1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // mcp251xfd - Microchip MCP251xFD Family CAN controller driver
4 //
5 // Copyright (c) 2019, 2020 Pengutronix,
6 //                          Marc Kleine-Budde <kernel@pengutronix.de>
7 //
8 // Based on:
9 //
10 // CAN bus driver for Microchip 25XXFD CAN Controller with SPI Interface
11 //
12 // Copyright (c) 2019 Martin Sperl <kernel@martin.sperl.org>
13 //
14 
15 #include <linux/bitfield.h>
16 #include <linux/clk.h>
17 #include <linux/device.h>
18 #include <linux/module.h>
19 #include <linux/netdevice.h>
20 #include <linux/of.h>
21 #include <linux/of_device.h>
22 #include <linux/pm_runtime.h>
23 
24 #include <asm/unaligned.h>
25 
26 #include "mcp251xfd.h"
27 
28 #define DEVICE_NAME "mcp251xfd"
29 
30 static const struct mcp251xfd_devtype_data mcp251xfd_devtype_data_mcp2517fd = {
31 	.quirks = MCP251XFD_QUIRK_MAB_NO_WARN | MCP251XFD_QUIRK_CRC_REG |
32 		MCP251XFD_QUIRK_CRC_RX | MCP251XFD_QUIRK_CRC_TX |
33 		MCP251XFD_QUIRK_ECC,
34 	.model = MCP251XFD_MODEL_MCP2517FD,
35 };
36 
37 static const struct mcp251xfd_devtype_data mcp251xfd_devtype_data_mcp2518fd = {
38 	.quirks = MCP251XFD_QUIRK_CRC_REG | MCP251XFD_QUIRK_CRC_RX |
39 		MCP251XFD_QUIRK_CRC_TX | MCP251XFD_QUIRK_ECC,
40 	.model = MCP251XFD_MODEL_MCP2518FD,
41 };
42 
43 /* Autodetect model, start with CRC enabled. */
44 static const struct mcp251xfd_devtype_data mcp251xfd_devtype_data_mcp251xfd = {
45 	.quirks = MCP251XFD_QUIRK_CRC_REG | MCP251XFD_QUIRK_CRC_RX |
46 		MCP251XFD_QUIRK_CRC_TX | MCP251XFD_QUIRK_ECC,
47 	.model = MCP251XFD_MODEL_MCP251XFD,
48 };
49 
50 static const struct can_bittiming_const mcp251xfd_bittiming_const = {
51 	.name = DEVICE_NAME,
52 	.tseg1_min = 2,
53 	.tseg1_max = 256,
54 	.tseg2_min = 1,
55 	.tseg2_max = 128,
56 	.sjw_max = 128,
57 	.brp_min = 1,
58 	.brp_max = 256,
59 	.brp_inc = 1,
60 };
61 
62 static const struct can_bittiming_const mcp251xfd_data_bittiming_const = {
63 	.name = DEVICE_NAME,
64 	.tseg1_min = 1,
65 	.tseg1_max = 32,
66 	.tseg2_min = 1,
67 	.tseg2_max = 16,
68 	.sjw_max = 16,
69 	.brp_min = 1,
70 	.brp_max = 256,
71 	.brp_inc = 1,
72 };
73 
74 static const char *__mcp251xfd_get_model_str(enum mcp251xfd_model model)
75 {
76 	switch (model) {
77 	case MCP251XFD_MODEL_MCP2517FD:
78 		return "MCP2517FD"; break;
79 	case MCP251XFD_MODEL_MCP2518FD:
80 		return "MCP2518FD"; break;
81 	case MCP251XFD_MODEL_MCP251XFD:
82 		return "MCP251xFD"; break;
83 	}
84 
85 	return "<unknown>";
86 }
87 
88 static inline const char *
89 mcp251xfd_get_model_str(const struct mcp251xfd_priv *priv)
90 {
91 	return __mcp251xfd_get_model_str(priv->devtype_data.model);
92 }
93 
94 static const char *mcp251xfd_get_mode_str(const u8 mode)
95 {
96 	switch (mode) {
97 	case MCP251XFD_REG_CON_MODE_MIXED:
98 		return "Mixed (CAN FD/CAN 2.0)"; break;
99 	case MCP251XFD_REG_CON_MODE_SLEEP:
100 		return "Sleep"; break;
101 	case MCP251XFD_REG_CON_MODE_INT_LOOPBACK:
102 		return "Internal Loopback"; break;
103 	case MCP251XFD_REG_CON_MODE_LISTENONLY:
104 		return "Listen Only"; break;
105 	case MCP251XFD_REG_CON_MODE_CONFIG:
106 		return "Configuration"; break;
107 	case MCP251XFD_REG_CON_MODE_EXT_LOOPBACK:
108 		return "External Loopback"; break;
109 	case MCP251XFD_REG_CON_MODE_CAN2_0:
110 		return "CAN 2.0"; break;
111 	case MCP251XFD_REG_CON_MODE_RESTRICTED:
112 		return "Restricted Operation"; break;
113 	}
114 
115 	return "<unknown>";
116 }
117 
118 static inline int mcp251xfd_vdd_enable(const struct mcp251xfd_priv *priv)
119 {
120 	if (!priv->reg_vdd)
121 		return 0;
122 
123 	return regulator_enable(priv->reg_vdd);
124 }
125 
126 static inline int mcp251xfd_vdd_disable(const struct mcp251xfd_priv *priv)
127 {
128 	if (!priv->reg_vdd)
129 		return 0;
130 
131 	return regulator_disable(priv->reg_vdd);
132 }
133 
134 static inline int
135 mcp251xfd_transceiver_enable(const struct mcp251xfd_priv *priv)
136 {
137 	if (!priv->reg_xceiver)
138 		return 0;
139 
140 	return regulator_enable(priv->reg_xceiver);
141 }
142 
143 static inline int
144 mcp251xfd_transceiver_disable(const struct mcp251xfd_priv *priv)
145 {
146 	if (!priv->reg_xceiver)
147 		return 0;
148 
149 	return regulator_disable(priv->reg_xceiver);
150 }
151 
152 static int mcp251xfd_clks_and_vdd_enable(const struct mcp251xfd_priv *priv)
153 {
154 	int err;
155 
156 	err = clk_prepare_enable(priv->clk);
157 	if (err)
158 		return err;
159 
160 	err = mcp251xfd_vdd_enable(priv);
161 	if (err)
162 		clk_disable_unprepare(priv->clk);
163 
164 	/* Wait for oscillator stabilisation time after power up */
165 	usleep_range(MCP251XFD_OSC_STAB_SLEEP_US,
166 		     2 * MCP251XFD_OSC_STAB_SLEEP_US);
167 
168 	return err;
169 }
170 
171 static int mcp251xfd_clks_and_vdd_disable(const struct mcp251xfd_priv *priv)
172 {
173 	int err;
174 
175 	err = mcp251xfd_vdd_disable(priv);
176 	if (err)
177 		return err;
178 
179 	clk_disable_unprepare(priv->clk);
180 
181 	return 0;
182 }
183 
184 static inline u8
185 mcp251xfd_cmd_prepare_write_reg(const struct mcp251xfd_priv *priv,
186 				union mcp251xfd_write_reg_buf *write_reg_buf,
187 				const u16 reg, const u32 mask, const u32 val)
188 {
189 	u8 first_byte, last_byte, len;
190 	u8 *data;
191 	__le32 val_le32;
192 
193 	first_byte = mcp251xfd_first_byte_set(mask);
194 	last_byte = mcp251xfd_last_byte_set(mask);
195 	len = last_byte - first_byte + 1;
196 
197 	data = mcp251xfd_spi_cmd_write(priv, write_reg_buf, reg + first_byte);
198 	val_le32 = cpu_to_le32(val >> BITS_PER_BYTE * first_byte);
199 	memcpy(data, &val_le32, len);
200 
201 	if (priv->devtype_data.quirks & MCP251XFD_QUIRK_CRC_REG) {
202 		u16 crc;
203 
204 		mcp251xfd_spi_cmd_crc_set_len_in_reg(&write_reg_buf->crc.cmd,
205 						     len);
206 		/* CRC */
207 		len += sizeof(write_reg_buf->crc.cmd);
208 		crc = mcp251xfd_crc16_compute(&write_reg_buf->crc, len);
209 		put_unaligned_be16(crc, (void *)write_reg_buf + len);
210 
211 		/* Total length */
212 		len += sizeof(write_reg_buf->crc.crc);
213 	} else {
214 		len += sizeof(write_reg_buf->nocrc.cmd);
215 	}
216 
217 	return len;
218 }
219 
220 static inline int
221 mcp251xfd_tef_tail_get_from_chip(const struct mcp251xfd_priv *priv,
222 				 u8 *tef_tail)
223 {
224 	u32 tef_ua;
225 	int err;
226 
227 	err = regmap_read(priv->map_reg, MCP251XFD_REG_TEFUA, &tef_ua);
228 	if (err)
229 		return err;
230 
231 	*tef_tail = tef_ua / sizeof(struct mcp251xfd_hw_tef_obj);
232 
233 	return 0;
234 }
235 
236 static inline int
237 mcp251xfd_tx_tail_get_from_chip(const struct mcp251xfd_priv *priv,
238 				u8 *tx_tail)
239 {
240 	u32 fifo_sta;
241 	int err;
242 
243 	err = regmap_read(priv->map_reg,
244 			  MCP251XFD_REG_FIFOSTA(MCP251XFD_TX_FIFO),
245 			  &fifo_sta);
246 	if (err)
247 		return err;
248 
249 	*tx_tail = FIELD_GET(MCP251XFD_REG_FIFOSTA_FIFOCI_MASK, fifo_sta);
250 
251 	return 0;
252 }
253 
254 static inline int
255 mcp251xfd_rx_head_get_from_chip(const struct mcp251xfd_priv *priv,
256 				const struct mcp251xfd_rx_ring *ring,
257 				u8 *rx_head)
258 {
259 	u32 fifo_sta;
260 	int err;
261 
262 	err = regmap_read(priv->map_reg, MCP251XFD_REG_FIFOSTA(ring->fifo_nr),
263 			  &fifo_sta);
264 	if (err)
265 		return err;
266 
267 	*rx_head = FIELD_GET(MCP251XFD_REG_FIFOSTA_FIFOCI_MASK, fifo_sta);
268 
269 	return 0;
270 }
271 
272 static inline int
273 mcp251xfd_rx_tail_get_from_chip(const struct mcp251xfd_priv *priv,
274 				const struct mcp251xfd_rx_ring *ring,
275 				u8 *rx_tail)
276 {
277 	u32 fifo_ua;
278 	int err;
279 
280 	err = regmap_read(priv->map_reg, MCP251XFD_REG_FIFOUA(ring->fifo_nr),
281 			  &fifo_ua);
282 	if (err)
283 		return err;
284 
285 	fifo_ua -= ring->base - MCP251XFD_RAM_START;
286 	*rx_tail = fifo_ua / ring->obj_size;
287 
288 	return 0;
289 }
290 
291 static void
292 mcp251xfd_tx_ring_init_tx_obj(const struct mcp251xfd_priv *priv,
293 			      const struct mcp251xfd_tx_ring *ring,
294 			      struct mcp251xfd_tx_obj *tx_obj,
295 			      const u8 rts_buf_len,
296 			      const u8 n)
297 {
298 	struct spi_transfer *xfer;
299 	u16 addr;
300 
301 	/* FIFO load */
302 	addr = mcp251xfd_get_tx_obj_addr(ring, n);
303 	if (priv->devtype_data.quirks & MCP251XFD_QUIRK_CRC_TX)
304 		mcp251xfd_spi_cmd_write_crc_set_addr(&tx_obj->buf.crc.cmd,
305 						     addr);
306 	else
307 		mcp251xfd_spi_cmd_write_nocrc(&tx_obj->buf.nocrc.cmd,
308 					      addr);
309 
310 	xfer = &tx_obj->xfer[0];
311 	xfer->tx_buf = &tx_obj->buf;
312 	xfer->len = 0;	/* actual len is assigned on the fly */
313 	xfer->cs_change = 1;
314 	xfer->cs_change_delay.value = 0;
315 	xfer->cs_change_delay.unit = SPI_DELAY_UNIT_NSECS;
316 
317 	/* FIFO request to send */
318 	xfer = &tx_obj->xfer[1];
319 	xfer->tx_buf = &ring->rts_buf;
320 	xfer->len = rts_buf_len;
321 
322 	/* SPI message */
323 	spi_message_init_with_transfers(&tx_obj->msg, tx_obj->xfer,
324 					ARRAY_SIZE(tx_obj->xfer));
325 }
326 
327 static void mcp251xfd_ring_init(struct mcp251xfd_priv *priv)
328 {
329 	struct mcp251xfd_tx_ring *tx_ring;
330 	struct mcp251xfd_rx_ring *rx_ring, *prev_rx_ring = NULL;
331 	struct mcp251xfd_tx_obj *tx_obj;
332 	u32 val;
333 	u16 addr;
334 	u8 len;
335 	int i;
336 
337 	/* TEF */
338 	priv->tef.head = 0;
339 	priv->tef.tail = 0;
340 
341 	/* TX */
342 	tx_ring = priv->tx;
343 	tx_ring->head = 0;
344 	tx_ring->tail = 0;
345 	tx_ring->base = mcp251xfd_get_tef_obj_addr(tx_ring->obj_num);
346 
347 	/* FIFO request to send */
348 	addr = MCP251XFD_REG_FIFOCON(MCP251XFD_TX_FIFO);
349 	val = MCP251XFD_REG_FIFOCON_TXREQ | MCP251XFD_REG_FIFOCON_UINC;
350 	len = mcp251xfd_cmd_prepare_write_reg(priv, &tx_ring->rts_buf,
351 					      addr, val, val);
352 
353 	mcp251xfd_for_each_tx_obj(tx_ring, tx_obj, i)
354 		mcp251xfd_tx_ring_init_tx_obj(priv, tx_ring, tx_obj, len, i);
355 
356 	/* RX */
357 	mcp251xfd_for_each_rx_ring(priv, rx_ring, i) {
358 		rx_ring->head = 0;
359 		rx_ring->tail = 0;
360 		rx_ring->nr = i;
361 		rx_ring->fifo_nr = MCP251XFD_RX_FIFO(i);
362 
363 		if (!prev_rx_ring)
364 			rx_ring->base =
365 				mcp251xfd_get_tx_obj_addr(tx_ring,
366 							  tx_ring->obj_num);
367 		else
368 			rx_ring->base = prev_rx_ring->base +
369 				prev_rx_ring->obj_size *
370 				prev_rx_ring->obj_num;
371 
372 		prev_rx_ring = rx_ring;
373 	}
374 }
375 
376 static void mcp251xfd_ring_free(struct mcp251xfd_priv *priv)
377 {
378 	int i;
379 
380 	for (i = ARRAY_SIZE(priv->rx) - 1; i >= 0; i--) {
381 		kfree(priv->rx[i]);
382 		priv->rx[i] = NULL;
383 	}
384 }
385 
386 static int mcp251xfd_ring_alloc(struct mcp251xfd_priv *priv)
387 {
388 	struct mcp251xfd_tx_ring *tx_ring;
389 	struct mcp251xfd_rx_ring *rx_ring;
390 	int tef_obj_size, tx_obj_size, rx_obj_size;
391 	int tx_obj_num;
392 	int ram_free, i;
393 
394 	tef_obj_size = sizeof(struct mcp251xfd_hw_tef_obj);
395 	/* listen-only mode works like FD mode */
396 	if (priv->can.ctrlmode & (CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_FD)) {
397 		tx_obj_num = MCP251XFD_TX_OBJ_NUM_CANFD;
398 		tx_obj_size = sizeof(struct mcp251xfd_hw_tx_obj_canfd);
399 		rx_obj_size = sizeof(struct mcp251xfd_hw_rx_obj_canfd);
400 	} else {
401 		tx_obj_num = MCP251XFD_TX_OBJ_NUM_CAN;
402 		tx_obj_size = sizeof(struct mcp251xfd_hw_tx_obj_can);
