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1/*
2 * rtc-mrst.c: Driver for Moorestown virtual RTC
3 *
4 * (C) Copyright 2009 Intel Corporation
5 * Author: Jacob Pan (jacob.jun.pan@intel.com)
6 * Feng Tang (feng.tang@intel.com)
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; version 2
11 * of the License.
12 *
13 * Note:
14 * VRTC is emulated by system controller firmware, the real HW
15 * RTC is located in the PMIC device. SCU FW shadows PMIC RTC
16 * in a memory mapped IO space that is visible to the host IA
17 * processor.
18 *
19 * This driver is based upon drivers/rtc/rtc-cmos.c
20 */
21
22/*
23 * Note:
24 * * vRTC only supports binary mode and 24H mode
25 * * vRTC only support PIE and AIE, no UIE, and its PIE only happens
26 * at 23:59:59pm everyday, no support for adjustable frequency
27 * * Alarm function is also limited to hr/min/sec.
28 */
29
30#include <linux/mod_devicetable.h>
31#include <linux/platform_device.h>
32#include <linux/interrupt.h>
33#include <linux/spinlock.h>
34#include <linux/kernel.h>
35#include <linux/module.h>
36#include <linux/init.h>
37#include <linux/sfi.h>
38
39#include <asm-generic/rtc.h>
40#include <asm/intel_scu_ipc.h>
41#include <asm/mrst.h>
42#include <asm/mrst-vrtc.h>
43
44struct mrst_rtc {
45 struct rtc_device *rtc;
46 struct device *dev;
47 int irq;
48 struct resource *iomem;
49
50 u8 enabled_wake;
51 u8 suspend_ctrl;
52};
53
54static const char driver_name[] = "rtc_mrst";
55
56#define RTC_IRQMASK (RTC_PF | RTC_AF)
57
58static inline int is_intr(u8 rtc_intr)
59{
60 if (!(rtc_intr & RTC_IRQF))
61 return 0;
62 return rtc_intr & RTC_IRQMASK;
63}
64
65static inline unsigned char vrtc_is_updating(void)
66{
67 unsigned char uip;
68 unsigned long flags;
69
70 spin_lock_irqsave(&rtc_lock, flags);
71 uip = (vrtc_cmos_read(RTC_FREQ_SELECT) & RTC_UIP);
72 spin_unlock_irqrestore(&rtc_lock, flags);
73 return uip;
74}
75
76/*
77 * rtc_time's year contains the increment over 1900, but vRTC's YEAR
78 * register can't be programmed to value larger than 0x64, so vRTC
79 * driver chose to use 1960 (1970 is UNIX time start point) as the base,
80 * and does the translation at read/write time.
81 *
82 * Why not just use 1970 as the offset? it's because using 1960 will
83 * make it consistent in leap year setting for both vrtc and low-level
84 * physical rtc devices.
85 */
86static int mrst_read_time(struct device *dev, struct rtc_time *time)
87{
88 unsigned long flags;
89
90 if (vrtc_is_updating())
91 mdelay(20);
92
93 spin_lock_irqsave(&rtc_lock, flags);
94 time->tm_sec = vrtc_cmos_read(RTC_SECONDS);
95 time->tm_min = vrtc_cmos_read(RTC_MINUTES);
96 time->tm_hour = vrtc_cmos_read(RTC_HOURS);
97 time->tm_mday = vrtc_cmos_read(RTC_DAY_OF_MONTH);
98 time->tm_mon = vrtc_cmos_read(RTC_MONTH);
99 time->tm_year = vrtc_cmos_read(RTC_YEAR);
100 spin_unlock_irqrestore(&rtc_lock, flags);
101
102 /* Adjust for the 1960/1900 */
103 time->tm_year += 60;
104 time->tm_mon--;
105 return RTC_24H;
106}
107
108static int mrst_set_time(struct device *dev, struct rtc_time *time)
109{
110 int ret;
111 unsigned long flags;
112 unsigned char mon, day, hrs, min, sec;
113 unsigned int yrs;
114
115 yrs = time->tm_year;
116 mon = time->tm_mon + 1; /* tm_mon starts at zero */
117 day = time->tm_mday;
118 hrs = time->tm_hour;
119 min = time->tm_min;
120 sec = time->tm_sec;
121
122 if (yrs < 70 || yrs > 138)
123 return -EINVAL;
124 yrs -= 60;
125
126 spin_lock_irqsave(&rtc_lock, flags);
127
128 vrtc_cmos_write(yrs, RTC_YEAR);
129 vrtc_cmos_write(mon, RTC_MONTH);
130 vrtc_cmos_write(day, RTC_DAY_OF_MONTH);
131 vrtc_cmos_write(hrs, RTC_HOURS);
132 vrtc_cmos_write(min, RTC_MINUTES);
133 vrtc_cmos_write(sec, RTC_SECONDS);
134
135 spin_unlock_irqrestore(&rtc_lock, flags);
136
137 ret = intel_scu_ipc_simple_command(IPCMSG_VRTC, IPC_CMD_VRTC_SETTIME);
138 return ret;
139}
140
141static int mrst_read_alarm(struct device *dev, struct rtc_wkalrm *t)
142{
143 struct mrst_rtc *mrst = dev_get_drvdata(dev);
144 unsigned char rtc_control;
145
146 if (mrst->irq <= 0)
147 return -EIO;
148
149 /* Basic alarms only support hour, minute, and seconds fields.
