xref: /netbsd-src/sys/arch/arm/sunxi/sunxi_can.c (revision 82d56013d7b633d116a93943de88e08335357a7c)
1 /*	$NetBSD: sunxi_can.c,v 1.8 2021/01/27 03:10:20 thorpej Exp $	*/
2 
3 /*-
4  * Copyright (c) 2017,2018 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Manuel Bouyer.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 
33 #include "locators.h"
34 #include "opt_can.h"
35 
36 
37 #include <sys/cdefs.h>
38 
39 __KERNEL_RCSID(1, "$NetBSD: sunxi_can.c,v 1.8 2021/01/27 03:10:20 thorpej Exp $");
40 
41 #include <sys/param.h>
42 #include <sys/bus.h>
43 #include <sys/device.h>
44 #include <sys/intr.h>
45 #include <sys/ioctl.h>
46 #include <sys/mutex.h>
47 #include <sys/rndsource.h>
48 #include <sys/mbuf.h>
49 #include <sys/systm.h>
50 
51 #include <net/if.h>
52 #include <net/if_types.h>
53 #include <net/bpf.h>
54 
55 #ifdef CAN
56 #include <netcan/can.h>
57 #include <netcan/can_var.h>
58 #endif
59 
60 #include <dev/fdt/fdtvar.h>
61 
62 #include <arm/sunxi/sunxi_can.h>
63 
64 /* shortcut for all error interrupts */
65 #define SUNXI_CAN_INT_ALLERRS (\
66 	SUNXI_CAN_INT_BERR | \
67 	SUNXI_CAN_INT_ARB_LOST | \
68 	SUNXI_CAN_INT_ERR_PASSIVE | \
69 	SUNXI_CAN_INT_DATA_OR | \
70 	SUNXI_CAN_INT_ERR \
71     )
72 
73 struct sunxi_can_softc {
74 	struct canif_softc sc_cansc;
75 	bus_space_tag_t sc_bst;
76 	bus_space_handle_t sc_bsh;
77 	kmutex_t sc_intr_lock;
78 	void *sc_ih;
79 	struct ifnet *sc_ifp;
80 	krndsource_t sc_rnd_source;	/* random source */
81 	struct mbuf *sc_m_transmit; /* mbuf being transmitted */
82 };
83 #define sc_dev		sc_cansc.csc_dev
84 #define sc_timecaps	sc_cansc.csc_timecaps
85 #define sc_timings	sc_cansc.csc_timings
86 #define sc_linkmodes	sc_cansc.csc_linkmodes
87 
88 static const struct device_compatible_entry compat_data[] = {
89 	{ .compat = "allwinner,sun4i-a10-can" },
90 	DEVICE_COMPAT_EOL
91 };
92 
93 static int sunxi_can_match(device_t, cfdata_t, void *);
94 static void sunxi_can_attach(device_t, device_t, void *);
95 
96 static int sunxi_can_intr(void *);
97 
98 static void sunxi_can_ifstart(struct ifnet *);
99 static int sunxi_can_ifioctl(struct ifnet *, u_long, void *);
100 static void sunxi_can_ifwatchdog(struct ifnet *);
101 
102 static void sunxi_can_enter_reset(struct sunxi_can_softc *);
103 static void sunxi_can_exit_reset(struct sunxi_can_softc *);
104 
105 CFATTACH_DECL_NEW(sunxi_can, sizeof(struct sunxi_can_softc),
106 	sunxi_can_match, sunxi_can_attach, NULL, NULL);
107 
108 static inline uint32_t
109 sunxi_can_read(struct sunxi_can_softc *sc, bus_size_t o)
110 {
111 	return bus_space_read_4(sc->sc_bst, sc->sc_bsh, o);
112 }
113 
114 static inline void
115 sunxi_can_write(struct sunxi_can_softc *sc, bus_size_t o, uint32_t v)
116 {
117 	return bus_space_write_4(sc->sc_bst, sc->sc_bsh, o, v);
118 }
119 
120 static int
121 sunxi_can_match(device_t parent, cfdata_t cf, void *aux)
122 {
123 	struct fdt_attach_args * const faa = aux;
124 
125 	return of_compatible_match(faa->faa_phandle, compat_data);
126 }
127 
128 static void
129 sunxi_can_attach(device_t parent, device_t self, void *aux)
