xref: /linux/drivers/rtc/rtc-rs5c313.c (revision cc04a46f11ea046ed53e2c832ae29e4790f7e35f)
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 #define DRV_VERSION	"1.13"
54 
55 #ifdef CONFIG_SH_LANDISK
56 /*****************************************************/
57 /* LANDISK dependence part of RS5C313                */
58 /*****************************************************/
59 
60 #define SCSMR1		0xFFE00000
61 #define SCSCR1		0xFFE00008
62 #define SCSMR1_CA	0x80
63 #define SCSCR1_CKE	0x03
64 #define SCSPTR1		0xFFE0001C
65 #define SCSPTR1_EIO	0x80
66 #define SCSPTR1_SPB1IO	0x08
67 #define SCSPTR1_SPB1DT	0x04
68 #define SCSPTR1_SPB0IO	0x02
69 #define SCSPTR1_SPB0DT	0x01
70 
71 #define SDA_OEN		SCSPTR1_SPB1IO
72 #define SDA		SCSPTR1_SPB1DT
73 #define SCL_OEN		SCSPTR1_SPB0IO
74 #define SCL		SCSPTR1_SPB0DT
75 
76 /* RICOH RS5C313 CE port */
77 #define RS5C313_CE	0xB0000003
78 
79 /* RICOH RS5C313 CE port bit */
80 #define RS5C313_CE_RTCCE	0x02
81 
82 /* SCSPTR1 data */
83 unsigned char scsptr1_data;
84 
85 #define RS5C313_CEENABLE    __raw_writeb(RS5C313_CE_RTCCE, RS5C313_CE);
86 #define RS5C313_CEDISABLE   __raw_writeb(0x00, RS5C313_CE)
87 #define RS5C313_MISCOP      __raw_writeb(0x02, 0xB0000008)
88 
89 static void rs5c313_init_port(void)
90 {
91 	/* Set SCK as I/O port and Initialize SCSPTR1 data & I/O port. */
92 	__raw_writeb(__raw_readb(SCSMR1) & ~SCSMR1_CA, SCSMR1);
93 	__raw_writeb(__raw_readb(SCSCR1) & ~SCSCR1_CKE, SCSCR1);
94 
95 	/* And Initialize SCL for RS5C313 clock */
96 	scsptr1_data = __raw_readb(SCSPTR1) | SCL;	/* SCL:H */
97 	__raw_writeb(scsptr1_data, SCSPTR1);
98 	scsptr1_data = __raw_readb(SCSPTR1) | SCL_OEN;	/* SCL output enable */
99 	__raw_writeb(scsptr1_data, SCSPTR1);
100 	RS5C313_CEDISABLE;	/* CE:L */
101 }
102 
103 static void rs5c313_write_data(unsigned char data)
104 {
105 	int i;
106 
107 	for (i = 0; i < 8; i++) {
108 		/* SDA:Write Data */
109 		scsptr1_data = (scsptr1_data & ~SDA) |
110 				((((0x80 >> i) & data) >> (7 - i)) << 2);
111 		__raw_writeb(scsptr1_data, SCSPTR1);
112 		if (i == 0) {
113 			scsptr1_data |= SDA_OEN;	/* SDA:output enable */
114 			__raw_writeb(scsptr1_data, SCSPTR1);
115 		}
116 		ndelay(700);
117 		scsptr1_data &= ~SCL;	/* SCL:L */
118 		__raw_writeb(scsptr1_data, SCSPTR1);
119 		ndelay(700);
120 		scsptr1_data |= SCL;	/* SCL:H */
121 		__raw_writeb(scsptr1_data, SCSPTR1);
122 	}
123 
124 	scsptr1_data &= ~SDA_OEN;	/* SDA:output disable */
125 	__raw_writeb(scsptr1_data, SCSPTR1);
126 }
127 
128 static unsigned char rs5c313_read_data(void)
129 {
130 	int i;
131 	unsigned char data = 0;
132 
133 	for (i = 0; i < 8; i++) {
