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1/* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
2 *
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License version 2 and
5 * only version 2 as published by the Free Software Foundation.
6 *
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
11 */
12
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/rtc.h>
16#include <linux/pm.h>
17#include <linux/slab.h>
18#include <linux/spinlock.h>
19
20#include <linux/mfd/pm8xxx/core.h>
21#include <linux/mfd/pm8xxx/rtc.h>
22
23
24/* RTC Register offsets from RTC CTRL REG */
25#define PM8XXX_ALARM_CTRL_OFFSET 0x01
26#define PM8XXX_RTC_WRITE_OFFSET 0x02
27#define PM8XXX_RTC_READ_OFFSET 0x06
28#define PM8XXX_ALARM_RW_OFFSET 0x0A
29
30/* RTC_CTRL register bit fields */
31#define PM8xxx_RTC_ENABLE BIT(7)
32#define PM8xxx_RTC_ALARM_ENABLE BIT(1)
33#define PM8xxx_RTC_ALARM_CLEAR BIT(0)
34
35#define NUM_8_BIT_RTC_REGS 0x4
36
37/**
38 * struct pm8xxx_rtc - rtc driver internal structure
39 * @rtc: rtc device for this driver.
40 * @rtc_alarm_irq: rtc alarm irq number.
41 * @rtc_base: address of rtc control register.
42 * @rtc_read_base: base address of read registers.
43 * @rtc_write_base: base address of write registers.
44 * @alarm_rw_base: base address of alarm registers.
45 * @ctrl_reg: rtc control register.
46 * @rtc_dev: device structure.
47 * @ctrl_reg_lock: spinlock protecting access to ctrl_reg.
48 */
49struct pm8xxx_rtc {
50 struct rtc_device *rtc;
51 int rtc_alarm_irq;
52 int rtc_base;
53 int rtc_read_base;
54 int rtc_write_base;
55 int alarm_rw_base;
56 u8 ctrl_reg;
57 struct device *rtc_dev;
58 spinlock_t ctrl_reg_lock;
59};
60
61/*
62 * The RTC registers need to be read/written one byte at a time. This is a
63 * hardware limitation.
64 */
65static int pm8xxx_read_wrapper(struct pm8xxx_rtc *rtc_dd, u8 *rtc_val,
66 int base, int count)
67{
68 int i, rc;
69 struct device *parent = rtc_dd->rtc_dev->parent;
70
71 for (i = 0; i < count; i++) {
72 rc = pm8xxx_readb(parent, base + i, &rtc_val[i]);
73 if (rc < 0) {
74 dev_err(rtc_dd->rtc_dev, "PMIC read failed\n");
75 return rc;
76 }
77 }
78
79 return 0;
80}
81
82static int pm8xxx_write_wrapper(struct pm8xxx_rtc *rtc_dd, u8 *rtc_val,
83 int base, int count)
84{
85 int i, rc;
86 struct device *parent = rtc_dd->rtc_dev->parent;
87
88 for (i = 0; i < count; i++) {
89 rc = pm8xxx_writeb(parent, base + i, rtc_val[i]);
90 if (rc < 0) {
91 dev_err(rtc_dd->rtc_dev, "PMIC write failed\n");
92 return rc;
93 }
94 }
95
96 return 0;
97}
98
99/*
100 * Steps to write the RTC registers.
101 * 1. Disable alarm if enabled.
102 * 2. Write 0x00 to LSB.
103 * 3. Write Byte[1], Byte[2], Byte[3] then Byte[0].
104 * 4. Enable alarm if disabled in step 1.
