xref: /openbmc/linux/drivers/rtc/rtc-rs5c313.c (revision 78700c0a)
1 /*
2  * Ricoh RS5C313 RTC device/driver
3  *  Copyright (C) 2007 Nobuhiro Iwamatsu
4  *
5  *  2005-09-19 modifed by kogiidena
6  *
7  * Based on the old drivers/char/rs5c313_rtc.c  by:
8  *  Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
9  *  Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
10  *
11  * Based on code written by Paul Gortmaker.
12  *  Copyright (C) 1996 Paul Gortmaker
13  *
14  * This file is subject to the terms and conditions of the GNU General Public
15  * License.  See the file "COPYING" in the main directory of this archive
16  * for more details.
17  *
18  * Based on other minimal char device drivers, like Alan's
19  * watchdog, Ted's random, etc. etc.
20  *
21  *	1.07	Paul Gortmaker.
22  *	1.08	Miquel van Smoorenburg: disallow certain things on the
23  *		DEC Alpha as the CMOS clock is also used for other things.
24  *	1.09	Nikita Schmidt: epoch support and some Alpha cleanup.
25  *	1.09a	Pete Zaitcev: Sun SPARC
26  *	1.09b	Jeff Garzik: Modularize, init cleanup
27  *	1.09c	Jeff Garzik: SMP cleanup
28  *	1.10    Paul Barton-Davis: add support for async I/O
29  *	1.10a	Andrea Arcangeli: Alpha updates
30  *	1.10b	Andrew Morton: SMP lock fix
31  *	1.10c	Cesar Barros: SMP locking fixes and cleanup
32  *	1.10d	Paul Gortmaker: delete paranoia check in rtc_exit
33  *	1.10e	Maciej W. Rozycki: Handle DECstation's year weirdness.
34  *      1.11    Takashi Iwai: Kernel access functions
35  *			      rtc_register/rtc_unregister/rtc_control
36  *      1.11a   Daniele Bellucci: Audit create_proc_read_entry in rtc_init
37  *	1.12	Venkatesh Pallipadi: Hooks for emulating rtc on HPET base-timer
38  *		CONFIG_HPET_EMULATE_RTC
39  *	1.13	Nobuhiro Iwamatsu: Updata driver.
40  */
41 
42 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
43 
44 #include <linux/module.h>
45 #include <linux/err.h>
46 #include <linux/rtc.h>
47 #include <linux/platform_device.h>
48 #include <linux/bcd.h>
49 #include <linux/delay.h>
50 #include <linux/io.h>
51 
52 #define DRV_NAME	"rs5c313"
53 
54 #ifdef CONFIG_SH_LANDISK
55 /*****************************************************/
56 /* LANDISK dependence part of RS5C313                */
57 /*****************************************************/
58 
59 #define SCSMR1		0xFFE00000
60 #define SCSCR1		0xFFE00008
61 #define SCSMR1_CA	0x80
62 #define SCSCR1_CKE	0x03
63 #define SCSPTR1		0xFFE0001C
64 #define SCSPTR1_EIO	0x80
65 #define SCSPTR1_SPB1IO	0x08
66 #define SCSPTR1_SPB1DT	0x04
67 #define SCSPTR1_SPB0IO	0x02
68 #define SCSPTR1_SPB0DT	0x01
69 
70 #define SDA_OEN		SCSPTR1_SPB1IO
71 #define SDA		SCSPTR1_SPB1DT
72 #define SCL_OEN		SCSPTR1_SPB0IO
73 #define SCL		SCSPTR1_SPB0DT
74 
75 /* RICOH RS5C313 CE port */
76 #define RS5C313_CE	0xB0000003
77 
78 /* RICOH RS5C313 CE port bit */
79 #define RS5C313_CE_RTCCE	0x02
80 
81 /* SCSPTR1 data */
82 unsigned char scsptr1_data;
83 
84 #define RS5C313_CEENABLE    __raw_writeb(RS5C313_CE_RTCCE, RS5C313_CE);
85 #define RS5C313_CEDISABLE   __raw_writeb(0x00, RS5C313_CE)
