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v4.10.11
  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 RTC_REG_SIZE		0x20000
 27#define RTC_OFFSET		0x1fff0
 28
 29#define RTC_FLAGS		(RTC_OFFSET + 0)
 30#define RTC_CENTURY		(RTC_OFFSET + 1)
 31#define RTC_SECONDS_ALARM	(RTC_OFFSET + 2)
 32#define RTC_MINUTES_ALARM	(RTC_OFFSET + 3)
 33#define RTC_HOURS_ALARM		(RTC_OFFSET + 4)
 34#define RTC_DATE_ALARM		(RTC_OFFSET + 5)
 35#define RTC_INTERRUPTS		(RTC_OFFSET + 6)
 36#define RTC_WATCHDOG		(RTC_OFFSET + 7)
 37#define RTC_CALIBRATION		(RTC_OFFSET + 8)
 38#define RTC_SECONDS		(RTC_OFFSET + 9)
 39#define RTC_MINUTES		(RTC_OFFSET + 10)
 40#define RTC_HOURS		(RTC_OFFSET + 11)
 41#define RTC_DAY			(RTC_OFFSET + 12)
 42#define RTC_DATE		(RTC_OFFSET + 13)
 43#define RTC_MONTH		(RTC_OFFSET + 14)
 44#define RTC_YEAR		(RTC_OFFSET + 15)
 45
 46#define RTC_SECONDS_MASK	0x7f
 47#define RTC_DAY_MASK		0x07
 48#define RTC_CAL_MASK		0x3f
 49
 50/* Bits in the Calibration register */
 51#define RTC_STOP		0x80
 52
 53/* Bits in the Flags register */
 54#define RTC_FLAGS_AF		0x40
 55#define RTC_FLAGS_PF		0x20
 56#define RTC_WRITE		0x02
 57#define RTC_READ		0x01
 58
 59/* Bits in the Interrupts register */
 60#define RTC_INTS_AIE		0x40
 61
 62struct rtc_plat_data {
 63	struct rtc_device *rtc;
 64	void __iomem *ioaddr;
 65	unsigned long last_jiffies;
 66	int irq;
 67	unsigned int irqen;
 68	int alrm_sec;
 69	int alrm_min;
 70	int alrm_hour;
 71	int alrm_mday;
 72	spinlock_t lock;
 73};
 74
 75static int stk17ta8_rtc_set_time(struct device *dev, struct rtc_time *tm)
 76{
 77	struct platform_device *pdev = to_platform_device(dev);
 78	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 79	void __iomem *ioaddr = pdata->ioaddr;
 80	u8 flags;
 81
 82	flags = readb(pdata->ioaddr + RTC_FLAGS);
 83	writeb(flags | RTC_WRITE, pdata->ioaddr + RTC_FLAGS);
 84
 85	writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR);
 86	writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH);
 87	writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
 88	writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE);
 89	writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS);
 90	writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES);
 91	writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);
 92	writeb(bin2bcd((tm->tm_year + 1900) / 100), ioaddr + RTC_CENTURY);
 93
 94	writeb(flags & ~RTC_WRITE, pdata->ioaddr + RTC_FLAGS);
 95	return 0;
 96}
 97
 98static int stk17ta8_rtc_read_time(struct device *dev, struct rtc_time *tm)
 99{
100	struct platform_device *pdev = to_platform_device(dev);
101	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
102	void __iomem *ioaddr = pdata->ioaddr;
103	unsigned int year, month, day, hour, minute, second, week;
104	unsigned int century;
105	u8 flags;
106
107	/* give enough time to update RTC in case of continuous read */
108	if (pdata->last_jiffies == jiffies)
109		msleep(1);
110	pdata->last_jiffies = jiffies;
111
112	flags = readb(pdata->ioaddr + RTC_FLAGS);
113	writeb(flags | RTC_READ, ioaddr + RTC_FLAGS);
114	second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
115	minute = readb(ioaddr + RTC_MINUTES);
116	hour = readb(ioaddr + RTC_HOURS);
117	day = readb(ioaddr + RTC_DATE);
118	week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
119	month = readb(ioaddr + RTC_MONTH);
120	year = readb(ioaddr + RTC_YEAR);
121	century = readb(ioaddr + RTC_CENTURY);
122	writeb(flags & ~RTC_READ, ioaddr + RTC_FLAGS);
123	tm->tm_sec = bcd2bin(second);
124	tm->tm_min = bcd2bin(minute);
125	tm->tm_hour = bcd2bin(hour);
126	tm->tm_mday = bcd2bin(day);
127	tm->tm_wday = bcd2bin(week);
128	tm->tm_mon = bcd2bin(month) - 1;
129	/* year is 1900 + tm->tm_year */
130	tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900;
131
132	if (rtc_valid_tm(tm) < 0) {
133		dev_err(dev, "retrieved date/time is not valid.\n");
134		rtc_time_to_tm(0, tm);
135	}
136	return 0;
137}
138
139static void stk17ta8_rtc_update_alarm(struct rtc_plat_data *pdata)
140{
141	void __iomem *ioaddr = pdata->ioaddr;
142	unsigned long irqflags;
143	u8 flags;
144
145	spin_lock_irqsave(&pdata->lock, irqflags);
146
147	flags = readb(ioaddr + RTC_FLAGS);
148	writeb(flags | RTC_WRITE, ioaddr + RTC_FLAGS);
149
150	writeb(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ?
151	       0x80 : bin2bcd(pdata->alrm_mday),
152	       ioaddr + RTC_DATE_ALARM);
153	writeb(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ?
154	       0x80 : bin2bcd(pdata->alrm_hour),
155	       ioaddr + RTC_HOURS_ALARM);
156	writeb(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ?
157	       0x80 : bin2bcd(pdata->alrm_min),
158	       ioaddr + RTC_MINUTES_ALARM);
159	writeb(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ?
160	       0x80 : bin2bcd(pdata->alrm_sec),
161	       ioaddr + RTC_SECONDS_ALARM);
162	writeb(pdata->irqen ? RTC_INTS_AIE : 0, ioaddr + RTC_INTERRUPTS);
163	readb(ioaddr + RTC_FLAGS);	/* clear interrupts */
164	writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS);
165	spin_unlock_irqrestore(&pdata->lock, irqflags);
166}
167
168static int stk17ta8_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
169{
170	struct platform_device *pdev = to_platform_device(dev);
171	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
172
173	if (pdata->irq <= 0)
174		return -EINVAL;
175	pdata->alrm_mday = alrm->time.tm_mday;
176	pdata->alrm_hour = alrm->time.tm_hour;
177	pdata->alrm_min = alrm->time.tm_min;
178	pdata->alrm_sec = alrm->time.tm_sec;
179	if (alrm->enabled)
180		pdata->irqen |= RTC_AF;
181	stk17ta8_rtc_update_alarm(pdata);
182	return 0;
183}
184
185static int stk17ta8_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
186{
187	struct platform_device *pdev = to_platform_device(dev);
188	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
189
190	if (pdata->irq <= 0)
191		return -EINVAL;
192	alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
193	alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
194	alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
195	alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
196	alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
197	return 0;
198}
199
200static irqreturn_t stk17ta8_rtc_interrupt(int irq, void *dev_id)
201{
202	struct platform_device *pdev = dev_id;
203	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
204	void __iomem *ioaddr = pdata->ioaddr;
205	unsigned long events = 0;
206
207	spin_lock(&pdata->lock);
208	/* read and clear interrupt */
209	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF) {
210		events = RTC_IRQF;
211		if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80)
212			events |= RTC_UF;
213		else
214			events |= RTC_AF;
215		rtc_update_irq(pdata->rtc, 1, events);
 
