1 /*
2 * RTC driver code specific to PKUnity SoC and UniCore ISA
3 *
4 * Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn>
5 * Copyright (C) 2001-2010 Guan Xuetao
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12 #include <linux/module.h>
13 #include <linux/fs.h>
14 #include <linux/string.h>
15 #include <linux/init.h>
16 #include <linux/platform_device.h>
17 #include <linux/interrupt.h>
18 #include <linux/rtc.h>
19 #include <linux/bcd.h>
20 #include <linux/clk.h>
21 #include <linux/log2.h>
22 #include <linux/slab.h>
23 #include <linux/uaccess.h>
24 #include <linux/io.h>
25
26 #include <asm/irq.h>
27 #include <mach/hardware.h>
28
29 static struct resource *puv3_rtc_mem;
30
31 static int puv3_rtc_alarmno = IRQ_RTCAlarm;
32 static int puv3_rtc_tickno = IRQ_RTC;
33
34 static DEFINE_SPINLOCK(puv3_rtc_pie_lock);
35
36 /* IRQ Handlers */
puv3_rtc_alarmirq(int irq,void * id)37 static irqreturn_t puv3_rtc_alarmirq(int irq, void *id)
38 {
39 struct rtc_device *rdev = id;
40
41 writel(readl(RTC_RTSR) | RTC_RTSR_AL, RTC_RTSR);
42 rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF);
43 return IRQ_HANDLED;
44 }
45
puv3_rtc_tickirq(int irq,void * id)46 static irqreturn_t puv3_rtc_tickirq(int irq, void *id)
47 {
48 struct rtc_device *rdev = id;
49
50 writel(readl(RTC_RTSR) | RTC_RTSR_HZ, RTC_RTSR);
51 rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF);
52 return IRQ_HANDLED;
53 }
54
55 /* Update control registers */
puv3_rtc_setaie(int to)56 static void puv3_rtc_setaie(int to)
57 {
58 unsigned int tmp;
59
60 pr_debug("%s: aie=%d\n", __func__, to);
61
62 tmp = readl(RTC_RTSR) & ~RTC_RTSR_ALE;
63
64 if (to)
65 tmp |= RTC_RTSR_ALE;
66
67 writel(tmp, RTC_RTSR);
68 }
69
puv3_rtc_setpie(struct device * dev,int enabled)70 static int puv3_rtc_setpie(struct device *dev, int enabled)
71 {
72 unsigned int tmp;
73
74 pr_debug("%s: pie=%d\n", __func__, enabled);
75
76 spin_lock_irq(&puv3_rtc_pie_lock);
77 tmp = readl(RTC_RTSR) & ~RTC_RTSR_HZE;
78
79 if (enabled)
80 tmp |= RTC_RTSR_HZE;
81
82 writel(tmp, RTC_RTSR);
83 spin_unlock_irq(&puv3_rtc_pie_lock);
84
85 return 0;
86 }
87
88 /* Time read/write */
puv3_rtc_gettime(struct device * dev,struct rtc_time * rtc_tm)89 static int puv3_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
90 {
91 rtc_time_to_tm(readl(RTC_RCNR), rtc_tm);
92
93 pr_debug("read time %02x.%02x.%02x %02x/%02x/%02x\n",
94 rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
95 rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
96
97 return 0;
98 }
99
puv3_rtc_settime(struct device * dev,struct rtc_time * tm)100 static int puv3_rtc_settime(struct device *dev, struct rtc_time *tm)
101 {
102 unsigned long rtc_count = 0;
103
104 pr_debug("set time %02d.%02d.%02d %02d/%02d/%02d\n",
105 tm->tm_year, tm->tm_mon, tm->tm_mday,
106 tm->tm_hour, tm->tm_min, tm->tm_sec);
107
108 rtc_tm_to_time(tm, &rtc_count);
109 writel(rtc_count, RTC_RCNR);
110
111 return 0;
112 }
113
puv3_rtc_getalarm(struct device * dev,struct rtc_wkalrm * alrm)114 static int puv3_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
115 {
116 struct rtc_time *alm_tm = &alrm->time;
117
