if_ic.c revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 1998, 2001 Nicolas Souchu
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD: stable/11/sys/dev/iicbus/if_ic.c 330897 2018-03-14 03:19:51Z eadler $");
31
32/*
33 * I2C bus IP driver
34 */
35
36#include <sys/param.h>
37#include <sys/systm.h>
38#include <sys/mbuf.h>
39#include <sys/socket.h>
40#include <sys/filio.h>
41#include <sys/sockio.h>
42#include <sys/kernel.h>
43#include <sys/lock.h>
44#include <sys/module.h>
45#include <sys/mutex.h>
46#include <sys/bus.h>
47#include <sys/time.h>
48#include <sys/malloc.h>
49
50#include <net/if.h>
51#include <net/if_var.h>
52#include <net/if_types.h>
53#include <net/netisr.h>
54
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 *, const 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 SIOCAIFADDR:
211	case SIOCSIFADDR:
212		if (ifa->ifa_addr->sa_family != AF_INET)
213			return (EAFNOSUPPORT);
214		mtx_lock(&sc->ic_lock);
215		ifp->if_flags |= IFF_UP;
216		goto locked;
217	case SIOCSIFFLAGS:
218		mtx_lock(&sc->ic_lock);
219	locked:
220		if ((!(ifp->if_flags & IFF_UP)) &&
221		    (ifp->if_drv_flags & IFF_DRV_RUNNING)) {
222
223			/* XXX disable PCF */
224			ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
225			mtx_unlock(&sc->ic_lock);
226
227			/* IFF_UP is not set, try to release the bus anyway */
228			iicbus_release_bus(parent, icdev);
229			break;
230		}
231		if (((ifp->if_flags & IFF_UP)) &&
232		    (!(ifp->if_drv_flags & IFF_DRV_RUNNING))) {
233			mtx_unlock(&sc->ic_lock);
234			if ((error = iicbus_request_bus(parent, icdev,
235			    IIC_WAIT | IIC_INTR)))
236				return (error);
237			mtx_lock(&sc->ic_lock);
238			iicbus_reset(parent, IIC_FASTEST, 0, NULL);
239			ifp->if_drv_flags |= IFF_DRV_RUNNING;
240		}
241		mtx_unlock(&sc->ic_lock);
242		break;
243
244	case SIOCSIFMTU:
245		ic_alloc_buffers(sc, ifr->ifr_mtu);
246		break;
247
248	case SIOCGIFMTU:
249		mtx_lock(&sc->ic_lock);
250		ifr->ifr_mtu = sc->ic_ifp->if_mtu;
251		mtx_unlock(&sc->ic_lock);
252		break;
253
254	case SIOCADDMULTI:
255	case SIOCDELMULTI:
256		if (ifr == NULL)
257			return (EAFNOSUPPORT);		/* XXX */
258		switch (ifr->ifr_addr.sa_family) {
259		case AF_INET:
260			break;
261		default:
262			return (EAFNOSUPPORT);
263		}
264		break;
265	default:
266		return (EINVAL);
267	}
268	return (0);
269}
270
271/*
272 * icintr()
273 */
274static int
275icintr(device_t dev, int event, char *ptr)
276{
277	struct ic_softc *sc = (struct ic_softc *)device_get_softc(dev);
278	struct mbuf *top;
279	int len;
280
281	mtx_lock(&sc->ic_lock);
282
283	switch (event) {
284
285	case INTR_GENERAL:
286	case INTR_START:
287		sc->ic_cp = sc->ic_ifbuf;
288		sc->ic_xfercnt = 0;
289		sc->ic_flags |= IC_IFBUF_BUSY;
290		break;
291
292	case INTR_STOP:
293
294		/* if any error occurred during transfert,
295		 * drop the packet */
296		sc->ic_flags &= ~IC_IFBUF_BUSY;
297		if ((sc->ic_flags & (IC_BUFFERS_BUSY | IC_BUFFER_WAITER)) ==
298		    IC_BUFFER_WAITER)
299			wakeup(&sc);
300		if (sc->ic_iferrs)
301			goto err;
302		if ((len = sc->ic_xfercnt) == 0)
303			break;					/* ignore */
304		if (len <= ICHDRLEN)
305			goto err;
306		len -= ICHDRLEN;
307		if_inc_counter(sc->ic_ifp, IFCOUNTER_IPACKETS, 1);
308		if_inc_counter(sc->ic_ifp, IFCOUNTER_IBYTES, len);
309		BPF_TAP(sc->ic_ifp, sc->ic_ifbuf, len + ICHDRLEN);
310		top = m_devget(sc->ic_ifbuf + ICHDRLEN, len, 0, sc->ic_ifp, 0);
311		if (top) {
312			mtx_unlock(&sc->ic_lock);
313			M_SETFIB(top, sc->ic_ifp->if_fib);
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		if_inc_counter(sc->ic_ifp, IFCOUNTER_IERRORS, 1);
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, const 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		if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
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			if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
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		if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
413	else {
414		if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
415		if_inc_counter(ifp, IFCOUNTER_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