xref: /freebsd/sys/dev/iicbus/if_ic.c (revision 5861f9665471e98e544f6fa3ce73c4912229ff82)
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 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 /*
31  * I2C bus IP driver
32  */
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/mbuf.h>
37 #include <sys/socket.h>
38 #include <sys/filio.h>
39 #include <sys/sockio.h>
40 #include <sys/kernel.h>
41 #include <sys/lock.h>
42 #include <sys/module.h>
43 #include <sys/mutex.h>
44 #include <sys/bus.h>
45 #include <sys/time.h>
46 #include <sys/malloc.h>
47 
48 #include <net/if.h>
49 #include <net/if_types.h>
50 #include <net/netisr.h>
51 
52 #include <sys/mbuf.h>
53 #include <sys/socket.h>
54 #include <net/netisr.h>
55 #include <net/route.h>
56 #include <netinet/in.h>
57 #include <netinet/in_systm.h>
58 #include <netinet/in_var.h>
59 #include <netinet/ip.h>
60 #include <netinet/if_ether.h>
61 
62 #include <net/bpf.h>
63 
64 #include <dev/iicbus/iiconf.h>
65 #include <dev/iicbus/iicbus.h>
66 
67 #include "iicbus_if.h"
68 
69 #define PCF_MASTER_ADDRESS 0xaa
70 
71 #define ICHDRLEN	sizeof(u_int32_t)
72 #define ICMTU		1500		/* default mtu */
73 
74 struct ic_softc {
75 	struct ifnet *ic_ifp;
76 	device_t ic_dev;
77 
78 	u_char ic_addr;			/* peer I2C address */
79 
80 	int ic_flags;
81 
82 	char *ic_obuf;
83 	char *ic_ifbuf;
84 	char *ic_cp;
85 
86 	int ic_xfercnt;
87 
88 	int ic_iferrs;
89 
90 	struct mtx ic_lock;
91 };
92 
93 #define	IC_SENDING		0x0001
94 #define	IC_OBUF_BUSY		0x0002
95 #define	IC_IFBUF_BUSY		0x0004
96 #define	IC_BUFFERS_BUSY		(IC_OBUF_BUSY | IC_IFBUF_BUSY)
97 #define	IC_BUFFER_WAITER	0x0004
98 
99 static devclass_t ic_devclass;
100 
101 static int icprobe(device_t);
102 static int icattach(device_t);
103 
104 static int icioctl(struct ifnet *, u_long, caddr_t);
105 static int icoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
106                struct route *);
107 
108 static int icintr(device_t, int, char *);
109 
110 static device_method_t ic_methods[] = {
111 	/* device interface */
112 	DEVMETHOD(device_probe,		icprobe),
113 	DEVMETHOD(device_attach,	icattach),
114 
115 	/* iicbus interface */
116 	DEVMETHOD(iicbus_intr,		icintr),
117 
118 	{ 0, 0 }
119 };
120 
121 static driver_t ic_driver = {
122 	"ic",
123 	ic_methods,
124 	sizeof(struct ic_softc),
125 };
126 
127 static void
128 ic_alloc_buffers(struct ic_softc *sc, int mtu)
129 {
130 	char *obuf, *ifbuf;
131 
132 	obuf = malloc(mtu + ICHDRLEN, M_DEVBUF, M_WAITOK);
133 	ifbuf = malloc(mtu + ICHDRLEN, M_DEVBUF, M_WAITOK);
134 
135 	mtx_lock(&sc->ic_lock);
136 	while (sc->ic_flags & IC_BUFFERS_BUSY) {
137 		sc->ic_flags |= IC_BUFFER_WAITER;
138 		mtx_sleep(sc, &sc->ic_lock, 0, "icalloc", 0);
139 		sc->ic_flags &= ~IC_BUFFER_WAITER;
140 	}
141 
142 	free(sc->ic_obuf, M_DEVBUF);
143 	free(sc->ic_ifbuf, M_DEVBUF);
144 	sc->ic_obuf = obuf;
145 	sc->ic_ifbuf = ifbuf;
146 	sc->ic_ifp->if_mtu = mtu;
147 	mtx_unlock(&sc->ic_lock);
148 }
149 
150 /*
151  * icprobe()
152  */
153 static int
154 icprobe(device_t dev)
155 {
156 	return (BUS_PROBE_NOWILDCARD);
157 }
158 
159 /*
160  * icattach()
161  */
162 static int
163 icattach(device_t dev)
164 {
165 	struct ic_softc *sc = (struct ic_softc *)device_get_softc(dev);
166 	struct ifnet *ifp;
167 
168 	ifp = sc->ic_ifp = if_alloc(IFT_PARA);
169 	if (ifp == NULL)
