xref: /netbsd-src/sys/arch/arm/sunxi/sunxi_can.c (revision c38e7cc395b1472a774ff828e46123de44c628e9)
1 /*	$NetBSD: sunxi_can.c,v 1.1 2018/03/07 20:55:31 bouyer 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 1.1 2018/03/07 20:55:31 bouyer 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 of_compat_data compat_data[] = {
89 	{"allwinner,sun4i-a10-can", 0},
90 	{NULL}
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_match_compat_data(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(phandle, 0, IPL_NET, 0,
206 	    sunxi_can_intr, sc);
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 		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 		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 	ifp->if_ipackets++;
296 	ifp->if_ibytes += m->m_len;
297 	m_set_rcvif(m, ifp);
298 	can_bpf_mtap(ifp, m, 1);
299 	can_input(ifp, m);
300 }
301 
302 static void
303 sunxi_can_tx_intr(struct sunxi_can_softc *sc)
304 {
305 	struct ifnet * const ifp = sc->sc_ifp;
306 	struct mbuf *m;
307 
308 	KASSERT(mutex_owned(&sc->sc_intr_lock));
309 	if ((m = sc->sc_m_transmit) != NULL) {
310 		ifp->if_obytes += m->m_len;
311 		ifp->if_opackets++;
312 		can_mbuf_tag_clean(m);
313 		m_set_rcvif(m, ifp);
314 		can_input(ifp, m); /* loopback */
315 		sc->sc_m_transmit = NULL;
316 		ifp->if_timer = 0;
317 	}
318 	ifp->if_flags &= ~IFF_OACTIVE;
319 	if_schedule_deferred_start(ifp);
320 }
321 
322 static int
323 sunxi_can_tx_abort(struct sunxi_can_softc *sc)
324 {
325 	KASSERT(mutex_owned(&sc->sc_intr_lock));
326 	if (sc->sc_m_transmit) {
327 		m_freem(sc->sc_m_transmit);
328 		sc->sc_m_transmit = NULL;
329 		sc->sc_ifp->if_timer = 0;
330 		/*
331 		 * the transmit abort will trigger a TX interrupt
332 		 * which will restart the queue or cleae OACTIVE,
333 		 * as appropriate
334 		 */
335 		sunxi_can_write(sc, SUNXI_CAN_CMD_REG, SUNXI_CAN_CMD_ABT_REQ);
336 		return 1;
337 	}
338 	return 0;
339 }
340 
341 static void
342 sunxi_can_err_intr(struct sunxi_can_softc *sc, uint32_t irq, uint32_t sts)
343 {
344 	struct ifnet * const ifp = sc->sc_ifp;
345 	KASSERT(mutex_owned(&sc->sc_intr_lock));
346 	int txerr = 0;
347 	uint32_t reg;
348 
349 	if (irq & SUNXI_CAN_INT_DATA_OR) {
350 		ifp->if_ierrors++;
351 		sunxi_can_write(sc, SUNXI_CAN_CMD_REG, SUNXI_CAN_CMD_CLR_OR);
352 	}
353 	if (irq & SUNXI_CAN_INT_ERR) {
354 		reg = sunxi_can_read(sc, SUNXI_CAN_REC_REG);
355 		printf("%s: ERR interrupt status 0x%x counters 0x%x\n",
356 		    device_xname(sc->sc_dev), sts, reg);
357 
358 	}
359 	if (irq & SUNXI_CAN_INT_BERR) {
360 		if (sts & SUNXI_CAN_STA_TX)
361 			txerr++;
362 		if (sts & SUNXI_CAN_STA_RX)
363 			ifp->if_ierrors++;
364 	}
365 	if (irq & SUNXI_CAN_INT_ERR_PASSIVE) {
366 		printf("%s: PASSV interrupt status 0x%x\n",