134 		ndelay(700);
135 		/* SDA:Read Data */
136 		data |= ((__raw_readb(SCSPTR1) & SDA) >> 2) << (7 - i);
137 		scsptr1_data &= ~SCL;	/* SCL:L */
138 		__raw_writeb(scsptr1_data, SCSPTR1);
139 		ndelay(700);
140 		scsptr1_data |= SCL;	/* SCL:H */
141 		__raw_writeb(scsptr1_data, SCSPTR1);
142 	}
143 	return data & 0x0F;
144 }
145 
146 #endif /* CONFIG_SH_LANDISK */
147 
148 /*****************************************************/
149 /* machine independence part of RS5C313              */
150 /*****************************************************/
151 
152 /* RICOH RS5C313 address */
153 #define RS5C313_ADDR_SEC	0x00
154 #define RS5C313_ADDR_SEC10	0x01
155 #define RS5C313_ADDR_MIN	0x02
156 #define RS5C313_ADDR_MIN10	0x03
157 #define RS5C313_ADDR_HOUR	0x04
158 #define RS5C313_ADDR_HOUR10	0x05
159 #define RS5C313_ADDR_WEEK	0x06
160 #define RS5C313_ADDR_INTINTVREG	0x07
161 #define RS5C313_ADDR_DAY	0x08
162 #define RS5C313_ADDR_DAY10	0x09
163 #define RS5C313_ADDR_MON	0x0A
164 #define RS5C313_ADDR_MON10	0x0B
165 #define RS5C313_ADDR_YEAR	0x0C
166 #define RS5C313_ADDR_YEAR10	0x0D
167 #define RS5C313_ADDR_CNTREG	0x0E
168 #define RS5C313_ADDR_TESTREG	0x0F
169 
170 /* RICOH RS5C313 control register */
171 #define RS5C313_CNTREG_ADJ_BSY	0x01
172 #define RS5C313_CNTREG_WTEN_XSTP	0x02
173 #define RS5C313_CNTREG_12_24	0x04
174 #define RS5C313_CNTREG_CTFG	0x08
175 
176 /* RICOH RS5C313 test register */
177 #define RS5C313_TESTREG_TEST	0x01
178 
179 /* RICOH RS5C313 control bit */
180 #define RS5C313_CNTBIT_READ	0x40
181 #define RS5C313_CNTBIT_AD	0x20
182 #define RS5C313_CNTBIT_DT	0x10
183 
184 static unsigned char rs5c313_read_reg(unsigned char addr)
185 {
186 
187 	rs5c313_write_data(addr | RS5C313_CNTBIT_READ | RS5C313_CNTBIT_AD);
188 	return rs5c313_read_data();
189 }
190 
191 static void rs5c313_write_reg(unsigned char addr, unsigned char data)
192 {
193 	data &= 0x0f;
194 	rs5c313_write_data(addr | RS5C313_CNTBIT_AD);
195 	rs5c313_write_data(data | RS5C313_CNTBIT_DT);
196 	return;
197 }
198 
199 static inline unsigned char rs5c313_read_cntreg(void)
200 {
201 	return rs5c313_read_reg(RS5C313_ADDR_CNTREG);
202 }
203 
204 static inline void rs5c313_write_cntreg(unsigned char data)
205 {
206 	rs5c313_write_reg(RS5C313_ADDR_CNTREG, data);
207 }
208 
209 static inline void rs5c313_write_intintvreg(unsigned char data)
210 {
211 	rs5c313_write_reg(RS5C313_ADDR_INTINTVREG, data);
212 }
213 
214 static int rs5c313_rtc_read_time(struct device *dev, struct rtc_time *tm)
215 {
216 	int data;
217 	int cnt;
218 
219 	cnt = 0;
220 	while (1) {
221 		RS5C313_CEENABLE;	/* CE:H */
222 