130 {
131 	struct sunxi_can_softc * const sc = device_private(self);
132 	struct fdt_attach_args * const faa = aux;
133 	struct ifnet *ifp;
134 	const int phandle = faa->faa_phandle;
135 	bus_addr_t addr;
136 	bus_size_t size;
137 	char intrstr[128];
138 	struct clk *clk;
139 	struct fdtbus_reset *rst;
140 
141 	sc->sc_dev = self;
142 	mutex_init(&sc->sc_intr_lock, MUTEX_DEFAULT, IPL_NET);
143 
144 	sc->sc_bst = faa->faa_bst;
145 	if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
146 		aprint_error(": couldn't get registers\n");
147 		return;
148 	}
149 
150 	if (bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh) != 0) {
151 		aprint_error(": couldn't map registers\n");
152 		return;
153 	}
154 
155 	if (!fdtbus_intr_str(phandle, 0, intrstr, sizeof(intrstr))) {
156 		aprint_error(": failed to decode interrupt\n");
157 		return;
158 	}
159 
160 	if ((clk = fdtbus_clock_get_index(phandle, 0)) != NULL) {
161 		if (clk_enable(clk) != 0) {
162 			aprint_error(": couldn't enable clock\n");
163 			return;
164 		}
165 	}
166 
167 	if ((rst = fdtbus_reset_get_index(phandle, 0)) != NULL) {
168 		if (fdtbus_reset_deassert(rst) != 0) {
169 			aprint_error(": couldn't de-assert reset\n");
170 			return;
171 		}
172 	}
173 
174 	sc->sc_timecaps.cltc_prop_min = 0;
175 	sc->sc_timecaps.cltc_prop_max = 0;
176 	sc->sc_timecaps.cltc_ps1_min = 1;
177 	sc->sc_timecaps.cltc_ps1_max = 16;
178 	sc->sc_timecaps.cltc_ps2_min = 1;
179 	sc->sc_timecaps.cltc_ps2_max = 8;
180 	sc->sc_timecaps.cltc_sjw_max = 4;
181 	sc->sc_timecaps.cltc_brp_min = 1;
182 	sc->sc_timecaps.cltc_brp_max = 64;
183 	sc->sc_timecaps.cltc_brp_inc = 1;
184 	sc->sc_timecaps.cltc_clock_freq = clk_get_rate(clk);
185 	sc->sc_timecaps.cltc_linkmode_caps =
186 	    CAN_LINKMODE_3SAMPLES | CAN_LINKMODE_LISTENONLY |
187 	    CAN_LINKMODE_LOOPBACK;
188 	can_ifinit_timings(&sc->sc_cansc);
189 	sc->sc_timings.clt_prop = 0;
190 	sc->sc_timings.clt_sjw = 1;
191 
192 	aprint_naive("\n");
193 	aprint_normal(": CAN bus controller\n");
194 	aprint_debug_dev(self, ": clock freq %d\n",
195 	    sc->sc_timecaps.cltc_clock_freq);
196 
197 	sunxi_can_enter_reset(sc);
198 	/*
199 	 * Disable and then clear all interrupts
200 	 */
201 	sunxi_can_write(sc, SUNXI_CAN_INTE_REG, 0);
202 	sunxi_can_write(sc, SUNXI_CAN_INT_REG,
203 	    sunxi_can_read(sc, SUNXI_CAN_INT_REG));
204 
205 	sc->sc_ih = fdtbus_intr_establish_xname(phandle, 0, IPL_NET, 0,
206 	    sunxi_can_intr, sc, device_xname(self));
207 	if (sc->sc_ih == NULL) {
208 		aprint_error_dev(self, "failed to establish interrupt on %s\n",
209 		    intrstr);
210 		return;
211 	}
212 	aprint_normal_dev(self, "interrupting on %s\n", intrstr);
213 
214 	ifp = if_alloc(IFT_OTHER);
215 	sc->sc_ifp = ifp;
216 	strlcpy(ifp->if_xname, device_xname(self), IFNAMSIZ);
217 	ifp->if_softc = sc;
218 	ifp->if_capabilities = 0;
219 	ifp->if_flags = 0;
220 	ifp->if_start = sunxi_can_ifstart;
221 	ifp->if_ioctl = sunxi_can_ifioctl;
222 	ifp->if_watchdog = sunxi_can_ifwatchdog;
223 
224 	/*
225 	 * Attach the interface.
