xref: /freebsd/sys/dev/iicbus/if_ic.c (revision ce3adf4362fcca6a43e500b2531f0038adbfbd21)
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 *, const 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 SIOCAIFADDR:
208 	case SIOCSIFADDR:
209 		if (ifa->ifa_addr->sa_family != AF_INET)
210 			return (EAFNOSUPPORT);
211 		mtx_lock(&sc->ic_lock);
212 		ifp->if_flags |= IFF_UP;
213 		goto locked;
214 	case SIOCSIFFLAGS:
215 		mtx_lock(&sc->ic_lock);
216 	locked:
217 		if ((!(ifp->if_flags & IFF_UP)) &&
218 		    (ifp->if_drv_flags & IFF_DRV_RUNNING)) {
219 
220 			/* XXX disable PCF */
221 			ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
222 			mtx_unlock(&sc->ic_lock);
223 
224 			/* IFF_UP is not set, try to release the bus anyway */
225 			iicbus_release_bus(parent, icdev);
226 			break;
227 		}
228 		if (((ifp->if_flags & IFF_UP)) &&
229 		    (!(ifp->if_drv_flags & IFF_DRV_RUNNING))) {
230 			mtx_unlock(&sc->ic_lock);
231 			if ((error = iicbus_request_bus(parent, icdev,
232 			    IIC_WAIT | IIC_INTR)))
233 				return (error);
234 			mtx_lock(&sc->ic_lock);
235 			iicbus_reset(parent, IIC_FASTEST, 0, NULL);
236 			ifp->if_drv_flags |= IFF_DRV_RUNNING;
237 		}
238 		mtx_unlock(&sc->ic_lock);
239 		break;
240 
241 	case SIOCSIFMTU:
242 		ic_alloc_buffers(sc, ifr->ifr_mtu);
243 		break;
244 
245 	case SIOCGIFMTU:
246 		mtx_lock(&sc->ic_lock);
247 		ifr->ifr_mtu = sc->ic_ifp->if_mtu;
248 		mtx_unlock(&sc->ic_lock);
249 		break;
250 
251 	case SIOCADDMULTI:
252 	case SIOCDELMULTI:
253 		if (ifr == 0)
254 			return (EAFNOSUPPORT);		/* XXX */
255 		switch (ifr->ifr_addr.sa_family) {
256 		case AF_INET:
257 			break;
258 		default:
259 			return (EAFNOSUPPORT);
260 		}
261 		break;
262 	default:
263 		return (EINVAL);
264 	}
265 	return (0);
266 }
267 
268 /*
269  * icintr()
270  */
271 static int
272 icintr(device_t dev, int event, char *ptr)
273 {
274 	struct ic_softc *sc = (struct ic_softc *)device_get_softc(dev);
275 	struct mbuf *top;
276 	int len;
277 
278 	mtx_lock(&sc->ic_lock);
279 
280 	switch (event) {
281 
282 	case INTR_GENERAL:
283 	case INTR_START:
284 		sc->ic_cp = sc->ic_ifbuf;
285 		sc->ic_xfercnt = 0;
286 		sc->ic_flags |= IC_IFBUF_BUSY;
287 		break;
288 
289 	case INTR_STOP:
290 
291 		/* if any error occured during transfert,
292 		 * drop the packet */
293 		sc->ic_flags &= ~IC_IFBUF_BUSY;
294 		if ((sc->ic_flags & (IC_BUFFERS_BUSY | IC_BUFFER_WAITER)) ==
295 		    IC_BUFFER_WAITER)
296 			wakeup(&sc);
297 		if (sc->ic_iferrs)
298 			goto err;
299 		if ((len = sc->ic_xfercnt) == 0)
300 			break;					/* ignore */
301 		if (len <= ICHDRLEN)
302 			goto err;
303 		len -= ICHDRLEN;
304 		sc->ic_ifp->if_ipackets++;
305 		sc->ic_ifp->if_ibytes += len;
306 		BPF_TAP(sc->ic_ifp, sc->ic_ifbuf, len + ICHDRLEN);
307 		top = m_devget(sc->ic_ifbuf + ICHDRLEN, len, 0, sc->ic_ifp, 0);
308 		if (top) {
309 			mtx_unlock(&sc->ic_lock);
