xref: /netbsd-src/sys/arch/arm/sunxi/sunxi_can.c (revision aef5eb5f59cdfe8314f1b5f78ac04eb144e44010)
1 /*	$NetBSD: sunxi_can.c,v 1.12 2022/09/27 06:14:13 skrll 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 1.12 2022/09/27 06:14:13 skrll 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 static void sunxi_can_ifdown(struct sunxi_can_softc * const);
105 static int sunxi_can_ifup(struct sunxi_can_softc * const);
106 
107 CFATTACH_DECL_NEW(sunxi_can, sizeof(struct sunxi_can_softc),
108 	sunxi_can_match, sunxi_can_attach, NULL, NULL);
109 
110 static inline uint32_t
111 sunxi_can_read(struct sunxi_can_softc *sc, bus_size_t o)
112 {
113 	return bus_space_read_4(sc->sc_bst, sc->sc_bsh, o);
114 }
115 
116 static inline void
117 sunxi_can_write(struct sunxi_can_softc *sc, bus_size_t o, uint32_t v)
118 {
119 	return bus_space_write_4(sc->sc_bst, sc->sc_bsh, o, v);
120 }
121 
122 static int
123 sunxi_can_match(device_t parent, cfdata_t cf, void *aux)
124 {
125 	struct fdt_attach_args * const faa = aux;
126 
127 	return of_compatible_match(faa->faa_phandle, compat_data);
128 }
129 
130 static void
131 sunxi_can_attach(device_t parent, device_t self, void *aux)
132 {
133 	struct sunxi_can_softc * const sc = device_private(self);
134 	struct fdt_attach_args * const faa = aux;
135 	struct ifnet *ifp;
136 	const int phandle = faa->faa_phandle;
137 	bus_addr_t addr;
138 	bus_size_t size;
139 	char intrstr[128];
140 	struct clk *clk;
141 	struct fdtbus_reset *rst;
142 
143 	sc->sc_dev = self;
144 	mutex_init(&sc->sc_intr_lock, MUTEX_DEFAULT, IPL_NET);
145 
146 	sc->sc_bst = faa->faa_bst;
147 	if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
148 		aprint_error(": couldn't get registers\n");
149 		return;
150 	}
151 
152 	if (bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh) != 0) {
153 		aprint_error(": couldn't map registers\n");
154 		return;
155 	}
156 
157 	if (!fdtbus_intr_str(phandle, 0, intrstr, sizeof(intrstr))) {
158 		aprint_error(": failed to decode interrupt\n");
159 		return;
160 	}
161 
162 	if ((clk = fdtbus_clock_get_index(phandle, 0)) != NULL) {
163 		if (clk_enable(clk) != 0) {
164 			aprint_error(": couldn't enable clock\n");
165 			return;
166 		}
167 	}
168 
169 	if ((rst = fdtbus_reset_get_index(phandle, 0)) != NULL) {
170 		if (fdtbus_reset_deassert(rst) != 0) {
171 			aprint_error(": couldn't de-assert reset\n");
172 			return;
173 		}
174 	}
175 
176 	sc->sc_timecaps.cltc_prop_min = 0;
177 	sc->sc_timecaps.cltc_prop_max = 0;
178 	sc->sc_timecaps.cltc_ps1_min = 1;
179 	sc->sc_timecaps.cltc_ps1_max = 16;
180 	sc->sc_timecaps.cltc_ps2_min = 1;
181 	sc->sc_timecaps.cltc_ps2_max = 8;
182 	sc->sc_timecaps.cltc_sjw_max = 4;
183 	sc->sc_timecaps.cltc_brp_min = 1;
184 	sc->sc_timecaps.cltc_brp_max = 64;
185 	sc->sc_timecaps.cltc_brp_inc = 1;
186 	sc->sc_timecaps.cltc_clock_freq = clk_get_rate(clk);
187 	sc->sc_timecaps.cltc_linkmode_caps =
