xref: /freebsd/sys/dev/iicbus/iic.c (revision 2546665afcaf0d53dc2c7058fee96354b3680f5a)
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/malloc.h>
33 #include <sys/module.h>
34 #include <sys/bus.h>
35 #include <sys/conf.h>
36 #include <sys/uio.h>
37 #include <sys/fcntl.h>
38 
39 #include <dev/iicbus/iiconf.h>
40 #include <dev/iicbus/iicbus.h>
41 #include <dev/iicbus/iic.h>
42 
43 #include "iicbus_if.h"
44 
45 #define BUFSIZE 1024
46 
47 struct iic_softc {
48 
49 	u_char sc_addr;			/* 7 bit address on iicbus */
50 	int sc_count;			/* >0 if device opened */
51 
52 	char sc_buffer[BUFSIZE];	/* output buffer */
53 	char sc_inbuf[BUFSIZE];		/* input buffer */
54 
55 	struct cdev *sc_devnode;
56 };
57 
58 #define IIC_SOFTC(unit) \
59 	((struct iic_softc *)devclass_get_softc(iic_devclass, (unit)))
60 
61 #define IIC_DEVICE(unit) \
62 	(devclass_get_device(iic_devclass, (unit)))
63 
64 static int iic_probe(device_t);
65 static int iic_attach(device_t);
66 static int iic_detach(device_t);
67 static void iic_identify(driver_t *driver, device_t parent);
68 
69 static devclass_t iic_devclass;
70 
71 static device_method_t iic_methods[] = {
72 	/* device interface */
73 	DEVMETHOD(device_identify,	iic_identify),
74 	DEVMETHOD(device_probe,		iic_probe),
75 	DEVMETHOD(device_attach,	iic_attach),
76 	DEVMETHOD(device_detach,	iic_detach),
77 
78 	/* iicbus interface */
79 	DEVMETHOD(iicbus_intr,		iicbus_generic_intr),
80 
81 	{ 0, 0 }
82 };
83 
84 static driver_t iic_driver = {
85 	"iic",
86 	iic_methods,
87 	sizeof(struct iic_softc),
88 };
89 
90 static	d_open_t	iicopen;
91 static	d_close_t	iicclose;
92 static	d_write_t	iicwrite;
93 static	d_read_t	iicread;
94 static	d_ioctl_t	iicioctl;
95 
96 static struct cdevsw iic_cdevsw = {
97 	.d_version =	D_VERSION,
98 	.d_flags =	D_NEEDGIANT,
99 	.d_open =	iicopen,
100 	.d_close =	iicclose,
101 	.d_read =	iicread,
102 	.d_write =	iicwrite,
103 	.d_ioctl =	iicioctl,
104 	.d_name =	"iic",
105 };
106 
107 static void
108 iic_identify(driver_t *driver, device_t parent)
109 {
110 	BUS_ADD_CHILD(parent, 0, "iic", -1);
111 }
112 
113 static int
114 iic_probe(device_t dev)
115 {
116 	device_set_desc(dev, "I2C generic I/O");
117 	return (0);
118 }
119 
120 static int
121 iic_attach(device_t dev)
122 {
123 	struct iic_softc *sc = (struct iic_softc *)device_get_softc(dev);
124 
125 	if (!sc)
126 		return (ENOMEM);
127 
128 	bzero(sc, sizeof(struct iic_softc));
129 
130 	sc->sc_devnode = make_dev(&iic_cdevsw, device_get_unit(dev),
131 			UID_ROOT, GID_WHEEL,
132 			0600, "iic%d", device_get_unit(dev));
133 
134 	return (0);
135 }
136 
137 static int
138 iic_detach(device_t dev)
139 {
140 	struct iic_softc *sc = (struct iic_softc *)device_get_softc(dev);
141 
142 	if (sc->sc_devnode)
143 		destroy_dev(sc->sc_devnode);
144 
145 	return (0);
146 }
147 
148 static int
149 iicopen (struct cdev *dev, int flags, int fmt, struct thread *td)
150 {
151 	struct iic_softc *sc = IIC_SOFTC(minor(dev));
152 
153 	if (!sc)
154 		return (EINVAL);
155 
156 	if (sc->sc_count > 0)
157 		return (EBUSY);
158 
159 	sc->sc_count++;
160 
161 	return (0);
162 }
163 
164 static int
165 iicclose(struct cdev *dev, int flags, int fmt, struct thread *td)
166 {
167 	struct iic_softc *sc = IIC_SOFTC(minor(dev));
168 
169 	if (!sc)
170 		return (EINVAL);
171 
172 	if (!sc->sc_count)
173 		return (EINVAL);
174 
175 	sc->sc_count--;
176 
177 	if (sc->sc_count < 0)
178 		panic("%s: iic_count < 0!", __func__);
179 
180 	return (0);
181 }
182 
183 static int
184 iicwrite(struct cdev *dev, struct uio * uio, int ioflag)
185 {
186 	device_t iicdev = IIC_DEVICE(minor(dev));
