xref: /freebsd/sys/dev/iicbus/iic.c (revision 9162f64b58d01ec01481d60b6cdc06ffd8e8c7fc)
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/bus.h>
31 #include <sys/conf.h>
32 #include <sys/fcntl.h>
33 #include <sys/lock.h>
34 #include <sys/kernel.h>
35 #include <sys/malloc.h>
36 #include <sys/module.h>
37 #include <sys/sx.h>
38 #include <sys/systm.h>
39 #include <sys/uio.h>
40 
41 #include <dev/iicbus/iiconf.h>
42 #include <dev/iicbus/iicbus.h>
43 #include <dev/iicbus/iic.h>
44 
45 #include "iicbus_if.h"
46 
47 #define BUFSIZE 1024
48 
49 struct iic_softc {
50 
51 	device_t sc_dev;
52 	u_char sc_addr;			/* 7 bit address on iicbus */
53 	int sc_count;			/* >0 if device opened */
54 
55 	char sc_buffer[BUFSIZE];	/* output buffer */
56 	char sc_inbuf[BUFSIZE];		/* input buffer */
57 
58 	struct cdev *sc_devnode;
59 	struct sx sc_lock;
60 };
61 
62 #define	IIC_LOCK(sc)			sx_xlock(&(sc)->sc_lock)
63 #define	IIC_UNLOCK(sc)			sx_xunlock(&(sc)->sc_lock)
64 
65 static int iic_probe(device_t);
66 static int iic_attach(device_t);
67 static int iic_detach(device_t);
68 static void iic_identify(driver_t *driver, device_t parent);
69 
70 static devclass_t iic_devclass;
71 
72 static device_method_t iic_methods[] = {
73 	/* device interface */
74 	DEVMETHOD(device_identify,	iic_identify),
75 	DEVMETHOD(device_probe,		iic_probe),
76 	DEVMETHOD(device_attach,	iic_attach),
77 	DEVMETHOD(device_detach,	iic_detach),
78 
79 	/* iicbus interface */
80 	DEVMETHOD(iicbus_intr,		iicbus_generic_intr),
81 
82 	{ 0, 0 }
83 };
84 
85 static driver_t iic_driver = {
86 	"iic",
87 	iic_methods,
88 	sizeof(struct iic_softc),
89 };
90 
91 static	d_open_t	iicopen;
92 static	d_close_t	iicclose;
93 static	d_write_t	iicwrite;
94 static	d_read_t	iicread;
95 static	d_ioctl_t	iicioctl;
96 
97 static struct cdevsw iic_cdevsw = {
98 	.d_version =	D_VERSION,
99 	.d_flags =	D_TRACKCLOSE,
100 	.d_open =	iicopen,
101 	.d_close =	iicclose,
102 	.d_read =	iicread,
103 	.d_write =	iicwrite,
104 	.d_ioctl =	iicioctl,
105 	.d_name =	"iic",
106 };
107 
108 static void
109 iic_identify(driver_t *driver, device_t parent)
110 {
111 
112 	if (device_find_child(parent, "iic", -1) == NULL)
113 		BUS_ADD_CHILD(parent, 0, "iic", 0);
114 }
115 
116 static int
117 iic_probe(device_t dev)
118 {
119 	device_set_desc(dev, "I2C generic I/O");
120 	return (BUS_PROBE_NOWILDCARD);
121 }
122 
123 static int
124 iic_attach(device_t dev)
125 {
126 	struct iic_softc *sc = (struct iic_softc *)device_get_softc(dev);
127 
128 	sc->sc_dev = dev;
129 	sx_init(&sc->sc_lock, "iic");
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 	if (sc->sc_devnode == NULL) {
134 		device_printf(dev, "failed to create character device\n");
135 		sx_destroy(&sc->sc_lock);
136 		return (ENXIO);
137 	}
138 	sc->sc_devnode->si_drv1 = sc;
139 
140 	return (0);
141 }
142 
143 static int
144 iic_detach(device_t dev)
145 {
146 	struct iic_softc *sc = (struct iic_softc *)device_get_softc(dev);
147 
148 	if (sc->sc_devnode)
149 		destroy_dev(sc->sc_devnode);
150 	sx_destroy(&sc->sc_lock);
151 
152 	return (0);
153 }
154 
155 static int
156 iicopen(struct cdev *dev, int flags, int fmt, struct thread *td)
157 {
158 	struct iic_softc *sc = dev->si_drv1;
159 
160 	IIC_LOCK(sc);
161 	if (sc->sc_count > 0) {
162 		IIC_UNLOCK(sc);
163 		return (EBUSY);
164 	}
165 
166 	sc->sc_count++;
167 	IIC_UNLOCK(sc);
168 
169 	return (0);
170 }
