[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 ([email protected])
 *
 * 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/slab.h>
#include <linux/platform_device.h>
#include <linux/bcd.h>
#include <linux/io.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 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 = resource_size(res);
	/*
	 * 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);

	platform_set_drvdata(pdev, priv);

	priv->rtc = rtc_device_register("m48t35", &pdev->dev,
				  &m48t35_ops, THIS_MODULE);
	if (IS_ERR(priv->rtc)) {
		ret = PTR_ERR(priv->rtc);
		goto out;
	}

	return 0;

out:
	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),
};

module_platform_driver(m48t35_platform_driver);

MODULE_AUTHOR("Thomas Bogendoerfer <[email protected]>");
MODULE_DESCRIPTION("M48T35 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
MODULE_ALIAS("platform:rtc-m48t35");
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 ([email protected])
	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>
5a0e3ad6	19	#include <linux/slab.h>
d1dbd82e TB	20	#include <linux/platform_device.h>
d1dbd82e TB	21	#include <linux/bcd.h>
d7a6119f	22	#include <linux/io.h>
d1dbd82e TB	23
	24	#define DRV_VERSION "1.0"
	25
	26	struct m48t35_rtc {
	27	u8 pad[0x7ff8]; /* starts at 0x7ff8 */
	28	u8 control;
	29	u8 sec;
	30	u8 min;
	31	u8 hour;
	32	u8 day;
	33	u8 date;
	34	u8 month;
	35	u8 year;
	36	};
	37
	38	#define M48T35_RTC_SET 0x80
	39	#define M48T35_RTC_READ 0x40
	40
	41	struct m48t35_priv {
	42	struct rtc_device *rtc;
	43	struct m48t35_rtc __iomem *reg;
	44	size_t size;
	45	unsigned long baseaddr;
	46	spinlock_t lock;
	47	};
	48
	49	static int m48t35_read_time(struct device dev, struct rtc_time tm)
	50	{
	51	struct m48t35_priv *priv = dev_get_drvdata(dev);
	52	u8 control;
	53
	54	/*
	55	* Only the values that we read from the RTC are set. We leave
	56	* tm_wday, tm_yday and tm_isdst untouched. Even though the
	57	* RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
	58	* by the RTC when initially set to a non-zero value.
	59	*/
	60	spin_lock_irq(&priv->lock);
	61	control = readb(&priv->reg->control);
	62	writeb(control \| M48T35_RTC_READ, &priv->reg->control);
	63	tm->tm_sec = readb(&priv->reg->sec);
	64	tm->tm_min = readb(&priv->reg->min);
	65	tm->tm_hour = readb(&priv->reg->hour);
	66	tm->tm_mday = readb(&priv->reg->date);
	67	tm->tm_mon = readb(&priv->reg->month);
	68	tm->tm_year = readb(&priv->reg->year);
	69	writeb(control, &priv->reg->control);
	70	spin_unlock_irq(&priv->lock);
	71
	72	tm->tm_sec = bcd2bin(tm->tm_sec);
	73	tm->tm_min = bcd2bin(tm->tm_min);
	74	tm->tm_hour = bcd2bin(tm->tm_hour);
	75	tm->tm_mday = bcd2bin(tm->tm_mday);
	76	tm->tm_mon = bcd2bin(tm->tm_mon);
	77	tm->tm_year = bcd2bin(tm->tm_year);
	78
	79	/*
	80	* Account for differences between how the RTC uses the values
	81	* and how they are defined in a struct rtc_time;
	82	*/
	83	tm->tm_year += 70;
	84	if (tm->tm_year <= 69)
	85	tm->tm_year += 100;
	86
87	tm->tm_mon--;
88	return rtc_valid_tm(tm);
89	}
90
91	static int m48t35_set_time(struct device dev, struct rtc_time tm)
92	{
93	struct m48t35_priv *priv = dev_get_drvdata(dev);
94	unsigned char mon, day, hrs, min, sec;
95	unsigned int yrs;
96	u8 control;
97
98	yrs = tm->tm_year + 1900;
99	mon = tm->tm_mon + 1; /* tm_mon starts at zero */
