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af873fce | 1 | // SPDX-License-Identifier: GPL-2.0-only |
0af62f4d VS |
2 | /* |
3 | * Copyright (C) ST-Ericsson SA 2010 | |
4 | * | |
0af62f4d VS |
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> | |
47c16975 | 17 | #include <linux/mfd/abx500.h> |
ee66e653 | 18 | #include <linux/mfd/abx500/ab8500.h> |
0af62f4d | 19 | #include <linux/delay.h> |
ad49fcbe | 20 | #include <linux/of.h> |
93a6f916 | 21 | #include <linux/pm_wakeirq.h> |
0af62f4d | 22 | |
47c16975 MW |
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 | |
0af62f4d VS |
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) | |
0af62f4d | 49 | |
47c16975 | 50 | static const u8 ab8500_rtc_time_regs[] = { |
0af62f4d VS |
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 | ||
47c16975 | 56 | static const u8 ab8500_rtc_alarm_regs[] = { |
0af62f4d VS |
57 | AB8500_RTC_ALRM_MIN_HI_REG, AB8500_RTC_ALRM_MIN_MID_REG, |
58 | AB8500_RTC_ALRM_MIN_LOW_REG | |
59 | }; | |
60 | ||
0af62f4d VS |
61 | static int ab8500_rtc_read_time(struct device *dev, struct rtc_time *tm) |
62 | { | |
0af62f4d VS |
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)]; | |
47c16975 | 67 | u8 value; |
0af62f4d VS |
68 | |
69 | /* Request a data read */ | |
47c16975 MW |
70 | retval = abx500_set_register_interruptible(dev, |
71 | AB8500_RTC, AB8500_RTC_READ_REQ_REG, RTC_READ_REQUEST); | |
0af62f4d VS |
72 | if (retval < 0) |
73 | return retval; | |
74 | ||
064407f1 BJ |
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); | |
0af62f4d VS |
86 | } |
87 | ||
88 | /* Read the Watchtime registers */ | |
89 | for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) { | |
47c16975 MW |
90 | retval = abx500_get_register_interruptible(dev, |
91 | AB8500_RTC, ab8500_rtc_time_regs[i], &value); | |
0af62f4d VS |
92 | if (retval < 0) |
93 | return retval; | |
47c16975 | 94 | buf[i] = value; |
0af62f4d VS |
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 | ||
0af62f4d | 103 | rtc_time_to_tm(secs, tm); |
ab62670e | 104 | return 0; |
0af62f4d VS |
105 | } |
106 | ||
107 | static int ab8500_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
108 | { | |
0af62f4d VS |
109 | int retval, i; |
110 | unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)]; | |
111 | unsigned long no_secs, no_mins, secs = 0; | |
112 | ||
0af62f4d VS |
113 | rtc_tm_to_time(tm, &secs); |
114 | ||
0af62f4d VS |
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++) { | |
47c16975 MW |
129 | retval = abx500_set_register_interruptible(dev, AB8500_RTC, |
130 | ab8500_rtc_time_regs[i], buf[i]); | |
0af62f4d VS |
131 | if (retval < 0) |
132 | return retval; | |
133 | } | |
134 | ||
135 | /* Request a data write */ | |
47c16975 MW |
136 | return abx500_set_register_interruptible(dev, AB8500_RTC, |
137 | AB8500_RTC_READ_REQ_REG, RTC_WRITE_REQUEST); | |
0af62f4d VS |
138 | } |
139 | ||
140 | static int ab8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) | |
141 | { | |
0af62f4d | 142 | int retval, i; |
47c16975 | 143 | u8 rtc_ctrl, value; |
0af62f4d VS |
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 */ | |
47c16975 MW |
148 | retval = abx500_get_register_interruptible(dev, AB8500_RTC, |
149 | AB8500_RTC_STAT_REG, &rtc_ctrl); | |
150 | if (retval < 0) | |
151 | return retval; | |
0af62f4d VS |
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++) { | |
47c16975 MW |
161 | retval = abx500_get_register_interruptible(dev, AB8500_RTC, |
162 | ab8500_rtc_alarm_regs[i], &value); | |
0af62f4d VS |
163 | if (retval < 0) |
164 | return retval; | |
47c16975 | 165 | buf[i] = value; |
0af62f4d VS |
166 | } |
167 | ||
168 | mins = (buf[0] << 16) | (buf[1] << 8) | (buf[2]); | |
169 | secs = mins * 60; | |
170 | ||
0af62f4d VS |
171 | rtc_time_to_tm(secs, &alarm->time); |
172 | ||
9a90a5bc | 173 | return 0; |
0af62f4d VS |
174 | } |
175 | ||
176 | static int ab8500_rtc_irq_enable(struct device *dev, unsigned int enabled) | |
177 | { | |
47c16975 MW |
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); | |
0af62f4d VS |
181 | } |
182 | ||
183 | static int ab8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) | |
184 | { | |
0af62f4d VS |
185 | int retval, i; |
186 | unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)]; | |
dc43d4a2 RC |
187 | unsigned long mins, secs = 0, cursec = 0; |
188 | struct rtc_time curtm; | |
0af62f4d | 189 | |
0af62f4d VS |
190 | /* Get the number of seconds since 1970 */ |
191 | rtc_tm_to_time(&alarm->time, &secs); | |
192 | ||