226 	 */
227 	can_ifattach(ifp);
228 	if_deferred_start_init(ifp, NULL);
229 	bpf_mtap_softint_init(ifp);
230 	rnd_attach_source(&sc->sc_rnd_source, device_xname(self),
231 	    RND_TYPE_NET, RND_FLAG_DEFAULT);
232 #ifdef MBUFTRACE
233 	ifp->if_mowner = malloc(sizeof(struct mowner), M_DEVBUF,
234 	    M_WAITOK | M_ZERO);
235 	strlcpy(ifp->if_mowner->mo_name, ifp->if_xname,
236 		sizeof(ifp->if_mowner->mo_name));
237 	MOWNER_ATTACH(ifp->if_mowner);
238 #endif
239 }
240 
241 static void
242 sunxi_can_rx_intr(struct sunxi_can_softc *sc)
243 {
244 	uint32_t reg0v;
245 	struct mbuf *m;
246 	struct ifnet  *ifp = sc->sc_ifp;
247 	struct can_frame *cf;
248 	int dlc;
249 	int regd, i;
250 
251 	KASSERT(mutex_owned(&sc->sc_intr_lock));
252 	reg0v = sunxi_can_read(sc, SUNXI_CAN_TXBUF0_REG);
253 	dlc = reg0v & SUNXI_CAN_TXBUF0_DL;
254 
255 	if (dlc > CAN_MAX_DLC) {
256 		if_statinc(ifp, if_ierrors);
257 		sunxi_can_write(sc, SUNXI_CAN_CMD_REG, SUNXI_CAN_CMD_REL_RX_BUF);
258 		return;
259 	}
260 
261 	m = m_gethdr(M_NOWAIT, MT_HEADER);
262 	if (m == NULL) {
263 		if_statinc(ifp, if_ierrors);
264 		sunxi_can_write(sc, SUNXI_CAN_CMD_REG, SUNXI_CAN_CMD_REL_RX_BUF);
265 		return;
266 	}
267 	cf = mtod(m, struct can_frame *);
268 	memset(cf, 0, sizeof(struct can_frame));
269 
270 	cf->can_dlc = dlc;
271 
272 	if (reg0v & SUNXI_CAN_TXBUF0_EFF) {
273 		cf->can_id =
274 		    (sunxi_can_read(sc, SUNXI_CAN_TXBUF1_REG) << 21) |
275 		    (sunxi_can_read(sc, SUNXI_CAN_TXBUF2_REG) << 13) |
276 		    (sunxi_can_read(sc, SUNXI_CAN_TXBUF3_REG) << 5) |
277 		    ((sunxi_can_read(sc, SUNXI_CAN_TXBUF4_REG) >> 3) & 0x1f);
278 		cf->can_id |= CAN_EFF_FLAG;
279 		regd = SUNXI_CAN_TXBUF5_REG;
280 	} else {
281 		cf->can_id =
282 		    (sunxi_can_read(sc, SUNXI_CAN_TXBUF1_REG) << 3) |
283 		    ((sunxi_can_read(sc, SUNXI_CAN_TXBUF2_REG) << 5) & 0x7);
284 		regd = SUNXI_CAN_TXBUF3_REG;
285 	}
286 	if (reg0v & SUNXI_CAN_TXBUF0_RTR) {
287 		cf->can_id |= CAN_RTR_FLAG;
288 	} else {
289 		for (i = 0; i < cf->can_dlc; i++) {
290 			cf->data[i] = sunxi_can_read(sc, regd + i * 4);
291 		}
292 	}
293 	sunxi_can_write(sc, SUNXI_CAN_CMD_REG, SUNXI_CAN_CMD_REL_RX_BUF);
294 	m->m_len = m->m_pkthdr.len = CAN_MTU;
295 	if_statadd(ifp, if_ibytes, m->m_len);
296 	m_set_rcvif(m, ifp);
297 	can_bpf_mtap(ifp, m, 1);
298 	can_input(ifp, m);
299 }
300 
301 static void
302 sunxi_can_tx_intr(struct sunxi_can_softc *sc)
303 {
304 	struct ifnet * const ifp = sc->sc_ifp;
305 	struct mbuf *m;
306 