216	}
217	spin_unlock(&pdata->lock);
218	return events ? IRQ_HANDLED : IRQ_NONE;
219}
220
221static int stk17ta8_rtc_alarm_irq_enable(struct device *dev,
222	unsigned int enabled)
223{
224	struct platform_device *pdev = to_platform_device(dev);
225	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
226
227	if (pdata->irq <= 0)
228		return -EINVAL;
229	if (enabled)
230		pdata->irqen |= RTC_AF;
231	else
232		pdata->irqen &= ~RTC_AF;
233	stk17ta8_rtc_update_alarm(pdata);
234	return 0;
235}
236
237static const struct rtc_class_ops stk17ta8_rtc_ops = {
238	.read_time		= stk17ta8_rtc_read_time,
239	.set_time		= stk17ta8_rtc_set_time,
240	.read_alarm		= stk17ta8_rtc_read_alarm,
241	.set_alarm		= stk17ta8_rtc_set_alarm,
242	.alarm_irq_enable	= stk17ta8_rtc_alarm_irq_enable,
243};
244
245static ssize_t stk17ta8_nvram_read(struct file *filp, struct kobject *kobj,
246				 struct bin_attribute *attr, char *buf,
247				 loff_t pos, size_t size)
248{
249	struct device *dev = container_of(kobj, struct device, kobj);
250	struct platform_device *pdev = to_platform_device(dev);
251	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
252	void __iomem *ioaddr = pdata->ioaddr;
253	ssize_t count;
254
255	for (count = 0; count < size; count++)
256		*buf++ = readb(ioaddr + pos++);
257	return count;
258}
259
260static ssize_t stk17ta8_nvram_write(struct file *filp, struct kobject *kobj,
261				  struct bin_attribute *attr, char *buf,
262				  loff_t pos, size_t size)
263{
264	struct device *dev = container_of(kobj, struct device, kobj);
265	struct platform_device *pdev = to_platform_device(dev);
266	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
267	void __iomem *ioaddr = pdata->ioaddr;
268	ssize_t count;
269
270	for (count = 0; count < size; count++)
271		writeb(*buf++, ioaddr + pos++);
272	return count;
273}
274
275static struct bin_attribute stk17ta8_nvram_attr = {
276	.attr = {
277		.name = "nvram",
278		.mode = S_IRUGO | S_IWUSR,
279	},
280	.size = RTC_OFFSET,
281	.read = stk17ta8_nvram_read,
282	.write = stk17ta8_nvram_write,
283};
284
285static int stk17ta8_rtc_probe(struct platform_device *pdev)
286{
287	struct resource *res;
288	unsigned int cal;
289	unsigned int flags;
290	struct rtc_plat_data *pdata;
291	void __iomem *ioaddr;
292	int ret = 0;
293
 
