This source file includes following definitions.
- cdns_rtc_set_enabled
- cdns_rtc_get_enabled
- cdns_rtc_irq_handler
- cdns_rtc_time2reg
- cdns_rtc_reg2time
- cdns_rtc_read_time
- cdns_rtc_set_time
- cdns_rtc_alarm_irq_enable
- cdns_rtc_read_alarm
- cdns_rtc_set_alarm
- cdns_rtc_probe
- cdns_rtc_remove
- cdns_rtc_suspend
- cdns_rtc_resume
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10 #include <linux/module.h>
11 #include <linux/platform_device.h>
12 #include <linux/of.h>
13 #include <linux/io.h>
14 #include <linux/rtc.h>
15 #include <linux/clk.h>
16 #include <linux/bcd.h>
17 #include <linux/bitfield.h>
18 #include <linux/interrupt.h>
19 #include <linux/pm_wakeirq.h>
20
21
22 #define CDNS_RTC_CTLR 0x00
23 #define CDNS_RTC_HMR 0x04
24 #define CDNS_RTC_TIMR 0x08
25 #define CDNS_RTC_CALR 0x0C
26 #define CDNS_RTC_TIMAR 0x10
27 #define CDNS_RTC_CALAR 0x14
28 #define CDNS_RTC_AENR 0x18
29 #define CDNS_RTC_EFLR 0x1C
30 #define CDNS_RTC_IENR 0x20
31 #define CDNS_RTC_IDISR 0x24
32 #define CDNS_RTC_IMSKR 0x28
33 #define CDNS_RTC_STSR 0x2C
34 #define CDNS_RTC_KRTCR 0x30
35
36
37 #define CDNS_RTC_CTLR_TIME BIT(0)
38 #define CDNS_RTC_CTLR_CAL BIT(1)
39 #define CDNS_RTC_CTLR_TIME_CAL (CDNS_RTC_CTLR_TIME | CDNS_RTC_CTLR_CAL)
40
41
42 #define CDNS_RTC_STSR_VT BIT(0)
43 #define CDNS_RTC_STSR_VC BIT(1)
44 #define CDNS_RTC_STSR_VTA BIT(2)
45 #define CDNS_RTC_STSR_VCA BIT(3)
46 #define CDNS_RTC_STSR_VT_VC (CDNS_RTC_STSR_VT | CDNS_RTC_STSR_VC)
47 #define CDNS_RTC_STSR_VTA_VCA (CDNS_RTC_STSR_VTA | CDNS_RTC_STSR_VCA)
48
49
50 #define CDNS_RTC_KRTCR_KRTC BIT(0)
51
52
53 #define CDNS_RTC_AEI_HOS BIT(0)
54 #define CDNS_RTC_AEI_SEC BIT(1)
55 #define CDNS_RTC_AEI_MIN BIT(2)
56 #define CDNS_RTC_AEI_HOUR BIT(3)
57 #define CDNS_RTC_AEI_DATE BIT(4)
58 #define CDNS_RTC_AEI_MNTH BIT(5)
59 #define CDNS_RTC_AEI_ALRM BIT(6)
60
61
62 #define CDNS_RTC_TIME_H GENMASK(7, 0)
63 #define CDNS_RTC_TIME_S GENMASK(14, 8)
64 #define CDNS_RTC_TIME_M GENMASK(22, 16)
65 #define CDNS_RTC_TIME_HR GENMASK(29, 24)
66 #define CDNS_RTC_TIME_PM BIT(30)
67 #define CDNS_RTC_TIME_CH BIT(31)
68
69
70 #define CDNS_RTC_CAL_DAY GENMASK(2, 0)
71 #define CDNS_RTC_CAL_M GENMASK(7, 3)
72 #define CDNS_RTC_CAL_D GENMASK(13, 8)
73 #define CDNS_RTC_CAL_Y GENMASK(23, 16)
74 #define CDNS_RTC_CAL_C GENMASK(29, 24)
75 #define CDNS_RTC_CAL_CH BIT(31)
76
77 #define CDNS_RTC_MAX_REGS_TRIES 3
78
79 struct cdns_rtc {
80 struct rtc_device *rtc_dev;
81 struct clk *pclk;
82 struct clk *ref_clk;
83 void __iomem *regs;
84 int irq;
85 };
86
87 static void cdns_rtc_set_enabled(struct cdns_rtc *crtc, bool enabled)
88 {
89 u32 reg = enabled ? 0x0 : CDNS_RTC_CTLR_TIME_CAL;
90
91 writel(reg, crtc->regs + CDNS_RTC_CTLR);
92 }
93
94 static bool cdns_rtc_get_enabled(struct cdns_rtc *crtc)
95 {
96 return !(readl(crtc->regs + CDNS_RTC_CTLR) & CDNS_RTC_CTLR_TIME_CAL);
97 }
98
99 static irqreturn_t cdns_rtc_irq_handler(int irq, void *id)
100 {
