xref: /freebsd/sys/dev/iicbus/iic.c (revision 6780ab54325a71e7e70112b11657973edde8655e)
1 /*-
2  * Copyright (c) 1998, 2001 Nicolas Souchu
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  *
28  */
29 #include <sys/param.h>
30 #include <sys/kernel.h>
31 #include <sys/systm.h>
32 #include <sys/module.h>
33 #include <sys/bus.h>
34 #include <sys/conf.h>
35 #include <sys/uio.h>
36 #include <sys/fcntl.h>
37 
38 #include <dev/iicbus/iiconf.h>
39 #include <dev/iicbus/iicbus.h>
40 #include <dev/iicbus/iic.h>
41 
42 #include "iicbus_if.h"
43 
44 #define BUFSIZE 1024
45 
46 struct iic_softc {
47 
48 	u_char sc_addr;			/* 7 bit address on iicbus */
49 	int sc_count;			/* >0 if device opened */
50 
51 	char sc_buffer[BUFSIZE];	/* output buffer */
52 	char sc_inbuf[BUFSIZE];		/* input buffer */
53 
54 	dev_t sc_devnode;
55 };
56 
57 #define IIC_SOFTC(unit) \
58 	((struct iic_softc *)devclass_get_softc(iic_devclass, (unit)))
59 
60 #define IIC_DEVICE(unit) \
61 	(devclass_get_device(iic_devclass, (unit)))
62 
63 static int iic_probe(device_t);
64 static int iic_attach(device_t);
65 static int iic_detach(device_t);
66 static void iic_identify(driver_t *driver, device_t parent);
67 
68 static devclass_t iic_devclass;
69 
70 static device_method_t iic_methods[] = {
71 	/* device interface */
72 	DEVMETHOD(device_identify,	iic_identify),
73 	DEVMETHOD(device_probe,		iic_probe),
74 	DEVMETHOD(device_attach,	iic_attach),
75 	DEVMETHOD(device_detach,	iic_detach),
76 
77 	/* iicbus interface */
78 	DEVMETHOD(iicbus_intr,		iicbus_generic_intr),
79 
80 	{ 0, 0 }
81 };
82 
83 static driver_t iic_driver = {
84 	"iic",
85 	iic_methods,
86 	sizeof(struct iic_softc),
87 };
88 
89 static	d_open_t	iicopen;
90 static	d_close_t	iicclose;
91 static	d_write_t	iicwrite;
92 static	d_read_t	iicread;
93 static	d_ioctl_t	iicioctl;
94 
95 #define CDEV_MAJOR 105
96 static struct cdevsw iic_cdevsw = {
97 	/* open */	iicopen,
98 	/* close */	iicclose,
99 	/* read */	iicread,
100 	/* write */	iicwrite,
101 	/* ioctl */	iicioctl,
102 	/* poll */	nopoll,
103 	/* mmap */	nommap,
104 	/* strategy */	nostrategy,
105 	/* name */	"iic",
106 	/* maj */	CDEV_MAJOR,
107 	/* dump */	nodump,
108 	/* psize */	nopsize,
109 	/* flags */	0,
110 };
111 
112 static void
113 iic_identify(driver_t *driver, device_t parent)
114 {
115 	BUS_ADD_CHILD(parent, 0, "iic", 0);
116 }
117 
118 static int
119 iic_probe(device_t dev)
120 {
121 	device_set_desc(dev, "I2C generic I/O");
122 	return (0);
123 }
124 
125 static int
126 iic_attach(device_t dev)
127 {
128 	struct iic_softc *sc = (struct iic_softc *)device_get_softc(dev);
129 
130 	if (!sc)
131 		return (ENOMEM);
132 
133 	bzero(sc, sizeof(struct iic_softc));
134 
135 	sc->sc_devnode = make_dev(&iic_cdevsw, device_get_unit(dev),
136 			UID_ROOT, GID_WHEEL,
137 			0600, "iic%d", device_get_unit(dev));
138 
139 	return (0);
140 }
141 
142 static int
143 iic_detach(device_t dev)
144 {
145 	struct iic_softc *sc = (struct iic_softc *)device_get_softc(dev);
146 
147 	if (sc->sc_devnode)
148 		destroy_dev(sc->sc_devnode);
149 
150 	return (0);
151 }
152 
153 static int
154 iicopen (dev_t dev, int flags, int fmt, struct thread *td)
155 {
156 	struct iic_softc *sc = IIC_SOFTC(minor(dev));
157 
158 	if (!sc)
159 		return (EINVAL);
160 
161 	if (sc->sc_count > 0)
162 		return (EBUSY);
163 
164 	sc->sc_count++;
165 
166 	return (0);
167 }
168 
169 static int
170 iicclose(dev_t dev, int flags, int fmt, struct thread *td)
171 {
172 	struct iic_softc *sc = IIC_SOFTC(minor(dev));
