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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;
188
189 mins = (unsigned long)rtc_tm_to_time64(&alarm->time) / 60;
190
191 buf[2] = mins & 0xFF;
192 buf[1] = (mins >> 8) & 0xFF;
193 buf[0] = (mins >> 16) & 0xFF;
194
195 /* Set the alarm time */
196 for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
197 retval = abx500_set_register_interruptible(dev, AB8500_RTC,
198 ab8500_rtc_alarm_regs[i], buf[i]);
199 if (retval < 0)
200 return retval;
201 }
202
203 return ab8500_rtc_irq_enable(dev, alarm->enabled);
204}
205
206static int ab8500_rtc_set_calibration(struct device *dev, int calibration)
207{
208 int retval;
209 u8 rtccal = 0;
210
211 /*
212 * Check that the calibration value (which is in units of 0.5
213 * parts-per-million) is in the AB8500's range for RtcCalibration
214 * register. -128 (0x80) is not permitted because the AB8500 uses
215 * a sign-bit rather than two's complement, so 0x80 is just another
216 * representation of zero.
217 */
218 if ((calibration < -127) || (calibration > 127)) {
219 dev_err(dev, "RtcCalibration value outside permitted range\n");
220 return -EINVAL;
221 }
222
223 /*
224 * The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
225 * so need to convert to this sort of representation before writing
226 * into RtcCalibration register...
227 */
228 if (calibration >= 0)
229 rtccal = 0x7F & calibration;
230 else
231 rtccal = ~(calibration - 1) | 0x80;
232
233 retval = abx500_set_register_interruptible(dev, AB8500_RTC,
234 AB8500_RTC_CALIB_REG, rtccal);
235
236 return retval;
237}
238
239static int ab8500_rtc_get_calibration(struct device *dev, int *calibration)
240{
241 int retval;
242 u8 rtccal = 0;
243
244 retval = abx500_get_register_interruptible(dev, AB8500_RTC,
245 AB8500_RTC_CALIB_REG, &rtccal);
246 if (retval >= 0) {
247 /*
248 * The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
249 * so need to convert value from RtcCalibration register into
250 * a two's complement signed value...
251 */
252 if (rtccal & 0x80)
253 *calibration = 0 - (rtccal & 0x7F);
254 else
255 *calibration = 0x7F & rtccal;
256 }
257
258 return retval;
259}
260
261static ssize_t ab8500_sysfs_store_rtc_calibration(struct device *dev,
262 struct device_attribute *attr,
263 const char *buf, size_t count)
264{
265 int retval;
266 int calibration = 0;
267
268 if (sscanf(buf, " %i ", &calibration) != 1) {
269 dev_err(dev, "Failed to store RTC calibration attribute\n");
270 return -EINVAL;
271 }
272
273 retval = ab8500_rtc_set_calibration(dev, calibration);
274
275 return retval ? retval : count;
276}
277
278static ssize_t ab8500_sysfs_show_rtc_calibration(struct device *dev,
279 struct device_attribute *attr, char *buf)
280{
281 int retval = 0;
282 int calibration = 0;
283
284 retval = ab8500_rtc_get_calibration(dev, &calibration);
285 if (retval < 0) {
286 dev_err(dev, "Failed to read RTC calibration attribute\n");
287 sprintf(buf, "0\n");
288 return retval;
289 }
290
291 return sprintf(buf, "%d\n", calibration);
292}
293
294static DEVICE_ATTR(rtc_calibration, S_IRUGO | S_IWUSR,
295 ab8500_sysfs_show_rtc_calibration,
296 ab8500_sysfs_store_rtc_calibration);
297
298static struct attribute *ab8500_rtc_attrs[] = {
299 &dev_attr_rtc_calibration.attr,
300 NULL
301};
302
303static const struct attribute_group ab8500_rtc_sysfs_files = {
304 .attrs = ab8500_rtc_attrs,
305};
306
307static irqreturn_t rtc_alarm_handler(int irq, void *data)
308{
309 struct rtc_device *rtc = data;
310 unsigned long events = RTC_IRQF | RTC_AF;
311
312 dev_dbg(&rtc->dev, "%s\n", __func__);