105 */
106static int pm8xxx_rtc_set_time(struct device *dev, struct rtc_time *tm)
107{
108 int rc, i;
109 unsigned long secs, irq_flags;
110 u8 value[NUM_8_BIT_RTC_REGS], reg = 0, alarm_enabled = 0, ctrl_reg;
111 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
112
113 rtc_tm_to_time(tm, &secs);
114
115 for (i = 0; i < NUM_8_BIT_RTC_REGS; i++) {
116 value[i] = secs & 0xFF;
117 secs >>= 8;
118 }
119
120 dev_dbg(dev, "Seconds value to be written to RTC = %lu\n", secs);
121
122 spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
123 ctrl_reg = rtc_dd->ctrl_reg;
124
125 if (ctrl_reg & PM8xxx_RTC_ALARM_ENABLE) {
126 alarm_enabled = 1;
127 ctrl_reg &= ~PM8xxx_RTC_ALARM_ENABLE;
128 rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base,
129 1);
130 if (rc < 0) {
131 dev_err(dev, "Write to RTC control register "
132 "failed\n");
133 goto rtc_rw_fail;
134 }
135 rtc_dd->ctrl_reg = ctrl_reg;
136 } else
137 spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
138
139 /* Write 0 to Byte[0] */
140 reg = 0;
141 rc = pm8xxx_write_wrapper(rtc_dd, ®, rtc_dd->rtc_write_base, 1);
142 if (rc < 0) {
143 dev_err(dev, "Write to RTC write data register failed\n");
144 goto rtc_rw_fail;
145 }
146
147 /* Write Byte[1], Byte[2], Byte[3] */
148 rc = pm8xxx_write_wrapper(rtc_dd, value + 1,
149 rtc_dd->rtc_write_base + 1, 3);
150 if (rc < 0) {
151 dev_err(dev, "Write to RTC write data register failed\n");
152 goto rtc_rw_fail;
153 }
154
155 /* Write Byte[0] */
156 rc = pm8xxx_write_wrapper(rtc_dd, value, rtc_dd->rtc_write_base, 1);
157 if (rc < 0) {
158 dev_err(dev, "Write to RTC write data register failed\n");
159 goto rtc_rw_fail;
160 }
161
162 if (alarm_enabled) {
163 ctrl_reg |= PM8xxx_RTC_ALARM_ENABLE;
164 rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base,
165 1);
166 if (rc < 0) {
167 dev_err(dev, "Write to RTC control register "
168 "failed\n");
169 goto rtc_rw_fail;
170 }
171 rtc_dd->ctrl_reg = ctrl_reg;
172 }
173
174rtc_rw_fail:
175 if (alarm_enabled)
176 spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
177
178 return rc;
179}
180
181static int pm8xxx_rtc_read_time(struct device *dev, struct rtc_time *tm)
182{
183 int rc;
184 u8 value[NUM_8_BIT_RTC_REGS], reg;
185 unsigned long secs;
186 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
187
188 rc = pm8xxx_read_wrapper(rtc_dd, value, rtc_dd->rtc_read_base,
189 NUM_8_BIT_RTC_REGS);
190 if (rc < 0) {
191 dev_err(dev, "RTC read data register failed\n");
192 return rc;
193 }
194
195 /*
196 * Read the LSB again and check if there has been a carry over.
197 * If there is, redo the read operation.
198 */
199 rc = pm8xxx_read_wrapper(rtc_dd, ®, rtc_dd->rtc_read_base, 1);
200 if (rc < 0) {
201 dev_err(dev, "RTC read data register failed\n");
202 return rc;
203 }
204
205 if (unlikely(reg < value[0])) {
206 rc = pm8xxx_read_wrapper(rtc_dd, value,
207 rtc_dd->rtc_read_base, NUM_8_BIT_RTC_REGS);
208 if (rc < 0) {
209 dev_err(dev, "RTC read data register failed\n");
210 return rc;
211 }
212 }
213
214 secs = value[0] | (value[1] << 8) | (value[2] << 16) | (value[3] << 24);
215
216 rtc_time_to_tm(secs, tm);
217
218 rc = rtc_valid_tm(tm);
219 if (rc < 0) {
220 dev_err(dev, "Invalid time read from RTC\n");
221 return rc;
222 }
223
224 dev_dbg(dev, "secs = %lu, h:m:s == %d:%d:%d, d/m/y = %d/%d/%d\n",
225 secs, tm->tm_hour, tm->tm_min, tm->tm_sec,
226 tm->tm_mday, tm->tm_mon, tm->tm_year);
227
228 return 0;
229}
230
231static int pm8xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
232{
233 int rc, i;
234 u8 value[NUM_8_BIT_RTC_REGS], ctrl_reg;
235 unsigned long secs, irq_flags;
236 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
237
238 rtc_tm_to_time(&alarm->time, &secs);
239
240 for (i = 0; i < NUM_8_BIT_RTC_REGS; i++) {
241 value[i] = secs & 0xFF;
242 secs >>= 8;
243 }
244
245 spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
246
247 rc = pm8xxx_write_wrapper(rtc_dd, value, rtc_dd->alarm_rw_base,
248 NUM_8_BIT_RTC_REGS);
249 if (rc < 0) {
250 dev_err(dev, "Write to RTC ALARM register failed\n");
251 goto rtc_rw_fail;
252 }
253
254 ctrl_reg = rtc_dd->ctrl_reg;
255 ctrl_reg = alarm->enabled ? (ctrl_reg | PM8xxx_RTC_ALARM_ENABLE) :
