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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
53#define RTC_STOP 0x80
54
55
56#define RTC_FLAGS_AF 0x40
57#define RTC_FLAGS_PF 0x20
58#define RTC_WRITE 0x02
59#define RTC_READ 0x01
60
61
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
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
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);
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
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; 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 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
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
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 .owner = THIS_MODULE,
362 },
363};
364
365module_platform_driver(stk17ta8_rtc_driver);
366
367MODULE_AUTHOR("Thomas Hommel <thomas.hommel@ge.com>");
368MODULE_DESCRIPTION("Simtek STK17TA8 RTC driver");
369MODULE_LICENSE("GPL");
370MODULE_VERSION(DRV_VERSION);
371
