aboutsummaryrefslogtreecommitdiff
path: root/drivers/rtc/rtc-puv3.c
blob: 402732cfb32a5574f6fda08f5637ba04a6d1fb0d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
/*
 * RTC driver code specific to PKUnity SoC and UniCore ISA
 *
 *	Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn>
 *	Copyright (C) 2001-2010 Guan Xuetao
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/clk.h>
#include <linux/log2.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/io.h>

#include <asm/irq.h>
#include <mach/hardware.h>

static struct resource *puv3_rtc_mem;

static int puv3_rtc_alarmno = IRQ_RTCAlarm;
static int puv3_rtc_tickno  = IRQ_RTC;

static DEFINE_SPINLOCK(puv3_rtc_pie_lock);

/* IRQ Handlers */
static irqreturn_t puv3_rtc_alarmirq(int irq, void *id)
{
	struct rtc_device *rdev = id;

	writel(readl(RTC_RTSR) | RTC_RTSR_AL, RTC_RTSR);
	rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF);
	return IRQ_HANDLED;
}

static irqreturn_t puv3_rtc_tickirq(int irq, void *id)
{
	struct rtc_device *rdev = id;

	writel(readl(RTC_RTSR) | RTC_RTSR_HZ, RTC_RTSR);
	rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF);
	return IRQ_HANDLED;
}

/* Update control registers */
static void puv3_rtc_setaie(int to)
{
	unsigned int tmp;

	pr_debug("%s: aie=%d\n", __func__, to);

	tmp = readl(RTC_RTSR) & ~RTC_RTSR_ALE;

	if (to)
		tmp |= RTC_RTSR_ALE;

	writel(tmp, RTC_RTSR);
}

static int puv3_rtc_setpie(struct device *dev, int enabled)
{
	unsigned int tmp;

	pr_debug("%s: pie=%d\n", __func__, enabled);

	spin_lock_irq(&puv3_rtc_pie_lock);
	tmp = readl(RTC_RTSR) & ~RTC_RTSR_HZE;

	if (enabled)
		tmp |= RTC_RTSR_HZE;

	writel(tmp, RTC_RTSR);
	spin_unlock_irq(&puv3_rtc_pie_lock);

	return 0;
}

/* Time read/write */
static int puv3_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
{
	rtc_time_to_tm(readl(RTC_RCNR), rtc_tm);

	pr_debug("read time %02x.%02x.%02x %02x/%02x/%02x\n",
		 rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
		 rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);

	return 0;
}

static int puv3_rtc_settime(struct device *dev, struct rtc_time *tm)
{
	unsigned long rtc_count = 0;

	pr_debug("set time %02d.%02d.%02d %02d/%02d/%02d\n",
		 tm->tm_year, tm->tm_mon, tm->tm_mday,
		 tm->tm_hour, tm->tm_min, tm->tm_sec);

	rtc_tm_to_time(tm, &rtc_count);
	writel(rtc_count, RTC_RCNR);

	return 0;
}

static int puv3_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct rtc_time *alm_tm = &alrm->time;

	rtc_time_to_tm(readl(RTC_RTAR), alm_tm);

	alrm->enabled = readl(RTC_RTSR) & RTC_RTSR_ALE;

	pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
		 alrm->enabled,
		 alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
		 alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);

	return 0;
}

static int puv3_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct rtc_time *tm = &alrm->time;
	unsigned long rtcalarm_count = 0;

	pr_debug("puv3_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n",
		 alrm->enabled,
		 tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff,
		 tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec);

	rtc_tm_to_time(tm, &rtcalarm_count);
	writel(rtcalarm_count, RTC_RTAR);

	puv3_rtc_setaie(alrm->enabled);

	if (alrm->enabled)
		enable_irq_wake(puv3_rtc_alarmno);
	else
		disable_irq_wake(puv3_rtc_alarmno);

	return 0;
}

static int puv3_rtc_proc(struct device *dev, struct seq_file *seq)
{
	seq_printf(seq, "periodic_IRQ\t: %s\n",
		     (readl(RTC_RTSR) & RTC_RTSR_HZE) ? "yes" : "no");
	return 0;
}

static int puv3_rtc_open(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
	int ret;

	ret = request_irq(puv3_rtc_alarmno, puv3_rtc_alarmirq,
			0, "pkunity-rtc alarm", rtc_dev);

	if (ret) {
		dev_err(dev, "IRQ%d error %d\n", puv3_rtc_alarmno, ret);
		return ret;
	}

	ret = request_irq(puv3_rtc_tickno, puv3_rtc_tickirq,
			0, "pkunity-rtc tick", rtc_dev);

	if (ret) {
		dev_err(dev, "IRQ%d error %d\n", puv3_rtc_tickno, ret);
		goto tick_err;
	}

	return ret;

 tick_err:
	free_irq(puv3_rtc_alarmno, rtc_dev);
	return ret;
}

static void puv3_rtc_release(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct rtc_device *rtc_dev = platform_get_drvdata(pdev);

