Root/drivers/rtc/rtc-stk17ta8.c

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        if (likely(pdata->rtc))
218            rtc_update_irq(pdata->rtc, 1, events);
219    }
220    spin_unlock(&pdata->lock);
221    return events ? IRQ_HANDLED : IRQ_NONE;
222}
223
224static int stk17ta8_rtc_alarm_irq_enable(struct device *dev,
225    unsigned int enabled)
226{
227    struct platform_device *pdev = to_platform_device(dev);
228    struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
229
230    if (pdata->irq <= 0)
231        return -EINVAL;
232    if (enabled)
233        pdata->irqen |= RTC_AF;
234    else
235        pdata->irqen &= ~RTC_AF;
236    stk17ta8_rtc_update_alarm(pdata);
237    return 0;
238}
239
240static const struct rtc_class_ops stk17ta8_rtc_ops = {
241    .read_time = stk17ta8_rtc_read_time,
242    .set_time = stk17ta8_rtc_set_time,
243    .read_alarm = stk17ta8_rtc_read_alarm,
244    .set_alarm = stk17ta8_rtc_set_alarm,
245    .alarm_irq_enable = stk17ta8_rtc_alarm_irq_enable,
246};
247
248static ssize_t stk17ta8_nvram_read(struct file *filp, struct kobject *kobj,
249                 struct bin_attribute *attr, char *buf,
250                 loff_t pos, size_t size)
251{
252    struct device *dev = container_of(kobj, struct device, kobj);
253    struct platform_device *pdev = to_platform_device(dev);
254    struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
255    void __iomem *ioaddr = pdata->ioaddr;
256    ssize_t count;
257
258    for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
259        *buf++ = readb(ioaddr + pos++);
260    return count;
261}
262
263static ssize_t stk17ta8_nvram_write(struct file *filp, struct kobject *kobj,
264                  struct bin_attribute *attr, char *buf,
265                  loff_t pos, size_t size)
266{
267    struct device *dev = container_of(kobj, struct device, kobj);
268    struct platform_device *pdev = to_platform_device(dev);
269    struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
270    void __iomem *ioaddr = pdata->ioaddr;
271    ssize_t count;
272
273    for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
274        writeb(*buf++, ioaddr + pos++);
275    return count;
276}
277
278static struct bin_attribute stk17ta8_nvram_attr = {
279    .attr = {
280        .name = "nvram",
281        .mode = S_IRUGO | S_IWUSR,
282    },
283    .size = RTC_OFFSET,
284    .read = stk17ta8_nvram_read,
285    .write = stk17ta8_nvram_write,
286};
287
288static int __devinit stk17ta8_rtc_probe(struct platform_device *pdev)
289{
290    struct resource *res;
291    unsigned int cal;
292    unsigned int flags;
293    struct rtc_plat_data *pdata;
294    void __iomem *ioaddr;
295    int ret = 0;
296
297    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
298    if (!res)
299        return -ENODEV;
300
301    pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
302    if (!pdata)
303        return -ENOMEM;
304    if (!devm_request_mem_region(&pdev->dev, res->start, RTC_REG_SIZE,
305            pdev->name))
306        return -EBUSY;
307    ioaddr = devm_ioremap(&pdev->dev, res->start, RTC_REG_SIZE);
308    if (!ioaddr)
309        return -ENOMEM;
310    pdata->ioaddr = ioaddr;
311    pdata->irq = platform_get_irq(pdev, 0);
312
313    /* turn RTC on if it was not on */
314    cal = readb(ioaddr + RTC_CALIBRATION);
315    if (cal & RTC_STOP) {
316        cal &= RTC_CAL_MASK;
317        flags = readb(ioaddr + RTC_FLAGS);
318        writeb(flags | RTC_WRITE, ioaddr + RTC_FLAGS);
319        writeb(cal, ioaddr + RTC_CALIBRATION);
320        writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS);
321    }
322    if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_PF)
323        dev_warn(&pdev->dev, "voltage-low detected.\n");
324
325    spin_lock_init(&pdata->lock);
326    pdata->last_jiffies = jiffies;
327    platform_set_drvdata(pdev, pdata);
328    if (pdata->irq > 0) {
329        writeb(0, ioaddr + RTC_INTERRUPTS);
330        if (devm_request_irq(&pdev->dev, pdata->irq,
331                stk17ta8_rtc_interrupt,
332                IRQF_SHARED,
333                pdev->name, pdev) < 0) {
334            dev_warn(&pdev->dev, "interrupt not available.\n");
335            pdata->irq = 0;
336        }
337    }
338
339    pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
340                  &stk17ta8_rtc_ops, THIS_MODULE);
341    if (IS_ERR(pdata->rtc))
342        return PTR_ERR(pdata->rtc);
343
344    ret = sysfs_create_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr);
345    if (ret)
346        rtc_device_unregister(pdata->rtc);
347    return ret;
348}
349
350static int __devexit stk17ta8_rtc_remove(struct platform_device *pdev)
351{
352    struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
353
354    sysfs_remove_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr);
355    rtc_device_unregister(pdata->rtc);
356    if (pdata->irq > 0)
357        writeb(0, pdata->ioaddr + RTC_INTERRUPTS);
358    return 0;
359}
360
361/* work with hotplug and coldplug */
362MODULE_ALIAS("platform:stk17ta8");
363
364static struct platform_driver stk17ta8_rtc_driver = {
365    .probe = stk17ta8_rtc_probe,
366    .remove = __devexit_p(stk17ta8_rtc_remove),
367    .driver = {
368        .name = "stk17ta8",
369        .owner = THIS_MODULE,
370    },
371};
372
373module_platform_driver(stk17ta8_rtc_driver);
374
375MODULE_AUTHOR("Thomas Hommel <thomas.hommel@ge.com>");
376MODULE_DESCRIPTION("Simtek STK17TA8 RTC driver");
377MODULE_LICENSE("GPL");
378MODULE_VERSION(DRV_VERSION);
379

Archive Download this file

Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master

Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9



interactive