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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) ST-Ericsson SA 2010
4 *
5 * Author: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
6 *
7 * RTC clock driver for the RTC part of the AB8500 Power management chip.
8 * Based on RTC clock driver for the AB3100 Analog Baseband Chip by
9 * Linus Walleij <linus.walleij@stericsson.com>
10 */
11
12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/init.h>
15#include <linux/platform_device.h>
16#include <linux/rtc.h>
17#include <linux/mfd/abx500.h>
18#include <linux/mfd/abx500/ab8500.h>
19#include <linux/delay.h>
20#include <linux/of.h>
21#include <linux/pm_wakeirq.h>
22
23#define AB8500_RTC_SOFF_STAT_REG 0x00
24#define AB8500_RTC_CC_CONF_REG 0x01
25#define AB8500_RTC_READ_REQ_REG 0x02
26#define AB8500_RTC_WATCH_TSECMID_REG 0x03
27#define AB8500_RTC_WATCH_TSECHI_REG 0x04
28#define AB8500_RTC_WATCH_TMIN_LOW_REG 0x05
29#define AB8500_RTC_WATCH_TMIN_MID_REG 0x06
30#define AB8500_RTC_WATCH_TMIN_HI_REG 0x07
31#define AB8500_RTC_ALRM_MIN_LOW_REG 0x08
32#define AB8500_RTC_ALRM_MIN_MID_REG 0x09
33#define AB8500_RTC_ALRM_MIN_HI_REG 0x0A
34#define AB8500_RTC_STAT_REG 0x0B
35#define AB8500_RTC_BKUP_CHG_REG 0x0C
36#define AB8500_RTC_FORCE_BKUP_REG 0x0D
37#define AB8500_RTC_CALIB_REG 0x0E
38#define AB8500_RTC_SWITCH_STAT_REG 0x0F
39
40/* RtcReadRequest bits */
41#define RTC_READ_REQUEST 0x01
42#define RTC_WRITE_REQUEST 0x02
43
44/* RtcCtrl bits */
45#define RTC_ALARM_ENA 0x04
46#define RTC_STATUS_DATA 0x01
47
48#define COUNTS_PER_SEC (0xF000 / 60)
49
50static const u8 ab8500_rtc_time_regs[] = {
51 AB8500_RTC_WATCH_TMIN_HI_REG, AB8500_RTC_WATCH_TMIN_MID_REG,
52 AB8500_RTC_WATCH_TMIN_LOW_REG, AB8500_RTC_WATCH_TSECHI_REG,
53 AB8500_RTC_WATCH_TSECMID_REG
54};
55
56static const u8 ab8500_rtc_alarm_regs[] = {
57 AB8500_RTC_ALRM_MIN_HI_REG, AB8500_RTC_ALRM_MIN_MID_REG,
58 AB8500_RTC_ALRM_MIN_LOW_REG
59};
60
61static int ab8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
62{
63 unsigned long timeout = jiffies + HZ;
64 int retval, i;
65 unsigned long mins, secs;
66 unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
67 u8 value;
68
69 /* Request a data read */
70 retval = abx500_set_register_interruptible(dev,
71 AB8500_RTC, AB8500_RTC_READ_REQ_REG, RTC_READ_REQUEST);
72 if (retval < 0)
73 return retval;
74
75 /* Wait for some cycles after enabling the rtc read in ab8500 */
76 while (time_before(jiffies, timeout)) {
77 retval = abx500_get_register_interruptible(dev,
78 AB8500_RTC, AB8500_RTC_READ_REQ_REG, &value);
79 if (retval < 0)
80 return retval;
81
82 if (!(value & RTC_READ_REQUEST))
83 break;
84
85 usleep_range(1000, 5000);
86 }
87
88 /* Read the Watchtime registers */
89 for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
90 retval = abx500_get_register_interruptible(dev,
91 AB8500_RTC, ab8500_rtc_time_regs[i], &value);
92 if (retval < 0)
93 return retval;
94 buf[i] = value;
95 }
96
97 mins = (buf[0] << 16) | (buf[1] << 8) | buf[2];
98
99 secs = (buf[3] << 8) | buf[4];
100 secs = secs / COUNTS_PER_SEC;
101 secs = secs + (mins * 60);
102
103 rtc_time64_to_tm(secs, tm);
104 return 0;
105}
106
107static int ab8500_rtc_set_time(struct device *dev, struct rtc_time *tm)
108{
109 int retval, i;
110 unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
111 unsigned long no_secs, no_mins, secs = 0;
112
113 secs = rtc_tm_to_time64(tm);
114
115 no_mins = secs / 60;
116