188 	    CAN_LINKMODE_3SAMPLES | CAN_LINKMODE_LISTENONLY |
189 	    CAN_LINKMODE_LOOPBACK;
190 	can_ifinit_timings(&sc->sc_cansc);
191 	sc->sc_timings.clt_prop = 0;
192 	sc->sc_timings.clt_sjw = 1;
193 
194 	aprint_naive("\n");
195 	aprint_normal(": CAN bus controller\n");
196 	aprint_debug_dev(self, ": clock freq %d\n",
197 	    sc->sc_timecaps.cltc_clock_freq);
198 
199 	sunxi_can_enter_reset(sc);
200 	/*
201 	 * Disable and then clear all interrupts
202 	 */
203 	sunxi_can_write(sc, SUNXI_CAN_INTE_REG, 0);
204 	sunxi_can_write(sc, SUNXI_CAN_INT_REG,
205 	    sunxi_can_read(sc, SUNXI_CAN_INT_REG));
206 
207 	sc->sc_ih = fdtbus_intr_establish_xname(phandle, 0, IPL_NET, 0,
208 	    sunxi_can_intr, sc, device_xname(self));
209 	if (sc->sc_ih == NULL) {
210 		aprint_error_dev(self, "failed to establish interrupt on %s\n",
211 		    intrstr);
212 		return;
213 	}
214 	aprint_normal_dev(self, "interrupting on %s\n", intrstr);
215 
216 	ifp = if_alloc(IFT_OTHER);
217 	sc->sc_ifp = ifp;
218 	strlcpy(ifp->if_xname, device_xname(self), IFNAMSIZ);
219 	ifp->if_softc = sc;
220 	ifp->if_capabilities = 0;
221 	ifp->if_flags = 0;
222 	ifp->if_start = sunxi_can_ifstart;
223 	ifp->if_ioctl = sunxi_can_ifioctl;
224 	ifp->if_watchdog = sunxi_can_ifwatchdog;
225 
226 	/*
227 	 * Attach the interface.
228 	 */
229 	can_ifattach(ifp);
230 	if_deferred_start_init(ifp, NULL);
231 	bpf_mtap_softint_init(ifp);
232 	rnd_attach_source(&sc->sc_rnd_source, device_xname(self),
233 	    RND_TYPE_NET, RND_FLAG_DEFAULT);
234 #ifdef MBUFTRACE
235 	ifp->if_mowner = kmem_zalloc(sizeof(*ifp->if_mowner), KM_SLEEP);
236 	strlcpy(ifp->if_mowner->mo_name, ifp->if_xname,
237 		sizeof(ifp->if_mowner->mo_name));
238 	MOWNER_ATTACH(ifp->if_mowner);
239 #endif
240 }
241 
242 static void
243 sunxi_can_rx_intr(struct sunxi_can_softc *sc)
244 {
245 	uint32_t reg0v;
246 	struct mbuf *m;
247 	struct ifnet  *ifp = sc->sc_ifp;
248 	struct can_frame *cf;
249 	int dlc;
250 	int regd, i;
251 
252 	KASSERT(mutex_owned(&sc->sc_intr_lock));
253 	reg0v = sunxi_can_read(sc, SUNXI_CAN_TXBUF0_REG);
254 	dlc = reg0v & SUNXI_CAN_TXBUF0_DL;
255 
256 	if (dlc > CAN_MAX_DLC) {
257 		if_statinc(ifp, if_ierrors);
258 		sunxi_can_write(sc, SUNXI_CAN_CMD_REG, SUNXI_CAN_CMD_REL_RX_BUF);
259 		return;
260 	}
261 
262 	m = m_gethdr(M_NOWAIT, MT_HEADER);
263 	if (m == NULL) {
264 		if_statinc(ifp, if_ierrors);
265 		sunxi_can_write(sc, SUNXI_CAN_CMD_REG, SUNXI_CAN_CMD_REL_RX_BUF);
266 		return;
267 	}
268 	cf = mtod(m, struct can_frame *);
269 	memset(cf, 0, sizeof(struct can_frame));
270 
271 	cf->can_dlc = dlc;
272 
273 	if (reg0v & SUNXI_CAN_TXBUF0_EFF) {
274 		cf->can_id =
275 		    (sunxi_can_read(sc, SUNXI_CAN_TXBUF1_REG) << 21) |
276 		    (sunxi_can_read(sc, SUNXI_CAN_TXBUF2_REG) << 13) |
277 		    (sunxi_can_read(sc, SUNXI_CAN_TXBUF3_REG) << 5) |
278 		    ((sunxi_can_read(sc, SUNXI_CAN_TXBUF4_REG) >> 3) & 0x1f);
