1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * rtc-tps65910.c -- TPS65910 Real Time Clock interface
4 *
5 * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
6 * Author: Venu Byravarasu <vbyravarasu@nvidia.com>
7 *
8 * Based on original TI driver rtc-twl.c
9 * Copyright (C) 2007 MontaVista Software, Inc
10 * Author: Alexandre Rusev <source@mvista.com>
11 */
12
13 #include <linux/kernel.h>
14 #include <linux/errno.h>
15 #include <linux/init.h>
16 #include <linux/module.h>
17 #include <linux/types.h>
18 #include <linux/rtc.h>
19 #include <linux/bcd.h>
20 #include <linux/math64.h>
21 #include <linux/property.h>
22 #include <linux/platform_device.h>
23 #include <linux/interrupt.h>
24 #include <linux/mfd/tps65910.h>
25
26 struct tps65910_rtc {
27 struct rtc_device *rtc;
28 int irq;
29 };
30
31 /* Total number of RTC registers needed to set time*/
32 #define NUM_TIME_REGS (TPS65910_YEARS - TPS65910_SECONDS + 1)
33
34 /* Total number of RTC registers needed to set compensation registers */
35 #define NUM_COMP_REGS (TPS65910_RTC_COMP_MSB - TPS65910_RTC_COMP_LSB + 1)
36
37 /* Min and max values supported with 'offset' interface (swapped sign) */
38 #define MIN_OFFSET (-277761)
39 #define MAX_OFFSET (277778)
40
41 /* Number of ticks per hour */
42 #define TICKS_PER_HOUR (32768 * 3600)
43
44 /* Multiplier for ppb conversions */
45 #define PPB_MULT (1000000000LL)
46
tps65910_rtc_alarm_irq_enable(struct device * dev,unsigned int enabled)47 static int tps65910_rtc_alarm_irq_enable(struct device *dev,
48 unsigned int enabled)
49 {
50 struct tps65910 *tps = dev_get_drvdata(dev->parent);
51 u8 val = 0;
52
53 if (enabled)
54 val = TPS65910_RTC_INTERRUPTS_IT_ALARM;
55
56 return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS, val);
57 }
58
59 /*
60 * Gets current tps65910 RTC time and date parameters.
61 *
62 * The RTC's time/alarm representation is not what gmtime(3) requires
63 * Linux to use:
64 *
65 * - Months are 1..12 vs Linux 0-11
66 * - Years are 0..99 vs Linux 1900..N (we assume 21st century)
67 */
tps65910_rtc_read_time(struct device * dev,struct rtc_time * tm)68 static int tps65910_rtc_read_time(struct device *dev, struct rtc_time *tm)
69 {
70 unsigned char rtc_data[NUM_TIME_REGS];
71 struct tps65910 *tps = dev_get_drvdata(dev->parent);
72 int ret;
73
74 /* Copy RTC counting registers to static registers or latches */
75 ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
76 TPS65910_RTC_CTRL_GET_TIME, TPS65910_RTC_CTRL_GET_TIME);
77 if (ret < 0) {
78 dev_err(dev, "RTC CTRL reg update failed with err:%d\n", ret);
79 return ret;
80 }
81
82 ret = regmap_bulk_read(tps->regmap, TPS65910_SECONDS, rtc_data,
83 NUM_TIME_REGS);
84 if (ret < 0) {
85 dev_err(dev, "reading from RTC failed with err:%d\n", ret);
86 return ret;
87 }
88
89 tm->tm_sec = bcd2bin(rtc_data[0]);
90 tm->tm_min = bcd2bin(rtc_data[1]);
91 tm->tm_hour = bcd2bin(rtc_data[2]);
92 tm->tm_mday = bcd2bin(rtc_data[3]);
93 tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
94 tm->tm_year = bcd2bin(rtc_data[5]) + 100;
95
96 return ret;
97 }
98
tps65910_rtc_set_time(struct device * dev,struct rtc_time * tm)99 static int tps65910_rtc_set_time(struct device *dev, struct rtc_time *tm)
100 {
101 unsigned char rtc_data[NUM_TIME_REGS];
102 struct tps65910 *tps = dev_get_drvdata(dev->parent);
103 int ret;
104
105 rtc_data[0] = bin2bcd(tm->tm_sec);
106 rtc_data[1] = bin2bcd(tm->tm_min);
107 rtc_data[2] = bin2bcd(tm->tm_hour);
108 rtc_data[3] = bin2bcd(tm->tm_mday);
109 rtc_data[4] = bin2bcd(tm->tm_mon + 1);
110 rtc_data[5] = bin2bcd(tm->tm_year - 100);
111
112 /* Stop RTC while updating the RTC time registers */
113 ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
114 TPS65910_RTC_CTRL_STOP_RTC, 0);
115 if (ret < 0) {
116 dev_err(dev, "RTC stop failed with err:%d\n", ret);
117 return ret;
118 }
119
120 /* update all the time registers in one shot */
121 ret = regmap_bulk_write(tps->regmap, TPS65910_SECONDS, rtc_data,
122 NUM_TIME_REGS);
123 if (ret < 0) {
124 dev_err(dev, "rtc_set_time error %d\n", ret);
125 return ret;
126 }
127
128 /* Start back RTC */
129 ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
130 TPS65910_RTC_CTRL_STOP_RTC, 1);
131 if (ret < 0)
132 dev_err(dev, "RTC start failed with err:%d\n", ret);
133
134 return ret;
135 }
136
137 /*
138 * Gets current tps65910 RTC alarm time.