117 no_secs = secs % 60;
118 /* Make the seconds count as per the RTC resolution */
119 no_secs = no_secs * COUNTS_PER_SEC;
120
121 buf[4] = no_secs & 0xFF;
122 buf[3] = (no_secs >> 8) & 0xFF;
123
124 buf[2] = no_mins & 0xFF;
125 buf[1] = (no_mins >> 8) & 0xFF;
126 buf[0] = (no_mins >> 16) & 0xFF;
127
128 for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
129 retval = abx500_set_register_interruptible(dev, AB8500_RTC,
130 ab8500_rtc_time_regs[i], buf[i]);
131 if (retval < 0)
132 return retval;
133 }
134
135 /* Request a data write */
136 return abx500_set_register_interruptible(dev, AB8500_RTC,
137 AB8500_RTC_READ_REQ_REG, RTC_WRITE_REQUEST);
138}
139
140static int ab8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
141{
142 int retval, i;
143 u8 rtc_ctrl, value;
144 unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
145 unsigned long secs, mins;
146
147 /* Check if the alarm is enabled or not */
148 retval = abx500_get_register_interruptible(dev, AB8500_RTC,
149 AB8500_RTC_STAT_REG, &rtc_ctrl);
150 if (retval < 0)
151 return retval;
152
153 if (rtc_ctrl & RTC_ALARM_ENA)
154 alarm->enabled = 1;
155 else
156 alarm->enabled = 0;
157
158 alarm->pending = 0;
159
160 for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
161 retval = abx500_get_register_interruptible(dev, AB8500_RTC,
162 ab8500_rtc_alarm_regs[i], &value);
163 if (retval < 0)
164 return retval;
165 buf[i] = value;
166 }
167
168 mins = (buf[0] << 16) | (buf[1] << 8) | (buf[2]);
169 secs = mins * 60;
170
171 rtc_time64_to_tm(secs, &alarm->time);
172
173 return 0;
174}
175
176static int ab8500_rtc_irq_enable(struct device *dev, unsigned int enabled)
177{
178 return abx500_mask_and_set_register_interruptible(dev, AB8500_RTC,
179 AB8500_RTC_STAT_REG, RTC_ALARM_ENA,
180 enabled ? RTC_ALARM_ENA : 0);
181}
182
183static int ab8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
184{
185 int retval, i;
186 unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
187 unsigned long mins, secs = 0, cursec = 0;
188 struct rtc_time curtm;
189
190 /* Get the number of seconds since 1970 */
191 secs = rtc_tm_to_time64(&alarm->time);
192
193 /*
194 * Check whether alarm is set less than 1min.
195 * Since our RTC doesn't support alarm resolution less than 1min,
196 * return -EINVAL, so UIE EMUL can take it up, incase of UIE_ON
197 */
198 ab8500_rtc_read_time(dev, &curtm); /* Read current time */
199 cursec = rtc_tm_to_time64(&curtm);
200 if ((secs - cursec) < 59) {
201 dev_dbg(dev, "Alarm less than 1 minute not supported\r\n");
202 return -EINVAL;
203 }
204
205 mins = secs / 60;
206
207 buf[2] = mins & 0xFF;
208 buf[1] = (mins >> 8) & 0xFF;
209 buf[0] = (mins >> 16) & 0xFF;
210
211 /* Set the alarm time */
212 for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
213 retval = abx500_set_register_interruptible(dev, AB8500_RTC,
214 ab8500_rtc_alarm_regs[i], buf[i]);
215 if (retval < 0)
216 return retval;
217 }
218
219 return ab8500_rtc_irq_enable(dev, alarm->enabled);
220}
221
222static int ab8500_rtc_set_calibration(struct device *dev, int calibration)
223{
224 int retval;
225 u8 rtccal = 0;
226
227 /*
228 * Check that the calibration value (which is in units of 0.5
229 * parts-per-million) is in the AB8500's range for RtcCalibration
230 * register. -128 (0x80) is not permitted because the AB8500 uses
231 * a sign-bit rather than two's complement, so 0x80 is just another
232 * representation of zero.