403 		rx_obj_size = sizeof(struct mcp251xfd_hw_rx_obj_can);
404 	}
405 
406 	tx_ring = priv->tx;
407 	tx_ring->obj_num = tx_obj_num;
408 	tx_ring->obj_size = tx_obj_size;
409 
410 	ram_free = MCP251XFD_RAM_SIZE - tx_obj_num *
411 		(tef_obj_size + tx_obj_size);
412 
413 	for (i = 0;
414 	     i < ARRAY_SIZE(priv->rx) && ram_free >= rx_obj_size;
415 	     i++) {
416 		int rx_obj_num;
417 
418 		rx_obj_num = ram_free / rx_obj_size;
419 		rx_obj_num = min(1 << (fls(rx_obj_num) - 1), 32);
420 
421 		rx_ring = kzalloc(sizeof(*rx_ring) + rx_obj_size * rx_obj_num,
422 				  GFP_KERNEL);
423 		if (!rx_ring) {
424 			mcp251xfd_ring_free(priv);
425 			return -ENOMEM;
426 		}
427 		rx_ring->obj_num = rx_obj_num;
428 		rx_ring->obj_size = rx_obj_size;
429 		priv->rx[i] = rx_ring;
430 
431 		ram_free -= rx_ring->obj_num * rx_ring->obj_size;
432 	}
433 	priv->rx_ring_num = i;
434 
435 	netdev_dbg(priv->ndev,
436 		   "FIFO setup: TEF: %d*%d bytes = %d bytes, TX: %d*%d bytes = %d bytes\n",
437 		   tx_obj_num, tef_obj_size, tef_obj_size * tx_obj_num,
438 		   tx_obj_num, tx_obj_size, tx_obj_size * tx_obj_num);
439 
440 	mcp251xfd_for_each_rx_ring(priv, rx_ring, i) {
441 		netdev_dbg(priv->ndev,
442 			   "FIFO setup: RX-%d: %d*%d bytes = %d bytes\n",
443 			   i, rx_ring->obj_num, rx_ring->obj_size,
444 			   rx_ring->obj_size * rx_ring->obj_num);
445 	}
446 
447 	netdev_dbg(priv->ndev,
448 		   "FIFO setup: free: %d bytes\n",
449 		   ram_free);
450 
451 	return 0;
452 }
453 
454 static inline int
455 mcp251xfd_chip_get_mode(const struct mcp251xfd_priv *priv, u8 *mode)
456 {
457 	u32 val;
458 	int err;
459 
460 	err = regmap_read(priv->map_reg, MCP251XFD_REG_CON, &val);
461 	if (err)
462 		return err;
463 
464 	*mode = FIELD_GET(MCP251XFD_REG_CON_OPMOD_MASK, val);
465 
466 	return 0;
467 }
468 
469 static int
470 __mcp251xfd_chip_set_mode(const struct mcp251xfd_priv *priv,
471 			  const u8 mode_req, bool nowait)
472 {
473 	u32 con, con_reqop;
474 	int err;
475 
476 	con_reqop = FIELD_PREP(MCP251XFD_REG_CON_REQOP_MASK, mode_req);
477 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_CON,
478 				 MCP251XFD_REG_CON_REQOP_MASK, con_reqop);
479 	if (err)
480 		return err;
481 
482 	if (mode_req == MCP251XFD_REG_CON_MODE_SLEEP || nowait)
483 		return 0;
484 
485 	err = regmap_read_poll_timeout(priv->map_reg, MCP251XFD_REG_CON, con,
486 				       FIELD_GET(MCP251XFD_REG_CON_OPMOD_MASK,
487 						 con) == mode_req,
488 				       MCP251XFD_POLL_SLEEP_US,
489 				       MCP251XFD_POLL_TIMEOUT_US);
490 	if (err) {
491 		u8 mode = FIELD_GET(MCP251XFD_REG_CON_OPMOD_MASK, con);
492 
493 		netdev_err(priv->ndev,
494 			   "Controller failed to enter mode %s Mode (%u) and stays in %s Mode (%u).\n",
495 			   mcp251xfd_get_mode_str(mode_req), mode_req,
496 			   mcp251xfd_get_mode_str(mode), mode);
497 		return err;
498 	}
499 
500 	return 0;
501 }
502 
503 static inline int
504 mcp251xfd_chip_set_mode(const struct mcp251xfd_priv *priv,
505 			const u8 mode_req)
506 {
507 	return __mcp251xfd_chip_set_mode(priv, mode_req, false);
508 }
509 
510 static inline int
511 mcp251xfd_chip_set_mode_nowait(const struct mcp251xfd_priv *priv,
512 			       const u8 mode_req)
513 {
514 	return __mcp251xfd_chip_set_mode(priv, mode_req, true);
515 }
516 
517 static inline bool mcp251xfd_osc_invalid(u32 reg)
518 {
519 	return reg == 0x0 || reg == 0xffffffff;
520 }
521 
522 static int mcp251xfd_chip_clock_enable(const struct mcp251xfd_priv *priv)
523 {
524 	u32 osc, osc_reference, osc_mask;
525 	int err;
526 
527 	/* Set Power On Defaults for "Clock Output Divisor" and remove
528 	 * "Oscillator Disable" bit.
529 	 */
530 	osc = FIELD_PREP(MCP251XFD_REG_OSC_CLKODIV_MASK,
531 			 MCP251XFD_REG_OSC_CLKODIV_10);
532 	osc_reference = MCP251XFD_REG_OSC_OSCRDY;
533 	osc_mask = MCP251XFD_REG_OSC_OSCRDY | MCP251XFD_REG_OSC_PLLRDY;
534 
535 	/* Note:
536 	 *
537 	 * If the controller is in Sleep Mode the following write only
538 	 * removes the "Oscillator Disable" bit and powers it up. All
539 	 * other bits are unaffected.
540 	 */
541 	err = regmap_write(priv->map_reg, MCP251XFD_REG_OSC, osc);
542 	if (err)
543 		return err;
544 
545 	/* Wait for "Oscillator Ready" bit */
546 	err = regmap_read_poll_timeout(priv->map_reg, MCP251XFD_REG_OSC, osc,
547 				       (osc & osc_mask) == osc_reference,
548 				       MCP251XFD_OSC_STAB_SLEEP_US,
549 				       MCP251XFD_OSC_STAB_TIMEOUT_US);
550 	if (mcp251xfd_osc_invalid(osc)) {
551 		netdev_err(priv->ndev,
552 			   "Failed to detect %s (osc=0x%08x).\n",
553 			   mcp251xfd_get_model_str(priv), osc);
554 		return -ENODEV;
555 	} else if (err == -ETIMEDOUT) {
556 		netdev_err(priv->ndev,
557 			   "Timeout waiting for Oscillator Ready (osc=0x%08x, osc_reference=0x%08x)\n",
558 			   osc, osc_reference);
559 		return -ETIMEDOUT;
560 	} else if (err) {
561 		return err;
562 	}
563 
564 	return 0;
565 }
566 
567 static int mcp251xfd_chip_softreset_do(const struct mcp251xfd_priv *priv)
568 {
569 	const __be16 cmd = mcp251xfd_cmd_reset();
570 	int err;
571 
572 	/* The Set Mode and SPI Reset command only seems to works if
573 	 * the controller is not in Sleep Mode.
574 	 */
575 	err = mcp251xfd_chip_clock_enable(priv);
576 	if (err)
577 		return err;
578 
579 	err = mcp251xfd_chip_set_mode(priv, MCP251XFD_REG_CON_MODE_CONFIG);
580 	if (err)
581 		return err;
582 
583 	/* spi_write_then_read() works with non DMA-safe buffers */
584 	return spi_write_then_read(priv->spi, &cmd, sizeof(cmd), NULL, 0);
585 }
586 
587 static int mcp251xfd_chip_softreset_check(const struct mcp251xfd_priv *priv)
588 {
589 	u32 osc, osc_reference;
590 	u8 mode;
591 	int err;
592 
593 	err = mcp251xfd_chip_get_mode(priv, &mode);
594 	if (err)
595 		return err;
596 
597 	if (mode != MCP251XFD_REG_CON_MODE_CONFIG) {
598 		netdev_info(priv->ndev,
599 			    "Controller not in Config Mode after reset, but in %s Mode (%u).\n",
600 			    mcp251xfd_get_mode_str(mode), mode);
601 		return -ETIMEDOUT;
602 	}
603 
604 	osc_reference = MCP251XFD_REG_OSC_OSCRDY |
605 		FIELD_PREP(MCP251XFD_REG_OSC_CLKODIV_MASK,
606 			   MCP251XFD_REG_OSC_CLKODIV_10);
607 
608 	/* check reset defaults of OSC reg */
609 	err = regmap_read(priv->map_reg, MCP251XFD_REG_OSC, &osc);
610 	if (err)
611 		return err;
612 
613 	if (osc != osc_reference) {
614 		netdev_info(priv->ndev,
615 			    "Controller failed to reset. osc=0x%08x, reference value=0x%08x\n",
616 			    osc, osc_reference);
617 		return -ETIMEDOUT;
618 	}
619 
620 	return 0;
621 }
622 
623 static int mcp251xfd_chip_softreset(const struct mcp251xfd_priv *priv)
624 {
625 	int err, i;
626 
627 	for (i = 0; i < MCP251XFD_SOFTRESET_RETRIES_MAX; i++) {
628 		if (i)
629 			netdev_info(priv->ndev,
630 				    "Retrying to reset Controller.\n");
631 
632 		err = mcp251xfd_chip_softreset_do(priv);
633 		if (err == -ETIMEDOUT)
634 			continue;
635 		if (err)
636 			return err;
637 
638 		err = mcp251xfd_chip_softreset_check(priv);
639 		if (err == -ETIMEDOUT)
640 			continue;
641 		if (err)
642 			return err;
643 
644 		return 0;
645 	}
646 
647 	if (err)
648 		return err;
649 
650 	return -ETIMEDOUT;
651 }
652 
653 static int mcp251xfd_chip_clock_init(const struct mcp251xfd_priv *priv)
654 {
655 	u32 osc;
656 	int err;
657 
658 	/* Activate Low Power Mode on Oscillator Disable. This only
659 	 * works on the MCP2518FD. The MCP2517FD will go into normal
660 	 * Sleep Mode instead.
661 	 */
662 	osc = MCP251XFD_REG_OSC_LPMEN |
663 		FIELD_PREP(MCP251XFD_REG_OSC_CLKODIV_MASK,
664 			   MCP251XFD_REG_OSC_CLKODIV_10);
665 	err = regmap_write(priv->map_reg, MCP251XFD_REG_OSC, osc);
666 	if (err)
667 		return err;
668 
669 	/* Set Time Base Counter Prescaler to 1.
670 	 *
671 	 * This means an overflow of the 32 bit Time Base Counter
672 	 * register at 40 MHz every 107 seconds.
673 	 */
674 	return regmap_write(priv->map_reg, MCP251XFD_REG_TSCON,
675 			    MCP251XFD_REG_TSCON_TBCEN);
676 }
677 
678 static int mcp251xfd_set_bittiming(const struct mcp251xfd_priv *priv)
679 {
680 	const struct can_bittiming *bt = &priv->can.bittiming;
681 	const struct can_bittiming *dbt = &priv->can.data_bittiming;
682 	u32 val = 0;
683 	s8 tdco;
684 	int err;
685 
686 	/* CAN Control Register
687 	 *
688 	 * - no transmit bandwidth sharing
689 	 * - config mode
690 	 * - disable transmit queue
691 	 * - store in transmit FIFO event
692 	 * - transition to restricted operation mode on system error
693 	 * - ESI is transmitted recessive when ESI of message is high or
694 	 *   CAN controller error passive
695 	 * - restricted retransmission attempts,
696 	 *   use TQXCON_TXAT and FIFOCON_TXAT
697 	 * - wake-up filter bits T11FILTER
698 	 * - use CAN bus line filter for wakeup
699 	 * - protocol exception is treated as a form error
700 	 * - Do not compare data bytes
701 	 */
702 	val = FIELD_PREP(MCP251XFD_REG_CON_REQOP_MASK,
703 			 MCP251XFD_REG_CON_MODE_CONFIG) |
704 		MCP251XFD_REG_CON_STEF |
705 		MCP251XFD_REG_CON_ESIGM |
706 		MCP251XFD_REG_CON_RTXAT |
707 		FIELD_PREP(MCP251XFD_REG_CON_WFT_MASK,
708 			   MCP251XFD_REG_CON_WFT_T11FILTER) |
709 		MCP251XFD_REG_CON_WAKFIL |
710 		MCP251XFD_REG_CON_PXEDIS;
711 
712 	if (!(priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO))
713 		val |= MCP251XFD_REG_CON_ISOCRCEN;
714 
715 	err = regmap_write(priv->map_reg, MCP251XFD_REG_CON, val);
716 	if (err)
717 		return err;
718 
719 	/* Nominal Bit Time */
720 	val = FIELD_PREP(MCP251XFD_REG_NBTCFG_BRP_MASK, bt->brp - 1) |
721 		FIELD_PREP(MCP251XFD_REG_NBTCFG_TSEG1_MASK,
722 			   bt->prop_seg + bt->phase_seg1 - 1) |
723 		FIELD_PREP(MCP251XFD_REG_NBTCFG_TSEG2_MASK,
724 			   bt->phase_seg2 - 1) |
725 		FIELD_PREP(MCP251XFD_REG_NBTCFG_SJW_MASK, bt->sjw - 1);
726 
727 	err = regmap_write(priv->map_reg, MCP251XFD_REG_NBTCFG, val);
728 	if (err)
729 		return err;
730 
731 	if (!(priv->can.ctrlmode & CAN_CTRLMODE_FD))
732 		return 0;
733 
734 	/* Data Bit Time */
735 	val = FIELD_PREP(MCP251XFD_REG_DBTCFG_BRP_MASK, dbt->brp - 1) |
736 		FIELD_PREP(MCP251XFD_REG_DBTCFG_TSEG1_MASK,
737 			   dbt->prop_seg + dbt->phase_seg1 - 1) |
738 		FIELD_PREP(MCP251XFD_REG_DBTCFG_TSEG2_MASK,
739 			   dbt->phase_seg2 - 1) |
740 		FIELD_PREP(MCP251XFD_REG_DBTCFG_SJW_MASK, dbt->sjw - 1);
741 
742 	err = regmap_write(priv->map_reg, MCP251XFD_REG_DBTCFG, val);
743 	if (err)
744 		return err;
745 
746 	/* Transmitter Delay Compensation */
747 	tdco = clamp_t(int, dbt->brp * (dbt->prop_seg + dbt->phase_seg1),
748 		       -64, 63);
749 	val = FIELD_PREP(MCP251XFD_REG_TDC_TDCMOD_MASK,
750 			 MCP251XFD_REG_TDC_TDCMOD_AUTO) |
751 		FIELD_PREP(MCP251XFD_REG_TDC_TDCO_MASK, tdco);
752 
753 	return regmap_write(priv->map_reg, MCP251XFD_REG_TDC, val);
754 }
755 
756 static int mcp251xfd_chip_rx_int_enable(const struct mcp251xfd_priv *priv)
757 {
758 	u32 val;
759 
760 	if (!priv->rx_int)
761 		return 0;
762 
763 	/* Configure GPIOs:
764 	 * - PIN0: GPIO Input
765 	 * - PIN1: GPIO Input/RX Interrupt
766 	 *
767 	 * PIN1 must be Input, otherwise there is a glitch on the
768 	 * rx-INT line. It happens between setting the PIN as output
769 	 * (in the first byte of the SPI transfer) and configuring the
770 	 * PIN as interrupt (in the last byte of the SPI transfer).