150 * Some also support day and month, for alarms up to a year in
151 * the future.
152 */
153 t->time.tm_mday = -1;
154 t->time.tm_mon = -1;
155 t->time.tm_year = -1;
156
157 /* vRTC only supports binary mode */
158 spin_lock_irq(&rtc_lock);
159 t->time.tm_sec = vrtc_cmos_read(RTC_SECONDS_ALARM);
160 t->time.tm_min = vrtc_cmos_read(RTC_MINUTES_ALARM);
161 t->time.tm_hour = vrtc_cmos_read(RTC_HOURS_ALARM);
162
163 rtc_control = vrtc_cmos_read(RTC_CONTROL);
164 spin_unlock_irq(&rtc_lock);
165
166 t->enabled = !!(rtc_control & RTC_AIE);
167 t->pending = 0;
168
169 return 0;
170}
171
172static void mrst_checkintr(struct mrst_rtc *mrst, unsigned char rtc_control)
173{
174 unsigned char rtc_intr;
175
176 /*
177 * NOTE after changing RTC_xIE bits we always read INTR_FLAGS;
178 * allegedly some older rtcs need that to handle irqs properly
179 */
180 rtc_intr = vrtc_cmos_read(RTC_INTR_FLAGS);
181 rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
182 if (is_intr(rtc_intr))
183 rtc_update_irq(mrst->rtc, 1, rtc_intr);
184}
185
186static void mrst_irq_enable(struct mrst_rtc *mrst, unsigned char mask)
187{
188 unsigned char rtc_control;
189
190 /*
191 * Flush any pending IRQ status, notably for update irqs,
192 * before we enable new IRQs
193 */
194 rtc_control = vrtc_cmos_read(RTC_CONTROL);
195 mrst_checkintr(mrst, rtc_control);
196
197 rtc_control |= mask;
198 vrtc_cmos_write(rtc_control, RTC_CONTROL);
199
200 mrst_checkintr(mrst, rtc_control);
201}
202
203static void mrst_irq_disable(struct mrst_rtc *mrst, unsigned char mask)
204{
205 unsigned char rtc_control;
206
207 rtc_control = vrtc_cmos_read(RTC_CONTROL);
208 rtc_control &= ~mask;
209 vrtc_cmos_write(rtc_control, RTC_CONTROL);
210 mrst_checkintr(mrst, rtc_control);
211}
212
213static int mrst_set_alarm(struct device *dev, struct rtc_wkalrm *t)
214{
215 struct mrst_rtc *mrst = dev_get_drvdata(dev);
216 unsigned char hrs, min, sec;
217 int ret = 0;
218
219 if (!mrst->irq)
220 return -EIO;
221
222 hrs = t->time.tm_hour;
223 min = t->time.tm_min;
224 sec = t->time.tm_sec;
225
226 spin_lock_irq(&rtc_lock);
227 /* Next rtc irq must not be from previous alarm setting */
228 mrst_irq_disable(mrst, RTC_AIE);
229
230 /* Update alarm */
231 vrtc_cmos_write(hrs, RTC_HOURS_ALARM);
232 vrtc_cmos_write(min, RTC_MINUTES_ALARM);
233 vrtc_cmos_write(sec, RTC_SECONDS_ALARM);
234
235 spin_unlock_irq(&rtc_lock);
236
237 ret = intel_scu_ipc_simple_command(IPCMSG_VRTC, IPC_CMD_VRTC_SETALARM);
238 if (ret)
239 return ret;
240
241 spin_lock_irq(&rtc_lock);
242 if (t->enabled)
243 mrst_irq_enable(mrst, RTC_AIE);
244
245 spin_unlock_irq(&rtc_lock);
246
247 return 0;
248}
249
250/* Currently, the vRTC doesn't support UIE ON/OFF */
251static int mrst_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
252{
253 struct mrst_rtc *mrst = dev_get_drvdata(dev);
254 unsigned long flags;
255
256 spin_lock_irqsave(&rtc_lock, flags);
257 if (enabled)
258 mrst_irq_enable(mrst, RTC_AIE);
259 else
260 mrst_irq_disable(mrst, RTC_AIE);
261 spin_unlock_irqrestore(&rtc_lock, flags);
262 return 0;
263}
264
265
266#if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
267
268static int mrst_procfs(struct device *dev, struct seq_file *seq)
269{
270 unsigned char rtc_control, valid;
271
272 spin_lock_irq(&rtc_lock);
273 rtc_control = vrtc_cmos_read(RTC_CONTROL);
274 valid = vrtc_cmos_read(RTC_VALID);
275 spin_unlock_irq(&rtc_lock);
276
277 return seq_printf(seq,
278 "periodic_IRQ\t: %s\n"
279 "alarm\t\t: %s\n"
280 "BCD\t\t: no\n"
281 "periodic_freq\t: daily (not adjustable)\n",