313 rtc_update_irq(rtc, 1, events);
314
315 return IRQ_HANDLED;
316}
317
318static const struct rtc_class_ops ab8500_rtc_ops = {
319 .read_time = ab8500_rtc_read_time,
320 .set_time = ab8500_rtc_set_time,
321 .read_alarm = ab8500_rtc_read_alarm,
322 .set_alarm = ab8500_rtc_set_alarm,
323 .alarm_irq_enable = ab8500_rtc_irq_enable,
324};
325
326static const struct platform_device_id ab85xx_rtc_ids[] = {
327 { "ab8500-rtc", (kernel_ulong_t)&ab8500_rtc_ops, },
328 { /* sentinel */ }
329};
330MODULE_DEVICE_TABLE(platform, ab85xx_rtc_ids);
331
332static int ab8500_rtc_probe(struct platform_device *pdev)
333{
334 const struct platform_device_id *platid = platform_get_device_id(pdev);
335 int err;
336 struct rtc_device *rtc;
337 u8 rtc_ctrl;
338 int irq;
339
340 irq = platform_get_irq_byname(pdev, "ALARM");
341 if (irq < 0)
342 return irq;
343
344 /* For RTC supply test */
345 err = abx500_mask_and_set_register_interruptible(&pdev->dev, AB8500_RTC,
346 AB8500_RTC_STAT_REG, RTC_STATUS_DATA, RTC_STATUS_DATA);
347 if (err < 0)
348 return err;
349
350 /* Wait for reset by the PorRtc */
351 usleep_range(1000, 5000);
352
353 err = abx500_get_register_interruptible(&pdev->dev, AB8500_RTC,
354 AB8500_RTC_STAT_REG, &rtc_ctrl);
355 if (err < 0)
356 return err;
357
358 /* Check if the RTC Supply fails */
359 if (!(rtc_ctrl & RTC_STATUS_DATA)) {
360 dev_err(&pdev->dev, "RTC supply failure\n");
361 return -ENODEV;
362 }
363
364 device_init_wakeup(&pdev->dev, true);
365
366 rtc = devm_rtc_allocate_device(&pdev->dev);
367 if (IS_ERR(rtc))
368 return PTR_ERR(rtc);
369
370 rtc->ops = (struct rtc_class_ops *)platid->driver_data;
371
372 err = devm_request_threaded_irq(&pdev->dev, irq, NULL,
373 rtc_alarm_handler, IRQF_ONESHOT,
374 "ab8500-rtc", rtc);
375 if (err < 0)
376 return err;
377
378 dev_pm_set_wake_irq(&pdev->dev, irq);
379 platform_set_drvdata(pdev, rtc);
380
381 set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->features);
382 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
383
384 rtc->range_max = (1ULL << 24) * 60 - 1; // 24-bit minutes + 59 secs
385 rtc->start_secs = RTC_TIMESTAMP_BEGIN_2000;
386 rtc->set_start_time = true;
387
388 err = rtc_add_group(rtc, &ab8500_rtc_sysfs_files);
389 if (err)
390 return err;
391
392 return devm_rtc_register_device(rtc);
393}
394
395static int ab8500_rtc_remove(struct platform_device *pdev)
396{
397 dev_pm_clear_wake_irq(&pdev->dev);
398 device_init_wakeup(&pdev->dev, false);
399
400 return 0;
401}
402
403static struct platform_driver ab8500_rtc_driver = {
404 .driver = {
405 .name = "ab8500-rtc",
406 },
407 .probe = ab8500_rtc_probe,
408 .remove = ab8500_rtc_remove,
409 .id_table = ab85xx_rtc_ids,
410};
411
412module_platform_driver(ab8500_rtc_driver);
413
414MODULE_AUTHOR("Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>");
415MODULE_DESCRIPTION("AB8500 RTC Driver");
416MODULE_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
39/* RtcReadRequest bits */
40#define RTC_READ_REQUEST 0x01
41#define RTC_WRITE_REQUEST 0x02
42
43/* RtcCtrl bits */
44#define RTC_ALARM_ENA 0x04
45#define RTC_STATUS_DATA 0x01
46
47#define COUNTS_PER_SEC (0xF000 / 60)
48#define AB8500_RTC_EPOCH 2000
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
61/* Calculate the seconds from 1970 to 01-01-2000 00:00:00 */
62static unsigned long get_elapsed_seconds(int year)
63{
64 unsigned long secs;
65 struct rtc_time tm = {
66 .tm_year = year - 1900,
67 .tm_mday = 1,
68 };
69
70 /*
71 * This function calculates secs from 1970 and not from
72 * 1900, even if we supply the offset from year 1900.
