xref: /linux/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // mcp251xfd - Microchip MCP251xFD Family CAN controller driver
4 //
5 // Copyright (c) 2019, 2020, 2021, 2023 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/unaligned.h>
16 #include <linux/bitfield.h>
17 #include <linux/clk.h>
18 #include <linux/device.h>
19 #include <linux/mod_devicetable.h>
20 #include <linux/module.h>
21 #include <linux/pm_runtime.h>
22 #include <linux/property.h>
23 
24 #include "mcp251xfd.h"
25 
26 #define DEVICE_NAME "mcp251xfd"
27 
28 static const struct mcp251xfd_devtype_data mcp251xfd_devtype_data_mcp2517fd = {
29 	.quirks = MCP251XFD_QUIRK_MAB_NO_WARN | MCP251XFD_QUIRK_CRC_REG |
30 		MCP251XFD_QUIRK_CRC_RX | MCP251XFD_QUIRK_CRC_TX |
31 		MCP251XFD_QUIRK_ECC,
32 	.model = MCP251XFD_MODEL_MCP2517FD,
33 };
34 
35 static const struct mcp251xfd_devtype_data mcp251xfd_devtype_data_mcp2518fd = {
36 	.quirks = MCP251XFD_QUIRK_CRC_REG | MCP251XFD_QUIRK_CRC_RX |
37 		MCP251XFD_QUIRK_CRC_TX | MCP251XFD_QUIRK_ECC,
38 	.model = MCP251XFD_MODEL_MCP2518FD,
39 };
40 
41 static const struct mcp251xfd_devtype_data mcp251xfd_devtype_data_mcp251863 = {
42 	.quirks = MCP251XFD_QUIRK_CRC_REG | MCP251XFD_QUIRK_CRC_RX |
43 		MCP251XFD_QUIRK_CRC_TX | MCP251XFD_QUIRK_ECC,
44 	.model = MCP251XFD_MODEL_MCP251863,
45 };
46 
47 /* Autodetect model, start with CRC enabled. */
48 static const struct mcp251xfd_devtype_data mcp251xfd_devtype_data_mcp251xfd = {
49 	.quirks = MCP251XFD_QUIRK_CRC_REG | MCP251XFD_QUIRK_CRC_RX |
50 		MCP251XFD_QUIRK_CRC_TX | MCP251XFD_QUIRK_ECC,
51 	.model = MCP251XFD_MODEL_MCP251XFD,
52 };
53 
54 static const struct can_bittiming_const mcp251xfd_bittiming_const = {
55 	.name = DEVICE_NAME,
56 	.tseg1_min = 2,
57 	.tseg1_max = 256,
58 	.tseg2_min = 1,
59 	.tseg2_max = 128,
60 	.sjw_max = 128,
61 	.brp_min = 1,
62 	.brp_max = 256,
63 	.brp_inc = 1,
64 };
65 
66 static const struct can_bittiming_const mcp251xfd_data_bittiming_const = {
67 	.name = DEVICE_NAME,
68 	.tseg1_min = 1,
69 	.tseg1_max = 32,
70 	.tseg2_min = 1,
71 	.tseg2_max = 16,
72 	.sjw_max = 16,
73 	.brp_min = 1,
74 	.brp_max = 256,
75 	.brp_inc = 1,
76 };
77 
78 static const char *__mcp251xfd_get_model_str(enum mcp251xfd_model model)
79 {
80 	switch (model) {
81 	case MCP251XFD_MODEL_MCP2517FD:
82 		return "MCP2517FD";
83 	case MCP251XFD_MODEL_MCP2518FD:
84 		return "MCP2518FD";
85 	case MCP251XFD_MODEL_MCP251863:
86 		return "MCP251863";
87 	case MCP251XFD_MODEL_MCP251XFD:
88 		return "MCP251xFD";
89 	}
90 
91 	return "<unknown>";
92 }
93 
94 static inline const char *
95 mcp251xfd_get_model_str(const struct mcp251xfd_priv *priv)
96 {
97 	return __mcp251xfd_get_model_str(priv->devtype_data.model);
98 }
99 
100 static const char *mcp251xfd_get_mode_str(const u8 mode)
101 {
102 	switch (mode) {
103 	case MCP251XFD_REG_CON_MODE_MIXED:
104 		return "Mixed (CAN FD/CAN 2.0)";
105 	case MCP251XFD_REG_CON_MODE_SLEEP:
106 		return "Sleep";
107 	case MCP251XFD_REG_CON_MODE_INT_LOOPBACK:
108 		return "Internal Loopback";
109 	case MCP251XFD_REG_CON_MODE_LISTENONLY:
110 		return "Listen Only";
111 	case MCP251XFD_REG_CON_MODE_CONFIG:
112 		return "Configuration";
113 	case MCP251XFD_REG_CON_MODE_EXT_LOOPBACK:
114 		return "External Loopback";
115 	case MCP251XFD_REG_CON_MODE_CAN2_0:
116 		return "CAN 2.0";
117 	case MCP251XFD_REG_CON_MODE_RESTRICTED:
118 		return "Restricted Operation";
119 	}
120 
121 	return "<unknown>";
122 }
123 
124 static const char *
125 mcp251xfd_get_osc_str(const u32 osc, const u32 osc_reference)
126 {
127 	switch (~osc & osc_reference &
128 		(MCP251XFD_REG_OSC_OSCRDY | MCP251XFD_REG_OSC_PLLRDY)) {
129 	case MCP251XFD_REG_OSC_PLLRDY:
130 		return "PLL";
131 	case MCP251XFD_REG_OSC_OSCRDY:
132 		return "Oscillator";
133 	case MCP251XFD_REG_OSC_PLLRDY | MCP251XFD_REG_OSC_OSCRDY:
134 		return "Oscillator/PLL";
135 	}
136 
137 	return "<unknown>";
138 }
139 
140 static inline int mcp251xfd_vdd_enable(const struct mcp251xfd_priv *priv)
141 {
142 	if (!priv->reg_vdd)
143 		return 0;
144 
145 	return regulator_enable(priv->reg_vdd);
146 }
147 
148 static inline int mcp251xfd_vdd_disable(const struct mcp251xfd_priv *priv)
149 {
150 	if (!priv->reg_vdd)
151 		return 0;
152 
153 	return regulator_disable(priv->reg_vdd);
154 }
155 
156 static inline int
157 mcp251xfd_transceiver_enable(const struct mcp251xfd_priv *priv)
158 {
159 	if (!priv->reg_xceiver)
160 		return 0;
161 
162 	return regulator_enable(priv->reg_xceiver);
163 }
164 
165 static inline int
166 mcp251xfd_transceiver_disable(const struct mcp251xfd_priv *priv)
167 {
168 	if (!priv->reg_xceiver)
169 		return 0;
170 
171 	return regulator_disable(priv->reg_xceiver);
172 }
173 
174 static int mcp251xfd_clks_and_vdd_enable(const struct mcp251xfd_priv *priv)
175 {
176 	int err;
177 
178 	err = clk_prepare_enable(priv->clk);
179 	if (err)
180 		return err;
181 
182 	err = mcp251xfd_vdd_enable(priv);
183 	if (err)
184 		clk_disable_unprepare(priv->clk);
185 
186 	/* Wait for oscillator stabilisation time after power up */
187 	usleep_range(MCP251XFD_OSC_STAB_SLEEP_US,
188 		     2 * MCP251XFD_OSC_STAB_SLEEP_US);
189 
190 	return err;
191 }
192 
193 static int mcp251xfd_clks_and_vdd_disable(const struct mcp251xfd_priv *priv)
194 {
195 	int err;
196 
197 	err = mcp251xfd_vdd_disable(priv);
198 	if (err)
199 		return err;
200 
201 	clk_disable_unprepare(priv->clk);
202 
203 	return 0;
204 }
205 
206 static inline bool mcp251xfd_reg_invalid(u32 reg)
207 {
208 	return reg == 0x0 || reg == 0xffffffff;
209 }
210 
211 static inline int
212 mcp251xfd_chip_get_mode(const struct mcp251xfd_priv *priv, u8 *mode)
213 {
214 	u32 val;
215 	int err;
216 
217 	err = regmap_read(priv->map_reg, MCP251XFD_REG_CON, &val);
218 	if (err)
219 		return err;
220 
221 	*mode = FIELD_GET(MCP251XFD_REG_CON_OPMOD_MASK, val);
222 
223 	return 0;
224 }
225 
226 static int
227 __mcp251xfd_chip_set_mode(const struct mcp251xfd_priv *priv,
228 			  const u8 mode_req, bool nowait)
229 {
230 	const struct can_bittiming *bt = &priv->can.bittiming;
231 	unsigned long timeout_us = MCP251XFD_POLL_TIMEOUT_US;
232 	u32 con = 0, con_reqop, osc = 0;
233 	u8 mode;
234 	int err;
235 
236 	con_reqop = FIELD_PREP(MCP251XFD_REG_CON_REQOP_MASK, mode_req);
237 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_CON,
238 				 MCP251XFD_REG_CON_REQOP_MASK, con_reqop);
239 	if (err == -EBADMSG) {
240 		netdev_err(priv->ndev,
241 			   "Failed to set Requested Operation Mode.\n");
242 
243 		return -ENODEV;
244 	} else if (err) {
245 		return err;
246 	}
247 
248 	if (mode_req == MCP251XFD_REG_CON_MODE_SLEEP || nowait)
249 		return 0;
250 
251 	if (bt->bitrate)
252 		timeout_us = max_t(unsigned long, timeout_us,
253 				   MCP251XFD_FRAME_LEN_MAX_BITS * USEC_PER_SEC /
254 				   bt->bitrate);
255 
256 	err = regmap_read_poll_timeout(priv->map_reg, MCP251XFD_REG_CON, con,
257 				       !mcp251xfd_reg_invalid(con) &&
258 				       FIELD_GET(MCP251XFD_REG_CON_OPMOD_MASK,
259 						 con) == mode_req,
260 				       MCP251XFD_POLL_SLEEP_US, timeout_us);
261 	if (err != -ETIMEDOUT && err != -EBADMSG)
262 		return err;
263 
264 	/* Ignore return value.
265 	 * Print below error messages, even if this fails.
266 	 */
267 	regmap_read(priv->map_reg, MCP251XFD_REG_OSC, &osc);
268 
269 	if (mcp251xfd_reg_invalid(con)) {
270 		netdev_err(priv->ndev,
271 			   "Failed to read CAN Control Register (con=0x%08x, osc=0x%08x).\n",
272 			   con, osc);
273 
274 		return -ENODEV;
275 	}
276 
277 	mode = FIELD_GET(MCP251XFD_REG_CON_OPMOD_MASK, con);
278 	netdev_err(priv->ndev,
279 		   "Controller failed to enter mode %s Mode (%u) and stays in %s Mode (%u) (con=0x%08x, osc=0x%08x).\n",
280 		   mcp251xfd_get_mode_str(mode_req), mode_req,
281 		   mcp251xfd_get_mode_str(mode), mode,
282 		   con, osc);
283 
284 	return -ETIMEDOUT;
285 }
286 
287 static inline int
288 mcp251xfd_chip_set_mode(const struct mcp251xfd_priv *priv,
289 			const u8 mode_req)
290 {
291 	return __mcp251xfd_chip_set_mode(priv, mode_req, false);
292 }
293 
294 static inline int __maybe_unused
295 mcp251xfd_chip_set_mode_nowait(const struct mcp251xfd_priv *priv,
296 			       const u8 mode_req)
297 {
298 	return __mcp251xfd_chip_set_mode(priv, mode_req, true);
299 }
300 
301 static int
302 mcp251xfd_chip_wait_for_osc_ready(const struct mcp251xfd_priv *priv,
303 				  u32 osc_reference, u32 osc_mask)
304 {
305 	u32 osc;
306 	int err;
307 
308 	err = regmap_read_poll_timeout(priv->map_reg, MCP251XFD_REG_OSC, osc,
309 				       !mcp251xfd_reg_invalid(osc) &&
310 				       (osc & osc_mask) == osc_reference,
311 				       MCP251XFD_OSC_STAB_SLEEP_US,
312 				       MCP251XFD_OSC_STAB_TIMEOUT_US);
313 	if (err != -ETIMEDOUT)
314 		return err;
315 
316 	if (mcp251xfd_reg_invalid(osc)) {
317 		netdev_err(priv->ndev,
318 			   "Failed to read Oscillator Configuration Register (osc=0x%08x).\n",
319 			   osc);
320 		return -ENODEV;
321 	}
322 
323 	netdev_err(priv->ndev,
324 		   "Timeout waiting for %s ready (osc=0x%08x, osc_reference=0x%08x, osc_mask=0x%08x).\n",
325 		   mcp251xfd_get_osc_str(osc, osc_reference),
326 		   osc, osc_reference, osc_mask);
327 
328 	return -ETIMEDOUT;
329 }
330 
331 static int mcp251xfd_chip_wake(const struct mcp251xfd_priv *priv)
332 {
333 	u32 osc, osc_reference, osc_mask;
334 	int err;
335 
336 	/* For normal sleep on MCP2517FD and MCP2518FD, clearing
337 	 * "Oscillator Disable" will wake the chip. For low power mode
338 	 * on MCP2518FD, asserting the chip select will wake the
339 	 * chip. Writing to the Oscillator register will wake it in
340 	 * both cases.