233 */
234 if ((calibration < -127) || (calibration > 127)) {
235 dev_err(dev, "RtcCalibration value outside permitted range\n");
236 return -EINVAL;
237 }
238
239 /*
240 * The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
241 * so need to convert to this sort of representation before writing
242 * into RtcCalibration register...
243 */
244 if (calibration >= 0)
245 rtccal = 0x7F & calibration;
246 else
247 rtccal = ~(calibration - 1) | 0x80;
248
249 retval = abx500_set_register_interruptible(dev, AB8500_RTC,
250 AB8500_RTC_CALIB_REG, rtccal);
251
252 return retval;
253}
254
255static int ab8500_rtc_get_calibration(struct device *dev, int *calibration)
256{
257 int retval;
258 u8 rtccal = 0;
259
260 retval = abx500_get_register_interruptible(dev, AB8500_RTC,
261 AB8500_RTC_CALIB_REG, &rtccal);
262 if (retval >= 0) {
263 /*
264 * The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
265 * so need to convert value from RtcCalibration register into
266 * a two's complement signed value...
267 */
268 if (rtccal & 0x80)
269 *calibration = 0 - (rtccal & 0x7F);
270 else
271 *calibration = 0x7F & rtccal;
272 }
273
274 return retval;
275}
276
277static ssize_t ab8500_sysfs_store_rtc_calibration(struct device *dev,
278 struct device_attribute *attr,
279 const char *buf, size_t count)
280{
281 int retval;
282 int calibration = 0;
283
284 if (sscanf(buf, " %i ", &calibration) != 1) {
285 dev_err(dev, "Failed to store RTC calibration attribute\n");
286 return -EINVAL;
287 }
288
289 retval = ab8500_rtc_set_calibration(dev, calibration);
290
291 return retval ? retval : count;
292}
293
294static ssize_t ab8500_sysfs_show_rtc_calibration(struct device *dev,
295 struct device_attribute *attr, char *buf)
296{
297 int retval = 0;
298 int calibration = 0;
299
300 retval = ab8500_rtc_get_calibration(dev, &calibration);
301 if (retval < 0) {
302 dev_err(dev, "Failed to read RTC calibration attribute\n");
303 sprintf(buf, "0\n");
304 return retval;
305 }
306
307 return sprintf(buf, "%d\n", calibration);
308}
309
310static DEVICE_ATTR(rtc_calibration, S_IRUGO | S_IWUSR,
311 ab8500_sysfs_show_rtc_calibration,
312 ab8500_sysfs_store_rtc_calibration);
313
314static struct attribute *ab8500_rtc_attrs[] = {
315 &dev_attr_rtc_calibration.attr,
316 NULL
317};
318
319static const struct attribute_group ab8500_rtc_sysfs_files = {
320 .attrs = ab8500_rtc_attrs,
321};
322
323static irqreturn_t rtc_alarm_handler(int irq, void *data)
324{
325 struct rtc_device *rtc = data;
326 unsigned long events = RTC_IRQF | RTC_AF;
327
328 dev_dbg(&rtc->dev, "%s\n", __func__);
329 rtc_update_irq(rtc, 1, events);
330
331 return IRQ_HANDLED;
332}
333
334static const struct rtc_class_ops ab8500_rtc_ops = {
335 .read_time = ab8500_rtc_read_time,
336 .set_time = ab8500_rtc_set_time,
337 .read_alarm = ab8500_rtc_read_alarm,
338 .set_alarm = ab8500_rtc_set_alarm,
339 .alarm_irq_enable = ab8500_rtc_irq_enable,
340};
341
342static const struct platform_device_id ab85xx_rtc_ids[] = {
343 { "ab8500-rtc", (kernel_ulong_t)&ab8500_rtc_ops, },
344 { /* sentinel */ }
345};
346MODULE_DEVICE_TABLE(platform, ab85xx_rtc_ids);
347
348static int ab8500_rtc_probe(struct platform_device *pdev)
349{
350 const struct platform_device_id *platid = platform_get_device_id(pdev);
351 int err;
352 struct rtc_device *rtc;
353 u8 rtc_ctrl;
