xref: /freebsd/sys/dev/iicbus/if_ic.c (revision 716fd348e01c5f2ba125f878a634a753436c2994)
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 int icprobe(device_t);
100 static int icattach(device_t);
101 
102 static int icioctl(struct ifnet *, u_long, caddr_t);
103 static int icoutput(struct ifnet *, struct mbuf *, const struct sockaddr *,
104                struct route *);
105 
106 static int icintr(device_t, int, char *);
107 
108 static device_method_t ic_methods[] = {
109 	/* device interface */
110 	DEVMETHOD(device_probe,		icprobe),
111 	DEVMETHOD(device_attach,	icattach),
112 
113 	/* iicbus interface */
114 	DEVMETHOD(iicbus_intr,		icintr),
115 
116 	{ 0, 0 }
117 };
118 
119 static driver_t ic_driver = {
120 	"ic",
121 	ic_methods,
122 	sizeof(struct ic_softc),
123 };
124 
125 static void
126 ic_alloc_buffers(struct ic_softc *sc, int mtu)
127 {
128 	char *obuf, *ifbuf;
129 
130 	obuf = malloc(mtu + ICHDRLEN, M_DEVBUF, M_WAITOK);
131 	ifbuf = malloc(mtu + ICHDRLEN, M_DEVBUF, M_WAITOK);
132 
133 	mtx_lock(&sc->ic_lock);
134 	while (sc->ic_flags & IC_BUFFERS_BUSY) {
135 		sc->ic_flags |= IC_BUFFER_WAITER;
136 		mtx_sleep(sc, &sc->ic_lock, 0, "icalloc", 0);
137 		sc->ic_flags &= ~IC_BUFFER_WAITER;
138 	}
139 
140 	free(sc->ic_obuf, M_DEVBUF);
141 	free(sc->ic_ifbuf, M_DEVBUF);
142 	sc->ic_obuf = obuf;
143 	sc->ic_ifbuf = ifbuf;
144 	sc->ic_ifp->if_mtu = mtu;
145 	mtx_unlock(&sc->ic_lock);
146 }
147 
148 /*
149  * icprobe()
150  */
151 static int
152 icprobe(device_t dev)
153 {
154 	return (BUS_PROBE_NOWILDCARD);
155 }
156 
157 /*
158  * icattach()
159  */
160 static int
161 icattach(device_t dev)
162 {
163 	struct ic_softc *sc = (struct ic_softc *)device_get_softc(dev);
164 	struct ifnet *ifp;
165 
166 	ifp = sc->ic_ifp = if_alloc(IFT_PARA);
167 	if (ifp == NULL)
168 		return (ENOSPC);
169 
170 	mtx_init(&sc->ic_lock, device_get_nameunit(dev), MTX_NETWORK_LOCK,
171 	    MTX_DEF);
172 	sc->ic_addr = PCF_MASTER_ADDRESS;	/* XXX only PCF masters */
173 	sc->ic_dev = dev;
174 
175 	ifp->if_softc = sc;
176 	if_initname(ifp, device_get_name(dev), device_get_unit(dev));
177 	ifp->if_flags = IFF_SIMPLEX | IFF_POINTOPOINT | IFF_MULTICAST;
178 	ifp->if_ioctl = icioctl;
179 	ifp->if_output = icoutput;
180 	ifp->if_hdrlen = 0;
181 	ifp->if_addrlen = 0;
182 	ifp->if_snd.ifq_maxlen = ifqmaxlen;
183 
184 	ic_alloc_buffers(sc, ICMTU);
185 
186 	if_attach(ifp);
187 
188 	bpfattach(ifp, DLT_NULL, ICHDRLEN);
189 
190 	return (0);
191 }
192 
193 /*
194  * iciotcl()
195  */
196 static int
197 icioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
198 {
199 	struct ic_softc *sc = ifp->if_softc;
200 	device_t icdev = sc->ic_dev;
201 	device_t parent = device_get_parent(icdev);
202 	struct ifaddr *ifa = (struct ifaddr *)data;
203 	struct ifreq *ifr = (struct ifreq *)data;
204 	int error;
205 
206 	switch (cmd) {
207 
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 == NULL)
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 occurred 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 		if_inc_counter(sc->ic_ifp, IFCOUNTER_IPACKETS, 1);
306 		if_inc_counter(sc->ic_ifp, IFCOUNTER_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 			struct epoch_tracker et;