139 */
tps65910_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alm)140 static int tps65910_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
141 {
142 unsigned char alarm_data[NUM_TIME_REGS];
143 u32 int_val;
144 struct tps65910 *tps = dev_get_drvdata(dev->parent);
145 int ret;
146
147 ret = regmap_bulk_read(tps->regmap, TPS65910_ALARM_SECONDS, alarm_data,
148 NUM_TIME_REGS);
149 if (ret < 0) {
150 dev_err(dev, "rtc_read_alarm error %d\n", ret);
151 return ret;
152 }
153
154 alm->time.tm_sec = bcd2bin(alarm_data[0]);
155 alm->time.tm_min = bcd2bin(alarm_data[1]);
156 alm->time.tm_hour = bcd2bin(alarm_data[2]);
157 alm->time.tm_mday = bcd2bin(alarm_data[3]);
158 alm->time.tm_mon = bcd2bin(alarm_data[4]) - 1;
159 alm->time.tm_year = bcd2bin(alarm_data[5]) + 100;
160
161 ret = regmap_read(tps->regmap, TPS65910_RTC_INTERRUPTS, &int_val);
162 if (ret < 0)
163 return ret;
164
165 if (int_val & TPS65910_RTC_INTERRUPTS_IT_ALARM)
166 alm->enabled = 1;
167
168 return ret;
169 }
170
tps65910_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alm)171 static int tps65910_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
172 {
173 unsigned char alarm_data[NUM_TIME_REGS];
174 struct tps65910 *tps = dev_get_drvdata(dev->parent);
175 int ret;
176
177 ret = tps65910_rtc_alarm_irq_enable(dev, 0);
178 if (ret)
179 return ret;
180
181 alarm_data[0] = bin2bcd(alm->time.tm_sec);
182 alarm_data[1] = bin2bcd(alm->time.tm_min);
183 alarm_data[2] = bin2bcd(alm->time.tm_hour);
184 alarm_data[3] = bin2bcd(alm->time.tm_mday);
185 alarm_data[4] = bin2bcd(alm->time.tm_mon + 1);
186 alarm_data[5] = bin2bcd(alm->time.tm_year - 100);
187
188 /* update all the alarm registers in one shot */
189 ret = regmap_bulk_write(tps->regmap, TPS65910_ALARM_SECONDS,
190 alarm_data, NUM_TIME_REGS);
191 if (ret) {
192 dev_err(dev, "rtc_set_alarm error %d\n", ret);
193 return ret;
194 }
195
196 if (alm->enabled)
197 ret = tps65910_rtc_alarm_irq_enable(dev, 1);
198
199 return ret;
200 }
201
tps65910_rtc_set_calibration(struct device * dev,int calibration)202 static int tps65910_rtc_set_calibration(struct device *dev, int calibration)
203 {
204 unsigned char comp_data[NUM_COMP_REGS];
205 struct tps65910 *tps = dev_get_drvdata(dev->parent);
206 s16 value;
207 int ret;
208
209 /*
210 * TPS65910 uses two's complement 16 bit value for compensation for RTC
211 * crystal inaccuracies. One time every hour when seconds counter
212 * increments from 0 to 1 compensation value will be added to internal
213 * RTC counter value.
214 *
215 * Compensation value 0x7FFF is prohibited value.
