1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // mcp251xfd - Microchip MCP251xFD Family CAN controller driver
4 //
5 // Copyright (c) 2019, 2020, 2021 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 <asm/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 	u32 con = 0, con_reqop, osc = 0;
231 	u8 mode;
232 	int err;
233 
234 	con_reqop = FIELD_PREP(MCP251XFD_REG_CON_REQOP_MASK, mode_req);
235 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_CON,
236 				 MCP251XFD_REG_CON_REQOP_MASK, con_reqop);
237 	if (err == -EBADMSG) {
238 		netdev_err(priv->ndev,
239 			   "Failed to set Requested Operation Mode.\n");
240 
241 		return -ENODEV;
242 	} else if (err) {
243 		return err;
244 	}
245 
246 	if (mode_req == MCP251XFD_REG_CON_MODE_SLEEP || nowait)
247 		return 0;
248 
249 	err = regmap_read_poll_timeout(priv->map_reg, MCP251XFD_REG_CON, con,
250 				       !mcp251xfd_reg_invalid(con) &&
251 				       FIELD_GET(MCP251XFD_REG_CON_OPMOD_MASK,
252 						 con) == mode_req,
253 				       MCP251XFD_POLL_SLEEP_US,
254 				       MCP251XFD_POLL_TIMEOUT_US);
255 	if (err != -ETIMEDOUT && err != -EBADMSG)
256 		return err;
257 
258 	/* Ignore return value.
259 	 * Print below error messages, even if this fails.
260 	 */
261 	regmap_read(priv->map_reg, MCP251XFD_REG_OSC, &osc);
262 
263 	if (mcp251xfd_reg_invalid(con)) {
264 		netdev_err(priv->ndev,
265 			   "Failed to read CAN Control Register (con=0x%08x, osc=0x%08x).\n",
266 			   con, osc);
267 
268 		return -ENODEV;
269 	}
270 
271 	mode = FIELD_GET(MCP251XFD_REG_CON_OPMOD_MASK, con);
272 	netdev_err(priv->ndev,
273 		   "Controller failed to enter mode %s Mode (%u) and stays in %s Mode (%u) (con=0x%08x, osc=0x%08x).\n",
274 		   mcp251xfd_get_mode_str(mode_req), mode_req,
275 		   mcp251xfd_get_mode_str(mode), mode,
276 		   con, osc);
277 
278 	return -ETIMEDOUT;
279 }
280 
281 static inline int
282 mcp251xfd_chip_set_mode(const struct mcp251xfd_priv *priv,
283 			const u8 mode_req)
284 {
285 	return __mcp251xfd_chip_set_mode(priv, mode_req, false);
286 }
287 
288 static inline int __maybe_unused
289 mcp251xfd_chip_set_mode_nowait(const struct mcp251xfd_priv *priv,
290 			       const u8 mode_req)
291 {
292 	return __mcp251xfd_chip_set_mode(priv, mode_req, true);
293 }
294 
295 static int
296 mcp251xfd_chip_wait_for_osc_ready(const struct mcp251xfd_priv *priv,
297 				  u32 osc_reference, u32 osc_mask)
298 {
299 	u32 osc;
300 	int err;
301 
302 	err = regmap_read_poll_timeout(priv->map_reg, MCP251XFD_REG_OSC, osc,
303 				       !mcp251xfd_reg_invalid(osc) &&
304 				       (osc & osc_mask) == osc_reference,
305 				       MCP251XFD_OSC_STAB_SLEEP_US,
306 				       MCP251XFD_OSC_STAB_TIMEOUT_US);
307 	if (err != -ETIMEDOUT)
308 		return err;
309 
310 	if (mcp251xfd_reg_invalid(osc)) {
311 		netdev_err(priv->ndev,
312 			   "Failed to read Oscillator Configuration Register (osc=0x%08x).\n",
313 			   osc);
314 		return -ENODEV;
315 	}
316 
317 	netdev_err(priv->ndev,
318 		   "Timeout waiting for %s ready (osc=0x%08x, osc_reference=0x%08x, osc_mask=0x%08x).\n",
319 		   mcp251xfd_get_osc_str(osc, osc_reference),
320 		   osc, osc_reference, osc_mask);
321 
322 	return -ETIMEDOUT;
323 }
324 
325 static int mcp251xfd_chip_wake(const struct mcp251xfd_priv *priv)
326 {
327 	u32 osc, osc_reference, osc_mask;
328 	int err;
329 
330 	/* For normal sleep on MCP2517FD and MCP2518FD, clearing
331 	 * "Oscillator Disable" will wake the chip. For low power mode
332 	 * on MCP2518FD, asserting the chip select will wake the
333 	 * chip. Writing to the Oscillator register will wake it in
334 	 * both cases.
335 	 */
336 	osc = FIELD_PREP(MCP251XFD_REG_OSC_CLKODIV_MASK,
337 			 MCP251XFD_REG_OSC_CLKODIV_10);
338 
339 	/* We cannot check for the PLL ready bit (either set or
340 	 * unset), as the PLL might be enabled. This can happen if the
341 	 * system reboots, while the mcp251xfd stays powered.
342 	 */
343 	osc_reference = MCP251XFD_REG_OSC_OSCRDY;
344 	osc_mask = MCP251XFD_REG_OSC_OSCRDY;
345 
346 	/* If the controller is in Sleep Mode the following write only
347 	 * removes the "Oscillator Disable" bit and powers it up. All
348 	 * other bits are unaffected.
349 	 */
350 	err = regmap_write(priv->map_reg, MCP251XFD_REG_OSC, osc);
351 	if (err)
352 		return err;
353 
354 	/* Sometimes the PLL is stuck enabled, the controller never
355 	 * sets the OSC Ready bit, and we get an -ETIMEDOUT. Our
356 	 * caller takes care of retry.
