1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
|
/*
* Copyright (C) 2009, Lars-Peter Clausen <lars@metafoo.de>
* JZ4720/JZ4740 SoC RTC driver
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <linux/rtc.h>
#define JZ_REG_RTC_CTRL 0x00
#define JZ_REG_RTC_SEC 0x04
#define JZ_REG_RTC_SEC_ALARM 0x08
#define JZ_REG_RTC_REGULATOR 0x0C
#define JZ_REG_RTC_SCRATCHPAD 0x34
#define JZ_RTC_CTRL_WRDY BIT(7)
#define JZ_RTC_CTRL_1HZ BIT(6)
#define JZ_RTC_CTRL_1HZ_IRQ BIT(5)
#define JZ_RTC_CTRL_AF BIT(4)
#define JZ_RTC_CTRL_AF_IRQ BIT(3)
#define JZ_RTC_CTRL_AE BIT(2)
#define JZ_RTC_CTRL_ENABLE BIT(0)
struct jz4740_rtc {
struct resource *mem;
void __iomem *base;
struct rtc_device *rtc;
unsigned int irq;
spinlock_t lock;
};
static inline uint32_t jz4740_rtc_reg_read(struct jz4740_rtc *rtc, size_t reg)
{
return readl(rtc->base + reg);
}
static inline void jz4740_rtc_wait_write_ready(struct jz4740_rtc *rtc)
{
uint32_t ctrl;
do {
ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
} while (!(ctrl & JZ_RTC_CTRL_WRDY));
}
static inline void jz4740_rtc_reg_write(struct jz4740_rtc *rtc, size_t reg,
uint32_t val)
{
jz4740_rtc_wait_write_ready(rtc);
writel(val, rtc->base + reg);
}
static void jz4740_rtc_ctrl_set_bits(struct jz4740_rtc *rtc, uint32_t mask,
uint32_t val)
{
unsigned long flags;
uint32_t ctrl;
spin_lock_irqsave(&rtc->lock, flags);
ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
/* Don't clear interrupt flags by accident */
ctrl |= JZ_RTC_CTRL_1HZ | JZ_RTC_CTRL_AF;
ctrl &= ~mask;
ctrl |= val;
jz4740_rtc_reg_write(rtc, JZ_REG_RTC_CTRL, ctrl);
spin_unlock_irqrestore(&rtc->lock, flags);
}
static inline struct jz4740_rtc *dev_to_rtc(struct device *dev)
{
return dev_get_drvdata(dev);
}
static int jz4740_rtc_read_time(struct device *dev, struct rtc_time *time)
{
struct jz4740_rtc *rtc = dev_to_rtc(dev);
uint32_t secs, secs2;
secs = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC);
secs2 = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC);
while (secs != secs2) {
secs = secs2;
secs2 = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC);
}
rtc_time_to_tm(secs, time);
return rtc_valid_tm(time);
}
static int jz4740_rtc_set_mmss(struct device *dev, unsigned long secs)
{
struct jz4740_rtc *rtc = dev_to_rtc(dev);
if ((uint32_t)secs != secs)
return -EINVAL;
jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SEC, secs);
return 0;
}
static int jz4740_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct jz4740_rtc *rtc = dev_to_rtc(dev);
uint32_t secs, secs2;
uint32_t ctrl;
secs = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC_ALARM);
secs2 = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC_ALARM);
while (secs != secs2){
secs = secs2;
secs2 = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC_ALARM);
}
ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
alrm->enabled = !!(ctrl & JZ_RTC_CTRL_AE);
alrm->pending = !!(ctrl & JZ_RTC_CTRL_AF);
rtc_time_to_tm(secs, &alrm->time);
return rtc_valid_tm(&alrm->time);
}
static int jz4740_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct jz4740_rtc *rtc = dev_to_rtc(dev);
unsigned long secs;
rtc_tm_to_time(&alrm->time, &secs);
if ((uint32_t)secs != secs)
return -EINVAL;
jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SEC_ALARM, (uint32_t)secs);
jz4740_rtc_ctrl_set_bits(rtc, JZ_RTC_CTRL_AE,
alrm->enabled ? JZ_RTC_CTRL_AE : 0);
return 0;
}
static int jz4740_rtc_update_irq_enable(struct device *dev, unsigned int enabled)
{
struct jz4740_rtc *rtc = dev_to_rtc(dev);
jz4740_rtc_ctrl_set_bits(rtc, JZ_RTC_CTRL_1HZ_IRQ,
enabled ? JZ_RTC_CTRL_1HZ_IRQ : 0);
return 0;
}