256 (ctrl_reg & ~PM8xxx_RTC_ALARM_ENABLE);
257
258 rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base, 1);
259 if (rc < 0) {
260 dev_err(dev, "Write to RTC control register failed\n");
261 goto rtc_rw_fail;
262 }
263
264 rtc_dd->ctrl_reg = ctrl_reg;
265
266 dev_dbg(dev, "Alarm Set for h:r:s=%d:%d:%d, d/m/y=%d/%d/%d\n",
267 alarm->time.tm_hour, alarm->time.tm_min,
268 alarm->time.tm_sec, alarm->time.tm_mday,
269 alarm->time.tm_mon, alarm->time.tm_year);
270rtc_rw_fail:
271 spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
272 return rc;
273}
274
275static int pm8xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
276{
277 int rc;
278 u8 value[NUM_8_BIT_RTC_REGS];
279 unsigned long secs;
280 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
281
282 rc = pm8xxx_read_wrapper(rtc_dd, value, rtc_dd->alarm_rw_base,
283 NUM_8_BIT_RTC_REGS);
284 if (rc < 0) {
285 dev_err(dev, "RTC alarm time read failed\n");
286 return rc;
287 }
288
289 secs = value[0] | (value[1] << 8) | (value[2] << 16) | (value[3] << 24);
290
291 rtc_time_to_tm(secs, &alarm->time);
292
293 rc = rtc_valid_tm(&alarm->time);
294 if (rc < 0) {
295 dev_err(dev, "Invalid alarm time read from RTC\n");
296 return rc;
297 }
298
299 dev_dbg(dev, "Alarm set for - h:r:s=%d:%d:%d, d/m/y=%d/%d/%d\n",
300 alarm->time.tm_hour, alarm->time.tm_min,
301 alarm->time.tm_sec, alarm->time.tm_mday,
302 alarm->time.tm_mon, alarm->time.tm_year);
303
304 return 0;
305}
306
307static int pm8xxx_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
308{
309 int rc;
310 unsigned long irq_flags;
311 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
312 u8 ctrl_reg;
313
314 spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
315 ctrl_reg = rtc_dd->ctrl_reg;
316 ctrl_reg = (enable) ? (ctrl_reg | PM8xxx_RTC_ALARM_ENABLE) :
317 (ctrl_reg & ~PM8xxx_RTC_ALARM_ENABLE);
318
319 rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base, 1);
320 if (rc < 0) {
321 dev_err(dev, "Write to RTC control register failed\n");
322 goto rtc_rw_fail;
323 }
324
325 rtc_dd->ctrl_reg = ctrl_reg;
326
327rtc_rw_fail:
328 spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
329 return rc;
330}
331
332static struct rtc_class_ops pm8xxx_rtc_ops = {
333 .read_time = pm8xxx_rtc_read_time,
334 .set_alarm = pm8xxx_rtc_set_alarm,
335 .read_alarm = pm8xxx_rtc_read_alarm,
336 .alarm_irq_enable = pm8xxx_rtc_alarm_irq_enable,
337};
338
339static irqreturn_t pm8xxx_alarm_trigger(int irq, void *dev_id)
340{
341 struct pm8xxx_rtc *rtc_dd = dev_id;
342 u8 ctrl_reg;
343 int rc;
344 unsigned long irq_flags;
345
346 rtc_update_irq(rtc_dd->rtc, 1, RTC_IRQF | RTC_AF);
347
348 spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
349
350 /* Clear the alarm enable bit */
351 ctrl_reg = rtc_dd->ctrl_reg;
352 ctrl_reg &= ~PM8xxx_RTC_ALARM_ENABLE;
353
354 rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base, 1);
355 if (rc < 0) {
356 spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
357 dev_err(rtc_dd->rtc_dev, "Write to RTC control register "
358 "failed\n");
359 goto rtc_alarm_handled;
360 }
361
362 rtc_dd->ctrl_reg = ctrl_reg;
363 spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
364
365 /* Clear RTC alarm register */
366 rc = pm8xxx_read_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base +
367 PM8XXX_ALARM_CTRL_OFFSET, 1);
368 if (rc < 0) {
369 dev_err(rtc_dd->rtc_dev, "RTC Alarm control register read "
370 "failed\n");
371 goto rtc_alarm_handled;
372 }
373
374 ctrl_reg &= ~PM8xxx_RTC_ALARM_CLEAR;
375 rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base +
376 PM8XXX_ALARM_CTRL_OFFSET, 1);
377 if (rc < 0)
378 dev_err(rtc_dd->rtc_dev, "Write to RTC Alarm control register"
379 " failed\n");
380
381rtc_alarm_handled:
382 return IRQ_HANDLED;
383}
384
385static int __devinit pm8xxx_rtc_probe(struct platform_device *pdev)
386{
387 int rc;
388 u8 ctrl_reg;
389 bool rtc_write_enable = false;
390 struct pm8xxx_rtc *rtc_dd;
391 struct resource *rtc_resource;
392 const struct pm8xxx_rtc_platform_data *pdata =
393 dev_get_platdata(&pdev->dev);
394
395 if (pdata != NULL)
396 rtc_write_enable = pdata->rtc_write_enable;
397
398 rtc_dd = kzalloc(sizeof(*rtc_dd), GFP_KERNEL);
399 if (rtc_dd == NULL) {
