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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 | ||
a5965a31 | 103 | rtc_time64_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 | ||
a5965a31 | 113 | secs = rtc_tm_to_time64(tm); |
0af62f4d | 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 | ||
a5965a31 | 171 | rtc_time64_to_tm(secs, &alarm->time); |
0af62f4d | 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)]; | |
a5f82803 | 187 | unsigned long mins; |
0af62f4d | 188 | |
a5f82803 | 189 | mins = (unsigned long)rtc_tm_to_time64(&alarm->time) / 60; |
0af62f4d VS |
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++) { | |
47c16975 MW |
197 | retval = abx500_set_register_interruptible(dev, AB8500_RTC, |
198 | ab8500_rtc_alarm_regs[i], buf[i]); | |
0af62f4d VS |
199 | if (retval < 0) |
200 | return retval; | |
201 | } | |
202 | ||
203 | return ab8500_rtc_irq_enable(dev, alarm->enabled); | |
204 | } | |
205 | ||
dda367ac MG |
206 | static 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 | ||
239 | static 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 | ||
261 | static 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 | ||
278 | static 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 | ||
294 | static DEVICE_ATTR(rtc_calibration, S_IRUGO | S_IWUSR, | |
295 | ab8500_sysfs_show_rtc_calibration, | |
296 | ab8500_sysfs_store_rtc_calibration); | |
297 | ||
b56295dd AB |
298 | static struct attribute *ab8500_rtc_attrs[] = { |
299 | &dev_attr_rtc_calibration.attr, | |
300 | NULL | |
301 | }; | |
dda367ac | 302 | |
b56295dd AB |
303 | static const struct attribute_group ab8500_rtc_sysfs_files = { |
304 | .attrs = ab8500_rtc_attrs, | |
305 | }; | |
dda367ac | 306 | |
0af62f4d VS |
307 | static 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 | ||
318 | static 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 | ||
9a72f410 | 326 | static const struct platform_device_id ab85xx_rtc_ids[] = { |
25d053cf | 327 | { "ab8500-rtc", (kernel_ulong_t)&ab8500_rtc_ops, }, |
8a67e931 | 328 | { /* sentinel */ } |
25d053cf | 329 | }; |
63074cc3 | 330 | MODULE_DEVICE_TABLE(platform, ab85xx_rtc_ids); |
25d053cf | 331 | |
5a167f45 | 332 | static int ab8500_rtc_probe(struct platform_device *pdev) |
0af62f4d | 333 | { |
25d053cf | 334 | const struct platform_device_id *platid = platform_get_device_id(pdev); |
0af62f4d VS |
335 | int err; |
336 | struct rtc_device *rtc; | |
47c16975 | 337 | u8 rtc_ctrl; |
0af62f4d VS |
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 */ | |
47c16975 MW |
345 | err = abx500_mask_and_set_register_interruptible(&pdev->dev, AB8500_RTC, |
346 | AB8500_RTC_STAT_REG, RTC_STATUS_DATA, RTC_STATUS_DATA); | |
0af62f4d VS |
347 | if (err < 0) |
348 | return err; | |
349 | ||
350 | /* Wait for reset by the PorRtc */ | |
012e52e1 | 351 | usleep_range(1000, 5000); |
0af62f4d | 352 | |
47c16975 MW |
353 | err = abx500_get_register_interruptible(&pdev->dev, AB8500_RTC, |
354 | AB8500_RTC_STAT_REG, &rtc_ctrl); | |
355 | if (err < 0) | |
356 | return err; | |
0af62f4d VS |
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 | ||
b62581e6 AL |
364 | device_init_wakeup(&pdev->dev, true); |
365 | ||
b56295dd AB |
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; | |
0af62f4d | 371 | |
fa11f7e7 | 372 | err = devm_request_threaded_irq(&pdev->dev, irq, NULL, |
93a6f916 | 373 | rtc_alarm_handler, IRQF_ONESHOT, |
fa11f7e7 JH |
374 | "ab8500-rtc", rtc); |
375 | if (err < 0) | |
0af62f4d | 376 | return err; |
0af62f4d | 377 | |
93a6f916 | 378 | dev_pm_set_wake_irq(&pdev->dev, irq); |
0af62f4d VS |
379 | platform_set_drvdata(pdev, rtc); |
380 | ||
a5f82803 AB |
381 | set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->features); |
382 | clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features); | |
c594d678 | 383 | |
38ab97ae AB |
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 | ||
b56295dd AB |
388 | err = rtc_add_group(rtc, &ab8500_rtc_sysfs_files); |
389 | if (err) | |
390 | return err; | |
391 | ||
fdcfd854 | 392 | return devm_rtc_register_device(rtc); |
0af62f4d VS |
393 | } |
394 | ||
8a700af1 | 395 | static void ab8500_rtc_remove(struct platform_device *pdev) |
0af62f4d | 396 | { |
93a6f916 SH |
397 | dev_pm_clear_wake_irq(&pdev->dev); |
398 | device_init_wakeup(&pdev->dev, false); | |
0af62f4d VS |
399 | } |
400 | ||
401 | static struct platform_driver ab8500_rtc_driver = { | |
402 | .driver = { | |
403 | .name = "ab8500-rtc", | |
0af62f4d VS |
404 | }, |
405 | .probe = ab8500_rtc_probe, | |
8a700af1 | 406 | .remove_new = ab8500_rtc_remove, |
25d053cf | 407 | .id_table = ab85xx_rtc_ids, |
0af62f4d VS |
408 | }; |
409 | ||
0c4eae66 | 410 | module_platform_driver(ab8500_rtc_driver); |
0af62f4d | 411 | |
0af62f4d VS |
412 | MODULE_AUTHOR("Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>"); |
413 | MODULE_DESCRIPTION("AB8500 RTC Driver"); | |
414 | MODULE_LICENSE("GPL v2"); |