282 (rtc_control & RTC_PIE) ? "on" : "off",
283 (rtc_control & RTC_AIE) ? "on" : "off");
284}
285
286#else
287#define mrst_procfs NULL
288#endif
289
290static const struct rtc_class_ops mrst_rtc_ops = {
291 .read_time = mrst_read_time,
292 .set_time = mrst_set_time,
293 .read_alarm = mrst_read_alarm,
294 .set_alarm = mrst_set_alarm,
295 .proc = mrst_procfs,
296 .alarm_irq_enable = mrst_rtc_alarm_irq_enable,
297};
298
299static struct mrst_rtc mrst_rtc;
300
301/*
302 * When vRTC IRQ is captured by SCU FW, FW will clear the AIE bit in
303 * Reg B, so no need for this driver to clear it
304 */
305static irqreturn_t mrst_rtc_irq(int irq, void *p)
306{
307 u8 irqstat;
308
309 spin_lock(&rtc_lock);
310 /* This read will clear all IRQ flags inside Reg C */
311 irqstat = vrtc_cmos_read(RTC_INTR_FLAGS);
312 spin_unlock(&rtc_lock);
313
314 irqstat &= RTC_IRQMASK | RTC_IRQF;
315 if (is_intr(irqstat)) {
316 rtc_update_irq(p, 1, irqstat);
317 return IRQ_HANDLED;
318 }
319 return IRQ_NONE;
320}
321
322static int __devinit
323vrtc_mrst_do_probe(struct device *dev, struct resource *iomem, int rtc_irq)
324{
325 int retval = 0;
326 unsigned char rtc_control;
327
328 /* There can be only one ... */
329 if (mrst_rtc.dev)
330 return -EBUSY;
331
332 if (!iomem)
333 return -ENODEV;
334
335 iomem = request_mem_region(iomem->start, resource_size(iomem),
336 driver_name);
337 if (!iomem) {
338 dev_dbg(dev, "i/o mem already in use.\n");
339 return -EBUSY;
340 }
341
342 mrst_rtc.irq = rtc_irq;
343 mrst_rtc.iomem = iomem;
344 mrst_rtc.dev = dev;
345 dev_set_drvdata(dev, &mrst_rtc);
346
347 mrst_rtc.rtc = rtc_device_register(driver_name, dev,
348 &mrst_rtc_ops, THIS_MODULE);
349 if (IS_ERR(mrst_rtc.rtc)) {
350 retval = PTR_ERR(mrst_rtc.rtc);
351 goto cleanup0;
352 }
353
354 rename_region(iomem, dev_name(&mrst_rtc.rtc->dev));
355
356 spin_lock_irq(&rtc_lock);
357 mrst_irq_disable(&mrst_rtc, RTC_PIE | RTC_AIE);
358 rtc_control = vrtc_cmos_read(RTC_CONTROL);
359 spin_unlock_irq(&rtc_lock);
360
361 if (!(rtc_control & RTC_24H) || (rtc_control & (RTC_DM_BINARY)))
362 dev_dbg(dev, "TODO: support more than 24-hr BCD mode\n");
363
364 if (rtc_irq) {
365 retval = request_irq(rtc_irq, mrst_rtc_irq,
366 IRQF_DISABLED, dev_name(&mrst_rtc.rtc->dev),
367 mrst_rtc.rtc);
368 if (retval < 0) {
369 dev_dbg(dev, "IRQ %d is already in use, err %d\n",
370 rtc_irq, retval);
371 goto cleanup1;
372 }
373 }
374 dev_dbg(dev, "initialised\n");
375 return 0;
376
377cleanup1:
378 rtc_device_unregister(mrst_rtc.rtc);
379cleanup0:
380 dev_set_drvdata(dev, NULL);
381 mrst_rtc.dev = NULL;
382 release_mem_region(iomem->start, resource_size(iomem));
383 dev_err(dev, "rtc-mrst: unable to initialise\n");
384 return retval;
385}
386
387static void rtc_mrst_do_shutdown(void)
388{
389 spin_lock_irq(&rtc_lock);
390 mrst_irq_disable(&mrst_rtc, RTC_IRQMASK);
391 spin_unlock_irq(&rtc_lock);
392}
393
394static void __devexit rtc_mrst_do_remove(struct device *dev)
395{
396 struct mrst_rtc *mrst = dev_get_drvdata(dev);
397 struct resource *iomem;
398
399 rtc_mrst_do_shutdown();
400
401 if (mrst->irq)
402 free_irq(mrst->irq, mrst->rtc);
403
404 rtc_device_unregister(mrst->rtc);
405 mrst->rtc = NULL;
406
407 iomem = mrst->iomem;
408 release_mem_region(iomem->start, resource_size(iomem));
409 mrst->iomem = NULL;
410
411 mrst->dev = NULL;
412 dev_set_drvdata(dev, NULL);
413}
414
415#ifdef CONFIG_PM
416static int mrst_suspend(struct device *dev, pm_message_t mesg)
417{
418 struct mrst_rtc *mrst = dev_get_drvdata(dev);
419 unsigned char tmp;
420
421 /* Only the alarm might be a wakeup event source */