	/* do not clear AIE here, it may be needed for wake */
	puv3_rtc_setpie(dev, 0);
	free_irq(puv3_rtc_alarmno, rtc_dev);
	free_irq(puv3_rtc_tickno, rtc_dev);
}

static const struct rtc_class_ops puv3_rtcops = {
	.open		= puv3_rtc_open,
	.release	= puv3_rtc_release,
	.read_time	= puv3_rtc_gettime,
	.set_time	= puv3_rtc_settime,
	.read_alarm	= puv3_rtc_getalarm,
	.set_alarm	= puv3_rtc_setalarm,
	.proc	        = puv3_rtc_proc,
};

static void puv3_rtc_enable(struct device *dev, int en)
{
	if (!en) {
		writel(readl(RTC_RTSR) & ~RTC_RTSR_HZE, RTC_RTSR);
	} else {
		/* re-enable the device, and check it is ok */
		if ((readl(RTC_RTSR) & RTC_RTSR_HZE) == 0) {
			dev_info(dev, "rtc disabled, re-enabling\n");
			writel(readl(RTC_RTSR) | RTC_RTSR_HZE, RTC_RTSR);
		}
	}
}

static int puv3_rtc_remove(struct platform_device *dev)
{
	struct rtc_device *rtc = platform_get_drvdata(dev);

	rtc_device_unregister(rtc);

	puv3_rtc_setpie(&dev->dev, 0);
	puv3_rtc_setaie(0);

	release_resource(puv3_rtc_mem);
	kfree(puv3_rtc_mem);

	return 0;
}

static int puv3_rtc_probe(struct platform_device *pdev)
{
	struct rtc_device *rtc;
	struct resource *res;
	int ret;

	pr_debug("%s: probe=%p\n", __func__, pdev);

	/* find the IRQs */
	puv3_rtc_tickno = platform_get_irq(pdev, 1);
	if (puv3_rtc_tickno < 0) {
		dev_err(&pdev->dev, "no irq for rtc tick\n");
		return -ENOENT;
	}

	puv3_rtc_alarmno = platform_get_irq(pdev, 0);
	if (puv3_rtc_alarmno < 0) {
		dev_err(&pdev->dev, "no irq for alarm\n");
		return -ENOENT;
	}

	pr_debug("PKUnity_rtc: tick irq %d, alarm irq %d\n",
		 puv3_rtc_tickno, puv3_rtc_alarmno);

	/* get the memory region */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (res == NULL) {
		dev_err(&pdev->dev, "failed to get memory region resource\n");
		return -ENOENT;
	}

	puv3_rtc_mem = request_mem_region(res->start, resource_size(res),
					  pdev->name);

	if (puv3_rtc_mem == NULL) {
		dev_err(&pdev->dev, "failed to reserve memory region\n");
		ret = -ENOENT;
		goto err_nores;
	}

	puv3_rtc_enable(&pdev->dev, 1);

	/* register RTC and exit */
	rtc = rtc_device_register("pkunity", &pdev->dev, &puv3_rtcops,
				  THIS_MODULE);

	if (IS_ERR(rtc)) {
		dev_err(&pdev->dev, "cannot attach rtc\n");
		ret = PTR_ERR(rtc);
		goto err_nortc;
	}

	/* platform setup code should have handled this; sigh */
	if (!device_can_wakeup(&pdev->dev))
		device_init_wakeup(&pdev->dev, 1);

	platform_set_drvdata(pdev, rtc);
	return 0;

 err_nortc:
	puv3_rtc_enable(&pdev->dev, 0);
	release_resource(puv3_rtc_mem);

 err_nores:
	return ret;
}

#ifdef CONFIG_PM_SLEEP
static int ticnt_save;

static int puv3_rtc_suspend(struct device *dev)
{
	/* save RTAR for anyone using periodic interrupts */
	ticnt_save = readl(RTC_RTAR);
	puv3_rtc_enable(dev, 0);
	return 0;
}

static int puv3_rtc_resume(struct device *dev)
{
	puv3_rtc_enable(dev, 1);
	writel(ticnt_save, RTC_RTAR);
	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(puv3_rtc_pm_ops, puv3_rtc_suspend, puv3_rtc_resume);

static struct platform_driver puv3_rtc_driver = {
	.probe		= puv3_rtc_probe,
	.remove		= puv3_rtc_remove,
	.driver		= {
		.name	= "PKUnity-v3-RTC",
		.owner	= THIS_MODULE,
		.pm	= &puv3_rtc_pm_ops,
	}
};

module_platform_driver(puv3_rtc_driver);

MODULE_DESCRIPTION("RTC Driver for the PKUnity v3 chip");
MODULE_AUTHOR("Hu Dongliang");
MODULE_LICENSE("GPL v2");