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v4.6
  1/*
  2 * A RTC driver for the Simtek STK17TA8
  3 *
  4 * By Thomas Hommel <thomas.hommel@ge.com>
  5 *
  6 * Based on the DS1553 driver from
  7 * Atsushi Nemoto <anemo@mba.ocn.ne.jp>
  8 *
  9 * This program is free software; you can redistribute it and/or modify
 10 * it under the terms of the GNU General Public License version 2 as
 11 * published by the Free Software Foundation.
 12 */
 13
 14#include <linux/bcd.h>
 15#include <linux/init.h>
 16#include <linux/kernel.h>
 17#include <linux/gfp.h>
 18#include <linux/delay.h>
 19#include <linux/jiffies.h>
 20#include <linux/interrupt.h>
 21#include <linux/rtc.h>
 22#include <linux/platform_device.h>
 23#include <linux/io.h>
 24#include <linux/module.h>
 25
 26#define DRV_VERSION "0.1"
 27
 28#define RTC_REG_SIZE		0x20000
 29#define RTC_OFFSET		0x1fff0
 30
 31#define RTC_FLAGS		(RTC_OFFSET + 0)
 32#define RTC_CENTURY		(RTC_OFFSET + 1)
 33#define RTC_SECONDS_ALARM	(RTC_OFFSET + 2)
 34#define RTC_MINUTES_ALARM	(RTC_OFFSET + 3)
 35#define RTC_HOURS_ALARM		(RTC_OFFSET + 4)
 36#define RTC_DATE_ALARM		(RTC_OFFSET + 5)
 37#define RTC_INTERRUPTS		(RTC_OFFSET + 6)
 38#define RTC_WATCHDOG		(RTC_OFFSET + 7)
 39#define RTC_CALIBRATION		(RTC_OFFSET + 8)
 40#define RTC_SECONDS		(RTC_OFFSET + 9)
 41#define RTC_MINUTES		(RTC_OFFSET + 10)
 42#define RTC_HOURS		(RTC_OFFSET + 11)
 43#define RTC_DAY			(RTC_OFFSET + 12)
 44#define RTC_DATE		(RTC_OFFSET + 13)
 45#define RTC_MONTH		(RTC_OFFSET + 14)
 46#define RTC_YEAR		(RTC_OFFSET + 15)
 47
 48#define RTC_SECONDS_MASK	0x7f
 49#define RTC_DAY_MASK		0x07
 50#define RTC_CAL_MASK		0x3f
 51
 52/* Bits in the Calibration register */
 53#define RTC_STOP		0x80
 54
 55/* Bits in the Flags register */
 56#define RTC_FLAGS_AF		0x40
 57#define RTC_FLAGS_PF		0x20
 58#define RTC_WRITE		0x02
 59#define RTC_READ		0x01
 60
 61/* Bits in the Interrupts register */
 62#define RTC_INTS_AIE		0x40
 63
 64struct rtc_plat_data {
 65	struct rtc_device *rtc;
 66	void __iomem *ioaddr;
 67	unsigned long last_jiffies;
 68	int irq;
 69	unsigned int irqen;
 70	int alrm_sec;
 71	int alrm_min;
 72	int alrm_hour;
 73	int alrm_mday;
 74	spinlock_t lock;
 75};
 76
 77static int stk17ta8_rtc_set_time(struct device *dev, struct rtc_time *tm)
 78{
 79	struct platform_device *pdev = to_platform_device(dev);
 80	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 81	void __iomem *ioaddr = pdata->ioaddr;
 82	u8 flags;
 83
 84	flags = readb(pdata->ioaddr + RTC_FLAGS);
 85	writeb(flags | RTC_WRITE, pdata->ioaddr + RTC_FLAGS);
 86
 87	writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR);
 88	writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH);
 89	writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
 90	writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE);
 91	writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS);
 92	writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES);
 93	writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);
 94	writeb(bin2bcd((tm->tm_year + 1900) / 100), ioaddr + RTC_CENTURY);
 95
 96	writeb(flags & ~RTC_WRITE, pdata->ioaddr + RTC_FLAGS);
 97	return 0;
 98}
 99
100static int stk17ta8_rtc_read_time(struct device *dev, struct rtc_time *tm)
101{
102	struct platform_device *pdev = to_platform_device(dev);
103	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
104	void __iomem *ioaddr = pdata->ioaddr;
105	unsigned int year, month, day, hour, minute, second, week;
106	unsigned int century;
107	u8 flags;
108
109	/* give enough time to update RTC in case of continuous read */
110	if (pdata->last_jiffies == jiffies)
111		msleep(1);
112	pdata->last_jiffies = jiffies;
113
114	flags = readb(pdata->ioaddr + RTC_FLAGS);
115	writeb(flags | RTC_READ, ioaddr + RTC_FLAGS);
116	second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
117	minute = readb(ioaddr + RTC_MINUTES);
118	hour = readb(ioaddr + RTC_HOURS);
119	day = readb(ioaddr + RTC_DATE);
120	week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
121	month = readb(ioaddr + RTC_MONTH);
122	year = readb(ioaddr + RTC_YEAR);
123	century = readb(ioaddr + RTC_CENTURY);
124	writeb(flags & ~RTC_READ, ioaddr + RTC_FLAGS);
125	tm->tm_sec = bcd2bin(second);
126	tm->tm_min = bcd2bin(minute);
127	tm->tm_hour = bcd2bin(hour);
128	tm->tm_mday = bcd2bin(day);
129	tm->tm_wday = bcd2bin(week);
130	tm->tm_mon = bcd2bin(month) - 1;
131	/* year is 1900 + tm->tm_year */
132	tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900;
133
134	if (rtc_valid_tm(tm) < 0) {
135		dev_err(dev, "retrieved date/time is not valid.\n");
136		rtc_time_to_tm(0, tm);
137	}
138	return 0;
139}
140
141static void stk17ta8_rtc_update_alarm(struct rtc_plat_data *pdata)
142{
143	void __iomem *ioaddr = pdata->ioaddr;
144	unsigned long irqflags;
145	u8 flags;
146
147	spin_lock_irqsave(&pdata->lock, irqflags);
148
149	flags = readb(ioaddr + RTC_FLAGS);
150	writeb(flags | RTC_WRITE, ioaddr + RTC_FLAGS);
151
152	writeb(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ?
153	       0x80 : bin2bcd(pdata->alrm_mday),
154	       ioaddr + RTC_DATE_ALARM);
155	writeb(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ?
156	       0x80 : bin2bcd(pdata->alrm_hour),
157	       ioaddr + RTC_HOURS_ALARM);
158	writeb(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ?
159	       0x80 : bin2bcd(pdata->alrm_min),
160	       ioaddr + RTC_MINUTES_ALARM);
161	writeb(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ?
162	       0x80 : bin2bcd(pdata->alrm_sec),
163	       ioaddr + RTC_SECONDS_ALARM);
164	writeb(pdata->irqen ? RTC_INTS_AIE : 0, ioaddr + RTC_INTERRUPTS);
165	readb(ioaddr + RTC_FLAGS);	/* clear interrupts */
166	writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS);
167	spin_unlock_irqrestore(&pdata->lock, irqflags);
168}
169
170static int stk17ta8_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
171{
172	struct platform_device *pdev = to_platform_device(dev);
173	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
174
175	if (pdata->irq <= 0)
176		return -EINVAL;
177	pdata->alrm_mday = alrm->time.tm_mday;
178	pdata->alrm_hour = alrm->time.tm_hour;
179	pdata->alrm_min = alrm->time.tm_min;
180	pdata->alrm_sec = alrm->time.tm_sec;
181	if (alrm->enabled)
182		pdata->irqen |= RTC_AF;
183	stk17ta8_rtc_update_alarm(pdata);
184	return 0;
185}
186
187static int stk17ta8_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
188{
189	struct platform_device *pdev = to_platform_device(dev);
190	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
191
192	if (pdata->irq <= 0)
193		return -EINVAL;
194	alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
195	alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
196	alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
197	alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
198	alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
199	return 0;
200}
201
202static irqreturn_t stk17ta8_rtc_interrupt(int irq, void *dev_id)
203{
204	struct platform_device *pdev = dev_id;
205	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
206	void __iomem *ioaddr = pdata->ioaddr;
207	unsigned long events = 0;
208
209	spin_lock(&pdata->lock);
210	/* read and clear interrupt */
211	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF) {
212		events = RTC_IRQF;
213		if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80)
214			events |= RTC_UF;
215		else
216			events |= RTC_AF;
217		rtc_update_irq(pdata->rtc, 1, events);
 