216 *
217 * Valid range for compensation value: [-32768 .. 32766]
218 */
219 if ((calibration < -32768) || (calibration > 32766)) {
220 dev_err(dev, "RTC calibration value out of range: %d\n",
221 calibration);
222 return -EINVAL;
223 }
224
225 value = (s16)calibration;
226
227 comp_data[0] = (u16)value & 0xFF;
228 comp_data[1] = ((u16)value >> 8) & 0xFF;
229
230 /* Update all the compensation registers in one shot */
231 ret = regmap_bulk_write(tps->regmap, TPS65910_RTC_COMP_LSB,
232 comp_data, NUM_COMP_REGS);
233 if (ret < 0) {
234 dev_err(dev, "rtc_set_calibration error: %d\n", ret);
235 return ret;
236 }
237
238 /* Enable automatic compensation */
239 ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
240 TPS65910_RTC_CTRL_AUTO_COMP, TPS65910_RTC_CTRL_AUTO_COMP);
241 if (ret < 0)
242 dev_err(dev, "auto_comp enable failed with error: %d\n", ret);
243
244 return ret;
245 }
246
tps65910_rtc_get_calibration(struct device * dev,int * calibration)247 static int tps65910_rtc_get_calibration(struct device *dev, int *calibration)
248 {
249 unsigned char comp_data[NUM_COMP_REGS];
250 struct tps65910 *tps = dev_get_drvdata(dev->parent);
251 unsigned int ctrl;
252 u16 value;
253 int ret;
254
255 ret = regmap_read(tps->regmap, TPS65910_RTC_CTRL, &ctrl);
256 if (ret < 0)
257 return ret;
258
259 /* If automatic compensation is not enabled report back zero */
260 if (!(ctrl & TPS65910_RTC_CTRL_AUTO_COMP)) {
261 *calibration = 0;
262 return 0;
263 }
264
265 ret = regmap_bulk_read(tps->regmap, TPS65910_RTC_COMP_LSB, comp_data,
266 NUM_COMP_REGS);
267 if (ret < 0) {
268 dev_err(dev, "rtc_get_calibration error: %d\n", ret);
269 return ret;
270 }
271
272 value = (u16)comp_data[0] | ((u16)comp_data[1] << 8);
273
274 *calibration = (s16)value;
275
276 return 0;
277 }
278
tps65910_read_offset(struct device * dev,long * offset)279 static int tps65910_read_offset(struct device *dev, long *offset)
280 {
281 int calibration;
282 s64 tmp;
283 int ret;
284
285 ret = tps65910_rtc_get_calibration(dev, &calibration);
286 if (ret < 0)
287 return ret;
288
289 /* Convert from RTC calibration register format to ppb format */
290 tmp = calibration * (s64)PPB_MULT;
291 if (tmp < 0)
292 tmp -= TICKS_PER_HOUR / 2LL;
293 else
294 tmp += TICKS_PER_HOUR / 2LL;
295 tmp = div_s64(tmp, TICKS_PER_HOUR);
296
297 /* Offset value operates in negative way, so swap sign */
298 *offset = (long)-tmp;
299
300 return 0;
301 }
302
tps65910_set_offset(struct device * dev,long offset)303 static int tps65910_set_offset(struct device *dev, long offset)
304 {
305 int calibration;
306 s64 tmp;
307 int ret;
308
309 /* Make sure offset value is within supported range */
310 if (offset < MIN_OFFSET || offset > MAX_OFFSET)
311 return -ERANGE;
312
313 /* Convert from ppb format to RTC calibration register format */
314 tmp = offset * (s64)TICKS_PER_HOUR;
315 if (tmp < 0)
316 tmp -= PPB_MULT / 2LL;
317 else
318 tmp += PPB_MULT / 2LL;
319 tmp = div_s64(tmp, PPB_MULT);
320
321 /* Offset value operates in negative way, so swap sign */
322 calibration = (int)-tmp;
323
324 ret = tps65910_rtc_set_calibration(dev, calibration);
325
326 return ret;
327 }
328
tps65910_rtc_interrupt(int irq,void * rtc)329 static irqreturn_t tps65910_rtc_interrupt(int irq, void *rtc)
330 {
331 struct device *dev = rtc;
332 unsigned long events = 0;
333 struct tps65910 *tps = dev_get_drvdata(dev->parent);
334 struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
335 int ret;
336 u32 rtc_reg;
337
338 ret = regmap_read(tps->regmap, TPS65910_RTC_STATUS, &rtc_reg);
339 if (ret)
340 return IRQ_NONE;
341
342 if (rtc_reg & TPS65910_RTC_STATUS_ALARM)
343 events = RTC_IRQF | RTC_AF;
