blob: 2e16f72c90569fdb0fe6e26b16f6257e1604de2b [file] [log] [blame]
Lars-Peter Clausen3bf0eea2010-06-19 18:29:50 +00001/*
2 * Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
Paul Cercueild0f744c2010-10-27 15:33:12 -07003 * Copyright (C) 2010, Paul Cercueil <paul@crapouillou.net>
Lars-Peter Clausen3bf0eea2010-06-19 18:29:50 +00004 * JZ4740 SoC RTC driver
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * option) any later version.
10 *
11 * You should have received a copy of the GNU General Public License along
12 * with this program; if not, write to the Free Software Foundation, Inc.,
13 * 675 Mass Ave, Cambridge, MA 02139, USA.
14 *
15 */
16
17#include <linux/kernel.h>
18#include <linux/module.h>
19#include <linux/platform_device.h>
20#include <linux/rtc.h>
21#include <linux/slab.h>
22#include <linux/spinlock.h>
23
24#define JZ_REG_RTC_CTRL 0x00
25#define JZ_REG_RTC_SEC 0x04
26#define JZ_REG_RTC_SEC_ALARM 0x08
27#define JZ_REG_RTC_REGULATOR 0x0C
28#define JZ_REG_RTC_HIBERNATE 0x20
29#define JZ_REG_RTC_SCRATCHPAD 0x34
30
31#define JZ_RTC_CTRL_WRDY BIT(7)
32#define JZ_RTC_CTRL_1HZ BIT(6)
33#define JZ_RTC_CTRL_1HZ_IRQ BIT(5)
34#define JZ_RTC_CTRL_AF BIT(4)
35#define JZ_RTC_CTRL_AF_IRQ BIT(3)
36#define JZ_RTC_CTRL_AE BIT(2)
37#define JZ_RTC_CTRL_ENABLE BIT(0)
38
39struct jz4740_rtc {
40 struct resource *mem;
41 void __iomem *base;
42
43 struct rtc_device *rtc;
44
45 unsigned int irq;
46
47 spinlock_t lock;
48};
49
50static inline uint32_t jz4740_rtc_reg_read(struct jz4740_rtc *rtc, size_t reg)
51{
52 return readl(rtc->base + reg);
53}
54
55static int jz4740_rtc_wait_write_ready(struct jz4740_rtc *rtc)
56{
57 uint32_t ctrl;
58 int timeout = 1000;
59
60 do {
61 ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
62 } while (!(ctrl & JZ_RTC_CTRL_WRDY) && --timeout);
63
64 return timeout ? 0 : -EIO;
65}
66
67static inline int jz4740_rtc_reg_write(struct jz4740_rtc *rtc, size_t reg,
68 uint32_t val)
69{
70 int ret;
71 ret = jz4740_rtc_wait_write_ready(rtc);
72 if (ret == 0)
73 writel(val, rtc->base + reg);
74
75 return ret;
76}
77
78static int jz4740_rtc_ctrl_set_bits(struct jz4740_rtc *rtc, uint32_t mask,
79 bool set)
80{
81 int ret;
82 unsigned long flags;
83 uint32_t ctrl;
84
85 spin_lock_irqsave(&rtc->lock, flags);
86
87 ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
88
89 /* Don't clear interrupt flags by accident */
90 ctrl |= JZ_RTC_CTRL_1HZ | JZ_RTC_CTRL_AF;
91
92 if (set)
93 ctrl |= mask;
94 else
95 ctrl &= ~mask;
96
97 ret = jz4740_rtc_reg_write(rtc, JZ_REG_RTC_CTRL, ctrl);
98
99 spin_unlock_irqrestore(&rtc->lock, flags);
100
101 return ret;
102}
103
104static int jz4740_rtc_read_time(struct device *dev, struct rtc_time *time)
105{
106 struct jz4740_rtc *rtc = dev_get_drvdata(dev);
107 uint32_t secs, secs2;
108 int timeout = 5;
109
110 /* If the seconds register is read while it is updated, it can contain a
111 * bogus value. This can be avoided by making sure that two consecutive
112 * reads have the same value.