218	}
219	spin_unlock(&pdata->lock);
220	return events ? IRQ_HANDLED : IRQ_NONE;
221}
222
223static int stk17ta8_rtc_alarm_irq_enable(struct device *dev,
224	unsigned int enabled)
225{
226	struct platform_device *pdev = to_platform_device(dev);
227	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
228
229	if (pdata->irq <= 0)
230		return -EINVAL;
231	if (enabled)
232		pdata->irqen |= RTC_AF;
233	else
234		pdata->irqen &= ~RTC_AF;
235	stk17ta8_rtc_update_alarm(pdata);
236	return 0;
237}
238
239static const struct rtc_class_ops stk17ta8_rtc_ops = {
240	.read_time		= stk17ta8_rtc_read_time,
241	.set_time		= stk17ta8_rtc_set_time,
242	.read_alarm		= stk17ta8_rtc_read_alarm,
243	.set_alarm		= stk17ta8_rtc_set_alarm,
244	.alarm_irq_enable	= stk17ta8_rtc_alarm_irq_enable,
245};
246
247static ssize_t stk17ta8_nvram_read(struct file *filp, struct kobject *kobj,
248				 struct bin_attribute *attr, char *buf,
249				 loff_t pos, size_t size)
250{
251	struct device *dev = container_of(kobj, struct device, kobj);
252	struct platform_device *pdev = to_platform_device(dev);
253	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
254	void __iomem *ioaddr = pdata->ioaddr;
255	ssize_t count;
256
257	for (count = 0; count < size; count++)
258		*buf++ = readb(ioaddr + pos++);
259	return count;
260}
261
262static ssize_t stk17ta8_nvram_write(struct file *filp, struct kobject *kobj,
263				  struct bin_attribute *attr, char *buf,
264				  loff_t pos, size_t size)
265{
266	struct device *dev = container_of(kobj, struct device, kobj);
267	struct platform_device *pdev = to_platform_device(dev);
268	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
269	void __iomem *ioaddr = pdata->ioaddr;
270	ssize_t count;
271
272	for (count = 0; count < size; count++)
273		writeb(*buf++, ioaddr + pos++);
274	return count;
275}
276
277static struct bin_attribute stk17ta8_nvram_attr = {
278	.attr = {
279		.name = "nvram",
280		.mode = S_IRUGO | S_IWUSR,
281	},
282	.size = RTC_OFFSET,
283	.read = stk17ta8_nvram_read,
284	.write = stk17ta8_nvram_write,
285};
286
287static int stk17ta8_rtc_probe(struct platform_device *pdev)
288{
289	struct resource *res;
290	unsigned int cal;
291	unsigned int flags;
292	struct rtc_plat_data *pdata;
293	void __iomem *ioaddr;
294	int ret = 0;
295
 
