xref: /freebsd/sys/dev/iicbus/if_ic.c (revision 0a36787e4c1fa0cf77dcf83be0867178476e372b)
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("$FreeBSD$");
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 
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 *, const 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 = 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  */
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 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  */
274 static int
275 icintr(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 			struct epoch_tracker et;
313 
314 			mtx_unlock(&sc->ic_lock);
315 			M_SETFIB(top, sc->ic_ifp->if_fib);
316 			NET_EPOCH_ENTER(et);
317 			netisr_dispatch(NETISR_IP, top);
318 			NET_EPOCH_EXIT(et);
319 			mtx_lock(&sc->ic_lock);
320 		}
321 		break;
322 	err:
323 		if_printf(sc->ic_ifp, "errors (%d)!\n", sc->ic_iferrs);
324 		sc->ic_iferrs = 0;			/* reset error count */
325 		if_inc_counter(sc->ic_ifp, IFCOUNTER_IERRORS, 1);
326 		break;
327 
328 	case INTR_RECEIVE:
329 		if (sc->ic_xfercnt >= sc->ic_ifp->if_mtu + ICHDRLEN) {
330 			sc->ic_iferrs++;
331 		} else {
332 			*sc->ic_cp++ = *ptr;
333 			sc->ic_xfercnt++;
334 		}
335 		break;
336 
337 	case INTR_NOACK:			/* xfer terminated by master */
338 		break;
339 
340 	case INTR_TRANSMIT:
341 		*ptr = 0xff;					/* XXX */
342 	  	break;
343 
344 	case INTR_ERROR:
345 		sc->ic_iferrs++;
346 		break;
347 
348 	default:
349 		panic("%s: unknown event (%d)!", __func__, event);
350 	}
351 
352 	mtx_unlock(&sc->ic_lock);
353 	return (0);
354 }
355 
356 /*
357  * icoutput()
358  */
359 static int
360 icoutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
361     struct route *ro)
362 {
363 	struct ic_softc *sc = ifp->if_softc;
364 	device_t icdev = sc->ic_dev;
365 	device_t parent = device_get_parent(icdev);
366 	int len, sent;
367 	struct mbuf *mm;
368 	u_char *cp;
369 	u_int32_t hdr;
370 
371 	/* BPF writes need to be handled specially. */
372 	if (dst->sa_family == AF_UNSPEC)
373 		bcopy(dst->sa_data, &hdr, sizeof(hdr));
374 	else
375 		hdr = dst->sa_family;
376 
377 	mtx_lock(&sc->ic_lock);
378 	ifp->if_drv_flags |= IFF_DRV_RUNNING;
379 
380 	/* already sending? */
381 	if (sc->ic_flags & IC_SENDING) {
382 		if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
383 		goto error;
384 	}
385 
386 	/* insert header */
387 	bcopy ((char *)&hdr, sc->ic_obuf, ICHDRLEN);
388 
389 	cp = sc->ic_obuf + ICHDRLEN;
390 	len = 0;
391 	mm = m;
392 	do {
393 		if (len + mm->m_len > sc->ic_ifp->if_mtu) {
394 			/* packet too large */
395 			if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
396 			goto error;
397 		}
398 
399 		bcopy(mtod(mm,char *), cp, mm->m_len);
400 		cp += mm->m_len;
401 		len += mm->m_len;
402 
403 	} while ((mm = mm->m_next));
404 
405 	BPF_MTAP2(ifp, &hdr, sizeof(hdr), m);
406 
407 	sc->ic_flags |= (IC_SENDING | IC_OBUF_BUSY);
408 
409 	m_freem(m);
410 	mtx_unlock(&sc->ic_lock);
411 
412 	/* send the packet */
413 	if (iicbus_block_write(parent, sc->ic_addr, sc->ic_obuf,
414 				len + ICHDRLEN, &sent))
415 
416 		if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
417 	else {
418 		if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
419 		if_inc_counter(ifp, IFCOUNTER_OBYTES, len);
420 	}
421 
422 	mtx_lock(&sc->ic_lock);
423 	sc->ic_flags &= ~(IC_SENDING | IC_OBUF_BUSY);
424 	if ((sc->ic_flags & (IC_BUFFERS_BUSY | IC_BUFFER_WAITER)) ==
425 	    IC_BUFFER_WAITER)
426 		wakeup(&sc);
427 	mtx_unlock(&sc->ic_lock);
428 
429 	return (0);
430 
431 error:
432 	m_freem(m);
433 	mtx_unlock(&sc->ic_lock);
434 
435 	return(0);
436 }
437 
438 DRIVER_MODULE(ic, iicbus, ic_driver, ic_devclass, 0, 0);
439 MODULE_DEPEND(ic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
440 MODULE_VERSION(ic, 1);
441