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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 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
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
111
112
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)
165 ret = jz4740_rtc_ctrl_set_bits(rtc,
166 JZ_RTC_CTRL_AE | JZ_RTC_CTRL_AF_IRQ, alrm->enabled);
167
168 return ret;
169}
170
171static int jz4740_rtc_alarm_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_AF_IRQ, enable);
175}
176
177static struct rtc_class_ops jz4740_rtc_ops = {
178 .read_time = jz4740_rtc_read_time,
179 .set_mmss = jz4740_rtc_set_mmss,
180 .read_alarm = jz4740_rtc_read_alarm,
181 .set_alarm = jz4740_rtc_set_alarm,
182 .alarm_irq_enable = jz4740_rtc_alarm_irq_enable,
183};
184
185static irqreturn_t jz4740_rtc_irq(int irq, void *data)
186{
187 struct jz4740_rtc *rtc = data;
188 uint32_t ctrl;
189 unsigned long events = 0;
190
191 ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
192
193 if (ctrl & JZ_RTC_CTRL_1HZ)
194 events |= (RTC_UF | RTC_IRQF);
195
196 if (ctrl & JZ_RTC_CTRL_AF)
197 events |= (RTC_AF | RTC_IRQF);
198
199 rtc_update_irq(rtc->rtc, 1, events);
200
201 jz4740_rtc_ctrl_set_bits(rtc, JZ_RTC_CTRL_1HZ | JZ_RTC_CTRL_AF, false);
202
203 return IRQ_HANDLED;
204}
205
206void jz4740_rtc_poweroff(struct device *dev)
207{
208 struct jz4740_rtc *rtc = dev_get_drvdata(dev);
209 jz4740_rtc_reg_write(rtc, JZ_REG_RTC_HIBERNATE, 1);
210}
211EXPORT_SYMBOL_GPL(jz4740_rtc_poweroff);
212
213static int jz4740_rtc_probe(struct platform_device *pdev)
214{
215 int ret;
216 struct jz4740_rtc *rtc;
217 uint32_t scratchpad;
218
219 rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);
220 if (!rtc)
221 return -ENOMEM;
222
223 rtc->irq = platform_get_irq(pdev, 0);
224 if (rtc->irq < 0) {
225 ret = -ENOENT;
226 dev_err(&pdev->dev, "Failed to get platform irq\n");
227 goto err_free;
228 }
229
230 rtc->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
231 if (!rtc->mem) {
232 ret = -ENOENT;
233 dev_err(&pdev->dev, "Failed to get platform mmio memory\n");
234 goto err_free;
235 }
236
237 rtc->mem = request_mem_region(rtc->mem->start, resource_size(rtc->mem),
238 pdev->name);
239 if (!rtc->mem) {
240 ret = -EBUSY;
241 dev_err(&pdev->dev, "Failed to request mmio memory region\n");
242 goto err_free;
243 }
244
245 rtc->base = ioremap_nocache(rtc->mem->start, resource_size(rtc->mem));
246 if (!rtc->base) {
247 ret = -EBUSY;
248 dev_err(&pdev->dev, "Failed to ioremap mmio memory\n");
249 goto err_release_mem_region;
250 }
251
252 spin_lock_init(&rtc->lock);
253
254 platform_set_drvdata(pdev, rtc);
255
256 device_init_wakeup(&pdev->dev, 1);
257
258 rtc->rtc = rtc_device_register(pdev->name, &pdev->dev, &jz4740_rtc_ops,
259 THIS_MODULE);
260 if (IS_ERR(rtc->rtc)) {
261 ret = PTR_ERR(rtc->rtc);
262 dev_err(&pdev->dev, "Failed to register rtc device: %d\n", ret);
263 goto err_iounmap;
264 }
265
266 ret = request_irq(rtc->irq, jz4740_rtc_irq, 0,
267 pdev->name, rtc);
268 if (ret) {
269 dev_err(&pdev->dev, "Failed to request rtc irq: %d\n", ret);
270 goto err_unregister_rtc;
271 }
272
273 scratchpad = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SCRATCHPAD);
274 if (scratchpad != 0x12345678) {
275 ret = jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SCRATCHPAD, 0x12345678);
276 ret = jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SEC, 0);
277 if (ret) {
278 dev_err(&pdev->dev, "Could not write write to RTC registers\n");
279 goto err_free_irq;
280 }
281 }
282
283 return 0;
284
285err_free_irq:
286 free_irq(rtc->irq, rtc);
287err_unregister_rtc:
288 rtc_device_unregister(rtc->rtc);
289err_iounmap:
290 platform_set_drvdata(pdev, NULL);
291 iounmap(rtc->base);
292err_release_mem_region:
293 release_mem_region(rtc->mem->start, resource_size(rtc->mem));
294err_free:
295 kfree(rtc);
296
297 return ret;
298}
299
300static int jz4740_rtc_remove(struct platform_device *pdev)
301{
302 struct jz4740_rtc *rtc = platform_get_drvdata(pdev);
303
304 free_irq(rtc->irq, rtc);
305
306 rtc_device_unregister(rtc->rtc);
307
308 iounmap(rtc->base);
309 release_mem_region(rtc->mem->start, resource_size(rtc->mem));
310
311 kfree(rtc);
312
313 platform_set_drvdata(pdev, NULL);
314
315 return 0;
316}
317
318
319#ifdef CONFIG_PM
320static int jz4740_rtc_suspend(struct device *dev)
321{
322 struct jz4740_rtc *rtc = dev_get_drvdata(dev);
323
324 if (device_may_wakeup(dev))
325 enable_irq_wake(rtc->irq);
326 return 0;
327}
328
329static int jz4740_rtc_resume(struct device *dev)
330{
331 struct jz4740_rtc *rtc = dev_get_drvdata(dev);
332
333 if (device_may_wakeup(dev))
334 disable_irq_wake(rtc->irq);
335 return 0;
336}
337
338static const struct dev_pm_ops jz4740_pm_ops = {
339 .suspend = jz4740_rtc_suspend,
340 .resume = jz4740_rtc_resume,
341};
342#define JZ4740_RTC_PM_OPS (&jz4740_pm_ops)
343
344#else
345#define JZ4740_RTC_PM_OPS NULL
346#endif
347
348static struct platform_driver jz4740_rtc_driver = {
349 .probe = jz4740_rtc_probe,
350 .remove = jz4740_rtc_remove,
351 .driver = {
352 .name = "jz4740-rtc",
353 .owner = THIS_MODULE,
354 .pm = JZ4740_RTC_PM_OPS,
355 },
356};
357
358module_platform_driver(jz4740_rtc_driver);
359
360MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
361MODULE_LICENSE("GPL");
362MODULE_DESCRIPTION("RTC driver for the JZ4740 SoC\n");
363MODULE_ALIAS("platform:jz4740-rtc");
364
