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6#include <linux/kernel.h>
7#include <linux/module.h>
8#include <linux/init.h>
9#include <linux/platform_device.h>
10#include <linux/spinlock.h>
11#include <linux/rtc.h>
12#include <linux/slab.h>
13#include <linux/io.h>
14#include <linux/of.h>
15
16
17
18
19#define LPC32XX_RTC_UCOUNT 0x00
20#define LPC32XX_RTC_DCOUNT 0x04
21#define LPC32XX_RTC_MATCH0 0x08
22#define LPC32XX_RTC_MATCH1 0x0C
23#define LPC32XX_RTC_CTRL 0x10
24#define LPC32XX_RTC_INTSTAT 0x14
25#define LPC32XX_RTC_KEY 0x18
26#define LPC32XX_RTC_SRAM 0x80
27
28#define LPC32XX_RTC_CTRL_MATCH0 (1 << 0)
29#define LPC32XX_RTC_CTRL_MATCH1 (1 << 1)
30#define LPC32XX_RTC_CTRL_ONSW_MATCH0 (1 << 2)
31#define LPC32XX_RTC_CTRL_ONSW_MATCH1 (1 << 3)
32#define LPC32XX_RTC_CTRL_SW_RESET (1 << 4)
33#define LPC32XX_RTC_CTRL_CNTR_DIS (1 << 6)
34#define LPC32XX_RTC_CTRL_ONSW_FORCE_HI (1 << 7)
35
36#define LPC32XX_RTC_INTSTAT_MATCH0 (1 << 0)
37#define LPC32XX_RTC_INTSTAT_MATCH1 (1 << 1)
38#define LPC32XX_RTC_INTSTAT_ONSW (1 << 2)
39
40#define LPC32XX_RTC_KEY_ONSW_LOADVAL 0xB5C13F27
41
42#define rtc_readl(dev, reg) \
43 __raw_readl((dev)->rtc_base + (reg))
44#define rtc_writel(dev, reg, val) \
45 __raw_writel((val), (dev)->rtc_base + (reg))
46
47struct lpc32xx_rtc {
48 void __iomem *rtc_base;
49 int irq;
50 unsigned char alarm_enabled;
51 struct rtc_device *rtc;
52 spinlock_t lock;
53};
54
55static int lpc32xx_rtc_read_time(struct device *dev, struct rtc_time *time)
56{
57 unsigned long elapsed_sec;
58 struct lpc32xx_rtc *rtc = dev_get_drvdata(dev);
59
60 elapsed_sec = rtc_readl(rtc, LPC32XX_RTC_UCOUNT);
61 rtc_time64_to_tm(elapsed_sec, time);
62
63 return 0;
64}
65
66static int lpc32xx_rtc_set_time(struct device *dev, struct rtc_time *time)
67{
68 struct lpc32xx_rtc *rtc = dev_get_drvdata(dev);
69 u32 secs = rtc_tm_to_time64(time);
70 u32 tmp;
71
72 spin_lock_irq(&rtc->lock);
73
74
75 tmp = rtc_readl(rtc, LPC32XX_RTC_CTRL);
76 rtc_writel(rtc, LPC32XX_RTC_CTRL, tmp | LPC32XX_RTC_CTRL_CNTR_DIS);
77 rtc_writel(rtc, LPC32XX_RTC_UCOUNT, secs);
78 rtc_writel(rtc, LPC32XX_RTC_DCOUNT, 0xFFFFFFFF - secs);
79 rtc_writel(rtc, LPC32XX_RTC_CTRL, tmp &= ~LPC32XX_RTC_CTRL_CNTR_DIS);
80
81 spin_unlock_irq(&rtc->lock);
82
83 return 0;
84}
85
86static int lpc32xx_rtc_read_alarm(struct device *dev,
87 struct rtc_wkalrm *wkalrm)
88{
89 struct lpc32xx_rtc *rtc = dev_get_drvdata(dev);
90
91 rtc_time64_to_tm(rtc_readl(rtc, LPC32XX_RTC_MATCH0), &wkalrm->time);
92 wkalrm->enabled = rtc->alarm_enabled;
93 wkalrm->pending = !!(rtc_readl(rtc, LPC32XX_RTC_INTSTAT) &
94 LPC32XX_RTC_INTSTAT_MATCH0);
95
96 return rtc_valid_tm(&wkalrm->time);
97}
98
99static int lpc32xx_rtc_set_alarm(struct device *dev,
100 struct rtc_wkalrm *wkalrm)
101{
102 struct lpc32xx_rtc *rtc = dev_get_drvdata(dev);
103 unsigned long alarmsecs;
104 u32 tmp;
105
106 alarmsecs = rtc_tm_to_time64(&wkalrm->time);
107
108 spin_lock_irq(&rtc->lock);
109
110
111 tmp = rtc_readl(rtc, LPC32XX_RTC_CTRL);
112 rtc_writel(rtc, LPC32XX_RTC_CTRL, tmp & ~LPC32XX_RTC_CTRL_MATCH0);
113
