1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * RTC driver code specific to PKUnity SoC and UniCore ISA
  4 *
  5 *	Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn>
  6 *	Copyright (C) 2001-2010 Guan Xuetao
  7 */
  8
  9#include <linux/module.h>
 10#include <linux/fs.h>
 11#include <linux/string.h>
 12#include <linux/init.h>
 13#include <linux/platform_device.h>
 14#include <linux/interrupt.h>
 15#include <linux/rtc.h>
 16#include <linux/bcd.h>
 17#include <linux/clk.h>
 18#include <linux/log2.h>
 19#include <linux/slab.h>
 20#include <linux/uaccess.h>
 21#include <linux/io.h>
 22
 23#include <asm/irq.h>
 24#include <mach/hardware.h>
 25
 26static struct resource *puv3_rtc_mem;
 27
 28static int puv3_rtc_alarmno = IRQ_RTCAlarm;
 29static int puv3_rtc_tickno  = IRQ_RTC;
 30
 31static DEFINE_SPINLOCK(puv3_rtc_pie_lock);
 32
 33/* IRQ Handlers */
 34static irqreturn_t puv3_rtc_alarmirq(int irq, void *id)
 35{
 36	struct rtc_device *rdev = id;
 37
 38	writel(readl(RTC_RTSR) | RTC_RTSR_AL, RTC_RTSR);
 39	rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF);
 40	return IRQ_HANDLED;
 41}
 42
 43static irqreturn_t puv3_rtc_tickirq(int irq, void *id)
 44{
 45	struct rtc_device *rdev = id;
 46
 47	writel(readl(RTC_RTSR) | RTC_RTSR_HZ, RTC_RTSR);
 48	rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF);
 49	return IRQ_HANDLED;
 50}
 51
 52/* Update control registers */
 53static void puv3_rtc_setaie(struct device *dev, int to)
 54{
 55	unsigned int tmp;
 56
 57	dev_dbg(dev, "%s: aie=%d\n", __func__, to);
 58
 59	tmp = readl(RTC_RTSR) & ~RTC_RTSR_ALE;
 60
 61	if (to)
 62		tmp |= RTC_RTSR_ALE;
 63
 64	writel(tmp, RTC_RTSR);
 65}
 66
 67static int puv3_rtc_setpie(struct device *dev, int enabled)
 68{
 69	unsigned int tmp;
 70
 71	dev_dbg(dev, "%s: pie=%d\n", __func__, enabled);
 72
 73	spin_lock_irq(&puv3_rtc_pie_lock);
 74	tmp = readl(RTC_RTSR) & ~RTC_RTSR_HZE;
 75
 76	if (enabled)
 77		tmp |= RTC_RTSR_HZE;
 78
 79	writel(tmp, RTC_RTSR);
 80	spin_unlock_irq(&puv3_rtc_pie_lock);
 81
 82	return 0;
 83}
 84
 85/* Time read/write */
 86static int puv3_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
 87{
 88	rtc_time_to_tm(readl(RTC_RCNR), rtc_tm);
 89
 90	dev_dbg(dev, "read time %ptRr\n", rtc_tm);
 91
 92	return 0;
 93}
 94
 95static int puv3_rtc_settime(struct device *dev, struct rtc_time *tm)
 96{
 97	unsigned long rtc_count = 0;
 98
 99	dev_dbg(dev, "set time %ptRr\n", tm);
100
101	rtc_tm_to_time(tm, &rtc_count);
102	writel(rtc_count, RTC_RCNR);
103
104	return 0;
105}
106
107static int puv3_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
108{
109	struct rtc_time *alm_tm = &alrm->time;
110
111	rtc_time_to_tm(readl(RTC_RTAR), alm_tm);
112
113	alrm->enabled = readl(RTC_RTSR) & RTC_RTSR_ALE;
114
115	dev_dbg(dev, "read alarm: %d, %ptRr\n", alrm->enabled, alm_tm);
116
117	return 0;
118}
119
120static int puv3_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
121{
122	struct rtc_time *tm = &alrm->time;
123	unsigned long rtcalarm_count = 0;
124
125	dev_dbg(dev, "set alarm: %d, %ptRr\n", alrm->enabled, tm);
126
127	rtc_tm_to_time(tm, &rtcalarm_count);
128	writel(rtcalarm_count, RTC_RTAR);
129
130	puv3_rtc_setaie(dev, alrm->enabled);
131
132	if (alrm->enabled)
133		enable_irq_wake(puv3_rtc_alarmno);
134	else
135		disable_irq_wake(puv3_rtc_alarmno);
136
137	return 0;
138}
139
140static int puv3_rtc_proc(struct device *dev, struct seq_file *seq)
141{
142	seq_printf(seq, "periodic_IRQ\t: %s\n",
143		     (readl(RTC_RTSR) & RTC_RTSR_HZE) ? "yes" : "no");
144	return 0;
145}
146
147static const struct rtc_class_ops puv3_rtcops = {
148	.read_time	= puv3_rtc_gettime,
149	.set_time	= puv3_rtc_settime,
