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 const struct rtc_class_ops puv3_rtcops = {
161	.read_time	= puv3_rtc_gettime,
162	.set_time	= puv3_rtc_settime,
163	.read_alarm	= puv3_rtc_getalarm,
164	.set_alarm	= puv3_rtc_setalarm,
165	.proc	        = puv3_rtc_proc,
166};
167
168static void puv3_rtc_enable(struct device *dev, int en)
169{
170	if (!en) {
171		writel(readl(RTC_RTSR) & ~RTC_RTSR_HZE, RTC_RTSR);
172	} else {
173		/* re-enable the device, and check it is ok */
174		if ((readl(RTC_RTSR) & RTC_RTSR_HZE) == 0) {
175			dev_info(dev, "rtc disabled, re-enabling\n");
176			writel(readl(RTC_RTSR) | RTC_RTSR_HZE, RTC_RTSR);
177		}
178	}
179}
180
181static int puv3_rtc_remove(struct platform_device *dev)
182{
183	puv3_rtc_setpie(&dev->dev, 0);
184	puv3_rtc_setaie(&dev->dev, 0);
185
186	release_resource(puv3_rtc_mem);
187	kfree(puv3_rtc_mem);
188
189	return 0;
190}
191
192static int puv3_rtc_probe(struct platform_device *pdev)
193{
194	struct rtc_device *rtc;
195	struct resource *res;
196	int ret;
197
198	dev_dbg(&pdev->dev, "%s: probe=%p\n", __func__, pdev);
199
200	/* find the IRQs */
201	puv3_rtc_tickno = platform_get_irq(pdev, 1);
202	if (puv3_rtc_tickno < 0) {
203		dev_err(&pdev->dev, "no irq for rtc tick\n");
204		return -ENOENT;
205	}
206
207	puv3_rtc_alarmno = platform_get_irq(pdev, 0);
208	if (puv3_rtc_alarmno < 0) {
209		dev_err(&pdev->dev, "no irq for alarm\n");
210		return -ENOENT;
211	}
212
213	dev_dbg(&pdev->dev, "PKUnity_rtc: tick irq %d, alarm irq %d\n",
214		 puv3_rtc_tickno, puv3_rtc_alarmno);
215
216	rtc = devm_rtc_allocate_device(&pdev->dev);
217	if (IS_ERR(rtc))
218		return PTR_ERR(rtc);
219
220	ret = devm_request_irq(&pdev->dev, puv3_rtc_alarmno, puv3_rtc_alarmirq,
221			       0, "pkunity-rtc alarm", rtc);
222	if (ret) {
223		dev_err(&pdev->dev, "IRQ%d error %d\n", puv3_rtc_alarmno, ret);
224		return ret;
225	}
226
227	ret = devm_request_irq(&pdev->dev, puv3_rtc_tickno, puv3_rtc_tickirq,
228			       0, "pkunity-rtc tick", rtc);
229	if (ret) {
230		dev_err(&pdev->dev, "IRQ%d error %d\n", puv3_rtc_tickno, ret);
231		return ret;
232	}
233
234	/* get the memory region */
235	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
236	if (res == NULL) {
237		dev_err(&pdev->dev, "failed to get memory region resource\n");
238		return -ENOENT;
239	}
240
241	puv3_rtc_mem = request_mem_region(res->start, resource_size(res),
242					  pdev->name);
243
244	if (puv3_rtc_mem == NULL) {
245		dev_err(&pdev->dev, "failed to reserve memory region\n");
246		ret = -ENOENT;
247		goto err_nores;
248	}
249
250	puv3_rtc_enable(&pdev->dev, 1);
251
252	/* register RTC and exit */
253	rtc->ops = &puv3_rtcops;
254	ret = rtc_register_device(rtc);
255	if (ret) {
256		dev_err(&pdev->dev, "cannot attach rtc\n");
257		goto err_nortc;
258	}
259
260	/* platform setup code should have handled this; sigh */
261	if (!device_can_wakeup(&pdev->dev))
262		device_init_wakeup(&pdev->dev, 1);
263
264	platform_set_drvdata(pdev, rtc);
265	return 0;
266
267 err_nortc:
268	puv3_rtc_enable(&pdev->dev, 0);
269	release_resource(puv3_rtc_mem);
270
271 err_nores:
272	return ret;
273}
274
275#ifdef CONFIG_PM_SLEEP
276static int ticnt_save;
277
278static int puv3_rtc_suspend(struct device *dev)
279{
280	/* save RTAR for anyone using periodic interrupts */
281	ticnt_save = readl(RTC_RTAR);
282	puv3_rtc_enable(dev, 0);
283	return 0;
284}
285
286static int puv3_rtc_resume(struct device *dev)
287{
288	puv3_rtc_enable(dev, 1);
289	writel(ticnt_save, RTC_RTAR);
290	return 0;
291}
292#endif
293
294static SIMPLE_DEV_PM_OPS(puv3_rtc_pm_ops, puv3_rtc_suspend, puv3_rtc_resume);
295
296static struct platform_driver puv3_rtc_driver = {
297	.probe		= puv3_rtc_probe,
298	.remove		= puv3_rtc_remove,
299	.driver		= {
300		.name	= "PKUnity-v3-RTC",
301		.pm	= &puv3_rtc_pm_ops,
302	}
303};
304
305module_platform_driver(puv3_rtc_driver);
306
307MODULE_DESCRIPTION("RTC Driver for the PKUnity v3 chip");
308MODULE_AUTHOR("Hu Dongliang");
309MODULE_LICENSE("GPL v2");