 
 
 
296	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
297	if (!pdata)
298		return -ENOMEM;
299
300	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
301	ioaddr = devm_ioremap_resource(&pdev->dev, res);
302	if (IS_ERR(ioaddr))
303		return PTR_ERR(ioaddr);
 
304	pdata->ioaddr = ioaddr;
305	pdata->irq = platform_get_irq(pdev, 0);
306
307	/* turn RTC on if it was not on */
308	cal = readb(ioaddr + RTC_CALIBRATION);
309	if (cal & RTC_STOP) {
310		cal &= RTC_CAL_MASK;
311		flags = readb(ioaddr + RTC_FLAGS);
312		writeb(flags | RTC_WRITE, ioaddr + RTC_FLAGS);
313		writeb(cal, ioaddr + RTC_CALIBRATION);
314		writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS);
315	}
316	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_PF)
317		dev_warn(&pdev->dev, "voltage-low detected.\n");
318
319	spin_lock_init(&pdata->lock);
320	pdata->last_jiffies = jiffies;
321	platform_set_drvdata(pdev, pdata);
322	if (pdata->irq > 0) {
323		writeb(0, ioaddr + RTC_INTERRUPTS);
324		if (devm_request_irq(&pdev->dev, pdata->irq,
325				stk17ta8_rtc_interrupt,
326				IRQF_SHARED,
327				pdev->name, pdev) < 0) {
328			dev_warn(&pdev->dev, "interrupt not available.\n");
329			pdata->irq = 0;
330		}
331	}
332
333	pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
334				  &stk17ta8_rtc_ops, THIS_MODULE);
335	if (IS_ERR(pdata->rtc))
336		return PTR_ERR(pdata->rtc);
337
338	ret = sysfs_create_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr);
339
 