422 spin_lock_irq(&rtc_lock);
423 mrst->suspend_ctrl = tmp = vrtc_cmos_read(RTC_CONTROL);
424 if (tmp & (RTC_PIE | RTC_AIE)) {
425 unsigned char mask;
426
427 if (device_may_wakeup(dev))
428 mask = RTC_IRQMASK & ~RTC_AIE;
429 else
430 mask = RTC_IRQMASK;
431 tmp &= ~mask;
432 vrtc_cmos_write(tmp, RTC_CONTROL);
433
434 mrst_checkintr(mrst, tmp);
435 }
436 spin_unlock_irq(&rtc_lock);
437
438 if (tmp & RTC_AIE) {
439 mrst->enabled_wake = 1;
440 enable_irq_wake(mrst->irq);
441 }
442
443 dev_dbg(&mrst_rtc.rtc->dev, "suspend%s, ctrl %02x\n",
444 (tmp & RTC_AIE) ? ", alarm may wake" : "",
445 tmp);
446
447 return 0;
448}
449
450/*
451 * We want RTC alarms to wake us from the deep power saving state
452 */
453static inline int mrst_poweroff(struct device *dev)
454{
455 return mrst_suspend(dev, PMSG_HIBERNATE);
456}
457
458static int mrst_resume(struct device *dev)
459{
460 struct mrst_rtc *mrst = dev_get_drvdata(dev);
461 unsigned char tmp = mrst->suspend_ctrl;
462
463 /* Re-enable any irqs previously active */
464 if (tmp & RTC_IRQMASK) {
465 unsigned char mask;
466
467 if (mrst->enabled_wake) {
468 disable_irq_wake(mrst->irq);
469 mrst->enabled_wake = 0;
470 }
471
472 spin_lock_irq(&rtc_lock);
473 do {
474 vrtc_cmos_write(tmp, RTC_CONTROL);
475
476 mask = vrtc_cmos_read(RTC_INTR_FLAGS);
477 mask &= (tmp & RTC_IRQMASK) | RTC_IRQF;
478 if (!is_intr(mask))
479 break;
480
481 rtc_update_irq(mrst->rtc, 1, mask);
482 tmp &= ~RTC_AIE;
483 } while (mask & RTC_AIE);
484 spin_unlock_irq(&rtc_lock);
485 }
486
487 dev_dbg(&mrst_rtc.rtc->dev, "resume, ctrl %02x\n", tmp);
488
489 return 0;
490}
491
492#else
493#define mrst_suspend NULL
494#define mrst_resume NULL
495
496static inline int mrst_poweroff(struct device *dev)
497{
498 return -ENOSYS;
499}
500
501#endif
502
503static int __devinit vrtc_mrst_platform_probe(struct platform_device *pdev)
504{
505 return vrtc_mrst_do_probe(&pdev->dev,
506 platform_get_resource(pdev, IORESOURCE_MEM, 0),
507 platform_get_irq(pdev, 0));
508}
509
510static int __devexit vrtc_mrst_platform_remove(struct platform_device *pdev)
511{
512 rtc_mrst_do_remove(&pdev->dev);
513 return 0;
514}
515
516static void vrtc_mrst_platform_shutdown(struct platform_device *pdev)
517{
518 if (system_state == SYSTEM_POWER_OFF && !mrst_poweroff(&pdev->dev))
519 return;
520
521 rtc_mrst_do_shutdown();
522}
523
524MODULE_ALIAS("platform:vrtc_mrst");
525
526static struct platform_driver vrtc_mrst_platform_driver = {
527 .probe = vrtc_mrst_platform_probe,
528 .remove = __devexit_p(vrtc_mrst_platform_remove),
529 .shutdown = vrtc_mrst_platform_shutdown,
530 .driver = {
531 .name = (char *) driver_name,
532 .suspend = mrst_suspend,
533 .resume = mrst_resume,
534 }
535};
536
537static int __init vrtc_mrst_init(void)
538{
539 return platform_driver_register(&vrtc_mrst_platform_driver);
540}
541
542static void __exit vrtc_mrst_exit(void)
543{
544 platform_driver_unregister(&vrtc_mrst_platform_driver);
545}
546
547module_init(vrtc_mrst_init);
548module_exit(vrtc_mrst_exit);
549
550MODULE_AUTHOR("Jacob Pan; Feng Tang");
551MODULE_DESCRIPTION("Driver for Moorestown virtual RTC");
552MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * rtc-mrst.c: Driver for Moorestown virtual RTC
4 *
5 * (C) Copyright 2009 Intel Corporation
6 * Author: Jacob Pan (jacob.jun.pan@intel.com)
7 * Feng Tang (feng.tang@intel.com)
8 *
9 * Note:
10 * VRTC is emulated by system controller firmware, the real HW
11 * RTC is located in the PMIC device. SCU FW shadows PMIC RTC
12 * in a memory mapped IO space that is visible to the host IA
13 * processor.
