xref: /openbsd-src/sys/dev/i2c/pcf8523.c (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c)
1 /*	$OpenBSD: pcf8523.c,v 1.3 2016/05/20 20:33:53 kettenis Exp $	*/
2 
3 /*
4  * Copyright (c) 2005 Kimihiro Nonaka
5  * Copyright (c) 2016 Mark Kettenis
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
19  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
21  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27  * POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/device.h>
33 #include <sys/kernel.h>
34 #include <sys/fcntl.h>
35 #include <sys/uio.h>
36 #include <sys/conf.h>
37 #include <sys/event.h>
38 
39 #include <dev/clock_subr.h>
40 
41 #include <dev/i2c/i2cvar.h>
42 
43 /*
44  * PCF8523 Real-Time Clock
45  */
46 
47 #define	PCF8523_ADDR		0x68	/* Fixed I2C Slave Address */
48 
49 #define PCF8523_CONTROL1	0x00
50 #define PCF8523_CONTROL2	0x01
51 #define PCF8523_CONTROL3	0x02
52 #define PCF8523_SECONDS		0x03
53 #define PCF8523_MINUTES		0x04
54 #define PCF8523_HOURS		0x05
55 #define PCF8523_DAY		0x06
56 #define PCF8523_WDAY		0x07
57 #define PCF8523_MONTH		0x08
58 #define PCF8523_YEAR		0x09
59 #define PCF8523_ALARM_MIN	0x0a
60 #define PCF8523_ALARM_HOUR	0x0b
61 #define PCF8523_ALARM_DAY	0x0c
62 #define PCF8523_ALARM_WDAY	0x0d
63 #define PCF8523_OFFSET		0x0e
64 
65 #define	PCF8523_NREGS		20
66 #define	PCF8523_NRTC_REGS	7
67 
68 /*
69  * Bit definitions.
70  */
71 #define	PCF8523_CONTROL1_12_24	(1 << 3)
72 #define	PCF8523_CONTROL1_STOP	(1 << 5)
73 #define	PCF8523_CONTROL3_PM_MASK 0xe0
74 #define PCF8523_CONTROL3_PM_BLD	(1 << 7)
75 #define PCF8523_CONTROL3_PM_VDD	(1 << 6)
76 #define PCF8523_CONTROL3_PM_DSM	(1 << 5)
77 #define PCF8523_CONTROL3_BLF	(1 << 2)
78 #define	PCF8523_SECONDS_MASK	0x7f
79 #define	PCF8523_SECONDS_OS	(1 << 7)
80 #define	PCF8523_MINUTES_MASK	0x7f
81 #define	PCF8523_HOURS_12HRS_PM	(1 << 5)	/* If 12 hr mode, set = PM */
82 #define	PCF8523_HOURS_12MASK	0x1f
83 #define	PCF8523_HOURS_24MASK	0x3f
84 #define	PCF8523_DAY_MASK	0x3f
85 #define	PCF8523_WDAY_MASK	0x07
86 #define	PCF8523_MONTH_MASK	0x1f
87 
88 struct pcfrtc_softc {
89 	struct device sc_dev;
90 	i2c_tag_t sc_tag;
91 	int sc_address;
92 	struct todr_chip_handle sc_todr;
93 };
94 
95 int pcfrtc_match(struct device *, void *, void *);
96 void pcfrtc_attach(struct device *, struct device *, void *);
97 
98 struct cfattach pcfrtc_ca = {
99 	sizeof(struct pcfrtc_softc), pcfrtc_match, pcfrtc_attach
100 };
101 
102 struct cfdriver pcfrtc_cd = {
103 	NULL, "pcfrtc", DV_DULL
104 };
105 
106 uint8_t pcfrtc_reg_read(struct pcfrtc_softc *, int);
107 void pcfrtc_reg_write(struct pcfrtc_softc *, int, uint8_t);
108 int pcfrtc_clock_read(struct pcfrtc_softc *, struct clock_ymdhms *);
109 int pcfrtc_clock_write(struct pcfrtc_softc *, struct clock_ymdhms *);
110 int pcfrtc_gettime(struct todr_chip_handle *, struct timeval *);
111 int pcfrtc_settime(struct todr_chip_handle *, struct timeval *);
112 int pcfrtc_getcal(struct todr_chip_handle *, int *);
113 int pcfrtc_setcal(struct todr_chip_handle *, int);