86 #define RS5C313_MISCOP      __raw_writeb(0x02, 0xB0000008)
87 
88 static void rs5c313_init_port(void)
89 {
90 	/* Set SCK as I/O port and Initialize SCSPTR1 data & I/O port. */
91 	__raw_writeb(__raw_readb(SCSMR1) & ~SCSMR1_CA, SCSMR1);
92 	__raw_writeb(__raw_readb(SCSCR1) & ~SCSCR1_CKE, SCSCR1);
93 
94 	/* And Initialize SCL for RS5C313 clock */
95 	scsptr1_data = __raw_readb(SCSPTR1) | SCL;	/* SCL:H */
96 	__raw_writeb(scsptr1_data, SCSPTR1);
97 	scsptr1_data = __raw_readb(SCSPTR1) | SCL_OEN;	/* SCL output enable */
98 	__raw_writeb(scsptr1_data, SCSPTR1);
99 	RS5C313_CEDISABLE;	/* CE:L */
100 }
101 
102 static void rs5c313_write_data(unsigned char data)
103 {
104 	int i;
105 
106 	for (i = 0; i < 8; i++) {
107 		/* SDA:Write Data */
108 		scsptr1_data = (scsptr1_data & ~SDA) |
109 				((((0x80 >> i) & data) >> (7 - i)) << 2);
110 		__raw_writeb(scsptr1_data, SCSPTR1);
111 		if (i == 0) {
112 			scsptr1_data |= SDA_OEN;	/* SDA:output enable */
113 			__raw_writeb(scsptr1_data, SCSPTR1);
114 		}
115 		ndelay(700);
116 		scsptr1_data &= ~SCL;	/* SCL:L */
117 		__raw_writeb(scsptr1_data, SCSPTR1);
118 		ndelay(700);
119 		scsptr1_data |= SCL;	/* SCL:H */
120 		__raw_writeb(scsptr1_data, SCSPTR1);
121 	}
122 
123 	scsptr1_data &= ~SDA_OEN;	/* SDA:output disable */
124 	__raw_writeb(scsptr1_data, SCSPTR1);
125 }
126 
127 static unsigned char rs5c313_read_data(void)
128 {
129 	int i;
130 	unsigned char data = 0;
131 
132 	for (i = 0; i < 8; i++) {
133 		ndelay(700);
134 		/* SDA:Read Data */
135 		data |= ((__raw_readb(SCSPTR1) & SDA) >> 2) << (7 - i);
136 		scsptr1_data &= ~SCL;	/* SCL:L */
137 		__raw_writeb(scsptr1_data, SCSPTR1);
138 		ndelay(700);
139 		scsptr1_data |= SCL;	/* SCL:H */
140 		__raw_writeb(scsptr1_data, SCSPTR1);
141 	}
142 	return data & 0x0F;
143 }
144 
145 #endif /* CONFIG_SH_LANDISK */
146 
147 /*****************************************************/
148 /* machine independence part of RS5C313              */
149 /*****************************************************/
150 
151 /* RICOH RS5C313 address */
152 #define RS5C313_ADDR_SEC	0x00
153 #define RS5C313_ADDR_SEC10	0x01
154 #define RS5C313_ADDR_MIN	0x02
155 #define RS5C313_ADDR_MIN10	0x03
156 #define RS5C313_ADDR_HOUR	0x04
157 #define RS5C313_ADDR_HOUR10	0x05
158 #define RS5C313_ADDR_WEEK	0x06
159 #define RS5C313_ADDR_INTINTVREG	0x07
160 #define RS5C313_ADDR_DAY	0x08
161 #define RS5C313_ADDR_DAY10	0x09
162 #define RS5C313_ADDR_MON	0x0A
163 #define RS5C313_ADDR_MON10	0x0B
164 #define RS5C313_ADDR_YEAR	0x0C
165 #define RS5C313_ADDR_YEAR10	0x0D
166 #define RS5C313_ADDR_CNTREG	0x0E
167 #define RS5C313_ADDR_TESTREG	0x0F
168 
169 /* RICOH RS5C313 control register */
170 #define RS5C313_CNTREG_ADJ_BSY	0x01
171 #define RS5C313_CNTREG_WTEN_XSTP	0x02
172 #define RS5C313_CNTREG_12_24	0x04
173 #define RS5C313_CNTREG_CTFG	0x08
174 
175 /* RICOH RS5C313 test register */
176 #define RS5C313_TESTREG_TEST	0x01
177 
178 /* RICOH RS5C313 control bit */
179 #define RS5C313_CNTBIT_READ	0x40
180 #define RS5C313_CNTBIT_AD	0x20
181 #define RS5C313_CNTBIT_DT	0x10
182 