400 dev_err(&pdev->dev, "Unable to allocate memory!\n");
401 return -ENOMEM;
402 }
403
404 /* Initialise spinlock to protect RTC control register */
405 spin_lock_init(&rtc_dd->ctrl_reg_lock);
406
407 rtc_dd->rtc_alarm_irq = platform_get_irq(pdev, 0);
408 if (rtc_dd->rtc_alarm_irq < 0) {
409 dev_err(&pdev->dev, "Alarm IRQ resource absent!\n");
410 rc = -ENXIO;
411 goto fail_rtc_enable;
412 }
413
414 rtc_resource = platform_get_resource_byname(pdev, IORESOURCE_IO,
415 "pmic_rtc_base");
416 if (!(rtc_resource && rtc_resource->start)) {
417 dev_err(&pdev->dev, "RTC IO resource absent!\n");
418 rc = -ENXIO;
419 goto fail_rtc_enable;
420 }
421
422 rtc_dd->rtc_base = rtc_resource->start;
423
424 /* Setup RTC register addresses */
425 rtc_dd->rtc_write_base = rtc_dd->rtc_base + PM8XXX_RTC_WRITE_OFFSET;
426 rtc_dd->rtc_read_base = rtc_dd->rtc_base + PM8XXX_RTC_READ_OFFSET;
427 rtc_dd->alarm_rw_base = rtc_dd->rtc_base + PM8XXX_ALARM_RW_OFFSET;
428
429 rtc_dd->rtc_dev = &pdev->dev;
430
431 /* Check if the RTC is on, else turn it on */
432 rc = pm8xxx_read_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base, 1);
433 if (rc < 0) {
434 dev_err(&pdev->dev, "RTC control register read failed!\n");
435 goto fail_rtc_enable;
436 }
437
438 if (!(ctrl_reg & PM8xxx_RTC_ENABLE)) {
439 ctrl_reg |= PM8xxx_RTC_ENABLE;
440 rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base,
441 1);
442 if (rc < 0) {
443 dev_err(&pdev->dev, "Write to RTC control register "
444 "failed\n");
445 goto fail_rtc_enable;
446 }
447 }
448
449 rtc_dd->ctrl_reg = ctrl_reg;
450 if (rtc_write_enable == true)
451 pm8xxx_rtc_ops.set_time = pm8xxx_rtc_set_time;
452
453 platform_set_drvdata(pdev, rtc_dd);
454
455 /* Register the RTC device */
456 rtc_dd->rtc = rtc_device_register("pm8xxx_rtc", &pdev->dev,
457 &pm8xxx_rtc_ops, THIS_MODULE);
458 if (IS_ERR(rtc_dd->rtc)) {
459 dev_err(&pdev->dev, "%s: RTC registration failed (%ld)\n",
460 __func__, PTR_ERR(rtc_dd->rtc));
461 rc = PTR_ERR(rtc_dd->rtc);
462 goto fail_rtc_enable;
463 }
464
465 /* Request the alarm IRQ */
466 rc = request_any_context_irq(rtc_dd->rtc_alarm_irq,
467 pm8xxx_alarm_trigger, IRQF_TRIGGER_RISING,
468 "pm8xxx_rtc_alarm", rtc_dd);
469 if (rc < 0) {
470 dev_err(&pdev->dev, "Request IRQ failed (%d)\n", rc);
471 goto fail_req_irq;
472 }
473
474 device_init_wakeup(&pdev->dev, 1);
475
476 dev_dbg(&pdev->dev, "Probe success !!\n");
477
478 return 0;
479
480fail_req_irq:
481 rtc_device_unregister(rtc_dd->rtc);
482fail_rtc_enable:
483 platform_set_drvdata(pdev, NULL);
484 kfree(rtc_dd);
485 return rc;
486}
487
488static int __devexit pm8xxx_rtc_remove(struct platform_device *pdev)
489{
490 struct pm8xxx_rtc *rtc_dd = platform_get_drvdata(pdev);
491
492 device_init_wakeup(&pdev->dev, 0);
493 free_irq(rtc_dd->rtc_alarm_irq, rtc_dd);
494 rtc_device_unregister(rtc_dd->rtc);
495 platform_set_drvdata(pdev, NULL);
496 kfree(rtc_dd);
497
498 return 0;
499}
500
501#ifdef CONFIG_PM_SLEEP
502static int pm8xxx_rtc_resume(struct device *dev)
503{
504 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
505
506 if (device_may_wakeup(dev))
507 disable_irq_wake(rtc_dd->rtc_alarm_irq);
508
509 return 0;
510}
511
512static int pm8xxx_rtc_suspend(struct device *dev)
513{
514 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
515
516 if (device_may_wakeup(dev))
517 enable_irq_wake(rtc_dd->rtc_alarm_irq);
518
519 return 0;
520}
521#endif
522
523static SIMPLE_DEV_PM_OPS(pm8xxx_rtc_pm_ops, pm8xxx_rtc_suspend, pm8xxx_rtc_resume);
524
525static struct platform_driver pm8xxx_rtc_driver = {
526 .probe = pm8xxx_rtc_probe,
527 .remove = __devexit_p(pm8xxx_rtc_remove),
528 .driver = {
529 .name = PM8XXX_RTC_DEV_NAME,
530 .owner = THIS_MODULE,
531 .pm = &pm8xxx_rtc_pm_ops,
532 },
533};
534
535module_platform_driver(pm8xxx_rtc_driver);
536
537MODULE_ALIAS("platform:rtc-pm8xxx");
538MODULE_DESCRIPTION("PMIC8xxx RTC driver");
539MODULE_LICENSE("GPL v2");
540MODULE_AUTHOR("Anirudh Ghayal <aghayal@codeaurora.org>");
1/* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
2 *
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License version 2 and
5 * only version 2 as published by the Free Software Foundation.