113 */
114 secs = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC);
115 secs2 = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC);
116
117 while (secs != secs2 && --timeout) {
118 secs = secs2;
119 secs2 = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC);
120 }
121
122 if (timeout == 0)
123 return -EIO;
124
125 rtc_time_to_tm(secs, time);
126
127 return rtc_valid_tm(time);
128}
129
130static int jz4740_rtc_set_mmss(struct device *dev, unsigned long secs)
131{
132 struct jz4740_rtc *rtc = dev_get_drvdata(dev);
133
134 return jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SEC, secs);
135}
136
137static int jz4740_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
138{
139 struct jz4740_rtc *rtc = dev_get_drvdata(dev);
140 uint32_t secs;
141 uint32_t ctrl;
142
143 secs = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC_ALARM);
144
145 ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
146
147 alrm->enabled = !!(ctrl & JZ_RTC_CTRL_AE);
148 alrm->pending = !!(ctrl & JZ_RTC_CTRL_AF);
149
150 rtc_time_to_tm(secs, &alrm->time);
151
152 return rtc_valid_tm(&alrm->time);
153}
154
155static int jz4740_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
156{
157 int ret;
158 struct jz4740_rtc *rtc = dev_get_drvdata(dev);
159 unsigned long secs;
160
161 rtc_tm_to_time(&alrm->time, &secs);
162
163 ret = jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SEC_ALARM, secs);
164 if (!ret)
Paul Cercueild0f744c2010-10-27 15:33:12 -0700165 ret = jz4740_rtc_ctrl_set_bits(rtc,
166 JZ_RTC_CTRL_AE | JZ_RTC_CTRL_AF_IRQ, alrm->enabled);
Lars-Peter Clausen3bf0eea2010-06-19 18:29:50 +0000167
168 return ret;
169}
170
171static int jz4740_rtc_update_irq_enable(struct device *dev, unsigned int enable)
172{
173 struct jz4740_rtc *rtc = dev_get_drvdata(dev);
174 return jz4740_rtc_ctrl_set_bits(rtc, JZ_RTC_CTRL_1HZ_IRQ, enable);
175}
176
177static int jz4740_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
178{
179 struct jz4740_rtc *rtc = dev_get_drvdata(dev);
180 return jz4740_rtc_ctrl_set_bits(rtc, JZ_RTC_CTRL_AF_IRQ, enable);
181}
182
183static struct rtc_class_ops jz4740_rtc_ops = {
184 .read_time = jz4740_rtc_read_time,
185 .set_mmss = jz4740_rtc_set_mmss,
186 .read_alarm = jz4740_rtc_read_alarm,
187 .set_alarm = jz4740_rtc_set_alarm,
188 .update_irq_enable = jz4740_rtc_update_irq_enable,
189 .alarm_irq_enable = jz4740_rtc_alarm_irq_enable,
190};
191
192static irqreturn_t jz4740_rtc_irq(int irq, void *data)
193{
194 struct jz4740_rtc *rtc = data;
195 uint32_t ctrl;
196 unsigned long events = 0;
197
198 ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
199
200 if (ctrl & JZ_RTC_CTRL_1HZ)
201 events |= (RTC_UF | RTC_IRQF);
202
203 if (ctrl & JZ_RTC_CTRL_AF)
204 events |= (RTC_AF | RTC_IRQF);
205
206 rtc_update_irq(rtc->rtc, 1, events);
207
208 jz4740_rtc_ctrl_set_bits(rtc, JZ_RTC_CTRL_1HZ | JZ_RTC_CTRL_AF, false);
209
210 return IRQ_HANDLED;
211}
212
213void jz4740_rtc_poweroff(struct device *dev)
214{
215 struct jz4740_rtc *rtc = dev_get_drvdata(dev);
216 jz4740_rtc_reg_write(rtc, JZ_REG_RTC_HIBERNATE, 1);
217}
218EXPORT_SYMBOL_GPL(jz4740_rtc_poweroff);
219
220static int __devinit jz4740_rtc_probe(struct platform_device *pdev)
221{
222 int ret;
223 struct jz4740_rtc *rtc;
224 uint32_t scratchpad;
225
226 rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);
227 if (!rtc)
228 return -ENOMEM;
229
230 rtc->irq = platform_get_irq(pdev, 0);
231 if (rtc->irq < 0) {
232 ret = -ENOENT;
233 dev_err(&pdev->dev, "Failed to get platform irq\n");
234 goto err_free;
235 }
236
237 rtc->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
238 if (!rtc->mem) {
239 ret = -ENOENT;
240 dev_err(&pdev->dev, "Failed to get platform mmio memory\n");
241 goto err_free;
242 }
243
244 rtc->mem = request_mem_region(rtc->mem->start, resource_size(rtc->mem),
245 pdev->name);