341 	 */
342 	osc = FIELD_PREP(MCP251XFD_REG_OSC_CLKODIV_MASK,
343 			 MCP251XFD_REG_OSC_CLKODIV_10);
344 
345 	/* We cannot check for the PLL ready bit (either set or
346 	 * unset), as the PLL might be enabled. This can happen if the
347 	 * system reboots, while the mcp251xfd stays powered.
348 	 */
349 	osc_reference = MCP251XFD_REG_OSC_OSCRDY;
350 	osc_mask = MCP251XFD_REG_OSC_OSCRDY;
351 
352 	/* If the controller is in Sleep Mode the following write only
353 	 * removes the "Oscillator Disable" bit and powers it up. All
354 	 * other bits are unaffected.
355 	 */
356 	err = regmap_write(priv->map_reg, MCP251XFD_REG_OSC, osc);
357 	if (err)
358 		return err;
359 
360 	/* Sometimes the PLL is stuck enabled, the controller never
361 	 * sets the OSC Ready bit, and we get an -ETIMEDOUT. Our
362 	 * caller takes care of retry.
363 	 */
364 	return mcp251xfd_chip_wait_for_osc_ready(priv, osc_reference, osc_mask);
365 }
366 
367 static inline int mcp251xfd_chip_sleep(const struct mcp251xfd_priv *priv)
368 {
369 	if (priv->pll_enable) {
370 		u32 osc;
371 		int err;
372 
373 		/* Turn off PLL */
374 		osc = FIELD_PREP(MCP251XFD_REG_OSC_CLKODIV_MASK,
375 				 MCP251XFD_REG_OSC_CLKODIV_10);
376 		err = regmap_write(priv->map_reg, MCP251XFD_REG_OSC, osc);
377 		if (err)
378 			netdev_err(priv->ndev,
379 				   "Failed to disable PLL.\n");
380 
381 		priv->spi->max_speed_hz = priv->spi_max_speed_hz_slow;
382 	}
383 
384 	return mcp251xfd_chip_set_mode(priv, MCP251XFD_REG_CON_MODE_SLEEP);
385 }
386 
387 static int mcp251xfd_chip_softreset_do(const struct mcp251xfd_priv *priv)
388 {
389 	const __be16 cmd = mcp251xfd_cmd_reset();
390 	int err;
391 
392 	/* The Set Mode and SPI Reset command only works if the
393 	 * controller is not in Sleep Mode.
394 	 */
395 	err = mcp251xfd_chip_wake(priv);
396 	if (err)
397 		return err;
398 
399 	err = mcp251xfd_chip_set_mode(priv, MCP251XFD_REG_CON_MODE_CONFIG);
400 	if (err)
401 		return err;
402 
403 	/* spi_write_then_read() works with non DMA-safe buffers */
404 	return spi_write_then_read(priv->spi, &cmd, sizeof(cmd), NULL, 0);
405 }
406 
407 static int mcp251xfd_chip_softreset_check(const struct mcp251xfd_priv *priv)
408 {
409 	u32 osc_reference, osc_mask;
410 	u8 mode;
411 	int err;
412 
413 	/* Check for reset defaults of OSC reg.
414 	 * This will take care of stabilization period.
415 	 */
416 	osc_reference = MCP251XFD_REG_OSC_OSCRDY |
417 		FIELD_PREP(MCP251XFD_REG_OSC_CLKODIV_MASK,
418 			   MCP251XFD_REG_OSC_CLKODIV_10);
419 	osc_mask = osc_reference | MCP251XFD_REG_OSC_PLLRDY;
420 	err = mcp251xfd_chip_wait_for_osc_ready(priv, osc_reference, osc_mask);
421 	if (err)
422 		return err;
423 
424 	err = mcp251xfd_chip_get_mode(priv, &mode);
425 	if (err)
426 		return err;
427 
428 	if (mode != MCP251XFD_REG_CON_MODE_CONFIG) {
429 		netdev_info(priv->ndev,
430 			    "Controller not in Config Mode after reset, but in %s Mode (%u).\n",
431 			    mcp251xfd_get_mode_str(mode), mode);
432 		return -ETIMEDOUT;
433 	}
434 
435 	return 0;
436 }
437 
438 static int mcp251xfd_chip_softreset(const struct mcp251xfd_priv *priv)
439 {
440 	int err, i;
441 
442 	for (i = 0; i < MCP251XFD_SOFTRESET_RETRIES_MAX; i++) {
443 		if (i)
444 			netdev_info(priv->ndev,
445 				    "Retrying to reset controller.\n");
446 
447 		err = mcp251xfd_chip_softreset_do(priv);
448 		if (err == -ETIMEDOUT)
449 			continue;
450 		if (err)
451 			return err;
452 
453 		err = mcp251xfd_chip_softreset_check(priv);
454 		if (err == -ETIMEDOUT)
455 			continue;
456 		if (err)
457 			return err;
458 
459 		return 0;
460 	}
461 
462 	return err;
463 }
464 
465 static int mcp251xfd_chip_clock_init(const struct mcp251xfd_priv *priv)
466 {
467 	u32 osc, osc_reference, osc_mask;
468 	int err;
469 
470 	/* Activate Low Power Mode on Oscillator Disable. This only
471 	 * works on the MCP2518FD. The MCP2517FD will go into normal
472 	 * Sleep Mode instead.
473 	 */
474 	osc = MCP251XFD_REG_OSC_LPMEN |
475 		FIELD_PREP(MCP251XFD_REG_OSC_CLKODIV_MASK,
476 			   MCP251XFD_REG_OSC_CLKODIV_10);
477 	osc_reference = MCP251XFD_REG_OSC_OSCRDY;
478 	osc_mask = MCP251XFD_REG_OSC_OSCRDY | MCP251XFD_REG_OSC_PLLRDY;
479 
480 	if (priv->pll_enable) {
481 		osc |= MCP251XFD_REG_OSC_PLLEN;
482 		osc_reference |= MCP251XFD_REG_OSC_PLLRDY;
483 	}
484 
485 	err = regmap_write(priv->map_reg, MCP251XFD_REG_OSC, osc);
486 	if (err)
487 		return err;
488 
489 	err = mcp251xfd_chip_wait_for_osc_ready(priv, osc_reference, osc_mask);
490 	if (err)
491 		return err;
492 
493 	priv->spi->max_speed_hz = priv->spi_max_speed_hz_fast;
494 
495 	return 0;
496 }
497 
498 static int mcp251xfd_chip_timestamp_init(const struct mcp251xfd_priv *priv)
499 {
500 	/* Set Time Base Counter Prescaler to 1.
501 	 *
502 	 * This means an overflow of the 32 bit Time Base Counter
503 	 * register at 40 MHz every 107 seconds.
504 	 */
505 	return regmap_write(priv->map_reg, MCP251XFD_REG_TSCON,
506 			    MCP251XFD_REG_TSCON_TBCEN);
507 }
508 
509 static int mcp251xfd_set_bittiming(const struct mcp251xfd_priv *priv)
510 {
511 	const struct can_bittiming *bt = &priv->can.bittiming;
512 	const struct can_bittiming *dbt = &priv->can.data_bittiming;
513 	u32 val = 0;
514 	s8 tdco;
515 	int err;
516 
517 	/* CAN Control Register
518 	 *
519 	 * - no transmit bandwidth sharing
520 	 * - config mode
521 	 * - disable transmit queue
522 	 * - store in transmit FIFO event
523 	 * - transition to restricted operation mode on system error
524 	 * - ESI is transmitted recessive when ESI of message is high or
525 	 *   CAN controller error passive
526 	 * - restricted retransmission attempts,
527 	 *   use TQXCON_TXAT and FIFOCON_TXAT
528 	 * - wake-up filter bits T11FILTER
529 	 * - use CAN bus line filter for wakeup
530 	 * - protocol exception is treated as a form error
531 	 * - Do not compare data bytes
532 	 */
533 	val = FIELD_PREP(MCP251XFD_REG_CON_REQOP_MASK,
534 			 MCP251XFD_REG_CON_MODE_CONFIG) |
535 		MCP251XFD_REG_CON_STEF |
536 		MCP251XFD_REG_CON_ESIGM |
537 		MCP251XFD_REG_CON_RTXAT |
538 		FIELD_PREP(MCP251XFD_REG_CON_WFT_MASK,
539 			   MCP251XFD_REG_CON_WFT_T11FILTER) |
540 		MCP251XFD_REG_CON_WAKFIL |
541 		MCP251XFD_REG_CON_PXEDIS;
542 
543 	if (!(priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO))
544 		val |= MCP251XFD_REG_CON_ISOCRCEN;
545 
546 	err = regmap_write(priv->map_reg, MCP251XFD_REG_CON, val);
547 	if (err)
548 		return err;
549 
550 	/* Nominal Bit Time */
551 	val = FIELD_PREP(MCP251XFD_REG_NBTCFG_BRP_MASK, bt->brp - 1) |
552 		FIELD_PREP(MCP251XFD_REG_NBTCFG_TSEG1_MASK,
553 			   bt->prop_seg + bt->phase_seg1 - 1) |
554 		FIELD_PREP(MCP251XFD_REG_NBTCFG_TSEG2_MASK,
555 			   bt->phase_seg2 - 1) |
556 		FIELD_PREP(MCP251XFD_REG_NBTCFG_SJW_MASK, bt->sjw - 1);
557 
558 	err = regmap_write(priv->map_reg, MCP251XFD_REG_NBTCFG, val);
559 	if (err)
560 		return err;
561 
562 	if (!(priv->can.ctrlmode & CAN_CTRLMODE_FD))
563 		return 0;
564 
565 	/* Data Bit Time */
566 	val = FIELD_PREP(MCP251XFD_REG_DBTCFG_BRP_MASK, dbt->brp - 1) |
567 		FIELD_PREP(MCP251XFD_REG_DBTCFG_TSEG1_MASK,
568 			   dbt->prop_seg + dbt->phase_seg1 - 1) |
569 		FIELD_PREP(MCP251XFD_REG_DBTCFG_TSEG2_MASK,
570 			   dbt->phase_seg2 - 1) |
571 		FIELD_PREP(MCP251XFD_REG_DBTCFG_SJW_MASK, dbt->sjw - 1);
572 
573 	err = regmap_write(priv->map_reg, MCP251XFD_REG_DBTCFG, val);
574 	if (err)
575 		return err;
576 
577 	/* Transmitter Delay Compensation */
578 	tdco = clamp_t(int, dbt->brp * (dbt->prop_seg + dbt->phase_seg1),
579 		       -64, 63);
580 	val = FIELD_PREP(MCP251XFD_REG_TDC_TDCMOD_MASK,
581 			 MCP251XFD_REG_TDC_TDCMOD_AUTO) |
582 		FIELD_PREP(MCP251XFD_REG_TDC_TDCO_MASK, tdco);
583 
584 	return regmap_write(priv->map_reg, MCP251XFD_REG_TDC, val);
585 }
586 
587 static int mcp251xfd_chip_rx_int_enable(const struct mcp251xfd_priv *priv)
588 {
589 	u32 val;
590 
591 	if (!priv->rx_int)
592 		return 0;
593 
594 	/* Configure GPIOs:
595 	 * - PIN0: GPIO Input
596 	 * - PIN1: GPIO Input/RX Interrupt
597 	 *
598 	 * PIN1 must be Input, otherwise there is a glitch on the
599 	 * rx-INT line. It happens between setting the PIN as output
600 	 * (in the first byte of the SPI transfer) and configuring the
601 	 * PIN as interrupt (in the last byte of the SPI transfer).