354 int irq;
355
356 irq = platform_get_irq_byname(pdev, "ALARM");
357 if (irq < 0)
358 return irq;
359
360 /* For RTC supply test */
361 err = abx500_mask_and_set_register_interruptible(&pdev->dev, AB8500_RTC,
362 AB8500_RTC_STAT_REG, RTC_STATUS_DATA, RTC_STATUS_DATA);
363 if (err < 0)
364 return err;
365
366 /* Wait for reset by the PorRtc */
367 usleep_range(1000, 5000);
368
369 err = abx500_get_register_interruptible(&pdev->dev, AB8500_RTC,
370 AB8500_RTC_STAT_REG, &rtc_ctrl);
371 if (err < 0)
372 return err;
373
374 /* Check if the RTC Supply fails */
375 if (!(rtc_ctrl & RTC_STATUS_DATA)) {
376 dev_err(&pdev->dev, "RTC supply failure\n");
377 return -ENODEV;
378 }
379
380 device_init_wakeup(&pdev->dev, true);
381
382 rtc = devm_rtc_allocate_device(&pdev->dev);
383 if (IS_ERR(rtc))
384 return PTR_ERR(rtc);
385
386 rtc->ops = (struct rtc_class_ops *)platid->driver_data;
387
388 err = devm_request_threaded_irq(&pdev->dev, irq, NULL,
389 rtc_alarm_handler, IRQF_ONESHOT,
390 "ab8500-rtc", rtc);
391 if (err < 0)
392 return err;
393
394 dev_pm_set_wake_irq(&pdev->dev, irq);
395 platform_set_drvdata(pdev, rtc);
396
397 rtc->uie_unsupported = 1;
398
399 rtc->range_max = (1ULL << 24) * 60 - 1; // 24-bit minutes + 59 secs
400 rtc->start_secs = RTC_TIMESTAMP_BEGIN_2000;
401 rtc->set_start_time = true;
402
403 err = rtc_add_group(rtc, &ab8500_rtc_sysfs_files);
404 if (err)
405 return err;
406
407 return rtc_register_device(rtc);
408}
409
410static int ab8500_rtc_remove(struct platform_device *pdev)
411{
412 dev_pm_clear_wake_irq(&pdev->dev);
413 device_init_wakeup(&pdev->dev, false);
414
415 return 0;
416}
417
418static struct platform_driver ab8500_rtc_driver = {
419 .driver = {
420 .name = "ab8500-rtc",
421 },
422 .probe = ab8500_rtc_probe,
423 .remove = ab8500_rtc_remove,
424 .id_table = ab85xx_rtc_ids,
425};
426
427module_platform_driver(ab8500_rtc_driver);
428
429MODULE_AUTHOR("Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>");
430MODULE_DESCRIPTION("AB8500 RTC Driver");
431MODULE_LICENSE("GPL v2");
1/*
2 * Copyright (C) ST-Ericsson SA 2010
3 *
4 * License terms: GNU General Public License (GPL) version 2
5 * Author: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
6 *
7 * RTC clock driver for the RTC part of the AB8500 Power management chip.
8 * Based on RTC clock driver for the AB3100 Analog Baseband Chip by
9 * Linus Walleij <linus.walleij@stericsson.com>
10 */
11
12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/init.h>
15#include <linux/platform_device.h>
16#include <linux/rtc.h>
17#include <linux/mfd/abx500.h>
18#include <linux/mfd/abx500/ab8500.h>
19#include <linux/delay.h>
20#include <linux/of.h>
21
22#define AB8500_RTC_SOFF_STAT_REG 0x00
23#define AB8500_RTC_CC_CONF_REG 0x01
24#define AB8500_RTC_READ_REQ_REG 0x02
25#define AB8500_RTC_WATCH_TSECMID_REG 0x03
26#define AB8500_RTC_WATCH_TSECHI_REG 0x04
27#define AB8500_RTC_WATCH_TMIN_LOW_REG 0x05
28#define AB8500_RTC_WATCH_TMIN_MID_REG 0x06
29#define AB8500_RTC_WATCH_TMIN_HI_REG 0x07
30#define AB8500_RTC_ALRM_MIN_LOW_REG 0x08
31#define AB8500_RTC_ALRM_MIN_MID_REG 0x09
32#define AB8500_RTC_ALRM_MIN_HI_REG 0x0A
33#define AB8500_RTC_STAT_REG 0x0B
34#define AB8500_RTC_BKUP_CHG_REG 0x0C
35#define AB8500_RTC_FORCE_BKUP_REG 0x0D
36#define AB8500_RTC_CALIB_REG 0x0E
37#define AB8500_RTC_SWITCH_STAT_REG 0x0F