101 struct device *dev = id;
102 struct cdns_rtc *crtc = dev_get_drvdata(dev);
103
104
105 if (!(readl(crtc->regs + CDNS_RTC_EFLR) & CDNS_RTC_AEI_ALRM))
106 return IRQ_NONE;
107
108 rtc_update_irq(crtc->rtc_dev, 1, RTC_IRQF | RTC_AF);
109 return IRQ_HANDLED;
110 }
111
112 static u32 cdns_rtc_time2reg(struct rtc_time *tm)
113 {
114 return FIELD_PREP(CDNS_RTC_TIME_S, bin2bcd(tm->tm_sec))
115 | FIELD_PREP(CDNS_RTC_TIME_M, bin2bcd(tm->tm_min))
116 | FIELD_PREP(CDNS_RTC_TIME_HR, bin2bcd(tm->tm_hour));
117 }
118
119 static void cdns_rtc_reg2time(u32 reg, struct rtc_time *tm)
120 {
121 tm->tm_sec = bcd2bin(FIELD_GET(CDNS_RTC_TIME_S, reg));
122 tm->tm_min = bcd2bin(FIELD_GET(CDNS_RTC_TIME_M, reg));
123 tm->tm_hour = bcd2bin(FIELD_GET(CDNS_RTC_TIME_HR, reg));
124 }
125
126 static int cdns_rtc_read_time(struct device *dev, struct rtc_time *tm)
127 {
128 struct cdns_rtc *crtc = dev_get_drvdata(dev);
129 u32 reg;
130
131
132 if (!cdns_rtc_get_enabled(crtc))
133 return -EINVAL;
134
135 cdns_rtc_set_enabled(crtc, false);
136
137 reg = readl(crtc->regs + CDNS_RTC_TIMR);
138 cdns_rtc_reg2time(reg, tm);
139
140 reg = readl(crtc->regs + CDNS_RTC_CALR);
141 tm->tm_mday = bcd2bin(FIELD_GET(CDNS_RTC_CAL_D, reg));
142 tm->tm_mon = bcd2bin(FIELD_GET(CDNS_RTC_CAL_M, reg)) - 1;
143 tm->tm_year = bcd2bin(FIELD_GET(CDNS_RTC_CAL_Y, reg))
144 + bcd2bin(FIELD_GET(CDNS_RTC_CAL_C, reg)) * 100 - 1900;
145 tm->tm_wday = bcd2bin(FIELD_GET(CDNS_RTC_CAL_DAY, reg)) - 1;
146
147 cdns_rtc_set_enabled(crtc, true);
148 return 0;
149 }
150
151 static int cdns_rtc_set_time(struct device *dev, struct rtc_time *tm)
152 {
153 struct cdns_rtc *crtc = dev_get_drvdata(dev);
154 u32 timr, calr, stsr;
155 int ret = -EIO;
156 int year = tm->tm_year + 1900;
157 int tries;
158
159 cdns_rtc_set_enabled(crtc, false);
160
161 timr = cdns_rtc_time2reg(tm);
162
163 calr = FIELD_PREP(CDNS_RTC_CAL_D, bin2bcd(tm->tm_mday))
164 | FIELD_PREP(CDNS_RTC_CAL_M, bin2bcd(tm->tm_mon + 1))
165 | FIELD_PREP(CDNS_RTC_CAL_Y, bin2bcd(year % 100))
166 | FIELD_PREP(CDNS_RTC_CAL_C, bin2bcd(year / 100))
167 | FIELD_PREP(CDNS_RTC_CAL_DAY, tm->tm_wday + 1);
168
169
170 for (tries = 0; tries < CDNS_RTC_MAX_REGS_TRIES; tries++) {
171 writel(timr, crtc->regs + CDNS_RTC_TIMR);
172 writel(calr, crtc->regs + CDNS_RTC_CALR);
173 stsr = readl(crtc->regs + CDNS_RTC_STSR);
174
175 if ((stsr & CDNS_RTC_STSR_VT_VC) == CDNS_RTC_STSR_VT_VC) {
176 ret = 0;
177 break;
178 }
179 }
180
181 cdns_rtc_set_enabled(crtc, true);
182 return ret;
183 }
184
185 static int cdns_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
186 {
187 struct cdns_rtc *crtc = dev_get_drvdata(dev);
188
189 if (enabled) {
190 writel((CDNS_RTC_AEI_SEC | CDNS_RTC_AEI_MIN | CDNS_RTC_AEI_HOUR
191 | CDNS_RTC_AEI_DATE | CDNS_RTC_AEI_MNTH),
192 crtc->regs + CDNS_RTC_AENR);
193 writel(CDNS_RTC_AEI_ALRM, crtc->regs + CDNS_RTC_IENR);
194 } else {
195 writel(0, crtc->regs + CDNS_RTC_AENR);
