?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / drivers / rtc / rtc-rk808.c
blobc0334c602e88efe022a3e78976ceb91c034536f0
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * RTC driver for Rockchip RK808
4 *
5 * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
6 *
7 * Author: Chris Zhong <zyw@rock-chips.com>
8 * Author: Zhang Qing <zhangqing@rock-chips.com>
9 */
10
11 #include <linux/module.h>
12 #include <linux/kernel.h>
13 #include <linux/rtc.h>
14 #include <linux/bcd.h>
15 #include <linux/mfd/rk808.h>
16 #include <linux/platform_device.h>
17 #include <linux/i2c.h>
18
19 /* RTC_CTRL_REG bitfields */
20 #define BIT_RTC_CTRL_REG_STOP_RTC_M BIT(0)
21
22 /* RK808 has a shadowed register for saving a "frozen" RTC time.
23 * When user setting "GET_TIME" to 1, the time will save in this shadowed
24 * register. If set "READSEL" to 1, user read rtc time register, actually
25 * get the time of that moment. If we need the real time, clr this bit.
26 */
27 #define BIT_RTC_CTRL_REG_RTC_GET_TIME BIT(6)
28 #define BIT_RTC_CTRL_REG_RTC_READSEL_M BIT(7)
29 #define BIT_RTC_INTERRUPTS_REG_IT_ALARM_M BIT(3)
30 #define RTC_STATUS_MASK 0xFE
31
32 #define SECONDS_REG_MSK 0x7F
33 #define MINUTES_REG_MAK 0x7F
34 #define HOURS_REG_MSK 0x3F
35 #define DAYS_REG_MSK 0x3F
36 #define MONTHS_REG_MSK 0x1F
37 #define YEARS_REG_MSK 0xFF
38 #define WEEKS_REG_MSK 0x7
39
40 /* REG_SECONDS_REG through REG_YEARS_REG is how many registers? */
41
42 #define NUM_TIME_REGS (RK808_WEEKS_REG - RK808_SECONDS_REG + 1)
43 #define NUM_ALARM_REGS (RK808_ALARM_YEARS_REG - RK808_ALARM_SECONDS_REG + 1)
44
45 struct rk_rtc_compat_reg {
46 unsigned int ctrl_reg;
47 unsigned int status_reg;
48 unsigned int alarm_seconds_reg;
49 unsigned int int_reg;
50 unsigned int seconds_reg;
51 };
52
53 struct rk808_rtc {
54 struct rk808 *rk808;
55 struct rtc_device *rtc;
56 struct rk_rtc_compat_reg *creg;
57 int irq;
58 };
59
60 /*
61 * The Rockchip calendar used by the RK808 counts November with 31 days. We use
62 * these translation functions to convert its dates to/from the Gregorian
63 * calendar used by the rest of the world. We arbitrarily define Jan 1st, 2016
64 * as the day when both calendars were in sync, and treat all other dates
65 * relative to that.
66 * NOTE: Other system software (e.g. firmware) that reads the same hardware must
67 * implement this exact same conversion algorithm, with the same anchor date.