73 */
74 rtc_tm_to_time(&tm, &secs);
75 return secs;
76}
77
78static int ab8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
79{
80 unsigned long timeout = jiffies + HZ;
81 int retval, i;
82 unsigned long mins, secs;
83 unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
84 u8 value;
85
86 /* Request a data read */
87 retval = abx500_set_register_interruptible(dev,
88 AB8500_RTC, AB8500_RTC_READ_REQ_REG, RTC_READ_REQUEST);
89 if (retval < 0)
90 return retval;
91
92 /* Early AB8500 chips will not clear the rtc read request bit */
93 if (abx500_get_chip_id(dev) == 0) {
94 usleep_range(1000, 1000);
95 } else {
96 /* Wait for some cycles after enabling the rtc read in ab8500 */
97 while (time_before(jiffies, timeout)) {
98 retval = abx500_get_register_interruptible(dev,
99 AB8500_RTC, AB8500_RTC_READ_REQ_REG, &value);
100 if (retval < 0)
101 return retval;
102
103 if (!(value & RTC_READ_REQUEST))
104 break;
105
106 usleep_range(1000, 5000);
107 }
108 }
109
110 /* Read the Watchtime registers */
111 for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
112 retval = abx500_get_register_interruptible(dev,
113 AB8500_RTC, ab8500_rtc_time_regs[i], &value);
114 if (retval < 0)
115 return retval;
116 buf[i] = value;
117 }
118
119 mins = (buf[0] << 16) | (buf[1] << 8) | buf[2];
120
121 secs = (buf[3] << 8) | buf[4];
122 secs = secs / COUNTS_PER_SEC;
123 secs = secs + (mins * 60);
124
125 /* Add back the initially subtracted number of seconds */
126 secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
127
128 rtc_time_to_tm(secs, tm);
129 return rtc_valid_tm(tm);
130}
131
132static int ab8500_rtc_set_time(struct device *dev, struct rtc_time *tm)
133{
134 int retval, i;
135 unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
136 unsigned long no_secs, no_mins, secs = 0;
137
138 if (tm->tm_year < (AB8500_RTC_EPOCH - 1900)) {
139 dev_dbg(dev, "year should be equal to or greater than %d\n",
140 AB8500_RTC_EPOCH);
141 return -EINVAL;
142 }
143
144 /* Get the number of seconds since 1970 */
145 rtc_tm_to_time(tm, &secs);
146
147 /*
148 * Convert it to the number of seconds since 01-01-2000 00:00:00, since
149 * we only have a small counter in the RTC.
150 */
151 secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
152
153 no_mins = secs / 60;
154
155 no_secs = secs % 60;
156 /* Make the seconds count as per the RTC resolution */
157 no_secs = no_secs * COUNTS_PER_SEC;
158
159 buf[4] = no_secs & 0xFF;
160 buf[3] = (no_secs >> 8) & 0xFF;
161
162 buf[2] = no_mins & 0xFF;
163 buf[1] = (no_mins >> 8) & 0xFF;
164 buf[0] = (no_mins >> 16) & 0xFF;
165
166 for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
167 retval = abx500_set_register_interruptible(dev, AB8500_RTC,
168 ab8500_rtc_time_regs[i], buf[i]);
169 if (retval < 0)
170 return retval;
171 }
172
173 /* Request a data write */
174 return abx500_set_register_interruptible(dev, AB8500_RTC,
175 AB8500_RTC_READ_REQ_REG, RTC_WRITE_REQUEST);
176}
177
178static int ab8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
179{
180 int retval, i;
181 u8 rtc_ctrl, value;
182 unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
183 unsigned long secs, mins;
184
185 /* Check if the alarm is enabled or not */
186 retval = abx500_get_register_interruptible(dev, AB8500_RTC,
187 AB8500_RTC_STAT_REG, &rtc_ctrl);
188 if (retval < 0)
189 return retval;
190
191 if (rtc_ctrl & RTC_ALARM_ENA)
192 alarm->enabled = 1;
193 else
194 alarm->enabled = 0;
195
196 alarm->pending = 0;
197
198 for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
199 retval = abx500_get_register_interruptible(dev, AB8500_RTC,
200 ab8500_rtc_alarm_regs[i], &value);
201 if (retval < 0)
202 return retval;
203 buf[i] = value;
204 }
205
206 mins = (buf[0] << 16) | (buf[1] << 8) | (buf[2]);
207 secs = mins * 60;
208
209 /* Add back the initially subtracted number of seconds */
210 secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
211
212 rtc_time_to_tm(secs, &alarm->time);
213
214 return rtc_valid_tm(&alarm->time);
215}
216
217static int ab8500_rtc_irq_enable(struct device *dev, unsigned int enabled)
218{
219 return abx500_mask_and_set_register_interruptible(dev, AB8500_RTC,
220 AB8500_RTC_STAT_REG, RTC_ALARM_ENA,
221 enabled ? RTC_ALARM_ENA : 0);
222}
223
224static int ab8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
225{
226 int retval, i;
227 unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
228 unsigned long mins, secs = 0;
229
230 if (alarm->time.tm_year < (AB8500_RTC_EPOCH - 1900)) {
231 dev_dbg(dev, "year should be equal to or greater than %d\n",
232 AB8500_RTC_EPOCH);
233 return -EINVAL;
234 }
235
236 /* Get the number of seconds since 1970 */
237 rtc_tm_to_time(&alarm->time, &secs);
238
239 /*
240 * Convert it to the number of seconds since 01-01-2000 00:00:00, since
241 * we only have a small counter in the RTC.