170 		return (ENOSPC);
171 
172 	mtx_init(&sc->ic_lock, device_get_nameunit(dev), MTX_NETWORK_LOCK,
173 	    MTX_DEF);
174 	sc->ic_addr = PCF_MASTER_ADDRESS;	/* XXX only PCF masters */
175 	sc->ic_dev = dev;
176 
177 	ifp->if_softc = sc;
178 	if_initname(ifp, device_get_name(dev), device_get_unit(dev));
179 	ifp->if_flags = IFF_SIMPLEX | IFF_POINTOPOINT | IFF_MULTICAST;
180 	ifp->if_ioctl = icioctl;
181 	ifp->if_output = icoutput;
182 	ifp->if_hdrlen = 0;
183 	ifp->if_addrlen = 0;
184 	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
185 
186 	ic_alloc_buffers(sc, ICMTU);
187 
188 	if_attach(ifp);
189 
190 	bpfattach(ifp, DLT_NULL, ICHDRLEN);
191 
192 	return (0);
193 }
194 
195 /*
196  * iciotcl()
197  */
198 static int
199 icioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
200 {
201 	struct ic_softc *sc = ifp->if_softc;
202 	device_t icdev = sc->ic_dev;
203 	device_t parent = device_get_parent(icdev);
204 	struct ifaddr *ifa = (struct ifaddr *)data;
205 	struct ifreq *ifr = (struct ifreq *)data;
206 	int error;
207 
208 	switch (cmd) {
209 
210 	case SIOCSIFDSTADDR:
211 	case SIOCAIFADDR:
212 	case SIOCSIFADDR:
213 		if (ifa->ifa_addr->sa_family != AF_INET)
214 			return (EAFNOSUPPORT);
215 		mtx_lock(&sc->ic_lock);
216 		ifp->if_flags |= IFF_UP;
217 		goto locked;
218 	case SIOCSIFFLAGS:
219 		mtx_lock(&sc->ic_lock);
220 	locked:
221 		if ((!(ifp->if_flags & IFF_UP)) &&
222 		    (ifp->if_drv_flags & IFF_DRV_RUNNING)) {
223 
224 			/* XXX disable PCF */
225 			ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
226 			mtx_unlock(&sc->ic_lock);
227 
228 			/* IFF_UP is not set, try to release the bus anyway */
229 			iicbus_release_bus(parent, icdev);
230 			break;
231 		}
232 		if (((ifp->if_flags & IFF_UP)) &&
233 		    (!(ifp->if_drv_flags & IFF_DRV_RUNNING))) {
234 			mtx_unlock(&sc->ic_lock);
235 			if ((error = iicbus_request_bus(parent, icdev,
236 			    IIC_WAIT | IIC_INTR)))
237 				return (error);
238 			mtx_lock(&sc->ic_lock);
239 			iicbus_reset(parent, IIC_FASTEST, 0, NULL);
240 			ifp->if_drv_flags |= IFF_DRV_RUNNING;
241 		}
242 		mtx_unlock(&sc->ic_lock);
243 		break;
244 
245 	case SIOCSIFMTU:
246 		ic_alloc_buffers(sc, ifr->ifr_mtu);
247 		break;
248 
249 	case SIOCGIFMTU:
250 		mtx_lock(&sc->ic_lock);
251 		ifr->ifr_mtu = sc->ic_ifp->if_mtu;
252 		mtx_unlock(&sc->ic_lock);
253 		break;
254 
255 	case SIOCADDMULTI:
256 	case SIOCDELMULTI:
257 		if (ifr == 0)
258 			return (EAFNOSUPPORT);		/* XXX */
259 		switch (ifr->ifr_addr.sa_family) {
260 		case AF_INET:
261 			break;
262 		default:
263 			return (EAFNOSUPPORT);
264 		}
265 		break;
266 	default:
267 		return (EINVAL);
268 	}
269 	return (0);
270 }
271 
272 /*
273  * icintr()
274  */
275 static int
276 icintr(device_t dev, int event, char *ptr)
277 {
278 	struct ic_softc *sc = (struct ic_softc *)device_get_softc(dev);
279 	struct mbuf *top;
280 	int len;
281 
282 	mtx_lock(&sc->ic_lock);
283 
284 	switch (event) {
285 
286 	case INTR_GENERAL:
287 	case INTR_START:
288 		sc->ic_cp = sc->ic_ifbuf;
289 		sc->ic_xfercnt = 0;
290 		sc->ic_flags |= IC_IFBUF_BUSY;
291 		break;
292 
293 	case INTR_STOP:
294 
295 		/* if any error occured during transfert,
296 		 * drop the packet */
297 		sc->ic_flags &= ~IC_IFBUF_BUSY;
298 		if ((sc->ic_flags & (IC_BUFFERS_BUSY | IC_BUFFER_WAITER)) ==