357 	 */
358 	return mcp251xfd_chip_wait_for_osc_ready(priv, osc_reference, osc_mask);
359 }
360 
361 static inline int mcp251xfd_chip_sleep(const struct mcp251xfd_priv *priv)
362 {
363 	if (priv->pll_enable) {
364 		u32 osc;
365 		int err;
366 
367 		/* Turn off PLL */
368 		osc = FIELD_PREP(MCP251XFD_REG_OSC_CLKODIV_MASK,
369 				 MCP251XFD_REG_OSC_CLKODIV_10);
370 		err = regmap_write(priv->map_reg, MCP251XFD_REG_OSC, osc);
371 		if (err)
372 			netdev_err(priv->ndev,
373 				   "Failed to disable PLL.\n");
374 
375 		priv->spi->max_speed_hz = priv->spi_max_speed_hz_slow;
376 	}
377 
378 	return mcp251xfd_chip_set_mode(priv, MCP251XFD_REG_CON_MODE_SLEEP);
379 }
380 
381 static int mcp251xfd_chip_softreset_do(const struct mcp251xfd_priv *priv)
382 {
383 	const __be16 cmd = mcp251xfd_cmd_reset();
384 	int err;
385 
386 	/* The Set Mode and SPI Reset command only works if the
387 	 * controller is not in Sleep Mode.
388 	 */
389 	err = mcp251xfd_chip_wake(priv);
390 	if (err)
391 		return err;
392 
393 	err = mcp251xfd_chip_set_mode(priv, MCP251XFD_REG_CON_MODE_CONFIG);
394 	if (err)
395 		return err;
396 
397 	/* spi_write_then_read() works with non DMA-safe buffers */
398 	return spi_write_then_read(priv->spi, &cmd, sizeof(cmd), NULL, 0);
399 }
400 
401 static int mcp251xfd_chip_softreset_check(const struct mcp251xfd_priv *priv)
402 {
403 	u32 osc_reference, osc_mask;
404 	u8 mode;
405 	int err;
406 
407 	/* Check for reset defaults of OSC reg.
408 	 * This will take care of stabilization period.
409 	 */
410 	osc_reference = MCP251XFD_REG_OSC_OSCRDY |
411 		FIELD_PREP(MCP251XFD_REG_OSC_CLKODIV_MASK,
412 			   MCP251XFD_REG_OSC_CLKODIV_10);
413 	osc_mask = osc_reference | MCP251XFD_REG_OSC_PLLRDY;
414 	err = mcp251xfd_chip_wait_for_osc_ready(priv, osc_reference, osc_mask);
415 	if (err)
416 		return err;
417 
418 	err = mcp251xfd_chip_get_mode(priv, &mode);
419 	if (err)
420 		return err;
421 
422 	if (mode != MCP251XFD_REG_CON_MODE_CONFIG) {
423 		netdev_info(priv->ndev,
424 			    "Controller not in Config Mode after reset, but in %s Mode (%u).\n",
425 			    mcp251xfd_get_mode_str(mode), mode);
426 		return -ETIMEDOUT;
427 	}
428 
429 	return 0;
430 }
431 
432 static int mcp251xfd_chip_softreset(const struct mcp251xfd_priv *priv)
433 {
434 	int err, i;
435 
436 	for (i = 0; i < MCP251XFD_SOFTRESET_RETRIES_MAX; i++) {
437 		if (i)
438 			netdev_info(priv->ndev,
439 				    "Retrying to reset controller.\n");
440 
441 		err = mcp251xfd_chip_softreset_do(priv);
442 		if (err == -ETIMEDOUT)
443 			continue;
444 		if (err)
445 			return err;
446 
447 		err = mcp251xfd_chip_softreset_check(priv);
448 		if (err == -ETIMEDOUT)
449 			continue;
450 		if (err)
451 			return err;
452 
453 		return 0;
454 	}
455 
456 	return err;
457 }
458 
459 static int mcp251xfd_chip_clock_init(const struct mcp251xfd_priv *priv)
460 {
461 	u32 osc, osc_reference, osc_mask;
462 	int err;
463 
464 	/* Activate Low Power Mode on Oscillator Disable. This only
465 	 * works on the MCP2518FD. The MCP2517FD will go into normal
466 	 * Sleep Mode instead.
467 	 */
468 	osc = MCP251XFD_REG_OSC_LPMEN |
469 		FIELD_PREP(MCP251XFD_REG_OSC_CLKODIV_MASK,
470 			   MCP251XFD_REG_OSC_CLKODIV_10);
471 	osc_reference = MCP251XFD_REG_OSC_OSCRDY;
472 	osc_mask = MCP251XFD_REG_OSC_OSCRDY | MCP251XFD_REG_OSC_PLLRDY;
473 
474 	if (priv->pll_enable) {
475 		osc |= MCP251XFD_REG_OSC_PLLEN;
476 		osc_reference |= MCP251XFD_REG_OSC_PLLRDY;
477 	}
478 
479 	err = regmap_write(priv->map_reg, MCP251XFD_REG_OSC, osc);
480 	if (err)
481 		return err;
482 
483 	err = mcp251xfd_chip_wait_for_osc_ready(priv, osc_reference, osc_mask);
484 	if (err)
485 		return err;
486 
487 	priv->spi->max_speed_hz = priv->spi_max_speed_hz_fast;
488 
489 	return 0;
490 }
491 
492 static int mcp251xfd_chip_timestamp_init(const struct mcp251xfd_priv *priv)
493 {
494 	/* Set Time Base Counter Prescaler to 1.
495 	 *
496 	 * This means an overflow of the 32 bit Time Base Counter
497 	 * register at 40 MHz every 107 seconds.