340	return ret;
341}
342
343static int stk17ta8_rtc_remove(struct platform_device *pdev)
344{
345	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
346
347	sysfs_remove_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr);
 
348	if (pdata->irq > 0)
349		writeb(0, pdata->ioaddr + RTC_INTERRUPTS);
350	return 0;
351}
352
353/* work with hotplug and coldplug */
354MODULE_ALIAS("platform:stk17ta8");
355
356static struct platform_driver stk17ta8_rtc_driver = {
357	.probe		= stk17ta8_rtc_probe,
358	.remove		= stk17ta8_rtc_remove,
359	.driver		= {
360		.name	= "stk17ta8",
 
361	},
362};
363
364module_platform_driver(stk17ta8_rtc_driver);
 
 
 
 
 
 
 
 
 
 
 
365
366MODULE_AUTHOR("Thomas Hommel <thomas.hommel@ge.com>");
367MODULE_DESCRIPTION("Simtek STK17TA8 RTC driver");
368MODULE_LICENSE("GPL");
369MODULE_VERSION(DRV_VERSION);
v3.1
  1/*
  2 * A RTC driver for the Simtek STK17TA8
  3 *
  4 * By Thomas Hommel <thomas.hommel@ge.com>
  5 *
  6 * Based on the DS1553 driver from
  7 * Atsushi Nemoto <anemo@mba.ocn.ne.jp>
  8 *
  9 * This program is free software; you can redistribute it and/or modify
 10 * it under the terms of the GNU General Public License version 2 as
 11 * published by the Free Software Foundation.
 12 */
 13
 14#include <linux/bcd.h>
 15#include <linux/init.h>
 16#include <linux/kernel.h>
 17#include <linux/gfp.h>
 18#include <linux/delay.h>
 19#include <linux/jiffies.h>
 20#include <linux/interrupt.h>
 21#include <linux/rtc.h>
 22#include <linux/platform_device.h>
 23#include <linux/io.h>
 
