tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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_time64_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 dev_dbg(dev, "set time %ptRr\n", tm);
98
99 writel(rtc_tm_to_time64(tm), RTC_RCNR);
100
101 return 0;
102}
103
104static int puv3_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
105{
106 struct rtc_time *alm_tm = &alrm->time;
107
108 rtc_time64_to_tm(readl(RTC_RTAR), alm_tm);
109
110 alrm->enabled = readl(RTC_RTSR) & RTC_RTSR_ALE;
111
112 dev_dbg(dev, "read alarm: %d, %ptRr\n", alrm->enabled, alm_tm);
113
114 return 0;
115}
116
117static int puv3_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
118{
119 struct rtc_time *tm = &alrm->time;
120
121 dev_dbg(dev, "set alarm: %d, %ptRr\n", alrm->enabled, tm);
122
123 writel(rtc_tm_to_time64(tm), RTC_RTAR);
124
125 puv3_rtc_setaie(dev, alrm->enabled);
126
127 if (alrm->enabled)
128 enable_irq_wake(puv3_rtc_alarmno);
129 else
130 disable_irq_wake(puv3_rtc_alarmno);
131
132 return 0;
133}
134
135static int puv3_rtc_proc(struct device *dev, struct seq_file *seq)
136{
137 seq_printf(seq, "periodic_IRQ\t: %s\n",
138 (readl(RTC_RTSR) & RTC_RTSR_HZE) ? "yes" : "no");
139 return 0;
140}
141
142static const struct rtc_class_ops puv3_rtcops = {
143 .read_time = puv3_rtc_gettime,
144 .set_time = puv3_rtc_settime,
145 .read_alarm = puv3_rtc_getalarm,
146 .set_alarm = puv3_rtc_setalarm,
147 .proc = puv3_rtc_proc,
148};
149
150static void puv3_rtc_enable(struct device *dev, int en)
151{
152 if (!en) {
153 writel(readl(RTC_RTSR) & ~RTC_RTSR_HZE, RTC_RTSR);
154 } else {
155 /* re-enable the device, and check it is ok */
156 if ((readl(RTC_RTSR) & RTC_RTSR_HZE) == 0) {
157 dev_info(dev, "rtc disabled, re-enabling\n");
158 writel(readl(RTC_RTSR) | RTC_RTSR_HZE, RTC_RTSR);
159 }
160 }
161}
162
163static int puv3_rtc_remove(struct platform_device *dev)
164{
165 puv3_rtc_setpie(&dev->dev, 0);
166 puv3_rtc_setaie(&dev->dev, 0);
167
168 release_resource(puv3_rtc_mem);
169 kfree(puv3_rtc_mem);
170
171 return 0;
172}
173
174static int puv3_rtc_probe(struct platform_device *pdev)
175{
176 struct rtc_device *rtc;
177 struct resource *res;
178 int ret;
179
180 dev_dbg(&pdev->dev, "%s: probe=%p\n", __func__, pdev);
181
182 /* find the IRQs */
183 puv3_rtc_tickno = platform_get_irq(pdev, 1);
184 if (puv3_rtc_tickno < 0)
185 return -ENOENT;
186
187 puv3_rtc_alarmno = platform_get_irq(pdev, 0);
188 if (puv3_rtc_alarmno < 0)
189 return -ENOENT;
190
191 dev_dbg(&pdev->dev, "PKUnity_rtc: tick irq %d, alarm irq %d\n",
192 puv3_rtc_tickno, puv3_rtc_alarmno);
193
194 rtc = devm_rtc_allocate_device(&pdev->dev);
195 if (IS_ERR(rtc))
196 return PTR_ERR(rtc);
197
198 ret = devm_request_irq(&pdev->dev, puv3_rtc_alarmno, puv3_rtc_alarmirq,
199 0, "pkunity-rtc alarm", rtc);
200 if (ret) {
201 dev_err(&pdev->dev, "IRQ%d error %d\n", puv3_rtc_alarmno, ret);
202 return ret;
203 }
204
205 ret = devm_request_irq(&pdev->dev, puv3_rtc_tickno, puv3_rtc_tickirq,
206 0, "pkunity-rtc tick", rtc);
207 if (ret) {
208 dev_err(&pdev->dev, "IRQ%d error %d\n", puv3_rtc_tickno, ret);
209 return ret;
210 }
211
212 /* get the memory region */
213 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
214 if (res == NULL) {
215 dev_err(&pdev->dev, "failed to get memory region resource\n");
216 return -ENOENT;
217 }
218
219 puv3_rtc_mem = request_mem_region(res->start, resource_size(res),
220 pdev->name);
221
222 if (puv3_rtc_mem == NULL) {
223 dev_err(&pdev->dev, "failed to reserve memory region\n");
224 ret = -ENOENT;
225 goto err_nores;
226 }
227
228 puv3_rtc_enable(&pdev->dev, 1);
229
230 /* register RTC and exit */
231 rtc->ops = &puv3_rtcops;
232 rtc->range_max = U32_MAX;
233 ret = rtc_register_device(rtc);
234 if (ret)
235 goto err_nortc;
236
237 /* platform setup code should have handled this; sigh */
238 if (!device_can_wakeup(&pdev->dev))
239 device_init_wakeup(&pdev->dev, 1);
240
241 platform_set_drvdata(pdev, rtc);
242 return 0;
243
244 err_nortc:
245 puv3_rtc_enable(&pdev->dev, 0);
246 release_resource(puv3_rtc_mem);
247
248 err_nores:
249 return ret;
250}
251
252#ifdef CONFIG_PM_SLEEP
253static int ticnt_save;
254
255static int puv3_rtc_suspend(struct device *dev)
256{
257 /* save RTAR for anyone using periodic interrupts */
258 ticnt_save = readl(RTC_RTAR);
259 puv3_rtc_enable(dev, 0);
260 return 0;
261}
262
263static int puv3_rtc_resume(struct device *dev)
264{
265 puv3_rtc_enable(dev, 1);
266 writel(ticnt_save, RTC_RTAR);
267 return 0;
268}
269#endif
270
271static SIMPLE_DEV_PM_OPS(puv3_rtc_pm_ops, puv3_rtc_suspend, puv3_rtc_resume);
272
273static struct platform_driver puv3_rtc_driver = {
274 .probe = puv3_rtc_probe,
275 .remove = puv3_rtc_remove,
276 .driver = {
277 .name = "PKUnity-v3-RTC",
278 .pm = &puv3_rtc_pm_ops,
279 }
280};
281
282module_platform_driver(puv3_rtc_driver);
283
284MODULE_DESCRIPTION("RTC Driver for the PKUnity v3 chip");
285MODULE_AUTHOR("Hu Dongliang");
286MODULE_LICENSE("GPL v2");