xref: /freebsd/sys/dev/iicbus/if_ic.c (revision 2e1417489338b971e5fd599ff48b5f65df9e8d3b)
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 <net/route.h>
53 #include <netinet/in.h>
54 #include <netinet/in_systm.h>
55 #include <netinet/in_var.h>
56 #include <netinet/ip.h>
57 #include <netinet/if_ether.h>
58 
59 #include <net/bpf.h>
60 
61 #include <dev/iicbus/iiconf.h>
62 #include <dev/iicbus/iicbus.h>
63 
64 #include "iicbus_if.h"
65 
66 #define PCF_MASTER_ADDRESS 0xaa
67 
68 #define ICHDRLEN	sizeof(u_int32_t)
69 #define ICMTU		1500		/* default mtu */
70 
71 struct ic_softc {
72 	struct ifnet *ic_ifp;
73 	device_t ic_dev;
74 
75 	u_char ic_addr;			/* peer I2C address */
76 
77 	int ic_flags;
78 
79 	char *ic_obuf;
80 	char *ic_ifbuf;
81 	char *ic_cp;
82 
83 	int ic_xfercnt;
84 
85 	int ic_iferrs;
86 
87 	struct mtx ic_lock;
88 };
89 
90 #define	IC_SENDING		0x0001
91 #define	IC_OBUF_BUSY		0x0002
92 #define	IC_IFBUF_BUSY		0x0004
93 #define	IC_BUFFERS_BUSY		(IC_OBUF_BUSY | IC_IFBUF_BUSY)
94 #define	IC_BUFFER_WAITER	0x0004
95 
96 static devclass_t ic_devclass;
97 
98 static int icprobe(device_t);
99 static int icattach(device_t);
100 
101 static int icioctl(struct ifnet *, u_long, caddr_t);
102 static int icoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
103                struct route *);
104 
105 static int icintr(device_t, int, char *);
106 
107 static device_method_t ic_methods[] = {
108 	/* device interface */
109 	DEVMETHOD(device_probe,		icprobe),
110 	DEVMETHOD(device_attach,	icattach),
111 
112 	/* iicbus interface */
113 	DEVMETHOD(iicbus_intr,		icintr),
114 
115 	{ 0, 0 }
116 };
117 
118 static driver_t ic_driver = {
119 	"ic",
120 	ic_methods,
121 	sizeof(struct ic_softc),
122 };
123 
124 static void
125 ic_alloc_buffers(struct ic_softc *sc, int mtu)
126 {
127 	char *obuf, *ifbuf;
128 
129 	obuf = malloc(mtu + ICHDRLEN, M_DEVBUF, M_WAITOK);
130 	ifbuf = malloc(mtu + ICHDRLEN, M_DEVBUF, M_WAITOK);
131 
132 	mtx_lock(&sc->ic_lock);
133 	while (sc->ic_flags & IC_BUFFERS_BUSY) {
134 		sc->ic_flags |= IC_BUFFER_WAITER;
135 		mtx_sleep(sc, &sc->ic_lock, 0, "icalloc", 0);
136 		sc->ic_flags &= ~IC_BUFFER_WAITER;
137 	}
138 
139 	free(sc->ic_obuf, M_DEVBUF);
140 	free(sc->ic_ifbuf, M_DEVBUF);
141 	sc->ic_obuf = obuf;
142 	sc->ic_ifbuf = ifbuf;
143 	sc->ic_ifp->if_mtu = mtu;
144 	mtx_unlock(&sc->ic_lock);
145 }
146 
147 /*
148  * icprobe()
149  */
150 static int
151 icprobe(device_t dev)
152 {
153 	return (BUS_PROBE_NOWILDCARD);
154 }
155 
156 /*
157  * icattach()
158  */
159 static int
160 icattach(device_t dev)
161 {
162 	struct ic_softc *sc = (struct ic_softc *)device_get_softc(dev);
163 	struct ifnet *ifp;
164 
165 	ifp = sc->ic_ifp = if_alloc(IFT_PARA);
166 	if (ifp == NULL)
167 		return (ENOSPC);
168 
169 	mtx_init(&sc->ic_lock, device_get_nameunit(dev), MTX_NETWORK_LOCK,
170 	    MTX_DEF);
171 	sc->ic_addr = PCF_MASTER_ADDRESS;	/* XXX only PCF masters */
172 	sc->ic_dev = dev;
173 
174 	ifp->if_softc = sc;
175 	if_initname(ifp, device_get_name(dev), device_get_unit(dev));
176 	ifp->if_flags = IFF_SIMPLEX | IFF_POINTOPOINT | IFF_MULTICAST;
177 	ifp->if_ioctl = icioctl;