367 		    device_xname(sc->sc_dev), sts);
368 	}
369 	if (irq & SUNXI_CAN_INT_ARB_LOST) {
370 		txerr++;
371 	}
372 	if (txerr) {
373 		ifp->if_oerrors += txerr;
374 		(void) sunxi_can_tx_abort(sc);
375 	}
376 }
377 
378 int
379 sunxi_can_intr(void *arg)
380 {
381 	struct sunxi_can_softc * const sc = arg;
382 	int rv = 0;
383 	int irq;
384 
385 	mutex_enter(&sc->sc_intr_lock);
386 
387 	while ((irq = sunxi_can_read(sc, SUNXI_CAN_INT_REG)) != 0) {
388 		uint32_t sts = sunxi_can_read(sc, SUNXI_CAN_STA_REG);
389 		rv = 1;
390 
391 		if (irq & SUNXI_CAN_INT_TX_FLAG) {
392 			sunxi_can_tx_intr(sc);
393 		}
394 		if (irq & SUNXI_CAN_INT_RX_FLAG) {
395 			while (sts & SUNXI_CAN_STA_RX_RDY) {
396 				sunxi_can_rx_intr(sc);
397 				sts = sunxi_can_read(sc, SUNXI_CAN_STA_REG);
398 			}
399 		}
400 		if (irq & SUNXI_CAN_INT_ALLERRS) {
401 			sunxi_can_err_intr(sc, irq, sts);
402 		}
403 		sunxi_can_write(sc, SUNXI_CAN_INT_REG, irq);
404                 rnd_add_uint32(&sc->sc_rnd_source, irq);
405 
406 	}
407 	mutex_exit(&sc->sc_intr_lock);
408 
409 	return rv;
410 }
411 
412 void
413 sunxi_can_ifstart(struct ifnet *ifp)
414 {
415 	struct sunxi_can_softc * const sc = ifp->if_softc;
416 	struct mbuf *m;
417 	struct can_frame *cf;
418 	int regd;
419 	uint32_t reg0val;
420 	int i;
421 
422 	mutex_enter(&sc->sc_intr_lock);
423 	if (ifp->if_flags & IFF_OACTIVE)
424 		goto out;
425 
426 	IF_DEQUEUE(&ifp->if_snd, m);
427 
428 	if (m == NULL)
429 		goto out;
430 
431 	MCLAIM(m, ifp->if_mowner);
432 	sc->sc_m_transmit = m;
433 
434 	KASSERT((m->m_flags & M_PKTHDR) != 0);
435 	KASSERT(m->m_len == m->m_pkthdr.len);
436 
437 	cf = mtod(m, struct can_frame *);
438 	reg0val = cf->can_dlc & SUNXI_CAN_TXBUF0_DL;
439 	if (cf->can_id & CAN_RTR_FLAG)
440 		reg0val |= SUNXI_CAN_TXBUF0_RTR;
441 
442 	if (cf->can_id & CAN_EFF_FLAG) {
443 		reg0val |= SUNXI_CAN_TXBUF0_EFF;
444 		sunxi_can_write(sc, SUNXI_CAN_TXBUF1_REG,
445 		    (cf->can_id >> 21) & 0xff);
446 		sunxi_can_write(sc, SUNXI_CAN_TXBUF2_REG,
447 		    (cf->can_id >> 13) & 0xff);
448 		sunxi_can_write(sc, SUNXI_CAN_TXBUF3_REG,
449 		    (cf->can_id >> 5) & 0xff);
450 		sunxi_can_write(sc, SUNXI_CAN_TXBUF4_REG,
451 		    (cf->can_id << 3) & 0xf8);
452 		regd = SUNXI_CAN_TXBUF5_REG;
453 	} else {
454 		sunxi_can_write(sc, SUNXI_CAN_TXBUF1_REG,
455 		    (cf->can_id >> 3) & 0xff);
456 		sunxi_can_write(sc, SUNXI_CAN_TXBUF2_REG,
457 		    (cf->can_id << 5) & 0xe0);
458 		regd = SUNXI_CAN_TXBUF3_REG;
459 	}
460 
461 	for (i = 0; i < cf->can_dlc; i++) {
462 		sunxi_can_write(sc, regd + i * 4, cf->data[i]);
463 	}
464 	sunxi_can_write(sc, SUNXI_CAN_TXBUF0_REG, reg0val);
465 
466 	if (sc->sc_linkmodes & CAN_LINKMODE_LOOPBACK) {