279 		cf->can_id |= CAN_EFF_FLAG;
280 		regd = SUNXI_CAN_TXBUF5_REG;
281 	} else {
282 		cf->can_id =
283 		    (sunxi_can_read(sc, SUNXI_CAN_TXBUF1_REG) << 3) |
284 		    ((sunxi_can_read(sc, SUNXI_CAN_TXBUF2_REG) << 5) & 0x7);
285 		regd = SUNXI_CAN_TXBUF3_REG;
286 	}
287 	if (reg0v & SUNXI_CAN_TXBUF0_RTR) {
288 		cf->can_id |= CAN_RTR_FLAG;
289 	} else {
290 		for (i = 0; i < cf->can_dlc; i++) {
291 			cf->data[i] = sunxi_can_read(sc, regd + i * 4);
292 		}
293 	}
294 	sunxi_can_write(sc, SUNXI_CAN_CMD_REG, SUNXI_CAN_CMD_REL_RX_BUF);
295 	m->m_len = m->m_pkthdr.len = CAN_MTU;
296 	if_statadd(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 		if_statadd2(ifp, if_obytes, m->m_len, if_opackets, 1);
311 		can_mbuf_tag_clean(m);
312 		m_set_rcvif(m, ifp);
313 		can_input(ifp, m); /* loopback */
314 		sc->sc_m_transmit = NULL;
315 		ifp->if_timer = 0;
316 	}
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 as appropriate.
331 		 */
332 		sunxi_can_write(sc, SUNXI_CAN_CMD_REG, SUNXI_CAN_CMD_ABT_REQ);
333 		return 1;
334 	}
335 	return 0;
336 }
337 
338 static void
339 sunxi_can_err_intr(struct sunxi_can_softc *sc, uint32_t irq, uint32_t sts)
340 {
341 	struct ifnet * const ifp = sc->sc_ifp;
342 	KASSERT(mutex_owned(&sc->sc_intr_lock));
343 	int txerr = 0;
344 	uint32_t reg;
345 
346 	if (irq & SUNXI_CAN_INT_DATA_OR) {
347 		if_statinc(ifp, if_ierrors);
348 		sunxi_can_ifdown(sc);
349 		sunxi_can_write(sc, SUNXI_CAN_CMD_REG, SUNXI_CAN_CMD_CLR_OR);
350 		sunxi_can_ifup(sc);
351 	}
352 	if (irq & SUNXI_CAN_INT_ERR) {
353 		reg = sunxi_can_read(sc, SUNXI_CAN_REC_REG);
354 		printf("%s: ERR interrupt status 0x%x counters 0x%x\n",
355 		    device_xname(sc->sc_dev), sts, reg);
356 
357 	}
358 	if (irq & SUNXI_CAN_INT_BERR) {
359 		if (sts & SUNXI_CAN_STA_TX)
360 			txerr++;
361 		if (sts & SUNXI_CAN_STA_RX)
362 			if_statinc(ifp, if_ierrors);
363 	}
364 	if (irq & SUNXI_CAN_INT_ERR_PASSIVE) {
365 		printf("%s: PASSV interrupt status 0x%x\n",
366 		    device_xname(sc->sc_dev), sts);
367 	}
368 	if (irq & SUNXI_CAN_INT_ARB_LOST) {
369 		txerr++;
370 	}
371 	if (txerr) {
372 		if_statadd(ifp, if_oerrors, txerr);
373 		(void) sunxi_can_tx_abort(sc);
374 	}
375 }
376 
377 int
378 sunxi_can_intr(void *arg)
379 {
380 	struct sunxi_can_softc * const sc = arg;
381 	int rv = 0;
382 	int irq;
383 
384 	mutex_enter(&sc->sc_intr_lock);
385 
386 	while ((irq = sunxi_can_read(sc, SUNXI_CAN_INT_REG)) != 0) {
387 		uint32_t sts = sunxi_can_read(sc, SUNXI_CAN_STA_REG);
388 		rv = 1;
389                 rnd_add_uint32(&sc->sc_rnd_source, irq);
390 
391 		if ((irq & (SUNXI_CAN_INT_RX_FLAG | SUNXI_CAN_INT_DATA_OR)) ==
392 		    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 			 * Don't write SUNXI_CAN_INT_RX_FLAG to the interrupt
399 			 * register, this may clear the RX pending flag
400 			 * while there is indeed a packet pending.