196 writel(CDNS_RTC_AEI_ALRM, crtc->regs + CDNS_RTC_IDISR);
197 }
198
199 return 0;
200 }
201
202 static int cdns_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
203 {
204 struct cdns_rtc *crtc = dev_get_drvdata(dev);
205 u32 reg;
206
207 reg = readl(crtc->regs + CDNS_RTC_TIMAR);
208 cdns_rtc_reg2time(reg, &alarm->time);
209
210 reg = readl(crtc->regs + CDNS_RTC_CALAR);
211 alarm->time.tm_mday = bcd2bin(FIELD_GET(CDNS_RTC_CAL_D, reg));
212 alarm->time.tm_mon = bcd2bin(FIELD_GET(CDNS_RTC_CAL_M, reg)) - 1;
213
214 return 0;
215 }
216
217 static int cdns_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
218 {
219 struct cdns_rtc *crtc = dev_get_drvdata(dev);
220 int ret = -EIO;
221 int tries;
222 u32 timar, calar, stsr;
223
224 cdns_rtc_alarm_irq_enable(dev, 0);
225
226 timar = cdns_rtc_time2reg(&alarm->time);
227 calar = FIELD_PREP(CDNS_RTC_CAL_D, bin2bcd(alarm->time.tm_mday))
228 | FIELD_PREP(CDNS_RTC_CAL_M, bin2bcd(alarm->time.tm_mon + 1));
229
230
231 for (tries = 0; tries < CDNS_RTC_MAX_REGS_TRIES; tries++) {
232 writel(timar, crtc->regs + CDNS_RTC_TIMAR);
233 writel(calar, crtc->regs + CDNS_RTC_CALAR);
234 stsr = readl(crtc->regs + CDNS_RTC_STSR);
235
236 if ((stsr & CDNS_RTC_STSR_VTA_VCA) == CDNS_RTC_STSR_VTA_VCA) {
237 ret = 0;
238 break;
239 }
240 }
241
242 if (!ret)
243 cdns_rtc_alarm_irq_enable(dev, alarm->enabled);
244 return ret;
245 }
246
247 static const struct rtc_class_ops cdns_rtc_ops = {
248 .read_time = cdns_rtc_read_time,
249 .set_time = cdns_rtc_set_time,
250 .read_alarm = cdns_rtc_read_alarm,
251 .set_alarm = cdns_rtc_set_alarm,
252 .alarm_irq_enable = cdns_rtc_alarm_irq_enable,
253 };
254
255 static int cdns_rtc_probe(struct platform_device *pdev)
256 {
257 struct cdns_rtc *crtc;
258 struct resource *res;
259 int ret;
260 unsigned long ref_clk_freq;
261
262 crtc = devm_kzalloc(&pdev->dev, sizeof(*crtc), GFP_KERNEL);
263 if (!crtc)
264 return -ENOMEM;
265
266 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
267 crtc->regs = devm_ioremap_resource(&pdev->dev, res);
268 if (IS_ERR(crtc->regs))
269 return PTR_ERR(crtc->regs);
270
271 crtc->irq = platform_get_irq(pdev, 0);
272 if (crtc->irq < 0)
273 return -EINVAL;
274
275 crtc->pclk = devm_clk_get(&pdev->dev, "pclk");
276 if (IS_ERR(crtc->pclk)) {
277 ret = PTR_ERR(crtc->pclk);
278 dev_err(&pdev->dev,
279 "Failed to retrieve the peripheral clock, %d\n", ret);
280 return ret;
281 }
282
283 crtc->ref_clk = devm_clk_get(&pdev->dev, "ref_clk");
284 if (IS_ERR(crtc->ref_clk)) {
285 ret = PTR_ERR(crtc->ref_clk);
286 dev_err(&pdev->dev,
287 "Failed to retrieve the reference clock, %d\n", ret);
288 return ret;
289 }
290
291 crtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
292 if (IS_ERR(crtc->rtc_dev))
293 return PTR_ERR(crtc->rtc_dev);
294
295 platform_set_drvdata(pdev, crtc);
296
297 ret = clk_prepare_enable(crtc->pclk);
298 if (ret) {
299 dev_err(&pdev->dev,