498 	 */
499 	return regmap_write(priv->map_reg, MCP251XFD_REG_TSCON,
500 			    MCP251XFD_REG_TSCON_TBCEN);
501 }
502 
503 static int mcp251xfd_set_bittiming(const struct mcp251xfd_priv *priv)
504 {
505 	const struct can_bittiming *bt = &priv->can.bittiming;
506 	const struct can_bittiming *dbt = &priv->can.data_bittiming;
507 	u32 val = 0;
508 	s8 tdco;
509 	int err;
510 
511 	/* CAN Control Register
512 	 *
513 	 * - no transmit bandwidth sharing
514 	 * - config mode
515 	 * - disable transmit queue
516 	 * - store in transmit FIFO event
517 	 * - transition to restricted operation mode on system error
518 	 * - ESI is transmitted recessive when ESI of message is high or
519 	 *   CAN controller error passive
520 	 * - restricted retransmission attempts,
521 	 *   use TQXCON_TXAT and FIFOCON_TXAT
522 	 * - wake-up filter bits T11FILTER
523 	 * - use CAN bus line filter for wakeup
524 	 * - protocol exception is treated as a form error
525 	 * - Do not compare data bytes
526 	 */
527 	val = FIELD_PREP(MCP251XFD_REG_CON_REQOP_MASK,
528 			 MCP251XFD_REG_CON_MODE_CONFIG) |
529 		MCP251XFD_REG_CON_STEF |
530 		MCP251XFD_REG_CON_ESIGM |
531 		MCP251XFD_REG_CON_RTXAT |
532 		FIELD_PREP(MCP251XFD_REG_CON_WFT_MASK,
533 			   MCP251XFD_REG_CON_WFT_T11FILTER) |
534 		MCP251XFD_REG_CON_WAKFIL |
535 		MCP251XFD_REG_CON_PXEDIS;
536 
537 	if (!(priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO))
538 		val |= MCP251XFD_REG_CON_ISOCRCEN;
539 
540 	err = regmap_write(priv->map_reg, MCP251XFD_REG_CON, val);
541 	if (err)
542 		return err;
543 
544 	/* Nominal Bit Time */
545 	val = FIELD_PREP(MCP251XFD_REG_NBTCFG_BRP_MASK, bt->brp - 1) |
546 		FIELD_PREP(MCP251XFD_REG_NBTCFG_TSEG1_MASK,
547 			   bt->prop_seg + bt->phase_seg1 - 1) |
548 		FIELD_PREP(MCP251XFD_REG_NBTCFG_TSEG2_MASK,
549 			   bt->phase_seg2 - 1) |
550 		FIELD_PREP(MCP251XFD_REG_NBTCFG_SJW_MASK, bt->sjw - 1);
551 
552 	err = regmap_write(priv->map_reg, MCP251XFD_REG_NBTCFG, val);
553 	if (err)
554 		return err;
555 
556 	if (!(priv->can.ctrlmode & CAN_CTRLMODE_FD))
557 		return 0;
558 
559 	/* Data Bit Time */
560 	val = FIELD_PREP(MCP251XFD_REG_DBTCFG_BRP_MASK, dbt->brp - 1) |
561 		FIELD_PREP(MCP251XFD_REG_DBTCFG_TSEG1_MASK,
562 			   dbt->prop_seg + dbt->phase_seg1 - 1) |
563 		FIELD_PREP(MCP251XFD_REG_DBTCFG_TSEG2_MASK,
564 			   dbt->phase_seg2 - 1) |
565 		FIELD_PREP(MCP251XFD_REG_DBTCFG_SJW_MASK, dbt->sjw - 1);
566 
567 	err = regmap_write(priv->map_reg, MCP251XFD_REG_DBTCFG, val);
568 	if (err)
569 		return err;
570 
571 	/* Transmitter Delay Compensation */
572 	tdco = clamp_t(int, dbt->brp * (dbt->prop_seg + dbt->phase_seg1),
573 		       -64, 63);
574 	val = FIELD_PREP(MCP251XFD_REG_TDC_TDCMOD_MASK,
575 			 MCP251XFD_REG_TDC_TDCMOD_AUTO) |
576 		FIELD_PREP(MCP251XFD_REG_TDC_TDCO_MASK, tdco);
577 
578 	return regmap_write(priv->map_reg, MCP251XFD_REG_TDC, val);
579 }
580 
581 static int mcp251xfd_chip_rx_int_enable(const struct mcp251xfd_priv *priv)
582 {
583 	u32 val;
584 
585 	if (!priv->rx_int)
586 		return 0;
587 
588 	/* Configure GPIOs:
589 	 * - PIN0: GPIO Input
590 	 * - PIN1: GPIO Input/RX Interrupt
591 	 *
592 	 * PIN1 must be Input, otherwise there is a glitch on the
593 	 * rx-INT line. It happens between setting the PIN as output
594 	 * (in the first byte of the SPI transfer) and configuring the
595 	 * PIN as interrupt (in the last byte of the SPI transfer).
596 	 */
597 	val = MCP251XFD_REG_IOCON_PM0 | MCP251XFD_REG_IOCON_TRIS1 |
598 		MCP251XFD_REG_IOCON_TRIS0;
599 	return regmap_write(priv->map_reg, MCP251XFD_REG_IOCON, val);
600 }
601 
602 static int mcp251xfd_chip_rx_int_disable(const struct mcp251xfd_priv *priv)
603 {
604 	u32 val;
605 
606 	if (!priv->rx_int)
607 		return 0;
608 
609 	/* Configure GPIOs:
610 	 * - PIN0: GPIO Input
611 	 * - PIN1: GPIO Input
612 	 */
613 	val = MCP251XFD_REG_IOCON_PM1 | MCP251XFD_REG_IOCON_PM0 |
614 		MCP251XFD_REG_IOCON_TRIS1 | MCP251XFD_REG_IOCON_TRIS0;
615 	return regmap_write(priv->map_reg, MCP251XFD_REG_IOCON, val);
616 }
617 
618 static int mcp251xfd_chip_ecc_init(struct mcp251xfd_priv *priv)
619 {
620 	struct mcp251xfd_ecc *ecc = &priv->ecc;
621 	void *ram;
622 	u32 val = 0;
623 	int err;
624 
625 	ecc->ecc_stat = 0;
626 
627 	if (priv->devtype_data.quirks & MCP251XFD_QUIRK_ECC)
628 		val = MCP251XFD_REG_ECCCON_ECCEN;
629 
630 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_ECCCON,
631 				 MCP251XFD_REG_ECCCON_ECCEN, val);
632 	if (err)
633 		return err;
634 
635 	ram = kzalloc(MCP251XFD_RAM_SIZE, GFP_KERNEL);
636 	if (!ram)
637 		return -ENOMEM;
638 
639 	err = regmap_raw_write(priv->map_reg, MCP251XFD_RAM_START, ram,
640 			       MCP251XFD_RAM_SIZE);
641 	kfree(ram);
642 
643 	return err;
644 }
645 
646 static u8 mcp251xfd_get_normal_mode(const struct mcp251xfd_priv *priv)
647 {
648 	u8 mode;
649 
650 	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
651 		mode = MCP251XFD_REG_CON_MODE_INT_LOOPBACK;
652 	else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
653 		mode = MCP251XFD_REG_CON_MODE_LISTENONLY;
654 	else if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