771 	 */
772 	val = MCP251XFD_REG_IOCON_PM0 | MCP251XFD_REG_IOCON_TRIS1 |
773 		MCP251XFD_REG_IOCON_TRIS0;
774 	return regmap_write(priv->map_reg, MCP251XFD_REG_IOCON, val);
775 }
776 
777 static int mcp251xfd_chip_rx_int_disable(const struct mcp251xfd_priv *priv)
778 {
779 	u32 val;
780 
781 	if (!priv->rx_int)
782 		return 0;
783 
784 	/* Configure GPIOs:
785 	 * - PIN0: GPIO Input
786 	 * - PIN1: GPIO Input
787 	 */
788 	val = MCP251XFD_REG_IOCON_PM1 | MCP251XFD_REG_IOCON_PM0 |
789 		MCP251XFD_REG_IOCON_TRIS1 | MCP251XFD_REG_IOCON_TRIS0;
790 	return regmap_write(priv->map_reg, MCP251XFD_REG_IOCON, val);
791 }
792 
793 static int
794 mcp251xfd_chip_rx_fifo_init_one(const struct mcp251xfd_priv *priv,
795 				const struct mcp251xfd_rx_ring *ring)
796 {
797 	u32 fifo_con;
798 
799 	/* Enable RXOVIE on _all_ RX FIFOs, not just the last one.
800 	 *
801 	 * FIFOs hit by a RX MAB overflow and RXOVIE enabled will
802 	 * generate a RXOVIF, use this to properly detect RX MAB
803 	 * overflows.
804 	 */
805 	fifo_con = FIELD_PREP(MCP251XFD_REG_FIFOCON_FSIZE_MASK,
806 			      ring->obj_num - 1) |
807 		MCP251XFD_REG_FIFOCON_RXTSEN |
808 		MCP251XFD_REG_FIFOCON_RXOVIE |
809 		MCP251XFD_REG_FIFOCON_TFNRFNIE;
810 
811 	if (priv->can.ctrlmode & (CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_FD))
812 		fifo_con |= FIELD_PREP(MCP251XFD_REG_FIFOCON_PLSIZE_MASK,
813 				       MCP251XFD_REG_FIFOCON_PLSIZE_64);
814 	else
815 		fifo_con |= FIELD_PREP(MCP251XFD_REG_FIFOCON_PLSIZE_MASK,
816 				       MCP251XFD_REG_FIFOCON_PLSIZE_8);
817 
818 	return regmap_write(priv->map_reg,
819 			    MCP251XFD_REG_FIFOCON(ring->fifo_nr), fifo_con);
820 }
821 
822 static int
823 mcp251xfd_chip_rx_filter_init_one(const struct mcp251xfd_priv *priv,
824 				  const struct mcp251xfd_rx_ring *ring)
825 {
826 	u32 fltcon;
827 
828 	fltcon = MCP251XFD_REG_FLTCON_FLTEN(ring->nr) |
829 		MCP251XFD_REG_FLTCON_FBP(ring->nr, ring->fifo_nr);
830 
831 	return regmap_update_bits(priv->map_reg,
832 				  MCP251XFD_REG_FLTCON(ring->nr >> 2),
833 				  MCP251XFD_REG_FLTCON_FLT_MASK(ring->nr),
834 				  fltcon);
835 }
836 
837 static int mcp251xfd_chip_fifo_init(const struct mcp251xfd_priv *priv)
838 {
839 	const struct mcp251xfd_tx_ring *tx_ring = priv->tx;
840 	const struct mcp251xfd_rx_ring *rx_ring;
841 	u32 val;
842 	int err, n;
843 
844 	/* TEF */
845 	val = FIELD_PREP(MCP251XFD_REG_TEFCON_FSIZE_MASK,
846 			 tx_ring->obj_num - 1) |
847 		MCP251XFD_REG_TEFCON_TEFTSEN |
848 		MCP251XFD_REG_TEFCON_TEFOVIE |
849 		MCP251XFD_REG_TEFCON_TEFNEIE;
850 
851 	err = regmap_write(priv->map_reg, MCP251XFD_REG_TEFCON, val);
852 	if (err)
853 		return err;
854 
855 	/* FIFO 1 - TX */
856 	val = FIELD_PREP(MCP251XFD_REG_FIFOCON_FSIZE_MASK,
857 			 tx_ring->obj_num - 1) |
858 		MCP251XFD_REG_FIFOCON_TXEN |
859 		MCP251XFD_REG_FIFOCON_TXATIE;
860 
861 	if (priv->can.ctrlmode & (CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_FD))
862 		val |= FIELD_PREP(MCP251XFD_REG_FIFOCON_PLSIZE_MASK,
863 				  MCP251XFD_REG_FIFOCON_PLSIZE_64);
864 	else
865 		val |= FIELD_PREP(MCP251XFD_REG_FIFOCON_PLSIZE_MASK,
866 				  MCP251XFD_REG_FIFOCON_PLSIZE_8);
867 
868 	if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
869 		val |= FIELD_PREP(MCP251XFD_REG_FIFOCON_TXAT_MASK,
870 				  MCP251XFD_REG_FIFOCON_TXAT_ONE_SHOT);
871 	else
872 		val |= FIELD_PREP(MCP251XFD_REG_FIFOCON_TXAT_MASK,
873 				  MCP251XFD_REG_FIFOCON_TXAT_UNLIMITED);
874 
875 	err = regmap_write(priv->map_reg,
876 			   MCP251XFD_REG_FIFOCON(MCP251XFD_TX_FIFO),
877 			   val);
878 	if (err)
879 		return err;
880 
881 	/* RX FIFOs */
882 	mcp251xfd_for_each_rx_ring(priv, rx_ring, n) {
883 		err = mcp251xfd_chip_rx_fifo_init_one(priv, rx_ring);
884 		if (err)
885 			return err;
886 
887 		err = mcp251xfd_chip_rx_filter_init_one(priv, rx_ring);
888 		if (err)
889 			return err;
890 	}
891 
892 	return 0;
893 }
894 
895 static int mcp251xfd_chip_ecc_init(struct mcp251xfd_priv *priv)
896 {
897 	struct mcp251xfd_ecc *ecc = &priv->ecc;
898 	void *ram;
899 	u32 val = 0;
900 	int err;
901 
902 	ecc->ecc_stat = 0;
903 
904 	if (priv->devtype_data.quirks & MCP251XFD_QUIRK_ECC)
905 		val = MCP251XFD_REG_ECCCON_ECCEN;
906 
907 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_ECCCON,
908 				 MCP251XFD_REG_ECCCON_ECCEN, val);
909 	if (err)
910 		return err;
911 
912 	ram = kzalloc(MCP251XFD_RAM_SIZE, GFP_KERNEL);
913 	if (!ram)
914 		return -ENOMEM;
915 
916 	err = regmap_raw_write(priv->map_reg, MCP251XFD_RAM_START, ram,
917 			       MCP251XFD_RAM_SIZE);
918 	kfree(ram);
919 
920 	return err;
921 }
922 
923 static inline void mcp251xfd_ecc_tefif_successful(struct mcp251xfd_priv *priv)
924 {
925 	struct mcp251xfd_ecc *ecc = &priv->ecc;
926 
927 	ecc->ecc_stat = 0;
928 }
929 
930 static u8 mcp251xfd_get_normal_mode(const struct mcp251xfd_priv *priv)
931 {
932 	u8 mode;
933 
934 	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
935 		mode = MCP251XFD_REG_CON_MODE_LISTENONLY;
936 	else if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
937 		mode = MCP251XFD_REG_CON_MODE_MIXED;
938 	else
939 		mode = MCP251XFD_REG_CON_MODE_CAN2_0;
940 
941 	return mode;
942 }
943 
944 static int
945 __mcp251xfd_chip_set_normal_mode(const struct mcp251xfd_priv *priv,
946 				 bool nowait)
947 {
948 	u8 mode;
949 
950 	mode = mcp251xfd_get_normal_mode(priv);
951 
952 	return __mcp251xfd_chip_set_mode(priv, mode, nowait);
953 }
954 
955 static inline int
956 mcp251xfd_chip_set_normal_mode(const struct mcp251xfd_priv *priv)
957 {
958 	return __mcp251xfd_chip_set_normal_mode(priv, false);
959 }
960 
961 static inline int
962 mcp251xfd_chip_set_normal_mode_nowait(const struct mcp251xfd_priv *priv)
963 {
964 	return __mcp251xfd_chip_set_normal_mode(priv, true);
965 }
966 
967 static int mcp251xfd_chip_interrupts_enable(const struct mcp251xfd_priv *priv)
968 {
969 	u32 val;
970 	int err;
971 
972 	val = MCP251XFD_REG_CRC_FERRIE | MCP251XFD_REG_CRC_CRCERRIE;
973 	err = regmap_write(priv->map_reg, MCP251XFD_REG_CRC, val);
974 	if (err)
975 		return err;
976 
977 	val = MCP251XFD_REG_ECCCON_DEDIE | MCP251XFD_REG_ECCCON_SECIE;
978 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_ECCCON, val, val);
979 	if (err)
980 		return err;
981 
982 	val = MCP251XFD_REG_INT_CERRIE |
983 		MCP251XFD_REG_INT_SERRIE |
984 		MCP251XFD_REG_INT_RXOVIE |
985 		MCP251XFD_REG_INT_TXATIE |
986 		MCP251XFD_REG_INT_SPICRCIE |
987 		MCP251XFD_REG_INT_ECCIE |
988 		MCP251XFD_REG_INT_TEFIE |
989 		MCP251XFD_REG_INT_MODIE |
990 		MCP251XFD_REG_INT_RXIE;
991 
992 	if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
993 		val |= MCP251XFD_REG_INT_IVMIE;
994 
995 	return regmap_write(priv->map_reg, MCP251XFD_REG_INT, val);
996 }
997 
998 static int mcp251xfd_chip_interrupts_disable(const struct mcp251xfd_priv *priv)
999 {
1000 	int err;
1001 	u32 mask;
1002 
1003 	err = regmap_write(priv->map_reg, MCP251XFD_REG_INT, 0);
1004 	if (err)
1005 		return err;
1006 
1007 	mask = MCP251XFD_REG_ECCCON_DEDIE | MCP251XFD_REG_ECCCON_SECIE;
1008 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_ECCCON,
1009 				 mask, 0x0);
1010 	if (err)
1011 		return err;
1012 
1013 	return regmap_write(priv->map_reg, MCP251XFD_REG_CRC, 0);
1014 }
1015 
1016 static int mcp251xfd_chip_stop(struct mcp251xfd_priv *priv,
1017 			       const enum can_state state)
1018 {
1019 	priv->can.state = state;
1020 
1021 	mcp251xfd_chip_interrupts_disable(priv);
1022 	mcp251xfd_chip_rx_int_disable(priv);
1023 	return mcp251xfd_chip_set_mode(priv, MCP251XFD_REG_CON_MODE_SLEEP);
1024 }
1025 
1026 static int mcp251xfd_chip_start(struct mcp251xfd_priv *priv)
1027 {
1028 	int err;
1029 
1030 	err = mcp251xfd_chip_softreset(priv);
1031 	if (err)
1032 		goto out_chip_stop;
1033 
1034 	err = mcp251xfd_chip_clock_init(priv);
1035 	if (err)
1036 		goto out_chip_stop;
1037 
1038 	err = mcp251xfd_set_bittiming(priv);
1039 	if (err)
1040 		goto out_chip_stop;
1041 
1042 	err = mcp251xfd_chip_rx_int_enable(priv);
1043 	if (err)
1044 		return err;
1045 
1046 	err = mcp251xfd_chip_ecc_init(priv);
1047 	if (err)
1048 		goto out_chip_stop;
1049 
1050 	mcp251xfd_ring_init(priv);
1051 
1052 	err = mcp251xfd_chip_fifo_init(priv);
1053 	if (err)
1054 		goto out_chip_stop;
1055 
1056 	priv->can.state = CAN_STATE_ERROR_ACTIVE;
1057 
1058 	err = mcp251xfd_chip_set_normal_mode(priv);
1059 	if (err)
1060 		goto out_chip_stop;
1061 
1062 	return 0;
1063 
1064  out_chip_stop:
1065 	mcp251xfd_chip_stop(priv, CAN_STATE_STOPPED);
1066 
1067 	return err;
1068 }
1069 
1070 static int mcp251xfd_set_mode(struct net_device *ndev, enum can_mode mode)
1071 {
1072 	struct mcp251xfd_priv *priv = netdev_priv(ndev);
1073 	int err;
1074 
1075 	switch (mode) {
1076 	case CAN_MODE_START:
1077 		err = mcp251xfd_chip_start(priv);
1078 		if (err)
1079 			return err;
1080 
1081 		err = mcp251xfd_chip_interrupts_enable(priv);
1082 		if (err) {
1083 			mcp251xfd_chip_stop(priv, CAN_STATE_STOPPED);
1084 			return err;
1085 		}
1086 
1087 		netif_wake_queue(ndev);
1088 		break;
1089 
1090 	default:
1091 		return -EOPNOTSUPP;
1092 	}
1093 
1094 	return 0;
1095 }
1096 
1097 static int __mcp251xfd_get_berr_counter(const struct net_device *ndev,
1098 					struct can_berr_counter *bec)
1099 {
1100 	const struct mcp251xfd_priv *priv = netdev_priv(ndev);
1101 	u32 trec;
1102 	int err;
1103 
1104 	err = regmap_read(priv->map_reg, MCP251XFD_REG_TREC, &trec);
1105 	if (err)
1106 		return err;
1107 
1108 	if (trec & MCP251XFD_REG_TREC_TXBO)
1109 		bec->txerr = 256;
1110 	else
1111 		bec->txerr = FIELD_GET(MCP251XFD_REG_TREC_TEC_MASK, trec);
1112 	bec->rxerr = FIELD_GET(MCP251XFD_REG_TREC_REC_MASK, trec);
1113 
1114 	return 0;
1115 }
1116 
1117 static int mcp251xfd_get_berr_counter(const struct net_device *ndev,
1118 				      struct can_berr_counter *bec)
1119 {
1120 	const struct mcp251xfd_priv *priv = netdev_priv(ndev);
1121 
1122 	/* Avoid waking up the controller if the interface is down */
1123 	if (!(ndev->flags & IFF_UP))
1124 		return 0;
1125 
1126 	/* The controller is powered down during Bus Off, use saved
1127 	 * bec values.