118 rtc_time_to_tm(readl(RTC_RTAR), alm_tm);
119
120 alrm->enabled = readl(RTC_RTSR) & RTC_RTSR_ALE;
121
122 pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
123 alrm->enabled,
124 alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
125 alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
126
127 return 0;
128 }
129
puv3_rtc_setalarm(struct device * dev,struct rtc_wkalrm * alrm)130 static int puv3_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
131 {
132 struct rtc_time *tm = &alrm->time;
133 unsigned long rtcalarm_count = 0;
134
135 pr_debug("puv3_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n",
136 alrm->enabled,
137 tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff,
138 tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec);
139
140 rtc_tm_to_time(tm, &rtcalarm_count);
141 writel(rtcalarm_count, RTC_RTAR);
142
143 puv3_rtc_setaie(alrm->enabled);
144
145 if (alrm->enabled)
146 enable_irq_wake(puv3_rtc_alarmno);
147 else
148 disable_irq_wake(puv3_rtc_alarmno);
149
150 return 0;
151 }
152
puv3_rtc_proc(struct device * dev,struct seq_file * seq)153 static int puv3_rtc_proc(struct device *dev, struct seq_file *seq)
154 {
155 seq_printf(seq, "periodic_IRQ\t: %s\n",
156 (readl(RTC_RTSR) & RTC_RTSR_HZE) ? "yes" : "no");
157 return 0;
158 }
159
puv3_rtc_open(struct device * dev)160 static int puv3_rtc_open(struct device *dev)
161 {
162 struct platform_device *pdev = to_platform_device(dev);
163 struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
164 int ret;
165
166 ret = request_irq(puv3_rtc_alarmno, puv3_rtc_alarmirq,
167 0, "pkunity-rtc alarm", rtc_dev);
168
169 if (ret) {
170 dev_err(dev, "IRQ%d error %d\n", puv3_rtc_alarmno, ret);
171 return ret;
172 }
173
174 ret = request_irq(puv3_rtc_tickno, puv3_rtc_tickirq,
175 0, "pkunity-rtc tick", rtc_dev);
176
177 if (ret) {
178 dev_err(dev, "IRQ%d error %d\n", puv3_rtc_tickno, ret);
179 goto tick_err;
180 }
181
182 return ret;
183
184 tick_err:
185 free_irq(puv3_rtc_alarmno, rtc_dev);
186 return ret;
187 }
188
puv3_rtc_release(struct device * dev)189 static void puv3_rtc_release(struct device *dev)
190 {
191 struct platform_device *pdev = to_platform_device(dev);
192 struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
193
194 /* do not clear AIE here, it may be needed for wake */
195 puv3_rtc_setpie(dev, 0);
196 free_irq(puv3_rtc_alarmno, rtc_dev);
197 free_irq(puv3_rtc_tickno, rtc_dev);
198 }
199
200 static const struct rtc_class_ops puv3_rtcops = {
201 .open = puv3_rtc_open,
202 .release = puv3_rtc_release,
203 .read_time = puv3_rtc_gettime,
204 .set_time = puv3_rtc_settime,
205 .read_alarm = puv3_rtc_getalarm,
206 .set_alarm = puv3_rtc_setalarm,
207 .proc = puv3_rtc_proc,
208 };
209
puv3_rtc_enable(struct device * dev,int en)210 static void puv3_rtc_enable(struct device *dev, int en)
211 {
212 if (!en) {
213 writel(readl(RTC_RTSR) & ~RTC_RTSR_HZE, RTC_RTSR);
214 } else {
215 /* re-enable the device, and check it is ok */
216 if ((readl(RTC_RTSR) & RTC_RTSR_HZE) == 0) {
217 dev_info(dev, "rtc disabled, re-enabling\n");
218 writel(readl(RTC_RTSR) | RTC_RTSR_HZE, RTC_RTSR);
219 }
220 }