299 		    IC_BUFFER_WAITER)
300 			wakeup(&sc);
301 		if (sc->ic_iferrs)
302 			goto err;
303 		if ((len = sc->ic_xfercnt) == 0)
304 			break;					/* ignore */
305 		if (len <= ICHDRLEN)
306 			goto err;
307 		len -= ICHDRLEN;
308 		sc->ic_ifp->if_ipackets++;
309 		sc->ic_ifp->if_ibytes += len;
310 		BPF_TAP(sc->ic_ifp, sc->ic_ifbuf, len + ICHDRLEN);
311 		top = m_devget(sc->ic_ifbuf + ICHDRLEN, len, 0, sc->ic_ifp, 0);
312 		if (top) {
313 			mtx_unlock(&sc->ic_lock);
314 			netisr_dispatch(NETISR_IP, top);
315 			mtx_lock(&sc->ic_lock);
316 		}
317 		break;
318 	err:
319 		if_printf(sc->ic_ifp, "errors (%d)!\n", sc->ic_iferrs);
320 		sc->ic_iferrs = 0;			/* reset error count */
321 		sc->ic_ifp->if_ierrors++;
322 		break;
323 
324 	case INTR_RECEIVE:
325 		if (sc->ic_xfercnt >= sc->ic_ifp->if_mtu + ICHDRLEN) {
326 			sc->ic_iferrs++;
327 		} else {
328 			*sc->ic_cp++ = *ptr;
329 			sc->ic_xfercnt++;
330 		}
331 		break;
332 
333 	case INTR_NOACK:			/* xfer terminated by master */
334 		break;
335 
336 	case INTR_TRANSMIT:
337 		*ptr = 0xff;					/* XXX */
338 	  	break;
339 
340 	case INTR_ERROR:
341 		sc->ic_iferrs++;
342 		break;
343 
344 	default:
345 		panic("%s: unknown event (%d)!", __func__, event);
346 	}
347 
348 	mtx_unlock(&sc->ic_lock);
349 	return (0);
350 }
351 
352 /*
353  * icoutput()
354  */
355 static int
356 icoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
357     struct route *ro)
358 {
359 	struct ic_softc *sc = ifp->if_softc;
360 	device_t icdev = sc->ic_dev;
361 	device_t parent = device_get_parent(icdev);
362 	int len, sent;
363 	struct mbuf *mm;
364 	u_char *cp;
365 	u_int32_t hdr;
366 
367 	/* BPF writes need to be handled specially. */
368 	if (dst->sa_family == AF_UNSPEC)
369 		bcopy(dst->sa_data, &hdr, sizeof(hdr));
370 	else
371 		hdr = dst->sa_family;
372 
373 	mtx_lock(&sc->ic_lock);
374 	ifp->if_drv_flags |= IFF_DRV_RUNNING;
375 
376 	/* already sending? */
377 	if (sc->ic_flags & IC_SENDING) {
378 		ifp->if_oerrors++;
379 		goto error;
380 	}
381 
382 	/* insert header */
383 	bcopy ((char *)&hdr, sc->ic_obuf, ICHDRLEN);
384 
385 	cp = sc->ic_obuf + ICHDRLEN;
386 	len = 0;
387 	mm = m;
388 	do {
389 		if (len + mm->m_len > sc->ic_ifp->if_mtu) {
390 			/* packet too large */
391 			ifp->if_oerrors++;
392 			goto error;
393 		}
394 
395 		bcopy(mtod(mm,char *), cp, mm->m_len);
396 		cp += mm->m_len;
397 		len += mm->m_len;
398 
399 	} while ((mm = mm->m_next));
400 
401 	BPF_MTAP2(ifp, &hdr, sizeof(hdr), m);
402 
403 	sc->ic_flags |= (IC_SENDING | IC_OBUF_BUSY);
404 
405 	m_freem(m);
406 	mtx_unlock(&sc->ic_lock);
407 
408 	/* send the packet */
409 	if (iicbus_block_write(parent, sc->ic_addr, sc->ic_obuf,
410 				len + ICHDRLEN, &sent))
411 
412 		ifp->if_oerrors++;
413 	else {
414 		ifp->if_opackets++;
415 		ifp->if_obytes += len;
416 	}
417 
418 	mtx_lock(&sc->ic_lock);
419 	sc->ic_flags &= ~(IC_SENDING | IC_OBUF_BUSY);
420 	if ((sc->ic_flags & (IC_BUFFERS_BUSY | IC_BUFFER_WAITER)) ==
421 	    IC_BUFFER_WAITER)
422 		wakeup(&sc);
423 	mtx_unlock(&sc->ic_lock);
424 
425 	return (0);
426 
427 error:
428 	m_freem(m);
429 	mtx_unlock(&sc->ic_lock);
430 
431 	return(0);
432 }
433 
434 DRIVER_MODULE(ic, iicbus, ic_driver, ic_devclass, 0, 0);
435 MODULE_DEPEND(ic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
436 MODULE_VERSION(ic, 1);
437