467 		sunxi_can_write(sc, SUNXI_CAN_CMD_REG,
468 			SUNXI_CAN_CMD_TANS_REQ | SUNXI_CAN_CMD_SELF_REQ);
469 	} else {
470 		sunxi_can_write(sc, SUNXI_CAN_CMD_REG, SUNXI_CAN_CMD_TANS_REQ);
471 	}
472 	ifp->if_flags |= IFF_OACTIVE;
473 	ifp->if_timer = 5;
474 	can_bpf_mtap(ifp, m, 0);
475 out:
476 	mutex_exit(&sc->sc_intr_lock);
477 }
478 
479 static int
480 sunxi_can_ifup(struct sunxi_can_softc * const sc)
481 {
482 	uint32_t reg;
483 
484 	/* setup timings and mode - has to be done in reset */
485 	reg = SUNXI_CAN_MODSEL_RST;
486 	if (sc->sc_linkmodes & CAN_LINKMODE_LISTENONLY)
487 		reg |= SUNXI_CAN_MODSEL_LST_ONLY;
488 
489 	if (sc->sc_linkmodes & CAN_LINKMODE_LOOPBACK)
490 		reg |= SUNXI_CAN_MODSEL_LB_MOD;
491 
492 	sunxi_can_write(sc, SUNXI_CAN_MODSEL_REG, reg);
493 
494 	reg = 0;
495 	if (sc->sc_timings.clt_prop != 0)
496 		return EINVAL;
497 
498 	if (sc->sc_timings.clt_brp > sc->sc_timecaps.cltc_brp_max ||
499 	   sc->sc_timings.clt_brp < sc->sc_timecaps.cltc_brp_min)
500 		return EINVAL;
501 	reg |= (sc->sc_timings.clt_brp - 1) << 0;
502 
503 	if (sc->sc_timings.clt_ps1 > sc->sc_timecaps.cltc_ps1_max ||
504 	   sc->sc_timings.clt_ps1 < sc->sc_timecaps.cltc_ps1_min)
505 		return EINVAL;
506 	reg |= (sc->sc_timings.clt_ps1 - 1) << 16;
507 
508 	if (sc->sc_timings.clt_ps2 > sc->sc_timecaps.cltc_ps2_max ||
509 	   sc->sc_timings.clt_ps2 < sc->sc_timecaps.cltc_ps2_min)
510 		return EINVAL;
511 	reg |= (sc->sc_timings.clt_ps2 - 1) << 20;
512 
513 	if (sc->sc_timings.clt_sjw > sc->sc_timecaps.cltc_sjw_max ||
514 	   sc->sc_timings.clt_sjw < 1)
515 		return EINVAL;
516 	reg |= (sc->sc_timings.clt_sjw - 1) << 14;
517 
518 	if (sc->sc_linkmodes & CAN_LINKMODE_3SAMPLES)
519 		reg |= SUNXI_CAN_BUS_TIME_SAM;
520 
521 	sunxi_can_write(sc, SUNXI_CAN_BUS_TIME_REG, reg);
522 
523 	/* set filters to accept all frames */
524 	sunxi_can_write(sc, SUNXI_CAN_ACPC, 0x00000000);
525 	sunxi_can_write(sc, SUNXI_CAN_ACPM, 0xffffffff);
526 
527 	/* clear errors counter */
528 	sunxi_can_write(sc, SUNXI_CAN_REC_REG, 0);
529 
530 	/* leave reset mode and enable interrupts */
531 	sunxi_can_exit_reset(sc);
532 	sunxi_can_write(sc, SUNXI_CAN_INTE_REG,
533 	    SUNXI_CAN_INT_TX_FLAG | SUNXI_CAN_INT_RX_FLAG | SUNXI_CAN_INT_ALLERRS);
534 	sc->sc_ifp->if_flags |= IFF_RUNNING;
535 	return 0;
536 }
537 
538 static void
539 sunxi_can_ifdown(struct sunxi_can_softc * const sc)
540 {
541 	sc->sc_ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
542 	sc->sc_ifp->if_timer = 0;
543 	sunxi_can_enter_reset(sc);
544 	sunxi_can_write(sc, SUNXI_CAN_INTE_REG, 0);
545 	sunxi_can_write(sc, SUNXI_CAN_INT_REG,
546 	    sunxi_can_read(sc, SUNXI_CAN_INT_REG));
547 }
548 
549 static int
550 sunxi_can_ifioctl(struct ifnet *ifp, u_long cmd, void *data)