310 			M_SETFIB(top, sc->ic_ifp->if_fib);
311 			netisr_dispatch(NETISR_IP, top);
312 			mtx_lock(&sc->ic_lock);
313 		}
314 		break;
315 	err:
316 		if_printf(sc->ic_ifp, "errors (%d)!\n", sc->ic_iferrs);
317 		sc->ic_iferrs = 0;			/* reset error count */
318 		sc->ic_ifp->if_ierrors++;
319 		break;
320 
321 	case INTR_RECEIVE:
322 		if (sc->ic_xfercnt >= sc->ic_ifp->if_mtu + ICHDRLEN) {
323 			sc->ic_iferrs++;
324 		} else {
325 			*sc->ic_cp++ = *ptr;
326 			sc->ic_xfercnt++;
327 		}
328 		break;
329 
330 	case INTR_NOACK:			/* xfer terminated by master */
331 		break;
332 
333 	case INTR_TRANSMIT:
334 		*ptr = 0xff;					/* XXX */
335 	  	break;
336 
337 	case INTR_ERROR:
338 		sc->ic_iferrs++;
339 		break;
340 
341 	default:
342 		panic("%s: unknown event (%d)!", __func__, event);
343 	}
344 
345 	mtx_unlock(&sc->ic_lock);
346 	return (0);
347 }
348 
349 /*
350  * icoutput()
351  */
352 static int
353 icoutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
354     struct route *ro)
355 {
356 	struct ic_softc *sc = ifp->if_softc;
357 	device_t icdev = sc->ic_dev;
358 	device_t parent = device_get_parent(icdev);
359 	int len, sent;
360 	struct mbuf *mm;
361 	u_char *cp;
362 	u_int32_t hdr;
363 
364 	/* BPF writes need to be handled specially. */
365 	if (dst->sa_family == AF_UNSPEC)
366 		bcopy(dst->sa_data, &hdr, sizeof(hdr));
367 	else
368 		hdr = dst->sa_family;
369 
370 	mtx_lock(&sc->ic_lock);
371 	ifp->if_drv_flags |= IFF_DRV_RUNNING;
372 
373 	/* already sending? */
374 	if (sc->ic_flags & IC_SENDING) {
375 		ifp->if_oerrors++;
376 		goto error;
377 	}
378 
379 	/* insert header */
380 	bcopy ((char *)&hdr, sc->ic_obuf, ICHDRLEN);
381 
382 	cp = sc->ic_obuf + ICHDRLEN;
383 	len = 0;
384 	mm = m;
385 	do {
386 		if (len + mm->m_len > sc->ic_ifp->if_mtu) {
387 			/* packet too large */
388 			ifp->if_oerrors++;
389 			goto error;
390 		}
391 
392 		bcopy(mtod(mm,char *), cp, mm->m_len);
393 		cp += mm->m_len;
394 		len += mm->m_len;
395 
396 	} while ((mm = mm->m_next));
397 
398 	BPF_MTAP2(ifp, &hdr, sizeof(hdr), m);
399 
400 	sc->ic_flags |= (IC_SENDING | IC_OBUF_BUSY);
401 
402 	m_freem(m);
403 	mtx_unlock(&sc->ic_lock);
404 
405 	/* send the packet */
406 	if (iicbus_block_write(parent, sc->ic_addr, sc->ic_obuf,
407 				len + ICHDRLEN, &sent))
408 
409 		ifp->if_oerrors++;
410 	else {
411 		ifp->if_opackets++;
412 		ifp->if_obytes += len;
413 	}
414 
415 	mtx_lock(&sc->ic_lock);
416 	sc->ic_flags &= ~(IC_SENDING | IC_OBUF_BUSY);
417 	if ((sc->ic_flags & (IC_BUFFERS_BUSY | IC_BUFFER_WAITER)) ==
418 	    IC_BUFFER_WAITER)
419 		wakeup(&sc);
420 	mtx_unlock(&sc->ic_lock);
421 
422 	return (0);
423 
424 error:
425 	m_freem(m);
426 	mtx_unlock(&sc->ic_lock);
427 
428 	return(0);
429 }
430 
431 DRIVER_MODULE(ic, iicbus, ic_driver, ic_devclass, 0, 0);
432 MODULE_DEPEND(ic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
433 MODULE_VERSION(ic, 1);
434