14 *
15 * This driver is based upon drivers/rtc/rtc-cmos.c
16 */
17
18/*
19 * Note:
20 * * vRTC only supports binary mode and 24H mode
21 * * vRTC only support PIE and AIE, no UIE, and its PIE only happens
22 * at 23:59:59pm everyday, no support for adjustable frequency
23 * * Alarm function is also limited to hr/min/sec.
24 */
25
26#include <linux/mod_devicetable.h>
27#include <linux/platform_device.h>
28#include <linux/interrupt.h>
29#include <linux/spinlock.h>
30#include <linux/kernel.h>
31#include <linux/mc146818rtc.h>
32#include <linux/module.h>
33#include <linux/init.h>
34#include <linux/sfi.h>
35
36#include <asm/intel_scu_ipc.h>
37#include <asm/intel-mid.h>
38#include <asm/intel_mid_vrtc.h>
39
40struct mrst_rtc {
41 struct rtc_device *rtc;
42 struct device *dev;
43 int irq;
44
45 u8 enabled_wake;
46 u8 suspend_ctrl;
47};
48
49static const char driver_name[] = "rtc_mrst";
50
51#define RTC_IRQMASK (RTC_PF | RTC_AF)
52
53static inline int is_intr(u8 rtc_intr)
54{
55 if (!(rtc_intr & RTC_IRQF))
56 return 0;
57 return rtc_intr & RTC_IRQMASK;
58}
59
60static inline unsigned char vrtc_is_updating(void)
61{
62 unsigned char uip;
63 unsigned long flags;
64
65 spin_lock_irqsave(&rtc_lock, flags);
66 uip = (vrtc_cmos_read(RTC_FREQ_SELECT) & RTC_UIP);
67 spin_unlock_irqrestore(&rtc_lock, flags);
68 return uip;
69}
70
71/*
72 * rtc_time's year contains the increment over 1900, but vRTC's YEAR
73 * register can't be programmed to value larger than 0x64, so vRTC
74 * driver chose to use 1972 (1970 is UNIX time start point) as the base,
75 * and does the translation at read/write time.
76 *
77 * Why not just use 1970 as the offset? it's because using 1972 will
78 * make it consistent in leap year setting for both vrtc and low-level
79 * physical rtc devices. Then why not use 1960 as the offset? If we use
80 * 1960, for a device's first use, its YEAR register is 0 and the system
81 * year will be parsed as 1960 which is not a valid UNIX time and will
82 * cause many applications to fail mysteriously.