6 *
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
11 */
12#include <linux/of.h>
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/rtc.h>
16#include <linux/platform_device.h>
17#include <linux/pm.h>
18#include <linux/regmap.h>
19#include <linux/slab.h>
20#include <linux/spinlock.h>
21
22/* RTC Register offsets from RTC CTRL REG */
23#define PM8XXX_ALARM_CTRL_OFFSET 0x01
24#define PM8XXX_RTC_WRITE_OFFSET 0x02
25#define PM8XXX_RTC_READ_OFFSET 0x06
26#define PM8XXX_ALARM_RW_OFFSET 0x0A
27
28/* RTC_CTRL register bit fields */
29#define PM8xxx_RTC_ENABLE BIT(7)
30#define PM8xxx_RTC_ALARM_CLEAR BIT(0)
31
32#define NUM_8_BIT_RTC_REGS 0x4
33
34/**
35 * struct pm8xxx_rtc_regs - describe RTC registers per PMIC versions
36 * @ctrl: base address of control register
37 * @write: base address of write register
38 * @read: base address of read register
39 * @alarm_ctrl: base address of alarm control register
40 * @alarm_ctrl2: base address of alarm control2 register
41 * @alarm_rw: base address of alarm read-write register
42 * @alarm_en: alarm enable mask
43 */
44struct pm8xxx_rtc_regs {
45 unsigned int ctrl;
46 unsigned int write;
47 unsigned int read;
48 unsigned int alarm_ctrl;
49 unsigned int alarm_ctrl2;
50 unsigned int alarm_rw;
51 unsigned int alarm_en;
52};
53
54/**
55 * struct pm8xxx_rtc - rtc driver internal structure
56 * @rtc: rtc device for this driver.
57 * @regmap: regmap used to access RTC registers
58 * @allow_set_time: indicates whether writing to the RTC is allowed
59 * @rtc_alarm_irq: rtc alarm irq number.
60 * @ctrl_reg: rtc control register.
61 * @rtc_dev: device structure.
62 * @ctrl_reg_lock: spinlock protecting access to ctrl_reg.
63 */
64struct pm8xxx_rtc {
65 struct rtc_device *rtc;
66 struct regmap *regmap;
67 bool allow_set_time;
68 int rtc_alarm_irq;
69 const struct pm8xxx_rtc_regs *regs;
70 struct device *rtc_dev;
71 spinlock_t ctrl_reg_lock;
72};
73
74/*
75 * Steps to write the RTC registers.
76 * 1. Disable alarm if enabled.
77 * 2. Write 0x00 to LSB.
78 * 3. Write Byte[1], Byte[2], Byte[3] then Byte[0].
79 * 4. Enable alarm if disabled in step 1.
80 */
81static int pm8xxx_rtc_set_time(struct device *dev, struct rtc_time *tm)
82{
83 int rc, i;
84 unsigned long secs, irq_flags;
85 u8 value[NUM_8_BIT_RTC_REGS], alarm_enabled = 0;
86 unsigned int ctrl_reg;
87 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
88 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
89
90 if (!rtc_dd->allow_set_time)
91 return -EACCES;
92
93 rtc_tm_to_time(tm, &secs);
94
95 for (i = 0; i < NUM_8_BIT_RTC_REGS; i++) {
96 value[i] = secs & 0xFF;
97 secs >>= 8;
98 }
99
100 dev_dbg(dev, "Seconds value to be written to RTC = %lu\n", secs);
101
102 spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
103
104 rc = regmap_read(rtc_dd->regmap, regs->ctrl, &ctrl_reg);
105 if (rc)
106 goto rtc_rw_fail;
107
108 if (ctrl_reg & regs->alarm_en) {
109 alarm_enabled = 1;
110 ctrl_reg &= ~regs->alarm_en;
111 rc = regmap_write(rtc_dd->regmap, regs->ctrl, ctrl_reg);
112 if (rc) {
113 dev_err(dev, "Write to RTC control register failed\n");
114 goto rtc_rw_fail;
115 }
116 }
117
118 /* Write 0 to Byte[0] */
119 rc = regmap_write(rtc_dd->regmap, regs->write, 0);
120 if (rc) {
121 dev_err(dev, "Write to RTC write data register failed\n");
122 goto rtc_rw_fail;
123 }
124
125 /* Write Byte[1], Byte[2], Byte[3] */
126 rc = regmap_bulk_write(rtc_dd->regmap, regs->write + 1,
127 &value[1], sizeof(value) - 1);
128 if (rc) {
129 dev_err(dev, "Write to RTC write data register failed\n");
130 goto rtc_rw_fail;
131 }
132
133 /* Write Byte[0] */
134 rc = regmap_write(rtc_dd->regmap, regs->write, value[0]);
135 if (rc) {
136 dev_err(dev, "Write to RTC write data register failed\n");