307 	KASSERT(mutex_owned(&sc->sc_intr_lock));
308 	if ((m = sc->sc_m_transmit) != NULL) {
309 		if_statadd2(ifp, if_obytes, m->m_len, if_opackets, 1);
310 		can_mbuf_tag_clean(m);
311 		m_set_rcvif(m, ifp);
312 		can_input(ifp, m); /* loopback */
313 		sc->sc_m_transmit = NULL;
314 		ifp->if_timer = 0;
315 	}
316 	ifp->if_flags &= ~IFF_OACTIVE;
317 	if_schedule_deferred_start(ifp);
318 }
319 
320 static int
321 sunxi_can_tx_abort(struct sunxi_can_softc *sc)
322 {
323 	KASSERT(mutex_owned(&sc->sc_intr_lock));
324 	if (sc->sc_m_transmit) {
325 		m_freem(sc->sc_m_transmit);
326 		sc->sc_m_transmit = NULL;
327 		sc->sc_ifp->if_timer = 0;
328 		/*
329 		 * the transmit abort will trigger a TX interrupt
330 		 * which will restart the queue or cleae OACTIVE,
331 		 * as appropriate
332 		 */
333 		sunxi_can_write(sc, SUNXI_CAN_CMD_REG, SUNXI_CAN_CMD_ABT_REQ);
334 		return 1;
335 	}
336 	return 0;
337 }
338 
339 static void
340 sunxi_can_err_intr(struct sunxi_can_softc *sc, uint32_t irq, uint32_t sts)
341 {
342 	struct ifnet * const ifp = sc->sc_ifp;
343 	KASSERT(mutex_owned(&sc->sc_intr_lock));
344 	int txerr = 0;
345 	uint32_t reg;
346 
347 	if (irq & SUNXI_CAN_INT_DATA_OR) {
348 		if_statinc(ifp, if_ierrors);
349 		sunxi_can_write(sc, SUNXI_CAN_CMD_REG, SUNXI_CAN_CMD_CLR_OR);
350 	}
351 	if (irq & SUNXI_CAN_INT_ERR) {
352 		reg = sunxi_can_read(sc, SUNXI_CAN_REC_REG);
353 		printf("%s: ERR interrupt status 0x%x counters 0x%x\n",
354 		    device_xname(sc->sc_dev), sts, reg);
355 
356 	}
357 	if (irq & SUNXI_CAN_INT_BERR) {
358 		if (sts & SUNXI_CAN_STA_TX)
359 			txerr++;
360 		if (sts & SUNXI_CAN_STA_RX)
361 			if_statinc(ifp, if_ierrors);
362 	}
363 	if (irq & SUNXI_CAN_INT_ERR_PASSIVE) {
364 		printf("%s: PASSV interrupt status 0x%x\n",
365 		    device_xname(sc->sc_dev), sts);
366 	}
367 	if (irq & SUNXI_CAN_INT_ARB_LOST) {
368 		txerr++;
369 	}
370 	if (txerr) {
371 		if_statadd(ifp, if_oerrors, txerr);
372 		(void) sunxi_can_tx_abort(sc);
373 	}
374 }
375 
376 int
377 sunxi_can_intr(void *arg)
378 {
379 	struct sunxi_can_softc * const sc = arg;
380 	int rv = 0;
381 	int irq;
382 
383 	mutex_enter(&sc->sc_intr_lock);
384 
385 	while ((irq = sunxi_can_read(sc, SUNXI_CAN_INT_REG)) != 0) {
386 		uint32_t sts = sunxi_can_read(sc, SUNXI_CAN_STA_REG);
387 		rv = 1;
388 
389 		if (irq & SUNXI_CAN_INT_TX_FLAG) {
390 			sunxi_can_tx_intr(sc);
391 		}
392 		if (irq & SUNXI_CAN_INT_RX_FLAG) {
393 			while (sts & SUNXI_CAN_STA_RX_RDY) {
394 				sunxi_can_rx_intr(sc);