68 */
69 static time64_t nov2dec_transitions(struct rtc_time *tm)
70 {
71 return (tm->tm_year + 1900) - 2016 + (tm->tm_mon + 1 > 11 ? 1 : 0);
72 }
73
74 static void rockchip_to_gregorian(struct rtc_time *tm)
75 {
76 /* If it's Nov 31st, rtc_tm_to_time64() will count that like Dec 1st */
77 time64_t time = rtc_tm_to_time64(tm);
78 rtc_time64_to_tm(time + nov2dec_transitions(tm) * 86400, tm);
79 }
80
81 static void gregorian_to_rockchip(struct rtc_time *tm)
82 {
83 time64_t extra_days = nov2dec_transitions(tm);
84 time64_t time = rtc_tm_to_time64(tm);
85 rtc_time64_to_tm(time - extra_days * 86400, tm);
86
87 /* Compensate if we went back over Nov 31st (will work up to 2381) */
88 if (nov2dec_transitions(tm) < extra_days) {
89 if (tm->tm_mon + 1 == 11)
90 tm->tm_mday++; /* This may result in 31! */
91 else
92 rtc_time64_to_tm(time - (extra_days - 1) * 86400, tm);
93 }
94 }
95
96 /* Read current time and date in RTC */
97 static int rk808_rtc_readtime(struct device *dev, struct rtc_time *tm)
98 {
99 struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
100 struct rk808 *rk808 = rk808_rtc->rk808;
101 u8 rtc_data[NUM_TIME_REGS];
102 int ret;
103
104 /* Force an update of the shadowed registers right now */
105 ret = regmap_update_bits(rk808->regmap, rk808_rtc->creg->ctrl_reg,
106 BIT_RTC_CTRL_REG_RTC_GET_TIME,
107 BIT_RTC_CTRL_REG_RTC_GET_TIME);
108 if (ret) {
109 dev_err(dev, "Failed to update bits rtc_ctrl: %d\n", ret);
110 return ret;
111 }
112
113 /*
114 * After we set the GET_TIME bit, the rtc time can't be read
115 * immediately. So we should wait up to 31.25 us, about one cycle of
116 * 32khz. If we clear the GET_TIME bit here, the time of i2c transfer
117 * certainly more than 31.25us: 16 * 2.5us at 400kHz bus frequency.
118 */
119 ret = regmap_update_bits(rk808->regmap, rk808_rtc->creg->ctrl_reg,
120 BIT_RTC_CTRL_REG_RTC_GET_TIME,
121 0);
122 if (ret) {
123 dev_err(dev, "Failed to update bits rtc_ctrl: %d\n", ret);
124 return ret;
125 }
126
127 ret = regmap_bulk_read(rk808->regmap, rk808_rtc->creg->seconds_reg,
128 rtc_data, NUM_TIME_REGS);
129 if (ret) {
130 dev_err(dev, "Failed to bulk read rtc_data: %d\n", ret);
131 return ret;
132 }
133
134 tm->tm_sec = bcd2bin(rtc_data[0] & SECONDS_REG_MSK);
135 tm->tm_min = bcd2bin(rtc_data[1] & MINUTES_REG_MAK);
136 tm->tm_hour = bcd2bin(rtc_data[2] & HOURS_REG_MSK);
137 tm->tm_mday = bcd2bin(rtc_data[3] & DAYS_REG_MSK);
138 tm->tm_mon = (bcd2bin(rtc_data[4] & MONTHS_REG_MSK)) - 1;
139 tm->tm_year = (bcd2bin(rtc_data[5] & YEARS_REG_MSK)) + 100;
140 tm->tm_wday = bcd2bin(rtc_data[6] & WEEKS_REG_MSK);
141 rockchip_to_gregorian(tm);
142 dev_dbg(dev, "RTC date/time %ptRd(%d) %ptRt\n", tm, tm->tm_wday, tm);
143
144 return ret;
145 }
146
147 /* Set current time and date in RTC */
148 static int rk808_rtc_set_time(struct device *dev, struct rtc_time *tm)
149 {
150 struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
151 struct rk808 *rk808 = rk808_rtc->rk808;
152 u8 rtc_data[NUM_TIME_REGS];
153 int ret;
154
155 dev_dbg(dev, "set RTC date/time %ptRd(%d) %ptRt\n", tm, tm->tm_wday, tm);