114 
115 int
116 pcfrtc_match(struct device *parent, void *v, void *arg)
117 {
118 	struct i2c_attach_args *ia = arg;
119 
120 	if (strcmp(ia->ia_name, "nxp,pcf8523") == 0 &&
121 	    ia->ia_addr == PCF8523_ADDR)
122 		return (1);
123 
124 	return (0);
125 }
126 
127 void
128 pcfrtc_attach(struct device *parent, struct device *self, void *arg)
129 {
130 	struct pcfrtc_softc *sc = (struct pcfrtc_softc *)self;
131 	struct i2c_attach_args *ia = arg;
132 	uint8_t reg;
133 
134 	sc->sc_tag = ia->ia_tag;
135 	sc->sc_address = ia->ia_addr;
136 	sc->sc_todr.cookie = sc;
137 	sc->sc_todr.todr_gettime = pcfrtc_gettime;
138 	sc->sc_todr.todr_settime = pcfrtc_settime;
139 	sc->sc_todr.todr_getcal = pcfrtc_getcal;
140 	sc->sc_todr.todr_setcal = pcfrtc_setcal;
141 	sc->sc_todr.todr_setwen = NULL;
142 
143 #if 0
144 	todr_attach(&sc->sc_todr);
145 #else
146 	/* XXX */
147 	{
148 	extern todr_chip_handle_t todr_handle;
149 	todr_handle = &sc->sc_todr;
150 	}
151 #endif
152 
153 	/*
154 	 * Enable battery switch-over and battery low detection in
155 	 * standard mode, and switch to 24 hour mode.
156 	 */
157 	reg = pcfrtc_reg_read(sc, PCF8523_CONTROL3);
158 	reg &= ~PCF8523_CONTROL3_PM_MASK;
159 	pcfrtc_reg_write(sc, PCF8523_CONTROL3, reg);
160 	reg = pcfrtc_reg_read(sc, PCF8523_CONTROL1);
161 	reg &= ~PCF8523_CONTROL1_12_24;
162 	reg &= ~PCF8523_CONTROL1_STOP;
163 	pcfrtc_reg_write(sc, PCF8523_CONTROL1, reg);
164 
165 	/* Report battery status. */
166 	reg = pcfrtc_reg_read(sc, PCF8523_CONTROL3);
167 	printf(": battery %s\n", (reg & PCF8523_CONTROL3_BLF) ? "low" : "ok");
168 
169 	/* Clear OS flag.  */
170 	reg = pcfrtc_reg_read(sc, PCF8523_SECONDS);
171 	if (reg & PCF8523_SECONDS_OS) {
172 		reg &= ~PCF8523_SECONDS_OS;
173 		pcfrtc_reg_write(sc, PCF8523_SECONDS, reg);
174 	}
175 }
176 
177 int
178 pcfrtc_gettime(struct todr_chip_handle *ch, struct timeval *tv)
179 {
180 	struct pcfrtc_softc *sc = ch->cookie;
181 	struct clock_ymdhms dt;
182 
183 	memset(&dt, 0, sizeof(dt));
184 	if (pcfrtc_clock_read(sc, &dt) == 0)
185 		return (-1);
186 
187 	tv->tv_sec = clock_ymdhms_to_secs(&dt);
188 	tv->tv_usec = 0;
189 	return (0);
190 }
191 
192 int
193 pcfrtc_settime(struct todr_chip_handle *ch, struct timeval *tv)
194 {
195 	struct pcfrtc_softc *sc = ch->cookie;
196 	struct clock_ymdhms dt;
197 
198 	clock_secs_to_ymdhms(tv->tv_sec, &dt);
199 
200 	if (pcfrtc_clock_write(sc, &dt) == 0)
201 		return (-1);
202 	return (0);
203 }
204 
205 int
206 pcfrtc_setcal(struct todr_chip_handle *ch, int cal)
207 {
208 	return (EOPNOTSUPP);
209 }
210 
211 int
212 pcfrtc_getcal(struct todr_chip_handle *ch, int *cal)
213 {
214 	return (EOPNOTSUPP);
215 }
216 
217 uint8_t
218 pcfrtc_reg_read(struct pcfrtc_softc *sc, int reg)
219 {
220 	uint8_t cmd = reg;
221 	uint8_t val;
222 
223 	iic_acquire_bus(sc->sc_tag, I2C_F_POLL);
224 	if (iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_address,
225 	    NULL, 0, &cmd, sizeof cmd, I2C_F_POLL) ||
