if_ic.c revision 207554 
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: head/sys/dev/iicbus/if_ic.c 207554 2010-05-03 07:32:50Z sobomax $");
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
74struct 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
99static devclass_t ic_devclass;
100
101static int icprobe(device_t);
102static int icattach(device_t);
103
104static int icioctl(struct ifnet *, u_long, caddr_t);
105static int icoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
106               struct route *);
107
108static int icintr(device_t, int, char *);
109
110static 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
121static driver_t ic_driver = {
122	"ic",
123	ic_methods,
124	sizeof(struct ic_softc),
125};
126
127static void
128ic_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 */
153static int
154icprobe(device_t dev)
155{
156	return (BUS_PROBE_NOWILDCARD);
157}
158
159/*
160 * icattach()
161 */
162static int
163icattach(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 = ifqmaxlen;
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 */
198static int
199icioctl(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 */
275static int
276icintr(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 */
355static int
356icoutput(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
427error:
428	m_freem(m);
429	mtx_unlock(&sc->ic_lock);
430
431	return(0);
432}
433
434DRIVER_MODULE(ic, iicbus, ic_driver, ic_devclass, 0, 0);
435MODULE_DEPEND(ic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
436MODULE_VERSION(ic, 1);
437