dc43d4a2 RC |
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 | rtc_tm_to_time(&curtm, &cursec); | |
200 | if ((secs - cursec) < 59) { | |
201 | dev_dbg(dev, "Alarm less than 1 minute not supported\r\n"); | |
202 | return -EINVAL; | |
203 | } | |
204 | ||
0af62f4d VS |
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++) { | |
47c16975 MW |
213 | retval = abx500_set_register_interruptible(dev, AB8500_RTC, |
214 | ab8500_rtc_alarm_regs[i], buf[i]); | |
0af62f4d VS |
215 | if (retval < 0) |
216 | return retval; | |
217 | } | |
218 | ||
219 | return ab8500_rtc_irq_enable(dev, alarm->enabled); | |
220 | } | |
221 | ||
dda367ac MG |
222 | static 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 | ||
255 | static 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 | ||
277 | static 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 | ||
294 | static 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 | ||
310 | static DEVICE_ATTR(rtc_calibration, S_IRUGO | S_IWUSR, | |
311 | ab8500_sysfs_show_rtc_calibration, | |
312 | ab8500_sysfs_store_rtc_calibration); | |
313 | ||
b56295dd AB |
314 | static struct attribute *ab8500_rtc_attrs[] = { |
315 | &dev_attr_rtc_calibration.attr, | |
316 | NULL | |
317 | }; | |
dda367ac | 318 | |
b56295dd AB |
319 | static const struct attribute_group ab8500_rtc_sysfs_files = { |
320 | .attrs = ab8500_rtc_attrs, | |
321 | }; | |
dda367ac | 322 | |
0af62f4d VS |
323 | static 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 | ||
334 | static 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 | ||
9a72f410 | 342 | static const struct platform_device_id ab85xx_rtc_ids[] = { |
25d053cf | 343 | { "ab8500-rtc", (kernel_ulong_t)&ab8500_rtc_ops, }, |
8a67e931 | 344 | { /* sentinel */ } |
25d053cf | 345 | }; |
63074cc3 | 346 | MODULE_DEVICE_TABLE(platform, ab85xx_rtc_ids); |
25d053cf | 347 | |
5a167f45 | 348 | static int ab8500_rtc_probe(struct platform_device *pdev) |
0af62f4d | 349 | { |
25d053cf | 350 | const struct platform_device_id *platid = platform_get_device_id(pdev); |
0af62f4d VS |
351 | int err; |
352 | struct rtc_device *rtc; | |
47c16975 | 353 | u8 rtc_ctrl; |
0af62f4d VS |
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 */ | |
47c16975 MW |
361 | err = abx500_mask_and_set_register_interruptible(&pdev->dev, AB8500_RTC, |
362 | AB8500_RTC_STAT_REG, RTC_STATUS_DATA, RTC_STATUS_DATA); | |
0af62f4d VS |
363 | if (err < 0) |
364 | return err; | |
365 | ||
366 | /* Wait for reset by the PorRtc */ | |
012e52e1 | 367 | usleep_range(1000, 5000); |
0af62f4d | 368 | |
47c16975 MW |
369 | err = abx500_get_register_interruptible(&pdev->dev, AB8500_RTC, |
370 | AB8500_RTC_STAT_REG, &rtc_ctrl); | |
371 | if (err < 0) | |
372 | return err; | |
0af62f4d VS |
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 | ||
b62581e6 AL |
380 | device_init_wakeup(&pdev->dev, true); |
381 | ||
b56295dd AB |
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; | |
0af62f4d | 387 | |
fa11f7e7 | 388 | err = devm_request_threaded_irq(&pdev->dev, irq, NULL, |
93a6f916 | 389 | rtc_alarm_handler, IRQF_ONESHOT, |
fa11f7e7 JH |
390 | "ab8500-rtc", rtc); |
391 | if (err < 0) | |
0af62f4d | 392 | return err; |
0af62f4d | 393 | |
93a6f916 | 394 | dev_pm_set_wake_irq(&pdev->dev, irq); |
0af62f4d VS |
395 | platform_set_drvdata(pdev, rtc); |
396 | ||
c594d678 XP |
397 | rtc->uie_unsupported = 1; |
398 | ||
38ab97ae AB |
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 | ||
b56295dd AB |
403 | err = rtc_add_group(rtc, &ab8500_rtc_sysfs_files); |
404 | if (err) | |
405 | return err; | |
406 | ||
407 | return rtc_register_device(rtc); | |
0af62f4d VS |
408 | } |
409 | ||
5a167f45 | 410 | static int ab8500_rtc_remove(struct platform_device *pdev) |
0af62f4d | 411 | { |
93a6f916 SH |
412 | dev_pm_clear_wake_irq(&pdev->dev); |
413 | device_init_wakeup(&pdev->dev, false); | |
dda367ac | 414 | |
0af62f4d VS |
415 | return 0; |
416 | } | |
417 | ||
418 | static struct platform_driver ab8500_rtc_driver = { | |
419 | .driver = { | |
420 | .name = "ab8500-rtc", | |
0af62f4d VS |
421 | }, |
422 | .probe = ab8500_rtc_probe, | |
5a167f45 | 423 | .remove = ab8500_rtc_remove, |
25d053cf | 424 | .id_table = ab85xx_rtc_ids, |
0af62f4d VS |
425 | }; |
426 | ||
0c4eae66 | 427 | module_platform_driver(ab8500_rtc_driver); |
0af62f4d | 428 | |
0af62f4d VS |
429 | MODULE_AUTHOR("Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>"); |
430 | MODULE_DESCRIPTION("AB8500 RTC Driver"); | |
431 | MODULE_LICENSE("GPL v2"); |