178 	ifp->if_output = icoutput;
179 	ifp->if_hdrlen = 0;
180 	ifp->if_addrlen = 0;
181 	ifp->if_snd.ifq_maxlen = ifqmaxlen;
182 
183 	ic_alloc_buffers(sc, ICMTU);
184 
185 	if_attach(ifp);
186 
187 	bpfattach(ifp, DLT_NULL, ICHDRLEN);
188 
189 	return (0);
190 }
191 
192 /*
193  * iciotcl()
194  */
195 static int
196 icioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
197 {
198 	struct ic_softc *sc = ifp->if_softc;
199 	device_t icdev = sc->ic_dev;
200 	device_t parent = device_get_parent(icdev);
201 	struct ifaddr *ifa = (struct ifaddr *)data;
202 	struct ifreq *ifr = (struct ifreq *)data;
203 	int error;
204 
205 	switch (cmd) {
206 
207 	case SIOCSIFDSTADDR:
208 	case SIOCAIFADDR:
209 	case SIOCSIFADDR:
210 		if (ifa->ifa_addr->sa_family != AF_INET)
211 			return (EAFNOSUPPORT);
212 		mtx_lock(&sc->ic_lock);
213 		ifp->if_flags |= IFF_UP;
214 		goto locked;
215 	case SIOCSIFFLAGS:
216 		mtx_lock(&sc->ic_lock);
217 	locked:
218 		if ((!(ifp->if_flags & IFF_UP)) &&
219 		    (ifp->if_drv_flags & IFF_DRV_RUNNING)) {
220 
221 			/* XXX disable PCF */
222 			ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
223 			mtx_unlock(&sc->ic_lock);
224 
225 			/* IFF_UP is not set, try to release the bus anyway */
226 			iicbus_release_bus(parent, icdev);
227 			break;
228 		}
229 		if (((ifp->if_flags & IFF_UP)) &&
230 		    (!(ifp->if_drv_flags & IFF_DRV_RUNNING))) {
231 			mtx_unlock(&sc->ic_lock);
232 			if ((error = iicbus_request_bus(parent, icdev,
233 			    IIC_WAIT | IIC_INTR)))
234 				return (error);
235 			mtx_lock(&sc->ic_lock);
236 			iicbus_reset(parent, IIC_FASTEST, 0, NULL);
237 			ifp->if_drv_flags |= IFF_DRV_RUNNING;
238 		}
239 		mtx_unlock(&sc->ic_lock);
240 		break;
241 
242 	case SIOCSIFMTU:
243 		ic_alloc_buffers(sc, ifr->ifr_mtu);
244 		break;
245 
246 	case SIOCGIFMTU:
247 		mtx_lock(&sc->ic_lock);
248 		ifr->ifr_mtu = sc->ic_ifp->if_mtu;
249 		mtx_unlock(&sc->ic_lock);
250 		break;
251 
252 	case SIOCADDMULTI:
253 	case SIOCDELMULTI:
254 		if (ifr == 0)
255 			return (EAFNOSUPPORT);		/* XXX */
256 		switch (ifr->ifr_addr.sa_family) {
257 		case AF_INET:
258 			break;
259 		default:
260 			return (EAFNOSUPPORT);
261 		}
262 		break;
263 	default:
264 		return (EINVAL);
265 	}
266 	return (0);
267 }
268 
269 /*
270  * icintr()
271  */
272 static int
273 icintr(device_t dev, int event, char *ptr)
274 {
275 	struct ic_softc *sc = (struct ic_softc *)device_get_softc(dev);
276 	struct mbuf *top;
277 	int len;
278 
279 	mtx_lock(&sc->ic_lock);
280 
281 	switch (event) {
282 
283 	case INTR_GENERAL:
284 	case INTR_START:
285 		sc->ic_cp = sc->ic_ifbuf;
286 		sc->ic_xfercnt = 0;
287 		sc->ic_flags |= IC_IFBUF_BUSY;
288 		break;
289 
290 	case INTR_STOP:
291 
292 		/* if any error occured during transfert,
293 		 * drop the packet */
294 		sc->ic_flags &= ~IC_IFBUF_BUSY;
295 		if ((sc->ic_flags & (IC_BUFFERS_BUSY | IC_BUFFER_WAITER)) ==
296 		    IC_BUFFER_WAITER)
297 			wakeup(&sc);
298 		if (sc->ic_iferrs)
299 			goto err;
300 		if ((len = sc->ic_xfercnt) == 0)
301 			break;					/* ignore */
302 		if (len <= ICHDRLEN)
303 			goto err;
304 		len -= ICHDRLEN;