114 rtc_writel(rtc, LPC32XX_RTC_MATCH0, alarmsecs);
115
116 rtc->alarm_enabled = wkalrm->enabled;
117 if (wkalrm->enabled) {
118 rtc_writel(rtc, LPC32XX_RTC_INTSTAT,
119 LPC32XX_RTC_INTSTAT_MATCH0);
120 rtc_writel(rtc, LPC32XX_RTC_CTRL, tmp |
121 LPC32XX_RTC_CTRL_MATCH0);
122 }
123
124 spin_unlock_irq(&rtc->lock);
125
126 return 0;
127}
128
129static int lpc32xx_rtc_alarm_irq_enable(struct device *dev,
130 unsigned int enabled)
131{
132 struct lpc32xx_rtc *rtc = dev_get_drvdata(dev);
133 u32 tmp;
134
135 spin_lock_irq(&rtc->lock);
136 tmp = rtc_readl(rtc, LPC32XX_RTC_CTRL);
137
138 if (enabled) {
139 rtc->alarm_enabled = 1;
140 tmp |= LPC32XX_RTC_CTRL_MATCH0;
141 } else {
142 rtc->alarm_enabled = 0;
143 tmp &= ~LPC32XX_RTC_CTRL_MATCH0;
144 }
145
146 rtc_writel(rtc, LPC32XX_RTC_CTRL, tmp);
147 spin_unlock_irq(&rtc->lock);
148
149 return 0;
150}
151
152static irqreturn_t lpc32xx_rtc_alarm_interrupt(int irq, void *dev)
153{
154 struct lpc32xx_rtc *rtc = dev;
155
156 spin_lock(&rtc->lock);
157
158
159 rtc_writel(rtc, LPC32XX_RTC_CTRL,
160 rtc_readl(rtc, LPC32XX_RTC_CTRL) &
161 ~LPC32XX_RTC_CTRL_MATCH0);
162 rtc->alarm_enabled = 0;
163
164
165
166
167
168 rtc_writel(rtc, LPC32XX_RTC_MATCH0, 0xFFFFFFFF);
169 rtc_writel(rtc, LPC32XX_RTC_INTSTAT, LPC32XX_RTC_INTSTAT_MATCH0);
170
171 spin_unlock(&rtc->lock);
172
173 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
174
175 return IRQ_HANDLED;
176}
177
178static const struct rtc_class_ops lpc32xx_rtc_ops = {
179 .read_time = lpc32xx_rtc_read_time,
180 .set_time = lpc32xx_rtc_set_time,
181 .read_alarm = lpc32xx_rtc_read_alarm,
182 .set_alarm = lpc32xx_rtc_set_alarm,
183 .alarm_irq_enable = lpc32xx_rtc_alarm_irq_enable,
184};
185
186static int lpc32xx_rtc_probe(struct platform_device *pdev)
187{
188 struct resource *res;
189 struct lpc32xx_rtc *rtc;
190 int err;
191 u32 tmp;
192
193 rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
194 if (unlikely(!rtc))
195 return -ENOMEM;
196
197 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
198 rtc->rtc_base = devm_ioremap_resource(&pdev->dev, res);
199 if (IS_ERR(rtc->rtc_base))
200 return PTR_ERR(rtc->rtc_base);
201
202 spin_lock_init(&rtc->lock);
203
204
205
206
207
208
209 tmp = rtc_readl(rtc, LPC32XX_RTC_CTRL);
210 if (rtc_readl(rtc, LPC32XX_RTC_KEY) != LPC32XX_RTC_KEY_ONSW_LOADVAL) {
211 tmp &= ~(LPC32XX_RTC_CTRL_SW_RESET |
212 LPC32XX_RTC_CTRL_CNTR_DIS |
213 LPC32XX_RTC_CTRL_MATCH0 |
214 LPC32XX_RTC_CTRL_MATCH1 |
215 LPC32XX_RTC_CTRL_ONSW_MATCH0 |
216 LPC32XX_RTC_CTRL_ONSW_MATCH1 |
217 LPC32XX_RTC_CTRL_ONSW_FORCE_HI);
218 rtc_writel(rtc, LPC32XX_RTC_CTRL, tmp);
219
220
221 rtc_writel(rtc, LPC32XX_RTC_MATCH0, 0xFFFFFFFF);
222 rtc_writel(rtc, LPC32XX_RTC_INTSTAT,
223 LPC32XX_RTC_INTSTAT_MATCH0 |
224 LPC32XX_RTC_INTSTAT_MATCH1 |
225 LPC32XX_RTC_INTSTAT_ONSW);
226
227
228 rtc_writel(rtc, LPC32XX_RTC_KEY,
229 LPC32XX_RTC_KEY_ONSW_LOADVAL);
230 } else {
231 rtc_writel(rtc, LPC32XX_RTC_CTRL,
232 tmp & ~LPC32XX_RTC_CTRL_MATCH0);
233 }
234
235 platform_set_drvdata(pdev, rtc);
236
237 rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
238 if (IS_ERR(rtc->rtc))