156 gregorian_to_rockchip(tm);
157 rtc_data[0] = bin2bcd(tm->tm_sec);
158 rtc_data[1] = bin2bcd(tm->tm_min);
159 rtc_data[2] = bin2bcd(tm->tm_hour);
160 rtc_data[3] = bin2bcd(tm->tm_mday);
161 rtc_data[4] = bin2bcd(tm->tm_mon + 1);
162 rtc_data[5] = bin2bcd(tm->tm_year - 100);
163 rtc_data[6] = bin2bcd(tm->tm_wday);
164
165 /* Stop RTC while updating the RTC registers */
166 ret = regmap_update_bits(rk808->regmap, rk808_rtc->creg->ctrl_reg,
167 BIT_RTC_CTRL_REG_STOP_RTC_M,
168 BIT_RTC_CTRL_REG_STOP_RTC_M);
169 if (ret) {
170 dev_err(dev, "Failed to update RTC control: %d\n", ret);
171 return ret;
172 }
173
174 ret = regmap_bulk_write(rk808->regmap, rk808_rtc->creg->seconds_reg,
175 rtc_data, NUM_TIME_REGS);
176 if (ret) {
177 dev_err(dev, "Failed to bull write rtc_data: %d\n", ret);
178 return ret;
179 }
180 /* Start RTC again */
181 ret = regmap_update_bits(rk808->regmap, rk808_rtc->creg->ctrl_reg,
182 BIT_RTC_CTRL_REG_STOP_RTC_M, 0);
183 if (ret) {
184 dev_err(dev, "Failed to update RTC control: %d\n", ret);
185 return ret;
186 }
187 return 0;
188 }
189
190 /* Read alarm time and date in RTC */
191 static int rk808_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
192 {
193 struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
194 struct rk808 *rk808 = rk808_rtc->rk808;
195 u8 alrm_data[NUM_ALARM_REGS];
196 uint32_t int_reg;
197 int ret;
198
199 ret = regmap_bulk_read(rk808->regmap,
200 rk808_rtc->creg->alarm_seconds_reg,
201 alrm_data, NUM_ALARM_REGS);
202 if (ret) {
203 dev_err(dev, "Failed to read RTC alarm date REG: %d\n", ret);
204 return ret;
205 }
206
207 alrm->time.tm_sec = bcd2bin(alrm_data[0] & SECONDS_REG_MSK);
208 alrm->time.tm_min = bcd2bin(alrm_data[1] & MINUTES_REG_MAK);
209 alrm->time.tm_hour = bcd2bin(alrm_data[2] & HOURS_REG_MSK);
210 alrm->time.tm_mday = bcd2bin(alrm_data[3] & DAYS_REG_MSK);
211 alrm->time.tm_mon = (bcd2bin(alrm_data[4] & MONTHS_REG_MSK)) - 1;
212 alrm->time.tm_year = (bcd2bin(alrm_data[5] & YEARS_REG_MSK)) + 100;
213 rockchip_to_gregorian(&alrm->time);
214
215 ret = regmap_read(rk808->regmap, rk808_rtc->creg->int_reg, &int_reg);
216 if (ret) {
217 dev_err(dev, "Failed to read RTC INT REG: %d\n", ret);
218 return ret;
219 }
220
221 dev_dbg(dev, "alrm read RTC date/time %ptRd(%d) %ptRt\n",
222 &alrm->time, alrm->time.tm_wday, &alrm->time);
223
224 alrm->enabled = (int_reg & BIT_RTC_INTERRUPTS_REG_IT_ALARM_M) ? 1 : 0;
225
226 return 0;
227 }
228
229 static int rk808_rtc_stop_alarm(struct rk808_rtc *rk808_rtc)
230 {
231 struct rk808 *rk808 = rk808_rtc->rk808;
232 int ret;
233
234 ret = regmap_update_bits(rk808->regmap, rk808_rtc->creg->int_reg,
235 BIT_RTC_INTERRUPTS_REG_IT_ALARM_M, 0);
236
237 return ret;
238 }
239
240 static int rk808_rtc_start_alarm(struct rk808_rtc *rk808_rtc)
241 {
242 struct rk808 *rk808 = rk808_rtc->rk808;
243 int ret;
244
245 ret = regmap_update_bits(rk808->regmap, rk808_rtc->creg->int_reg,
246 BIT_RTC_INTERRUPTS_REG_IT_ALARM_M,
247 BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
248
249 return ret;