137 goto rtc_rw_fail;
138 }
139
140 if (alarm_enabled) {
141 ctrl_reg |= regs->alarm_en;
142 rc = regmap_write(rtc_dd->regmap, regs->ctrl, ctrl_reg);
143 if (rc) {
144 dev_err(dev, "Write to RTC control register failed\n");
145 goto rtc_rw_fail;
146 }
147 }
148
149rtc_rw_fail:
150 spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
151
152 return rc;
153}
154
155static int pm8xxx_rtc_read_time(struct device *dev, struct rtc_time *tm)
156{
157 int rc;
158 u8 value[NUM_8_BIT_RTC_REGS];
159 unsigned long secs;
160 unsigned int reg;
161 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
162 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
163
164 rc = regmap_bulk_read(rtc_dd->regmap, regs->read, value, sizeof(value));
165 if (rc) {
166 dev_err(dev, "RTC read data register failed\n");
167 return rc;
168 }
169
170 /*
171 * Read the LSB again and check if there has been a carry over.
172 * If there is, redo the read operation.
173 */
174 rc = regmap_read(rtc_dd->regmap, regs->read, ®);
175 if (rc < 0) {
176 dev_err(dev, "RTC read data register failed\n");
177 return rc;
178 }
179
180 if (unlikely(reg < value[0])) {
181 rc = regmap_bulk_read(rtc_dd->regmap, regs->read,
182 value, sizeof(value));
183 if (rc) {
184 dev_err(dev, "RTC read data register failed\n");
185 return rc;
186 }
187 }
188
189 secs = value[0] | (value[1] << 8) | (value[2] << 16) | (value[3] << 24);
190
191 rtc_time_to_tm(secs, tm);
192
193 rc = rtc_valid_tm(tm);
194 if (rc < 0) {
195 dev_err(dev, "Invalid time read from RTC\n");
196 return rc;
197 }
198
199 dev_dbg(dev, "secs = %lu, h:m:s == %d:%d:%d, d/m/y = %d/%d/%d\n",
200 secs, tm->tm_hour, tm->tm_min, tm->tm_sec,
201 tm->tm_mday, tm->tm_mon, tm->tm_year);
202
203 return 0;
204}
205
206static int pm8xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
207{
208 int rc, i;
209 u8 value[NUM_8_BIT_RTC_REGS];
210 unsigned int ctrl_reg;
211 unsigned long secs, irq_flags;
212 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
213 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
214
215 rtc_tm_to_time(&alarm->time, &secs);
216
217 for (i = 0; i < NUM_8_BIT_RTC_REGS; i++) {
218 value[i] = secs & 0xFF;
219 secs >>= 8;
220 }
221
222 spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
223
224 rc = regmap_bulk_write(rtc_dd->regmap, regs->alarm_rw, value,
225 sizeof(value));
226 if (rc) {
227 dev_err(dev, "Write to RTC ALARM register failed\n");
228 goto rtc_rw_fail;
229 }
230
231 rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg);
232 if (rc)
233 goto rtc_rw_fail;
234
235 if (alarm->enabled)
236 ctrl_reg |= regs->alarm_en;
237 else
238 ctrl_reg &= ~regs->alarm_en;
239
240 rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl, ctrl_reg);
241 if (rc) {
242 dev_err(dev, "Write to RTC alarm control register failed\n");
243 goto rtc_rw_fail;
244 }
245
246 dev_dbg(dev, "Alarm Set for h:r:s=%d:%d:%d, d/m/y=%d/%d/%d\n",
247 alarm->time.tm_hour, alarm->time.tm_min,
248 alarm->time.tm_sec, alarm->time.tm_mday,
249 alarm->time.tm_mon, alarm->time.tm_year);
250rtc_rw_fail:
251 spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
252 return rc;
253}
254
255static int pm8xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
256{
257 int rc;
258 u8 value[NUM_8_BIT_RTC_REGS];
259 unsigned long secs;
260 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
261 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
262
263 rc = regmap_bulk_read(rtc_dd->regmap, regs->alarm_rw, value,
264 sizeof(value));
265 if (rc) {
266 dev_err(dev, "RTC alarm time read failed\n");
267 return rc;
268 }
269
270 secs = value[0] | (value[1] << 8) | (value[2] << 16) | (value[3] << 24);
271