401 			 * Reading packets should have cleared the RX interrupt,
402 			 * so just restart the loop and re-read the interrupt
403 			 * register. In the common case irq will now be 0.
404 			 */
405 			continue;
406 		}
407 		if (irq & SUNXI_CAN_INT_TX_FLAG) {
408 			sunxi_can_tx_intr(sc);
409 		}
410 		if (irq & SUNXI_CAN_INT_ALLERRS) {
411 			sunxi_can_err_intr(sc, irq, sts);
412 		}
413 		sunxi_can_write(sc, SUNXI_CAN_INT_REG, irq);
414 	}
415 	mutex_exit(&sc->sc_intr_lock);
416 
417 	return rv;
418 }
419 
420 void
421 sunxi_can_ifstart(struct ifnet *ifp)
422 {
423 	struct sunxi_can_softc * const sc = ifp->if_softc;
424 	struct mbuf *m;
425 	struct can_frame *cf;
426 	int regd;
427 	uint32_t reg0val;
428 	int i;
429 
430 	mutex_enter(&sc->sc_intr_lock);
431 	if (sc->sc_m_transmit != NULL)
432 		goto out;
433 
434 	IF_DEQUEUE(&ifp->if_snd, m);
435 
436 	if (m == NULL)
437 		goto out;
438 
439 	MCLAIM(m, ifp->if_mowner);
440 	sc->sc_m_transmit = m;
441 
442 	KASSERT((m->m_flags & M_PKTHDR) != 0);
443 	KASSERT(m->m_len == m->m_pkthdr.len);
444 
445 	cf = mtod(m, struct can_frame *);
446 	reg0val = cf->can_dlc & SUNXI_CAN_TXBUF0_DL;
447 	if (cf->can_id & CAN_RTR_FLAG)
448 		reg0val |= SUNXI_CAN_TXBUF0_RTR;
449 
450 	if (cf->can_id & CAN_EFF_FLAG) {
451 		reg0val |= SUNXI_CAN_TXBUF0_EFF;
452 		sunxi_can_write(sc, SUNXI_CAN_TXBUF1_REG,
453 		    (cf->can_id >> 21) & 0xff);
454 		sunxi_can_write(sc, SUNXI_CAN_TXBUF2_REG,
455 		    (cf->can_id >> 13) & 0xff);
456 		sunxi_can_write(sc, SUNXI_CAN_TXBUF3_REG,
457 		    (cf->can_id >> 5) & 0xff);
458 		sunxi_can_write(sc, SUNXI_CAN_TXBUF4_REG,
459 		    (cf->can_id << 3) & 0xf8);
460 		regd = SUNXI_CAN_TXBUF5_REG;
461 	} else {
462 		sunxi_can_write(sc, SUNXI_CAN_TXBUF1_REG,
463 		    (cf->can_id >> 3) & 0xff);
464 		sunxi_can_write(sc, SUNXI_CAN_TXBUF2_REG,
465 		    (cf->can_id << 5) & 0xe0);
466 		regd = SUNXI_CAN_TXBUF3_REG;
467 	}
468 
469 	for (i = 0; i < cf->can_dlc; i++) {
470 		sunxi_can_write(sc, regd + i * 4, cf->data[i]);
471 	}
472 	sunxi_can_write(sc, SUNXI_CAN_TXBUF0_REG, reg0val);
473 
474 	if (sc->sc_linkmodes & CAN_LINKMODE_LOOPBACK) {
475 		sunxi_can_write(sc, SUNXI_CAN_CMD_REG,
476 			SUNXI_CAN_CMD_TANS_REQ | SUNXI_CAN_CMD_SELF_REQ);
477 	} else {
478 		sunxi_can_write(sc, SUNXI_CAN_CMD_REG, SUNXI_CAN_CMD_TANS_REQ);
479 	}
480 	ifp->if_timer = 5;
481 	can_bpf_mtap(ifp, m, 0);
482 out:
483 	mutex_exit(&sc->sc_intr_lock);
484 }
485 
486 static int
487 sunxi_can_ifup(struct sunxi_can_softc * const sc)
488 {
489 	uint32_t reg;