183 static unsigned char rs5c313_read_reg(unsigned char addr)
184 {
185 
186 	rs5c313_write_data(addr | RS5C313_CNTBIT_READ | RS5C313_CNTBIT_AD);
187 	return rs5c313_read_data();
188 }
189 
190 static void rs5c313_write_reg(unsigned char addr, unsigned char data)
191 {
192 	data &= 0x0f;
193 	rs5c313_write_data(addr | RS5C313_CNTBIT_AD);
194 	rs5c313_write_data(data | RS5C313_CNTBIT_DT);
195 	return;
196 }
197 
198 static inline unsigned char rs5c313_read_cntreg(void)
199 {
200 	return rs5c313_read_reg(RS5C313_ADDR_CNTREG);
201 }
202 
203 static inline void rs5c313_write_cntreg(unsigned char data)
204 {
205 	rs5c313_write_reg(RS5C313_ADDR_CNTREG, data);
206 }
207 
208 static inline void rs5c313_write_intintvreg(unsigned char data)
209 {
210 	rs5c313_write_reg(RS5C313_ADDR_INTINTVREG, data);
211 }
212 
213 static int rs5c313_rtc_read_time(struct device *dev, struct rtc_time *tm)
214 {
215 	int data;
216 	int cnt;
217 
218 	cnt = 0;
219 	while (1) {
220 		RS5C313_CEENABLE;	/* CE:H */
221 
222 		/* Initialize control reg. 24 hour */
223 		rs5c313_write_cntreg(0x04);
224 
225 		if (!(rs5c313_read_cntreg() & RS5C313_CNTREG_ADJ_BSY))
226 			break;
227 
228 		RS5C313_CEDISABLE;
229 		ndelay(700);	/* CE:L */
230 
231 		if (cnt++ > 100) {
232 			dev_err(dev, "%s: timeout error\n", __func__);
233 			return -EIO;
234 		}
235 	}
236 
237 	data = rs5c313_read_reg(RS5C313_ADDR_SEC);
238 	data |= (rs5c313_read_reg(RS5C313_ADDR_SEC10) << 4);
239 	tm->tm_sec = bcd2bin(data);
240 
241 	data = rs5c313_read_reg(RS5C313_ADDR_MIN);
242 	data |= (rs5c313_read_reg(RS5C313_ADDR_MIN10) << 4);
243 	tm->tm_min = bcd2bin(data);
244 
245 	data = rs5c313_read_reg(RS5C313_ADDR_HOUR);
246 	data |= (rs5c313_read_reg(RS5C313_ADDR_HOUR10) << 4);
247 	tm->tm_hour = bcd2bin(data);
248 
249 	data = rs5c313_read_reg(RS5C313_ADDR_DAY);
250 	data |= (rs5c313_read_reg(RS5C313_ADDR_DAY10) << 4);
251 	tm->tm_mday = bcd2bin(data);
252 
253 	data = rs5c313_read_reg(RS5C313_ADDR_MON);
254 	data |= (rs5c313_read_reg(RS5C313_ADDR_MON10) << 4);
255 	tm->tm_mon = bcd2bin(data) - 1;
256 
257 	data = rs5c313_read_reg(RS5C313_ADDR_YEAR);
258 	data |= (rs5c313_read_reg(RS5C313_ADDR_YEAR10) << 4);
259 	tm->tm_year = bcd2bin(data);
260 
261 	if (tm->tm_year < 70)
262 		tm->tm_year += 100;
263 
264 	data = rs5c313_read_reg(RS5C313_ADDR_WEEK);
265 	tm->tm_wday = bcd2bin(data);
266 
267 	RS5C313_CEDISABLE;
268 	ndelay(700);		/* CE:L */
269 
270 	return 0;
271 }
272 
273 static int rs5c313_rtc_set_time(struct device *dev, struct rtc_time *tm)
274 {
275 	int data;
276 	int cnt;
277 
278 	cnt = 0;
279 	/* busy check. */
280 	while (1) {
281 		RS5C313_CEENABLE;	/* CE:H */
282 
283 		/* Initiatlize control reg. 24 hour */
284 		rs5c313_write_cntreg(0x04);
285 
286 		if (!(rs5c313_read_cntreg() & RS5C313_CNTREG_ADJ_BSY))
287 			break;
288 		RS5C313_MISCOP;
289 		RS5C313_CEDISABLE;
290 		ndelay(700);	/* CE:L */
291 
292 		if (cnt++ > 100) {
293 			dev_err(dev, "%s: timeout error\n", __func__);
294 			return -EIO;
295 		}
296 	}
297 
298 	data = bin2bcd(tm->tm_sec);
299 	rs5c313_write_reg(RS5C313_ADDR_SEC, data);
