res->start, priv->size, pdev->name)) {
		ret = -EBUSY;
		goto out;
	}
#endif
	priv->baseaddr = res->start;
	priv->reg = ioremap(priv->baseaddr, priv->size);
	if (!priv->reg) {
		ret = -ENOMEM;
		goto out;
	}
	spin_lock_init(&priv->lock);
	rtc = rtc_device_register("m48t35", &pdev->dev,
				  &m48t35_ops, THIS_MODULE);
	if (IS_ERR(rtc)) {
		ret = PTR_ERR(rtc);
		goto out;
	}
	priv->rtc = rtc;
	platform_set_drvdata(pdev, priv);
	return 0;

out:
	if (priv->rtc)
		rtc_device_unregister(priv->rtc);
	if (priv->reg)
		iounmap(priv->reg);
	if (priv->baseaddr)
		release_mem_region(priv->baseaddr, priv->size);
	kfree(priv);
	return ret;
}

static int __devexit m48t35_remove(struct platform_device *pdev)
{
	struct m48t35_priv *priv = platform_get_drvdata(pdev);

	rtc_device_unregister(priv->rtc);
	iounmap(priv->reg);
#ifndef CONFIG_SGI_IP27
	release_mem_region(priv->baseaddr, priv->size);
#endif
	kfree(priv);
	return 0;
}

static struct platform_driver m48t35_platform_driver = {
	.driver		= {
		.name	= "rtc-m48t35",
		.owner	= THIS_MODULE,
	},
	.probe		= m48t35_probe,
	.remove		= __devexit_p(m48t35_remove),
};

static int __init m48t35_init(void)
{
	return platform_driver_register(&m48t35_platform_driver);
}

static void __exit m48t35_exit(void)
{
	platform_driver_unregister(&m48t35_platform_driver);
}

MODULE_AUTHOR("Thomas Bogendoerfer <tsbogend@alpha.franken.de>");
MODULE_DESCRIPTION("M48T35 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
MODULE_ALIAS("platform:rtc-m48t35");