187 	struct iic_softc *sc = IIC_SOFTC(minor(dev));
188 	int sent, error, count;
189 
190 	if (!sc || !iicdev || !sc->sc_addr)
191 		return (EINVAL);
192 
193 	if (sc->sc_count == 0)
194 		return (EINVAL);
195 
196 	if ((error = iicbus_request_bus(device_get_parent(iicdev), iicdev, IIC_DONTWAIT)))
197 		return (error);
198 
199 	count = min(uio->uio_resid, BUFSIZE);
200 	uiomove(sc->sc_buffer, count, uio);
201 
202 	error = iicbus_block_write(device_get_parent(iicdev), sc->sc_addr,
203 					sc->sc_buffer, count, &sent);
204 
205 	iicbus_release_bus(device_get_parent(iicdev), iicdev);
206 
207 	return(error);
208 }
209 
210 static int
211 iicread(struct cdev *dev, struct uio * uio, int ioflag)
212 {
213 	device_t iicdev = IIC_DEVICE(minor(dev));
214 	struct iic_softc *sc = IIC_SOFTC(minor(dev));
215 	int len, error = 0;
216 	int bufsize;
217 
218 	if (!sc || !iicdev || !sc->sc_addr)
219 		return (EINVAL);
220 
221 	if (sc->sc_count == 0)
222 		return (EINVAL);
223 
224 	if ((error = iicbus_request_bus(device_get_parent(iicdev), iicdev, IIC_DONTWAIT)))
225 		return (error);
226 
227 	/* max amount of data to read */
228 	len = min(uio->uio_resid, BUFSIZE);
229 
230 	if ((error = iicbus_block_read(device_get_parent(iicdev), sc->sc_addr,
231 					sc->sc_inbuf, len, &bufsize)))
232 		return (error);
233 
234 	if (bufsize > uio->uio_resid)
235 		panic("%s: too much data read!", __func__);
236 
237 	iicbus_release_bus(device_get_parent(iicdev), iicdev);
238 
239 	return (uiomove(sc->sc_inbuf, bufsize, uio));
240 }
241 
242 static int
243 iicioctl(struct cdev *dev, u_long cmd, caddr_t data, int flags, struct thread *td)
244 {
245 	device_t iicdev = IIC_DEVICE(minor(dev));
246 	struct iic_softc *sc = IIC_SOFTC(minor(dev));
247 	device_t parent = device_get_parent(iicdev);
248 	struct iiccmd *s = (struct iiccmd *)data;
249 	int error, count;
250 	char *buf = NULL;
251 
252 	if (!sc)
253 		return (EINVAL);
254 
255 	if ((error = iicbus_request_bus(device_get_parent(iicdev), iicdev,
256 			(flags & O_NONBLOCK) ? IIC_DONTWAIT :
257 						(IIC_WAIT | IIC_INTR))))
258 		return (error);
259 
260 	switch (cmd) {
261 	case I2CSTART:
262 		error = iicbus_start(parent, s->slave, 0);
263 
264 		/*
265 		 * Implicitly set the chip addr to the slave addr passed as
266 		 * parameter. Consequently, start/stop shall be called before
267 		 * the read or the write of a block.
268 		 */
269 		if (!error)
270 			sc->sc_addr = s->slave;
271 
272 		break;
273 
274 	case I2CSTOP:
275 		error = iicbus_stop(parent);
276 		break;
277 
278 	case I2CRSTCARD:
279 		error = iicbus_reset(parent, 0, 0, NULL);
280 		break;
281 
282 	case I2CWRITE:
283 		if (s->count <= 0) {
284 			error = EINVAL;
285 			break;
286 		}
287 		buf = malloc((unsigned long)s->count, M_TEMP, M_WAITOK);
288 		error = copyin(s->buf, buf, s->count);
289 		if (error)
290 			break;
291 		error = iicbus_write(parent, buf, s->count, &count, 10);
292 		break;
293 
294 	case I2CREAD:
295 		if (s->count <= 0) {
296 			error = EINVAL;
297 			break;
298 		}
299 		buf = malloc((unsigned long)s->count, M_TEMP, M_WAITOK);
300 		error = iicbus_read(parent, buf, s->count, &count, s->last, 10);
301 		if (error)
302 			break;
303 		error = copyout(buf, s->buf, s->count);
304 		break;
305 
306 	default:
307 		error = ENOTTY;
308 	}
309 
310 	iicbus_release_bus(device_get_parent(iicdev), iicdev);
311 
312 	if (buf != NULL)
313 		free(buf, M_TEMP);
314 	return (error);
315 }
316 
317 DRIVER_MODULE(iic, iicbus, iic_driver, iic_devclass, 0, 0);
318 MODULE_DEPEND(iic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
319 MODULE_VERSION(iic, 1);
320