602 	 */
603 	val = MCP251XFD_REG_IOCON_PM0 | MCP251XFD_REG_IOCON_TRIS1 |
604 		MCP251XFD_REG_IOCON_TRIS0;
605 	return regmap_write(priv->map_reg, MCP251XFD_REG_IOCON, val);
606 }
607 
608 static int mcp251xfd_chip_rx_int_disable(const struct mcp251xfd_priv *priv)
609 {
610 	u32 val;
611 
612 	if (!priv->rx_int)
613 		return 0;
614 
615 	/* Configure GPIOs:
616 	 * - PIN0: GPIO Input
617 	 * - PIN1: GPIO Input
618 	 */
619 	val = MCP251XFD_REG_IOCON_PM1 | MCP251XFD_REG_IOCON_PM0 |
620 		MCP251XFD_REG_IOCON_TRIS1 | MCP251XFD_REG_IOCON_TRIS0;
621 	return regmap_write(priv->map_reg, MCP251XFD_REG_IOCON, val);
622 }
623 
624 static int mcp251xfd_chip_ecc_init(struct mcp251xfd_priv *priv)
625 {
626 	struct mcp251xfd_ecc *ecc = &priv->ecc;
627 	void *ram;
628 	u32 val = 0;
629 	int err;
630 
631 	ecc->ecc_stat = 0;
632 
633 	if (priv->devtype_data.quirks & MCP251XFD_QUIRK_ECC)
634 		val = MCP251XFD_REG_ECCCON_ECCEN;
635 
636 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_ECCCON,
637 				 MCP251XFD_REG_ECCCON_ECCEN, val);
638 	if (err)
639 		return err;
640 
641 	ram = kzalloc(MCP251XFD_RAM_SIZE, GFP_KERNEL);
642 	if (!ram)
643 		return -ENOMEM;
644 
645 	err = regmap_raw_write(priv->map_reg, MCP251XFD_RAM_START, ram,
646 			       MCP251XFD_RAM_SIZE);
647 	kfree(ram);
648 
649 	return err;
650 }
651 
652 static u8 mcp251xfd_get_normal_mode(const struct mcp251xfd_priv *priv)
653 {
654 	u8 mode;
655 
656 	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
657 		mode = MCP251XFD_REG_CON_MODE_INT_LOOPBACK;
658 	else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
659 		mode = MCP251XFD_REG_CON_MODE_LISTENONLY;
660 	else if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
661 		mode = MCP251XFD_REG_CON_MODE_MIXED;
662 	else
663 		mode = MCP251XFD_REG_CON_MODE_CAN2_0;
664 
665 	return mode;
666 }
667 
668 static int
669 __mcp251xfd_chip_set_normal_mode(const struct mcp251xfd_priv *priv,
670 				 bool nowait)
671 {
672 	u8 mode;
673 
674 	mode = mcp251xfd_get_normal_mode(priv);
675 
676 	return __mcp251xfd_chip_set_mode(priv, mode, nowait);
677 }
678 
679 static inline int
680 mcp251xfd_chip_set_normal_mode(const struct mcp251xfd_priv *priv)
681 {
682 	return __mcp251xfd_chip_set_normal_mode(priv, false);
683 }
684 
685 static inline int
686 mcp251xfd_chip_set_normal_mode_nowait(const struct mcp251xfd_priv *priv)
687 {
688 	return __mcp251xfd_chip_set_normal_mode(priv, true);
689 }
690 
691 static int mcp251xfd_chip_interrupts_enable(const struct mcp251xfd_priv *priv)
692 {
693 	u32 val;
694 	int err;
695 
696 	val = MCP251XFD_REG_CRC_FERRIE | MCP251XFD_REG_CRC_CRCERRIE;
697 	err = regmap_write(priv->map_reg, MCP251XFD_REG_CRC, val);
698 	if (err)
699 		return err;
700 
701 	val = MCP251XFD_REG_ECCCON_DEDIE | MCP251XFD_REG_ECCCON_SECIE;
702 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_ECCCON, val, val);
703 	if (err)
704 		return err;
705 
706 	val = MCP251XFD_REG_INT_CERRIE |
707 		MCP251XFD_REG_INT_SERRIE |
708 		MCP251XFD_REG_INT_RXOVIE |
709 		MCP251XFD_REG_INT_TXATIE |
710 		MCP251XFD_REG_INT_SPICRCIE |
711 		MCP251XFD_REG_INT_ECCIE |
712 		MCP251XFD_REG_INT_TEFIE |
713 		MCP251XFD_REG_INT_MODIE |
714 		MCP251XFD_REG_INT_RXIE;
715 
716 	if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
717 		val |= MCP251XFD_REG_INT_IVMIE;
718 
719 	return regmap_write(priv->map_reg, MCP251XFD_REG_INT, val);
720 }
721 
722 static int mcp251xfd_chip_interrupts_disable(const struct mcp251xfd_priv *priv)
723 {
724 	int err;
725 	u32 mask;
726 
727 	err = regmap_write(priv->map_reg, MCP251XFD_REG_INT, 0);
728 	if (err)
729 		return err;
730 
731 	mask = MCP251XFD_REG_ECCCON_DEDIE | MCP251XFD_REG_ECCCON_SECIE;
732 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_ECCCON,
733 				 mask, 0x0);
734 	if (err)
735 		return err;
736 
737 	return regmap_write(priv->map_reg, MCP251XFD_REG_CRC, 0);
738 }
739 
740 static void mcp251xfd_chip_stop(struct mcp251xfd_priv *priv,
741 				const enum can_state state)
742 {
743 	priv->can.state = state;
744 
745 	mcp251xfd_chip_interrupts_disable(priv);
746 	mcp251xfd_chip_rx_int_disable(priv);
747 	mcp251xfd_timestamp_stop(priv);
748 	mcp251xfd_chip_sleep(priv);
749 }
750 
751 static int mcp251xfd_chip_start(struct mcp251xfd_priv *priv)
752 {
753 	int err;
754 
755 	err = mcp251xfd_chip_softreset(priv);
756 	if (err)
757 		goto out_chip_stop;
758 
759 	err = mcp251xfd_chip_clock_init(priv);
760 	if (err)
761 		goto out_chip_stop;
762 
763 	err = mcp251xfd_chip_timestamp_init(priv);
764 	if (err)
765 		goto out_chip_stop;
766 
767 	mcp251xfd_timestamp_start(priv);
768 
769 	err = mcp251xfd_set_bittiming(priv);
770 	if (err)
771 		goto out_chip_stop;
772 
773 	err = mcp251xfd_chip_rx_int_enable(priv);
774 	if (err)
775 		goto out_chip_stop;
776 
777 	err = mcp251xfd_chip_ecc_init(priv);
778 	if (err)
779 		goto out_chip_stop;
780 
781 	err = mcp251xfd_ring_init(priv);
782 	if (err)
783 		goto out_chip_stop;
784 
785 	err = mcp251xfd_chip_fifo_init(priv);
786 	if (err)
787 		goto out_chip_stop;
788 
789 	priv->can.state = CAN_STATE_ERROR_ACTIVE;
790 
791 	err = mcp251xfd_chip_set_normal_mode(priv);
792 	if (err)
793 		goto out_chip_stop;
794 
795 	return 0;
796 
797 out_chip_stop:
798 	mcp251xfd_dump(priv);
799 	mcp251xfd_chip_stop(priv, CAN_STATE_STOPPED);
800 
801 	return err;
802 }
803 
804 static int mcp251xfd_set_mode(struct net_device *ndev, enum can_mode mode)
805 {
806 	struct mcp251xfd_priv *priv = netdev_priv(ndev);
807 	int err;
808 
809 	switch (mode) {
810 	case CAN_MODE_START:
811 		err = mcp251xfd_chip_start(priv);
812 		if (err)
813 			return err;
814 
815 		err = mcp251xfd_chip_interrupts_enable(priv);
816 		if (err) {
817 			mcp251xfd_chip_stop(priv, CAN_STATE_STOPPED);
818 			return err;
819 		}
820 
821 		netif_wake_queue(ndev);
822 		break;
823 
824 	default:
825 		return -EOPNOTSUPP;
826 	}
827 
828 	return 0;
829 }
830 
831 static int __mcp251xfd_get_berr_counter(const struct net_device *ndev,
832 					struct can_berr_counter *bec)
833 {
834 	const struct mcp251xfd_priv *priv = netdev_priv(ndev);
835 	u32 trec;
836 	int err;
837 
838 	err = regmap_read(priv->map_reg, MCP251XFD_REG_TREC, &trec);
839 	if (err)
840 		return err;
841 
842 	if (trec & MCP251XFD_REG_TREC_TXBO)
843 		bec->txerr = CAN_BUS_OFF_THRESHOLD;
844 	else
845 		bec->txerr = FIELD_GET(MCP251XFD_REG_TREC_TEC_MASK, trec);
846 	bec->rxerr = FIELD_GET(MCP251XFD_REG_TREC_REC_MASK, trec);
847 
848 	return 0;
849 }
850 
851 static int mcp251xfd_get_berr_counter(const struct net_device *ndev,
852 				      struct can_berr_counter *bec)
853 {
854 	const struct mcp251xfd_priv *priv = netdev_priv(ndev);
855 
856 	/* Avoid waking up the controller if the interface is down */
857 	if (!(ndev->flags & IFF_UP))
858 		return 0;
859 
860 	/* The controller is powered down during Bus Off, use saved
861 	 * bec values.