1128 	 */
1129 	if (priv->can.state == CAN_STATE_BUS_OFF) {
1130 		*bec = priv->bec;
1131 		return 0;
1132 	}
1133 
1134 	return __mcp251xfd_get_berr_counter(ndev, bec);
1135 }
1136 
1137 static int mcp251xfd_check_tef_tail(const struct mcp251xfd_priv *priv)
1138 {
1139 	u8 tef_tail_chip, tef_tail;
1140 	int err;
1141 
1142 	if (!IS_ENABLED(CONFIG_CAN_MCP251XFD_SANITY))
1143 		return 0;
1144 
1145 	err = mcp251xfd_tef_tail_get_from_chip(priv, &tef_tail_chip);
1146 	if (err)
1147 		return err;
1148 
1149 	tef_tail = mcp251xfd_get_tef_tail(priv);
1150 	if (tef_tail_chip != tef_tail) {
1151 		netdev_err(priv->ndev,
1152 			   "TEF tail of chip (0x%02x) and ours (0x%08x) inconsistent.\n",
1153 			   tef_tail_chip, tef_tail);
1154 		return -EILSEQ;
1155 	}
1156 
1157 	return 0;
1158 }
1159 
1160 static int
1161 mcp251xfd_check_rx_tail(const struct mcp251xfd_priv *priv,
1162 			const struct mcp251xfd_rx_ring *ring)
1163 {
1164 	u8 rx_tail_chip, rx_tail;
1165 	int err;
1166 
1167 	if (!IS_ENABLED(CONFIG_CAN_MCP251XFD_SANITY))
1168 		return 0;
1169 
1170 	err = mcp251xfd_rx_tail_get_from_chip(priv, ring, &rx_tail_chip);
1171 	if (err)
1172 		return err;
1173 
1174 	rx_tail = mcp251xfd_get_rx_tail(ring);
1175 	if (rx_tail_chip != rx_tail) {
1176 		netdev_err(priv->ndev,
1177 			   "RX tail of chip (%d) and ours (%d) inconsistent.\n",
1178 			   rx_tail_chip, rx_tail);
1179 		return -EILSEQ;
1180 	}
1181 
1182 	return 0;
1183 }
1184 
1185 static int
1186 mcp251xfd_handle_tefif_recover(const struct mcp251xfd_priv *priv, const u32 seq)
1187 {
1188 	const struct mcp251xfd_tx_ring *tx_ring = priv->tx;
1189 	u32 tef_sta;
1190 	int err;
1191 
1192 	err = regmap_read(priv->map_reg, MCP251XFD_REG_TEFSTA, &tef_sta);
1193 	if (err)
1194 		return err;
1195 
1196 	if (tef_sta & MCP251XFD_REG_TEFSTA_TEFOVIF) {
1197 		netdev_err(priv->ndev,
1198 			   "Transmit Event FIFO buffer overflow.\n");
1199 		return -ENOBUFS;
1200 	}
1201 
1202 	netdev_info(priv->ndev,
1203 		    "Transmit Event FIFO buffer %s. (seq=0x%08x, tef_tail=0x%08x, tef_head=0x%08x, tx_head=0x%08x)\n",
1204 		    tef_sta & MCP251XFD_REG_TEFSTA_TEFFIF ?
1205 		    "full" : tef_sta & MCP251XFD_REG_TEFSTA_TEFNEIF ?
1206 		    "not empty" : "empty",
1207 		    seq, priv->tef.tail, priv->tef.head, tx_ring->head);
1208 
1209 	/* The Sequence Number in the TEF doesn't match our tef_tail. */
1210 	return -EAGAIN;
1211 }
1212 
1213 static int
1214 mcp251xfd_handle_tefif_one(struct mcp251xfd_priv *priv,
1215 			   const struct mcp251xfd_hw_tef_obj *hw_tef_obj)
1216 {
1217 	struct mcp251xfd_tx_ring *tx_ring = priv->tx;
1218 	struct net_device_stats *stats = &priv->ndev->stats;
1219 	u32 seq, seq_masked, tef_tail_masked;
1220 	int err;
1221 
1222 	seq = FIELD_GET(MCP251XFD_OBJ_FLAGS_SEQ_MCP2518FD_MASK,
1223 			hw_tef_obj->flags);
1224 
1225 	/* Use the MCP2517FD mask on the MCP2518FD, too. We only
1226 	 * compare 7 bits, this should be enough to detect
1227 	 * net-yet-completed, i.e. old TEF objects.
1228 	 */
1229 	seq_masked = seq &
1230 		field_mask(MCP251XFD_OBJ_FLAGS_SEQ_MCP2517FD_MASK);
1231 	tef_tail_masked = priv->tef.tail &
1232 		field_mask(MCP251XFD_OBJ_FLAGS_SEQ_MCP2517FD_MASK);
1233 	if (seq_masked != tef_tail_masked)
1234 		return mcp251xfd_handle_tefif_recover(priv, seq);
1235 
1236 	stats->tx_bytes +=
1237 		can_rx_offload_get_echo_skb(&priv->offload,
1238 					    mcp251xfd_get_tef_tail(priv),
1239 					    hw_tef_obj->ts);
1240 	stats->tx_packets++;
1241 
1242 	/* finally increment the TEF pointer */
1243 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_TEFCON,
1244 				 GENMASK(15, 8),
1245 				 MCP251XFD_REG_TEFCON_UINC);
1246 	if (err)
1247 		return err;
1248 
1249 	priv->tef.tail++;
1250 	tx_ring->tail++;
1251 
1252 	return mcp251xfd_check_tef_tail(priv);
1253 }
1254 
1255 static int mcp251xfd_tef_ring_update(struct mcp251xfd_priv *priv)
1256 {
1257 	const struct mcp251xfd_tx_ring *tx_ring = priv->tx;
1258 	unsigned int new_head;
1259 	u8 chip_tx_tail;
1260 	int err;
1261 
1262 	err = mcp251xfd_tx_tail_get_from_chip(priv, &chip_tx_tail);
1263 	if (err)
1264 		return err;
1265 
1266 	/* chip_tx_tail, is the next TX-Object send by the HW.
1267 	 * The new TEF head must be >= the old head, ...
1268 	 */
1269 	new_head = round_down(priv->tef.head, tx_ring->obj_num) + chip_tx_tail;
1270 	if (new_head <= priv->tef.head)
1271 		new_head += tx_ring->obj_num;
1272 
1273 	/* ... but it cannot exceed the TX head. */
1274 	priv->tef.head = min(new_head, tx_ring->head);
1275 
1276 	return mcp251xfd_check_tef_tail(priv);
1277 }
1278 
1279 static inline int
1280 mcp251xfd_tef_obj_read(const struct mcp251xfd_priv *priv,
1281 		       struct mcp251xfd_hw_tef_obj *hw_tef_obj,
1282 		       const u8 offset, const u8 len)
1283 {
1284 	const struct mcp251xfd_tx_ring *tx_ring = priv->tx;
1285 
1286 	if (IS_ENABLED(CONFIG_CAN_MCP251XFD_SANITY) &&
1287 	    (offset > tx_ring->obj_num ||
1288 	     len > tx_ring->obj_num ||
1289 	     offset + len > tx_ring->obj_num)) {
1290 		netdev_err(priv->ndev,
1291 			   "Trying to read to many TEF objects (max=%d, offset=%d, len=%d).\n",
1292 			   tx_ring->obj_num, offset, len);
1293 		return -ERANGE;
1294 	}
1295 
1296 	return regmap_bulk_read(priv->map_rx,
1297 				mcp251xfd_get_tef_obj_addr(offset),
1298 				hw_tef_obj,
1299 				sizeof(*hw_tef_obj) / sizeof(u32) * len);
1300 }
1301 
1302 static int mcp251xfd_handle_tefif(struct mcp251xfd_priv *priv)
1303 {
1304 	struct mcp251xfd_hw_tef_obj hw_tef_obj[MCP251XFD_TX_OBJ_NUM_MAX];
1305 	u8 tef_tail, len, l;
1306 	int err, i;
1307 
1308 	err = mcp251xfd_tef_ring_update(priv);
1309 	if (err)
1310 		return err;
1311 
1312 	tef_tail = mcp251xfd_get_tef_tail(priv);
1313 	len = mcp251xfd_get_tef_len(priv);
1314 	l = mcp251xfd_get_tef_linear_len(priv);
1315 	err = mcp251xfd_tef_obj_read(priv, hw_tef_obj, tef_tail, l);
1316 	if (err)
1317 		return err;
1318 
1319 	if (l < len) {
1320 		err = mcp251xfd_tef_obj_read(priv, &hw_tef_obj[l], 0, len - l);
1321 		if (err)
1322 			return err;
1323 	}
1324 
1325 	for (i = 0; i < len; i++) {
1326 		err = mcp251xfd_handle_tefif_one(priv, &hw_tef_obj[i]);
1327 		/* -EAGAIN means the Sequence Number in the TEF
1328 		 * doesn't match our tef_tail. This can happen if we
1329 		 * read the TEF objects too early. Leave loop let the
1330 		 * interrupt handler call us again.
1331 		 */
1332 		if (err == -EAGAIN)
1333 			goto out_netif_wake_queue;
1334 		if (err)
1335 			return err;
1336 	}
1337 
1338  out_netif_wake_queue:
1339 	mcp251xfd_ecc_tefif_successful(priv);
1340 
1341 	if (mcp251xfd_get_tx_free(priv->tx)) {
1342 		/* Make sure that anybody stopping the queue after
1343 		 * this sees the new tx_ring->tail.
1344 		 */
1345 		smp_mb();
1346 		netif_wake_queue(priv->ndev);
1347 	}
1348 
1349 	return 0;
1350 }
1351 
1352 static int
1353 mcp251xfd_rx_ring_update(const struct mcp251xfd_priv *priv,
1354 			 struct mcp251xfd_rx_ring *ring)
1355 {
1356 	u32 new_head;
1357 	u8 chip_rx_head;
1358 	int err;
1359 
1360 	err = mcp251xfd_rx_head_get_from_chip(priv, ring, &chip_rx_head);
1361 	if (err)
1362 		return err;
1363 
1364 	/* chip_rx_head, is the next RX-Object filled by the HW.
1365 	 * The new RX head must be >= the old head.
1366 	 */
1367 	new_head = round_down(ring->head, ring->obj_num) + chip_rx_head;
1368 	if (new_head <= ring->head)
1369 		new_head += ring->obj_num;
1370 
1371 	ring->head = new_head;
1372 
1373 	return mcp251xfd_check_rx_tail(priv, ring);
1374 }
1375 
1376 static void
1377 mcp251xfd_hw_rx_obj_to_skb(const struct mcp251xfd_priv *priv,
1378 			   const struct mcp251xfd_hw_rx_obj_canfd *hw_rx_obj,
1379 			   struct sk_buff *skb)
1380 {
1381 	struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
1382 
1383 	if (hw_rx_obj->flags & MCP251XFD_OBJ_FLAGS_IDE) {
1384 		u32 sid, eid;
1385 
1386 		eid = FIELD_GET(MCP251XFD_OBJ_ID_EID_MASK, hw_rx_obj->id);
1387 		sid = FIELD_GET(MCP251XFD_OBJ_ID_SID_MASK, hw_rx_obj->id);
1388 
1389 		cfd->can_id = CAN_EFF_FLAG |
1390 			FIELD_PREP(MCP251XFD_REG_FRAME_EFF_EID_MASK, eid) |
1391 			FIELD_PREP(MCP251XFD_REG_FRAME_EFF_SID_MASK, sid);
1392 	} else {
1393 		cfd->can_id = FIELD_GET(MCP251XFD_OBJ_ID_SID_MASK,
1394 					hw_rx_obj->id);
1395 	}
1396 
1397 	/* CANFD */
1398 	if (hw_rx_obj->flags & MCP251XFD_OBJ_FLAGS_FDF) {
1399 		u8 dlc;
1400 
1401 		if (hw_rx_obj->flags & MCP251XFD_OBJ_FLAGS_ESI)
1402 			cfd->flags |= CANFD_ESI;
1403 
1404 		if (hw_rx_obj->flags & MCP251XFD_OBJ_FLAGS_BRS)
1405 			cfd->flags |= CANFD_BRS;
1406 
1407 		dlc = FIELD_GET(MCP251XFD_OBJ_FLAGS_DLC, hw_rx_obj->flags);
1408 		cfd->len = can_dlc2len(get_canfd_dlc(dlc));
1409 	} else {
1410 		if (hw_rx_obj->flags & MCP251XFD_OBJ_FLAGS_RTR)
1411 			cfd->can_id |= CAN_RTR_FLAG;
1412 
1413 		cfd->len = get_can_dlc(FIELD_GET(MCP251XFD_OBJ_FLAGS_DLC,
1414 						 hw_rx_obj->flags));
1415 	}
1416 
1417 	memcpy(cfd->data, hw_rx_obj->data, cfd->len);
1418 }
1419 
1420 static int
1421 mcp251xfd_handle_rxif_one(struct mcp251xfd_priv *priv,
1422 			  struct mcp251xfd_rx_ring *ring,
1423 			  const struct mcp251xfd_hw_rx_obj_canfd *hw_rx_obj)
1424 {
1425 	struct net_device_stats *stats = &priv->ndev->stats;
1426 	struct sk_buff *skb;
1427 	struct canfd_frame *cfd;
1428 	int err;
1429 
1430 	if (hw_rx_obj->flags & MCP251XFD_OBJ_FLAGS_FDF)
1431 		skb = alloc_canfd_skb(priv->ndev, &cfd);
1432 	else
1433 		skb = alloc_can_skb(priv->ndev, (struct can_frame **)&cfd);
1434 
1435 	if (!cfd) {
1436 		stats->rx_dropped++;
1437 		return 0;
1438 	}
1439 
1440 	mcp251xfd_hw_rx_obj_to_skb(priv, hw_rx_obj, skb);
1441 	err = can_rx_offload_queue_sorted(&priv->offload, skb, hw_rx_obj->ts);
1442 	if (err)
1443 		stats->rx_fifo_errors++;
1444 
1445 	ring->tail++;
1446 
1447 	/* finally increment the RX pointer */
1448 	return regmap_update_bits(priv->map_reg,
1449 				  MCP251XFD_REG_FIFOCON(ring->fifo_nr),
1450 				  GENMASK(15, 8),
1451 				  MCP251XFD_REG_FIFOCON_UINC);
1452 }
1453 
1454 static inline int
1455 mcp251xfd_rx_obj_read(const struct mcp251xfd_priv *priv,
1456 		      const struct mcp251xfd_rx_ring *ring,
1457 		      struct mcp251xfd_hw_rx_obj_canfd *hw_rx_obj,
1458 		      const u8 offset, const u8 len)
1459 {
1460 	int err;
1461 
1462 	err = regmap_bulk_read(priv->map_rx,
1463 			       mcp251xfd_get_rx_obj_addr(ring, offset),
1464 			       hw_rx_obj,
1465 			       len * ring->obj_size / sizeof(u32));
1466 
1467 	return err;
1468 }
1469 
1470 static int
1471 mcp251xfd_handle_rxif_ring(struct mcp251xfd_priv *priv,
1472 			   struct mcp251xfd_rx_ring *ring)
1473 {
1474 	struct mcp251xfd_hw_rx_obj_canfd *hw_rx_obj = ring->obj;
1475 	u8 rx_tail, len;
1476 	int err, i;
1477 
1478 	err = mcp251xfd_rx_ring_update(priv, ring);
1479 	if (err)
1480 		return err;
1481 
1482 	while ((len = mcp251xfd_get_rx_linear_len(ring))) {
1483 		rx_tail = mcp251xfd_get_rx_tail(ring);
1484 
1485 		err = mcp251xfd_rx_obj_read(priv, ring, hw_rx_obj,
1486 					    rx_tail, len);
1487 		if (err)
1488 			return err;
1489 
1490 		for (i = 0; i < len; i++) {
1491 			err = mcp251xfd_handle_rxif_one(priv, ring,
1492 							(void *)hw_rx_obj +
1493 							i * ring->obj_size);
1494 			if (err)
1495 				return err;
1496 		}
1497 	}
1498 
1499 	return 0;
1500 }
1501 
1502 static int mcp251xfd_handle_rxif(struct mcp251xfd_priv *priv)
1503 {
1504 	struct mcp251xfd_rx_ring *ring;
1505 	int err, n;
1506 
1507 	mcp251xfd_for_each_rx_ring(priv, ring, n) {
1508 		err = mcp251xfd_handle_rxif_ring(priv, ring);
1509 		if (err)
1510 			return err;
1511 	}
1512 
1513 	return 0;
1514 }
1515 
1516 static inline int mcp251xfd_get_timestamp(const struct mcp251xfd_priv *priv,
1517 					  u32 *timestamp)
1518 {
1519 	return regmap_read(priv->map_reg, MCP251XFD_REG_TBC, timestamp);
1520 }
1521 
1522 static struct sk_buff *
1523 mcp251xfd_alloc_can_err_skb(const struct mcp251xfd_priv *priv,
1524 			    struct can_frame **cf, u32 *timestamp)
1525 {
1526 	int err;
1527 
1528 	err = mcp251xfd_get_timestamp(priv, timestamp);
1529 	if (err)
1530 		return NULL;
1531 
1532 	return alloc_can_err_skb(priv->ndev, cf);
1533 }
1534 
1535 static int mcp251xfd_handle_rxovif(struct mcp251xfd_priv *priv)
1536 {
1537 	struct net_device_stats *stats = &priv->ndev->stats;
1538 	struct mcp251xfd_rx_ring *ring;
1539 	struct sk_buff *skb;
1540 	struct can_frame *cf;
1541 	u32 timestamp, rxovif;
1542 	int err, i;
1543 
1544 	stats->rx_over_errors++;
1545 	stats->rx_errors++;
1546 
1547 	err = regmap_read(priv->map_reg, MCP251XFD_REG_RXOVIF, &rxovif);
1548 	if (err)
1549 		return err;
1550 
1551 	mcp251xfd_for_each_rx_ring(priv, ring, i) {
1552 		if (!(rxovif & BIT(ring->fifo_nr)))
1553 			continue;
1554 
1555 		/* If SERRIF is active, there was a RX MAB overflow. */
1556 		if (priv->regs_status.intf & MCP251XFD_REG_INT_SERRIF) {
1557 			netdev_info(priv->ndev,
1558 				    "RX-%d: MAB overflow detected.\n",
1559 				    ring->nr);
1560 		} else {
1561 			netdev_info(priv->ndev,
1562 				    "RX-%d: FIFO overflow.\n", ring->nr);
1563 		}
1564 
1565 		err = regmap_update_bits(priv->map_reg,
1566 					 MCP251XFD_REG_FIFOSTA(ring->fifo_nr),
1567 					 MCP251XFD_REG_FIFOSTA_RXOVIF,
1568 					 0x0);
1569 		if (err)
1570 			return err;
1571 	}
1572 
1573 	skb = mcp251xfd_alloc_can_err_skb(priv, &cf, &timestamp);
1574 	if (!skb)
1575 		return 0;
1576 
1577 	cf->can_id |= CAN_ERR_CRTL;
1578 	cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
1579 
1580 	err = can_rx_offload_queue_sorted(&priv->offload, skb, timestamp);
1581 	if (err)
1582 		stats->rx_fifo_errors++;
1583 
1584 	return 0;
1585 }
1586 
1587 static int mcp251xfd_handle_txatif(struct mcp251xfd_priv *priv)
1588 {
1589 	netdev_info(priv->ndev, "%s\n", __func__);
1590 
1591 	return 0;
1592 }
1593 
1594 static int mcp251xfd_handle_ivmif(struct mcp251xfd_priv *priv)
1595 {
1596 	struct net_device_stats *stats = &priv->ndev->stats;
1597 	u32 bdiag1, timestamp;
1598 	struct sk_buff *skb;
1599 	struct can_frame *cf = NULL;
1600 	int err;
1601 
1602 	err = mcp251xfd_get_timestamp(priv, &timestamp);
1603 	if (err)
1604 		return err;
1605 
1606 	err = regmap_read(priv->map_reg, MCP251XFD_REG_BDIAG1, &bdiag1);
1607 	if (err)
1608 		return err;
1609 
1610 	/* Write 0s to clear error bits, don't write 1s to non active
1611 	 * bits, as they will be set.