static int jz4740_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
struct jz4740_rtc *rtc = dev_to_rtc(dev);
jz4740_rtc_ctrl_set_bits(rtc, JZ_RTC_CTRL_AF_IRQ,
enabled ? JZ_RTC_CTRL_AF_IRQ : 0);
return 0;
}
static struct rtc_class_ops jz4740_rtc_ops = {
.read_time = jz4740_rtc_read_time,
.set_mmss = jz4740_rtc_set_mmss,
.read_alarm = jz4740_rtc_read_alarm,
.set_alarm = jz4740_rtc_set_alarm,
.update_irq_enable = jz4740_rtc_update_irq_enable,
.alarm_irq_enable = jz4740_rtc_alarm_irq_enable,
};
static irqreturn_t jz4740_rtc_irq(int irq, void *data)
{
struct jz4740_rtc *rtc = data;
uint32_t ctrl;
unsigned long events = 0;
ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
if (ctrl & JZ_RTC_CTRL_1HZ)
events |= (RTC_UF | RTC_IRQF);
if (ctrl & JZ_RTC_CTRL_AF)
events |= (RTC_AF | RTC_IRQF);
rtc_update_irq(rtc->rtc, 1, events);
jz4740_rtc_ctrl_set_bits(rtc, JZ_RTC_CTRL_1HZ | JZ_RTC_CTRL_AF, 0);
return IRQ_HANDLED;
}
static int __devinit jz4740_rtc_probe(struct platform_device *pdev)
{
int ret;
struct jz4740_rtc *rtc;
uint32_t scratchpad;
rtc = kmalloc(sizeof(*rtc), GFP_KERNEL);
rtc->irq = platform_get_irq(pdev, 0);
if (rtc->irq < 0) {
ret = -ENOENT;
dev_err(&pdev->dev, "Failed to get platform irq\n");
goto err_free;
}
rtc->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!rtc->mem) {
ret = -ENOENT;
dev_err(&pdev->dev, "Failed to get platform mmio memory\n");
goto err_free;
}
rtc->mem = request_mem_region(rtc->mem->start, resource_size(rtc->mem),
pdev->name);
if (!rtc->mem) {
ret = -EBUSY;
dev_err(&pdev->dev, "Failed to request mmio memory region\n");
goto err_free;
}
rtc->base = ioremap_nocache(rtc->mem->start, resource_size(rtc->mem));
if (!rtc->base) {
ret = -EBUSY;
dev_err(&pdev->dev, "Failed to ioremap mmio memory\n");
goto err_release_mem_region;
}
platform_set_drvdata(pdev, rtc);
rtc->rtc = rtc_device_register(pdev->name, &pdev->dev, &jz4740_rtc_ops,
THIS_MODULE);
if (IS_ERR(rtc->rtc)) {
ret = PTR_ERR(rtc->rtc);
dev_err(&pdev->dev, "Failed to register rtc device: %d\n", ret);
goto err_iounmap;
}
ret = request_irq(rtc->irq, jz4740_rtc_irq, 0,
pdev->name, rtc);
if (ret) {
dev_err(&pdev->dev, "Failed to request rtc irq: %d\n", ret);
goto err_unregister_rtc;
}
scratchpad = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SCRATCHPAD);
if (scratchpad != 0x12345678) {
jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SCRATCHPAD, 0x12345678);
jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SEC, 0);
}
return 0;
err_unregister_rtc:
rtc_device_unregister(rtc->rtc);
err_iounmap:
platform_set_drvdata(pdev, NULL);
iounmap(rtc->base);
err_release_mem_region:
release_mem_region(rtc->mem->start, resource_size(rtc->mem));
err_free:
kfree(rtc);
return ret;
}
static int __devexit jz4740_rtc_remove(struct platform_device *pdev)
{
struct jz4740_rtc *rtc = platform_get_drvdata(pdev);
rtc_device_unregister(rtc->rtc);
iounmap(rtc->base);
release_mem_region(rtc->mem->start, resource_size(rtc->mem));
kfree(rtc);
platform_set_drvdata(pdev, NULL);
return 0;
}
struct platform_driver jz4740_rtc_driver = {
.probe = jz4740_rtc_probe,
.remove = __devexit_p(jz4740_rtc_remove),
.driver = {
.name = "jz4740-rtc",
.owner = THIS_MODULE,
},
};
static int __init jz4740_rtc_init(void)
{
return platform_driver_register(&jz4740_rtc_driver);
}
module_init(jz4740_rtc_init);
static void __exit jz4740_rtc_exit(void)
{
platform_driver_unregister(&jz4740_rtc_driver);
}
module_exit(jz4740_rtc_exit);
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("RTC driver for the JZ4720/JZ4740 SoC\n");
MODULE_ALIAS("platform:jz4740-rtc");
MODULE_ALIAS("platform:jz4720-rtc");
|