38#define AB8540_RTC_ALRM_SEC 0x22
39#define AB8540_RTC_ALRM_MIN_LOW_REG 0x23
40#define AB8540_RTC_ALRM_MIN_MID_REG 0x24
41#define AB8540_RTC_ALRM_MIN_HI_REG 0x25
42
43/* RtcReadRequest bits */
44#define RTC_READ_REQUEST 0x01
45#define RTC_WRITE_REQUEST 0x02
46
47/* RtcCtrl bits */
48#define RTC_ALARM_ENA 0x04
49#define RTC_STATUS_DATA 0x01
50
51#define COUNTS_PER_SEC (0xF000 / 60)
52#define AB8500_RTC_EPOCH 2000
53
54static const u8 ab8500_rtc_time_regs[] = {
55 AB8500_RTC_WATCH_TMIN_HI_REG, AB8500_RTC_WATCH_TMIN_MID_REG,
56 AB8500_RTC_WATCH_TMIN_LOW_REG, AB8500_RTC_WATCH_TSECHI_REG,
57 AB8500_RTC_WATCH_TSECMID_REG
58};
59
60static const u8 ab8500_rtc_alarm_regs[] = {
61 AB8500_RTC_ALRM_MIN_HI_REG, AB8500_RTC_ALRM_MIN_MID_REG,
62 AB8500_RTC_ALRM_MIN_LOW_REG
63};
64
65static const u8 ab8540_rtc_alarm_regs[] = {
66 AB8540_RTC_ALRM_MIN_HI_REG, AB8540_RTC_ALRM_MIN_MID_REG,
67 AB8540_RTC_ALRM_MIN_LOW_REG, AB8540_RTC_ALRM_SEC
68};
69
70/* Calculate the seconds from 1970 to 01-01-2000 00:00:00 */
71static unsigned long get_elapsed_seconds(int year)
72{
73 unsigned long secs;
74 struct rtc_time tm = {
75 .tm_year = year - 1900,
76 .tm_mday = 1,
77 };
78
79 /*
80 * This function calculates secs from 1970 and not from
81 * 1900, even if we supply the offset from year 1900.
82 */
83 rtc_tm_to_time(&tm, &secs);
84 return secs;
85}
86
87static int ab8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
88{
89 unsigned long timeout = jiffies + HZ;
90 int retval, i;
91 unsigned long mins, secs;
92 unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
93 u8 value;
94
95 /* Request a data read */
96 retval = abx500_set_register_interruptible(dev,
97 AB8500_RTC, AB8500_RTC_READ_REQ_REG, RTC_READ_REQUEST);
98 if (retval < 0)
99 return retval;
100
101 /* Wait for some cycles after enabling the rtc read in ab8500 */
102 while (time_before(jiffies, timeout)) {
103 retval = abx500_get_register_interruptible(dev,
104 AB8500_RTC, AB8500_RTC_READ_REQ_REG, &value);
105 if (retval < 0)
106 return retval;
107
108 if (!(value & RTC_READ_REQUEST))
109 break;
110
111 usleep_range(1000, 5000);
112 }
113
114 /* Read the Watchtime registers */
115 for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
116 retval = abx500_get_register_interruptible(dev,
117 AB8500_RTC, ab8500_rtc_time_regs[i], &value);
118 if (retval < 0)
119 return retval;
120 buf[i] = value;
121 }
122
123 mins = (buf[0] << 16) | (buf[1] << 8) | buf[2];
124
125 secs = (buf[3] << 8) | buf[4];
126 secs = secs / COUNTS_PER_SEC;
127 secs = secs + (mins * 60);
128
129 /* Add back the initially subtracted number of seconds */
130 secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
131
132 rtc_time_to_tm(secs, tm);
133 return rtc_valid_tm(tm);
134}
135
136static int ab8500_rtc_set_time(struct device *dev, struct rtc_time *tm)
137{
138 int retval, i;
139 unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
140 unsigned long no_secs, no_mins, secs = 0;
141
142 if (tm->tm_year < (AB8500_RTC_EPOCH - 1900)) {
143 dev_dbg(dev, "year should be equal to or greater than %d\n",
144 AB8500_RTC_EPOCH);
145 return -EINVAL;
146 }
147
148 /* Get the number of seconds since 1970 */
149 rtc_tm_to_time(tm, &secs);
150
151 /*
152 * Convert it to the number of seconds since 01-01-2000 00:00:00, since
153 * we only have a small counter in the RTC.