173 
174 	if (!sc)
175 		return (EINVAL);
176 
177 	if (!sc->sc_count)
178 		return (EINVAL);
179 
180 	sc->sc_count--;
181 
182 	if (sc->sc_count < 0)
183 		panic("%s: iic_count < 0!", __func__);
184 
185 	return (0);
186 }
187 
188 static int
189 iicwrite(dev_t dev, struct uio * uio, int ioflag)
190 {
191 	device_t iicdev = IIC_DEVICE(minor(dev));
192 	struct iic_softc *sc = IIC_SOFTC(minor(dev));
193 	int sent, error, count;
194 
195 	if (!sc || !iicdev || !sc->sc_addr)
196 		return (EINVAL);
197 
198 	if (sc->sc_count == 0)
199 		return (EINVAL);
200 
201 	if ((error = iicbus_request_bus(device_get_parent(iicdev), iicdev, IIC_DONTWAIT)))
202 		return (error);
203 
204 	count = min(uio->uio_resid, BUFSIZE);
205 	uiomove(sc->sc_buffer, count, uio);
206 
207 	error = iicbus_block_write(device_get_parent(iicdev), sc->sc_addr,
208 					sc->sc_buffer, count, &sent);
209 
210 	iicbus_release_bus(device_get_parent(iicdev), iicdev);
211 
212 	return(error);
213 }
214 
215 static int
216 iicread(dev_t dev, struct uio * uio, int ioflag)
217 {
218 	device_t iicdev = IIC_DEVICE(minor(dev));
219 	struct iic_softc *sc = IIC_SOFTC(minor(dev));
220 	int len, error = 0;
221 	int bufsize;
222 
223 	if (!sc || !iicdev || !sc->sc_addr)
224 		return (EINVAL);
225 
226 	if (sc->sc_count == 0)
227 		return (EINVAL);
228 
229 	if ((error = iicbus_request_bus(device_get_parent(iicdev), iicdev, IIC_DONTWAIT)))
230 		return (error);
231 
232 	/* max amount of data to read */
233 	len = min(uio->uio_resid, BUFSIZE);
234 
235 	if ((error = iicbus_block_read(device_get_parent(iicdev), sc->sc_addr,
236 					sc->sc_inbuf, len, &bufsize)))
237 		return (error);
238 
239 	if (bufsize > uio->uio_resid)
240 		panic("%s: too much data read!", __func__);
241 
242 	iicbus_release_bus(device_get_parent(iicdev), iicdev);
243 
244 	return (uiomove(sc->sc_inbuf, bufsize, uio));
245 }
246 
247 static int
248 iicioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct thread *td)
249 {
250 	device_t iicdev = IIC_DEVICE(minor(dev));
251 	struct iic_softc *sc = IIC_SOFTC(minor(dev));
252 	device_t parent = device_get_parent(iicdev);
253 	struct iiccmd *s = (struct iiccmd *)data;
254 	int error, count;
255 
256 	if (!sc)
257 		return (EINVAL);
258 
259 	if ((error = iicbus_request_bus(device_get_parent(iicdev), iicdev,
260 			(flags & O_NONBLOCK) ? IIC_DONTWAIT :
261 						(IIC_WAIT | IIC_INTR))))
262 		return (error);
263 
264 	switch (cmd) {
265 	case I2CSTART:
266 		error = iicbus_start(parent, s->slave, 0);
267 
268 		/*
269 		 * Implicitly set the chip addr to the slave addr passed as
270 		 * parameter. Consequently, start/stop shall be called before
271 		 * the read or the write of a block.
272 		 */
273 		if (!error)
274 			sc->sc_addr = s->slave;
275 
276 		break;
277 
278 	case I2CSTOP:
279 		error = iicbus_stop(parent);
280 		break;
281 
282 	case I2CRSTCARD:
283 		error = iicbus_reset(parent, 0, 0, NULL);
284 		break;
285 
286 	case I2CWRITE:
287 		error = iicbus_write(parent, s->buf, s->count, &count, 10);
288 		break;
289 
290 	case I2CREAD:
291 		error = iicbus_read(parent, s->buf, s->count, &count, s->last, 10);
292 		break;
293 
294 	default:
295 		error = ENODEV;
296 	}
297 
298 	iicbus_release_bus(device_get_parent(iicdev), iicdev);
299 
300 	return (error);
301 }
302 
303 DRIVER_MODULE(iic, iicbus, iic_driver, iic_devclass, 0, 0);
304 MODULE_DEPEND(iic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
305 MODULE_VERSION(iic, 1);
306