395 				sts = sunxi_can_read(sc, SUNXI_CAN_STA_REG);
396 			}
397 		}
398 		if (irq & SUNXI_CAN_INT_ALLERRS) {
399 			sunxi_can_err_intr(sc, irq, sts);
400 		}
401 		sunxi_can_write(sc, SUNXI_CAN_INT_REG, irq);
402                 rnd_add_uint32(&sc->sc_rnd_source, irq);
403 
404 	}
405 	mutex_exit(&sc->sc_intr_lock);
406 
407 	return rv;
408 }
409 
410 void
411 sunxi_can_ifstart(struct ifnet *ifp)
412 {
413 	struct sunxi_can_softc * const sc = ifp->if_softc;
414 	struct mbuf *m;
415 	struct can_frame *cf;
416 	int regd;
417 	uint32_t reg0val;
418 	int i;
419 
420 	mutex_enter(&sc->sc_intr_lock);
421 	if (ifp->if_flags & IFF_OACTIVE)
422 		goto out;
423 
424 	IF_DEQUEUE(&ifp->if_snd, m);
425 
426 	if (m == NULL)
427 		goto out;
428 
429 	MCLAIM(m, ifp->if_mowner);
430 	sc->sc_m_transmit = m;
431 
432 	KASSERT((m->m_flags & M_PKTHDR) != 0);
433 	KASSERT(m->m_len == m->m_pkthdr.len);
434 
435 	cf = mtod(m, struct can_frame *);
436 	reg0val = cf->can_dlc & SUNXI_CAN_TXBUF0_DL;
437 	if (cf->can_id & CAN_RTR_FLAG)
438 		reg0val |= SUNXI_CAN_TXBUF0_RTR;
439 
440 	if (cf->can_id & CAN_EFF_FLAG) {
441 		reg0val |= SUNXI_CAN_TXBUF0_EFF;
442 		sunxi_can_write(sc, SUNXI_CAN_TXBUF1_REG,
443 		    (cf->can_id >> 21) & 0xff);
444 		sunxi_can_write(sc, SUNXI_CAN_TXBUF2_REG,
445 		    (cf->can_id >> 13) & 0xff);
446 		sunxi_can_write(sc, SUNXI_CAN_TXBUF3_REG,
447 		    (cf->can_id >> 5) & 0xff);
448 		sunxi_can_write(sc, SUNXI_CAN_TXBUF4_REG,
449 		    (cf->can_id << 3) & 0xf8);
450 		regd = SUNXI_CAN_TXBUF5_REG;
451 	} else {
452 		sunxi_can_write(sc, SUNXI_CAN_TXBUF1_REG,
453 		    (cf->can_id >> 3) & 0xff);
454 		sunxi_can_write(sc, SUNXI_CAN_TXBUF2_REG,
455 		    (cf->can_id << 5) & 0xe0);
456 		regd = SUNXI_CAN_TXBUF3_REG;
457 	}
458 
459 	for (i = 0; i < cf->can_dlc; i++) {
460 		sunxi_can_write(sc, regd + i * 4, cf->data[i]);
461 	}
462 	sunxi_can_write(sc, SUNXI_CAN_TXBUF0_REG, reg0val);
463 
464 	if (sc->sc_linkmodes & CAN_LINKMODE_LOOPBACK) {
465 		sunxi_can_write(sc, SUNXI_CAN_CMD_REG,
466 			SUNXI_CAN_CMD_TANS_REQ | SUNXI_CAN_CMD_SELF_REQ);
467 	} else {
468 		sunxi_can_write(sc, SUNXI_CAN_CMD_REG, SUNXI_CAN_CMD_TANS_REQ);
469 	}
470 	ifp->if_flags |= IFF_OACTIVE;
471 	ifp->if_timer = 5;
472 	can_bpf_mtap(ifp, m, 0);
473 out:
474 	mutex_exit(&sc->sc_intr_lock);
475 }
476 
477 static int
478 sunxi_can_ifup(struct sunxi_can_softc * const sc)
479 {
480 	uint32_t reg;
481 
482 	/* setup timings and mode - has to be done in reset */
483 	reg = SUNXI_CAN_MODSEL_RST;