171 
172 static int
173 iicclose(struct cdev *dev, int flags, int fmt, struct thread *td)
174 {
175 	struct iic_softc *sc = dev->si_drv1;
176 
177 	IIC_LOCK(sc);
178 	if (!sc->sc_count) {
179 		/* XXX: I don't think this can happen. */
180 		IIC_UNLOCK(sc);
181 		return (EINVAL);
182 	}
183 
184 	sc->sc_count--;
185 
186 	if (sc->sc_count < 0)
187 		panic("%s: iic_count < 0!", __func__);
188 	IIC_UNLOCK(sc);
189 
190 	return (0);
191 }
192 
193 static int
194 iicwrite(struct cdev *dev, struct uio * uio, int ioflag)
195 {
196 	struct iic_softc *sc = dev->si_drv1;
197 	device_t iicdev = sc->sc_dev;
198 	int sent, error, count;
199 
200 	IIC_LOCK(sc);
201 	if (!sc->sc_addr) {
202 		IIC_UNLOCK(sc);
203 		return (EINVAL);
204 	}
205 
206 	if (sc->sc_count == 0) {
207 		/* XXX: I don't think this can happen. */
208 		IIC_UNLOCK(sc);
209 		return (EINVAL);
210 	}
211 
212 	error = iicbus_request_bus(device_get_parent(iicdev), iicdev,
213 	    IIC_DONTWAIT);
214 	if (error) {
215 		IIC_UNLOCK(sc);
216 		return (error);
217 	}
218 
219 	count = min(uio->uio_resid, BUFSIZE);
220 	uiomove(sc->sc_buffer, count, uio);
221 
222 	error = iicbus_block_write(device_get_parent(iicdev), sc->sc_addr,
223 					sc->sc_buffer, count, &sent);
224 
225 	iicbus_release_bus(device_get_parent(iicdev), iicdev);
226 	IIC_UNLOCK(sc);
227 
228 	return (error);
229 }
230 
231 static int
232 iicread(struct cdev *dev, struct uio * uio, int ioflag)
233 {
234 	struct iic_softc *sc = dev->si_drv1;
235 	device_t iicdev = sc->sc_dev;
236 	int len, error = 0;
237 	int bufsize;
238 
239 	IIC_LOCK(sc);
240 	if (!sc->sc_addr) {
241 		IIC_UNLOCK(sc);
242 		return (EINVAL);
243 	}
244 
245 	if (sc->sc_count == 0) {
246 		/* XXX: I don't think this can happen. */
247 		IIC_UNLOCK(sc);
248 		return (EINVAL);
249 	}
250 
251 	error = iicbus_request_bus(device_get_parent(iicdev), iicdev,
252 	    IIC_DONTWAIT);
253 	if (error) {
254 		IIC_UNLOCK(sc);
255 		return (error);
256 	}
257 
258 	/* max amount of data to read */
259 	len = min(uio->uio_resid, BUFSIZE);
260 
261 	error = iicbus_block_read(device_get_parent(iicdev), sc->sc_addr,
262 	    sc->sc_inbuf, len, &bufsize);
263 	if (error) {
264 		IIC_UNLOCK(sc);
265 		return (error);
266 	}
267 
268 	if (bufsize > uio->uio_resid)
269 		panic("%s: too much data read!", __func__);
270 
271 	iicbus_release_bus(device_get_parent(iicdev), iicdev);
272 
273 	error = uiomove(sc->sc_inbuf, bufsize, uio);
274 	IIC_UNLOCK(sc);
275 	return (error);
276 }
277 
278 static int
279 iicioctl(struct cdev *dev, u_long cmd, caddr_t data, int flags, struct thread *td)
280 {
281 	struct iic_softc *sc = dev->si_drv1;
282 	device_t iicdev = sc->sc_dev;
283 	device_t parent = device_get_parent(iicdev);
284 	struct iiccmd *s = (struct iiccmd *)data;
285 	struct iic_rdwr_data *d = (struct iic_rdwr_data *)data;
286 	struct iic_msg *m;
287 	int error, count, i;
288 	char *buf = NULL;
289 	void **usrbufs = NULL;
290 
291 	if ((error = iicbus_request_bus(parent, iicdev,
292 	    (flags & O_NONBLOCK) ? IIC_DONTWAIT : (IIC_WAIT | IIC_INTR))))
293 		return (error);
294 
295 	switch (cmd) {
296 	case I2CSTART:
297 		IIC_LOCK(sc);
298 		error = iicbus_start(parent, s->slave, 0);
299 
300 		/*
301 		 * Implicitly set the chip addr to the slave addr passed as
302 		 * parameter. Consequently, start/stop shall be called before
303 		 * the read or the write of a block.
