xref: /freebsd/sys/dev/iicbus/iic.c (revision 4c8945a06b01a5c8122cdeb402af36bb46a06acc)
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", -1);
114 }
115 
116 static int
117 iic_probe(device_t dev)
118 {
119 	if (iicbus_get_addr(dev) > 0)
120 		return (ENXIO);
121 
122 	device_set_desc(dev, "I2C generic I/O");
123 
124 	return (0);
125 }
126 
127 static int
128 iic_attach(device_t dev)
129 {
130 	struct iic_softc *sc = (struct iic_softc *)device_get_softc(dev);
131 
132 	sc->sc_dev = dev;
133 	sx_init(&sc->sc_lock, "iic");
134 	sc->sc_devnode = make_dev(&iic_cdevsw, device_get_unit(dev),
135 			UID_ROOT, GID_WHEEL,
136 			0600, "iic%d", device_get_unit(dev));
137 	if (sc->sc_devnode == NULL) {
138 		device_printf(dev, "failed to create character device\n");
139 		sx_destroy(&sc->sc_lock);
140 		return (ENXIO);
141 	}
142 	sc->sc_devnode->si_drv1 = sc;
143 
144 	return (0);
145 }
146 
147 static int
148 iic_detach(device_t dev)
149 {
150 	struct iic_softc *sc = (struct iic_softc *)device_get_softc(dev);
151 
152 	if (sc->sc_devnode)
153 		destroy_dev(sc->sc_devnode);
154 	sx_destroy(&sc->sc_lock);
155 
156 	return (0);
157 }
158 
159 static int
160 iicopen(struct cdev *dev, int flags, int fmt, struct thread *td)
161 {
162 	struct iic_softc *sc = dev->si_drv1;
163 
164 	IIC_LOCK(sc);
165 	if (sc->sc_count > 0) {
166 		IIC_UNLOCK(sc);
167 		return (EBUSY);
168 	}
169 
170 	sc->sc_count++;
171 	IIC_UNLOCK(sc);
172 
173 	return (0);
174 }
175 
176 static int
177 iicclose(struct cdev *dev, int flags, int fmt, struct thread *td)
178 {
179 	struct iic_softc *sc = dev->si_drv1;
180 
181 	IIC_LOCK(sc);
182 	if (!sc->sc_count) {
183 		/* XXX: I don't think this can happen. */
184 		IIC_UNLOCK(sc);
185 		return (EINVAL);
186 	}
187 
188 	sc->sc_count--;
189 
190 	if (sc->sc_count < 0)
191 		panic("%s: iic_count < 0!", __func__);
192 	IIC_UNLOCK(sc);
193 
194 	return (0);
195 }
196 
197 static int
198 iicwrite(struct cdev *dev, struct uio * uio, int ioflag)
199 {
200 	struct iic_softc *sc = dev->si_drv1;
201 	device_t iicdev = sc->sc_dev;
202 	int sent, error, count;
203 
204 	IIC_LOCK(sc);
205 	if (!sc->sc_addr) {
206 		IIC_UNLOCK(sc);
207 		return (EINVAL);
208 	}
209 
210 	if (sc->sc_count == 0) {
211 		/* XXX: I don't think this can happen. */
212 		IIC_UNLOCK(sc);
213 		return (EINVAL);
214 	}
215 
216 	error = iicbus_request_bus(device_get_parent(iicdev), iicdev,
217 	    IIC_DONTWAIT);
218 	if (error) {
219 		IIC_UNLOCK(sc);
220 		return (error);
221 	}
222 
223 	count = min(uio->uio_resid, BUFSIZE);
224 	uiomove(sc->sc_buffer, count, uio);
225 
226 	error = iicbus_block_write(device_get_parent(iicdev), sc->sc_addr,
227 					sc->sc_buffer, count, &sent);
228 
229 	iicbus_release_bus(device_get_parent(iicdev), iicdev);
230 	IIC_UNLOCK(sc);
231 
232 	return (error);
233 }
234 
235 static int
236 iicread(struct cdev *dev, struct uio * uio, int ioflag)
237 {
238 	struct iic_softc *sc = dev->si_drv1;
239 	device_t iicdev = sc->sc_dev;
240 	int len, error = 0;
241 	int bufsize;
242 
243 	IIC_LOCK(sc);
244 	if (!sc->sc_addr) {
245 		IIC_UNLOCK(sc);
246 		return (EINVAL);
247 	}
248 
249 	if (sc->sc_count == 0) {
250 		/* XXX: I don't think this can happen. */
251 		IIC_UNLOCK(sc);
252 		return (EINVAL);
253 	}
254 
255 	error = iicbus_request_bus(device_get_parent(iicdev), iicdev,
256 	    IIC_DONTWAIT);
257 	if (error) {
258 		IIC_UNLOCK(sc);
259 		return (error);
260 	}
261 
262 	/* max amount of data to read */
263 	len = min(uio->uio_resid, BUFSIZE);
264 
265 	error = iicbus_block_read(device_get_parent(iicdev), sc->sc_addr,