484 	if (sc->sc_linkmodes & CAN_LINKMODE_LISTENONLY)
485 		reg |= SUNXI_CAN_MODSEL_LST_ONLY;
486 
487 	if (sc->sc_linkmodes & CAN_LINKMODE_LOOPBACK)
488 		reg |= SUNXI_CAN_MODSEL_LB_MOD;
489 
490 	sunxi_can_write(sc, SUNXI_CAN_MODSEL_REG, reg);
491 
492 	reg = 0;
493 	if (sc->sc_timings.clt_prop != 0)
494 		return EINVAL;
495 
496 	if (sc->sc_timings.clt_brp > sc->sc_timecaps.cltc_brp_max ||
497 	   sc->sc_timings.clt_brp < sc->sc_timecaps.cltc_brp_min)
498 		return EINVAL;
499 	reg |= (sc->sc_timings.clt_brp - 1) << 0;
500 
501 	if (sc->sc_timings.clt_ps1 > sc->sc_timecaps.cltc_ps1_max ||
502 	   sc->sc_timings.clt_ps1 < sc->sc_timecaps.cltc_ps1_min)
503 		return EINVAL;
504 	reg |= (sc->sc_timings.clt_ps1 - 1) << 16;
505 
506 	if (sc->sc_timings.clt_ps2 > sc->sc_timecaps.cltc_ps2_max ||
507 	   sc->sc_timings.clt_ps2 < sc->sc_timecaps.cltc_ps2_min)
508 		return EINVAL;
509 	reg |= (sc->sc_timings.clt_ps2 - 1) << 20;
510 
511 	if (sc->sc_timings.clt_sjw > sc->sc_timecaps.cltc_sjw_max ||
512 	   sc->sc_timings.clt_sjw < 1)
513 		return EINVAL;
514 	reg |= (sc->sc_timings.clt_sjw - 1) << 14;
515 
516 	if (sc->sc_linkmodes & CAN_LINKMODE_3SAMPLES)
517 		reg |= SUNXI_CAN_BUS_TIME_SAM;
518 
519 	sunxi_can_write(sc, SUNXI_CAN_BUS_TIME_REG, reg);
520 
521 	/* set filters to accept all frames */
522 	sunxi_can_write(sc, SUNXI_CAN_ACPC, 0x00000000);
523 	sunxi_can_write(sc, SUNXI_CAN_ACPM, 0xffffffff);
524 
525 	/* clear errors counter */
526 	sunxi_can_write(sc, SUNXI_CAN_REC_REG, 0);
527 
528 	/* leave reset mode and enable interrupts */
529 	sunxi_can_exit_reset(sc);
530 	sunxi_can_write(sc, SUNXI_CAN_INTE_REG,
531 	    SUNXI_CAN_INT_TX_FLAG | SUNXI_CAN_INT_RX_FLAG | SUNXI_CAN_INT_ALLERRS);
532 	sc->sc_ifp->if_flags |= IFF_RUNNING;
533 	return 0;
534 }
535 
536 static void
537 sunxi_can_ifdown(struct sunxi_can_softc * const sc)
538 {
539 	sc->sc_ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
540 	sc->sc_ifp->if_timer = 0;
541 	sunxi_can_enter_reset(sc);
542 	sunxi_can_write(sc, SUNXI_CAN_INTE_REG, 0);
543 	sunxi_can_write(sc, SUNXI_CAN_INT_REG,
544 	    sunxi_can_read(sc, SUNXI_CAN_INT_REG));
545 }
546 
547 static int
548 sunxi_can_ifioctl(struct ifnet *ifp, u_long cmd, void *data)
549 {
550 	struct sunxi_can_softc * const sc = ifp->if_softc;
551 	struct ifreq *ifr = (struct ifreq *)data;
552 	int error = 0;
553 
554 	mutex_enter(&sc->sc_intr_lock);
555 
556 	switch (cmd) {
557 	case SIOCINITIFADDR:
558 		error = EAFNOSUPPORT;