862 	 */
863 	if (priv->can.state == CAN_STATE_BUS_OFF) {
864 		*bec = priv->bec;
865 		return 0;
866 	}
867 
868 	return __mcp251xfd_get_berr_counter(ndev, bec);
869 }
870 
871 static struct sk_buff *
872 mcp251xfd_alloc_can_err_skb(struct mcp251xfd_priv *priv,
873 			    struct can_frame **cf, u32 *ts_raw)
874 {
875 	struct sk_buff *skb;
876 	int err;
877 
878 	err = mcp251xfd_get_timestamp_raw(priv, ts_raw);
879 	if (err)
880 		return NULL;
881 
882 	skb = alloc_can_err_skb(priv->ndev, cf);
883 	if (skb)
884 		mcp251xfd_skb_set_timestamp_raw(priv, skb, *ts_raw);
885 
886 	return skb;
887 }
888 
889 static int mcp251xfd_handle_rxovif(struct mcp251xfd_priv *priv)
890 {
891 	struct net_device_stats *stats = &priv->ndev->stats;
892 	struct mcp251xfd_rx_ring *ring;
893 	struct sk_buff *skb;
894 	struct can_frame *cf;
895 	u32 ts_raw, rxovif;
896 	int err, i;
897 
898 	stats->rx_over_errors++;
899 	stats->rx_errors++;
900 
901 	err = regmap_read(priv->map_reg, MCP251XFD_REG_RXOVIF, &rxovif);
902 	if (err)
903 		return err;
904 
905 	mcp251xfd_for_each_rx_ring(priv, ring, i) {
906 		if (!(rxovif & BIT(ring->fifo_nr)))
907 			continue;
908 
909 		/* If SERRIF is active, there was a RX MAB overflow. */
910 		if (priv->regs_status.intf & MCP251XFD_REG_INT_SERRIF) {
911 			if (net_ratelimit())
912 				netdev_dbg(priv->ndev,
913 					   "RX-%d: MAB overflow detected.\n",
914 					   ring->nr);
915 		} else {
916 			if (net_ratelimit())
917 				netdev_dbg(priv->ndev,
918 					   "RX-%d: FIFO overflow.\n",
919 					   ring->nr);
920 		}
921 
922 		err = regmap_update_bits(priv->map_reg,
923 					 MCP251XFD_REG_FIFOSTA(ring->fifo_nr),
924 					 MCP251XFD_REG_FIFOSTA_RXOVIF,
925 					 0x0);
926 		if (err)
927 			return err;
928 	}
929 
930 	skb = mcp251xfd_alloc_can_err_skb(priv, &cf, &ts_raw);
931 	if (!skb)
932 		return 0;
933 
934 	cf->can_id |= CAN_ERR_CRTL;
935 	cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
936 
937 	err = can_rx_offload_queue_timestamp(&priv->offload, skb, ts_raw);
938 	if (err)
939 		stats->rx_fifo_errors++;
940 
941 	return 0;
942 }
943 
944 static int mcp251xfd_handle_txatif(struct mcp251xfd_priv *priv)
945 {
946 	netdev_info(priv->ndev, "%s\n", __func__);
947 
948 	return 0;
949 }
950 
951 static int mcp251xfd_handle_ivmif(struct mcp251xfd_priv *priv)
952 {
953 	struct net_device_stats *stats = &priv->ndev->stats;
954 	u32 bdiag1, ts_raw;
955 	struct sk_buff *skb;
956 	struct can_frame *cf = NULL;
957 	int err;
958 
959 	err = mcp251xfd_get_timestamp_raw(priv, &ts_raw);
960 	if (err)
961 		return err;
962 
963 	err = regmap_read(priv->map_reg, MCP251XFD_REG_BDIAG1, &bdiag1);
964 	if (err)
965 		return err;
966 
967 	/* Write 0s to clear error bits, don't write 1s to non active
968 	 * bits, as they will be set.
969 	 */
970 	err = regmap_write(priv->map_reg, MCP251XFD_REG_BDIAG1, 0x0);
971 	if (err)
972 		return err;
973 
974 	priv->can.can_stats.bus_error++;
975 
976 	skb = alloc_can_err_skb(priv->ndev, &cf);
977 	if (cf)
978 		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
979 
980 	/* Controller misconfiguration */
981 	if (WARN_ON(bdiag1 & MCP251XFD_REG_BDIAG1_DLCMM))
982 		netdev_err(priv->ndev,
983 			   "recv'd DLC is larger than PLSIZE of FIFO element.");
984 
985 	/* RX errors */
986 	if (bdiag1 & (MCP251XFD_REG_BDIAG1_DCRCERR |
987 		      MCP251XFD_REG_BDIAG1_NCRCERR)) {
988 		netdev_dbg(priv->ndev, "CRC error\n");
989 
990 		stats->rx_errors++;
991 		if (cf)
992 			cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
993 	}
994 	if (bdiag1 & (MCP251XFD_REG_BDIAG1_DSTUFERR |
995 		      MCP251XFD_REG_BDIAG1_NSTUFERR)) {
996 		netdev_dbg(priv->ndev, "Stuff error\n");
997 
998 		stats->rx_errors++;
999 		if (cf)
1000 			cf->data[2] |= CAN_ERR_PROT_STUFF;
1001 	}
1002 	if (bdiag1 & (MCP251XFD_REG_BDIAG1_DFORMERR |
1003 		      MCP251XFD_REG_BDIAG1_NFORMERR)) {
1004 		netdev_dbg(priv->ndev, "Format error\n");
1005 
1006 		stats->rx_errors++;
1007 		if (cf)
1008 			cf->data[2] |= CAN_ERR_PROT_FORM;
1009 	}
1010 
1011 	/* TX errors */
1012 	if (bdiag1 & MCP251XFD_REG_BDIAG1_NACKERR) {
1013 		netdev_dbg(priv->ndev, "NACK error\n");
1014 
1015 		stats->tx_errors++;
1016 		if (cf) {
1017 			cf->can_id |= CAN_ERR_ACK;
1018 			cf->data[2] |= CAN_ERR_PROT_TX;
1019 		}
1020 	}
1021 	if (bdiag1 & (MCP251XFD_REG_BDIAG1_DBIT1ERR |
1022 		      MCP251XFD_REG_BDIAG1_NBIT1ERR)) {
1023 		netdev_dbg(priv->ndev, "Bit1 error\n");
1024 
1025 		stats->tx_errors++;
1026 		if (cf)
1027 			cf->data[2] |= CAN_ERR_PROT_TX | CAN_ERR_PROT_BIT1;
1028 	}
1029 	if (bdiag1 & (MCP251XFD_REG_BDIAG1_DBIT0ERR |
1030 		      MCP251XFD_REG_BDIAG1_NBIT0ERR)) {
1031 		netdev_dbg(priv->ndev, "Bit0 error\n");
1032 
1033 		stats->tx_errors++;
1034 		if (cf)
1035 			cf->data[2] |= CAN_ERR_PROT_TX | CAN_ERR_PROT_BIT0;
1036 	}
1037 
1038 	if (!cf)
1039 		return 0;
1040 
1041 	mcp251xfd_skb_set_timestamp_raw(priv, skb, ts_raw);
1042 	err = can_rx_offload_queue_timestamp(&priv->offload, skb, ts_raw);
1043 	if (err)
1044 		stats->rx_fifo_errors++;
1045 
1046 	return 0;
1047 }
1048 
1049 static int mcp251xfd_handle_cerrif(struct mcp251xfd_priv *priv)
1050 {
1051 	struct net_device_stats *stats = &priv->ndev->stats;
1052 	struct sk_buff *skb;
1053 	struct can_frame *cf = NULL;
1054 	enum can_state new_state, rx_state, tx_state;
1055 	u32 trec, ts_raw;
1056 	int err;
1057 
1058 	err = regmap_read(priv->map_reg, MCP251XFD_REG_TREC, &trec);
1059 	if (err)
1060 		return err;
1061 
1062 	if (trec & MCP251XFD_REG_TREC_TXBO)
1063 		tx_state = CAN_STATE_BUS_OFF;
1064 	else if (trec & MCP251XFD_REG_TREC_TXBP)
1065 		tx_state = CAN_STATE_ERROR_PASSIVE;
1066 	else if (trec & MCP251XFD_REG_TREC_TXWARN)
1067 		tx_state = CAN_STATE_ERROR_WARNING;
1068 	else
1069 		tx_state = CAN_STATE_ERROR_ACTIVE;
1070 
1071 	if (trec & MCP251XFD_REG_TREC_RXBP)
1072 		rx_state = CAN_STATE_ERROR_PASSIVE;
1073 	else if (trec & MCP251XFD_REG_TREC_RXWARN)
1074 		rx_state = CAN_STATE_ERROR_WARNING;
1075 	else
1076 		rx_state = CAN_STATE_ERROR_ACTIVE;
1077 
1078 	new_state = max(tx_state, rx_state);
1079 	if (new_state == priv->can.state)
1080 		return 0;
1081 
1082 	/* The skb allocation might fail, but can_change_state()
1083 	 * handles cf == NULL.
1084 	 */
1085 	skb = mcp251xfd_alloc_can_err_skb(priv, &cf, &ts_raw);
1086 	can_change_state(priv->ndev, cf, tx_state, rx_state);
1087 
1088 	if (new_state == CAN_STATE_BUS_OFF) {
1089 		/* As we're going to switch off the chip now, let's
1090 		 * save the error counters and return them to
1091 		 * userspace, if do_get_berr_counter() is called while
1092 		 * the chip is in Bus Off.
1093 		 */
1094 		err = __mcp251xfd_get_berr_counter(priv->ndev, &priv->bec);
1095 		if (err)
1096 			return err;
1097 
1098 		mcp251xfd_chip_stop(priv, CAN_STATE_BUS_OFF);
1099 		can_bus_off(priv->ndev);
1100 	}
1101 
1102 	if (!skb)
1103 		return 0;
1104 
1105 	if (new_state != CAN_STATE_BUS_OFF) {
1106 		struct can_berr_counter bec;
1107 
1108 		err = mcp251xfd_get_berr_counter(priv->ndev, &bec);
1109 		if (err)
1110 			return err;
1111 		cf->can_id |= CAN_ERR_CNT;
1112 		cf->data[6] = bec.txerr;
1113 		cf->data[7] = bec.rxerr;
1114 	}
1115 
1116 	err = can_rx_offload_queue_timestamp(&priv->offload, skb, ts_raw);
1117 	if (err)
1118 		stats->rx_fifo_errors++;
1119 
1120 	return 0;
1121 }
1122 
1123 static int
1124 mcp251xfd_handle_modif(const struct mcp251xfd_priv *priv, bool *set_normal_mode)
1125 {
1126 	const u8 mode_reference = mcp251xfd_get_normal_mode(priv);
1127 	u8 mode;
1128 	int err;
1129 
1130 	err = mcp251xfd_chip_get_mode(priv, &mode);
1131 	if (err)
1132 		return err;
1133 
1134 	if (mode == mode_reference) {
1135 		netdev_dbg(priv->ndev,
1136 			   "Controller changed into %s Mode (%u).\n",
1137 			   mcp251xfd_get_mode_str(mode), mode);
1138 		return 0;
1139 	}
1140 
1141 	/* According to MCP2517FD errata DS80000792C 1., during a TX
1142 	 * MAB underflow, the controller will transition to Restricted
1143 	 * Operation Mode or Listen Only Mode (depending on SERR2LOM).
1144 	 *
1145 	 * However this is not always the case. If SERR2LOM is
1146 	 * configured for Restricted Operation Mode (SERR2LOM not set)
1147 	 * the MCP2517FD will sometimes transition to Listen Only Mode
1148 	 * first. When polling this bit we see that it will transition
1149 	 * to Restricted Operation Mode shortly after.
1150 	 */
1151 	if ((priv->devtype_data.quirks & MCP251XFD_QUIRK_MAB_NO_WARN) &&
1152 	    (mode == MCP251XFD_REG_CON_MODE_RESTRICTED ||
1153 	     mode == MCP251XFD_REG_CON_MODE_LISTENONLY))
1154 		netdev_dbg(priv->ndev,
1155 			   "Controller changed into %s Mode (%u).\n",
1156 			   mcp251xfd_get_mode_str(mode), mode);
1157 	else
1158 		netdev_err(priv->ndev,
1159 			   "Controller changed into %s Mode (%u).\n",
1160 			   mcp251xfd_get_mode_str(mode), mode);
1161 
1162 	/* After the application requests Normal mode, the controller
1163 	 * will automatically attempt to retransmit the message that
1164 	 * caused the TX MAB underflow.
1165 	 *
1166 	 * However, if there is an ECC error in the TX-RAM, we first
1167 	 * have to reload the tx-object before requesting Normal
1168 	 * mode. This is done later in mcp251xfd_handle_eccif().