1612 	 */
1613 	err = regmap_write(priv->map_reg, MCP251XFD_REG_BDIAG1, 0x0);
1614 	if (err)
1615 		return err;
1616 
1617 	priv->can.can_stats.bus_error++;
1618 
1619 	skb = alloc_can_err_skb(priv->ndev, &cf);
1620 	if (cf)
1621 		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
1622 
1623 	/* Controller misconfiguration */
1624 	if (WARN_ON(bdiag1 & MCP251XFD_REG_BDIAG1_DLCMM))
1625 		netdev_err(priv->ndev,
1626 			   "recv'd DLC is larger than PLSIZE of FIFO element.");
1627 
1628 	/* RX errors */
1629 	if (bdiag1 & (MCP251XFD_REG_BDIAG1_DCRCERR |
1630 		      MCP251XFD_REG_BDIAG1_NCRCERR)) {
1631 		netdev_dbg(priv->ndev, "CRC error\n");
1632 
1633 		stats->rx_errors++;
1634 		if (cf)
1635 			cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
1636 	}
1637 	if (bdiag1 & (MCP251XFD_REG_BDIAG1_DSTUFERR |
1638 		      MCP251XFD_REG_BDIAG1_NSTUFERR)) {
1639 		netdev_dbg(priv->ndev, "Stuff error\n");
1640 
1641 		stats->rx_errors++;
1642 		if (cf)
1643 			cf->data[2] |= CAN_ERR_PROT_STUFF;
1644 	}
1645 	if (bdiag1 & (MCP251XFD_REG_BDIAG1_DFORMERR |
1646 		      MCP251XFD_REG_BDIAG1_NFORMERR)) {
1647 		netdev_dbg(priv->ndev, "Format error\n");
1648 
1649 		stats->rx_errors++;
1650 		if (cf)
1651 			cf->data[2] |= CAN_ERR_PROT_FORM;
1652 	}
1653 
1654 	/* TX errors */
1655 	if (bdiag1 & MCP251XFD_REG_BDIAG1_NACKERR) {
1656 		netdev_dbg(priv->ndev, "NACK error\n");
1657 
1658 		stats->tx_errors++;
1659 		if (cf) {
1660 			cf->can_id |= CAN_ERR_ACK;
1661 			cf->data[2] |= CAN_ERR_PROT_TX;
1662 		}
1663 	}
1664 	if (bdiag1 & (MCP251XFD_REG_BDIAG1_DBIT1ERR |
1665 		      MCP251XFD_REG_BDIAG1_NBIT1ERR)) {
1666 		netdev_dbg(priv->ndev, "Bit1 error\n");
1667 
1668 		stats->tx_errors++;
1669 		if (cf)
1670 			cf->data[2] |= CAN_ERR_PROT_TX | CAN_ERR_PROT_BIT1;
1671 	}
1672 	if (bdiag1 & (MCP251XFD_REG_BDIAG1_DBIT0ERR |
1673 		      MCP251XFD_REG_BDIAG1_NBIT0ERR)) {
1674 		netdev_dbg(priv->ndev, "Bit0 error\n");
1675 
1676 		stats->tx_errors++;
1677 		if (cf)
1678 			cf->data[2] |= CAN_ERR_PROT_TX | CAN_ERR_PROT_BIT0;
1679 	}
1680 
1681 	if (!cf)
1682 		return 0;
1683 
1684 	err = can_rx_offload_queue_sorted(&priv->offload, skb, timestamp);
1685 	if (err)
1686 		stats->rx_fifo_errors++;
1687 
1688 	return 0;
1689 }
1690 
1691 static int mcp251xfd_handle_cerrif(struct mcp251xfd_priv *priv)
1692 {
1693 	struct net_device_stats *stats = &priv->ndev->stats;
1694 	struct sk_buff *skb;
1695 	struct can_frame *cf = NULL;
1696 	enum can_state new_state, rx_state, tx_state;
1697 	u32 trec, timestamp;
1698 	int err;
1699 
1700 	err = regmap_read(priv->map_reg, MCP251XFD_REG_TREC, &trec);
1701 	if (err)
1702 		return err;
1703 
1704 	if (trec & MCP251XFD_REG_TREC_TXBO)
1705 		tx_state = CAN_STATE_BUS_OFF;
1706 	else if (trec & MCP251XFD_REG_TREC_TXBP)
1707 		tx_state = CAN_STATE_ERROR_PASSIVE;
1708 	else if (trec & MCP251XFD_REG_TREC_TXWARN)
1709 		tx_state = CAN_STATE_ERROR_WARNING;
1710 	else
1711 		tx_state = CAN_STATE_ERROR_ACTIVE;
1712 
1713 	if (trec & MCP251XFD_REG_TREC_RXBP)
1714 		rx_state = CAN_STATE_ERROR_PASSIVE;
1715 	else if (trec & MCP251XFD_REG_TREC_RXWARN)
1716 		rx_state = CAN_STATE_ERROR_WARNING;
1717 	else
1718 		rx_state = CAN_STATE_ERROR_ACTIVE;
1719 
1720 	new_state = max(tx_state, rx_state);
1721 	if (new_state == priv->can.state)
1722 		return 0;
1723 
1724 	/* The skb allocation might fail, but can_change_state()
1725 	 * handles cf == NULL.
1726 	 */
1727 	skb = mcp251xfd_alloc_can_err_skb(priv, &cf, &timestamp);
1728 	can_change_state(priv->ndev, cf, tx_state, rx_state);
1729 
1730 	if (new_state == CAN_STATE_BUS_OFF) {
1731 		/* As we're going to switch off the chip now, let's
1732 		 * save the error counters and return them to
1733 		 * userspace, if do_get_berr_counter() is called while
1734 		 * the chip is in Bus Off.
1735 		 */
1736 		err = __mcp251xfd_get_berr_counter(priv->ndev, &priv->bec);
1737 		if (err)
1738 			return err;
1739 
1740 		mcp251xfd_chip_stop(priv, CAN_STATE_BUS_OFF);
1741 		can_bus_off(priv->ndev);
1742 	}
1743 
1744 	if (!skb)
1745 		return 0;
1746 
1747 	if (new_state != CAN_STATE_BUS_OFF) {
1748 		struct can_berr_counter bec;
1749 
1750 		err = mcp251xfd_get_berr_counter(priv->ndev, &bec);
1751 		if (err)
1752 			return err;
1753 		cf->data[6] = bec.txerr;
1754 		cf->data[7] = bec.rxerr;
1755 	}
1756 
1757 	err = can_rx_offload_queue_sorted(&priv->offload, skb, timestamp);
1758 	if (err)
1759 		stats->rx_fifo_errors++;
1760 
1761 	return 0;
1762 }
1763 
1764 static int
1765 mcp251xfd_handle_modif(const struct mcp251xfd_priv *priv, bool *set_normal_mode)
1766 {
1767 	const u8 mode_reference = mcp251xfd_get_normal_mode(priv);
1768 	u8 mode;
1769 	int err;
1770 
1771 	err = mcp251xfd_chip_get_mode(priv, &mode);
1772 	if (err)
1773 		return err;
1774 
1775 	if (mode == mode_reference) {
1776 		netdev_dbg(priv->ndev,
1777 			   "Controller changed into %s Mode (%u).\n",
1778 			   mcp251xfd_get_mode_str(mode), mode);
1779 		return 0;
1780 	}
1781 
1782 	/* According to MCP2517FD errata DS80000792B 1., during a TX
1783 	 * MAB underflow, the controller will transition to Restricted
1784 	 * Operation Mode or Listen Only Mode (depending on SERR2LOM).
1785 	 *
1786 	 * However this is not always the case. If SERR2LOM is
1787 	 * configured for Restricted Operation Mode (SERR2LOM not set)
1788 	 * the MCP2517FD will sometimes transition to Listen Only Mode
1789 	 * first. When polling this bit we see that it will transition
1790 	 * to Restricted Operation Mode shortly after.
1791 	 */
1792 	if ((priv->devtype_data.quirks & MCP251XFD_QUIRK_MAB_NO_WARN) &&
1793 	    (mode == MCP251XFD_REG_CON_MODE_RESTRICTED ||
1794 	     mode == MCP251XFD_REG_CON_MODE_LISTENONLY))
1795 		netdev_dbg(priv->ndev,
1796 			   "Controller changed into %s Mode (%u).\n",
1797 			   mcp251xfd_get_mode_str(mode), mode);
1798 	else
1799 		netdev_err(priv->ndev,
1800 			   "Controller changed into %s Mode (%u).\n",
1801 			   mcp251xfd_get_mode_str(mode), mode);
1802 
1803 	/* After the application requests Normal mode, the Controller
1804 	 * will automatically attempt to retransmit the message that
1805 	 * caused the TX MAB underflow.
1806 	 *
1807 	 * However, if there is an ECC error in the TX-RAM, we first
1808 	 * have to reload the tx-object before requesting Normal
1809 	 * mode. This is done later in mcp251xfd_handle_eccif().
1810 	 */
1811 	if (priv->regs_status.intf & MCP251XFD_REG_INT_ECCIF) {
1812 		*set_normal_mode = true;
1813 		return 0;
1814 	}
1815 
1816 	return mcp251xfd_chip_set_normal_mode_nowait(priv);
1817 }
1818 
1819 static int mcp251xfd_handle_serrif(struct mcp251xfd_priv *priv)
1820 {
1821 	struct mcp251xfd_ecc *ecc = &priv->ecc;
1822 	struct net_device_stats *stats = &priv->ndev->stats;
1823 	bool handled = false;
1824 
1825 	/* TX MAB underflow
1826 	 *
1827 	 * According to MCP2517FD Errata DS80000792B 1. a TX MAB
1828 	 * underflow is indicated by SERRIF and MODIF.
1829 	 *
1830 	 * In addition to the effects mentioned in the Errata, there
1831 	 * are Bus Errors due to the aborted CAN frame, so a IVMIF
1832 	 * will be seen as well.
1833 	 *
1834 	 * Sometimes there is an ECC error in the TX-RAM, which leads
1835 	 * to a TX MAB underflow.
1836 	 *
1837 	 * However, probably due to a race condition, there is no
1838 	 * associated MODIF pending.
1839 	 *
1840 	 * Further, there are situations, where the SERRIF is caused
1841 	 * by an ECC error in the TX-RAM, but not even the ECCIF is
1842 	 * set. This only seems to happen _after_ the first occurrence
1843 	 * of a ECCIF (which is tracked in ecc->cnt).
1844 	 *
1845 	 * Treat all as a known system errors..
1846 	 */
1847 	if ((priv->regs_status.intf & MCP251XFD_REG_INT_MODIF &&
1848 	     priv->regs_status.intf & MCP251XFD_REG_INT_IVMIF) ||
1849 	    priv->regs_status.intf & MCP251XFD_REG_INT_ECCIF ||
1850 	    ecc->cnt) {
1851 		const char *msg;
1852 
1853 		if (priv->regs_status.intf & MCP251XFD_REG_INT_ECCIF ||
1854 		    ecc->cnt)
1855 			msg = "TX MAB underflow due to ECC error detected.";
1856 		else
1857 			msg = "TX MAB underflow detected.";
1858 
1859 		if (priv->devtype_data.quirks & MCP251XFD_QUIRK_MAB_NO_WARN)
1860 			netdev_dbg(priv->ndev, "%s\n", msg);
1861 		else
1862 			netdev_info(priv->ndev, "%s\n", msg);
1863 
1864 		stats->tx_aborted_errors++;
1865 		stats->tx_errors++;
1866 		handled = true;
1867 	}
1868 
1869 	/* RX MAB overflow
1870 	 *
1871 	 * According to MCP2517FD Errata DS80000792B 1. a RX MAB
1872 	 * overflow is indicated by SERRIF.