655 		mode = MCP251XFD_REG_CON_MODE_MIXED;
656 	else
657 		mode = MCP251XFD_REG_CON_MODE_CAN2_0;
658 
659 	return mode;
660 }
661 
662 static int
663 __mcp251xfd_chip_set_normal_mode(const struct mcp251xfd_priv *priv,
664 				 bool nowait)
665 {
666 	u8 mode;
667 
668 	mode = mcp251xfd_get_normal_mode(priv);
669 
670 	return __mcp251xfd_chip_set_mode(priv, mode, nowait);
671 }
672 
673 static inline int
674 mcp251xfd_chip_set_normal_mode(const struct mcp251xfd_priv *priv)
675 {
676 	return __mcp251xfd_chip_set_normal_mode(priv, false);
677 }
678 
679 static inline int
680 mcp251xfd_chip_set_normal_mode_nowait(const struct mcp251xfd_priv *priv)
681 {
682 	return __mcp251xfd_chip_set_normal_mode(priv, true);
683 }
684 
685 static int mcp251xfd_chip_interrupts_enable(const struct mcp251xfd_priv *priv)
686 {
687 	u32 val;
688 	int err;
689 
690 	val = MCP251XFD_REG_CRC_FERRIE | MCP251XFD_REG_CRC_CRCERRIE;
691 	err = regmap_write(priv->map_reg, MCP251XFD_REG_CRC, val);
692 	if (err)
693 		return err;
694 
695 	val = MCP251XFD_REG_ECCCON_DEDIE | MCP251XFD_REG_ECCCON_SECIE;
696 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_ECCCON, val, val);
697 	if (err)
698 		return err;
699 
700 	val = MCP251XFD_REG_INT_CERRIE |
701 		MCP251XFD_REG_INT_SERRIE |
702 		MCP251XFD_REG_INT_RXOVIE |
703 		MCP251XFD_REG_INT_TXATIE |
704 		MCP251XFD_REG_INT_SPICRCIE |
705 		MCP251XFD_REG_INT_ECCIE |
706 		MCP251XFD_REG_INT_TEFIE |
707 		MCP251XFD_REG_INT_MODIE |
708 		MCP251XFD_REG_INT_RXIE;
709 
710 	if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
711 		val |= MCP251XFD_REG_INT_IVMIE;
712 
713 	return regmap_write(priv->map_reg, MCP251XFD_REG_INT, val);
714 }
715 
716 static int mcp251xfd_chip_interrupts_disable(const struct mcp251xfd_priv *priv)
717 {
718 	int err;
719 	u32 mask;
720 
721 	err = regmap_write(priv->map_reg, MCP251XFD_REG_INT, 0);
722 	if (err)
723 		return err;
724 
725 	mask = MCP251XFD_REG_ECCCON_DEDIE | MCP251XFD_REG_ECCCON_SECIE;
726 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_ECCCON,
727 				 mask, 0x0);
728 	if (err)
729 		return err;
730 
731 	return regmap_write(priv->map_reg, MCP251XFD_REG_CRC, 0);
732 }
733 
734 static void mcp251xfd_chip_stop(struct mcp251xfd_priv *priv,
735 				const enum can_state state)
736 {
737 	priv->can.state = state;
738 
739 	mcp251xfd_chip_interrupts_disable(priv);
740 	mcp251xfd_chip_rx_int_disable(priv);
741 	mcp251xfd_chip_sleep(priv);
742 }
743 
744 static int mcp251xfd_chip_start(struct mcp251xfd_priv *priv)
745 {
746 	int err;
747 
748 	err = mcp251xfd_chip_softreset(priv);
749 	if (err)
750 		goto out_chip_stop;
751 
752 	err = mcp251xfd_chip_clock_init(priv);
753 	if (err)
754 		goto out_chip_stop;
755 
756 	err = mcp251xfd_chip_timestamp_init(priv);
757 	if (err)
758 		goto out_chip_stop;
759 
760 	err = mcp251xfd_set_bittiming(priv);
761 	if (err)
762 		goto out_chip_stop;
763 
764 	err = mcp251xfd_chip_rx_int_enable(priv);
765 	if (err)
766 		goto out_chip_stop;
767 
768 	err = mcp251xfd_chip_ecc_init(priv);
769 	if (err)
770 		goto out_chip_stop;
771 
772 	err = mcp251xfd_ring_init(priv);
773 	if (err)
774 		goto out_chip_stop;
775 
776 	err = mcp251xfd_chip_fifo_init(priv);
777 	if (err)
778 		goto out_chip_stop;
779 
780 	priv->can.state = CAN_STATE_ERROR_ACTIVE;
781 
782 	err = mcp251xfd_chip_set_normal_mode(priv);
783 	if (err)
784 		goto out_chip_stop;
785 
786 	return 0;
787 
788  out_chip_stop:
789 	mcp251xfd_dump(priv);
790 	mcp251xfd_chip_stop(priv, CAN_STATE_STOPPED);
791 
792 	return err;
793 }
794 
795 static int mcp251xfd_set_mode(struct net_device *ndev, enum can_mode mode)
796 {
797 	struct mcp251xfd_priv *priv = netdev_priv(ndev);
798 	int err;
799 
800 	switch (mode) {
801 	case CAN_MODE_START:
802 		err = mcp251xfd_chip_start(priv);
803 		if (err)
804 			return err;
805 
806 		err = mcp251xfd_chip_interrupts_enable(priv);
807 		if (err) {
808 			mcp251xfd_chip_stop(priv, CAN_STATE_STOPPED);
809 			return err;
810 		}
811 
812 		netif_wake_queue(ndev);
813 		break;
814 
815 	default:
816 		return -EOPNOTSUPP;
817 	}
818 
819 	return 0;
820 }
821 
822 static int __mcp251xfd_get_berr_counter(const struct net_device *ndev,
823 					struct can_berr_counter *bec)
824 {
825 	const struct mcp251xfd_priv *priv = netdev_priv(ndev);
826 	u32 trec;
827 	int err;
828 
829 	err = regmap_read(priv->map_reg, MCP251XFD_REG_TREC, &trec);
830 	if (err)
831 		return err;
832 
833 	if (trec & MCP251XFD_REG_TREC_TXBO)
834 		bec->txerr = 256;
835 	else
836 		bec->txerr = FIELD_GET(MCP251XFD_REG_TREC_TEC_MASK, trec);
837 	bec->rxerr = FIELD_GET(MCP251XFD_REG_TREC_REC_MASK, trec);
838 
839 	return 0;
840 }
841 
842 static int mcp251xfd_get_berr_counter(const struct net_device *ndev,
843 				      struct can_berr_counter *bec)
844 {
845 	const struct mcp251xfd_priv *priv = netdev_priv(ndev);
846 
847 	/* Avoid waking up the controller if the interface is down */
848 	if (!(ndev->flags & IFF_UP))
849 		return 0;
850 
851 	/* The controller is powered down during Bus Off, use saved
852 	 * bec values.
