xref: /openbmc/u-boot/drivers/rtc/rx8010sj.c (revision 90c08fa0)
1 /*
2  * Epson RX8010 RTC driver.
3  *
4  * Copyright (c) 2017, General Electric Company
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #include <command.h>
20 #include <common.h>
21 #include <dm.h>
22 #include <i2c.h>
23 #include <rtc.h>
24 
25 /*---------------------------------------------------------------------*/
26 /* #undef DEBUG_RTC */
27 
28 #ifdef DEBUG_RTC
29 #define DEBUGR(fmt, args...) printf(fmt, ##args)
30 #else
31 #define DEBUGR(fmt, args...)
32 #endif
33 /*---------------------------------------------------------------------*/
34 
35 #ifndef CONFIG_SYS_I2C_RTC_ADDR
36 # define CONFIG_SYS_I2C_RTC_ADDR	0x32
37 #endif
38 
39 /*
40  * RTC register addresses
41  */
42 #define RX8010_SEC     0x10
43 #define RX8010_MIN     0x11
44 #define RX8010_HOUR    0x12
45 #define RX8010_WDAY    0x13
46 #define RX8010_MDAY    0x14
47 #define RX8010_MONTH   0x15
48 #define RX8010_YEAR    0x16
49 #define RX8010_YEAR    0x16
50 #define RX8010_RESV17  0x17
51 #define RX8010_ALMIN   0x18
52 #define RX8010_ALHOUR  0x19
53 #define RX8010_ALWDAY  0x1A
54 #define RX8010_TCOUNT0 0x1B
55 #define RX8010_TCOUNT1 0x1C
56 #define RX8010_EXT     0x1D
57 #define RX8010_FLAG    0x1E
58 #define RX8010_CTRL    0x1F
59 /* 0x20 to 0x2F are user registers */
60 #define RX8010_RESV30  0x30
61 #define RX8010_RESV31  0x32
62 #define RX8010_IRQ     0x32
63 
64 #define RX8010_EXT_WADA  BIT(3)
65 
66 #define RX8010_FLAG_VLF  BIT(1)
67 #define RX8010_FLAG_AF   BIT(3)
68 #define RX8010_FLAG_TF   BIT(4)
69 #define RX8010_FLAG_UF   BIT(5)
70 
71 #define RX8010_CTRL_AIE  BIT(3)
72 #define RX8010_CTRL_UIE  BIT(5)
73 #define RX8010_CTRL_STOP BIT(6)
74 #define RX8010_CTRL_TEST BIT(7)
75 
76 #define RX8010_ALARM_AE  BIT(7)
77 
78 #ifdef CONFIG_DM_RTC
79 
80 #define DEV_TYPE struct udevice
81 
82 #else
83 
84 /* Local udevice */
85 struct ludevice {
86 	u8 chip;
87 };
88 
89 #define DEV_TYPE struct ludevice
90 
91 #endif
92 
93 static int rx8010sj_rtc_read8(DEV_TYPE *dev, unsigned int reg)
94 {
95 	u8 val;
96 	int ret;
97 
98 #ifdef CONFIG_DM_RTC
99 	ret = dm_i2c_read(dev, reg, &val, sizeof(val));
100 #else
101 	ret = i2c_read(dev->chip, reg, 1, &val, 1);
102 #endif
103 
104 	return ret < 0 ? ret : val;
105 }
106 
107 static int rx8010sj_rtc_write8(DEV_TYPE *dev, unsigned int reg, int val)
108 {
109 	int ret;
110 	u8 lval = val;
111 
112 #ifdef CONFIG_DM_RTC
113 	ret = dm_i2c_write(dev, reg, &lval, 1);
114 #else
115 	ret = i2c_write(dev->chip, reg, 1, &lval, 1);
116 #endif
117 
118 	return ret < 0 ? ret : 0;
119 }
120 
121 static int validate_time(const struct rtc_time *tm)
122 {
123 	if ((tm->tm_year < 2000) || (tm->tm_year > 2099))
124 		return -EINVAL;
125 
126 	if ((tm->tm_mon < 1) || (tm->tm_mon > 12))
127 		return -EINVAL;
128 
129 	if ((tm->tm_mday < 1) || (tm->tm_mday > 31))
130 		return -EINVAL;
131 
132 	if ((tm->tm_wday < 0) || (tm->tm_wday > 6))
133 		return -EINVAL;
134 
135 	if ((tm->tm_hour < 0) || (tm->tm_hour > 23))
136 		return -EINVAL;
137 