272 rtc_time_to_tm(secs, &alarm->time);
273
274 rc = rtc_valid_tm(&alarm->time);
275 if (rc < 0) {
276 dev_err(dev, "Invalid alarm time read from RTC\n");
277 return rc;
278 }
279
280 dev_dbg(dev, "Alarm set for - h:r:s=%d:%d:%d, d/m/y=%d/%d/%d\n",
281 alarm->time.tm_hour, alarm->time.tm_min,
282 alarm->time.tm_sec, alarm->time.tm_mday,
283 alarm->time.tm_mon, alarm->time.tm_year);
284
285 return 0;
286}
287
288static int pm8xxx_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
289{
290 int rc;
291 unsigned long irq_flags;
292 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
293 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
294 unsigned int ctrl_reg;
295
296 spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
297
298 rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg);
299 if (rc)
300 goto rtc_rw_fail;
301
302 if (enable)
303 ctrl_reg |= regs->alarm_en;
304 else
305 ctrl_reg &= ~regs->alarm_en;
306
307 rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl, ctrl_reg);
308 if (rc) {
309 dev_err(dev, "Write to RTC control register failed\n");
310 goto rtc_rw_fail;
311 }
312
313rtc_rw_fail:
314 spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
315 return rc;
316}
317
318static const struct rtc_class_ops pm8xxx_rtc_ops = {
319 .read_time = pm8xxx_rtc_read_time,
320 .set_time = pm8xxx_rtc_set_time,
321 .set_alarm = pm8xxx_rtc_set_alarm,
322 .read_alarm = pm8xxx_rtc_read_alarm,
323 .alarm_irq_enable = pm8xxx_rtc_alarm_irq_enable,
324};
325
326static irqreturn_t pm8xxx_alarm_trigger(int irq, void *dev_id)
327{
328 struct pm8xxx_rtc *rtc_dd = dev_id;
329 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
330 unsigned int ctrl_reg;
331 int rc;
332 unsigned long irq_flags;
333
334 rtc_update_irq(rtc_dd->rtc, 1, RTC_IRQF | RTC_AF);
335
336 spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
337
338 /* Clear the alarm enable bit */
339 rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg);
340 if (rc) {
341 spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
342 goto rtc_alarm_handled;
343 }
344
345 ctrl_reg &= ~regs->alarm_en;
346
347 rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl, ctrl_reg);
348 if (rc) {
349 spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
350 dev_err(rtc_dd->rtc_dev,
351 "Write to alarm control register failed\n");
352 goto rtc_alarm_handled;
353 }
354
355 spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
356
357 /* Clear RTC alarm register */
358 rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl2, &ctrl_reg);
359 if (rc) {
360 dev_err(rtc_dd->rtc_dev,
361 "RTC Alarm control2 register read failed\n");
362 goto rtc_alarm_handled;
363 }
364
365 ctrl_reg |= PM8xxx_RTC_ALARM_CLEAR;
366 rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl2, ctrl_reg);
367 if (rc)
368 dev_err(rtc_dd->rtc_dev,
369 "Write to RTC Alarm control2 register failed\n");
370
371rtc_alarm_handled:
372 return IRQ_HANDLED;
373}
374
375static int pm8xxx_rtc_enable(struct pm8xxx_rtc *rtc_dd)
376{
377 const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
378 unsigned int ctrl_reg;
379 int rc;
380
381 /* Check if the RTC is on, else turn it on */
382 rc = regmap_read(rtc_dd->regmap, regs->ctrl, &ctrl_reg);
383 if (rc)
384 return rc;
385
386 if (!(ctrl_reg & PM8xxx_RTC_ENABLE)) {
387 ctrl_reg |= PM8xxx_RTC_ENABLE;
388 rc = regmap_write(rtc_dd->regmap, regs->ctrl, ctrl_reg);
389 if (rc)
390 return rc;
391 }
392
393 return 0;
394}
395
396static const struct pm8xxx_rtc_regs pm8921_regs = {
397 .ctrl = 0x11d,
398 .write = 0x11f,
399 .read = 0x123,
400 .alarm_rw = 0x127,
401 .alarm_ctrl = 0x11d,
402 .alarm_ctrl2 = 0x11e,
403 .alarm_en = BIT(1),
404};
405
406static const struct pm8xxx_rtc_regs pm8058_regs = {