853 	 */
854 	if (priv->can.state == CAN_STATE_BUS_OFF) {
855 		*bec = priv->bec;
856 		return 0;
857 	}
858 
859 	return __mcp251xfd_get_berr_counter(ndev, bec);
860 }
861 
862 static struct sk_buff *
863 mcp251xfd_alloc_can_err_skb(struct mcp251xfd_priv *priv,
864 			    struct can_frame **cf, u32 *timestamp)
865 {
866 	struct sk_buff *skb;
867 	int err;
868 
869 	err = mcp251xfd_get_timestamp(priv, timestamp);
870 	if (err)
871 		return NULL;
872 
873 	skb = alloc_can_err_skb(priv->ndev, cf);
874 	if (skb)
875 		mcp251xfd_skb_set_timestamp(priv, skb, *timestamp);
876 
877 	return skb;
878 }
879 
880 static int mcp251xfd_handle_rxovif(struct mcp251xfd_priv *priv)
881 {
882 	struct net_device_stats *stats = &priv->ndev->stats;
883 	struct mcp251xfd_rx_ring *ring;
884 	struct sk_buff *skb;
885 	struct can_frame *cf;
886 	u32 timestamp, rxovif;
887 	int err, i;
888 
889 	stats->rx_over_errors++;
890 	stats->rx_errors++;
891 
892 	err = regmap_read(priv->map_reg, MCP251XFD_REG_RXOVIF, &rxovif);
893 	if (err)
894 		return err;
895 
896 	mcp251xfd_for_each_rx_ring(priv, ring, i) {
897 		if (!(rxovif & BIT(ring->fifo_nr)))
898 			continue;
899 
900 		/* If SERRIF is active, there was a RX MAB overflow. */
901 		if (priv->regs_status.intf & MCP251XFD_REG_INT_SERRIF) {
902 			if (net_ratelimit())
903 				netdev_dbg(priv->ndev,
904 					   "RX-%d: MAB overflow detected.\n",
905 					   ring->nr);
906 		} else {
907 			if (net_ratelimit())
908 				netdev_dbg(priv->ndev,
909 					   "RX-%d: FIFO overflow.\n",
910 					   ring->nr);
911 		}
912 
913 		err = regmap_update_bits(priv->map_reg,
914 					 MCP251XFD_REG_FIFOSTA(ring->fifo_nr),
915 					 MCP251XFD_REG_FIFOSTA_RXOVIF,
916 					 0x0);
917 		if (err)
918 			return err;
919 	}
920 
921 	skb = mcp251xfd_alloc_can_err_skb(priv, &cf, &timestamp);
922 	if (!skb)
923 		return 0;
924 
925 	cf->can_id |= CAN_ERR_CRTL;
926 	cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
927 
928 	err = can_rx_offload_queue_timestamp(&priv->offload, skb, timestamp);
929 	if (err)
930 		stats->rx_fifo_errors++;
931 
932 	return 0;
933 }
934 
935 static int mcp251xfd_handle_txatif(struct mcp251xfd_priv *priv)
936 {
937 	netdev_info(priv->ndev, "%s\n", __func__);
938 
939 	return 0;
940 }
941 
942 static int mcp251xfd_handle_ivmif(struct mcp251xfd_priv *priv)
943 {
944 	struct net_device_stats *stats = &priv->ndev->stats;
945 	u32 bdiag1, timestamp;
946 	struct sk_buff *skb;
947 	struct can_frame *cf = NULL;
948 	int err;
949 
950 	err = mcp251xfd_get_timestamp(priv, &timestamp);
951 	if (err)
952 		return err;
953 
954 	err = regmap_read(priv->map_reg, MCP251XFD_REG_BDIAG1, &bdiag1);
955 	if (err)
956 		return err;
957 
958 	/* Write 0s to clear error bits, don't write 1s to non active
959 	 * bits, as they will be set.
960 	 */
961 	err = regmap_write(priv->map_reg, MCP251XFD_REG_BDIAG1, 0x0);
962 	if (err)
963 		return err;
964 
965 	priv->can.can_stats.bus_error++;
966 
967 	skb = alloc_can_err_skb(priv->ndev, &cf);
968 	if (cf)
969 		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
970 
971 	/* Controller misconfiguration */
972 	if (WARN_ON(bdiag1 & MCP251XFD_REG_BDIAG1_DLCMM))
973 		netdev_err(priv->ndev,
974 			   "recv'd DLC is larger than PLSIZE of FIFO element.");
975 
976 	/* RX errors */
977 	if (bdiag1 & (MCP251XFD_REG_BDIAG1_DCRCERR |
978 		      MCP251XFD_REG_BDIAG1_NCRCERR)) {
979 		netdev_dbg(priv->ndev, "CRC error\n");
980 
981 		stats->rx_errors++;
982 		if (cf)
983 			cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
984 	}
985 	if (bdiag1 & (MCP251XFD_REG_BDIAG1_DSTUFERR |
986 		      MCP251XFD_REG_BDIAG1_NSTUFERR)) {
987 		netdev_dbg(priv->ndev, "Stuff error\n");
988 
989 		stats->rx_errors++;
990 		if (cf)
991 			cf->data[2] |= CAN_ERR_PROT_STUFF;
992 	}
993 	if (bdiag1 & (MCP251XFD_REG_BDIAG1_DFORMERR |
994 		      MCP251XFD_REG_BDIAG1_NFORMERR)) {
995 		netdev_dbg(priv->ndev, "Format error\n");
996 
997 		stats->rx_errors++;
998 		if (cf)
999 			cf->data[2] |= CAN_ERR_PROT_FORM;
1000 	}
1001 
1002 	/* TX errors */
1003 	if (bdiag1 & MCP251XFD_REG_BDIAG1_NACKERR) {
1004 		netdev_dbg(priv->ndev, "NACK error\n");
1005 
1006 		stats->tx_errors++;
1007 		if (cf) {
1008 			cf->can_id |= CAN_ERR_ACK;
1009 			cf->data[2] |= CAN_ERR_PROT_TX;
1010 		}
1011 	}
1012 	if (bdiag1 & (MCP251XFD_REG_BDIAG1_DBIT1ERR |
1013 		      MCP251XFD_REG_BDIAG1_NBIT1ERR)) {
1014 		netdev_dbg(priv->ndev, "Bit1 error\n");
1015 
1016 		stats->tx_errors++;
1017 		if (cf)