 24
 25#define DRV_VERSION "0.1"
 26
 27#define RTC_REG_SIZE		0x20000
 28#define RTC_OFFSET		0x1fff0
 29
 30#define RTC_FLAGS		(RTC_OFFSET + 0)
 31#define RTC_CENTURY		(RTC_OFFSET + 1)
 32#define RTC_SECONDS_ALARM	(RTC_OFFSET + 2)
 33#define RTC_MINUTES_ALARM	(RTC_OFFSET + 3)
 34#define RTC_HOURS_ALARM		(RTC_OFFSET + 4)
 35#define RTC_DATE_ALARM		(RTC_OFFSET + 5)
 36#define RTC_INTERRUPTS		(RTC_OFFSET + 6)
 37#define RTC_WATCHDOG		(RTC_OFFSET + 7)
 38#define RTC_CALIBRATION		(RTC_OFFSET + 8)
 39#define RTC_SECONDS		(RTC_OFFSET + 9)
 40#define RTC_MINUTES		(RTC_OFFSET + 10)
 41#define RTC_HOURS		(RTC_OFFSET + 11)
 42#define RTC_DAY			(RTC_OFFSET + 12)
 43#define RTC_DATE		(RTC_OFFSET + 13)
 44#define RTC_MONTH		(RTC_OFFSET + 14)
 45#define RTC_YEAR		(RTC_OFFSET + 15)
 46
 47#define RTC_SECONDS_MASK	0x7f
 48#define RTC_DAY_MASK		0x07
 49#define RTC_CAL_MASK		0x3f
 50
 51/* Bits in the Calibration register */
 52#define RTC_STOP		0x80
 53
 54/* Bits in the Flags register */
 55#define RTC_FLAGS_AF		0x40
 56#define RTC_FLAGS_PF		0x20
 57#define RTC_WRITE		0x02
 58#define RTC_READ		0x01
 59
 60/* Bits in the Interrupts register */
 61#define RTC_INTS_AIE		0x40
 62
 63struct rtc_plat_data {
 64	struct rtc_device *rtc;
 65	void __iomem *ioaddr;
 66	unsigned long last_jiffies;
 67	int irq;
 68	unsigned int irqen;
 69	int alrm_sec;
 70	int alrm_min;
 71	int alrm_hour;
 72	int alrm_mday;
 73	spinlock_t lock;
 74};
 75
 76static int stk17ta8_rtc_set_time(struct device *dev, struct rtc_time *tm)
 77{
 78	struct platform_device *pdev = to_platform_device(dev);
 79	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 80	void __iomem *ioaddr = pdata->ioaddr;
 81	u8 flags;
 82
 83	flags = readb(pdata->ioaddr + RTC_FLAGS);
 84	writeb(flags | RTC_WRITE, pdata->ioaddr + RTC_FLAGS);
 85
 86	writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR);
 87	writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH);
 88	writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
 89	writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE);
 90	writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS);
 91	writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES);
 92	writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);
 93	writeb(bin2bcd((tm->tm_year + 1900) / 100), ioaddr + RTC_CENTURY);
 94
 95	writeb(flags & ~RTC_WRITE, pdata->ioaddr + RTC_FLAGS);
 96	return 0;
 97}
 98
 99static int stk17ta8_rtc_read_time(struct device *dev, struct rtc_time *tm)
100{
101	struct platform_device *pdev = to_platform_device(dev);
102	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
103	void __iomem *ioaddr = pdata->ioaddr;
104	unsigned int year, month, day, hour, minute, second, week;
105	unsigned int century;
106	u8 flags;
107
108	/* give enough time to update RTC in case of continuous read */
109	if (pdata->last_jiffies == jiffies)
110		msleep(1);
111	pdata->last_jiffies = jiffies;
112
113	flags = readb(pdata->ioaddr + RTC_FLAGS);
114	writeb(flags | RTC_READ, ioaddr + RTC_FLAGS);
115	second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
116	minute = readb(ioaddr + RTC_MINUTES);
117	hour = readb(ioaddr + RTC_HOURS);
118	day = readb(ioaddr + RTC_DATE);
119	week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
120	month = readb(ioaddr + RTC_MONTH);
121	year = readb(ioaddr + RTC_YEAR);
122	century = readb(ioaddr + RTC_CENTURY);
123	writeb(flags & ~RTC_READ, ioaddr + RTC_FLAGS);
124	tm->tm_sec = bcd2bin(second);
125	tm->tm_min = bcd2bin(minute);
126	tm->tm_hour = bcd2bin(hour);
127	tm->tm_mday = bcd2bin(day);
128	tm->tm_wday = bcd2bin(week);
129	tm->tm_mon = bcd2bin(month) - 1;
130	/* year is 1900 + tm->tm_year */
131	tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900;
132
133	if (rtc_valid_tm(tm) < 0) {
134		dev_err(dev, "retrieved date/time is not valid.\n");
135		rtc_time_to_tm(0, tm);
136	}
137	return 0;
138}
139
140static void stk17ta8_rtc_update_alarm(struct rtc_plat_data *pdata)
141{