407 .ctrl = 0x1e8,
408 .write = 0x1ea,
409 .read = 0x1ee,
410 .alarm_rw = 0x1f2,
411 .alarm_ctrl = 0x1e8,
412 .alarm_ctrl2 = 0x1e9,
413 .alarm_en = BIT(1),
414};
415
416static const struct pm8xxx_rtc_regs pm8941_regs = {
417 .ctrl = 0x6046,
418 .write = 0x6040,
419 .read = 0x6048,
420 .alarm_rw = 0x6140,
421 .alarm_ctrl = 0x6146,
422 .alarm_ctrl2 = 0x6148,
423 .alarm_en = BIT(7),
424};
425
426/*
427 * Hardcoded RTC bases until IORESOURCE_REG mapping is figured out
428 */
429static const struct of_device_id pm8xxx_id_table[] = {
430 { .compatible = "qcom,pm8921-rtc", .data = &pm8921_regs },
431 { .compatible = "qcom,pm8018-rtc", .data = &pm8921_regs },
432 { .compatible = "qcom,pm8058-rtc", .data = &pm8058_regs },
433 { .compatible = "qcom,pm8941-rtc", .data = &pm8941_regs },
434 { },
435};
436MODULE_DEVICE_TABLE(of, pm8xxx_id_table);
437
438static int pm8xxx_rtc_probe(struct platform_device *pdev)
439{
440 int rc;
441 struct pm8xxx_rtc *rtc_dd;
442 const struct of_device_id *match;
443
444 match = of_match_node(pm8xxx_id_table, pdev->dev.of_node);
445 if (!match)
446 return -ENXIO;
447
448 rtc_dd = devm_kzalloc(&pdev->dev, sizeof(*rtc_dd), GFP_KERNEL);
449 if (rtc_dd == NULL)
450 return -ENOMEM;
451
452 /* Initialise spinlock to protect RTC control register */
453 spin_lock_init(&rtc_dd->ctrl_reg_lock);
454
455 rtc_dd->regmap = dev_get_regmap(pdev->dev.parent, NULL);
456 if (!rtc_dd->regmap) {
457 dev_err(&pdev->dev, "Parent regmap unavailable.\n");
458 return -ENXIO;
459 }
460
461 rtc_dd->rtc_alarm_irq = platform_get_irq(pdev, 0);
462 if (rtc_dd->rtc_alarm_irq < 0) {
463 dev_err(&pdev->dev, "Alarm IRQ resource absent!\n");
464 return -ENXIO;
465 }
466
467 rtc_dd->allow_set_time = of_property_read_bool(pdev->dev.of_node,
468 "allow-set-time");
469
470 rtc_dd->regs = match->data;
471 rtc_dd->rtc_dev = &pdev->dev;
472
473 rc = pm8xxx_rtc_enable(rtc_dd);
474 if (rc)
475 return rc;
476
477 platform_set_drvdata(pdev, rtc_dd);
478
479 device_init_wakeup(&pdev->dev, 1);
480
481 /* Register the RTC device */
482 rtc_dd->rtc = devm_rtc_device_register(&pdev->dev, "pm8xxx_rtc",
483 &pm8xxx_rtc_ops, THIS_MODULE);
484 if (IS_ERR(rtc_dd->rtc)) {
485 dev_err(&pdev->dev, "%s: RTC registration failed (%ld)\n",
486 __func__, PTR_ERR(rtc_dd->rtc));
487 return PTR_ERR(rtc_dd->rtc);
488 }
489
490 /* Request the alarm IRQ */
491 rc = devm_request_any_context_irq(&pdev->dev, rtc_dd->rtc_alarm_irq,
492 pm8xxx_alarm_trigger,
493 IRQF_TRIGGER_RISING,
494 "pm8xxx_rtc_alarm", rtc_dd);
495 if (rc < 0) {
496 dev_err(&pdev->dev, "Request IRQ failed (%d)\n", rc);
497 return rc;
498 }
499
500 dev_dbg(&pdev->dev, "Probe success !!\n");
501
502 return 0;
503}
504
505#ifdef CONFIG_PM_SLEEP
506static int pm8xxx_rtc_resume(struct device *dev)
507{
508 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
509
510 if (device_may_wakeup(dev))
511 disable_irq_wake(rtc_dd->rtc_alarm_irq);
512
513 return 0;
514}
515
516static int pm8xxx_rtc_suspend(struct device *dev)
517{
518 struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
519
520 if (device_may_wakeup(dev))
521 enable_irq_wake(rtc_dd->rtc_alarm_irq);
522
523 return 0;
524}
525#endif
526
527static SIMPLE_DEV_PM_OPS(pm8xxx_rtc_pm_ops,
528 pm8xxx_rtc_suspend,
529 pm8xxx_rtc_resume);
530
531static struct platform_driver pm8xxx_rtc_driver = {
532 .probe = pm8xxx_rtc_probe,
533 .driver = {
534 .name = "rtc-pm8xxx",
535 .pm = &pm8xxx_rtc_pm_ops,
536 .of_match_table = pm8xxx_id_table,
537 },
538};
539
540module_platform_driver(pm8xxx_rtc_driver);
541
542MODULE_ALIAS("platform:rtc-pm8xxx");
543MODULE_DESCRIPTION("PMIC8xxx RTC driver");
544MODULE_LICENSE("GPL v2");
545MODULE_AUTHOR("Anirudh Ghayal <aghayal@codeaurora.org>");