223 		/* Initialize control reg. 24 hour */
224 		rs5c313_write_cntreg(0x04);
225 
226 		if (!(rs5c313_read_cntreg() & RS5C313_CNTREG_ADJ_BSY))
227 			break;
228 
229 		RS5C313_CEDISABLE;
230 		ndelay(700);	/* CE:L */
231 
232 		if (cnt++ > 100) {
233 			dev_err(dev, "%s: timeout error\n", __func__);
234 			return -EIO;
235 		}
236 	}
237 
238 	data = rs5c313_read_reg(RS5C313_ADDR_SEC);
239 	data |= (rs5c313_read_reg(RS5C313_ADDR_SEC10) << 4);
240 	tm->tm_sec = bcd2bin(data);
241 
242 	data = rs5c313_read_reg(RS5C313_ADDR_MIN);
243 	data |= (rs5c313_read_reg(RS5C313_ADDR_MIN10) << 4);
244 	tm->tm_min = bcd2bin(data);
245 
246 	data = rs5c313_read_reg(RS5C313_ADDR_HOUR);
247 	data |= (rs5c313_read_reg(RS5C313_ADDR_HOUR10) << 4);
248 	tm->tm_hour = bcd2bin(data);
249 
250 	data = rs5c313_read_reg(RS5C313_ADDR_DAY);
251 	data |= (rs5c313_read_reg(RS5C313_ADDR_DAY10) << 4);
252 	tm->tm_mday = bcd2bin(data);
253 
254 	data = rs5c313_read_reg(RS5C313_ADDR_MON);
255 	data |= (rs5c313_read_reg(RS5C313_ADDR_MON10) << 4);
256 	tm->tm_mon = bcd2bin(data) - 1;
257 
258 	data = rs5c313_read_reg(RS5C313_ADDR_YEAR);
259 	data |= (rs5c313_read_reg(RS5C313_ADDR_YEAR10) << 4);
260 	tm->tm_year = bcd2bin(data);
261 
262 	if (tm->tm_year < 70)
263 		tm->tm_year += 100;
264 
265 	data = rs5c313_read_reg(RS5C313_ADDR_WEEK);
266 	tm->tm_wday = bcd2bin(data);
267 
268 	RS5C313_CEDISABLE;
269 	ndelay(700);		/* CE:L */
270 
271 	return 0;
272 }
273 
274 static int rs5c313_rtc_set_time(struct device *dev, struct rtc_time *tm)
275 {
276 	int data;
277 	int cnt;
278 
279 	cnt = 0;
280 	/* busy check. */
281 	while (1) {
282 		RS5C313_CEENABLE;	/* CE:H */
283 
284 		/* Initiatlize control reg. 24 hour */
285 		rs5c313_write_cntreg(0x04);
286 
287 		if (!(rs5c313_read_cntreg() & RS5C313_CNTREG_ADJ_BSY))
288 			break;
289 		RS5C313_MISCOP;
290 		RS5C313_CEDISABLE;
291 		ndelay(700);	/* CE:L */
292 
293 		if (cnt++ > 100) {
294 			dev_err(dev, "%s: timeout error\n", __func__);
295 			return -EIO;
296 		}
297 	}
298 
299 	data = bin2bcd(tm->tm_sec);
300 	rs5c313_write_reg(RS5C313_ADDR_SEC, data);
301 	rs5c313_write_reg(RS5C313_ADDR_SEC10, (data >> 4));
302 
303 	data = bin2bcd(tm->tm_min);
304 	rs5c313_write_reg(RS5C313_ADDR_MIN, data);
305 	rs5c313_write_reg(RS5C313_ADDR_MIN10, (data >> 4));
306 
307 	data = bin2bcd(tm->tm_hour);
308 	rs5c313_write_reg(RS5C313_ADDR_HOUR, data);
309 	rs5c313_write_reg(RS5C313_ADDR_HOUR10, (data >> 4));
310 
311 	data = bin2bcd(tm->tm_mday);
312 	rs5c313_write_reg(RS5C313_ADDR_DAY, data);
313 	rs5c313_write_reg(RS5C313_ADDR_DAY10, (data >> 4));
314 
315 	data = bin2bcd(tm->tm_mon + 1);