490 
491 	/* setup timings and mode - has to be done in reset */
492 	reg = SUNXI_CAN_MODSEL_RST;
493 	if (sc->sc_linkmodes & CAN_LINKMODE_LISTENONLY)
494 		reg |= SUNXI_CAN_MODSEL_LST_ONLY;
495 
496 	if (sc->sc_linkmodes & CAN_LINKMODE_LOOPBACK)
497 		reg |= SUNXI_CAN_MODSEL_LB_MOD;
498 
499 	sunxi_can_write(sc, SUNXI_CAN_MODSEL_REG, reg);
500 
501 	reg = 0;
502 	if (sc->sc_timings.clt_prop != 0)
503 		return EINVAL;
504 
505 	if (sc->sc_timings.clt_brp > sc->sc_timecaps.cltc_brp_max ||
506 	   sc->sc_timings.clt_brp < sc->sc_timecaps.cltc_brp_min)
507 		return EINVAL;
508 	reg |= (sc->sc_timings.clt_brp - 1) << 0;
509 
510 	if (sc->sc_timings.clt_ps1 > sc->sc_timecaps.cltc_ps1_max ||
511 	   sc->sc_timings.clt_ps1 < sc->sc_timecaps.cltc_ps1_min)
512 		return EINVAL;
513 	reg |= (sc->sc_timings.clt_ps1 - 1) << 16;
514 
515 	if (sc->sc_timings.clt_ps2 > sc->sc_timecaps.cltc_ps2_max ||
516 	   sc->sc_timings.clt_ps2 < sc->sc_timecaps.cltc_ps2_min)
517 		return EINVAL;
518 	reg |= (sc->sc_timings.clt_ps2 - 1) << 20;
519 
520 	if (sc->sc_timings.clt_sjw > sc->sc_timecaps.cltc_sjw_max ||
521 	   sc->sc_timings.clt_sjw < 1)
522 		return EINVAL;
523 	reg |= (sc->sc_timings.clt_sjw - 1) << 14;
524 
525 	if (sc->sc_linkmodes & CAN_LINKMODE_3SAMPLES)
526 		reg |= SUNXI_CAN_BUS_TIME_SAM;
527 
528 	sunxi_can_write(sc, SUNXI_CAN_BUS_TIME_REG, reg);
529 
530 	/* set filters to accept all frames */
531 	sunxi_can_write(sc, SUNXI_CAN_ACPC, 0x00000000);
532 	sunxi_can_write(sc, SUNXI_CAN_ACPM, 0xffffffff);
533 
534 	/* clear errors counter */
535 	sunxi_can_write(sc, SUNXI_CAN_REC_REG, 0);
536 
537 	/* leave reset mode and enable interrupts */
538 	sunxi_can_exit_reset(sc);
539 	sunxi_can_write(sc, SUNXI_CAN_INTE_REG,
540 	    SUNXI_CAN_INT_TX_FLAG | SUNXI_CAN_INT_RX_FLAG | SUNXI_CAN_INT_ALLERRS);
541 	sc->sc_ifp->if_flags |= IFF_RUNNING;
542 	return 0;
543 }
544 
545 static void
546 sunxi_can_ifdown(struct sunxi_can_softc * const sc)
547 {
548 	sc->sc_ifp->if_flags &= ~IFF_RUNNING;
549 	sc->sc_ifp->if_timer = 0;
550 	sunxi_can_enter_reset(sc);
551 	sunxi_can_write(sc, SUNXI_CAN_INTE_REG, 0);
552 	sunxi_can_write(sc, SUNXI_CAN_INT_REG,
553 	    sunxi_can_read(sc, SUNXI_CAN_INT_REG));
554 }
555 
556 static int
557 sunxi_can_ifioctl(struct ifnet *ifp, u_long cmd, void *data)
558 {
559 	struct sunxi_can_softc * const sc = ifp->if_softc;
560 	struct ifreq *ifr = (struct ifreq *)data;
561 	int error = 0;
562 
563 	mutex_enter(&sc->sc_intr_lock);
564 
565 	switch (cmd) {
566 	case SIOCINITIFADDR:
567 		error = EAFNOSUPPORT;
568 		break;
569 	case SIOCSIFMTU:
570 		if ((unsigned)ifr->ifr_mtu != sizeof(struct can_frame))
571 			error = EINVAL;
572 		break;
573 	case SIOCADDMULTI:
574 	case SIOCDELMULTI:
575 		error = EAFNOSUPPORT;
576 		break;
577 	default:
578 		error = ifioctl_common(ifp, cmd, data);
579 		if (error == 0) {
580 			if ((ifp->if_flags & IFF_UP) != 0 &&
581 			    (ifp->if_flags & IFF_RUNNING) == 0) {
582 				error = sunxi_can_ifup(sc);
583 				if (error) {
584 					ifp->if_flags &= ~IFF_UP;
585 				}
586 			} else if ((ifp->if_flags & IFF_UP) == 0 &&
587 			    (ifp->if_flags & IFF_RUNNING) != 0) {
588 				sunxi_can_ifdown(sc);
589 			}
590 		}
591 		break;
592 	}
593 
594 	mutex_exit(&sc->sc_intr_lock);
595 	return error;
596 }
597 
598 void
599 sunxi_can_ifwatchdog(struct ifnet *ifp)
600 {
601 	struct sunxi_can_softc * const sc = ifp->if_softc;
602 	printf("%s: watchdog timeout\n", device_xname(sc->sc_dev));
603 
604 	mutex_enter(&sc->sc_intr_lock);
605 	printf("irq 0x%x en 0x%x mode 0x%x status 0x%x timings 0x%x err 0x%x\n",
606 	    sunxi_can_read(sc, SUNXI_CAN_INT_REG),
607 	    sunxi_can_read(sc, SUNXI_CAN_INTE_REG),
608 	    sunxi_can_read(sc, SUNXI_CAN_MODSEL_REG),
609 	    sunxi_can_read(sc, SUNXI_CAN_STA_REG),
610 	    sunxi_can_read(sc, SUNXI_CAN_BUS_TIME_REG),
611 	    sunxi_can_read(sc, SUNXI_CAN_REC_REG));
612 	/* if there is a transmit in progress abort */
613 	if (sunxi_can_tx_abort(sc)) {
614 		if_statinc(ifp, if_oerrors);
615 	}
616 	mutex_exit(&sc->sc_intr_lock);
617 }
618 
619 static void
620 sunxi_can_enter_reset(struct sunxi_can_softc *sc)
621 {
622 	int i;
623 	uint32_t val;
624 
625 	for (i = 0; i < 1000; i++) {
626 		val = sunxi_can_read(sc, SUNXI_CAN_MODSEL_REG);
627 		val |= SUNXI_CAN_MODSEL_RST;
628 		sunxi_can_write(sc, SUNXI_CAN_MODSEL_REG, val);
629 		val = sunxi_can_read(sc, SUNXI_CAN_MODSEL_REG);
630 		if (val & SUNXI_CAN_MODSEL_RST)
631 			return;
632 	}
633 	printf("%s: couldn't enter reset mode\n", device_xname(sc->sc_dev));
634 }
635 
636 static void
637 sunxi_can_exit_reset(struct sunxi_can_softc *sc)
638 {
639 	int i;
640 	uint32_t val;
641 
642 	for (i = 0; i < 1000; i++) {
643 		val = sunxi_can_read(sc, SUNXI_CAN_MODSEL_REG);
644 		val &= ~SUNXI_CAN_MODSEL_RST;
645 		sunxi_can_write(sc, SUNXI_CAN_MODSEL_REG, val);
646 		val = sunxi_can_read(sc, SUNXI_CAN_MODSEL_REG);
647 		if ((val & SUNXI_CAN_MODSEL_RST) == 0)
648 			return;
649 	}
650 	printf("%s: couldn't leave reset mode\n", device_xname(sc->sc_dev));
651 }
652