100	day = tm->tm_mday;
101	hrs = tm->tm_hour;
102	min = tm->tm_min;
103	sec = tm->tm_sec;
104
105	if (yrs < 1970)
106	return -EINVAL;
107
108	yrs -= 1970;
109	if (yrs > 255) /* They are unsigned */
110	return -EINVAL;
111
112	if (yrs > 169)
113	return -EINVAL;
114
115	if (yrs >= 100)
116	yrs -= 100;
117
118	sec = bin2bcd(sec);
119	min = bin2bcd(min);
120	hrs = bin2bcd(hrs);
121	day = bin2bcd(day);
122	mon = bin2bcd(mon);
123	yrs = bin2bcd(yrs);
124
125	spin_lock_irq(&priv->lock);
126	control = readb(&priv->reg->control);
127	writeb(control \| M48T35_RTC_SET, &priv->reg->control);
128	writeb(yrs, &priv->reg->year);
129	writeb(mon, &priv->reg->month);
130	writeb(day, &priv->reg->date);
131	writeb(hrs, &priv->reg->hour);
132	writeb(min, &priv->reg->min);
133	writeb(sec, &priv->reg->sec);
134	writeb(control, &priv->reg->control);
135	spin_unlock_irq(&priv->lock);
136	return 0;
137	}
138
139	static const struct rtc_class_ops m48t35_ops = {
140	.read_time = m48t35_read_time,
141	.set_time = m48t35_set_time,
142	};
143
144	static int __devinit m48t35_probe(struct platform_device *pdev)
145	{
d1dbd82e TB	146	struct resource *res;
	147	struct m48t35_priv *priv;
	148	int ret = 0;
	149
	150	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	151	if (!res)
	152	return -ENODEV;
	153	priv = kzalloc(sizeof(struct m48t35_priv), GFP_KERNEL);
	154	if (!priv)
	155	return -ENOMEM;
	156
28f65c11	157	priv->size = resource_size(res);
d1dbd82e TB	158	/*
	159	* kludge: remove the #ifndef after ioc3 resource
	160	* conflicts are resolved
	161	*/
	162	#ifndef CONFIG_SGI_IP27
	163	if (!request_mem_region(res->start, priv->size, pdev->name)) {
	164	ret = -EBUSY;
	165	goto out;
	166	}
	167	#endif
	168	priv->baseaddr = res->start;
	169	priv->reg = ioremap(priv->baseaddr, priv->size);
	170	if (!priv->reg) {
	171	ret = -ENOMEM;
	172	goto out;
	173	}
b74d2caa	174
d1dbd82e	175	spin_lock_init(&priv->lock);
b74d2caa AZ	176
	177	platform_set_drvdata(pdev, priv);
	178
	179	priv->rtc = rtc_device_register("m48t35", &pdev->dev,
d1dbd82e	180	&m48t35_ops, THIS_MODULE);
b74d2caa AZ	181	if (IS_ERR(priv->rtc)) {
b74d2caa AZ	182	ret = PTR_ERR(priv->rtc);
d1dbd82e TB	183	goto out;
d1dbd82e TB	184	}
b74d2caa	185
d1dbd82e TB	186	return 0;
	187
	188	out:
d1dbd82e TB	189	if (priv->reg)
	190	iounmap(priv->reg);
	191	if (priv->baseaddr)
	192	release_mem_region(priv->baseaddr, priv->size);
	193	kfree(priv);
	194	return ret;
	195	}
	196
	197	static int __devexit m48t35_remove(struct platform_device *pdev)
	198	{
	199	struct m48t35_priv *priv = platform_get_drvdata(pdev);
	200
	201	rtc_device_unregister(priv->rtc);
	202	iounmap(priv->reg);
	203	#ifndef CONFIG_SGI_IP27
	204	release_mem_region(priv->baseaddr, priv->size);
	205	#endif
	206	kfree(priv);
	207	return 0;
	208	}
	209
	210	static struct platform_driver m48t35_platform_driver = {
	211	.driver = {
	212	.name = "rtc-m48t35",
	213	.owner = THIS_MODULE,
	214	},
	215	.probe = m48t35_probe,
	216	.remove = __devexit_p(m48t35_remove),
	217	};
	218
0c4eae66	219	module_platform_driver(m48t35_platform_driver);
d1dbd82e TB	220
	221	MODULE_AUTHOR("Thomas Bogendoerfer <[email protected]>");
	222	MODULE_DESCRIPTION("M48T35 RTC driver");
	223	MODULE_LICENSE("GPL");
	224	MODULE_VERSION(DRV_VERSION);
	225	MODULE_ALIAS("platform:rtc-m48t35");