1873 	 *
1874 	 * In addition to the effects mentioned in the Errata, (most
1875 	 * of the times) a RXOVIF is raised, if the FIFO that is being
1876 	 * received into has the RXOVIE activated (and we have enabled
1877 	 * RXOVIE on all FIFOs).
1878 	 *
1879 	 * Sometimes there is no RXOVIF just a RXIF is pending.
1880 	 *
1881 	 * Treat all as a known system errors..
1882 	 */
1883 	if (priv->regs_status.intf & MCP251XFD_REG_INT_RXOVIF ||
1884 	    priv->regs_status.intf & MCP251XFD_REG_INT_RXIF) {
1885 		stats->rx_dropped++;
1886 		handled = true;
1887 	}
1888 
1889 	if (!handled)
1890 		netdev_err(priv->ndev,
1891 			   "Unhandled System Error Interrupt (intf=0x%08x)!\n",
1892 			   priv->regs_status.intf);
1893 
1894 	return 0;
1895 }
1896 
1897 static int
1898 mcp251xfd_handle_eccif_recover(struct mcp251xfd_priv *priv, u8 nr)
1899 {
1900 	struct mcp251xfd_tx_ring *tx_ring = priv->tx;
1901 	struct mcp251xfd_ecc *ecc = &priv->ecc;
1902 	struct mcp251xfd_tx_obj *tx_obj;
1903 	u8 chip_tx_tail, tx_tail, offset;
1904 	u16 addr;
1905 	int err;
1906 
1907 	addr = FIELD_GET(MCP251XFD_REG_ECCSTAT_ERRADDR_MASK, ecc->ecc_stat);
1908 
1909 	err = mcp251xfd_tx_tail_get_from_chip(priv, &chip_tx_tail);
1910 	if (err)
1911 		return err;
1912 
1913 	tx_tail = mcp251xfd_get_tx_tail(tx_ring);
1914 	offset = (nr - chip_tx_tail) & (tx_ring->obj_num - 1);
1915 
1916 	/* Bail out if one of the following is met:
1917 	 * - tx_tail information is inconsistent
1918 	 * - for mcp2517fd: offset not 0
1919 	 * - for mcp2518fd: offset not 0 or 1
1920 	 */
1921 	if (chip_tx_tail != tx_tail ||
1922 	    !(offset == 0 || (offset == 1 && mcp251xfd_is_2518(priv)))) {
1923 		netdev_err(priv->ndev,
1924 			   "ECC Error information inconsistent (addr=0x%04x, nr=%d, tx_tail=0x%08x(%d), chip_tx_tail=%d, offset=%d).\n",
1925 			   addr, nr, tx_ring->tail, tx_tail, chip_tx_tail,
1926 			   offset);
1927 		return -EINVAL;
1928 	}
1929 
1930 	netdev_info(priv->ndev,
1931 		    "Recovering %s ECC Error at address 0x%04x (in TX-RAM, tx_obj=%d, tx_tail=0x%08x(%d), offset=%d).\n",
1932 		    ecc->ecc_stat & MCP251XFD_REG_ECCSTAT_SECIF ?
1933 		    "Single" : "Double",
1934 		    addr, nr, tx_ring->tail, tx_tail, offset);
1935 
1936 	/* reload tx_obj into controller RAM ... */
1937 	tx_obj = &tx_ring->obj[nr];
1938 	err = spi_sync_transfer(priv->spi, tx_obj->xfer, 1);
1939 	if (err)
1940 		return err;
1941 
1942 	/* ... and trigger retransmit */
1943 	return mcp251xfd_chip_set_normal_mode(priv);
1944 }
1945 
1946 static int
1947 mcp251xfd_handle_eccif(struct mcp251xfd_priv *priv, bool set_normal_mode)
1948 {
1949 	struct mcp251xfd_ecc *ecc = &priv->ecc;
1950 	const char *msg;
1951 	bool in_tx_ram;
1952 	u32 ecc_stat;
1953 	u16 addr;
1954 	u8 nr;
1955 	int err;
1956 
1957 	err = regmap_read(priv->map_reg, MCP251XFD_REG_ECCSTAT, &ecc_stat);
1958 	if (err)
1959 		return err;
1960 
1961 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_ECCSTAT,
1962 				 MCP251XFD_REG_ECCSTAT_IF_MASK, ~ecc_stat);
1963 	if (err)
1964 		return err;
1965 
1966 	/* Check if ECC error occurred in TX-RAM */
1967 	addr = FIELD_GET(MCP251XFD_REG_ECCSTAT_ERRADDR_MASK, ecc_stat);
1968 	err = mcp251xfd_get_tx_nr_by_addr(priv->tx, &nr, addr);
1969 	if (!err)
1970 		in_tx_ram = true;
1971 	else if (err == -ENOENT)
1972 		in_tx_ram = false;
1973 	else
1974 		return err;
1975 
1976 	/* Errata Reference:
1977 	 * mcp2517fd: DS80000789B, mcp2518fd: DS80000792C 2.
1978 	 *
1979 	 * ECC single error correction does not work in all cases:
1980 	 *
1981 	 * Fix/Work Around:
1982 	 * Enable single error correction and double error detection
1983 	 * interrupts by setting SECIE and DEDIE. Handle SECIF as a
1984 	 * detection interrupt and do not rely on the error
1985 	 * correction. Instead, handle both interrupts as a
1986 	 * notification that the RAM word at ERRADDR was corrupted.
1987 	 */
1988 	if (ecc_stat & MCP251XFD_REG_ECCSTAT_SECIF)
1989 		msg = "Single ECC Error detected at address";
1990 	else if (ecc_stat & MCP251XFD_REG_ECCSTAT_DEDIF)
1991 		msg = "Double ECC Error detected at address";
1992 	else
1993 		return -EINVAL;
1994 
1995 	if (!in_tx_ram) {
1996 		ecc->ecc_stat = 0;
1997 
1998 		netdev_notice(priv->ndev, "%s 0x%04x.\n", msg, addr);
1999 	} else {
2000 		/* Re-occurring error? */
2001 		if (ecc->ecc_stat == ecc_stat) {
2002 			ecc->cnt++;
2003 		} else {
2004 			ecc->ecc_stat = ecc_stat;
2005 			ecc->cnt = 1;
2006 		}
2007 
2008 		netdev_info(priv->ndev,
2009 			    "%s 0x%04x (in TX-RAM, tx_obj=%d), occurred %d time%s.\n",
2010 			    msg, addr, nr, ecc->cnt, ecc->cnt > 1 ? "s" : "");
2011 
2012 		if (ecc->cnt >= MCP251XFD_ECC_CNT_MAX)
2013 			return mcp251xfd_handle_eccif_recover(priv, nr);
2014 	}
2015 
2016 	if (set_normal_mode)
2017 		return mcp251xfd_chip_set_normal_mode_nowait(priv);
2018 
2019 	return 0;
2020 }
2021 
2022 static int mcp251xfd_handle_spicrcif(struct mcp251xfd_priv *priv)
2023 {
2024 	int err;
2025 	u32 crc;
2026 
2027 	err = regmap_read(priv->map_reg, MCP251XFD_REG_CRC, &crc);
2028 	if (err)
2029 		return err;
2030 
2031 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_CRC,
2032 				 MCP251XFD_REG_CRC_IF_MASK,
2033 				 ~crc);
2034 	if (err)
2035 		return err;
2036 
2037 	if (crc & MCP251XFD_REG_CRC_FERRIF)
2038 		netdev_notice(priv->ndev, "CRC write command format error.\n");
2039 	else if (crc & MCP251XFD_REG_CRC_CRCERRIF)
2040 		netdev_notice(priv->ndev,
2041 			      "CRC write error detected. CRC=0x%04lx.\n",
2042 			      FIELD_GET(MCP251XFD_REG_CRC_MASK, crc));
2043 
2044 	return 0;
2045 }
2046 
2047 #define mcp251xfd_handle(priv, irq, ...) \
2048 ({ \
2049 	struct mcp251xfd_priv *_priv = (priv); \
2050 	int err; \
2051 \
2052 	err = mcp251xfd_handle_##irq(_priv, ## __VA_ARGS__); \
2053 	if (err) \
2054 		netdev_err(_priv->ndev, \
2055 			"IRQ handler mcp251xfd_handle_%s() returned %d.\n", \
2056 			__stringify(irq), err); \
2057 	err; \
2058 })
2059 
2060 static irqreturn_t mcp251xfd_irq(int irq, void *dev_id)
2061 {
2062 	struct mcp251xfd_priv *priv = dev_id;
2063 	irqreturn_t handled = IRQ_NONE;
2064 	int err;
2065 
2066 	if (priv->rx_int)
2067 		do {
2068 			int rx_pending;
2069 
2070 			rx_pending = gpiod_get_value_cansleep(priv->rx_int);
2071 			if (!rx_pending)
2072 				break;
2073 
2074 			err = mcp251xfd_handle(priv, rxif);
2075 			if (err)
2076 				goto out_fail;
2077 
2078 			handled = IRQ_HANDLED;
2079 		} while (1);
2080 
2081 	do {
2082 		u32 intf_pending, intf_pending_clearable;
2083 		bool set_normal_mode = false;
2084 
2085 		err = regmap_bulk_read(priv->map_reg, MCP251XFD_REG_INT,
2086 				       &priv->regs_status,
2087 				       sizeof(priv->regs_status) /
2088 				       sizeof(u32));
2089 		if (err)
2090 			goto out_fail;
2091 
2092 		intf_pending = FIELD_GET(MCP251XFD_REG_INT_IF_MASK,
2093 					 priv->regs_status.intf) &
2094 			FIELD_GET(MCP251XFD_REG_INT_IE_MASK,
2095 				  priv->regs_status.intf);
2096 
2097 		if (!(intf_pending))
2098 			return handled;
2099 
2100 		/* Some interrupts must be ACKed in the
2101 		 * MCP251XFD_REG_INT register.
2102 		 * - First ACK then handle, to avoid lost-IRQ race
2103 		 *   condition on fast re-occurring interrupts.
2104 		 * - Write "0" to clear active IRQs, "1" to all other,
2105 		 *   to avoid r/m/w race condition on the
2106 		 *   MCP251XFD_REG_INT register.
2107 		 */
2108 		intf_pending_clearable = intf_pending &
2109 			MCP251XFD_REG_INT_IF_CLEARABLE_MASK;
2110 		if (intf_pending_clearable) {
2111 			err = regmap_update_bits(priv->map_reg,
2112 						 MCP251XFD_REG_INT,
2113 						 MCP251XFD_REG_INT_IF_MASK,
2114 						 ~intf_pending_clearable);
2115 			if (err)
2116 				goto out_fail;
2117 		}
2118 
2119 		if (intf_pending & MCP251XFD_REG_INT_MODIF) {
2120 			err = mcp251xfd_handle(priv, modif, &set_normal_mode);
2121 			if (err)
2122 				goto out_fail;
2123 		}
2124 
2125 		if (intf_pending & MCP251XFD_REG_INT_RXIF) {
2126 			err = mcp251xfd_handle(priv, rxif);
2127 			if (err)
2128 				goto out_fail;
2129 		}
2130 
2131 		if (intf_pending & MCP251XFD_REG_INT_TEFIF) {
2132 			err = mcp251xfd_handle(priv, tefif);
2133 			if (err)
2134 				goto out_fail;
2135 		}
2136 
2137 		if (intf_pending & MCP251XFD_REG_INT_RXOVIF) {
2138 			err = mcp251xfd_handle(priv, rxovif);
2139 			if (err)
2140 				goto out_fail;
2141 		}
2142 
2143 		if (intf_pending & MCP251XFD_REG_INT_TXATIF) {
2144 			err = mcp251xfd_handle(priv, txatif);
2145 			if (err)
2146 				goto out_fail;
2147 		}
2148 
2149 		if (intf_pending & MCP251XFD_REG_INT_IVMIF) {
2150 			err = mcp251xfd_handle(priv, ivmif);
2151 			if (err)
2152 				goto out_fail;
2153 		}
2154 
2155 		if (intf_pending & MCP251XFD_REG_INT_SERRIF) {
2156 			err = mcp251xfd_handle(priv, serrif);
2157 			if (err)
2158 				goto out_fail;
2159 		}
2160 
2161 		if (intf_pending & MCP251XFD_REG_INT_ECCIF) {
2162 			err = mcp251xfd_handle(priv, eccif, set_normal_mode);
2163 			if (err)
2164 				goto out_fail;
2165 		}
2166 
2167 		if (intf_pending & MCP251XFD_REG_INT_SPICRCIF) {
2168 			err = mcp251xfd_handle(priv, spicrcif);
2169 			if (err)
2170 				goto out_fail;
2171 		}
2172 
2173 		/* On the MCP2527FD and MCP2518FD, we don't get a
2174 		 * CERRIF IRQ on the transition TX ERROR_WARNING -> TX
2175 		 * ERROR_ACTIVE.
2176 		 */
2177 		if (intf_pending & MCP251XFD_REG_INT_CERRIF ||
2178 		    priv->can.state > CAN_STATE_ERROR_ACTIVE) {
2179 			err = mcp251xfd_handle(priv, cerrif);
2180 			if (err)
2181 				goto out_fail;
2182 
2183 			/* In Bus Off we completely shut down the
2184 			 * controller. Every subsequent register read
2185 			 * will read bogus data, and if
2186 			 * MCP251XFD_QUIRK_CRC_REG is enabled the CRC
2187 			 * check will fail, too. So leave IRQ handler
2188 			 * directly.
2189 			 */
2190 			if (priv->can.state == CAN_STATE_BUS_OFF)
2191 				return IRQ_HANDLED;
2192 		}
2193 
2194 		handled = IRQ_HANDLED;
2195 	} while (1);
2196 
2197  out_fail:
2198 	netdev_err(priv->ndev, "IRQ handler returned %d (intf=0x%08x).\n",
2199 		   err, priv->regs_status.intf);
2200 	mcp251xfd_chip_interrupts_disable(priv);
2201 
2202 	return handled;
2203 }
2204 
2205 static inline struct
2206 mcp251xfd_tx_obj *mcp251xfd_get_tx_obj_next(struct mcp251xfd_tx_ring *tx_ring)
2207 {
2208 	u8 tx_head;
2209 
2210 	tx_head = mcp251xfd_get_tx_head(tx_ring);
2211 
2212 	return &tx_ring->obj[tx_head];
2213 }
2214 
2215 static void
2216 mcp251xfd_tx_obj_from_skb(const struct mcp251xfd_priv *priv,
2217 			  struct mcp251xfd_tx_obj *tx_obj,
2218 			  const struct sk_buff *skb,
2219 			  unsigned int seq)
2220 {
2221 	const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
2222 	struct mcp251xfd_hw_tx_obj_raw *hw_tx_obj;
2223 	union mcp251xfd_tx_obj_load_buf *load_buf;
2224 	u8 dlc;
2225 	u32 id, flags;
2226 	int offset, len;
2227 
2228 	if (cfd->can_id & CAN_EFF_FLAG) {
2229 		u32 sid, eid;
2230 
2231 		sid = FIELD_GET(MCP251XFD_REG_FRAME_EFF_SID_MASK, cfd->can_id);
2232 		eid = FIELD_GET(MCP251XFD_REG_FRAME_EFF_EID_MASK, cfd->can_id);
2233 
2234 		id = FIELD_PREP(MCP251XFD_OBJ_ID_EID_MASK, eid) |
2235 			FIELD_PREP(MCP251XFD_OBJ_ID_SID_MASK, sid);
2236 
2237 		flags = MCP251XFD_OBJ_FLAGS_IDE;
2238 	} else {
2239 		id = FIELD_PREP(MCP251XFD_OBJ_ID_SID_MASK, cfd->can_id);
2240 		flags = 0;
2241 	}
2242 
2243 	/* Use the MCP2518FD mask even on the MCP2517FD. It doesn't
2244 	 * harm, only the lower 7 bits will be transferred into the
2245 	 * TEF object.