239 return PTR_ERR(rtc->rtc);
240
241 rtc->rtc->ops = &lpc32xx_rtc_ops;
242 rtc->rtc->range_max = U32_MAX;
243
244 err = rtc_register_device(rtc->rtc);
245 if (err)
246 return err;
247
248
249
250
251
252 rtc->irq = platform_get_irq(pdev, 0);
253 if (rtc->irq < 0) {
254 dev_warn(&pdev->dev, "Can't get interrupt resource\n");
255 } else {
256 if (devm_request_irq(&pdev->dev, rtc->irq,
257 lpc32xx_rtc_alarm_interrupt,
258 0, pdev->name, rtc) < 0) {
259 dev_warn(&pdev->dev, "Can't request interrupt.\n");
260 rtc->irq = -1;
261 } else {
262 device_init_wakeup(&pdev->dev, 1);
263 }
264 }
265
266 return 0;
267}
268
269static int lpc32xx_rtc_remove(struct platform_device *pdev)
270{
271 struct lpc32xx_rtc *rtc = platform_get_drvdata(pdev);
272
273 if (rtc->irq >= 0)
274 device_init_wakeup(&pdev->dev, 0);
275
276 return 0;
277}
278
279#ifdef CONFIG_PM
280static int lpc32xx_rtc_suspend(struct device *dev)
281{
282 struct lpc32xx_rtc *rtc = dev_get_drvdata(dev);
283
284 if (rtc->irq >= 0) {
285 if (device_may_wakeup(dev))
286 enable_irq_wake(rtc->irq);
287 else
288 disable_irq_wake(rtc->irq);
289 }
290
291 return 0;
292}
293
294static int lpc32xx_rtc_resume(struct device *dev)
295{
296 struct lpc32xx_rtc *rtc = dev_get_drvdata(dev);
297
298 if (rtc->irq >= 0 && device_may_wakeup(dev))
299 disable_irq_wake(rtc->irq);
300
301 return 0;
302}
303
304
305static int lpc32xx_rtc_freeze(struct device *dev)
306{
307 struct lpc32xx_rtc *rtc = dev_get_drvdata(dev);
308
309 spin_lock_irq(&rtc->lock);
310
311 rtc_writel(rtc, LPC32XX_RTC_CTRL,
312 rtc_readl(rtc, LPC32XX_RTC_CTRL) &
313 ~LPC32XX_RTC_CTRL_MATCH0);
314
315 spin_unlock_irq(&rtc->lock);
316
317 return 0;
318}
319
320static int lpc32xx_rtc_thaw(struct device *dev)
321{
322 struct lpc32xx_rtc *rtc = dev_get_drvdata(dev);
323
324 if (rtc->alarm_enabled) {
325 spin_lock_irq(&rtc->lock);
326
327 rtc_writel(rtc, LPC32XX_RTC_CTRL,
328 rtc_readl(rtc, LPC32XX_RTC_CTRL) |
329 LPC32XX_RTC_CTRL_MATCH0);
330
331 spin_unlock_irq(&rtc->lock);
332 }
333
334 return 0;
335}
336
337static const struct dev_pm_ops lpc32xx_rtc_pm_ops = {
338 .suspend = lpc32xx_rtc_suspend,
339 .resume = lpc32xx_rtc_resume,
340 .freeze = lpc32xx_rtc_freeze,
341 .thaw = lpc32xx_rtc_thaw,
342 .restore = lpc32xx_rtc_resume
343};
344
345#define LPC32XX_RTC_PM_OPS (&lpc32xx_rtc_pm_ops)
346#else
347#define LPC32XX_RTC_PM_OPS NULL
348#endif
349
350#ifdef CONFIG_OF
351static const struct of_device_id lpc32xx_rtc_match[] = {
352 { .compatible = "nxp,lpc3220-rtc" },
353 { }
354};
355MODULE_DEVICE_TABLE(of, lpc32xx_rtc_match);
356#endif
357
358static struct platform_driver lpc32xx_rtc_driver = {
359 .probe = lpc32xx_rtc_probe,
360 .remove = lpc32xx_rtc_remove,
361 .driver = {
362 .name = "rtc-lpc32xx",
363 .pm = LPC32XX_RTC_PM_OPS,
364 .of_match_table = of_match_ptr(lpc32xx_rtc_match),
365 },
366};
367
368module_platform_driver(lpc32xx_rtc_driver);
369
370MODULE_AUTHOR("Kevin Wells <wellsk40@gmail.com");
371MODULE_DESCRIPTION("RTC driver for the LPC32xx SoC");
372MODULE_LICENSE("GPL");
373MODULE_ALIAS("platform:rtc-lpc32xx");
374