266 	    sc->sc_inbuf, len, &bufsize);
267 	if (error) {
268 		IIC_UNLOCK(sc);
269 		return (error);
270 	}
271 
272 	if (bufsize > uio->uio_resid)
273 		panic("%s: too much data read!", __func__);
274 
275 	iicbus_release_bus(device_get_parent(iicdev), iicdev);
276 
277 	error = uiomove(sc->sc_inbuf, bufsize, uio);
278 	IIC_UNLOCK(sc);
279 	return (error);
280 }
281 
282 static int
283 iicioctl(struct cdev *dev, u_long cmd, caddr_t data, int flags, struct thread *td)
284 {
285 	struct iic_softc *sc = dev->si_drv1;
286 	device_t iicdev = sc->sc_dev;
287 	device_t parent = device_get_parent(iicdev);
288 	struct iiccmd *s = (struct iiccmd *)data;
289 	struct iic_rdwr_data *d = (struct iic_rdwr_data *)data;
290 	struct iic_msg *m;
291 	int error, count, i;
292 	char *buf = NULL;
293 	void **usrbufs = NULL;
294 
295 	if ((error = iicbus_request_bus(parent, iicdev,
296 	    (flags & O_NONBLOCK) ? IIC_DONTWAIT : (IIC_WAIT | IIC_INTR))))
297 		return (error);
298 
299 	switch (cmd) {
300 	case I2CSTART:
301 		IIC_LOCK(sc);
302 		error = iicbus_start(parent, s->slave, 0);
303 
304 		/*
305 		 * Implicitly set the chip addr to the slave addr passed as
306 		 * parameter. Consequently, start/stop shall be called before
307 		 * the read or the write of a block.
308 		 */
309 		if (!error)
310 			sc->sc_addr = s->slave;
311 		IIC_UNLOCK(sc);
312 
313 		break;
314 
315 	case I2CSTOP:
316 		error = iicbus_stop(parent);
317 		break;
318 
319 	case I2CRSTCARD:
320 		error = iicbus_reset(parent, IIC_UNKNOWN, 0, NULL);
321 		break;
322 
323 	case I2CWRITE:
324 		if (s->count <= 0) {
325 			error = EINVAL;
326 			break;
327 		}
328 		buf = malloc((unsigned long)s->count, M_TEMP, M_WAITOK);
329 		error = copyin(s->buf, buf, s->count);
330 		if (error)
331 			break;
332 		error = iicbus_write(parent, buf, s->count, &count, 10);
333 		break;
334 
335 	case I2CREAD:
336 		if (s->count <= 0) {
337 			error = EINVAL;
338 			break;
339 		}
340 		buf = malloc((unsigned long)s->count, M_TEMP, M_WAITOK);
341 		error = iicbus_read(parent, buf, s->count, &count, s->last, 10);
342 		if (error)
343 			break;
344 		error = copyout(buf, s->buf, s->count);
345 		break;
346 
347 	case I2CRDWR:
348 		buf = malloc(sizeof(*d->msgs) * d->nmsgs, M_TEMP, M_WAITOK);
349 		usrbufs = malloc(sizeof(void *) * d->nmsgs, M_TEMP, M_ZERO | M_WAITOK);
350 		error = copyin(d->msgs, buf, sizeof(*d->msgs) * d->nmsgs);
351 		if (error)
352 			break;
353 		/* Alloc kernel buffers for userland data, copyin write data */
354 		for (i = 0; i < d->nmsgs; i++) {
355 			m = &((struct iic_msg *)buf)[i];
356 			usrbufs[i] = m->buf;
357 			m->buf = malloc(m->len, M_TEMP, M_WAITOK);
358 			if (!(m->flags & IIC_M_RD))
359 				copyin(usrbufs[i], m->buf, m->len);
360 		}
361 		error = iicbus_transfer(iicdev, (struct iic_msg *)buf, d->nmsgs);
362 		/* Copyout all read segments, free up kernel buffers */
363 		for (i = 0; i < d->nmsgs; i++) {
364 			m = &((struct iic_msg *)buf)[i];
365 			if (m->flags & IIC_M_RD)
366 				copyout(m->buf, usrbufs[i], m->len);
367 			free(m->buf, M_TEMP);
368 		}
369 		free(usrbufs, M_TEMP);
370 		break;
371 
372 	case I2CRPTSTART:
373 		error = iicbus_repeated_start(parent, s->slave, 0);
374 		break;
375 
376 	default:
377 		error = ENOTTY;
378 	}
379 
380 	iicbus_release_bus(parent, iicdev);
381 
382 	if (buf != NULL)
383 		free(buf, M_TEMP);
384 	return (error);
385 }
386 
387 DRIVER_MODULE(iic, iicbus, iic_driver, iic_devclass, 0, 0);
388 MODULE_DEPEND(iic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
389 MODULE_VERSION(iic, 1);
390