311 
312 			mtx_unlock(&sc->ic_lock);
313 			M_SETFIB(top, sc->ic_ifp->if_fib);
314 			NET_EPOCH_ENTER(et);
315 			netisr_dispatch(NETISR_IP, top);
316 			NET_EPOCH_EXIT(et);
317 			mtx_lock(&sc->ic_lock);
318 		}
319 		break;
320 	err:
321 		if_printf(sc->ic_ifp, "errors (%d)!\n", sc->ic_iferrs);
322 		sc->ic_iferrs = 0;			/* reset error count */
323 		if_inc_counter(sc->ic_ifp, IFCOUNTER_IERRORS, 1);
324 		break;
325 
326 	case INTR_RECEIVE:
327 		if (sc->ic_xfercnt >= sc->ic_ifp->if_mtu + ICHDRLEN) {
328 			sc->ic_iferrs++;
329 		} else {
330 			*sc->ic_cp++ = *ptr;
331 			sc->ic_xfercnt++;
332 		}
333 		break;
334 
335 	case INTR_NOACK:			/* xfer terminated by master */
336 		break;
337 
338 	case INTR_TRANSMIT:
339 		*ptr = 0xff;					/* XXX */
340 	  	break;
341 
342 	case INTR_ERROR:
343 		sc->ic_iferrs++;
344 		break;
345 
346 	default:
347 		panic("%s: unknown event (%d)!", __func__, event);
348 	}
349 
350 	mtx_unlock(&sc->ic_lock);
351 	return (0);
352 }
353 
354 /*
355  * icoutput()
356  */
357 static int
358 icoutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
359     struct route *ro)
360 {
361 	struct ic_softc *sc = ifp->if_softc;
362 	device_t icdev = sc->ic_dev;
363 	device_t parent = device_get_parent(icdev);
364 	int len, sent;
365 	struct mbuf *mm;
366 	u_char *cp;
367 	u_int32_t hdr;
368 
369 	/* BPF writes need to be handled specially. */
370 	if (dst->sa_family == AF_UNSPEC)
371 		bcopy(dst->sa_data, &hdr, sizeof(hdr));
372 	else
373 		hdr = RO_GET_FAMILY(ro, dst);
374 
375 	mtx_lock(&sc->ic_lock);
376 	ifp->if_drv_flags |= IFF_DRV_RUNNING;
377 
378 	/* already sending? */
379 	if (sc->ic_flags & IC_SENDING) {
380 		if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
381 		goto error;
382 	}
383 
384 	/* insert header */
385 	bcopy ((char *)&hdr, sc->ic_obuf, ICHDRLEN);
386 
387 	cp = sc->ic_obuf + ICHDRLEN;
388 	len = 0;
389 	mm = m;
390 	do {
391 		if (len + mm->m_len > sc->ic_ifp->if_mtu) {
392 			/* packet too large */
393 			if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
394 			goto error;
395 		}
396 
397 		bcopy(mtod(mm,char *), cp, mm->m_len);
398 		cp += mm->m_len;
399 		len += mm->m_len;
400 
401 	} while ((mm = mm->m_next));
402 
403 	BPF_MTAP2(ifp, &hdr, sizeof(hdr), m);
404 
405 	sc->ic_flags |= (IC_SENDING | IC_OBUF_BUSY);
406 
407 	m_freem(m);
408 	mtx_unlock(&sc->ic_lock);
409 
410 	/* send the packet */
411 	if (iicbus_block_write(parent, sc->ic_addr, sc->ic_obuf,
412 				len + ICHDRLEN, &sent))
413 
414 		if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
415 	else {
416 		if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
417 		if_inc_counter(ifp, IFCOUNTER_OBYTES, len);
418 	}
419 
420 	mtx_lock(&sc->ic_lock);
421 	sc->ic_flags &= ~(IC_SENDING | IC_OBUF_BUSY);
422 	if ((sc->ic_flags & (IC_BUFFERS_BUSY | IC_BUFFER_WAITER)) ==
423 	    IC_BUFFER_WAITER)
424 		wakeup(&sc);
425 	mtx_unlock(&sc->ic_lock);
426 
427 	return (0);
428 
429 error:
430 	m_freem(m);
431 	mtx_unlock(&sc->ic_lock);
432 
433 	return(0);
434 }
435 
436 DRIVER_MODULE(ic, iicbus, ic_driver, 0, 0);
437 MODULE_DEPEND(ic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
438 MODULE_VERSION(ic, 1);
439