1169 	 */
1170 	if (priv->regs_status.intf & MCP251XFD_REG_INT_ECCIF) {
1171 		*set_normal_mode = true;
1172 		return 0;
1173 	}
1174 
1175 	return mcp251xfd_chip_set_normal_mode_nowait(priv);
1176 }
1177 
1178 static int mcp251xfd_handle_serrif(struct mcp251xfd_priv *priv)
1179 {
1180 	struct mcp251xfd_ecc *ecc = &priv->ecc;
1181 	struct net_device_stats *stats = &priv->ndev->stats;
1182 	bool handled = false;
1183 
1184 	/* TX MAB underflow
1185 	 *
1186 	 * According to MCP2517FD Errata DS80000792C 1. a TX MAB
1187 	 * underflow is indicated by SERRIF and MODIF.
1188 	 *
1189 	 * In addition to the effects mentioned in the Errata, there
1190 	 * are Bus Errors due to the aborted CAN frame, so a IVMIF
1191 	 * will be seen as well.
1192 	 *
1193 	 * Sometimes there is an ECC error in the TX-RAM, which leads
1194 	 * to a TX MAB underflow.
1195 	 *
1196 	 * However, probably due to a race condition, there is no
1197 	 * associated MODIF pending.
1198 	 *
1199 	 * Further, there are situations, where the SERRIF is caused
1200 	 * by an ECC error in the TX-RAM, but not even the ECCIF is
1201 	 * set. This only seems to happen _after_ the first occurrence
1202 	 * of a ECCIF (which is tracked in ecc->cnt).
1203 	 *
1204 	 * Treat all as a known system errors..
1205 	 */
1206 	if ((priv->regs_status.intf & MCP251XFD_REG_INT_MODIF &&
1207 	     priv->regs_status.intf & MCP251XFD_REG_INT_IVMIF) ||
1208 	    priv->regs_status.intf & MCP251XFD_REG_INT_ECCIF ||
1209 	    ecc->cnt) {
1210 		const char *msg;
1211 
1212 		if (priv->regs_status.intf & MCP251XFD_REG_INT_ECCIF ||
1213 		    ecc->cnt)
1214 			msg = "TX MAB underflow due to ECC error detected.";
1215 		else
1216 			msg = "TX MAB underflow detected.";
1217 
1218 		if (priv->devtype_data.quirks & MCP251XFD_QUIRK_MAB_NO_WARN)
1219 			netdev_dbg(priv->ndev, "%s\n", msg);
1220 		else
1221 			netdev_info(priv->ndev, "%s\n", msg);
1222 
1223 		stats->tx_aborted_errors++;
1224 		stats->tx_errors++;
1225 		handled = true;
1226 	}
1227 
1228 	/* RX MAB overflow
1229 	 *
1230 	 * According to MCP2517FD Errata DS80000792C 1. a RX MAB
1231 	 * overflow is indicated by SERRIF.
1232 	 *
1233 	 * In addition to the effects mentioned in the Errata, (most
1234 	 * of the times) a RXOVIF is raised, if the FIFO that is being
1235 	 * received into has the RXOVIE activated (and we have enabled
1236 	 * RXOVIE on all FIFOs).
1237 	 *
1238 	 * Sometimes there is no RXOVIF just a RXIF is pending.
1239 	 *
1240 	 * Treat all as a known system errors..
1241 	 */
1242 	if (priv->regs_status.intf & MCP251XFD_REG_INT_RXOVIF ||
1243 	    priv->regs_status.intf & MCP251XFD_REG_INT_RXIF) {
1244 		stats->rx_dropped++;
1245 		handled = true;
1246 	}
1247 
1248 	if (!handled)
1249 		netdev_err(priv->ndev,
1250 			   "Unhandled System Error Interrupt (intf=0x%08x)!\n",
1251 			   priv->regs_status.intf);
1252 
1253 	return 0;
1254 }
1255 
1256 static int
1257 mcp251xfd_handle_eccif_recover(struct mcp251xfd_priv *priv, u8 nr)
1258 {
1259 	struct mcp251xfd_tx_ring *tx_ring = priv->tx;
1260 	struct mcp251xfd_ecc *ecc = &priv->ecc;
1261 	struct mcp251xfd_tx_obj *tx_obj;
1262 	u8 chip_tx_tail, tx_tail, offset;
1263 	u16 addr;
1264 	int err;
1265 
1266 	addr = FIELD_GET(MCP251XFD_REG_ECCSTAT_ERRADDR_MASK, ecc->ecc_stat);
1267 
1268 	err = mcp251xfd_tx_tail_get_from_chip(priv, &chip_tx_tail);
1269 	if (err)
1270 		return err;
1271 
1272 	tx_tail = mcp251xfd_get_tx_tail(tx_ring);
1273 	offset = (nr - chip_tx_tail) & (tx_ring->obj_num - 1);
1274 
1275 	/* Bail out if one of the following is met:
1276 	 * - tx_tail information is inconsistent
1277 	 * - for mcp2517fd: offset not 0
1278 	 * - for mcp2518fd: offset not 0 or 1
1279 	 */
1280 	if (chip_tx_tail != tx_tail ||
1281 	    !(offset == 0 || (offset == 1 && (mcp251xfd_is_2518FD(priv) ||
1282 					      mcp251xfd_is_251863(priv))))) {
1283 		netdev_err(priv->ndev,
1284 			   "ECC Error information inconsistent (addr=0x%04x, nr=%d, tx_tail=0x%08x(%d), chip_tx_tail=%d, offset=%d).\n",
1285 			   addr, nr, tx_ring->tail, tx_tail, chip_tx_tail,
1286 			   offset);
1287 		return -EINVAL;
1288 	}
1289 
1290 	netdev_info(priv->ndev,
1291 		    "Recovering %s ECC Error at address 0x%04x (in TX-RAM, tx_obj=%d, tx_tail=0x%08x(%d), offset=%d).\n",
1292 		    ecc->ecc_stat & MCP251XFD_REG_ECCSTAT_SECIF ?
1293 		    "Single" : "Double",
1294 		    addr, nr, tx_ring->tail, tx_tail, offset);
1295 
1296 	/* reload tx_obj into controller RAM ... */
1297 	tx_obj = &tx_ring->obj[nr];
1298 	err = spi_sync_transfer(priv->spi, tx_obj->xfer, 1);
1299 	if (err)
1300 		return err;
1301 
1302 	/* ... and trigger retransmit */
1303 	return mcp251xfd_chip_set_normal_mode(priv);
1304 }
1305 
1306 static int
1307 mcp251xfd_handle_eccif(struct mcp251xfd_priv *priv, bool set_normal_mode)
1308 {
1309 	struct mcp251xfd_ecc *ecc = &priv->ecc;
1310 	const char *msg;
1311 	bool in_tx_ram;
1312 	u32 ecc_stat;
1313 	u16 addr;
1314 	u8 nr;
1315 	int err;
1316 
1317 	err = regmap_read(priv->map_reg, MCP251XFD_REG_ECCSTAT, &ecc_stat);
1318 	if (err)
1319 		return err;
1320 
1321 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_ECCSTAT,
1322 				 MCP251XFD_REG_ECCSTAT_IF_MASK, ~ecc_stat);
1323 	if (err)
1324 		return err;
1325 
1326 	/* Check if ECC error occurred in TX-RAM */
1327 	addr = FIELD_GET(MCP251XFD_REG_ECCSTAT_ERRADDR_MASK, ecc_stat);
1328 	err = mcp251xfd_get_tx_nr_by_addr(priv->tx, &nr, addr);
1329 	if (!err)
1330 		in_tx_ram = true;
1331 	else if (err == -ENOENT)
1332 		in_tx_ram = false;
1333 	else
1334 		return err;
1335 
1336 	/* Errata Reference:
1337 	 * mcp2517fd: DS80000789C 3., mcp2518fd: DS80000792E 2.,
1338 	 * mcp251863: DS80000984A 2.
1339 	 *
1340 	 * ECC single error correction does not work in all cases:
1341 	 *
1342 	 * Fix/Work Around:
1343 	 * Enable single error correction and double error detection
1344 	 * interrupts by setting SECIE and DEDIE. Handle SECIF as a
1345 	 * detection interrupt and do not rely on the error
1346 	 * correction. Instead, handle both interrupts as a
1347 	 * notification that the RAM word at ERRADDR was corrupted.
1348 	 */
1349 	if (ecc_stat & MCP251XFD_REG_ECCSTAT_SECIF)
1350 		msg = "Single ECC Error detected at address";
1351 	else if (ecc_stat & MCP251XFD_REG_ECCSTAT_DEDIF)
1352 		msg = "Double ECC Error detected at address";
1353 	else
1354 		return -EINVAL;
1355 
1356 	if (!in_tx_ram) {
1357 		ecc->ecc_stat = 0;
1358 
1359 		netdev_notice(priv->ndev, "%s 0x%04x.\n", msg, addr);
1360 	} else {
1361 		/* Re-occurring error? */
1362 		if (ecc->ecc_stat == ecc_stat) {
1363 			ecc->cnt++;
1364 		} else {
1365 			ecc->ecc_stat = ecc_stat;
1366 			ecc->cnt = 1;
1367 		}
1368 
1369 		netdev_info(priv->ndev,
1370 			    "%s 0x%04x (in TX-RAM, tx_obj=%d), occurred %d time%s.\n",
1371 			    msg, addr, nr, ecc->cnt, ecc->cnt > 1 ? "s" : "");
1372 
1373 		if (ecc->cnt >= MCP251XFD_ECC_CNT_MAX)
1374 			return mcp251xfd_handle_eccif_recover(priv, nr);
1375 	}
1376 
1377 	if (set_normal_mode)
1378 		return mcp251xfd_chip_set_normal_mode_nowait(priv);
1379 
1380 	return 0;
1381 }
1382 
1383 static int mcp251xfd_handle_spicrcif(struct mcp251xfd_priv *priv)
1384 {
1385 	int err;
1386 	u32 crc;
1387 
1388 	err = regmap_read(priv->map_reg, MCP251XFD_REG_CRC, &crc);
1389 	if (err)
1390 		return err;
1391 
1392 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_CRC,
1393 				 MCP251XFD_REG_CRC_IF_MASK,
1394 				 ~crc);
1395 	if (err)
1396 		return err;
1397 
1398 	if (crc & MCP251XFD_REG_CRC_FERRIF)
1399 		netdev_notice(priv->ndev, "CRC write command format error.\n");
1400 	else if (crc & MCP251XFD_REG_CRC_CRCERRIF)
1401 		netdev_notice(priv->ndev,
1402 			      "CRC write error detected. CRC=0x%04lx.\n",
1403 			      FIELD_GET(MCP251XFD_REG_CRC_MASK, crc));
1404 
1405 	return 0;
1406 }
1407 
1408 static int mcp251xfd_read_regs_status(struct mcp251xfd_priv *priv)
1409 {
1410 	const int val_bytes = regmap_get_val_bytes(priv->map_reg);
1411 	size_t len;
1412 
1413 	if (priv->rx_ring_num == 1)
1414 		len = sizeof(priv->regs_status.intf);
1415 	else
1416 		len = sizeof(priv->regs_status);
1417 
1418 	return regmap_bulk_read(priv->map_reg, MCP251XFD_REG_INT,
1419 				&priv->regs_status, len / val_bytes);
1420 }
1421 
1422 #define mcp251xfd_handle(priv, irq, ...) \
1423 ({ \
1424 	struct mcp251xfd_priv *_priv = (priv); \
1425 	int err; \
1426 \
1427 	err = mcp251xfd_handle_##irq(_priv, ## __VA_ARGS__); \
1428 	if (err) \
1429 		netdev_err(_priv->ndev, \
1430 			"IRQ handler mcp251xfd_handle_%s() returned %d.\n", \
1431 			__stringify(irq), err); \
1432 	err; \
1433 })
1434 
1435 static irqreturn_t mcp251xfd_irq(int irq, void *dev_id)
1436 {
1437 	struct mcp251xfd_priv *priv = dev_id;
1438 	irqreturn_t handled = IRQ_NONE;
1439 	int err;
1440 
1441 	if (priv->rx_int)
1442 		do {
1443 			int rx_pending;
1444 
1445 			rx_pending = gpiod_get_value_cansleep(priv->rx_int);
1446 			if (!rx_pending)
1447 				break;
1448 
1449 			/* Assume 1st RX-FIFO pending, if other FIFOs
1450 			 * are pending the main IRQ handler will take
1451 			 * care.