300 "Failed to enable the peripheral clock, %d\n", ret);
301 return ret;
302 }
303
304 ret = clk_prepare_enable(crtc->ref_clk);
305 if (ret) {
306 dev_err(&pdev->dev,
307 "Failed to enable the reference clock, %d\n", ret);
308 goto err_disable_pclk;
309 }
310
311 ref_clk_freq = clk_get_rate(crtc->ref_clk);
312 if ((ref_clk_freq != 1) && (ref_clk_freq != 100)) {
313 dev_err(&pdev->dev,
314 "Invalid reference clock frequency %lu Hz.\n",
315 ref_clk_freq);
316 ret = -EINVAL;
317 goto err_disable_ref_clk;
318 }
319
320 ret = devm_request_irq(&pdev->dev, crtc->irq,
321 cdns_rtc_irq_handler, 0,
322 dev_name(&pdev->dev), &pdev->dev);
323 if (ret) {
324 dev_err(&pdev->dev,
325 "Failed to request interrupt for the device, %d\n",
326 ret);
327 goto err_disable_ref_clk;
328 }
329
330
331 crtc->rtc_dev->range_min = mktime64(1900, 1, 1, 0, 0, 0);
332 crtc->rtc_dev->range_max = mktime64(2999, 12, 31, 23, 59, 59);
333
334 crtc->rtc_dev->ops = &cdns_rtc_ops;
335 device_init_wakeup(&pdev->dev, true);
336
337
338 writel(0, crtc->regs + CDNS_RTC_HMR);
339 writel(CDNS_RTC_KRTCR_KRTC, crtc->regs + CDNS_RTC_KRTCR);
340
341 ret = rtc_register_device(crtc->rtc_dev);
342 if (ret)
343 goto err_disable_wakeup;
344
345 return 0;
346
347 err_disable_wakeup:
348 device_init_wakeup(&pdev->dev, false);
349
350 err_disable_ref_clk:
351 clk_disable_unprepare(crtc->ref_clk);
352
353 err_disable_pclk:
354 clk_disable_unprepare(crtc->pclk);
355
356 return ret;
357 }
358
359 static int cdns_rtc_remove(struct platform_device *pdev)
360 {
361 struct cdns_rtc *crtc = platform_get_drvdata(pdev);
362
363 cdns_rtc_alarm_irq_enable(&pdev->dev, 0);
364 device_init_wakeup(&pdev->dev, 0);
365
366 clk_disable_unprepare(crtc->pclk);
367 clk_disable_unprepare(crtc->ref_clk);
368
369 return 0;
370 }
371
372 #ifdef CONFIG_PM_SLEEP
373 static int cdns_rtc_suspend(struct device *dev)
374 {
375 struct cdns_rtc *crtc = dev_get_drvdata(dev);
376
377 if (device_may_wakeup(dev))
378 enable_irq_wake(crtc->irq);
379
380 return 0;
381 }
382
383 static int cdns_rtc_resume(struct device *dev)
384 {
385 struct cdns_rtc *crtc = dev_get_drvdata(dev);
386
387 if (device_may_wakeup(dev))
388 disable_irq_wake(crtc->irq);
389
390 return 0;
391 }
392 #endif
393
394 static SIMPLE_DEV_PM_OPS(cdns_rtc_pm_ops, cdns_rtc_suspend, cdns_rtc_resume);
395
396 static const struct of_device_id cdns_rtc_of_match[] = {
397 { .compatible = "cdns,rtc-r109v3" },
398 { },
399 };
400 MODULE_DEVICE_TABLE(of, cdns_rtc_of_match);
401
402 static struct platform_driver cdns_rtc_driver = {
403 .driver = {
404 .name = "cdns-rtc",
405 .of_match_table = cdns_rtc_of_match,
406 .pm = &cdns_rtc_pm_ops,
407 },
408 .probe = cdns_rtc_probe,
409 .remove = cdns_rtc_remove,
410 };
411 module_platform_driver(cdns_rtc_driver);
412
413 MODULE_AUTHOR("Jan Kotas <jank@cadence.com>");
414 MODULE_DESCRIPTION("Cadence RTC driver");
415 MODULE_LICENSE("GPL v2");
416 MODULE_ALIAS("platform:cdns-rtc");