304 		 */
305 		if (!error)
306 			sc->sc_addr = s->slave;
307 		IIC_UNLOCK(sc);
308 
309 		break;
310 
311 	case I2CSTOP:
312 		error = iicbus_stop(parent);
313 		break;
314 
315 	case I2CRSTCARD:
316 		error = iicbus_reset(parent, IIC_UNKNOWN, 0, NULL);
317 		break;
318 
319 	case I2CWRITE:
320 		if (s->count <= 0) {
321 			error = EINVAL;
322 			break;
323 		}
324 		buf = malloc((unsigned long)s->count, M_TEMP, M_WAITOK);
325 		error = copyin(s->buf, buf, s->count);
326 		if (error)
327 			break;
328 		error = iicbus_write(parent, buf, s->count, &count, 10);
329 		break;
330 
331 	case I2CREAD:
332 		if (s->count <= 0) {
333 			error = EINVAL;
334 			break;
335 		}
336 		buf = malloc((unsigned long)s->count, M_TEMP, M_WAITOK);
337 		error = iicbus_read(parent, buf, s->count, &count, s->last, 10);
338 		if (error)
339 			break;
340 		error = copyout(buf, s->buf, s->count);
341 		break;
342 
343 	case I2CRDWR:
344 		buf = malloc(sizeof(*d->msgs) * d->nmsgs, M_TEMP, M_WAITOK);
345 		usrbufs = malloc(sizeof(void *) * d->nmsgs, M_TEMP, M_ZERO | M_WAITOK);
346 		error = copyin(d->msgs, buf, sizeof(*d->msgs) * d->nmsgs);
347 		if (error)
348 			break;
349 		/* Alloc kernel buffers for userland data, copyin write data */
350 		for (i = 0; i < d->nmsgs; i++) {
351 			m = &((struct iic_msg *)buf)[i];
352 			usrbufs[i] = m->buf;
353 			m->buf = malloc(m->len, M_TEMP, M_WAITOK);
354 			if (!(m->flags & IIC_M_RD))
355 				copyin(usrbufs[i], m->buf, m->len);
356 		}
357 		error = iicbus_transfer(iicdev, (struct iic_msg *)buf, d->nmsgs);
358 		/* Copyout all read segments, free up kernel buffers */
359 		for (i = 0; i < d->nmsgs; i++) {
360 			m = &((struct iic_msg *)buf)[i];
361 			if (m->flags & IIC_M_RD)
362 				copyout(m->buf, usrbufs[i], m->len);
363 			free(m->buf, M_TEMP);
364 		}
365 		free(usrbufs, M_TEMP);
366 		break;
367 	default:
368 		error = ENOTTY;
369 	}
370 
371 	iicbus_release_bus(parent, iicdev);
372 
373 	if (buf != NULL)
374 		free(buf, M_TEMP);
375 	return (error);
376 }
377 
378 DRIVER_MODULE(iic, iicbus, iic_driver, iic_devclass, 0, 0);
379 MODULE_DEPEND(iic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
380 MODULE_VERSION(iic, 1);
381