142	void __iomem *ioaddr = pdata->ioaddr;
143	unsigned long irqflags;
144	u8 flags;
145
146	spin_lock_irqsave(&pdata->lock, irqflags);
147
148	flags = readb(ioaddr + RTC_FLAGS);
149	writeb(flags | RTC_WRITE, ioaddr + RTC_FLAGS);
150
151	writeb(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ?
152	       0x80 : bin2bcd(pdata->alrm_mday),
153	       ioaddr + RTC_DATE_ALARM);
154	writeb(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ?
155	       0x80 : bin2bcd(pdata->alrm_hour),
156	       ioaddr + RTC_HOURS_ALARM);
157	writeb(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ?
158	       0x80 : bin2bcd(pdata->alrm_min),
159	       ioaddr + RTC_MINUTES_ALARM);
160	writeb(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ?
161	       0x80 : bin2bcd(pdata->alrm_sec),
162	       ioaddr + RTC_SECONDS_ALARM);
163	writeb(pdata->irqen ? RTC_INTS_AIE : 0, ioaddr + RTC_INTERRUPTS);
164	readb(ioaddr + RTC_FLAGS);	/* clear interrupts */
165	writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS);
166	spin_unlock_irqrestore(&pdata->lock, irqflags);
167}
168
169static int stk17ta8_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
170{
171	struct platform_device *pdev = to_platform_device(dev);
172	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
173
174	if (pdata->irq <= 0)
175		return -EINVAL;
176	pdata->alrm_mday = alrm->time.tm_mday;
177	pdata->alrm_hour = alrm->time.tm_hour;
178	pdata->alrm_min = alrm->time.tm_min;
179	pdata->alrm_sec = alrm->time.tm_sec;
180	if (alrm->enabled)
181		pdata->irqen |= RTC_AF;
182	stk17ta8_rtc_update_alarm(pdata);
183	return 0;
184}
185
186static int stk17ta8_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
187{
188	struct platform_device *pdev = to_platform_device(dev);
189	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
190
191	if (pdata->irq <= 0)
192		return -EINVAL;
193	alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
194	alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
195	alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
196	alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
197	alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
198	return 0;
199}
200
201static irqreturn_t stk17ta8_rtc_interrupt(int irq, void *dev_id)
202{
203	struct platform_device *pdev = dev_id;
204	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
205	void __iomem *ioaddr = pdata->ioaddr;
206	unsigned long events = 0;
207
208	spin_lock(&pdata->lock);
209	/* read and clear interrupt */
210	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF) {
211		events = RTC_IRQF;
212		if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80)
213			events |= RTC_UF;
214		else
215			events |= RTC_AF;
216		if (likely(pdata->rtc))
217			rtc_update_irq(pdata->rtc, 1, events);
218	}
219	spin_unlock(&pdata->lock);
220	return events ? IRQ_HANDLED : IRQ_NONE;
221}
222
223static int stk17ta8_rtc_alarm_irq_enable(struct device *dev,
224	unsigned int enabled)
225{
226	struct platform_device *pdev = to_platform_device(dev);
227	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
228
229	if (pdata->irq <= 0)
230		return -EINVAL;
231	if (enabled)
232		pdata->irqen |= RTC_AF;
233	else
234		pdata->irqen &= ~RTC_AF;
235	stk17ta8_rtc_update_alarm(pdata);
236	return 0;
237}
238
239static const struct rtc_class_ops stk17ta8_rtc_ops = {
240	.read_time		= stk17ta8_rtc_read_time,
241	.set_time		= stk17ta8_rtc_set_time,
242	.read_alarm		= stk17ta8_rtc_read_alarm,
243	.set_alarm		= stk17ta8_rtc_set_alarm,
244	.alarm_irq_enable	= stk17ta8_rtc_alarm_irq_enable,
245};
246
247static ssize_t stk17ta8_nvram_read(struct file *filp, struct kobject *kobj,
248				 struct bin_attribute *attr, char *buf,
249				 loff_t pos, size_t size)
250{
251	struct device *dev = container_of(kobj, struct device, kobj);
252	struct platform_device *pdev = to_platform_device(dev);
253	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
254	void __iomem *ioaddr = pdata->ioaddr;