250 }
251
252 static int rk808_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
253 {
254 struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
255 struct rk808 *rk808 = rk808_rtc->rk808;
256 u8 alrm_data[NUM_ALARM_REGS];
257 int ret;
258
259 ret = rk808_rtc_stop_alarm(rk808_rtc);
260 if (ret) {
261 dev_err(dev, "Failed to stop alarm: %d\n", ret);
262 return ret;
263 }
264 dev_dbg(dev, "alrm set RTC date/time %ptRd(%d) %ptRt\n",
265 &alrm->time, alrm->time.tm_wday, &alrm->time);
266
267 gregorian_to_rockchip(&alrm->time);
268 alrm_data[0] = bin2bcd(alrm->time.tm_sec);
269 alrm_data[1] = bin2bcd(alrm->time.tm_min);
270 alrm_data[2] = bin2bcd(alrm->time.tm_hour);
271 alrm_data[3] = bin2bcd(alrm->time.tm_mday);
272 alrm_data[4] = bin2bcd(alrm->time.tm_mon + 1);
273 alrm_data[5] = bin2bcd(alrm->time.tm_year - 100);
274
275 ret = regmap_bulk_write(rk808->regmap,
276 rk808_rtc->creg->alarm_seconds_reg,
277 alrm_data, NUM_ALARM_REGS);
278 if (ret) {
279 dev_err(dev, "Failed to bulk write: %d\n", ret);
280 return ret;
281 }
282 if (alrm->enabled) {
283 ret = rk808_rtc_start_alarm(rk808_rtc);
284 if (ret) {
285 dev_err(dev, "Failed to start alarm: %d\n", ret);
286 return ret;
287 }
288 }
289 return 0;
290 }
291
292 static int rk808_rtc_alarm_irq_enable(struct device *dev,
293 unsigned int enabled)
294 {
295 struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
296
297 if (enabled)
298 return rk808_rtc_start_alarm(rk808_rtc);
299
300 return rk808_rtc_stop_alarm(rk808_rtc);
301 }
302
303 /*
304 * We will just handle setting the frequency and make use the framework for
305 * reading the periodic interupts.
306 *
307 * @freq: Current periodic IRQ freq:
308 * bit 0: every second
309 * bit 1: every minute
310 * bit 2: every hour
311 * bit 3: every day
312 */
313 static irqreturn_t rk808_alarm_irq(int irq, void *data)
314 {
315 struct rk808_rtc *rk808_rtc = data;
316 struct rk808 *rk808 = rk808_rtc->rk808;
317 struct i2c_client *client = rk808->i2c;
318 int ret;
319
320 ret = regmap_write(rk808->regmap, rk808_rtc->creg->status_reg,
321 RTC_STATUS_MASK);
322 if (ret) {
323 dev_err(&client->dev,
324 "%s:Failed to update RTC status: %d\n", __func__, ret);
325 return ret;
326 }
327
328 rtc_update_irq(rk808_rtc->rtc, 1, RTC_IRQF | RTC_AF);
329 dev_dbg(&client->dev,
330 "%s:irq=%d\n", __func__, irq);
331 return IRQ_HANDLED;
332 }
333
334 static const struct rtc_class_ops rk808_rtc_ops = {
335 .read_time = rk808_rtc_readtime,
336 .set_time = rk808_rtc_set_time,
337 .read_alarm = rk808_rtc_readalarm,
338 .set_alarm = rk808_rtc_setalarm,
339 .alarm_irq_enable = rk808_rtc_alarm_irq_enable,
340 };
341
342 #ifdef CONFIG_PM_SLEEP
343 /* Turn off the alarm if it should not be a wake source. */
344 static int rk808_rtc_suspend(struct device *dev)
345 {
346 struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
347
348 if (device_may_wakeup(dev))
349 enable_irq_wake(rk808_rtc->irq);
350
351 return 0;
352 }
353
354 /* Enable the alarm if it should be enabled (in case it was disabled to
355 * prevent use as a wake source).