242 */
243 secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
244
245 mins = secs / 60;
246
247 buf[2] = mins & 0xFF;
248 buf[1] = (mins >> 8) & 0xFF;
249 buf[0] = (mins >> 16) & 0xFF;
250
251 /* Set the alarm time */
252 for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
253 retval = abx500_set_register_interruptible(dev, AB8500_RTC,
254 ab8500_rtc_alarm_regs[i], buf[i]);
255 if (retval < 0)
256 return retval;
257 }
258
259 return ab8500_rtc_irq_enable(dev, alarm->enabled);
260}
261
262
263static int ab8500_rtc_set_calibration(struct device *dev, int calibration)
264{
265 int retval;
266 u8 rtccal = 0;
267
268 /*
269 * Check that the calibration value (which is in units of 0.5
270 * parts-per-million) is in the AB8500's range for RtcCalibration
271 * register. -128 (0x80) is not permitted because the AB8500 uses
272 * a sign-bit rather than two's complement, so 0x80 is just another
273 * representation of zero.
274 */
275 if ((calibration < -127) || (calibration > 127)) {
276 dev_err(dev, "RtcCalibration value outside permitted range\n");
277 return -EINVAL;
278 }
279
280 /*
281 * The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
282 * so need to convert to this sort of representation before writing
283 * into RtcCalibration register...
284 */
285 if (calibration >= 0)
286 rtccal = 0x7F & calibration;
287 else
288 rtccal = ~(calibration - 1) | 0x80;
289
290 retval = abx500_set_register_interruptible(dev, AB8500_RTC,
291 AB8500_RTC_CALIB_REG, rtccal);
292
293 return retval;
294}
295
296static int ab8500_rtc_get_calibration(struct device *dev, int *calibration)
297{
298 int retval;
299 u8 rtccal = 0;
300
301 retval = abx500_get_register_interruptible(dev, AB8500_RTC,
302 AB8500_RTC_CALIB_REG, &rtccal);
303 if (retval >= 0) {
304 /*
305 * The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
306 * so need to convert value from RtcCalibration register into
307 * a two's complement signed value...
308 */
309 if (rtccal & 0x80)
310 *calibration = 0 - (rtccal & 0x7F);
311 else
312 *calibration = 0x7F & rtccal;
313 }
314
315 return retval;
316}
317
318static ssize_t ab8500_sysfs_store_rtc_calibration(struct device *dev,
319 struct device_attribute *attr,
320 const char *buf, size_t count)
321{
322 int retval;
323 int calibration = 0;
324
325 if (sscanf(buf, " %i ", &calibration) != 1) {
326 dev_err(dev, "Failed to store RTC calibration attribute\n");
327 return -EINVAL;
328 }
329
330 retval = ab8500_rtc_set_calibration(dev, calibration);
331
332 return retval ? retval : count;
333}
334
335static ssize_t ab8500_sysfs_show_rtc_calibration(struct device *dev,
336 struct device_attribute *attr, char *buf)
337{
338 int retval = 0;
339 int calibration = 0;
340
341 retval = ab8500_rtc_get_calibration(dev, &calibration);
342 if (retval < 0) {
343 dev_err(dev, "Failed to read RTC calibration attribute\n");
344 sprintf(buf, "0\n");
345 return retval;
346 }
347
348 return sprintf(buf, "%d\n", calibration);
349}
350
351static DEVICE_ATTR(rtc_calibration, S_IRUGO | S_IWUSR,
352 ab8500_sysfs_show_rtc_calibration,
353 ab8500_sysfs_store_rtc_calibration);
354
355static int ab8500_sysfs_rtc_register(struct device *dev)