1452 			 */
1453 			priv->regs_status.rxif = BIT(priv->rx[0]->fifo_nr);
1454 			err = mcp251xfd_handle(priv, rxif);
1455 			if (err)
1456 				goto out_fail;
1457 
1458 			handled = IRQ_HANDLED;
1459 
1460 			/* We don't know which RX-FIFO is pending, but only
1461 			 * handle the 1st RX-FIFO. Leave loop here if we have
1462 			 * more than 1 RX-FIFO to avoid starvation.
1463 			 */
1464 		} while (priv->rx_ring_num == 1);
1465 
1466 	do {
1467 		u32 intf_pending, intf_pending_clearable;
1468 		bool set_normal_mode = false;
1469 
1470 		err = mcp251xfd_read_regs_status(priv);
1471 		if (err)
1472 			goto out_fail;
1473 
1474 		intf_pending = FIELD_GET(MCP251XFD_REG_INT_IF_MASK,
1475 					 priv->regs_status.intf) &
1476 			FIELD_GET(MCP251XFD_REG_INT_IE_MASK,
1477 				  priv->regs_status.intf);
1478 
1479 		if (!(intf_pending)) {
1480 			can_rx_offload_threaded_irq_finish(&priv->offload);
1481 			return handled;
1482 		}
1483 
1484 		/* Some interrupts must be ACKed in the
1485 		 * MCP251XFD_REG_INT register.
1486 		 * - First ACK then handle, to avoid lost-IRQ race
1487 		 *   condition on fast re-occurring interrupts.
1488 		 * - Write "0" to clear active IRQs, "1" to all other,
1489 		 *   to avoid r/m/w race condition on the
1490 		 *   MCP251XFD_REG_INT register.
1491 		 */
1492 		intf_pending_clearable = intf_pending &
1493 			MCP251XFD_REG_INT_IF_CLEARABLE_MASK;
1494 		if (intf_pending_clearable) {
1495 			err = regmap_update_bits(priv->map_reg,
1496 						 MCP251XFD_REG_INT,
1497 						 MCP251XFD_REG_INT_IF_MASK,
1498 						 ~intf_pending_clearable);
1499 			if (err)
1500 				goto out_fail;
1501 		}
1502 
1503 		if (intf_pending & MCP251XFD_REG_INT_MODIF) {
1504 			err = mcp251xfd_handle(priv, modif, &set_normal_mode);
1505 			if (err)
1506 				goto out_fail;
1507 		}
1508 
1509 		if (intf_pending & MCP251XFD_REG_INT_RXIF) {
1510 			err = mcp251xfd_handle(priv, rxif);
1511 			if (err)
1512 				goto out_fail;
1513 		}
1514 
1515 		if (intf_pending & MCP251XFD_REG_INT_TEFIF) {
1516 			err = mcp251xfd_handle(priv, tefif);
1517 			if (err)
1518 				goto out_fail;
1519 		}
1520 
1521 		if (intf_pending & MCP251XFD_REG_INT_RXOVIF) {
1522 			err = mcp251xfd_handle(priv, rxovif);
1523 			if (err)
1524 				goto out_fail;
1525 		}
1526 
1527 		if (intf_pending & MCP251XFD_REG_INT_TXATIF) {
1528 			err = mcp251xfd_handle(priv, txatif);
1529 			if (err)
1530 				goto out_fail;
1531 		}
1532 
1533 		if (intf_pending & MCP251XFD_REG_INT_IVMIF) {
1534 			err = mcp251xfd_handle(priv, ivmif);
1535 			if (err)
1536 				goto out_fail;
1537 		}
1538 
1539 		if (intf_pending & MCP251XFD_REG_INT_SERRIF) {
1540 			err = mcp251xfd_handle(priv, serrif);
1541 			if (err)
1542 				goto out_fail;
1543 		}
1544 
1545 		if (intf_pending & MCP251XFD_REG_INT_ECCIF) {
1546 			err = mcp251xfd_handle(priv, eccif, set_normal_mode);
1547 			if (err)
1548 				goto out_fail;
1549 		}
1550 
1551 		if (intf_pending & MCP251XFD_REG_INT_SPICRCIF) {
1552 			err = mcp251xfd_handle(priv, spicrcif);
1553 			if (err)
1554 				goto out_fail;
1555 		}
1556 
1557 		/* On the MCP2527FD and MCP2518FD, we don't get a
1558 		 * CERRIF IRQ on the transition TX ERROR_WARNING -> TX
1559 		 * ERROR_ACTIVE.
1560 		 */
1561 		if (intf_pending & MCP251XFD_REG_INT_CERRIF ||
1562 		    priv->can.state > CAN_STATE_ERROR_ACTIVE) {
1563 			err = mcp251xfd_handle(priv, cerrif);
1564 			if (err)
1565 				goto out_fail;
1566 
1567 			/* In Bus Off we completely shut down the
1568 			 * controller. Every subsequent register read
1569 			 * will read bogus data, and if
1570 			 * MCP251XFD_QUIRK_CRC_REG is enabled the CRC
1571 			 * check will fail, too. So leave IRQ handler
1572 			 * directly.
1573 			 */
1574 			if (priv->can.state == CAN_STATE_BUS_OFF) {
1575 				can_rx_offload_threaded_irq_finish(&priv->offload);
1576 				return IRQ_HANDLED;
1577 			}
1578 		}
1579 
1580 		handled = IRQ_HANDLED;
1581 	} while (1);
1582 
1583 out_fail:
1584 	can_rx_offload_threaded_irq_finish(&priv->offload);
1585 
1586 	netdev_err(priv->ndev, "IRQ handler returned %d (intf=0x%08x).\n",
1587 		   err, priv->regs_status.intf);
1588 	mcp251xfd_dump(priv);
1589 	mcp251xfd_chip_interrupts_disable(priv);
1590 	mcp251xfd_timestamp_stop(priv);
1591 
1592 	return handled;
1593 }
1594 
1595 static int mcp251xfd_open(struct net_device *ndev)
1596 {
1597 	struct mcp251xfd_priv *priv = netdev_priv(ndev);
1598 	const struct spi_device *spi = priv->spi;
1599 	int err;
1600 
1601 	err = open_candev(ndev);
1602 	if (err)
1603 		return err;
1604 
1605 	err = pm_runtime_resume_and_get(ndev->dev.parent);
1606 	if (err)
1607 		goto out_close_candev;
1608 
1609 	err = mcp251xfd_ring_alloc(priv);
1610 	if (err)
1611 		goto out_pm_runtime_put;
1612 
1613 	err = mcp251xfd_transceiver_enable(priv);
1614 	if (err)
1615 		goto out_mcp251xfd_ring_free;
1616 
1617 	mcp251xfd_timestamp_init(priv);
1618 
1619 	err = mcp251xfd_chip_start(priv);
1620 	if (err)
1621 		goto out_transceiver_disable;
1622 
1623 	clear_bit(MCP251XFD_FLAGS_DOWN, priv->flags);
1624 	can_rx_offload_enable(&priv->offload);
1625 
1626 	priv->wq = alloc_ordered_workqueue("%s-mcp251xfd_wq",
1627 					   WQ_FREEZABLE | WQ_MEM_RECLAIM,
1628 					   dev_name(&spi->dev));
1629 	if (!priv->wq) {
1630 		err = -ENOMEM;
1631 		goto out_can_rx_offload_disable;
1632 	}
1633 	INIT_WORK(&priv->tx_work, mcp251xfd_tx_obj_write_sync);
1634 
1635 	err = request_threaded_irq(spi->irq, NULL, mcp251xfd_irq,
1636 				   IRQF_SHARED | IRQF_ONESHOT,
1637 				   dev_name(&spi->dev), priv);
1638 	if (err)
1639 		goto out_destroy_workqueue;
1640 
1641 	err = mcp251xfd_chip_interrupts_enable(priv);
1642 	if (err)
1643 		goto out_free_irq;
1644 
1645 	netif_start_queue(ndev);
1646 
1647 	return 0;
1648 
1649 out_free_irq:
1650 	free_irq(spi->irq, priv);
1651 out_destroy_workqueue:
1652 	destroy_workqueue(priv->wq);
1653 out_can_rx_offload_disable:
1654 	can_rx_offload_disable(&priv->offload);
1655 	set_bit(MCP251XFD_FLAGS_DOWN, priv->flags);
1656 out_transceiver_disable:
1657 	mcp251xfd_transceiver_disable(priv);
1658 out_mcp251xfd_ring_free:
1659 	mcp251xfd_ring_free(priv);
1660 out_pm_runtime_put:
1661 	mcp251xfd_chip_stop(priv, CAN_STATE_STOPPED);
1662 	pm_runtime_put(ndev->dev.parent);
1663 out_close_candev:
1664 	close_candev(ndev);
1665 
1666 	return err;
1667 }
1668 
1669 static int mcp251xfd_stop(struct net_device *ndev)
1670 {
1671 	struct mcp251xfd_priv *priv = netdev_priv(ndev);
1672 
1673 	netif_stop_queue(ndev);
1674 	set_bit(MCP251XFD_FLAGS_DOWN, priv->flags);
1675 	hrtimer_cancel(&priv->rx_irq_timer);
1676 	hrtimer_cancel(&priv->tx_irq_timer);
1677 	mcp251xfd_chip_interrupts_disable(priv);
1678 	free_irq(ndev->irq, priv);
1679 	destroy_workqueue(priv->wq);
1680 	can_rx_offload_disable(&priv->offload);
1681 	mcp251xfd_chip_stop(priv, CAN_STATE_STOPPED);
1682 	mcp251xfd_transceiver_disable(priv);
1683 	mcp251xfd_ring_free(priv);
1684 	close_candev(ndev);
1685 
1686 	pm_runtime_put(ndev->dev.parent);
1687 
1688 	return 0;
1689 }
1690 
1691 static const struct net_device_ops mcp251xfd_netdev_ops = {
1692 	.ndo_open = mcp251xfd_open,
1693 	.ndo_stop = mcp251xfd_stop,
1694 	.ndo_start_xmit	= mcp251xfd_start_xmit,
1695 	.ndo_eth_ioctl = can_eth_ioctl_hwts,
1696 	.ndo_change_mtu = can_change_mtu,
1697 };
1698 
1699 static void
1700 mcp251xfd_register_quirks(struct mcp251xfd_priv *priv)
1701 {
1702 	const struct spi_device *spi = priv->spi;
1703 	const struct spi_controller *ctlr = spi->controller;
1704 
1705 	if (ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX)
1706 		priv->devtype_data.quirks |= MCP251XFD_QUIRK_HALF_DUPLEX;
1707 }
1708 
1709 static int mcp251xfd_register_chip_detect(struct mcp251xfd_priv *priv)
1710 {
1711 	const struct net_device *ndev = priv->ndev;
1712 	const struct mcp251xfd_devtype_data *devtype_data;
1713 	u32 osc;
1714 	int err;
1715 
1716 	/* The OSC_LPMEN is only supported on MCP2518FD and MCP251863,
1717 	 * so use it to autodetect the model.