316 	rs5c313_write_reg(RS5C313_ADDR_MON, data);
317 	rs5c313_write_reg(RS5C313_ADDR_MON10, (data >> 4));
318 
319 	data = bin2bcd(tm->tm_year % 100);
320 	rs5c313_write_reg(RS5C313_ADDR_YEAR, data);
321 	rs5c313_write_reg(RS5C313_ADDR_YEAR10, (data >> 4));
322 
323 	data = bin2bcd(tm->tm_wday);
324 	rs5c313_write_reg(RS5C313_ADDR_WEEK, data);
325 
326 	RS5C313_CEDISABLE;	/* CE:H */
327 	ndelay(700);
328 
329 	return 0;
330 }
331 
332 static void rs5c313_check_xstp_bit(void)
333 {
334 	struct rtc_time tm;
335 	int cnt;
336 
337 	RS5C313_CEENABLE;	/* CE:H */
338 	if (rs5c313_read_cntreg() & RS5C313_CNTREG_WTEN_XSTP) {
339 		/* INT interval reg. OFF */
340 		rs5c313_write_intintvreg(0x00);
341 		/* Initialize control reg. 24 hour & adjust */
342 		rs5c313_write_cntreg(0x07);
343 
344 		/* busy check. */
345 		for (cnt = 0; cnt < 100; cnt++) {
346 			if (!(rs5c313_read_cntreg() & RS5C313_CNTREG_ADJ_BSY))
347 				break;
348 			RS5C313_MISCOP;
349 		}
350 
351 		memset(&tm, 0, sizeof(struct rtc_time));
352 		tm.tm_mday	= 1;
353 		tm.tm_mon	= 1 - 1;
354 		tm.tm_year	= 2000 - 1900;
355 
356 		rs5c313_rtc_set_time(NULL, &tm);
357 		pr_err("invalid value, resetting to 1 Jan 2000\n");
358 	}
359 	RS5C313_CEDISABLE;
360 	ndelay(700);		/* CE:L */
361 }
362 
363 static const struct rtc_class_ops rs5c313_rtc_ops = {
364 	.read_time = rs5c313_rtc_read_time,
365 	.set_time = rs5c313_rtc_set_time,
366 };
367 
368 static int rs5c313_rtc_probe(struct platform_device *pdev)
369 {
370 	struct rtc_device *rtc = devm_rtc_device_register(&pdev->dev, "rs5c313",
371 				&rs5c313_rtc_ops, THIS_MODULE);
372 
373 	if (IS_ERR(rtc))
374 		return PTR_ERR(rtc);
375 
376 	platform_set_drvdata(pdev, rtc);
377 
378 	return 0;
379 }
380 
381 static struct platform_driver rs5c313_rtc_platform_driver = {
382 	.driver         = {
383 		.name   = DRV_NAME,
384 	},
385 	.probe	= rs5c313_rtc_probe,
386 };
387 
388 static int __init rs5c313_rtc_init(void)
389 {
390 	int err;
391 
392 	err = platform_driver_register(&rs5c313_rtc_platform_driver);
393 	if (err)
394 		return err;
395 
396 	rs5c313_init_port();
397 	rs5c313_check_xstp_bit();
398 
399 	return 0;
400 }
401 
402 static void __exit rs5c313_rtc_exit(void)
403 {
404 	platform_driver_unregister(&rs5c313_rtc_platform_driver);
405 }
406 
407 module_init(rs5c313_rtc_init);
408 module_exit(rs5c313_rtc_exit);
409 
410 MODULE_VERSION(DRV_VERSION);
411 MODULE_AUTHOR("kogiidena , Nobuhiro Iwamatsu <iwamatsu@nigauri.org>");
412 MODULE_DESCRIPTION("Ricoh RS5C313 RTC device driver");
413 MODULE_LICENSE("GPL");
414 MODULE_ALIAS("platform:" DRV_NAME);
415