255	ssize_t count;
256
257	for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
258		*buf++ = readb(ioaddr + pos++);
259	return count;
260}
261
262static ssize_t stk17ta8_nvram_write(struct file *filp, struct kobject *kobj,
263				  struct bin_attribute *attr, char *buf,
264				  loff_t pos, size_t size)
265{
266	struct device *dev = container_of(kobj, struct device, kobj);
267	struct platform_device *pdev = to_platform_device(dev);
268	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
269	void __iomem *ioaddr = pdata->ioaddr;
270	ssize_t count;
271
272	for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
273		writeb(*buf++, ioaddr + pos++);
274	return count;
275}
276
277static struct bin_attribute stk17ta8_nvram_attr = {
278	.attr = {
279		.name = "nvram",
280		.mode = S_IRUGO | S_IWUSR,
281	},
282	.size = RTC_OFFSET,
283	.read = stk17ta8_nvram_read,
284	.write = stk17ta8_nvram_write,
285};
286
287static int __devinit stk17ta8_rtc_probe(struct platform_device *pdev)
288{
289	struct resource *res;
290	unsigned int cal;
291	unsigned int flags;
292	struct rtc_plat_data *pdata;
293	void __iomem *ioaddr;
294	int ret = 0;
295
296	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
297	if (!res)
298		return -ENODEV;
299
300	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
301	if (!pdata)
302		return -ENOMEM;
303	if (!devm_request_mem_region(&pdev->dev, res->start, RTC_REG_SIZE,
304			pdev->name))
305		return -EBUSY;
306	ioaddr = devm_ioremap(&pdev->dev, res->start, RTC_REG_SIZE);
307	if (!ioaddr)
308		return -ENOMEM;
309	pdata->ioaddr = ioaddr;
310	pdata->irq = platform_get_irq(pdev, 0);
311
312	/* turn RTC on if it was not on */
313	cal = readb(ioaddr + RTC_CALIBRATION);
314	if (cal & RTC_STOP) {
315		cal &= RTC_CAL_MASK;
316		flags = readb(ioaddr + RTC_FLAGS);
317		writeb(flags | RTC_WRITE, ioaddr + RTC_FLAGS);
318		writeb(cal, ioaddr + RTC_CALIBRATION);
319		writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS);
320	}
321	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_PF)
322		dev_warn(&pdev->dev, "voltage-low detected.\n");
323
324	spin_lock_init(&pdata->lock);
325	pdata->last_jiffies = jiffies;
326	platform_set_drvdata(pdev, pdata);
327	if (pdata->irq > 0) {
328		writeb(0, ioaddr + RTC_INTERRUPTS);
329		if (devm_request_irq(&pdev->dev, pdata->irq,
330				stk17ta8_rtc_interrupt,
331				IRQF_DISABLED | IRQF_SHARED,
332				pdev->name, pdev) < 0) {
333			dev_warn(&pdev->dev, "interrupt not available.\n");
334			pdata->irq = 0;
335		}
336	}
337
338	pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
339				  &stk17ta8_rtc_ops, THIS_MODULE);
340	if (IS_ERR(pdata->rtc))
341		return PTR_ERR(pdata->rtc);
342
343	ret = sysfs_create_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr);
344	if (ret)
345		rtc_device_unregister(pdata->rtc);
346	return ret;
347}
348
349static int __devexit stk17ta8_rtc_remove(struct platform_device *pdev)
350{
351	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
352
353	sysfs_remove_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr);
354	rtc_device_unregister(pdata->rtc);
355	if (pdata->irq > 0)
356		writeb(0, pdata->ioaddr + RTC_INTERRUPTS);
357	return 0;
358}
359
360/* work with hotplug and coldplug */
361MODULE_ALIAS("platform:stk17ta8");
362
363static struct platform_driver stk17ta8_rtc_driver = {
364	.probe		= stk17ta8_rtc_probe,
365	.remove		= __devexit_p(stk17ta8_rtc_remove),
366	.driver		= {
367		.name	= "stk17ta8",
368		.owner	= THIS_MODULE,
369	},
370};
371
372static __init int stk17ta8_init(void)
373{
374	return platform_driver_register(&stk17ta8_rtc_driver);
375}
376
377static __exit void stk17ta8_exit(void)
378{
379	platform_driver_unregister(&stk17ta8_rtc_driver);
380}
381
382module_init(stk17ta8_init);
383module_exit(stk17ta8_exit);
384
385MODULE_AUTHOR("Thomas Hommel <thomas.hommel@ge.com>");
386MODULE_DESCRIPTION("Simtek STK17TA8 RTC driver");
387MODULE_LICENSE("GPL");
388MODULE_VERSION(DRV_VERSION);