138 	if ((tm->tm_min < 0) || (tm->tm_min > 59))
139 		return -EINVAL;
140 
141 	if ((tm->tm_sec < 0) || (tm->tm_sec > 59))
142 		return -EINVAL;
143 
144 	return 0;
145 }
146 
147 void rx8010sj_rtc_init(DEV_TYPE *dev)
148 {
149 	u8 ctrl[2];
150 	int need_clear = 0, ret = 0;
151 
152 	/* Initialize reserved registers as specified in datasheet */
153 	ret = rx8010sj_rtc_write8(dev, RX8010_RESV17, 0xD8);
154 	if (ret < 0)
155 		goto error;
156 
157 	ret = rx8010sj_rtc_write8(dev, RX8010_RESV30, 0x00);
158 	if (ret < 0)
159 		goto error;
160 
161 	ret = rx8010sj_rtc_write8(dev, RX8010_RESV31, 0x08);
162 	if (ret < 0)
163 		goto error;
164 
165 	ret = rx8010sj_rtc_write8(dev, RX8010_IRQ, 0x00);
166 	if (ret < 0)
167 		goto error;
168 
169 	for (int i = 0; i < 2; i++) {
170 		ret = rx8010sj_rtc_read8(dev, RX8010_FLAG + i);
171 		if (ret < 0)
172 			goto error;
173 
174 		ctrl[i] = ret;
175 	}
176 
177 	if (ctrl[0] & RX8010_FLAG_VLF)
178 		printf("RTC low voltage detected\n");
179 
180 	if (ctrl[0] & RX8010_FLAG_AF) {
181 		printf("Alarm was detected\n");
182 		need_clear = 1;
183 	}
184 
185 	if (ctrl[0] & RX8010_FLAG_TF)
186 		need_clear = 1;
187 
188 	if (ctrl[0] & RX8010_FLAG_UF)
189 		need_clear = 1;
190 
191 	if (need_clear) {
192 		ctrl[0] &= ~(RX8010_FLAG_AF | RX8010_FLAG_TF | RX8010_FLAG_UF);
193 		ret = rx8010sj_rtc_write8(dev, RX8010_FLAG, ctrl[0]);
194 		if (ret < 0)
195 			goto error;
196 	}
197 
198 	return;
199 
200 error:
201 	printf("Error rtc init.\n");
202 }
203 
204 /* Get the current time from the RTC */
205 static int rx8010sj_rtc_get(DEV_TYPE *dev, struct rtc_time *tmp)
206 {
207 	u8 date[7];
208 	int flagreg;
209 	int ret;
210 
211 	flagreg = rx8010sj_rtc_read8(dev, RX8010_FLAG);
212 	if (flagreg < 0) {
213 		DEBUGR("Error reading from RTC. err: %d\n", flagreg);
214 		return -EIO;
215 	}
216 
217 	if (flagreg & RX8010_FLAG_VLF) {
218 		DEBUGR("RTC low voltage detected\n");
219 		return -EINVAL;
220 	}
221 
222 	for (int i = 0; i < 7; i++) {
223 		ret = rx8010sj_rtc_read8(dev, RX8010_SEC + i);
224 		if (ret < 0) {
225 			DEBUGR("Error reading from RTC. err: %d\n", ret);
226 			return -EIO;
227 		}
228 		date[i] = ret;
229 	}
230 
231 	tmp->tm_sec = bcd2bin(date[RX8010_SEC - RX8010_SEC] & 0x7f);
232 	tmp->tm_min = bcd2bin(date[RX8010_MIN - RX8010_SEC] & 0x7f);
233 	tmp->tm_hour = bcd2bin(date[RX8010_HOUR - RX8010_SEC] & 0x3f);
234 	tmp->tm_mday = bcd2bin(date[RX8010_MDAY - RX8010_SEC] & 0x3f);
235 	tmp->tm_mon = bcd2bin(date[RX8010_MONTH - RX8010_SEC] & 0x1f);
236 	tmp->tm_year = bcd2bin(date[RX8010_YEAR - RX8010_SEC]) + 2000;
237 	tmp->tm_wday = 0;
238 	tmp->tm_yday = 0;
239 	tmp->tm_isdst = 0;
240 
241 	DEBUGR("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
242 	       tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
243 	       tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
244 
245 	return 0;
246 }
247 
248 /* Set the RTC */
249 static int rx8010sj_rtc_set(DEV_TYPE *dev, const struct rtc_time *tm)
250 {
251 	u8 date[7];
252 	int ctrl, flagreg;