226 	    iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_address,
227 	    NULL, 0, &val, sizeof val, I2C_F_POLL)) {
228 		iic_release_bus(sc->sc_tag, I2C_F_POLL);
229 		printf("%s: pcfrtc_reg_read: failed to read reg%d\n",
230 		    sc->sc_dev.dv_xname, reg);
231 		return 0;
232 	}
233 	iic_release_bus(sc->sc_tag, I2C_F_POLL);
234 	return val;
235 }
236 
237 void
238 pcfrtc_reg_write(struct pcfrtc_softc *sc, int reg, uint8_t val)
239 {
240 	uint8_t cmd = reg;
241 
242 	iic_acquire_bus(sc->sc_tag, I2C_F_POLL);
243 	if (iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_address,
244 	    &cmd, sizeof cmd, &val, sizeof val, I2C_F_POLL)) {
245 		iic_release_bus(sc->sc_tag, I2C_F_POLL);
246 		printf("%s: pcfrtc_reg_write: failed to write reg%d\n",
247 		    sc->sc_dev.dv_xname, reg);
248 		return;
249 	}
250 	iic_release_bus(sc->sc_tag, I2C_F_POLL);
251 }
252 
253 int
254 pcfrtc_clock_read(struct pcfrtc_softc *sc, struct clock_ymdhms *dt)
255 {
256 	uint8_t regs[PCF8523_NRTC_REGS];
257 	uint8_t cmd = PCF8523_SECONDS;
258 
259 	iic_acquire_bus(sc->sc_tag, I2C_F_POLL);
260 	if (iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_address,
261 	    NULL, 0, &cmd, sizeof cmd, I2C_F_POLL) ||
262 	    iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_address,
263 	    NULL, 0, regs, PCF8523_NRTC_REGS, I2C_F_POLL)) {
264 		iic_release_bus(sc->sc_tag, I2C_F_POLL);
265 		printf("%s: pcfrtc_clock_read: failed to read rtc\n",
266 		    sc->sc_dev.dv_xname);
267 		return (0);
268 	}
269 	iic_release_bus(sc->sc_tag, I2C_F_POLL);
270 
271 	/*
272 	 * Convert the PCF8523's register values into something useable
273 	 */
274 	dt->dt_sec = FROMBCD(regs[0] & PCF8523_SECONDS_MASK);
275 	dt->dt_min = FROMBCD(regs[1] & PCF8523_MINUTES_MASK);
276 	dt->dt_hour = FROMBCD(regs[2] & PCF8523_HOURS_24MASK);
277 	dt->dt_day = FROMBCD(regs[3] & PCF8523_DAY_MASK);
278 	dt->dt_mon = FROMBCD(regs[5] & PCF8523_MONTH_MASK);
279 	dt->dt_year = FROMBCD(regs[6]) + 2000;
280 
281 	if ((regs[0] & PCF8523_SECONDS_OS))
282 		return (0);
283 
284 	return (1);
285 }
286 
287 int
288 pcfrtc_clock_write(struct pcfrtc_softc *sc, struct clock_ymdhms *dt)
289 {
290 	uint8_t regs[PCF8523_NRTC_REGS];
291 	uint8_t cmd = PCF8523_SECONDS;
292 
293 	/*
294 	 * Convert our time representation into something the PCF8523
295 	 * can understand.
296 	 */
297 	regs[0] = TOBCD(dt->dt_sec);
298 	regs[1] = TOBCD(dt->dt_min);
299 	regs[2] = TOBCD(dt->dt_hour);
300 	regs[3] = TOBCD(dt->dt_day);
301 	regs[4] = TOBCD(dt->dt_wday);
302 	regs[5] = TOBCD(dt->dt_mon);
303 	regs[6] = TOBCD(dt->dt_year - 2000);
304 
305 	iic_acquire_bus(sc->sc_tag, I2C_F_POLL);
306 	if (iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_address,
307 	    &cmd, sizeof cmd, regs, PCF8523_NRTC_REGS, I2C_F_POLL)) {
308 		iic_release_bus(sc->sc_tag, I2C_F_POLL);
309 		printf("%s: pcfrtc_clock_write: failed to write rtc\n",
310 		    sc->sc_dev.dv_xname);
311 		return (0);
312 	}
313 	iic_release_bus(sc->sc_tag, I2C_F_POLL);
314 	return (1);
315 }
316