83 */
84static int mrst_read_time(struct device *dev, struct rtc_time *time)
85{
86 unsigned long flags;
87
88 if (vrtc_is_updating())
89 msleep(20);
90
91 spin_lock_irqsave(&rtc_lock, flags);
92 time->tm_sec = vrtc_cmos_read(RTC_SECONDS);
93 time->tm_min = vrtc_cmos_read(RTC_MINUTES);
94 time->tm_hour = vrtc_cmos_read(RTC_HOURS);
95 time->tm_mday = vrtc_cmos_read(RTC_DAY_OF_MONTH);
96 time->tm_mon = vrtc_cmos_read(RTC_MONTH);
97 time->tm_year = vrtc_cmos_read(RTC_YEAR);
98 spin_unlock_irqrestore(&rtc_lock, flags);
99
100 /* Adjust for the 1972/1900 */
101 time->tm_year += 72;
102 time->tm_mon--;
103 return 0;
104}
105
106static int mrst_set_time(struct device *dev, struct rtc_time *time)
107{
108 int ret;
109 unsigned long flags;
110 unsigned char mon, day, hrs, min, sec;
111 unsigned int yrs;
112
113 yrs = time->tm_year;
114 mon = time->tm_mon + 1; /* tm_mon starts at zero */
115 day = time->tm_mday;
116 hrs = time->tm_hour;
117 min = time->tm_min;
118 sec = time->tm_sec;
119
120 if (yrs < 72 || yrs > 172)
121 return -EINVAL;
122 yrs -= 72;
123
124 spin_lock_irqsave(&rtc_lock, flags);
125
126 vrtc_cmos_write(yrs, RTC_YEAR);
127 vrtc_cmos_write(mon, RTC_MONTH);
128 vrtc_cmos_write(day, RTC_DAY_OF_MONTH);
129 vrtc_cmos_write(hrs, RTC_HOURS);
130 vrtc_cmos_write(min, RTC_MINUTES);
131 vrtc_cmos_write(sec, RTC_SECONDS);
132
133 spin_unlock_irqrestore(&rtc_lock, flags);
134
135 ret = intel_scu_ipc_simple_command(IPCMSG_VRTC, IPC_CMD_VRTC_SETTIME);
136 return ret;
137}
138
139static int mrst_read_alarm(struct device *dev, struct rtc_wkalrm *t)
140{
141 struct mrst_rtc *mrst = dev_get_drvdata(dev);
142 unsigned char rtc_control;
143
144 if (mrst->irq <= 0)
145 return -EIO;
146
147 /* vRTC only supports binary mode */
148 spin_lock_irq(&rtc_lock);
149 t->time.tm_sec = vrtc_cmos_read(RTC_SECONDS_ALARM);
150 t->time.tm_min = vrtc_cmos_read(RTC_MINUTES_ALARM);
151 t->time.tm_hour = vrtc_cmos_read(RTC_HOURS_ALARM);
152
153 rtc_control = vrtc_cmos_read(RTC_CONTROL);
154 spin_unlock_irq(&rtc_lock);
155
156 t->enabled = !!(rtc_control & RTC_AIE);
157 t->pending = 0;
158
159 return 0;
160}
161
162static void mrst_checkintr(struct mrst_rtc *mrst, unsigned char rtc_control)
163{
164 unsigned char rtc_intr;
165
166 /*
167 * NOTE after changing RTC_xIE bits we always read INTR_FLAGS;
168 * allegedly some older rtcs need that to handle irqs properly
169 */
170 rtc_intr = vrtc_cmos_read(RTC_INTR_FLAGS);
171 rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
172 if (is_intr(rtc_intr))
173 rtc_update_irq(mrst->rtc, 1, rtc_intr);
174}
175
176static void mrst_irq_enable(struct mrst_rtc *mrst, unsigned char mask)
177{
178 unsigned char rtc_control;
179
180 /*
181 * Flush any pending IRQ status, notably for update irqs,
182 * before we enable new IRQs
183 */
184 rtc_control = vrtc_cmos_read(RTC_CONTROL);
185 mrst_checkintr(mrst, rtc_control);
186
187 rtc_control |= mask;
188 vrtc_cmos_write(rtc_control, RTC_CONTROL);
189
190 mrst_checkintr(mrst, rtc_control);
191}
192
193static void mrst_irq_disable(struct mrst_rtc *mrst, unsigned char mask)
194{
195 unsigned char rtc_control;
196
197 rtc_control = vrtc_cmos_read(RTC_CONTROL);
198 rtc_control &= ~mask;
199 vrtc_cmos_write(rtc_control, RTC_CONTROL);
200 mrst_checkintr(mrst, rtc_control);
201}
202
203static int mrst_set_alarm(struct device *dev, struct rtc_wkalrm *t)
204{
205 struct mrst_rtc *mrst = dev_get_drvdata(dev);
206 unsigned char hrs, min, sec;
207 int ret = 0;
208
209 if (!mrst->irq)
210 return -EIO;
211
212 hrs = t->time.tm_hour;
213 min = t->time.tm_min;
214 sec = t->time.tm_sec;
215
216 spin_lock_irq(&rtc_lock);
217 /* Next rtc irq must not be from previous alarm setting */