356{
357 return device_create_file(dev, &dev_attr_rtc_calibration);
358}
359
360static void ab8500_sysfs_rtc_unregister(struct device *dev)
361{
362 device_remove_file(dev, &dev_attr_rtc_calibration);
363}
364
365static irqreturn_t rtc_alarm_handler(int irq, void *data)
366{
367 struct rtc_device *rtc = data;
368 unsigned long events = RTC_IRQF | RTC_AF;
369
370 dev_dbg(&rtc->dev, "%s\n", __func__);
371 rtc_update_irq(rtc, 1, events);
372
373 return IRQ_HANDLED;
374}
375
376static const struct rtc_class_ops ab8500_rtc_ops = {
377 .read_time = ab8500_rtc_read_time,
378 .set_time = ab8500_rtc_set_time,
379 .read_alarm = ab8500_rtc_read_alarm,
380 .set_alarm = ab8500_rtc_set_alarm,
381 .alarm_irq_enable = ab8500_rtc_irq_enable,
382};
383
384static int __devinit ab8500_rtc_probe(struct platform_device *pdev)
385{
386 int err;
387 struct rtc_device *rtc;
388 u8 rtc_ctrl;
389 int irq;
390
391 irq = platform_get_irq_byname(pdev, "ALARM");
392 if (irq < 0)
393 return irq;
394
395 /* For RTC supply test */
396 err = abx500_mask_and_set_register_interruptible(&pdev->dev, AB8500_RTC,
397 AB8500_RTC_STAT_REG, RTC_STATUS_DATA, RTC_STATUS_DATA);
398 if (err < 0)
399 return err;
400
401 /* Wait for reset by the PorRtc */
402 usleep_range(1000, 5000);
403
404 err = abx500_get_register_interruptible(&pdev->dev, AB8500_RTC,
405 AB8500_RTC_STAT_REG, &rtc_ctrl);
406 if (err < 0)
407 return err;
408
409 /* Check if the RTC Supply fails */
410 if (!(rtc_ctrl & RTC_STATUS_DATA)) {
411 dev_err(&pdev->dev, "RTC supply failure\n");
412 return -ENODEV;
413 }
414
415 device_init_wakeup(&pdev->dev, true);
416
417 rtc = rtc_device_register("ab8500-rtc", &pdev->dev, &ab8500_rtc_ops,
418 THIS_MODULE);
419 if (IS_ERR(rtc)) {
420 dev_err(&pdev->dev, "Registration failed\n");
421 err = PTR_ERR(rtc);
422 return err;
423 }
424
425 err = request_threaded_irq(irq, NULL, rtc_alarm_handler,
426 IRQF_NO_SUSPEND | IRQF_ONESHOT, "ab8500-rtc", rtc);
427 if (err < 0) {
428 rtc_device_unregister(rtc);
429 return err;
430 }
431
432 platform_set_drvdata(pdev, rtc);
433
434 err = ab8500_sysfs_rtc_register(&pdev->dev);
435 if (err) {
436 dev_err(&pdev->dev, "sysfs RTC failed to register\n");
437 return err;
438 }
439
440 return 0;
441}
442
443static int __devexit ab8500_rtc_remove(struct platform_device *pdev)
444{
445 struct rtc_device *rtc = platform_get_drvdata(pdev);
446 int irq = platform_get_irq_byname(pdev, "ALARM");
447
448 ab8500_sysfs_rtc_unregister(&pdev->dev);
449
450 free_irq(irq, rtc);
451 rtc_device_unregister(rtc);
452 platform_set_drvdata(pdev, NULL);
453
454 return 0;
455}
456
457static const struct of_device_id ab8500_rtc_match[] = {
458 { .compatible = "stericsson,ab8500-rtc", },
459 {}
460};
461
462static struct platform_driver ab8500_rtc_driver = {
463 .driver = {
464 .name = "ab8500-rtc",
465 .owner = THIS_MODULE,
466 .of_match_table = ab8500_rtc_match,
467 },
468 .probe = ab8500_rtc_probe,
469 .remove = __devexit_p(ab8500_rtc_remove),
470};
471
472module_platform_driver(ab8500_rtc_driver);
473
474MODULE_AUTHOR("Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>");
475MODULE_DESCRIPTION("AB8500 RTC Driver");
476MODULE_LICENSE("GPL v2");