2246 	 */
2247 	dlc = can_len2dlc(cfd->len);
2248 	flags |= FIELD_PREP(MCP251XFD_OBJ_FLAGS_SEQ_MCP2518FD_MASK, seq) |
2249 		FIELD_PREP(MCP251XFD_OBJ_FLAGS_DLC, dlc);
2250 
2251 	if (cfd->can_id & CAN_RTR_FLAG)
2252 		flags |= MCP251XFD_OBJ_FLAGS_RTR;
2253 
2254 	/* CANFD */
2255 	if (can_is_canfd_skb(skb)) {
2256 		if (cfd->flags & CANFD_ESI)
2257 			flags |= MCP251XFD_OBJ_FLAGS_ESI;
2258 
2259 		flags |= MCP251XFD_OBJ_FLAGS_FDF;
2260 
2261 		if (cfd->flags & CANFD_BRS)
2262 			flags |= MCP251XFD_OBJ_FLAGS_BRS;
2263 	}
2264 
2265 	load_buf = &tx_obj->buf;
2266 	if (priv->devtype_data.quirks & MCP251XFD_QUIRK_CRC_TX)
2267 		hw_tx_obj = &load_buf->crc.hw_tx_obj;
2268 	else
2269 		hw_tx_obj = &load_buf->nocrc.hw_tx_obj;
2270 
2271 	put_unaligned_le32(id, &hw_tx_obj->id);
2272 	put_unaligned_le32(flags, &hw_tx_obj->flags);
2273 
2274 	/* Clear data at end of CAN frame */
2275 	offset = round_down(cfd->len, sizeof(u32));
2276 	len = round_up(can_dlc2len(dlc), sizeof(u32)) - offset;
2277 	if (MCP251XFD_SANITIZE_CAN && len)
2278 		memset(hw_tx_obj->data + offset, 0x0, len);
2279 	memcpy(hw_tx_obj->data, cfd->data, cfd->len);
2280 
2281 	/* Number of bytes to be written into the RAM of the controller */
2282 	len = sizeof(hw_tx_obj->id) + sizeof(hw_tx_obj->flags);
2283 	if (MCP251XFD_SANITIZE_CAN)
2284 		len += round_up(can_dlc2len(dlc), sizeof(u32));
2285 	else
2286 		len += round_up(cfd->len, sizeof(u32));
2287 
2288 	if (priv->devtype_data.quirks & MCP251XFD_QUIRK_CRC_TX) {
2289 		u16 crc;
2290 
2291 		mcp251xfd_spi_cmd_crc_set_len_in_ram(&load_buf->crc.cmd,
2292 						     len);
2293 		/* CRC */
2294 		len += sizeof(load_buf->crc.cmd);
2295 		crc = mcp251xfd_crc16_compute(&load_buf->crc, len);
2296 		put_unaligned_be16(crc, (void *)load_buf + len);
2297 
2298 		/* Total length */
2299 		len += sizeof(load_buf->crc.crc);
2300 	} else {
2301 		len += sizeof(load_buf->nocrc.cmd);
2302 	}
2303 
2304 	tx_obj->xfer[0].len = len;
2305 }
2306 
2307 static int mcp251xfd_tx_obj_write(const struct mcp251xfd_priv *priv,
2308 				  struct mcp251xfd_tx_obj *tx_obj)
2309 {
2310 	return spi_async(priv->spi, &tx_obj->msg);
2311 }
2312 
2313 static bool mcp251xfd_tx_busy(const struct mcp251xfd_priv *priv,
2314 			      struct mcp251xfd_tx_ring *tx_ring)
2315 {
2316 	if (mcp251xfd_get_tx_free(tx_ring) > 0)
2317 		return false;
2318 
2319 	netif_stop_queue(priv->ndev);
2320 
2321 	/* Memory barrier before checking tx_free (head and tail) */
2322 	smp_mb();
2323 
2324 	if (mcp251xfd_get_tx_free(tx_ring) == 0) {
2325 		netdev_dbg(priv->ndev,
2326 			   "Stopping tx-queue (tx_head=0x%08x, tx_tail=0x%08x, len=%d).\n",
2327 			   tx_ring->head, tx_ring->tail,
2328 			   tx_ring->head - tx_ring->tail);
2329 
2330 		return true;
2331 	}
2332 
2333 	netif_start_queue(priv->ndev);
2334 
2335 	return false;
2336 }
2337 
2338 static netdev_tx_t mcp251xfd_start_xmit(struct sk_buff *skb,
2339 					struct net_device *ndev)
2340 {
2341 	struct mcp251xfd_priv *priv = netdev_priv(ndev);
2342 	struct mcp251xfd_tx_ring *tx_ring = priv->tx;
2343 	struct mcp251xfd_tx_obj *tx_obj;
2344 	u8 tx_head;
2345 	int err;
2346 
2347 	if (can_dropped_invalid_skb(ndev, skb))
2348 		return NETDEV_TX_OK;
2349 
2350 	if (mcp251xfd_tx_busy(priv, tx_ring))
2351 		return NETDEV_TX_BUSY;
2352 
2353 	tx_obj = mcp251xfd_get_tx_obj_next(tx_ring);
2354 	mcp251xfd_tx_obj_from_skb(priv, tx_obj, skb, tx_ring->head);
2355 
2356 	/* Stop queue if we occupy the complete TX FIFO */
2357 	tx_head = mcp251xfd_get_tx_head(tx_ring);
2358 	tx_ring->head++;
2359 	if (tx_ring->head - tx_ring->tail >= tx_ring->obj_num)
2360 		netif_stop_queue(ndev);
2361 
2362 	can_put_echo_skb(skb, ndev, tx_head);
2363 
2364 	err = mcp251xfd_tx_obj_write(priv, tx_obj);
2365 	if (err)
2366 		goto out_err;
2367 
2368 	return NETDEV_TX_OK;
2369 
2370  out_err:
2371 	netdev_err(priv->ndev, "ERROR in %s: %d\n", __func__, err);
2372 
2373 	return NETDEV_TX_OK;
2374 }
2375 
2376 static int mcp251xfd_open(struct net_device *ndev)
2377 {
2378 	struct mcp251xfd_priv *priv = netdev_priv(ndev);
2379 	const struct spi_device *spi = priv->spi;
2380 	int err;
2381 
2382 	err = pm_runtime_get_sync(ndev->dev.parent);
2383 	if (err < 0) {
2384 		pm_runtime_put_noidle(ndev->dev.parent);
2385 		return err;
2386 	}
2387 
2388 	err = open_candev(ndev);
2389 	if (err)
2390 		goto out_pm_runtime_put;
2391 
2392 	err = mcp251xfd_ring_alloc(priv);
2393 	if (err)
2394 		goto out_close_candev;
2395 
2396 	err = mcp251xfd_transceiver_enable(priv);
2397 	if (err)
2398 		goto out_mcp251xfd_ring_free;
2399 
2400 	err = mcp251xfd_chip_start(priv);
2401 	if (err)
2402 		goto out_transceiver_disable;
2403 
2404 	can_rx_offload_enable(&priv->offload);
2405 
2406 	err = request_threaded_irq(spi->irq, NULL, mcp251xfd_irq,
2407 				   IRQF_ONESHOT, dev_name(&spi->dev),
2408 				   priv);
2409 	if (err)
2410 		goto out_can_rx_offload_disable;
2411 
2412 	err = mcp251xfd_chip_interrupts_enable(priv);
2413 	if (err)
2414 		goto out_free_irq;
2415 
2416 	netif_start_queue(ndev);
2417 
2418 	return 0;
2419 
2420  out_free_irq:
2421 	free_irq(spi->irq, priv);
2422  out_can_rx_offload_disable:
2423 	can_rx_offload_disable(&priv->offload);
2424  out_transceiver_disable:
2425 	mcp251xfd_transceiver_disable(priv);
2426  out_mcp251xfd_ring_free:
2427 	mcp251xfd_ring_free(priv);
2428  out_close_candev:
2429 	close_candev(ndev);
2430  out_pm_runtime_put:
2431 	mcp251xfd_chip_stop(priv, CAN_STATE_STOPPED);
2432 	pm_runtime_put(ndev->dev.parent);
2433 
2434 	return err;
2435 }
2436 
2437 static int mcp251xfd_stop(struct net_device *ndev)
2438 {
2439 	struct mcp251xfd_priv *priv = netdev_priv(ndev);
2440 
2441 	netif_stop_queue(ndev);
2442 	mcp251xfd_chip_interrupts_disable(priv);
2443 	free_irq(ndev->irq, priv);
2444 	can_rx_offload_disable(&priv->offload);
2445 	mcp251xfd_chip_stop(priv, CAN_STATE_STOPPED);
2446 	mcp251xfd_transceiver_disable(priv);
2447 	mcp251xfd_ring_free(priv);
2448 	close_candev(ndev);
2449 
2450 	pm_runtime_put(ndev->dev.parent);
2451 
2452 	return 0;
2453 }
2454 
2455 static const struct net_device_ops mcp251xfd_netdev_ops = {
2456 	.ndo_open = mcp251xfd_open,
2457 	.ndo_stop = mcp251xfd_stop,
2458 	.ndo_start_xmit	= mcp251xfd_start_xmit,
2459 	.ndo_change_mtu = can_change_mtu,
2460 };
2461 
2462 static void
2463 mcp251xfd_register_quirks(struct mcp251xfd_priv *priv)
2464 {
2465 	const struct spi_device *spi = priv->spi;
2466 	const struct spi_controller *ctlr = spi->controller;
2467 
2468 	if (ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX)
2469 		priv->devtype_data.quirks |= MCP251XFD_QUIRK_HALF_DUPLEX;
2470 }
2471 
2472 static int mcp251xfd_register_chip_detect(struct mcp251xfd_priv *priv)
2473 {
2474 	const struct net_device *ndev = priv->ndev;
2475 	const struct mcp251xfd_devtype_data *devtype_data;
2476 	u32 osc;
2477 	int err;
2478 
2479 	/* The OSC_LPMEN is only supported on MCP2518FD, so use it to
2480 	 * autodetect the model.
2481 	 */
2482 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_OSC,
2483 				 MCP251XFD_REG_OSC_LPMEN,
2484 				 MCP251XFD_REG_OSC_LPMEN);
2485 	if (err)
2486 		return err;
2487 
2488 	err = regmap_read(priv->map_reg, MCP251XFD_REG_OSC, &osc);
2489 	if (err)
2490 		return err;
2491 
2492 	if (osc & MCP251XFD_REG_OSC_LPMEN)
2493 		devtype_data = &mcp251xfd_devtype_data_mcp2518fd;
2494 	else
2495 		devtype_data = &mcp251xfd_devtype_data_mcp2517fd;
2496 
2497 	if (!mcp251xfd_is_251X(priv) &&
2498 	    priv->devtype_data.model != devtype_data->model) {
2499 		netdev_info(ndev,
2500 			    "Detected %s, but firmware specifies a %s. Fixing up.",
2501 			    __mcp251xfd_get_model_str(devtype_data->model),
2502 			    mcp251xfd_get_model_str(priv));
2503 	}
2504 	priv->devtype_data = *devtype_data;
2505 
2506 	/* We need to preserve the Half Duplex Quirk. */
2507 	mcp251xfd_register_quirks(priv);
2508 
2509 	/* Re-init regmap with quirks of detected model. */
2510 	return mcp251xfd_regmap_init(priv);
2511 }
2512 
2513 static int mcp251xfd_register_check_rx_int(struct mcp251xfd_priv *priv)
2514 {
2515 	int err, rx_pending;
2516 
2517 	if (!priv->rx_int)
2518 		return 0;
2519 
2520 	err = mcp251xfd_chip_rx_int_enable(priv);
2521 	if (err)
2522 		return err;
2523 
2524 	/* Check if RX_INT is properly working. The RX_INT should not
2525 	 * be active after a softreset.
2526 	 */
2527 	rx_pending = gpiod_get_value_cansleep(priv->rx_int);
2528 
2529 	err = mcp251xfd_chip_rx_int_disable(priv);
2530 	if (err)
2531 		return err;
2532 
2533 	if (!rx_pending)
2534 		return 0;
2535 
2536 	netdev_info(priv->ndev,
2537 		    "RX_INT active after softreset, disabling RX_INT support.");
2538 	devm_gpiod_put(&priv->spi->dev, priv->rx_int);
2539 	priv->rx_int = NULL;
2540 
2541 	return 0;
2542 }
2543 
2544 static int
2545 mcp251xfd_register_get_dev_id(const struct mcp251xfd_priv *priv,
2546 			      u32 *dev_id, u32 *effective_speed_hz)
2547 {
2548 	struct mcp251xfd_map_buf_nocrc *buf_rx;
2549 	struct mcp251xfd_map_buf_nocrc *buf_tx;
2550 	struct spi_transfer xfer[2] = { };
2551 	int err;
2552 
2553 	buf_rx = kzalloc(sizeof(*buf_rx), GFP_KERNEL);
2554 	if (!buf_rx)
2555 		return -ENOMEM;
2556 
2557 	buf_tx = kzalloc(sizeof(*buf_tx), GFP_KERNEL);
2558 	if (!buf_tx) {
2559 		err = -ENOMEM;
2560 		goto out_kfree_buf_rx;
2561 	}
2562 
2563 	xfer[0].tx_buf = buf_tx;
2564 	xfer[0].len = sizeof(buf_tx->cmd);
2565 	xfer[1].rx_buf = buf_rx->data;
2566 	xfer[1].len = sizeof(dev_id);
2567 
2568 	mcp251xfd_spi_cmd_read_nocrc(&buf_tx->cmd, MCP251XFD_REG_DEVID);
2569 	err = spi_sync_transfer(priv->spi, xfer, ARRAY_SIZE(xfer));
2570 	if (err)
2571 		goto out_kfree_buf_tx;
2572 
2573 	*dev_id = be32_to_cpup((__be32 *)buf_rx->data);
2574 	*effective_speed_hz = xfer->effective_speed_hz;
2575 
2576  out_kfree_buf_tx:
2577 	kfree(buf_tx);
2578  out_kfree_buf_rx:
2579 	kfree(buf_rx);
2580 
2581 	return 0;
2582 }
2583 
2584 #define MCP251XFD_QUIRK_ACTIVE(quirk) \
2585 	(priv->devtype_data.quirks & MCP251XFD_QUIRK_##quirk ? '+' : '-')
2586 
2587 static int
2588 mcp251xfd_register_done(const struct mcp251xfd_priv *priv)
2589 {
2590 	u32 dev_id, effective_speed_hz;
2591 	int err;
2592 
2593 	err = mcp251xfd_register_get_dev_id(priv, &dev_id,
2594 					    &effective_speed_hz);
2595 	if (err)
2596 		return err;
2597 
2598 	netdev_info(priv->ndev,
2599 		    "%s rev%lu.%lu (%cRX_INT %cMAB_NO_WARN %cCRC_REG %cCRC_RX %cCRC_TX %cECC %cHD c:%u.%02uMHz m:%u.%02uMHz r:%u.%02uMHz e:%u.%02uMHz) successfully initialized.\n",
2600 		    mcp251xfd_get_model_str(priv),
2601 		    FIELD_GET(MCP251XFD_REG_DEVID_ID_MASK, dev_id),
2602 		    FIELD_GET(MCP251XFD_REG_DEVID_REV_MASK, dev_id),
2603 		    priv->rx_int ? '+' : '-',
2604 		    MCP251XFD_QUIRK_ACTIVE(MAB_NO_WARN),
2605 		    MCP251XFD_QUIRK_ACTIVE(CRC_REG),
2606 		    MCP251XFD_QUIRK_ACTIVE(CRC_RX),
2607 		    MCP251XFD_QUIRK_ACTIVE(CRC_TX),
2608 		    MCP251XFD_QUIRK_ACTIVE(ECC),
2609 		    MCP251XFD_QUIRK_ACTIVE(HALF_DUPLEX),
2610 		    priv->can.clock.freq / 1000000,
2611 		    priv->can.clock.freq % 1000000 / 1000 / 10,
2612 		    priv->spi_max_speed_hz_orig / 1000000,
2613 		    priv->spi_max_speed_hz_orig % 1000000 / 1000 / 10,
2614 		    priv->spi->max_speed_hz / 1000000,
2615 		    priv->spi->max_speed_hz % 1000000 / 1000 / 10,
2616 		    effective_speed_hz / 1000000,
2617 		    effective_speed_hz % 1000000 / 1000 / 10);
2618 
2619 	return 0;
2620 }
2621 
2622 static int mcp251xfd_register(struct mcp251xfd_priv *priv)
2623 {
2624 	struct net_device *ndev = priv->ndev;
2625 	int err;
2626 
2627 	err = mcp251xfd_clks_and_vdd_enable(priv);
2628 	if (err)
2629 		return err;
2630 
2631 	pm_runtime_get_noresume(ndev->dev.parent);
2632 	err = pm_runtime_set_active(ndev->dev.parent);
2633 	if (err)
2634 		goto out_runtime_put_noidle;
2635 	pm_runtime_enable(ndev->dev.parent);
2636 
2637 	mcp251xfd_register_quirks(priv);
2638 
2639 	err = mcp251xfd_chip_softreset(priv);
2640 	if (err == -ENODEV)
2641 		goto out_runtime_disable;
2642 	if (err)
2643 		goto out_chip_set_mode_sleep;
2644 
2645 	err = mcp251xfd_register_chip_detect(priv);
2646 	if (err)
2647 		goto out_chip_set_mode_sleep;
2648 
2649 	err = mcp251xfd_register_check_rx_int(priv);
2650 	if (err)
2651 		goto out_chip_set_mode_sleep;
2652 
2653 	err = register_candev(ndev);
2654 	if (err)
2655 		goto out_chip_set_mode_sleep;
2656 
2657 	err = mcp251xfd_register_done(priv);
2658 	if (err)
2659 		goto out_unregister_candev;
2660 
2661 	/* Put controller into sleep mode and let pm_runtime_put()
2662 	 * disable the clocks and vdd. If CONFIG_PM is not enabled,
2663 	 * the clocks and vdd will stay powered.
