xref: /freebsd/sys/dev/iicbus/iic.c (revision 77a0943ded95b9e6438f7db70c4a28e4d93946d4)
1 /*-
2  * Copyright (c) 1998 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 
39 #include <dev/iicbus/iiconf.h>
40 #include <dev/iicbus/iicbus.h>
41 
42 #include <machine/iic.h>
43 
44 #include "iicbus_if.h"
45 
46 #define BUFSIZE 1024
47 
48 struct iic_softc {
49 
50 	u_char sc_addr;			/* address on iicbus */
51 	int sc_count;			/* >0 if device opened */
52 
53 	char sc_buffer[BUFSIZE];	/* output buffer */
54 	char sc_inbuf[BUFSIZE];		/* input buffer */
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 
66 static devclass_t iic_devclass;
67 
68 static device_method_t iic_methods[] = {
69 	/* device interface */
70 	DEVMETHOD(device_probe,		iic_probe),
71 	DEVMETHOD(device_attach,	iic_attach),
72 
73 	/* iicbus interface */
74 	DEVMETHOD(iicbus_intr,		iicbus_generic_intr),
75 
76 	{ 0, 0 }
77 };
78 
79 static driver_t iic_driver = {
80 	"iic",
81 	iic_methods,
82 	sizeof(struct iic_softc),
83 };
84 
85 static	d_open_t	iicopen;
86 static	d_close_t	iicclose;
87 static	d_write_t	iicwrite;
88 static	d_read_t	iicread;
89 static	d_ioctl_t	iicioctl;
90 
91 #define CDEV_MAJOR 105
92 static struct cdevsw iic_cdevsw = {
93 	/* open */	iicopen,
94 	/* close */	iicclose,
95 	/* read */	iicread,
96 	/* write */	iicwrite,
97 	/* ioctl */	iicioctl,
98 	/* poll */	nopoll,
99 	/* mmap */	nommap,
100 	/* strategy */	nostrategy,
101 	/* name */	"iic",
102 	/* maj */	CDEV_MAJOR,
103 	/* dump */	nodump,
104 	/* psize */	nopsize,
105 	/* flags */	0,
106 	/* bmaj */	-1
107 };
108 
109 /*
110  * iicprobe()
111  */
112 static int
113 iic_probe(device_t dev)
114 {
115 	struct iic_softc *sc = (struct iic_softc *)device_get_softc(dev);
116 
117 	sc->sc_addr = iicbus_get_addr(dev);
118 
119 	/* XXX detect chip with start/stop conditions */
120 
121 	return (0);
122 }
123 
124 /*
125  * iicattach()
126  */
127 static int
128 iic_attach(device_t dev)
129 {
130 	make_dev(&iic_cdevsw, device_get_unit(dev),	/* XXX cleanup */
131 			UID_ROOT, GID_WHEEL,
132 			0600, "iic%d", device_get_unit(dev));
133 	return (0);
134 }
135 
136 static int
137 iicopen (dev_t dev, int flags, int fmt, struct proc *p)
138 {
139 	struct iic_softc *sc = IIC_SOFTC(minor(dev));
140 
141 	if (!sc)
142 		return (EINVAL);
143 
144 	if (sc->sc_count > 0)
145 		return (EBUSY);
146 
147 	sc->sc_count++;
148 
149 	return (0);
150 }
151 
152 static int
153 iicclose(dev_t dev, int flags, int fmt, struct proc *p)
154 {
155 	struct iic_softc *sc = IIC_SOFTC(minor(dev));
156 
157 	if (!sc)
158 		return (EINVAL);
159 
160 	if (!sc->sc_count)
161 		return (EINVAL);
162 
163 	sc->sc_count--;
164 
165 	if (sc->sc_count < 0)
166 		panic("%s: iic_count < 0!", __FUNCTION__);
167 
168 	return (0);
169 }
170 
171 static int
172 iicwrite(dev_t dev, struct uio * uio, int ioflag)
173 {
174 	device_t iicdev = IIC_DEVICE(minor(dev));
175 	struct iic_softc *sc = IIC_SOFTC(minor(dev));
176 	int sent, error, count;
177 
178 	if (!sc || !iicdev)
179 		return (EINVAL);
180 
181 	if (sc->sc_count == 0)
182 		return (EINVAL);
183 
184 	if ((error = iicbus_request_bus(device_get_parent(iicdev), iicdev, IIC_DONTWAIT)))
185 		return (error);
186 
187 	count = min(uio->uio_resid, BUFSIZE);
188 	uiomove(sc->sc_buffer, count, uio);
189 
190 	error = iicbus_block_write(device_get_parent(iicdev), sc->sc_addr,
191 					sc->sc_buffer, count, &sent);
192 
193 	iicbus_release_bus(device_get_parent(iicdev), iicdev);
194 
195 	return(error);
196 }
197 
198 static int
199 iicread(dev_t dev, struct uio * uio, int ioflag)
200 {
201 	device_t iicdev = IIC_DEVICE(minor(dev));
202 	struct iic_softc *sc = IIC_SOFTC(minor(dev));
203 	int len, error = 0;
204 	int bufsize;
205 
206 	if (!sc || !iicdev)
207 		return (EINVAL);
208 
209 	if (sc->sc_count == 0)
210 		return (EINVAL);
211 
212 	if ((error = iicbus_request_bus(device_get_parent(iicdev), iicdev, IIC_DONTWAIT)))
213 		return (error);
214 
215 	/* max amount of data to read */
216 	len = min(uio->uio_resid, BUFSIZE);
217 
218 	if ((error = iicbus_block_read(device_get_parent(iicdev), sc->sc_addr,
219 					sc->sc_inbuf, len, &bufsize)))
220 		return (error);
221 
222 	if (bufsize > uio->uio_resid)
223 		panic("%s: too much data read!", __FUNCTION__);
224 
225 	iicbus_release_bus(device_get_parent(iicdev), iicdev);
226 
227 	return (uiomove(sc->sc_inbuf, bufsize, uio));
228 }
229 
230 static int
231 iicioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct proc *p)
232 {
233 	device_t iicdev = IIC_DEVICE(minor(dev));
234 	struct iic_softc *sc = IIC_SOFTC(minor(dev));
235 	device_t parent = device_get_parent(iicdev);
236 	struct iiccmd *s = (struct iiccmd *)data;
237 	int error, count;
238 
239 	if (!sc)
240 		return (EINVAL);
241 
242 	if ((error = iicbus_request_bus(device_get_parent(iicdev), iicdev,
243 			(flags & O_NONBLOCK) ? IIC_DONTWAIT :
244 						(IIC_WAIT | IIC_INTR))))
245 		return (error);
246 
247 	switch (cmd) {
248 	case I2CSTART:
249 		error = iicbus_start(parent, s->slave, 0);
250 		break;
251 
252 	case I2CSTOP:
253 		error = iicbus_stop(parent);
254 		break;
255 
256 	case I2CRSTCARD:
257 		error = iicbus_reset(parent, 0, 0, NULL);
258 		break;
259 
260 	case I2CWRITE:
261 		error = iicbus_write(parent, s->buf, s->count, &count, 0);
262 		break;
263 
264 	case I2CREAD:
265 		error = iicbus_read(parent, s->buf, s->count, &count, s->last, 0);
266 		break;
267 
268 	default:
269 		error = ENODEV;
270 	}
271 
272 	iicbus_release_bus(device_get_parent(iicdev), iicdev);
273 
274 	return (error);
275 }
276 
277 DRIVER_MODULE(iic, iicbus, iic_driver, iic_devclass, 0, 0);
278