154 */
155 secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
156
157 no_mins = secs / 60;
158
159 no_secs = secs % 60;
160 /* Make the seconds count as per the RTC resolution */
161 no_secs = no_secs * COUNTS_PER_SEC;
162
163 buf[4] = no_secs & 0xFF;
164 buf[3] = (no_secs >> 8) & 0xFF;
165
166 buf[2] = no_mins & 0xFF;
167 buf[1] = (no_mins >> 8) & 0xFF;
168 buf[0] = (no_mins >> 16) & 0xFF;
169
170 for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
171 retval = abx500_set_register_interruptible(dev, AB8500_RTC,
172 ab8500_rtc_time_regs[i], buf[i]);
173 if (retval < 0)
174 return retval;
175 }
176
177 /* Request a data write */
178 return abx500_set_register_interruptible(dev, AB8500_RTC,
179 AB8500_RTC_READ_REQ_REG, RTC_WRITE_REQUEST);
180}
181
182static int ab8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
183{
184 int retval, i;
185 u8 rtc_ctrl, value;
186 unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
187 unsigned long secs, mins;
188
189 /* Check if the alarm is enabled or not */
190 retval = abx500_get_register_interruptible(dev, AB8500_RTC,
191 AB8500_RTC_STAT_REG, &rtc_ctrl);
192 if (retval < 0)
193 return retval;
194
195 if (rtc_ctrl & RTC_ALARM_ENA)
196 alarm->enabled = 1;
197 else
198 alarm->enabled = 0;
199
200 alarm->pending = 0;
201
202 for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
203 retval = abx500_get_register_interruptible(dev, AB8500_RTC,
204 ab8500_rtc_alarm_regs[i], &value);
205 if (retval < 0)
206 return retval;
207 buf[i] = value;
208 }
209
210 mins = (buf[0] << 16) | (buf[1] << 8) | (buf[2]);
211 secs = mins * 60;
212
213 /* Add back the initially subtracted number of seconds */
214 secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
215
216 rtc_time_to_tm(secs, &alarm->time);
217
218 return rtc_valid_tm(&alarm->time);
219}
220
221static int ab8500_rtc_irq_enable(struct device *dev, unsigned int enabled)
222{
223 return abx500_mask_and_set_register_interruptible(dev, AB8500_RTC,
224 AB8500_RTC_STAT_REG, RTC_ALARM_ENA,
225 enabled ? RTC_ALARM_ENA : 0);
226}
227
228static int ab8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
229{
230 int retval, i;
231 unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
232 unsigned long mins, secs = 0, cursec = 0;
233 struct rtc_time curtm;
234
235 if (alarm->time.tm_year < (AB8500_RTC_EPOCH - 1900)) {
236 dev_dbg(dev, "year should be equal to or greater than %d\n",
237 AB8500_RTC_EPOCH);
238 return -EINVAL;
239 }
240
241 /* Get the number of seconds since 1970 */
242 rtc_tm_to_time(&alarm->time, &secs);
243
244 /*
245 * Check whether alarm is set less than 1min.
246 * Since our RTC doesn't support alarm resolution less than 1min,
247 * return -EINVAL, so UIE EMUL can take it up, incase of UIE_ON
248 */
249 ab8500_rtc_read_time(dev, &curtm); /* Read current time */
250 rtc_tm_to_time(&curtm, &cursec);
251 if ((secs - cursec) < 59) {
252 dev_dbg(dev, "Alarm less than 1 minute not supported\r\n");
253 return -EINVAL;
254 }
255
256 /*
257 * Convert it to the number of seconds since 01-01-2000 00:00:00, since
258 * we only have a small counter in the RTC.
