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
26 static struct resource *puv3_rtc_mem;
27
28 static int puv3_rtc_alarmno = IRQ_RTCAlarm;
29 static int puv3_rtc_tickno = IRQ_RTC;
30
31 static DEFINE_SPINLOCK(puv3_rtc_pie_lock);
32
33 /* IRQ Handlers */
puv3_rtc_alarmirq(int irq,void * id)34 static 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
puv3_rtc_tickirq(int irq,void * id)43 static 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 */
puv3_rtc_setaie(struct device * dev,int to)53 static 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
puv3_rtc_setpie(struct device * dev,int enabled)67 static 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 */
puv3_rtc_gettime(struct device * dev,struct rtc_time * rtc_tm)86 static 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
puv3_rtc_settime(struct device * dev,struct rtc_time * tm)95 static 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
puv3_rtc_getalarm(struct device * dev,struct rtc_wkalrm * alrm)107 static 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
puv3_rtc_setalarm(struct device * dev,struct rtc_wkalrm * alrm)120 static 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
puv3_rtc_proc(struct device * dev,struct seq_file * seq)140 static 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
147 static 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
puv3_rtc_enable(struct device * dev,int en)155 static 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
puv3_rtc_remove(struct platform_device * dev)168 static 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
puv3_rtc_probe(struct platform_device * pdev)179 static 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
257 static int ticnt_save;
258
puv3_rtc_suspend(struct device * dev)259 static 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
puv3_rtc_resume(struct device * dev)267 static 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
275 static SIMPLE_DEV_PM_OPS(puv3_rtc_pm_ops, puv3_rtc_suspend, puv3_rtc_resume);
276
277 static 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
286 module_platform_driver(puv3_rtc_driver);
287
288 MODULE_DESCRIPTION("RTC Driver for the PKUnity v3 chip");
289 MODULE_AUTHOR("Hu Dongliang");
290 MODULE_LICENSE("GPL v2");
291