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
 29static struct resource *puv3_rtc_mem;
 30
 31static int puv3_rtc_alarmno = IRQ_RTCAlarm;
 32static int puv3_rtc_tickno  = IRQ_RTC;
 33
 34static DEFINE_SPINLOCK(puv3_rtc_pie_lock);
 35
 36/* IRQ Handlers */
 37static 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
 46static 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 */
 56static void puv3_rtc_setaie(struct device *dev, int to)
 57{
 58	unsigned int tmp;
 59
 60	dev_dbg(dev, "%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
 70static int puv3_rtc_setpie(struct device *dev, int enabled)
 71{
 72	unsigned int tmp;
 73
 74	dev_dbg(dev, "%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 */
 89static 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	dev_dbg(dev, "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
100static int puv3_rtc_settime(struct device *dev, struct rtc_time *tm)
101{
102	unsigned long rtc_count = 0;
103
104	dev_dbg(dev, "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
114static 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	dev_dbg(dev, "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
130static 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	dev_dbg(dev, "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(dev, 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
153static 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
160static 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
189static 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
200static 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
210static 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
223static int puv3_rtc_remove(struct platform_device *dev)
224{
225	struct rtc_device *rtc = platform_get_drvdata(dev);
226
227	rtc_device_unregister(rtc);
228
229	puv3_rtc_setpie(&dev->dev, 0);
230	puv3_rtc_setaie(&dev->dev, 0);
231
232	release_resource(puv3_rtc_mem);
233	kfree(puv3_rtc_mem);
234
235	return 0;
236}
237
238static int puv3_rtc_probe(struct platform_device *pdev)
239{
240	struct rtc_device *rtc;
241	struct resource *res;
242	int ret;
243
244	dev_dbg(&pdev->dev, "%s: probe=%p\n", __func__, pdev);
245
246	/* find the IRQs */
247	puv3_rtc_tickno = platform_get_irq(pdev, 1);
248	if (puv3_rtc_tickno < 0) {
249		dev_err(&pdev->dev, "no irq for rtc tick\n");
250		return -ENOENT;
251	}
252
253	puv3_rtc_alarmno = platform_get_irq(pdev, 0);
254	if (puv3_rtc_alarmno < 0) {
255		dev_err(&pdev->dev, "no irq for alarm\n");
256		return -ENOENT;
257	}
258
259	dev_dbg(&pdev->dev, "PKUnity_rtc: tick irq %d, alarm irq %d\n",
260		 puv3_rtc_tickno, puv3_rtc_alarmno);
261
262	/* get the memory region */
263	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
264	if (res == NULL) {
265		dev_err(&pdev->dev, "failed to get memory region resource\n");
266		return -ENOENT;
267	}
268
269	puv3_rtc_mem = request_mem_region(res->start, resource_size(res),
270					  pdev->name);
271
272	if (puv3_rtc_mem == NULL) {
273		dev_err(&pdev->dev, "failed to reserve memory region\n");
274		ret = -ENOENT;
275		goto err_nores;
276	}
277
278	puv3_rtc_enable(&pdev->dev, 1);
279
280	/* register RTC and exit */
281	rtc = rtc_device_register("pkunity", &pdev->dev, &puv3_rtcops,
282				  THIS_MODULE);
283
284	if (IS_ERR(rtc)) {
285		dev_err(&pdev->dev, "cannot attach rtc\n");
286		ret = PTR_ERR(rtc);
287		goto err_nortc;
288	}
289
290	/* platform setup code should have handled this; sigh */
291	if (!device_can_wakeup(&pdev->dev))
292		device_init_wakeup(&pdev->dev, 1);
293
294	platform_set_drvdata(pdev, rtc);
295	return 0;
296
297 err_nortc:
298	puv3_rtc_enable(&pdev->dev, 0);
299	release_resource(puv3_rtc_mem);
300
301 err_nores:
302	return ret;
303}
304
305#ifdef CONFIG_PM_SLEEP
306static int ticnt_save;
307
308static int puv3_rtc_suspend(struct device *dev)
309{
310	/* save RTAR for anyone using periodic interrupts */
311	ticnt_save = readl(RTC_RTAR);
312	puv3_rtc_enable(dev, 0);
313	return 0;
314}
315
316static int puv3_rtc_resume(struct device *dev)
317{
318	puv3_rtc_enable(dev, 1);
319	writel(ticnt_save, RTC_RTAR);
320	return 0;
321}
322#endif
323
324static SIMPLE_DEV_PM_OPS(puv3_rtc_pm_ops, puv3_rtc_suspend, puv3_rtc_resume);
325
326static struct platform_driver puv3_rtc_driver = {
327	.probe		= puv3_rtc_probe,
328	.remove		= puv3_rtc_remove,
329	.driver		= {
330		.name	= "PKUnity-v3-RTC",
331		.pm	= &puv3_rtc_pm_ops,
332	}
333};
334
335module_platform_driver(puv3_rtc_driver);
336
337MODULE_DESCRIPTION("RTC Driver for the PKUnity v3 chip");
338MODULE_AUTHOR("Hu Dongliang");
339MODULE_LICENSE("GPL v2");