218 mrst_irq_disable(mrst, RTC_AIE);
219
220 /* Update alarm */
221 vrtc_cmos_write(hrs, RTC_HOURS_ALARM);
222 vrtc_cmos_write(min, RTC_MINUTES_ALARM);
223 vrtc_cmos_write(sec, RTC_SECONDS_ALARM);
224
225 spin_unlock_irq(&rtc_lock);
226
227 ret = intel_scu_ipc_simple_command(IPCMSG_VRTC, IPC_CMD_VRTC_SETALARM);
228 if (ret)
229 return ret;
230
231 spin_lock_irq(&rtc_lock);
232 if (t->enabled)
233 mrst_irq_enable(mrst, RTC_AIE);
234
235 spin_unlock_irq(&rtc_lock);
236
237 return 0;
238}
239
240/* Currently, the vRTC doesn't support UIE ON/OFF */
241static int mrst_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
242{
243 struct mrst_rtc *mrst = dev_get_drvdata(dev);
244 unsigned long flags;
245
246 spin_lock_irqsave(&rtc_lock, flags);
247 if (enabled)
248 mrst_irq_enable(mrst, RTC_AIE);
249 else
250 mrst_irq_disable(mrst, RTC_AIE);
251 spin_unlock_irqrestore(&rtc_lock, flags);
252 return 0;
253}
254
255
256#if IS_ENABLED(CONFIG_RTC_INTF_PROC)
257
258static int mrst_procfs(struct device *dev, struct seq_file *seq)
259{
260 unsigned char rtc_control;
261
262 spin_lock_irq(&rtc_lock);
263 rtc_control = vrtc_cmos_read(RTC_CONTROL);
264 spin_unlock_irq(&rtc_lock);
265
266 seq_printf(seq,
267 "periodic_IRQ\t: %s\n"
268 "alarm\t\t: %s\n"
269 "BCD\t\t: no\n"
270 "periodic_freq\t: daily (not adjustable)\n",
271 (rtc_control & RTC_PIE) ? "on" : "off",
272 (rtc_control & RTC_AIE) ? "on" : "off");
273
274 return 0;
275}
276
277#else
278#define mrst_procfs NULL
279#endif
280
281static const struct rtc_class_ops mrst_rtc_ops = {
282 .read_time = mrst_read_time,
283 .set_time = mrst_set_time,
284 .read_alarm = mrst_read_alarm,
285 .set_alarm = mrst_set_alarm,
286 .proc = mrst_procfs,
287 .alarm_irq_enable = mrst_rtc_alarm_irq_enable,
288};
289
290static struct mrst_rtc mrst_rtc;
291
292/*
293 * When vRTC IRQ is captured by SCU FW, FW will clear the AIE bit in
294 * Reg B, so no need for this driver to clear it
295 */
296static irqreturn_t mrst_rtc_irq(int irq, void *p)
297{
298 u8 irqstat;
299
300 spin_lock(&rtc_lock);
301 /* This read will clear all IRQ flags inside Reg C */
302 irqstat = vrtc_cmos_read(RTC_INTR_FLAGS);
303 spin_unlock(&rtc_lock);
304
305 irqstat &= RTC_IRQMASK | RTC_IRQF;
306 if (is_intr(irqstat)) {
307 rtc_update_irq(p, 1, irqstat);
308 return IRQ_HANDLED;
309 }
310 return IRQ_NONE;
311}
312
313static int vrtc_mrst_do_probe(struct device *dev, struct resource *iomem,
314 int rtc_irq)
315{
316 int retval = 0;
317 unsigned char rtc_control;
318
319 /* There can be only one ... */
320 if (mrst_rtc.dev)
321 return -EBUSY;
322
323 if (!iomem)
324 return -ENODEV;
325
326 iomem = devm_request_mem_region(dev, iomem->start, resource_size(iomem),
327 driver_name);
328 if (!iomem) {
329 dev_dbg(dev, "i/o mem already in use.\n");
330 return -EBUSY;
331 }
332
333 mrst_rtc.irq = rtc_irq;
334 mrst_rtc.dev = dev;
335 dev_set_drvdata(dev, &mrst_rtc);
336
337 mrst_rtc.rtc = devm_rtc_allocate_device(dev);
338 if (IS_ERR(mrst_rtc.rtc))
339 return PTR_ERR(mrst_rtc.rtc);
340
341 mrst_rtc.rtc->ops = &mrst_rtc_ops;
342
343 rename_region(iomem, dev_name(&mrst_rtc.rtc->dev));
344
345 spin_lock_irq(&rtc_lock);
346 mrst_irq_disable(&mrst_rtc, RTC_PIE | RTC_AIE);
347 rtc_control = vrtc_cmos_read(RTC_CONTROL);
348 spin_unlock_irq(&rtc_lock);
349
350 if (!(rtc_control & RTC_24H) || (rtc_control & (RTC_DM_BINARY)))
351 dev_dbg(dev, "TODO: support more than 24-hr BCD mode\n");
352
353 if (rtc_irq) {
354 retval = devm_request_irq(dev, rtc_irq, mrst_rtc_irq,
355 0, dev_name(&mrst_rtc.rtc->dev),
356 mrst_rtc.rtc);
357 if (retval < 0) {
358 dev_dbg(dev, "IRQ %d is already in use, err %d\n",
359 rtc_irq, retval);
360 goto cleanup0;
361 }
362 }
363