356 */
357 static int rk808_rtc_resume(struct device *dev)
358 {
359 struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
360
361 if (device_may_wakeup(dev))
362 disable_irq_wake(rk808_rtc->irq);
363
364 return 0;
365 }
366 #endif
367
368 static SIMPLE_DEV_PM_OPS(rk808_rtc_pm_ops,
369 rk808_rtc_suspend, rk808_rtc_resume);
370
371 static struct rk_rtc_compat_reg rk808_creg = {
372 .ctrl_reg = RK808_RTC_CTRL_REG,
373 .status_reg = RK808_RTC_STATUS_REG,
374 .alarm_seconds_reg = RK808_ALARM_SECONDS_REG,
375 .int_reg = RK808_RTC_INT_REG,
376 .seconds_reg = RK808_SECONDS_REG,
377 };
378
379 static struct rk_rtc_compat_reg rk817_creg = {
380 .ctrl_reg = RK817_RTC_CTRL_REG,
381 .status_reg = RK817_RTC_STATUS_REG,
382 .alarm_seconds_reg = RK817_ALARM_SECONDS_REG,
383 .int_reg = RK817_RTC_INT_REG,
384 .seconds_reg = RK817_SECONDS_REG,
385 };
386
387 static int rk808_rtc_probe(struct platform_device *pdev)
388 {
389 struct rk808 *rk808 = dev_get_drvdata(pdev->dev.parent);
390 struct rk808_rtc *rk808_rtc;
391 int ret;
392
393 rk808_rtc = devm_kzalloc(&pdev->dev, sizeof(*rk808_rtc), GFP_KERNEL);
394 if (rk808_rtc == NULL)
395 return -ENOMEM;
396
397 switch (rk808->variant) {
398 case RK809_ID:
399 case RK817_ID:
400 rk808_rtc->creg = &rk817_creg;
401 break;
402 default:
403 rk808_rtc->creg = &rk808_creg;
404 break;
405 }
406 platform_set_drvdata(pdev, rk808_rtc);
407 rk808_rtc->rk808 = rk808;
408
409 /* start rtc running by default, and use shadowed timer. */
410 ret = regmap_update_bits(rk808->regmap, rk808_rtc->creg->ctrl_reg,
411 BIT_RTC_CTRL_REG_STOP_RTC_M |
412 BIT_RTC_CTRL_REG_RTC_READSEL_M,
413 BIT_RTC_CTRL_REG_RTC_READSEL_M);
414 if (ret) {
415 dev_err(&pdev->dev,
416 "Failed to update RTC control: %d\n", ret);
417 return ret;
418 }
419
420 ret = regmap_write(rk808->regmap, rk808_rtc->creg->status_reg,
421 RTC_STATUS_MASK);
422 if (ret) {
423 dev_err(&pdev->dev,
424 "Failed to write RTC status: %d\n", ret);
425 return ret;
426 }
427
428 device_init_wakeup(&pdev->dev, 1);
429
430 rk808_rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
431 if (IS_ERR(rk808_rtc->rtc))
432 return PTR_ERR(rk808_rtc->rtc);
433
434 rk808_rtc->rtc->ops = &rk808_rtc_ops;
435
436 rk808_rtc->irq = platform_get_irq(pdev, 0);
437 if (rk808_rtc->irq < 0)
438 return rk808_rtc->irq;
439
440 /* request alarm irq of rk808 */
441 ret = devm_request_threaded_irq(&pdev->dev, rk808_rtc->irq, NULL,
442 rk808_alarm_irq, 0,
443 "RTC alarm", rk808_rtc);
444 if (ret) {
445 dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n",
446 rk808_rtc->irq, ret);
447 return ret;
448 }
449
450 return rtc_register_device(rk808_rtc->rtc);
451 }
452
453 static struct platform_driver rk808_rtc_driver = {
454 .probe = rk808_rtc_probe,
455 .driver = {
456 .name = "rk808-rtc",
457 .pm = &rk808_rtc_pm_ops,
458 },
459 };
460
461 module_platform_driver(rk808_rtc_driver);
462
463 MODULE_DESCRIPTION("RTC driver for the rk808 series PMICs");
464 MODULE_AUTHOR("Chris Zhong <zyw@rock-chips.com>");
465 MODULE_AUTHOR("Zhang Qing <zhangqing@rock-chips.com>");
466 MODULE_LICENSE("GPL");
467 MODULE_ALIAS("platform:rk808-rtc");
Linux with added FPC-III support