1718 	 */
1719 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_OSC,
1720 				 MCP251XFD_REG_OSC_LPMEN,
1721 				 MCP251XFD_REG_OSC_LPMEN);
1722 	if (err)
1723 		return err;
1724 
1725 	err = regmap_read(priv->map_reg, MCP251XFD_REG_OSC, &osc);
1726 	if (err)
1727 		return err;
1728 
1729 	if (osc & MCP251XFD_REG_OSC_LPMEN) {
1730 		/* We cannot distinguish between MCP2518FD and
1731 		 * MCP251863. If firmware specifies MCP251863, keep
1732 		 * it, otherwise set to MCP2518FD.
1733 		 */
1734 		if (mcp251xfd_is_251863(priv))
1735 			devtype_data = &mcp251xfd_devtype_data_mcp251863;
1736 		else
1737 			devtype_data = &mcp251xfd_devtype_data_mcp2518fd;
1738 	} else {
1739 		devtype_data = &mcp251xfd_devtype_data_mcp2517fd;
1740 	}
1741 
1742 	if (!mcp251xfd_is_251XFD(priv) &&
1743 	    priv->devtype_data.model != devtype_data->model) {
1744 		netdev_info(ndev,
1745 			    "Detected %s, but firmware specifies a %s. Fixing up.\n",
1746 			    __mcp251xfd_get_model_str(devtype_data->model),
1747 			    mcp251xfd_get_model_str(priv));
1748 	}
1749 	priv->devtype_data = *devtype_data;
1750 
1751 	/* We need to preserve the Half Duplex Quirk. */
1752 	mcp251xfd_register_quirks(priv);
1753 
1754 	/* Re-init regmap with quirks of detected model. */
1755 	return mcp251xfd_regmap_init(priv);
1756 }
1757 
1758 static int mcp251xfd_register_check_rx_int(struct mcp251xfd_priv *priv)
1759 {
1760 	int err, rx_pending;
1761 
1762 	if (!priv->rx_int)
1763 		return 0;
1764 
1765 	err = mcp251xfd_chip_rx_int_enable(priv);
1766 	if (err)
1767 		return err;
1768 
1769 	/* Check if RX_INT is properly working. The RX_INT should not
1770 	 * be active after a softreset.
1771 	 */
1772 	rx_pending = gpiod_get_value_cansleep(priv->rx_int);
1773 
1774 	err = mcp251xfd_chip_rx_int_disable(priv);
1775 	if (err)
1776 		return err;
1777 
1778 	if (!rx_pending)
1779 		return 0;
1780 
1781 	netdev_info(priv->ndev,
1782 		    "RX_INT active after softreset, disabling RX_INT support.\n");
1783 	devm_gpiod_put(&priv->spi->dev, priv->rx_int);
1784 	priv->rx_int = NULL;
1785 
1786 	return 0;
1787 }
1788 
1789 static int
1790 mcp251xfd_register_get_dev_id(const struct mcp251xfd_priv *priv, u32 *dev_id,
1791 			      u32 *effective_speed_hz_slow,
1792 			      u32 *effective_speed_hz_fast)
1793 {
1794 	struct mcp251xfd_map_buf_nocrc *buf_rx;
1795 	struct mcp251xfd_map_buf_nocrc *buf_tx;
1796 	struct spi_transfer xfer[2] = { };
1797 	int err;
1798 
1799 	buf_rx = kzalloc(sizeof(*buf_rx), GFP_KERNEL);
1800 	if (!buf_rx)
1801 		return -ENOMEM;
1802 
1803 	buf_tx = kzalloc(sizeof(*buf_tx), GFP_KERNEL);
1804 	if (!buf_tx) {
1805 		err = -ENOMEM;
1806 		goto out_kfree_buf_rx;
1807 	}
1808 
1809 	xfer[0].tx_buf = buf_tx;
1810 	xfer[0].len = sizeof(buf_tx->cmd);
1811 	xfer[0].speed_hz = priv->spi_max_speed_hz_slow;
1812 	xfer[1].rx_buf = buf_rx->data;
1813 	xfer[1].len = sizeof(*dev_id);
1814 	xfer[1].speed_hz = priv->spi_max_speed_hz_fast;
1815 
1816 	mcp251xfd_spi_cmd_read_nocrc(&buf_tx->cmd, MCP251XFD_REG_DEVID);
1817 
1818 	err = spi_sync_transfer(priv->spi, xfer, ARRAY_SIZE(xfer));
1819 	if (err)
1820 		goto out_kfree_buf_tx;
1821 
1822 	*dev_id = get_unaligned_le32(buf_rx->data);
1823 	*effective_speed_hz_slow = xfer[0].effective_speed_hz;
1824 	*effective_speed_hz_fast = xfer[1].effective_speed_hz;
1825 
1826 out_kfree_buf_tx:
1827 	kfree(buf_tx);
1828 out_kfree_buf_rx:
1829 	kfree(buf_rx);
1830 
1831 	return err;
1832 }
1833 
1834 #define MCP251XFD_QUIRK_ACTIVE(quirk) \
1835 	(priv->devtype_data.quirks & MCP251XFD_QUIRK_##quirk ? '+' : '-')
1836 
1837 static int
1838 mcp251xfd_register_done(const struct mcp251xfd_priv *priv)
1839 {
1840 	u32 dev_id, effective_speed_hz_slow, effective_speed_hz_fast;
1841 	unsigned long clk_rate;
1842 	int err;
1843 
1844 	err = mcp251xfd_register_get_dev_id(priv, &dev_id,
1845 					    &effective_speed_hz_slow,
1846 					    &effective_speed_hz_fast);
1847 	if (err)
1848 		return err;
1849 
1850 	clk_rate = clk_get_rate(priv->clk);
1851 
1852 	netdev_info(priv->ndev,
1853 		    "%s rev%lu.%lu (%cRX_INT %cPLL %cMAB_NO_WARN %cCRC_REG %cCRC_RX %cCRC_TX %cECC %cHD o:%lu.%02luMHz c:%u.%02uMHz m:%u.%02uMHz rs:%u.%02uMHz es:%u.%02uMHz rf:%u.%02uMHz ef:%u.%02uMHz) successfully initialized.\n",
1854 		    mcp251xfd_get_model_str(priv),
1855 		    FIELD_GET(MCP251XFD_REG_DEVID_ID_MASK, dev_id),
1856 		    FIELD_GET(MCP251XFD_REG_DEVID_REV_MASK, dev_id),
1857 		    priv->rx_int ? '+' : '-',
1858 		    priv->pll_enable ? '+' : '-',
1859 		    MCP251XFD_QUIRK_ACTIVE(MAB_NO_WARN),
1860 		    MCP251XFD_QUIRK_ACTIVE(CRC_REG),
1861 		    MCP251XFD_QUIRK_ACTIVE(CRC_RX),
1862 		    MCP251XFD_QUIRK_ACTIVE(CRC_TX),
1863 		    MCP251XFD_QUIRK_ACTIVE(ECC),
1864 		    MCP251XFD_QUIRK_ACTIVE(HALF_DUPLEX),
1865 		    clk_rate / 1000000,
1866 		    clk_rate % 1000000 / 1000 / 10,
1867 		    priv->can.clock.freq / 1000000,
1868 		    priv->can.clock.freq % 1000000 / 1000 / 10,
1869 		    priv->spi_max_speed_hz_orig / 1000000,
1870 		    priv->spi_max_speed_hz_orig % 1000000 / 1000 / 10,
1871 		    priv->spi_max_speed_hz_slow / 1000000,
1872 		    priv->spi_max_speed_hz_slow % 1000000 / 1000 / 10,
1873 		    effective_speed_hz_slow / 1000000,
1874 		    effective_speed_hz_slow % 1000000 / 1000 / 10,
1875 		    priv->spi_max_speed_hz_fast / 1000000,
1876 		    priv->spi_max_speed_hz_fast % 1000000 / 1000 / 10,
1877 		    effective_speed_hz_fast / 1000000,
1878 		    effective_speed_hz_fast % 1000000 / 1000 / 10);
1879 
1880 	return 0;
1881 }
1882 
1883 static int mcp251xfd_register(struct mcp251xfd_priv *priv)
1884 {
1885 	struct net_device *ndev = priv->ndev;
1886 	int err;
1887 
1888 	err = mcp251xfd_clks_and_vdd_enable(priv);
1889 	if (err)
1890 		return err;
1891 
1892 	pm_runtime_get_noresume(ndev->dev.parent);
1893 	err = pm_runtime_set_active(ndev->dev.parent);
1894 	if (err)
1895 		goto out_runtime_put_noidle;
1896 	pm_runtime_enable(ndev->dev.parent);
1897 
1898 	mcp251xfd_register_quirks(priv);
1899 
1900 	err = mcp251xfd_chip_softreset(priv);
1901 	if (err == -ENODEV)
1902 		goto out_runtime_disable;
1903 	if (err)
1904 		goto out_chip_sleep;
1905 
1906 	err = mcp251xfd_chip_clock_init(priv);
1907 	if (err == -ENODEV)
1908 		goto out_runtime_disable;
1909 	if (err)
1910 		goto out_chip_sleep;
1911 
1912 	err = mcp251xfd_register_chip_detect(priv);
1913 	if (err)
1914 		goto out_chip_sleep;
1915 
1916 	err = mcp251xfd_register_check_rx_int(priv);
1917 	if (err)
1918 		goto out_chip_sleep;
1919 
1920 	mcp251xfd_ethtool_init(priv);
1921 
1922 	err = register_candev(ndev);
1923 	if (err)
1924 		goto out_chip_sleep;
1925 
1926 	err = mcp251xfd_register_done(priv);
1927 	if (err)
1928 		goto out_unregister_candev;
1929 
1930 	/* Put controller into sleep mode and let pm_runtime_put()
1931 	 * disable the clocks and vdd. If CONFIG_PM is not enabled,
1932 	 * the clocks and vdd will stay powered.