1018 			cf->data[2] |= CAN_ERR_PROT_TX | CAN_ERR_PROT_BIT1;
1019 	}
1020 	if (bdiag1 & (MCP251XFD_REG_BDIAG1_DBIT0ERR |
1021 		      MCP251XFD_REG_BDIAG1_NBIT0ERR)) {
1022 		netdev_dbg(priv->ndev, "Bit0 error\n");
1023 
1024 		stats->tx_errors++;
1025 		if (cf)
1026 			cf->data[2] |= CAN_ERR_PROT_TX | CAN_ERR_PROT_BIT0;
1027 	}
1028 
1029 	if (!cf)
1030 		return 0;
1031 
1032 	mcp251xfd_skb_set_timestamp(priv, skb, timestamp);
1033 	err = can_rx_offload_queue_timestamp(&priv->offload, skb, timestamp);
1034 	if (err)
1035 		stats->rx_fifo_errors++;
1036 
1037 	return 0;
1038 }
1039 
1040 static int mcp251xfd_handle_cerrif(struct mcp251xfd_priv *priv)
1041 {
1042 	struct net_device_stats *stats = &priv->ndev->stats;
1043 	struct sk_buff *skb;
1044 	struct can_frame *cf = NULL;
1045 	enum can_state new_state, rx_state, tx_state;
1046 	u32 trec, timestamp;
1047 	int err;
1048 
1049 	err = regmap_read(priv->map_reg, MCP251XFD_REG_TREC, &trec);
1050 	if (err)
1051 		return err;
1052 
1053 	if (trec & MCP251XFD_REG_TREC_TXBO)
1054 		tx_state = CAN_STATE_BUS_OFF;
1055 	else if (trec & MCP251XFD_REG_TREC_TXBP)
1056 		tx_state = CAN_STATE_ERROR_PASSIVE;
1057 	else if (trec & MCP251XFD_REG_TREC_TXWARN)
1058 		tx_state = CAN_STATE_ERROR_WARNING;
1059 	else
1060 		tx_state = CAN_STATE_ERROR_ACTIVE;
1061 
1062 	if (trec & MCP251XFD_REG_TREC_RXBP)
1063 		rx_state = CAN_STATE_ERROR_PASSIVE;
1064 	else if (trec & MCP251XFD_REG_TREC_RXWARN)
1065 		rx_state = CAN_STATE_ERROR_WARNING;
1066 	else
1067 		rx_state = CAN_STATE_ERROR_ACTIVE;
1068 
1069 	new_state = max(tx_state, rx_state);
1070 	if (new_state == priv->can.state)
1071 		return 0;
1072 
1073 	/* The skb allocation might fail, but can_change_state()
1074 	 * handles cf == NULL.
1075 	 */
1076 	skb = mcp251xfd_alloc_can_err_skb(priv, &cf, &timestamp);
1077 	can_change_state(priv->ndev, cf, tx_state, rx_state);
1078 
1079 	if (new_state == CAN_STATE_BUS_OFF) {
1080 		/* As we're going to switch off the chip now, let's
1081 		 * save the error counters and return them to
1082 		 * userspace, if do_get_berr_counter() is called while
1083 		 * the chip is in Bus Off.
1084 		 */
1085 		err = __mcp251xfd_get_berr_counter(priv->ndev, &priv->bec);
1086 		if (err)
1087 			return err;
1088 
1089 		mcp251xfd_chip_stop(priv, CAN_STATE_BUS_OFF);
1090 		can_bus_off(priv->ndev);
1091 	}
1092 
1093 	if (!skb)
1094 		return 0;
1095 
1096 	if (new_state != CAN_STATE_BUS_OFF) {
1097 		struct can_berr_counter bec;
1098 
1099 		err = mcp251xfd_get_berr_counter(priv->ndev, &bec);
1100 		if (err)
1101 			return err;
1102 		cf->can_id |= CAN_ERR_CNT;
1103 		cf->data[6] = bec.txerr;
1104 		cf->data[7] = bec.rxerr;
1105 	}
1106 
1107 	err = can_rx_offload_queue_timestamp(&priv->offload, skb, timestamp);
1108 	if (err)
1109 		stats->rx_fifo_errors++;
1110 
1111 	return 0;
1112 }
1113 
1114 static int
1115 mcp251xfd_handle_modif(const struct mcp251xfd_priv *priv, bool *set_normal_mode)
1116 {
1117 	const u8 mode_reference = mcp251xfd_get_normal_mode(priv);
1118 	u8 mode;
1119 	int err;
1120 
1121 	err = mcp251xfd_chip_get_mode(priv, &mode);
1122 	if (err)
1123 		return err;
1124 
1125 	if (mode == mode_reference) {
1126 		netdev_dbg(priv->ndev,
1127 			   "Controller changed into %s Mode (%u).\n",
1128 			   mcp251xfd_get_mode_str(mode), mode);
1129 		return 0;
1130 	}
1131 
1132 	/* According to MCP2517FD errata DS80000792B 1., during a TX
1133 	 * MAB underflow, the controller will transition to Restricted
1134 	 * Operation Mode or Listen Only Mode (depending on SERR2LOM).
1135 	 *
1136 	 * However this is not always the case. If SERR2LOM is
1137 	 * configured for Restricted Operation Mode (SERR2LOM not set)
1138 	 * the MCP2517FD will sometimes transition to Listen Only Mode
1139 	 * first. When polling this bit we see that it will transition
1140 	 * to Restricted Operation Mode shortly after.
1141 	 */
1142 	if ((priv->devtype_data.quirks & MCP251XFD_QUIRK_MAB_NO_WARN) &&
1143 	    (mode == MCP251XFD_REG_CON_MODE_RESTRICTED ||
1144 	     mode == MCP251XFD_REG_CON_MODE_LISTENONLY))
1145 		netdev_dbg(priv->ndev,
1146 			   "Controller changed into %s Mode (%u).\n",
1147 			   mcp251xfd_get_mode_str(mode), mode);
1148 	else
1149 		netdev_err(priv->ndev,
1150 			   "Controller changed into %s Mode (%u).\n",
1151 			   mcp251xfd_get_mode_str(mode), mode);
1152 
1153 	/* After the application requests Normal mode, the controller
1154 	 * will automatically attempt to retransmit the message that
1155 	 * caused the TX MAB underflow.