module_init(m48t35_init);
module_exit(m48t35_exit);
Commit	Line	Data
d1dbd82e TB	1	/*
	2	* Driver for the SGS-Thomson M48T35 Timekeeper RAM chip
	3	*
	4	* Copyright (C) 2000 Silicon Graphics, Inc.
	5	* Written by Ulf Carlsson (ulfc@engr.sgi.com)
	6	*
	7	* Copyright (C) 2008 Thomas Bogendoerfer
	8	*
	9	* Based on code written by Paul Gortmaker.
	10	*
	11	* This program is free software; you can redistribute it and/or modify it
	12	* under the terms of the GNU General Public License as published by the
	13	* Free Software Foundation; either version 2 of the License, or (at your
	14	* option) any later version.
	15	*/
	16
	17	#include <linux/module.h>
	18	#include <linux/rtc.h>
	19	#include <linux/platform_device.h>
	20	#include <linux/bcd.h>
	21
	22	#define DRV_VERSION "1.0"
	23
	24	struct m48t35_rtc {
	25	u8 pad[0x7ff8]; /* starts at 0x7ff8 */
	26	u8 control;
	27	u8 sec;
	28	u8 min;
	29	u8 hour;
	30	u8 day;
	31	u8 date;
	32	u8 month;
	33	u8 year;
	34	};
	35
	36	#define M48T35_RTC_SET 0x80
	37	#define M48T35_RTC_READ 0x40
	38
	39	struct m48t35_priv {
	40	struct rtc_device *rtc;
	41	struct m48t35_rtc __iomem *reg;
	42	size_t size;
	43	unsigned long baseaddr;
	44	spinlock_t lock;
	45	};
	46
	47	static int m48t35_read_time(struct device dev, struct rtc_time tm)
	48	{
	49	struct m48t35_priv *priv = dev_get_drvdata(dev);
	50	u8 control;
	51
	52	/*
	53	* Only the values that we read from the RTC are set. We leave
	54	* tm_wday, tm_yday and tm_isdst untouched. Even though the
	55	* RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
	56	* by the RTC when initially set to a non-zero value.
	57	*/
	58	spin_lock_irq(&priv->lock);
	59	control = readb(&priv->reg->control);
	60	writeb(control \| M48T35_RTC_READ, &priv->reg->control);
	61	tm->tm_sec = readb(&priv->reg->sec);
	62	tm->tm_min = readb(&priv->reg->min);
	63	tm->tm_hour = readb(&priv->reg->hour);
	64	tm->tm_mday = readb(&priv->reg->date);
65	tm->tm_mon = readb(&priv->reg->month);
66	tm->tm_year = readb(&priv->reg->year);
67	writeb(control, &priv->reg->control);
68	spin_unlock_irq(&priv->lock);
69
70	tm->tm_sec = bcd2bin(tm->tm_sec);
71	tm->tm_min = bcd2bin(tm->tm_min);
72	tm->tm_hour = bcd2bin(tm->tm_hour);
73	tm->tm_mday = bcd2bin(tm->tm_mday);
74	tm->tm_mon = bcd2bin(tm->tm_mon);
75	tm->tm_year = bcd2bin(tm->tm_year);
76
77	/*
78	* Account for differences between how the RTC uses the values
79	* and how they are defined in a struct rtc_time;
80	*/
81	tm->tm_year += 70;
82	if (tm->tm_year <= 69)
83	tm->tm_year += 100;
84
85	tm->tm_mon--;
86	return rtc_valid_tm(tm);
87	}
88
89	static int m48t35_set_time(struct device dev, struct rtc_time tm)
90	{
91	struct m48t35_priv *priv = dev_get_drvdata(dev);
92	unsigned char mon, day, hrs, min, sec;
93	unsigned int yrs;
94	u8 control;
95
96	yrs = tm->tm_year + 1900;
97	mon = tm->tm_mon + 1; /* tm_mon starts at zero */
98	day = tm->tm_mday;
99	hrs = tm->tm_hour;
100	min = tm->tm_min;
101	sec = tm->tm_sec;
102
103	if (yrs < 1970)
104	return -EINVAL;
105
106	yrs -= 1970;
107	if (yrs > 255) /* They are unsigned */
108	return -EINVAL;
109
110	if (yrs > 169)
111	return -EINVAL;
112
113	if (yrs >= 100)
114	yrs -= 100;
115
116	sec = bin2bcd(sec);
117	min = bin2bcd(min);
118	hrs = bin2bcd(hrs);
119	day = bin2bcd(day);
120	mon = bin2bcd(mon);
121	yrs = bin2bcd(yrs);
122
123	spin_lock_irq(&priv->lock);
124	control = readb(&priv->reg->control);
125	writeb(control \| M48T35_RTC_SET, &priv->reg->control);
126	writeb(yrs, &priv->reg->year);
127	writeb(mon, &priv->reg->month);
128	writeb(day, &priv->reg->date);
129	writeb(hrs, &priv->reg->hour);
130	writeb(min, &priv->reg->min);
131	writeb(sec, &priv->reg->sec);
132	writeb(control, &priv->reg->control);
133	spin_unlock_irq(&priv->lock);
134	return 0;
135	}
136
137	static const struct rtc_class_ops m48t35_ops = {
138	.read_time = m48t35_read_time,
139	.set_time = m48t35_set_time,
140	};
141
142	static int __devinit m48t35_probe(struct platform_device *pdev)
143	{
144	struct rtc_device *rtc;
145	struct resource *res;
146	struct m48t35_priv *priv;
147	int ret = 0;
148
149	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
150	if (!res)
151	return -ENODEV;
152	priv = kzalloc(sizeof(struct m48t35_priv), GFP_KERNEL);
153	if (!priv)
154	return -ENOMEM;
155
156	priv->size = res->end - res->start + 1;
157	/*
158	* kludge: remove the #ifndef after ioc3 resource
159	* conflicts are resolved
160	*/
161	#ifndef CONFIG_SGI_IP27
162	if (!request_mem_region(res->start, priv->size, pdev->name)) {
163	ret = -EBUSY;
164	goto out;
165	}
166	#endif
167	priv->baseaddr = res->start;
168	priv->reg = ioremap(priv->baseaddr, priv->size);
169	if (!priv->reg) {
170	ret = -ENOMEM;
171	goto out;
172	}
173	spin_lock_init(&priv->lock);
174	rtc = rtc_device_register("m48t35", &pdev->dev,
175	&m48t35_ops, THIS_MODULE);
176	if (IS_ERR(rtc)) {
177	ret = PTR_ERR(rtc);
178	goto out;
179	}
180	priv->rtc = rtc;
181	platform_set_drvdata(pdev, priv);
182	return 0;
183
184	out:
185	if (priv->rtc)
186	rtc_device_unregister(priv->rtc);
187	if (priv->reg)
188	iounmap(priv->reg);
189	if (priv->baseaddr)
190	release_mem_region(priv->baseaddr, priv->size);
191	kfree(priv);
192	return ret;
193	}
194
195	static int __devexit m48t35_remove(struct platform_device *pdev)
196	{
197	struct m48t35_priv *priv = platform_get_drvdata(pdev);
198
199	rtc_device_unregister(priv->rtc);
200	iounmap(priv->reg);
201	#ifndef CONFIG_SGI_IP27
202	release_mem_region(priv->baseaddr, priv->size);
203	#endif
204	kfree(priv);
205	return 0;
206	}
207
208	static struct platform_driver m48t35_platform_driver = {
209	.driver = {
210	.name = "rtc-m48t35",
211	.owner = THIS_MODULE,
212	},
213	.probe = m48t35_probe,
214	.remove = __devexit_p(m48t35_remove),
215	};
216
217	static int __init m48t35_init(void)
218	{
219	return platform_driver_register(&m48t35_platform_driver);
220	}
221
222	static void __exit m48t35_exit(void)
223	{
224	platform_driver_unregister(&m48t35_platform_driver);
225	}
226
227	MODULE_AUTHOR("Thomas Bogendoerfer <tsbogend@alpha.franken.de>");
228	MODULE_DESCRIPTION("M48T35 RTC driver");
229	MODULE_LICENSE("GPL");
230	MODULE_VERSION(DRV_VERSION);
231	MODULE_ALIAS("platform:rtc-m48t35");
232
233	module_init(m48t35_init);
234	module_exit(m48t35_exit);