559 		break;
560 	case SIOCSIFMTU:
561 		if ((unsigned)ifr->ifr_mtu != sizeof(struct can_frame))
562 			error = EINVAL;
563 		break;
564 	case SIOCADDMULTI:
565 	case SIOCDELMULTI:
566 		error = EAFNOSUPPORT;
567 		break;
568 	default:
569 		error = ifioctl_common(ifp, cmd, data);
570 		if (error == 0) {
571 			if ((ifp->if_flags & IFF_UP) != 0 &&
572 			    (ifp->if_flags & IFF_RUNNING) == 0) {
573 				error = sunxi_can_ifup(sc);
574 				if (error) {
575 					ifp->if_flags &= ~IFF_UP;
576 				}
577 			} else if ((ifp->if_flags & IFF_UP) == 0 &&
578 			    (ifp->if_flags & IFF_RUNNING) != 0) {
579 				sunxi_can_ifdown(sc);
580 			}
581 		}
582 		break;
583 	}
584 
585 	mutex_exit(&sc->sc_intr_lock);
586 	return error;
587 }
588 
589 void
590 sunxi_can_ifwatchdog(struct ifnet *ifp)
591 {
592 	struct sunxi_can_softc * const sc = ifp->if_softc;
593 	printf("%s: watchdog timeout\n", device_xname(sc->sc_dev));
594 
595 	mutex_enter(&sc->sc_intr_lock);
596 	printf("irq 0x%x en 0x%x mode 0x%x status 0x%x timings 0x%x err 0x%x\n",
597 	    sunxi_can_read(sc, SUNXI_CAN_INT_REG),
598 	    sunxi_can_read(sc, SUNXI_CAN_INTE_REG),
599 	    sunxi_can_read(sc, SUNXI_CAN_MODSEL_REG),
600 	    sunxi_can_read(sc, SUNXI_CAN_STA_REG),
601 	    sunxi_can_read(sc, SUNXI_CAN_BUS_TIME_REG),
602 	    sunxi_can_read(sc, SUNXI_CAN_REC_REG));
603 	/* if there is a transmit in progress abort */
604 	if (sunxi_can_tx_abort(sc)) {
605 		if_statinc(ifp, if_oerrors);
606 	}
607 	mutex_exit(&sc->sc_intr_lock);
608 }
609 
610 static void
611 sunxi_can_enter_reset(struct sunxi_can_softc *sc)
612 {
613 	int i;
614 	uint32_t val;
615 
616 	for (i = 0; i < 1000; i++) {
617 		val = sunxi_can_read(sc, SUNXI_CAN_MODSEL_REG);
618 		val |= SUNXI_CAN_MODSEL_RST;
619 		sunxi_can_write(sc, SUNXI_CAN_MODSEL_REG, val);
620 		val = sunxi_can_read(sc, SUNXI_CAN_MODSEL_REG);
621 		if (val & SUNXI_CAN_MODSEL_RST)
622 			return;
623 	}
624 	printf("%s: couldn't enter reset mode\n", device_xname(sc->sc_dev));
625 }
626 
627 static void
628 sunxi_can_exit_reset(struct sunxi_can_softc *sc)
629 {
630 	int i;
631 	uint32_t val;
632 
633 	for (i = 0; i < 1000; i++) {
634 		val = sunxi_can_read(sc, SUNXI_CAN_MODSEL_REG);
635 		val &= ~SUNXI_CAN_MODSEL_RST;
636 		sunxi_can_write(sc, SUNXI_CAN_MODSEL_REG, val);
637 		val = sunxi_can_read(sc, SUNXI_CAN_MODSEL_REG);
638 		if ((val & SUNXI_CAN_MODSEL_RST) == 0)
639 			return;
640 	}
641 	printf("%s: couldn't leave reset mode\n", device_xname(sc->sc_dev));
642 }
643