1156 	 *
1157 	 * However, if there is an ECC error in the TX-RAM, we first
1158 	 * have to reload the tx-object before requesting Normal
1159 	 * mode. This is done later in mcp251xfd_handle_eccif().
1160 	 */
1161 	if (priv->regs_status.intf & MCP251XFD_REG_INT_ECCIF) {
1162 		*set_normal_mode = true;
1163 		return 0;
1164 	}
1165 
1166 	return mcp251xfd_chip_set_normal_mode_nowait(priv);
1167 }
1168 
1169 static int mcp251xfd_handle_serrif(struct mcp251xfd_priv *priv)
1170 {
1171 	struct mcp251xfd_ecc *ecc = &priv->ecc;
1172 	struct net_device_stats *stats = &priv->ndev->stats;
1173 	bool handled = false;
1174 
1175 	/* TX MAB underflow
1176 	 *
1177 	 * According to MCP2517FD Errata DS80000792B 1. a TX MAB
1178 	 * underflow is indicated by SERRIF and MODIF.
1179 	 *
1180 	 * In addition to the effects mentioned in the Errata, there
1181 	 * are Bus Errors due to the aborted CAN frame, so a IVMIF
1182 	 * will be seen as well.
1183 	 *
1184 	 * Sometimes there is an ECC error in the TX-RAM, which leads
1185 	 * to a TX MAB underflow.
1186 	 *
1187 	 * However, probably due to a race condition, there is no
1188 	 * associated MODIF pending.
1189 	 *
1190 	 * Further, there are situations, where the SERRIF is caused
1191 	 * by an ECC error in the TX-RAM, but not even the ECCIF is
1192 	 * set. This only seems to happen _after_ the first occurrence
1193 	 * of a ECCIF (which is tracked in ecc->cnt).
1194 	 *
1195 	 * Treat all as a known system errors..
1196 	 */
1197 	if ((priv->regs_status.intf & MCP251XFD_REG_INT_MODIF &&
1198 	     priv->regs_status.intf & MCP251XFD_REG_INT_IVMIF) ||
1199 	    priv->regs_status.intf & MCP251XFD_REG_INT_ECCIF ||
1200 	    ecc->cnt) {
1201 		const char *msg;
1202 
1203 		if (priv->regs_status.intf & MCP251XFD_REG_INT_ECCIF ||
1204 		    ecc->cnt)
1205 			msg = "TX MAB underflow due to ECC error detected.";
1206 		else
1207 			msg = "TX MAB underflow detected.";
1208 
1209 		if (priv->devtype_data.quirks & MCP251XFD_QUIRK_MAB_NO_WARN)
1210 			netdev_dbg(priv->ndev, "%s\n", msg);
1211 		else
1212 			netdev_info(priv->ndev, "%s\n", msg);
1213 
1214 		stats->tx_aborted_errors++;
1215 		stats->tx_errors++;
1216 		handled = true;
1217 	}
1218 
1219 	/* RX MAB overflow
1220 	 *
1221 	 * According to MCP2517FD Errata DS80000792B 1. a RX MAB
1222 	 * overflow is indicated by SERRIF.
1223 	 *
1224 	 * In addition to the effects mentioned in the Errata, (most
1225 	 * of the times) a RXOVIF is raised, if the FIFO that is being
1226 	 * received into has the RXOVIE activated (and we have enabled
1227 	 * RXOVIE on all FIFOs).
1228 	 *
1229 	 * Sometimes there is no RXOVIF just a RXIF is pending.
1230 	 *
1231 	 * Treat all as a known system errors..
1232 	 */
1233 	if (priv->regs_status.intf & MCP251XFD_REG_INT_RXOVIF ||
1234 	    priv->regs_status.intf & MCP251XFD_REG_INT_RXIF) {
1235 		stats->rx_dropped++;
1236 		handled = true;
1237 	}
1238 
1239 	if (!handled)
1240 		netdev_err(priv->ndev,
1241 			   "Unhandled System Error Interrupt (intf=0x%08x)!\n",
1242 			   priv->regs_status.intf);
1243 
1244 	return 0;
1245 }
1246 
1247 static int
1248 mcp251xfd_handle_eccif_recover(struct mcp251xfd_priv *priv, u8 nr)
1249 {
1250 	struct mcp251xfd_tx_ring *tx_ring = priv->tx;
1251 	struct mcp251xfd_ecc *ecc = &priv->ecc;
1252 	struct mcp251xfd_tx_obj *tx_obj;
1253 	u8 chip_tx_tail, tx_tail, offset;
1254 	u16 addr;
1255 	int err;
1256 
1257 	addr = FIELD_GET(MCP251XFD_REG_ECCSTAT_ERRADDR_MASK, ecc->ecc_stat);
1258 
1259 	err = mcp251xfd_tx_tail_get_from_chip(priv, &chip_tx_tail);
1260 	if (err)
1261 		return err;
1262 
1263 	tx_tail = mcp251xfd_get_tx_tail(tx_ring);
1264 	offset = (nr - chip_tx_tail) & (tx_ring->obj_num - 1);
1265 
1266 	/* Bail out if one of the following is met:
1267 	 * - tx_tail information is inconsistent
1268 	 * - for mcp2517fd: offset not 0
1269 	 * - for mcp2518fd: offset not 0 or 1
1270 	 */
1271 	if (chip_tx_tail != tx_tail ||
1272 	    !(offset == 0 || (offset == 1 && (mcp251xfd_is_2518FD(priv) ||
1273 					      mcp251xfd_is_251863(priv))))) {
1274 		netdev_err(priv->ndev,
1275 			   "ECC Error information inconsistent (addr=0x%04x, nr=%d, tx_tail=0x%08x(%d), chip_tx_tail=%d, offset=%d).\n",
1276 			   addr, nr, tx_ring->tail, tx_tail, chip_tx_tail,
1277 			   offset);
1278 		return -EINVAL;
1279 	}
1280 
1281 	netdev_info(priv->ndev,
1282 		    "Recovering %s ECC Error at address 0x%04x (in TX-RAM, tx_obj=%d, tx_tail=0x%08x(%d), offset=%d).\n",
1283 		    ecc->ecc_stat & MCP251XFD_REG_ECCSTAT_SECIF ?