259 */
260 secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
261
262 mins = secs / 60;
263
264 buf[2] = mins & 0xFF;
265 buf[1] = (mins >> 8) & 0xFF;
266 buf[0] = (mins >> 16) & 0xFF;
267
268 /* Set the alarm time */
269 for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
270 retval = abx500_set_register_interruptible(dev, AB8500_RTC,
271 ab8500_rtc_alarm_regs[i], buf[i]);
272 if (retval < 0)
273 return retval;
274 }
275
276 return ab8500_rtc_irq_enable(dev, alarm->enabled);
277}
278
279static int ab8540_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
280{
281 int retval, i;
282 unsigned char buf[ARRAY_SIZE(ab8540_rtc_alarm_regs)];
283 unsigned long mins, secs = 0;
284
285 if (alarm->time.tm_year < (AB8500_RTC_EPOCH - 1900)) {
286 dev_dbg(dev, "year should be equal to or greater than %d\n",
287 AB8500_RTC_EPOCH);
288 return -EINVAL;
289 }
290
291 /* Get the number of seconds since 1970 */
292 rtc_tm_to_time(&alarm->time, &secs);
293
294 /*
295 * Convert it to the number of seconds since 01-01-2000 00:00:00
296 */
297 secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
298 mins = secs / 60;
299
300 buf[3] = secs % 60;
301 buf[2] = mins & 0xFF;
302 buf[1] = (mins >> 8) & 0xFF;
303 buf[0] = (mins >> 16) & 0xFF;
304
305 /* Set the alarm time */
306 for (i = 0; i < ARRAY_SIZE(ab8540_rtc_alarm_regs); i++) {
307 retval = abx500_set_register_interruptible(dev, AB8500_RTC,
308 ab8540_rtc_alarm_regs[i], buf[i]);
309 if (retval < 0)
310 return retval;
311 }
312
313 return ab8500_rtc_irq_enable(dev, alarm->enabled);
314}
315
316static int ab8500_rtc_set_calibration(struct device *dev, int calibration)
317{
318 int retval;
319 u8 rtccal = 0;
320
321 /*
322 * Check that the calibration value (which is in units of 0.5
323 * parts-per-million) is in the AB8500's range for RtcCalibration
324 * register. -128 (0x80) is not permitted because the AB8500 uses
325 * a sign-bit rather than two's complement, so 0x80 is just another
326 * representation of zero.
327 */
328 if ((calibration < -127) || (calibration > 127)) {
329 dev_err(dev, "RtcCalibration value outside permitted range\n");
330 return -EINVAL;
331 }
332
333 /*
334 * The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
335 * so need to convert to this sort of representation before writing
336 * into RtcCalibration register...
337 */
338 if (calibration >= 0)
339 rtccal = 0x7F & calibration;
340 else
341 rtccal = ~(calibration - 1) | 0x80;
342
343 retval = abx500_set_register_interruptible(dev, AB8500_RTC,
344 AB8500_RTC_CALIB_REG, rtccal);
345
346 return retval;
347}
348
349static int ab8500_rtc_get_calibration(struct device *dev, int *calibration)
350{
351 int retval;
352 u8 rtccal = 0;
353
354 retval = abx500_get_register_interruptible(dev, AB8500_RTC,
355 AB8500_RTC_CALIB_REG, &rtccal);
356 if (retval >= 0) {
357 /*
358 * The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
359 * so need to convert value from RtcCalibration register into
360 * a two's complement signed value...
361 */
362 if (rtccal & 0x80)
363 *calibration = 0 - (rtccal & 0x7F);
364 else
365 *calibration = 0x7F & rtccal;
366 }
367
368 return retval;
369}
370
371static ssize_t ab8500_sysfs_store_rtc_calibration(struct device *dev,
372 struct device_attribute *attr,
373 const char *buf, size_t count)
374{
375 int retval;
376 int calibration = 0;
377
378 if (sscanf(buf, " %i ", &calibration) != 1) {
379 dev_err(dev, "Failed to store RTC calibration attribute\n");
380 return -EINVAL;
381 }
382
383 retval = ab8500_rtc_set_calibration(dev, calibration);
384
385 return retval ? retval : count;
386}
387
388static ssize_t ab8500_sysfs_show_rtc_calibration(struct device *dev,
389 struct device_attribute *attr, char *buf)
390{
391 int retval = 0;
392 int calibration = 0;
393