364 retval = rtc_register_device(mrst_rtc.rtc);
365 if (retval)
366 goto cleanup0;
367
368 dev_dbg(dev, "initialised\n");
369 return 0;
370
371cleanup0:
372 mrst_rtc.dev = NULL;
373 dev_err(dev, "rtc-mrst: unable to initialise\n");
374 return retval;
375}
376
377static void rtc_mrst_do_shutdown(void)
378{
379 spin_lock_irq(&rtc_lock);
380 mrst_irq_disable(&mrst_rtc, RTC_IRQMASK);
381 spin_unlock_irq(&rtc_lock);
382}
383
384static void rtc_mrst_do_remove(struct device *dev)
385{
386 struct mrst_rtc *mrst = dev_get_drvdata(dev);
387
388 rtc_mrst_do_shutdown();
389
390 mrst->rtc = NULL;
391 mrst->dev = NULL;
392}
393
394#ifdef CONFIG_PM_SLEEP
395static int mrst_suspend(struct device *dev)
396{
397 struct mrst_rtc *mrst = dev_get_drvdata(dev);
398 unsigned char tmp;
399
400 /* Only the alarm might be a wakeup event source */
401 spin_lock_irq(&rtc_lock);
402 mrst->suspend_ctrl = tmp = vrtc_cmos_read(RTC_CONTROL);
403 if (tmp & (RTC_PIE | RTC_AIE)) {
404 unsigned char mask;
405
406 if (device_may_wakeup(dev))
407 mask = RTC_IRQMASK & ~RTC_AIE;
408 else
409 mask = RTC_IRQMASK;
410 tmp &= ~mask;
411 vrtc_cmos_write(tmp, RTC_CONTROL);
412
413 mrst_checkintr(mrst, tmp);
414 }
415 spin_unlock_irq(&rtc_lock);
416
417 if (tmp & RTC_AIE) {
418 mrst->enabled_wake = 1;
419 enable_irq_wake(mrst->irq);
420 }
421
422 dev_dbg(&mrst_rtc.rtc->dev, "suspend%s, ctrl %02x\n",
423 (tmp & RTC_AIE) ? ", alarm may wake" : "",
424 tmp);
425
426 return 0;
427}
428
429/*
430 * We want RTC alarms to wake us from the deep power saving state
431 */
432static inline int mrst_poweroff(struct device *dev)
433{
434 return mrst_suspend(dev);
435}
436
437static int mrst_resume(struct device *dev)
438{
439 struct mrst_rtc *mrst = dev_get_drvdata(dev);
440 unsigned char tmp = mrst->suspend_ctrl;
441
442 /* Re-enable any irqs previously active */
443 if (tmp & RTC_IRQMASK) {
444 unsigned char mask;
445
446 if (mrst->enabled_wake) {
447 disable_irq_wake(mrst->irq);
448 mrst->enabled_wake = 0;
449 }
450
451 spin_lock_irq(&rtc_lock);
452 do {
453 vrtc_cmos_write(tmp, RTC_CONTROL);
454
455 mask = vrtc_cmos_read(RTC_INTR_FLAGS);
456 mask &= (tmp & RTC_IRQMASK) | RTC_IRQF;
457 if (!is_intr(mask))
458 break;
459
460 rtc_update_irq(mrst->rtc, 1, mask);
461 tmp &= ~RTC_AIE;
462 } while (mask & RTC_AIE);
463 spin_unlock_irq(&rtc_lock);
464 }
465
466 dev_dbg(&mrst_rtc.rtc->dev, "resume, ctrl %02x\n", tmp);
467
468 return 0;
469}
470
471static SIMPLE_DEV_PM_OPS(mrst_pm_ops, mrst_suspend, mrst_resume);
472#define MRST_PM_OPS (&mrst_pm_ops)
473
474#else
475#define MRST_PM_OPS NULL
476
477static inline int mrst_poweroff(struct device *dev)
478{
479 return -ENOSYS;
480}
481
482#endif
483
484static int vrtc_mrst_platform_probe(struct platform_device *pdev)
485{
486 return vrtc_mrst_do_probe(&pdev->dev,
487 platform_get_resource(pdev, IORESOURCE_MEM, 0),
488 platform_get_irq(pdev, 0));
489}
490
491static int vrtc_mrst_platform_remove(struct platform_device *pdev)
492{
493 rtc_mrst_do_remove(&pdev->dev);
494 return 0;
495}
496
497static void vrtc_mrst_platform_shutdown(struct platform_device *pdev)
498{
499 if (system_state == SYSTEM_POWER_OFF && !mrst_poweroff(&pdev->dev))
500 return;
501
502 rtc_mrst_do_shutdown();
503}
504
505MODULE_ALIAS("platform:vrtc_mrst");
506
507static struct platform_driver vrtc_mrst_platform_driver = {
508 .probe = vrtc_mrst_platform_probe,
509 .remove = vrtc_mrst_platform_remove,
510 .shutdown = vrtc_mrst_platform_shutdown,
511 .driver = {
512 .name = driver_name,
513 .pm = MRST_PM_OPS,
514 }
515};
516
517module_platform_driver(vrtc_mrst_platform_driver);
518
519MODULE_AUTHOR("Jacob Pan; Feng Tang");
520MODULE_DESCRIPTION("Driver for Moorestown virtual RTC");
521MODULE_LICENSE("GPL");