 
 
 
294	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
295	if (!pdata)
296		return -ENOMEM;
297
298	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
299	ioaddr = devm_ioremap_resource(&pdev->dev, res);
300	if (IS_ERR(ioaddr))
301		return PTR_ERR(ioaddr);
 
302	pdata->ioaddr = ioaddr;
303	pdata->irq = platform_get_irq(pdev, 0);
304
305	/* turn RTC on if it was not on */
306	cal = readb(ioaddr + RTC_CALIBRATION);
307	if (cal & RTC_STOP) {
308		cal &= RTC_CAL_MASK;
309		flags = readb(ioaddr + RTC_FLAGS);
310		writeb(flags | RTC_WRITE, ioaddr + RTC_FLAGS);
311		writeb(cal, ioaddr + RTC_CALIBRATION);
312		writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS);
313	}
314	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_PF)
315		dev_warn(&pdev->dev, "voltage-low detected.\n");
316
317	spin_lock_init(&pdata->lock);
318	pdata->last_jiffies = jiffies;
319	platform_set_drvdata(pdev, pdata);
320	if (pdata->irq > 0) {
321		writeb(0, ioaddr + RTC_INTERRUPTS);
322		if (devm_request_irq(&pdev->dev, pdata->irq,
323				stk17ta8_rtc_interrupt,
324				IRQF_SHARED,
325				pdev->name, pdev) < 0) {
326			dev_warn(&pdev->dev, "interrupt not available.\n");
327			pdata->irq = 0;
328		}
329	}
330
331	pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
332				  &stk17ta8_rtc_ops, THIS_MODULE);
333	if (IS_ERR(pdata->rtc))
334		return PTR_ERR(pdata->rtc);
335
336	ret = sysfs_create_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr);
337
 
338	return ret;
339}
340
341static int stk17ta8_rtc_remove(struct platform_device *pdev)
342{
343	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
344
345	sysfs_remove_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr);
 
346	if (pdata->irq > 0)
347		writeb(0, pdata->ioaddr + RTC_INTERRUPTS);
348	return 0;
349}
350
351/* work with hotplug and coldplug */
352MODULE_ALIAS("platform:stk17ta8");
353
354static struct platform_driver stk17ta8_rtc_driver = {
355	.probe		= stk17ta8_rtc_probe,
356	.remove		= stk17ta8_rtc_remove,
357	.driver		= {
358		.name	= "stk17ta8",
 
359	},
360};
361
362module_platform_driver(stk17ta8_rtc_driver);
 
 
 
 
 
 
 
 
 
 
 
363
364MODULE_AUTHOR("Thomas Hommel <thomas.hommel@ge.com>");
365MODULE_DESCRIPTION("Simtek STK17TA8 RTC driver");
366MODULE_LICENSE("GPL");
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);