394 retval = ab8500_rtc_get_calibration(dev, &calibration);
395 if (retval < 0) {
396 dev_err(dev, "Failed to read RTC calibration attribute\n");
397 sprintf(buf, "0\n");
398 return retval;
399 }
400
401 return sprintf(buf, "%d\n", calibration);
402}
403
404static DEVICE_ATTR(rtc_calibration, S_IRUGO | S_IWUSR,
405 ab8500_sysfs_show_rtc_calibration,
406 ab8500_sysfs_store_rtc_calibration);
407
408static int ab8500_sysfs_rtc_register(struct device *dev)
409{
410 return device_create_file(dev, &dev_attr_rtc_calibration);
411}
412
413static void ab8500_sysfs_rtc_unregister(struct device *dev)
414{
415 device_remove_file(dev, &dev_attr_rtc_calibration);
416}
417
418static irqreturn_t rtc_alarm_handler(int irq, void *data)
419{
420 struct rtc_device *rtc = data;
421 unsigned long events = RTC_IRQF | RTC_AF;
422
423 dev_dbg(&rtc->dev, "%s\n", __func__);
424 rtc_update_irq(rtc, 1, events);
425
426 return IRQ_HANDLED;
427}
428
429static const struct rtc_class_ops ab8500_rtc_ops = {
430 .read_time = ab8500_rtc_read_time,
431 .set_time = ab8500_rtc_set_time,
432 .read_alarm = ab8500_rtc_read_alarm,
433 .set_alarm = ab8500_rtc_set_alarm,
434 .alarm_irq_enable = ab8500_rtc_irq_enable,
435};
436
437static const struct rtc_class_ops ab8540_rtc_ops = {
438 .read_time = ab8500_rtc_read_time,
439 .set_time = ab8500_rtc_set_time,
440 .read_alarm = ab8500_rtc_read_alarm,
441 .set_alarm = ab8540_rtc_set_alarm,
442 .alarm_irq_enable = ab8500_rtc_irq_enable,
443};
444
445static struct platform_device_id ab85xx_rtc_ids[] = {
446 { "ab8500-rtc", (kernel_ulong_t)&ab8500_rtc_ops, },
447 { "ab8540-rtc", (kernel_ulong_t)&ab8540_rtc_ops, },
448};
449
450static int ab8500_rtc_probe(struct platform_device *pdev)
451{
452 const struct platform_device_id *platid = platform_get_device_id(pdev);
453 int err;
454 struct rtc_device *rtc;
455 u8 rtc_ctrl;
456 int irq;
457
458 irq = platform_get_irq_byname(pdev, "ALARM");
459 if (irq < 0)
460 return irq;
461
462 /* For RTC supply test */
463 err = abx500_mask_and_set_register_interruptible(&pdev->dev, AB8500_RTC,
464 AB8500_RTC_STAT_REG, RTC_STATUS_DATA, RTC_STATUS_DATA);
465 if (err < 0)
466 return err;
467
468 /* Wait for reset by the PorRtc */
469 usleep_range(1000, 5000);
470
471 err = abx500_get_register_interruptible(&pdev->dev, AB8500_RTC,
472 AB8500_RTC_STAT_REG, &rtc_ctrl);
473 if (err < 0)
474 return err;
475
476 /* Check if the RTC Supply fails */
477 if (!(rtc_ctrl & RTC_STATUS_DATA)) {
478 dev_err(&pdev->dev, "RTC supply failure\n");
479 return -ENODEV;
480 }
481
482 device_init_wakeup(&pdev->dev, true);
483
484 rtc = devm_rtc_device_register(&pdev->dev, "ab8500-rtc",
485 (struct rtc_class_ops *)platid->driver_data,
486 THIS_MODULE);
487 if (IS_ERR(rtc)) {
488 dev_err(&pdev->dev, "Registration failed\n");
489 err = PTR_ERR(rtc);
490 return err;
491 }
492
493 err = devm_request_threaded_irq(&pdev->dev, irq, NULL,
494 rtc_alarm_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT,
495 "ab8500-rtc", rtc);
496 if (err < 0)
497 return err;
498
499 platform_set_drvdata(pdev, rtc);
500
501 err = ab8500_sysfs_rtc_register(&pdev->dev);
502 if (err) {
503 dev_err(&pdev->dev, "sysfs RTC failed to register\n");
504 return err;
505 }
506
507 return 0;
508}
509
510static int ab8500_rtc_remove(struct platform_device *pdev)
511{
512 ab8500_sysfs_rtc_unregister(&pdev->dev);
513
514 return 0;
515}
516
517static struct platform_driver ab8500_rtc_driver = {
518 .driver = {
519 .name = "ab8500-rtc",
520 .owner = THIS_MODULE,
521 },
522 .probe = ab8500_rtc_probe,
523 .remove = ab8500_rtc_remove,
524 .id_table = ab85xx_rtc_ids,
525};
526
527module_platform_driver(ab8500_rtc_driver);
528
529MODULE_AUTHOR("Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>");
530MODULE_DESCRIPTION("AB8500 RTC Driver");
531MODULE_LICENSE("GPL v2");