344
345 ret = regmap_write(tps->regmap, TPS65910_RTC_STATUS, rtc_reg);
346 if (ret)
347 return IRQ_NONE;
348
349 /* Notify RTC core on event */
350 rtc_update_irq(tps_rtc->rtc, 1, events);
351
352 return IRQ_HANDLED;
353 }
354
355 static const struct rtc_class_ops tps65910_rtc_ops = {
356 .read_time = tps65910_rtc_read_time,
357 .set_time = tps65910_rtc_set_time,
358 .read_alarm = tps65910_rtc_read_alarm,
359 .set_alarm = tps65910_rtc_set_alarm,
360 .alarm_irq_enable = tps65910_rtc_alarm_irq_enable,
361 .read_offset = tps65910_read_offset,
362 .set_offset = tps65910_set_offset,
363 };
364
tps65910_rtc_probe(struct platform_device * pdev)365 static int tps65910_rtc_probe(struct platform_device *pdev)
366 {
367 struct tps65910 *tps65910 = NULL;
368 struct tps65910_rtc *tps_rtc = NULL;
369 int ret;
370 int irq;
371 u32 rtc_reg;
372
373 tps65910 = dev_get_drvdata(pdev->dev.parent);
374
375 tps_rtc = devm_kzalloc(&pdev->dev, sizeof(struct tps65910_rtc),
376 GFP_KERNEL);
377 if (!tps_rtc)
378 return -ENOMEM;
379
380 tps_rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
381 if (IS_ERR(tps_rtc->rtc))
382 return PTR_ERR(tps_rtc->rtc);
383
384 /* Clear pending interrupts */
385 ret = regmap_read(tps65910->regmap, TPS65910_RTC_STATUS, &rtc_reg);
386 if (ret < 0)
387 return ret;
388
389 ret = regmap_write(tps65910->regmap, TPS65910_RTC_STATUS, rtc_reg);
390 if (ret < 0)
391 return ret;
392
393 dev_dbg(&pdev->dev, "Enabling rtc-tps65910.\n");
394
395 /* Enable RTC digital power domain */
396 ret = regmap_update_bits(tps65910->regmap, TPS65910_DEVCTRL,
397 DEVCTRL_RTC_PWDN_MASK, 0 << DEVCTRL_RTC_PWDN_SHIFT);
398 if (ret < 0)
399 return ret;
400
401 rtc_reg = TPS65910_RTC_CTRL_STOP_RTC;
402 ret = regmap_write(tps65910->regmap, TPS65910_RTC_CTRL, rtc_reg);
403 if (ret < 0)
404 return ret;
405
406 platform_set_drvdata(pdev, tps_rtc);
407
408 irq = platform_get_irq(pdev, 0);
409 if (irq < 0)
410 return irq;
411
412 ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
413 tps65910_rtc_interrupt, IRQF_TRIGGER_LOW,
414 dev_name(&pdev->dev), &pdev->dev);
415 if (ret < 0)
416 irq = -1;
417
418 tps_rtc->irq = irq;
419 if (irq != -1) {
420 if (device_property_present(tps65910->dev, "wakeup-source"))
421 device_init_wakeup(&pdev->dev, 1);
422 else
423 device_set_wakeup_capable(&pdev->dev, 1);
424 } else {
425 clear_bit(RTC_FEATURE_ALARM, tps_rtc->rtc->features);
426 }
427
428 tps_rtc->rtc->ops = &tps65910_rtc_ops;
429 tps_rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
430 tps_rtc->rtc->range_max = RTC_TIMESTAMP_END_2099;
431
432 return devm_rtc_register_device(tps_rtc->rtc);
433 }
434
435 #ifdef CONFIG_PM_SLEEP
tps65910_rtc_suspend(struct device * dev)436 static int tps65910_rtc_suspend(struct device *dev)
437 {
438 struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
439
440 if (device_may_wakeup(dev))
441 enable_irq_wake(tps_rtc->irq);
442 return 0;
443 }
444
tps65910_rtc_resume(struct device * dev)445 static int tps65910_rtc_resume(struct device *dev)
446 {
447 struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
448
449 if (device_may_wakeup(dev))
450 disable_irq_wake(tps_rtc->irq);
451 return 0;
452 }
453 #endif
454
455 static SIMPLE_DEV_PM_OPS(tps65910_rtc_pm_ops, tps65910_rtc_suspend,
456 tps65910_rtc_resume);
457
458 static struct platform_driver tps65910_rtc_driver = {
459 .probe = tps65910_rtc_probe,
460 .driver = {
461 .name = "tps65910-rtc",
462 .pm = &tps65910_rtc_pm_ops,
463 },
464 };
465
466 module_platform_driver(tps65910_rtc_driver);
467 MODULE_ALIAS("platform:tps65910-rtc");
468 MODULE_AUTHOR("Venu Byravarasu <vbyravarasu@nvidia.com>");
469 MODULE_LICENSE("GPL");
470