150	.read_alarm	= puv3_rtc_getalarm,
151	.set_alarm	= puv3_rtc_setalarm,
152	.proc	        = puv3_rtc_proc,
153};
154
155static void puv3_rtc_enable(struct device *dev, int en)
156{
157	if (!en) {
158		writel(readl(RTC_RTSR) & ~RTC_RTSR_HZE, RTC_RTSR);
159	} else {
160		/* re-enable the device, and check it is ok */
161		if ((readl(RTC_RTSR) & RTC_RTSR_HZE) == 0) {
162			dev_info(dev, "rtc disabled, re-enabling\n");
163			writel(readl(RTC_RTSR) | RTC_RTSR_HZE, RTC_RTSR);
164		}
165	}
166}
167
168static int puv3_rtc_remove(struct platform_device *dev)
169{
170	puv3_rtc_setpie(&dev->dev, 0);
171	puv3_rtc_setaie(&dev->dev, 0);
172
173	release_resource(puv3_rtc_mem);
174	kfree(puv3_rtc_mem);
175
176	return 0;
177}
178
179static int puv3_rtc_probe(struct platform_device *pdev)
180{
181	struct rtc_device *rtc;
182	struct resource *res;
183	int ret;
184
185	dev_dbg(&pdev->dev, "%s: probe=%p\n", __func__, pdev);
186
187	/* find the IRQs */
188	puv3_rtc_tickno = platform_get_irq(pdev, 1);
189	if (puv3_rtc_tickno < 0)
190		return -ENOENT;
191
192	puv3_rtc_alarmno = platform_get_irq(pdev, 0);
193	if (puv3_rtc_alarmno < 0)
194		return -ENOENT;
195
196	dev_dbg(&pdev->dev, "PKUnity_rtc: tick irq %d, alarm irq %d\n",
197		 puv3_rtc_tickno, puv3_rtc_alarmno);
198
199	rtc = devm_rtc_allocate_device(&pdev->dev);
200	if (IS_ERR(rtc))
201		return PTR_ERR(rtc);
202
203	ret = devm_request_irq(&pdev->dev, puv3_rtc_alarmno, puv3_rtc_alarmirq,
204			       0, "pkunity-rtc alarm", rtc);
205	if (ret) {
206		dev_err(&pdev->dev, "IRQ%d error %d\n", puv3_rtc_alarmno, ret);
207		return ret;
208	}
209
210	ret = devm_request_irq(&pdev->dev, puv3_rtc_tickno, puv3_rtc_tickirq,
211			       0, "pkunity-rtc tick", rtc);
212	if (ret) {
213		dev_err(&pdev->dev, "IRQ%d error %d\n", puv3_rtc_tickno, ret);
214		return ret;
215	}
216
217	/* get the memory region */
218	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
219	if (res == NULL) {
220		dev_err(&pdev->dev, "failed to get memory region resource\n");
221		return -ENOENT;
222	}
223
224	puv3_rtc_mem = request_mem_region(res->start, resource_size(res),
225					  pdev->name);
226
227	if (puv3_rtc_mem == NULL) {
228		dev_err(&pdev->dev, "failed to reserve memory region\n");
229		ret = -ENOENT;
230		goto err_nores;
231	}
232
233	puv3_rtc_enable(&pdev->dev, 1);
234
235	/* register RTC and exit */
236	rtc->ops = &puv3_rtcops;
237	ret = rtc_register_device(rtc);
238	if (ret)
239		goto err_nortc;
240
241	/* platform setup code should have handled this; sigh */
242	if (!device_can_wakeup(&pdev->dev))
243		device_init_wakeup(&pdev->dev, 1);
244
245	platform_set_drvdata(pdev, rtc);
246	return 0;
247
248 err_nortc:
249	puv3_rtc_enable(&pdev->dev, 0);
250	release_resource(puv3_rtc_mem);
251
252 err_nores:
253	return ret;
254}
255
256#ifdef CONFIG_PM_SLEEP
257static int ticnt_save;
258
259static int puv3_rtc_suspend(struct device *dev)
260{
261	/* save RTAR for anyone using periodic interrupts */
262	ticnt_save = readl(RTC_RTAR);
263	puv3_rtc_enable(dev, 0);
264	return 0;
265}
266
267static int puv3_rtc_resume(struct device *dev)
268{
269	puv3_rtc_enable(dev, 1);
270	writel(ticnt_save, RTC_RTAR);
271	return 0;
272}
273#endif
274
275static SIMPLE_DEV_PM_OPS(puv3_rtc_pm_ops, puv3_rtc_suspend, puv3_rtc_resume);
276
277static struct platform_driver puv3_rtc_driver = {
278	.probe		= puv3_rtc_probe,
279	.remove		= puv3_rtc_remove,
280	.driver		= {
281		.name	= "PKUnity-v3-RTC",
282		.pm	= &puv3_rtc_pm_ops,
283	}
284};
285
286module_platform_driver(puv3_rtc_driver);
287
288MODULE_DESCRIPTION("RTC Driver for the PKUnity v3 chip");
289MODULE_AUTHOR("Hu Dongliang");
290MODULE_LICENSE("GPL v2");