221 }
222
puv3_rtc_remove(struct platform_device * dev)223 static int puv3_rtc_remove(struct platform_device *dev)
224 {
225 struct rtc_device *rtc = platform_get_drvdata(dev);
226
227 platform_set_drvdata(dev, NULL);
228 rtc_device_unregister(rtc);
229
230 puv3_rtc_setpie(&dev->dev, 0);
231 puv3_rtc_setaie(0);
232
233 release_resource(puv3_rtc_mem);
234 kfree(puv3_rtc_mem);
235
236 return 0;
237 }
238
puv3_rtc_probe(struct platform_device * pdev)239 static int puv3_rtc_probe(struct platform_device *pdev)
240 {
241 struct rtc_device *rtc;
242 struct resource *res;
243 int ret;
244
245 pr_debug("%s: probe=%p\n", __func__, pdev);
246
247 /* find the IRQs */
248 puv3_rtc_tickno = platform_get_irq(pdev, 1);
249 if (puv3_rtc_tickno < 0) {
250 dev_err(&pdev->dev, "no irq for rtc tick\n");
251 return -ENOENT;
252 }
253
254 puv3_rtc_alarmno = platform_get_irq(pdev, 0);
255 if (puv3_rtc_alarmno < 0) {
256 dev_err(&pdev->dev, "no irq for alarm\n");
257 return -ENOENT;
258 }
259
260 pr_debug("PKUnity_rtc: tick irq %d, alarm irq %d\n",
261 puv3_rtc_tickno, puv3_rtc_alarmno);
262
263 /* get the memory region */
264 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
265 if (res == NULL) {
266 dev_err(&pdev->dev, "failed to get memory region resource\n");
267 return -ENOENT;
268 }
269
270 puv3_rtc_mem = request_mem_region(res->start, resource_size(res),
271 pdev->name);
272
273 if (puv3_rtc_mem == NULL) {
274 dev_err(&pdev->dev, "failed to reserve memory region\n");
275 ret = -ENOENT;
276 goto err_nores;
277 }
278
279 puv3_rtc_enable(&pdev->dev, 1);
280
281 /* register RTC and exit */
282 rtc = rtc_device_register("pkunity", &pdev->dev, &puv3_rtcops,
283 THIS_MODULE);
284
285 if (IS_ERR(rtc)) {
286 dev_err(&pdev->dev, "cannot attach rtc\n");
287 ret = PTR_ERR(rtc);
288 goto err_nortc;
289 }
290
291 /* platform setup code should have handled this; sigh */
292 if (!device_can_wakeup(&pdev->dev))
293 device_init_wakeup(&pdev->dev, 1);
294
295 platform_set_drvdata(pdev, rtc);
296 return 0;
297
298 err_nortc:
299 puv3_rtc_enable(&pdev->dev, 0);
300 release_resource(puv3_rtc_mem);
301
302 err_nores:
303 return ret;
304 }
305
306 #ifdef CONFIG_PM_SLEEP
307 static int ticnt_save;
308
puv3_rtc_suspend(struct device * dev)309 static int puv3_rtc_suspend(struct device *dev)
310 {
311 /* save RTAR for anyone using periodic interrupts */
312 ticnt_save = readl(RTC_RTAR);
313 puv3_rtc_enable(dev, 0);
314 return 0;
315 }
316
puv3_rtc_resume(struct device * dev)317 static int puv3_rtc_resume(struct device *dev)
318 {
319 puv3_rtc_enable(dev, 1);
320 writel(ticnt_save, RTC_RTAR);
321 return 0;
322 }
323 #endif
324
325 static SIMPLE_DEV_PM_OPS(puv3_rtc_pm_ops, puv3_rtc_suspend, puv3_rtc_resume);
326
327 static struct platform_driver puv3_rtc_driver = {
328 .probe = puv3_rtc_probe,
329 .remove = puv3_rtc_remove,
330 .driver = {
331 .name = "PKUnity-v3-RTC",
332 .owner = THIS_MODULE,
333 .pm = &puv3_rtc_pm_ops,
334 }
335 };
336
337 module_platform_driver(puv3_rtc_driver);
338
339 MODULE_DESCRIPTION("RTC Driver for the PKUnity v3 chip");
340 MODULE_AUTHOR("Hu Dongliang");
341 MODULE_LICENSE("GPL v2");
342