305 		sc->ic_ifp->if_ipackets++;
306 		sc->ic_ifp->if_ibytes += len;
307 		BPF_TAP(sc->ic_ifp, sc->ic_ifbuf, len + ICHDRLEN);
308 		top = m_devget(sc->ic_ifbuf + ICHDRLEN, len, 0, sc->ic_ifp, 0);
309 		if (top) {
310 			mtx_unlock(&sc->ic_lock);
311 			M_SETFIB(top, sc->ic_ifp->if_fib);
312 			netisr_dispatch(NETISR_IP, top);
313 			mtx_lock(&sc->ic_lock);
314 		}
315 		break;
316 	err:
317 		if_printf(sc->ic_ifp, "errors (%d)!\n", sc->ic_iferrs);
318 		sc->ic_iferrs = 0;			/* reset error count */
319 		sc->ic_ifp->if_ierrors++;
320 		break;
321 
322 	case INTR_RECEIVE:
323 		if (sc->ic_xfercnt >= sc->ic_ifp->if_mtu + ICHDRLEN) {
324 			sc->ic_iferrs++;
325 		} else {
326 			*sc->ic_cp++ = *ptr;
327 			sc->ic_xfercnt++;
328 		}
329 		break;
330 
331 	case INTR_NOACK:			/* xfer terminated by master */
332 		break;
333 
334 	case INTR_TRANSMIT:
335 		*ptr = 0xff;					/* XXX */
336 	  	break;
337 
338 	case INTR_ERROR:
339 		sc->ic_iferrs++;
340 		break;
341 
342 	default:
343 		panic("%s: unknown event (%d)!", __func__, event);
344 	}
345 
346 	mtx_unlock(&sc->ic_lock);
347 	return (0);
348 }
349 
350 /*
351  * icoutput()
352  */
353 static int
354 icoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
355     struct route *ro)
356 {
357 	struct ic_softc *sc = ifp->if_softc;
358 	device_t icdev = sc->ic_dev;
359 	device_t parent = device_get_parent(icdev);
360 	int len, sent;
361 	struct mbuf *mm;
362 	u_char *cp;
363 	u_int32_t hdr;
364 
365 	/* BPF writes need to be handled specially. */
366 	if (dst->sa_family == AF_UNSPEC)
367 		bcopy(dst->sa_data, &hdr, sizeof(hdr));
368 	else
369 		hdr = dst->sa_family;
370 
371 	mtx_lock(&sc->ic_lock);
372 	ifp->if_drv_flags |= IFF_DRV_RUNNING;
373 
374 	/* already sending? */
375 	if (sc->ic_flags & IC_SENDING) {
376 		ifp->if_oerrors++;
377 		goto error;
378 	}
379 
380 	/* insert header */
381 	bcopy ((char *)&hdr, sc->ic_obuf, ICHDRLEN);
382 
383 	cp = sc->ic_obuf + ICHDRLEN;
384 	len = 0;
385 	mm = m;
386 	do {
387 		if (len + mm->m_len > sc->ic_ifp->if_mtu) {
388 			/* packet too large */
389 			ifp->if_oerrors++;
390 			goto error;
391 		}
392 
393 		bcopy(mtod(mm,char *), cp, mm->m_len);
394 		cp += mm->m_len;
395 		len += mm->m_len;
396 
397 	} while ((mm = mm->m_next));
398 
399 	BPF_MTAP2(ifp, &hdr, sizeof(hdr), m);
400 
401 	sc->ic_flags |= (IC_SENDING | IC_OBUF_BUSY);
402 
403 	m_freem(m);
404 	mtx_unlock(&sc->ic_lock);
405 
406 	/* send the packet */
407 	if (iicbus_block_write(parent, sc->ic_addr, sc->ic_obuf,
408 				len + ICHDRLEN, &sent))
409 
410 		ifp->if_oerrors++;
411 	else {
412 		ifp->if_opackets++;
413 		ifp->if_obytes += len;
414 	}
415 
416 	mtx_lock(&sc->ic_lock);
417 	sc->ic_flags &= ~(IC_SENDING | IC_OBUF_BUSY);
418 	if ((sc->ic_flags & (IC_BUFFERS_BUSY | IC_BUFFER_WAITER)) ==
419 	    IC_BUFFER_WAITER)
420 		wakeup(&sc);
421 	mtx_unlock(&sc->ic_lock);
422 
423 	return (0);
424 
425 error:
426 	m_freem(m);
427 	mtx_unlock(&sc->ic_lock);
428 
429 	return(0);
430 }
431 
432 DRIVER_MODULE(ic, iicbus, ic_driver, ic_devclass, 0, 0);
433 MODULE_DEPEND(ic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
434 MODULE_VERSION(ic, 1);
435