2664 	 */
2665 	err = mcp251xfd_chip_set_mode(priv, MCP251XFD_REG_CON_MODE_SLEEP);
2666 	if (err)
2667 		goto out_unregister_candev;
2668 
2669 	pm_runtime_put(ndev->dev.parent);
2670 
2671 	return 0;
2672 
2673  out_unregister_candev:
2674 	unregister_candev(ndev);
2675  out_chip_set_mode_sleep:
2676 	mcp251xfd_chip_set_mode(priv, MCP251XFD_REG_CON_MODE_SLEEP);
2677  out_runtime_disable:
2678 	pm_runtime_disable(ndev->dev.parent);
2679  out_runtime_put_noidle:
2680 	pm_runtime_put_noidle(ndev->dev.parent);
2681 	mcp251xfd_clks_and_vdd_disable(priv);
2682 
2683 	return err;
2684 }
2685 
2686 static inline void mcp251xfd_unregister(struct mcp251xfd_priv *priv)
2687 {
2688 	struct net_device *ndev	= priv->ndev;
2689 
2690 	unregister_candev(ndev);
2691 
2692 	pm_runtime_get_sync(ndev->dev.parent);
2693 	pm_runtime_put_noidle(ndev->dev.parent);
2694 	mcp251xfd_clks_and_vdd_disable(priv);
2695 	pm_runtime_disable(ndev->dev.parent);
2696 }
2697 
2698 static const struct of_device_id mcp251xfd_of_match[] = {
2699 	{
2700 		.compatible = "microchip,mcp2517fd",
2701 		.data = &mcp251xfd_devtype_data_mcp2517fd,
2702 	}, {
2703 		.compatible = "microchip,mcp2518fd",
2704 		.data = &mcp251xfd_devtype_data_mcp2518fd,
2705 	}, {
2706 		.compatible = "microchip,mcp251xfd",
2707 		.data = &mcp251xfd_devtype_data_mcp251xfd,
2708 	}, {
2709 		/* sentinel */
2710 	},
2711 };
2712 MODULE_DEVICE_TABLE(of, mcp251xfd_of_match);
2713 
2714 static const struct spi_device_id mcp251xfd_id_table[] = {
2715 	{
2716 		.name = "mcp2517fd",
2717 		.driver_data = (kernel_ulong_t)&mcp251xfd_devtype_data_mcp2517fd,
2718 	}, {
2719 		.name = "mcp2518fd",
2720 		.driver_data = (kernel_ulong_t)&mcp251xfd_devtype_data_mcp2518fd,
2721 	}, {
2722 		.name = "mcp251xfd",
2723 		.driver_data = (kernel_ulong_t)&mcp251xfd_devtype_data_mcp251xfd,
2724 	}, {
2725 		/* sentinel */
2726 	},
2727 };
2728 MODULE_DEVICE_TABLE(spi, mcp251xfd_id_table);
2729 
2730 static int mcp251xfd_probe(struct spi_device *spi)
2731 {
2732 	const void *match;
2733 	struct net_device *ndev;
2734 	struct mcp251xfd_priv *priv;
2735 	struct gpio_desc *rx_int;
2736 	struct regulator *reg_vdd, *reg_xceiver;
2737 	struct clk *clk;
2738 	u32 freq;
2739 	int err;
2740 
2741 	rx_int = devm_gpiod_get_optional(&spi->dev, "microchip,rx-int",
2742 					 GPIOD_IN);
2743 	if (PTR_ERR(rx_int) == -EPROBE_DEFER)
2744 		return -EPROBE_DEFER;
2745 	else if (IS_ERR(rx_int))
2746 		return PTR_ERR(rx_int);
2747 
2748 	reg_vdd = devm_regulator_get_optional(&spi->dev, "vdd");
2749 	if (PTR_ERR(reg_vdd) == -EPROBE_DEFER)
2750 		return -EPROBE_DEFER;
2751 	else if (PTR_ERR(reg_vdd) == -ENODEV)
2752 		reg_vdd = NULL;
2753 	else if (IS_ERR(reg_vdd))
2754 		return PTR_ERR(reg_vdd);
2755 
2756 	reg_xceiver = devm_regulator_get_optional(&spi->dev, "xceiver");
2757 	if (PTR_ERR(reg_xceiver) == -EPROBE_DEFER)
2758 		return -EPROBE_DEFER;
2759 	else if (PTR_ERR(reg_xceiver) == -ENODEV)
2760 		reg_xceiver = NULL;
2761 	else if (IS_ERR(reg_xceiver))
2762 		return PTR_ERR(reg_xceiver);
2763 
2764 	clk = devm_clk_get(&spi->dev, NULL);
2765 	if (IS_ERR(clk)) {
2766 		dev_err(&spi->dev, "No Oscillator (clock) defined.\n");
2767 		return PTR_ERR(clk);
2768 	}
2769 	freq = clk_get_rate(clk);
2770 
2771 	/* Sanity check */
2772 	if (freq < MCP251XFD_SYSCLOCK_HZ_MIN ||
2773 	    freq > MCP251XFD_SYSCLOCK_HZ_MAX) {
2774 		dev_err(&spi->dev,
2775 			"Oscillator frequency (%u Hz) is too low or high.\n",
2776 			freq);
2777 		return -ERANGE;
2778 	}
2779 
2780 	if (freq <= MCP251XFD_SYSCLOCK_HZ_MAX / MCP251XFD_OSC_PLL_MULTIPLIER) {
2781 		dev_err(&spi->dev,
2782 			"Oscillator frequency (%u Hz) is too low and PLL is not supported.\n",
2783 			freq);
2784 		return -ERANGE;
2785 	}
2786 
2787 	ndev = alloc_candev(sizeof(struct mcp251xfd_priv),
2788 			    MCP251XFD_TX_OBJ_NUM_MAX);
2789 	if (!ndev)
2790 		return -ENOMEM;
2791 
2792 	SET_NETDEV_DEV(ndev, &spi->dev);
2793 
2794 	ndev->netdev_ops = &mcp251xfd_netdev_ops;
2795 	ndev->irq = spi->irq;
2796 	ndev->flags |= IFF_ECHO;
2797 
2798 	priv = netdev_priv(ndev);
2799 	spi_set_drvdata(spi, priv);
2800 	priv->can.clock.freq = freq;
2801 	priv->can.do_set_mode = mcp251xfd_set_mode;
2802 	priv->can.do_get_berr_counter = mcp251xfd_get_berr_counter;
2803 	priv->can.bittiming_const = &mcp251xfd_bittiming_const;
2804 	priv->can.data_bittiming_const = &mcp251xfd_data_bittiming_const;
2805 	priv->can.ctrlmode_supported = CAN_CTRLMODE_LISTENONLY |
2806 		CAN_CTRLMODE_BERR_REPORTING | CAN_CTRLMODE_FD |
2807 		CAN_CTRLMODE_FD_NON_ISO;
2808 	priv->ndev = ndev;
2809 	priv->spi = spi;
2810 	priv->rx_int = rx_int;
2811 	priv->clk = clk;
2812 	priv->reg_vdd = reg_vdd;
2813 	priv->reg_xceiver = reg_xceiver;
2814 
2815 	match = device_get_match_data(&spi->dev);
2816 	if (match)
2817 		priv->devtype_data = *(struct mcp251xfd_devtype_data *)match;
2818 	else
2819 		priv->devtype_data = *(struct mcp251xfd_devtype_data *)
2820 			spi_get_device_id(spi)->driver_data;
2821 
2822 	/* Errata Reference:
2823 	 * mcp2517fd: DS80000789B, mcp2518fd: DS80000792C 4.
2824 	 *
2825 	 * The SPI can write corrupted data to the RAM at fast SPI
2826 	 * speeds:
2827 	 *
2828 	 * Simultaneous activity on the CAN bus while writing data to
2829 	 * RAM via the SPI interface, with high SCK frequency, can
2830 	 * lead to corrupted data being written to RAM.
2831 	 *
2832 	 * Fix/Work Around:
2833 	 * Ensure that FSCK is less than or equal to 0.85 *
2834 	 * (FSYSCLK/2).
2835 	 *
2836 	 * Known good and bad combinations are:
2837 	 *
2838 	 * MCP	ext-clk	SoC			SPI			SPI-clk		max-clk	parent-clk	Status	config
2839 	 *
2840 	 * 2518	20 MHz	allwinner,sun8i-h3	allwinner,sun8i-h3-spi	 8333333 Hz	 83.33%	600000000 Hz	good	assigned-clocks = <&ccu CLK_SPIx>
2841 	 * 2518	20 MHz	allwinner,sun8i-h3	allwinner,sun8i-h3-spi	 9375000 Hz	 93.75%	600000000 Hz	bad	assigned-clocks = <&ccu CLK_SPIx>
2842 	 * 2518	40 MHz	allwinner,sun8i-h3	allwinner,sun8i-h3-spi	16666667 Hz	 83.33%	600000000 Hz	good	assigned-clocks = <&ccu CLK_SPIx>
2843 	 * 2518	40 MHz	allwinner,sun8i-h3	allwinner,sun8i-h3-spi	18750000 Hz	 93.75%	600000000 Hz	bad	assigned-clocks = <&ccu CLK_SPIx>
2844 	 * 2517	20 MHz	fsl,imx8mm		fsl,imx51-ecspi		 8333333 Hz	 83.33%	 16666667 Hz	good	assigned-clocks = <&clk IMX8MM_CLK_ECSPIx_ROOT>
2845 	 * 2517	20 MHz	fsl,imx8mm		fsl,imx51-ecspi		 9523809 Hz	 95.34%	 28571429 Hz	bad	assigned-clocks = <&clk IMX8MM_CLK_ECSPIx_ROOT>
2846 	 * 2517 40 MHz	atmel,sama5d27		atmel,at91rm9200-spi	16400000 Hz	 82.00%	 82000000 Hz	good	default
2847 	 * 2518 40 MHz	atmel,sama5d27		atmel,at91rm9200-spi	16400000 Hz	 82.00%	 82000000 Hz	good	default
2848 	 *
2849 	 */
2850 	priv->spi_max_speed_hz_orig = spi->max_speed_hz;
2851 	spi->max_speed_hz = min(spi->max_speed_hz, freq / 2 / 1000 * 850);
2852 	spi->bits_per_word = 8;
2853 	spi->rt = true;
2854 	err = spi_setup(spi);
2855 	if (err)
2856 		goto out_free_candev;
2857 
2858 	err = mcp251xfd_regmap_init(priv);
2859 	if (err)
2860 		goto out_free_candev;
2861 
2862 	err = can_rx_offload_add_manual(ndev, &priv->offload,
2863 					MCP251XFD_NAPI_WEIGHT);
2864 	if (err)
2865 		goto out_free_candev;
2866 
2867 	err = mcp251xfd_register(priv);
2868 	if (err)
2869 		goto out_free_candev;
2870 
2871 	return 0;
2872 
2873  out_free_candev:
2874 	spi->max_speed_hz = priv->spi_max_speed_hz_orig;
2875 
2876 	free_candev(ndev);
2877 
2878 	return err;
2879 }
2880 
2881 static int mcp251xfd_remove(struct spi_device *spi)
2882 {
2883 	struct mcp251xfd_priv *priv = spi_get_drvdata(spi);
2884 	struct net_device *ndev = priv->ndev;
2885 
2886 	can_rx_offload_del(&priv->offload);
2887 	mcp251xfd_unregister(priv);
2888 	spi->max_speed_hz = priv->spi_max_speed_hz_orig;
2889 	free_candev(ndev);
2890 
2891 	return 0;
2892 }
2893 
2894 static int __maybe_unused mcp251xfd_runtime_suspend(struct device *device)
2895 {
2896 	const struct mcp251xfd_priv *priv = dev_get_drvdata(device);
2897 
2898 	return mcp251xfd_clks_and_vdd_disable(priv);
2899 }
2900 
2901 static int __maybe_unused mcp251xfd_runtime_resume(struct device *device)
2902 {
2903 	const struct mcp251xfd_priv *priv = dev_get_drvdata(device);
2904 
2905 	return mcp251xfd_clks_and_vdd_enable(priv);
2906 }
2907 
2908 static const struct dev_pm_ops mcp251xfd_pm_ops = {
2909 	SET_RUNTIME_PM_OPS(mcp251xfd_runtime_suspend,
2910 			   mcp251xfd_runtime_resume, NULL)
2911 };
2912 
2913 static struct spi_driver mcp251xfd_driver = {
2914 	.driver = {
2915 		.name = DEVICE_NAME,
2916 		.pm = &mcp251xfd_pm_ops,
2917 		.of_match_table = mcp251xfd_of_match,
2918 	},
2919 	.probe = mcp251xfd_probe,
2920 	.remove = mcp251xfd_remove,
2921 	.id_table = mcp251xfd_id_table,
2922 };
2923 module_spi_driver(mcp251xfd_driver);
2924 
2925 MODULE_AUTHOR("Marc Kleine-Budde <mkl@pengutronix.de>");
2926 MODULE_DESCRIPTION("Microchip MCP251xFD Family CAN controller driver");
2927 MODULE_LICENSE("GPL v2");
2928