246 if (!rtc->mem) {
247 ret = -EBUSY;
248 dev_err(&pdev->dev, "Failed to request mmio memory region\n");
249 goto err_free;
250 }
251
252 rtc->base = ioremap_nocache(rtc->mem->start, resource_size(rtc->mem));
253 if (!rtc->base) {
254 ret = -EBUSY;
255 dev_err(&pdev->dev, "Failed to ioremap mmio memory\n");
256 goto err_release_mem_region;
257 }
258
259 spin_lock_init(&rtc->lock);
260
261 platform_set_drvdata(pdev, rtc);
262
Paul Cercueild0f744c2010-10-27 15:33:12 -0700263 device_init_wakeup(&pdev->dev, 1);
264
Lars-Peter Clausen3bf0eea2010-06-19 18:29:50 +0000265 rtc->rtc = rtc_device_register(pdev->name, &pdev->dev, &jz4740_rtc_ops,
266 THIS_MODULE);
267 if (IS_ERR(rtc->rtc)) {
268 ret = PTR_ERR(rtc->rtc);
269 dev_err(&pdev->dev, "Failed to register rtc device: %d\n", ret);
270 goto err_iounmap;
271 }
272
273 ret = request_irq(rtc->irq, jz4740_rtc_irq, 0,
274 pdev->name, rtc);
275 if (ret) {
276 dev_err(&pdev->dev, "Failed to request rtc irq: %d\n", ret);
277 goto err_unregister_rtc;
278 }
279
280 scratchpad = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SCRATCHPAD);
281 if (scratchpad != 0x12345678) {
282 ret = jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SCRATCHPAD, 0x12345678);
283 ret = jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SEC, 0);
284 if (ret) {
285 dev_err(&pdev->dev, "Could not write write to RTC registers\n");
286 goto err_free_irq;
287 }
288 }
289
290 return 0;
291
292err_free_irq:
293 free_irq(rtc->irq, rtc);
294err_unregister_rtc:
295 rtc_device_unregister(rtc->rtc);
296err_iounmap:
297 platform_set_drvdata(pdev, NULL);
298 iounmap(rtc->base);
299err_release_mem_region:
300 release_mem_region(rtc->mem->start, resource_size(rtc->mem));
301err_free:
302 kfree(rtc);
303
304 return ret;
305}
306
307static int __devexit jz4740_rtc_remove(struct platform_device *pdev)
308{
309 struct jz4740_rtc *rtc = platform_get_drvdata(pdev);
310
311 free_irq(rtc->irq, rtc);
312
313 rtc_device_unregister(rtc->rtc);
314
315 iounmap(rtc->base);
316 release_mem_region(rtc->mem->start, resource_size(rtc->mem));
317
318 kfree(rtc);
319
320 platform_set_drvdata(pdev, NULL);
321
322 return 0;
323}
324
Paul Cercueild0f744c2010-10-27 15:33:12 -0700325
326#ifdef CONFIG_PM
327static int jz4740_rtc_suspend(struct device *dev)
328{
329 struct jz4740_rtc *rtc = dev_get_drvdata(dev);
330
331 if (device_may_wakeup(dev))
332 enable_irq_wake(rtc->irq);
333 return 0;
334}
335
336static int jz4740_rtc_resume(struct device *dev)
337{
338 struct jz4740_rtc *rtc = dev_get_drvdata(dev);
339
340 if (device_may_wakeup(dev))
341 disable_irq_wake(rtc->irq);
342 return 0;
343}
344
345static const struct dev_pm_ops jz4740_pm_ops = {
346 .suspend = jz4740_rtc_suspend,
347 .resume = jz4740_rtc_resume,
348};
349#define JZ4740_RTC_PM_OPS (&jz4740_pm_ops)
350
351#else
352#define JZ4740_RTC_PM_OPS NULL
353#endif /* CONFIG_PM */
354
Lars-Peter Clausen3bf0eea2010-06-19 18:29:50 +0000355struct platform_driver jz4740_rtc_driver = {
Paul Cercueild0f744c2010-10-27 15:33:12 -0700356 .probe = jz4740_rtc_probe,
357 .remove = __devexit_p(jz4740_rtc_remove),
358 .driver = {
359 .name = "jz4740-rtc",
Lars-Peter Clausen3bf0eea2010-06-19 18:29:50 +0000360 .owner = THIS_MODULE,
Paul Cercueild0f744c2010-10-27 15:33:12 -0700361 .pm = JZ4740_RTC_PM_OPS,
Lars-Peter Clausen3bf0eea2010-06-19 18:29:50 +0000362 },
363};
364
365static int __init jz4740_rtc_init(void)
366{
367 return platform_driver_register(&jz4740_rtc_driver);
368}
369module_init(jz4740_rtc_init);
370
371static void __exit jz4740_rtc_exit(void)
372{
373 platform_driver_unregister(&jz4740_rtc_driver);
374}
375module_exit(jz4740_rtc_exit);
376
377MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
378MODULE_LICENSE("GPL");
379MODULE_DESCRIPTION("RTC driver for the JZ4740 SoC\n");
380MODULE_ALIAS("platform:jz4740-rtc");