253 	int ret;
254 
255 	ret = validate_time(tm);
256 	if (ret < 0)
257 		return -EINVAL;
258 
259 	/* set STOP bit before changing clock/calendar */
260 	ctrl = rx8010sj_rtc_read8(dev, RX8010_CTRL);
261 	if (ctrl < 0)
262 		return ctrl;
263 	ret = rx8010sj_rtc_write8(dev, RX8010_CTRL, ctrl | RX8010_CTRL_STOP);
264 	if (ret < 0)
265 		return ret;
266 
267 	date[RX8010_SEC - RX8010_SEC] = bin2bcd(tm->tm_sec);
268 	date[RX8010_MIN - RX8010_SEC] = bin2bcd(tm->tm_min);
269 	date[RX8010_HOUR - RX8010_SEC] = bin2bcd(tm->tm_hour);
270 	date[RX8010_MDAY - RX8010_SEC] = bin2bcd(tm->tm_mday);
271 	date[RX8010_MONTH - RX8010_SEC] = bin2bcd(tm->tm_mon);
272 	date[RX8010_YEAR - RX8010_SEC] = bin2bcd(tm->tm_year - 2000);
273 	date[RX8010_WDAY - RX8010_SEC] = bin2bcd(tm->tm_wday);
274 
275 	for (int i = 0; i < 7; i++) {
276 		ret = rx8010sj_rtc_write8(dev, RX8010_SEC + i, date[i]);
277 		if (ret < 0) {
278 			DEBUGR("Error writing to RTC. err: %d\n", ret);
279 			return -EIO;
280 		}
281 	}
282 
283 	/* clear STOP bit after changing clock/calendar */
284 	ctrl = rx8010sj_rtc_read8(dev, RX8010_CTRL);
285 	if (ctrl < 0)
286 		return ctrl;
287 
288 	ret = rx8010sj_rtc_write8(dev, RX8010_CTRL, ctrl & ~RX8010_CTRL_STOP);
289 	if (ret < 0)
290 		return ret;
291 
292 	flagreg = rx8010sj_rtc_read8(dev, RX8010_FLAG);
293 	if (flagreg < 0)
294 		return flagreg;
295 
296 	if (flagreg & RX8010_FLAG_VLF)
297 		ret = rx8010sj_rtc_write8(dev, RX8010_FLAG,
298 					  flagreg & ~RX8010_FLAG_VLF);
299 
300 	return 0;
301 }
302 
303 /* Reset the RTC. */
304 static int rx8010sj_rtc_reset(DEV_TYPE *dev)
305 {
306 	/* Not needed */
307 	return 0;
308 }
309 
310 #ifndef CONFIG_DM_RTC
311 
312 int rtc_get(struct rtc_time *tm)
313 {
314 	struct ludevice dev = {
315 			.chip = CONFIG_SYS_I2C_RTC_ADDR,
316 	};
317 
318 	return rx8010sj_rtc_get(&dev, tm);
319 }
320 
321 int rtc_set(struct rtc_time *tm)
322 {
323 	struct ludevice dev = {
324 			.chip = CONFIG_SYS_I2C_RTC_ADDR,
325 	};
326 
327 	return rx8010sj_rtc_set(&dev, tm);
328 }
329 
330 void rtc_reset(void)
331 {
332 	struct ludevice dev = {
333 			.chip = CONFIG_SYS_I2C_RTC_ADDR,
334 	};
335 
336 	rx8010sj_rtc_reset(&dev);
337 }
338 
339 void rtc_init(void)
340 {
341 	struct ludevice dev = {
342 			.chip = CONFIG_SYS_I2C_RTC_ADDR,
343 	};
344 
345 	rx8010sj_rtc_init(&dev);
346 }
347 
348 #else
349 
350 static int rx8010sj_probe(struct udevice *dev)
351 {
352 	rx8010sj_rtc_init(&dev);
353 
354 	return 0;
355 }
356 
357 static const struct rtc_ops rx8010sj_rtc_ops = {
358 	.get = rx8010sj_rtc_get,
359 	.set = rx8010sj_rtc_set,
360 	.read8 = rx8010sj_rtc_read8,
361 	.write8 = rx8010sj_rtc_write8,
362 	.reset = rx8010sj_rtc_reset,
363 };
364 
365 static const struct udevice_id rx8010sj_rtc_ids[] = {
366 	{ .compatible = "epson,rx8010sj-rtc" },
367 	{ }
368 };
369 
370 U_BOOT_DRIVER(rx8010sj_rtc) = {
371 	.name	  = "rx8010sj_rtc",
372 	.id	      = UCLASS_RTC,
373 	.probe    = rx8010sj_probe,
374 	.of_match = rx8010sj_rtc_ids,
375 	.ops	  = &rx8010sj_rtc_ops,
376 };
377 
378 #endif
379