551 {
552 	struct sunxi_can_softc * const sc = ifp->if_softc;
553 	struct ifreq *ifr = (struct ifreq *)data;
554 	int error = 0;
555 
556 	mutex_enter(&sc->sc_intr_lock);
557 
558 	switch (cmd) {
559 	case SIOCINITIFADDR:
560 		error = EAFNOSUPPORT;
561 		break;
562 	case SIOCSIFMTU:
563 		if ((unsigned)ifr->ifr_mtu != sizeof(struct can_frame))
564 			error = EINVAL;
565 		break;
566 	case SIOCADDMULTI:
567 	case SIOCDELMULTI:
568 		error = EAFNOSUPPORT;
569 		break;
570 	default:
571 		error = ifioctl_common(ifp, cmd, data);
572 		if (error == 0) {
573 			if ((ifp->if_flags & IFF_UP) != 0 &&
574 			    (ifp->if_flags & IFF_RUNNING) == 0) {
575 				error = sunxi_can_ifup(sc);
576 				if (error) {
577 					ifp->if_flags &= ~IFF_UP;
578 				}
579 			} else if ((ifp->if_flags & IFF_UP) == 0 &&
580 			    (ifp->if_flags & IFF_RUNNING) != 0) {
581 				sunxi_can_ifdown(sc);
582 			}
583 		}
584 		break;
585 	}
586 
587 	mutex_exit(&sc->sc_intr_lock);
588 	return error;
589 }
590 
591 void
592 sunxi_can_ifwatchdog(struct ifnet *ifp)
593 {
594 	struct sunxi_can_softc * const sc = ifp->if_softc;
595 	printf("%s: watchdog timeout\n", device_xname(sc->sc_dev));
596 
597 	mutex_enter(&sc->sc_intr_lock);
598 	printf("irq 0x%x en 0x%x mode 0x%x status 0x%x timings 0x%x err 0x%x\n",
599 	    sunxi_can_read(sc, SUNXI_CAN_INT_REG),
600 	    sunxi_can_read(sc, SUNXI_CAN_INTE_REG),
601 	    sunxi_can_read(sc, SUNXI_CAN_MODSEL_REG),
602 	    sunxi_can_read(sc, SUNXI_CAN_STA_REG),
603 	    sunxi_can_read(sc, SUNXI_CAN_BUS_TIME_REG),
604 	    sunxi_can_read(sc, SUNXI_CAN_REC_REG));
605 	/* if there is a transmit in progress abort */
606 	if (sunxi_can_tx_abort(sc)) {
607 		ifp->if_oerrors++;
608 	}
609 	mutex_exit(&sc->sc_intr_lock);
610 }
611 
612 static void
613 sunxi_can_enter_reset(struct sunxi_can_softc *sc)
614 {
615 	int i;
616 	uint32_t val;
617 
618 	for (i = 0; i < 1000; i++) {
619 		val = sunxi_can_read(sc, SUNXI_CAN_MODSEL_REG);
620 		val |= SUNXI_CAN_MODSEL_RST;
621 		sunxi_can_write(sc, SUNXI_CAN_MODSEL_REG, val);
622 		val = sunxi_can_read(sc, SUNXI_CAN_MODSEL_REG);
623 		if (val & SUNXI_CAN_MODSEL_RST)
624 			return;
625 	}
626 	printf("%s: couldn't enter reset mode\n", device_xname(sc->sc_dev));
627 }
628 
629 static void
630 sunxi_can_exit_reset(struct sunxi_can_softc *sc)
631 {
632 	int i;
633 	uint32_t val;
634 
635 	for (i = 0; i < 1000; i++) {
636 		val = sunxi_can_read(sc, SUNXI_CAN_MODSEL_REG);
637 		val &= ~SUNXI_CAN_MODSEL_RST;
638 		sunxi_can_write(sc, SUNXI_CAN_MODSEL_REG, val);
639 		val = sunxi_can_read(sc, SUNXI_CAN_MODSEL_REG);
640 		if ((val & SUNXI_CAN_MODSEL_RST) == 0)
641 			return;
642 	}
643 	printf("%s: couldn't leave reset mode\n", device_xname(sc->sc_dev));
644 }
645