300 	rs5c313_write_reg(RS5C313_ADDR_SEC10, (data >> 4));
301 
302 	data = bin2bcd(tm->tm_min);
303 	rs5c313_write_reg(RS5C313_ADDR_MIN, data);
304 	rs5c313_write_reg(RS5C313_ADDR_MIN10, (data >> 4));
305 
306 	data = bin2bcd(tm->tm_hour);
307 	rs5c313_write_reg(RS5C313_ADDR_HOUR, data);
308 	rs5c313_write_reg(RS5C313_ADDR_HOUR10, (data >> 4));
309 
310 	data = bin2bcd(tm->tm_mday);
311 	rs5c313_write_reg(RS5C313_ADDR_DAY, data);
312 	rs5c313_write_reg(RS5C313_ADDR_DAY10, (data >> 4));
313 
314 	data = bin2bcd(tm->tm_mon + 1);
315 	rs5c313_write_reg(RS5C313_ADDR_MON, data);
316 	rs5c313_write_reg(RS5C313_ADDR_MON10, (data >> 4));
317 
318 	data = bin2bcd(tm->tm_year % 100);
319 	rs5c313_write_reg(RS5C313_ADDR_YEAR, data);
320 	rs5c313_write_reg(RS5C313_ADDR_YEAR10, (data >> 4));
321 
322 	data = bin2bcd(tm->tm_wday);
323 	rs5c313_write_reg(RS5C313_ADDR_WEEK, data);
324 
325 	RS5C313_CEDISABLE;	/* CE:H */
326 	ndelay(700);
327 
328 	return 0;
329 }
330 
331 static void rs5c313_check_xstp_bit(void)
332 {
333 	struct rtc_time tm;
334 	int cnt;
335 
336 	RS5C313_CEENABLE;	/* CE:H */
337 	if (rs5c313_read_cntreg() & RS5C313_CNTREG_WTEN_XSTP) {
338 		/* INT interval reg. OFF */
339 		rs5c313_write_intintvreg(0x00);
340 		/* Initialize control reg. 24 hour & adjust */
341 		rs5c313_write_cntreg(0x07);
342 
343 		/* busy check. */
344 		for (cnt = 0; cnt < 100; cnt++) {
345 			if (!(rs5c313_read_cntreg() & RS5C313_CNTREG_ADJ_BSY))
346 				break;
347 			RS5C313_MISCOP;
348 		}
349 
350 		memset(&tm, 0, sizeof(struct rtc_time));
351 		tm.tm_mday	= 1;
352 		tm.tm_mon	= 1 - 1;
353 		tm.tm_year	= 2000 - 1900;
354 
355 		rs5c313_rtc_set_time(NULL, &tm);
356 		pr_err("invalid value, resetting to 1 Jan 2000\n");
357 	}
358 	RS5C313_CEDISABLE;
359 	ndelay(700);		/* CE:L */
360 }
361 
362 static const struct rtc_class_ops rs5c313_rtc_ops = {
363 	.read_time = rs5c313_rtc_read_time,
364 	.set_time = rs5c313_rtc_set_time,
365 };
366 
367 static int rs5c313_rtc_probe(struct platform_device *pdev)
368 {
369 	struct rtc_device *rtc = devm_rtc_device_register(&pdev->dev, "rs5c313",
370 				&rs5c313_rtc_ops, THIS_MODULE);
371 
372 	if (IS_ERR(rtc))
373 		return PTR_ERR(rtc);
374 
375 	platform_set_drvdata(pdev, rtc);
376 
377 	return 0;
378 }
379 
380 static struct platform_driver rs5c313_rtc_platform_driver = {
381 	.driver         = {
382 		.name   = DRV_NAME,
383 	},
384 	.probe	= rs5c313_rtc_probe,
385 };
386 
387 static int __init rs5c313_rtc_init(void)
388 {
389 	int err;
390 
391 	err = platform_driver_register(&rs5c313_rtc_platform_driver);
392 	if (err)
393 		return err;
394 
395 	rs5c313_init_port();
396 	rs5c313_check_xstp_bit();
397 
398 	return 0;
399 }
400 
401 static void __exit rs5c313_rtc_exit(void)
402 {
403 	platform_driver_unregister(&rs5c313_rtc_platform_driver);
404 }
405 
406 module_init(rs5c313_rtc_init);
407 module_exit(rs5c313_rtc_exit);
408 
409 MODULE_AUTHOR("kogiidena , Nobuhiro Iwamatsu <iwamatsu@nigauri.org>");
410 MODULE_DESCRIPTION("Ricoh RS5C313 RTC device driver");
411 MODULE_LICENSE("GPL");
412 MODULE_ALIAS("platform:" DRV_NAME);
413