1933 	 */
1934 	err = mcp251xfd_chip_sleep(priv);
1935 	if (err)
1936 		goto out_unregister_candev;
1937 
1938 	pm_runtime_put(ndev->dev.parent);
1939 
1940 	return 0;
1941 
1942 out_unregister_candev:
1943 	unregister_candev(ndev);
1944 out_chip_sleep:
1945 	mcp251xfd_chip_sleep(priv);
1946 out_runtime_disable:
1947 	pm_runtime_disable(ndev->dev.parent);
1948 out_runtime_put_noidle:
1949 	pm_runtime_put_noidle(ndev->dev.parent);
1950 	mcp251xfd_clks_and_vdd_disable(priv);
1951 
1952 	return err;
1953 }
1954 
1955 static inline void mcp251xfd_unregister(struct mcp251xfd_priv *priv)
1956 {
1957 	struct net_device *ndev	= priv->ndev;
1958 
1959 	unregister_candev(ndev);
1960 
1961 	if (pm_runtime_enabled(ndev->dev.parent))
1962 		pm_runtime_disable(ndev->dev.parent);
1963 	else
1964 		mcp251xfd_clks_and_vdd_disable(priv);
1965 }
1966 
1967 static const struct of_device_id mcp251xfd_of_match[] = {
1968 	{
1969 		.compatible = "microchip,mcp2517fd",
1970 		.data = &mcp251xfd_devtype_data_mcp2517fd,
1971 	}, {
1972 		.compatible = "microchip,mcp2518fd",
1973 		.data = &mcp251xfd_devtype_data_mcp2518fd,
1974 	}, {
1975 		.compatible = "microchip,mcp251863",
1976 		.data = &mcp251xfd_devtype_data_mcp251863,
1977 	}, {
1978 		.compatible = "microchip,mcp251xfd",
1979 		.data = &mcp251xfd_devtype_data_mcp251xfd,
1980 	}, {
1981 		/* sentinel */
1982 	},
1983 };
1984 MODULE_DEVICE_TABLE(of, mcp251xfd_of_match);
1985 
1986 static const struct spi_device_id mcp251xfd_id_table[] = {
1987 	{
1988 		.name = "mcp2517fd",
1989 		.driver_data = (kernel_ulong_t)&mcp251xfd_devtype_data_mcp2517fd,
1990 	}, {
1991 		.name = "mcp2518fd",
1992 		.driver_data = (kernel_ulong_t)&mcp251xfd_devtype_data_mcp2518fd,
1993 	}, {
1994 		.name = "mcp251863",
1995 		.driver_data = (kernel_ulong_t)&mcp251xfd_devtype_data_mcp251863,
1996 	}, {
1997 		.name = "mcp251xfd",
1998 		.driver_data = (kernel_ulong_t)&mcp251xfd_devtype_data_mcp251xfd,
1999 	}, {
2000 		/* sentinel */
2001 	},
2002 };
2003 MODULE_DEVICE_TABLE(spi, mcp251xfd_id_table);
2004 
2005 static int mcp251xfd_probe(struct spi_device *spi)
2006 {
2007 	struct net_device *ndev;
2008 	struct mcp251xfd_priv *priv;
2009 	struct gpio_desc *rx_int;
2010 	struct regulator *reg_vdd, *reg_xceiver;
2011 	struct clk *clk;
2012 	bool pll_enable = false;
2013 	u32 freq = 0;
2014 	int err;
2015 
2016 	if (!spi->irq)
2017 		return dev_err_probe(&spi->dev, -ENXIO,
2018 				     "No IRQ specified (maybe node \"interrupts-extended\" in DT missing)!\n");
2019 
2020 	rx_int = devm_gpiod_get_optional(&spi->dev, "microchip,rx-int",
2021 					 GPIOD_IN);
2022 	if (IS_ERR(rx_int))
2023 		return dev_err_probe(&spi->dev, PTR_ERR(rx_int),
2024 				     "Failed to get RX-INT!\n");
2025 
2026 	reg_vdd = devm_regulator_get_optional(&spi->dev, "vdd");
2027 	if (PTR_ERR(reg_vdd) == -ENODEV)
2028 		reg_vdd = NULL;
2029 	else if (IS_ERR(reg_vdd))
2030 		return dev_err_probe(&spi->dev, PTR_ERR(reg_vdd),
2031 				     "Failed to get VDD regulator!\n");
2032 
2033 	reg_xceiver = devm_regulator_get_optional(&spi->dev, "xceiver");
2034 	if (PTR_ERR(reg_xceiver) == -ENODEV)
2035 		reg_xceiver = NULL;
2036 	else if (IS_ERR(reg_xceiver))
2037 		return dev_err_probe(&spi->dev, PTR_ERR(reg_xceiver),
2038 				     "Failed to get Transceiver regulator!\n");
2039 
2040 	clk = devm_clk_get_optional(&spi->dev, NULL);
2041 	if (IS_ERR(clk))
2042 		return dev_err_probe(&spi->dev, PTR_ERR(clk),
2043 				     "Failed to get Oscillator (clock)!\n");
2044 	if (clk) {
2045 		freq = clk_get_rate(clk);
2046 	} else {
2047 		err = device_property_read_u32(&spi->dev, "clock-frequency",
2048 					       &freq);
2049 		if (err)
2050 			return dev_err_probe(&spi->dev, err,
2051 					     "Failed to get clock-frequency!\n");
2052 	}
2053 
2054 	/* Sanity check */
2055 	if (freq < MCP251XFD_SYSCLOCK_HZ_MIN ||
2056 	    freq > MCP251XFD_SYSCLOCK_HZ_MAX) {
2057 		dev_err(&spi->dev,
2058 			"Oscillator frequency (%u Hz) is too low or high.\n",
2059 			freq);
2060 		return -ERANGE;
2061 	}
2062 
2063 	if (freq <= MCP251XFD_SYSCLOCK_HZ_MAX / MCP251XFD_OSC_PLL_MULTIPLIER)
2064 		pll_enable = true;
2065 
2066 	ndev = alloc_candev(sizeof(struct mcp251xfd_priv),
2067 			    MCP251XFD_TX_OBJ_NUM_MAX);
2068 	if (!ndev)
2069 		return -ENOMEM;
2070 
2071 	SET_NETDEV_DEV(ndev, &spi->dev);
2072 
2073 	ndev->netdev_ops = &mcp251xfd_netdev_ops;
2074 	ndev->irq = spi->irq;
2075 	ndev->flags |= IFF_ECHO;
2076 
2077 	priv = netdev_priv(ndev);
2078 	spi_set_drvdata(spi, priv);
2079 	priv->can.clock.freq = freq;
2080 	if (pll_enable)
2081 		priv->can.clock.freq *= MCP251XFD_OSC_PLL_MULTIPLIER;
2082 	priv->can.do_set_mode = mcp251xfd_set_mode;
2083 	priv->can.do_get_berr_counter = mcp251xfd_get_berr_counter;
2084 	priv->can.bittiming_const = &mcp251xfd_bittiming_const;
2085 	priv->can.data_bittiming_const = &mcp251xfd_data_bittiming_const;
2086 	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
2087 		CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_BERR_REPORTING |
2088 		CAN_CTRLMODE_FD | CAN_CTRLMODE_FD_NON_ISO |
2089 		CAN_CTRLMODE_CC_LEN8_DLC;
2090 	set_bit(MCP251XFD_FLAGS_DOWN, priv->flags);
2091 	priv->ndev = ndev;
2092 	priv->spi = spi;
2093 	priv->rx_int = rx_int;
2094 	priv->clk = clk;
2095 	priv->pll_enable = pll_enable;
2096 	priv->reg_vdd = reg_vdd;
2097 	priv->reg_xceiver = reg_xceiver;
2098 	priv->devtype_data = *(struct mcp251xfd_devtype_data *)spi_get_device_match_data(spi);
2099 
2100 	/* Errata Reference:
2101 	 * mcp2517fd: DS80000792C 5., mcp2518fd: DS80000789E 4.,
2102 	 * mcp251863: DS80000984A 4.
2103 	 *
2104 	 * The SPI can write corrupted data to the RAM at fast SPI
2105 	 * speeds:
2106 	 *
2107 	 * Simultaneous activity on the CAN bus while writing data to
2108 	 * RAM via the SPI interface, with high SCK frequency, can
2109 	 * lead to corrupted data being written to RAM.
2110 	 *
2111 	 * Fix/Work Around:
2112 	 * Ensure that FSCK is less than or equal to 0.85 *
2113 	 * (FSYSCLK/2).
2114 	 *
2115 	 * Known good combinations are:
2116 	 *
2117 	 * MCP	ext-clk	SoC			SPI			SPI-clk		max-clk	parent-clk	config
2118 	 *
2119 	 * 2518	20 MHz	allwinner,sun8i-h3	allwinner,sun8i-h3-spi	 8333333 Hz	 83.33%	600000000 Hz	assigned-clocks = <&ccu CLK_SPIx>
2120 	 * 2518	40 MHz	allwinner,sun8i-h3	allwinner,sun8i-h3-spi	16666667 Hz	 83.33%	600000000 Hz	assigned-clocks = <&ccu CLK_SPIx>
2121 	 * 2517	40 MHz	atmel,sama5d27		atmel,at91rm9200-spi	16400000 Hz	 82.00%	 82000000 Hz	default
2122 	 * 2518	40 MHz	atmel,sama5d27		atmel,at91rm9200-spi	16400000 Hz	 82.00%	 82000000 Hz	default
2123 	 * 2518	40 MHz	fsl,imx6dl		fsl,imx51-ecspi		15000000 Hz	 75.00%	 30000000 Hz	default
2124 	 * 2517	20 MHz	fsl,imx8mm		fsl,imx51-ecspi		 8333333 Hz	 83.33%	 16666667 Hz	assigned-clocks = <&clk IMX8MM_CLK_ECSPIx_ROOT>
2125 	 *
2126 	 */
2127 	priv->spi_max_speed_hz_orig = spi->max_speed_hz;
2128 	priv->spi_max_speed_hz_slow = min(spi->max_speed_hz,
2129 					  freq / 2 / 1000 * 850);
2130 	if (priv->pll_enable)
2131 		priv->spi_max_speed_hz_fast = min(spi->max_speed_hz,
2132 						  freq *
2133 						  MCP251XFD_OSC_PLL_MULTIPLIER /
2134 						  2 / 1000 * 850);
2135 	else
2136 		priv->spi_max_speed_hz_fast = priv->spi_max_speed_hz_slow;
2137 	spi->max_speed_hz = priv->spi_max_speed_hz_slow;
2138 	spi->bits_per_word = 8;
2139 	spi->rt = true;
2140 	err = spi_setup(spi);
2141 	if (err)
2142 		goto out_free_candev;
2143 
2144 	err = mcp251xfd_regmap_init(priv);
2145 	if (err)
2146 		goto out_free_candev;
2147 
2148 	err = can_rx_offload_add_manual(ndev, &priv->offload,
2149 					MCP251XFD_NAPI_WEIGHT);
2150 	if (err)
2151 		goto out_free_candev;
2152 
2153 	err = mcp251xfd_register(priv);
2154 	if (err) {
2155 		dev_err_probe(&spi->dev, err, "Failed to detect %s.\n",
2156 			      mcp251xfd_get_model_str(priv));
2157 		goto out_can_rx_offload_del;
2158 	}
2159 
2160 	return 0;
2161 
2162 out_can_rx_offload_del:
2163 	can_rx_offload_del(&priv->offload);
2164 out_free_candev:
2165 	spi->max_speed_hz = priv->spi_max_speed_hz_orig;
2166 
2167 	free_candev(ndev);
2168 
2169 	return err;
2170 }
2171 
2172 static void mcp251xfd_remove(struct spi_device *spi)
2173 {
2174 	struct mcp251xfd_priv *priv = spi_get_drvdata(spi);
2175 	struct net_device *ndev = priv->ndev;
2176 
2177 	can_rx_offload_del(&priv->offload);
2178 	mcp251xfd_unregister(priv);
2179 	spi->max_speed_hz = priv->spi_max_speed_hz_orig;
2180 	free_candev(ndev);
2181 }
2182 
2183 static int __maybe_unused mcp251xfd_runtime_suspend(struct device *device)
2184 {
2185 	const struct mcp251xfd_priv *priv = dev_get_drvdata(device);
2186 
2187 	return mcp251xfd_clks_and_vdd_disable(priv);
2188 }
2189 
2190 static int __maybe_unused mcp251xfd_runtime_resume(struct device *device)
2191 {
2192 	const struct mcp251xfd_priv *priv = dev_get_drvdata(device);
2193 
2194 	return mcp251xfd_clks_and_vdd_enable(priv);
2195 }
2196 
2197 static const struct dev_pm_ops mcp251xfd_pm_ops = {
2198 	SET_RUNTIME_PM_OPS(mcp251xfd_runtime_suspend,
2199 			   mcp251xfd_runtime_resume, NULL)
2200 };
2201 
2202 static struct spi_driver mcp251xfd_driver = {
2203 	.driver = {
2204 		.name = DEVICE_NAME,
2205 		.pm = &mcp251xfd_pm_ops,
2206 		.of_match_table = mcp251xfd_of_match,
2207 	},
2208 	.probe = mcp251xfd_probe,
2209 	.remove = mcp251xfd_remove,
2210 	.id_table = mcp251xfd_id_table,
2211 };
2212 module_spi_driver(mcp251xfd_driver);
2213 
2214 MODULE_AUTHOR("Marc Kleine-Budde <mkl@pengutronix.de>");
2215 MODULE_DESCRIPTION("Microchip MCP251xFD Family CAN controller driver");
2216 MODULE_LICENSE("GPL v2");
2217