1284 		    "Single" : "Double",
1285 		    addr, nr, tx_ring->tail, tx_tail, offset);
1286 
1287 	/* reload tx_obj into controller RAM ... */
1288 	tx_obj = &tx_ring->obj[nr];
1289 	err = spi_sync_transfer(priv->spi, tx_obj->xfer, 1);
1290 	if (err)
1291 		return err;
1292 
1293 	/* ... and trigger retransmit */
1294 	return mcp251xfd_chip_set_normal_mode(priv);
1295 }
1296 
1297 static int
1298 mcp251xfd_handle_eccif(struct mcp251xfd_priv *priv, bool set_normal_mode)
1299 {
1300 	struct mcp251xfd_ecc *ecc = &priv->ecc;
1301 	const char *msg;
1302 	bool in_tx_ram;
1303 	u32 ecc_stat;
1304 	u16 addr;
1305 	u8 nr;
1306 	int err;
1307 
1308 	err = regmap_read(priv->map_reg, MCP251XFD_REG_ECCSTAT, &ecc_stat);
1309 	if (err)
1310 		return err;
1311 
1312 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_ECCSTAT,
1313 				 MCP251XFD_REG_ECCSTAT_IF_MASK, ~ecc_stat);
1314 	if (err)
1315 		return err;
1316 
1317 	/* Check if ECC error occurred in TX-RAM */
1318 	addr = FIELD_GET(MCP251XFD_REG_ECCSTAT_ERRADDR_MASK, ecc_stat);
1319 	err = mcp251xfd_get_tx_nr_by_addr(priv->tx, &nr, addr);
1320 	if (!err)
1321 		in_tx_ram = true;
1322 	else if (err == -ENOENT)
1323 		in_tx_ram = false;
1324 	else
1325 		return err;
1326 
1327 	/* Errata Reference:
1328 	 * mcp2517fd: DS80000789B, mcp2518fd: DS80000792C 2.
1329 	 *
1330 	 * ECC single error correction does not work in all cases:
1331 	 *
1332 	 * Fix/Work Around:
1333 	 * Enable single error correction and double error detection
1334 	 * interrupts by setting SECIE and DEDIE. Handle SECIF as a
1335 	 * detection interrupt and do not rely on the error
1336 	 * correction. Instead, handle both interrupts as a
1337 	 * notification that the RAM word at ERRADDR was corrupted.
1338 	 */
1339 	if (ecc_stat & MCP251XFD_REG_ECCSTAT_SECIF)
1340 		msg = "Single ECC Error detected at address";
1341 	else if (ecc_stat & MCP251XFD_REG_ECCSTAT_DEDIF)
1342 		msg = "Double ECC Error detected at address";
1343 	else
1344 		return -EINVAL;
1345 
1346 	if (!in_tx_ram) {
1347 		ecc->ecc_stat = 0;
1348 
1349 		netdev_notice(priv->ndev, "%s 0x%04x.\n", msg, addr);
1350 	} else {
1351 		/* Re-occurring error? */
1352 		if (ecc->ecc_stat == ecc_stat) {
1353 			ecc->cnt++;
1354 		} else {
1355 			ecc->ecc_stat = ecc_stat;
1356 			ecc->cnt = 1;
1357 		}
1358 
1359 		netdev_info(priv->ndev,
1360 			    "%s 0x%04x (in TX-RAM, tx_obj=%d), occurred %d time%s.\n",
1361 			    msg, addr, nr, ecc->cnt, ecc->cnt > 1 ? "s" : "");
1362 
1363 		if (ecc->cnt >= MCP251XFD_ECC_CNT_MAX)
1364 			return mcp251xfd_handle_eccif_recover(priv, nr);
1365 	}
1366 
1367 	if (set_normal_mode)
1368 		return mcp251xfd_chip_set_normal_mode_nowait(priv);
1369 
1370 	return 0;
1371 }
1372 
1373 static int mcp251xfd_handle_spicrcif(struct mcp251xfd_priv *priv)
1374 {
1375 	int err;
1376 	u32 crc;
1377 
1378 	err = regmap_read(priv->map_reg, MCP251XFD_REG_CRC, &crc);
1379 	if (err)
1380 		return err;
1381 
1382 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_CRC,
1383 				 MCP251XFD_REG_CRC_IF_MASK,
1384 				 ~crc);
1385 	if (err)
1386 		return err;
1387 
1388 	if (crc & MCP251XFD_REG_CRC_FERRIF)
1389 		netdev_notice(priv->ndev, "CRC write command format error.\n");
1390 	else if (crc & MCP251XFD_REG_CRC_CRCERRIF)
1391 		netdev_notice(priv->ndev,
1392 			      "CRC write error detected. CRC=0x%04lx.\n",
1393 			      FIELD_GET(MCP251XFD_REG_CRC_MASK, crc));
1394 
1395 	return 0;
1396 }
1397 
1398 static int mcp251xfd_read_regs_status(struct mcp251xfd_priv *priv)
1399 {
1400 	const int val_bytes = regmap_get_val_bytes(priv->map_reg);
1401 	size_t len;
1402 
1403 	if (priv->rx_ring_num == 1)
1404 		len = sizeof(priv->regs_status.intf);
1405 	else
1406 		len = sizeof(priv->regs_status);
1407 
1408 	return regmap_bulk_read(priv->map_reg, MCP251XFD_REG_INT,
1409 				&priv->regs_status, len / val_bytes);
1410 }
1411 
1412 #define mcp251xfd_handle(priv, irq, ...) \
1413 ({ \
1414 	struct mcp251xfd_priv *_priv = (priv); \
1415 	int err; \
1416 \
1417 	err = mcp251xfd_handle_##irq(_priv, ## __VA_ARGS__); \
1418 	if (err) \
1419 		netdev_err(_priv->ndev, \
1420 			"IRQ handler mcp251xfd_handle_%s() returned %d.\n", \
1421 			__stringify(irq), err); \
1422 	err; \
1423 })
1424 
1425 static irqreturn_t mcp251xfd_irq(int irq, void *dev_id)
1426 {
1427 	struct mcp251xfd_priv *priv = dev_id;
1428 	irqreturn_t handled = IRQ_NONE;
1429 	int err;
1430 
1431 	if (priv->rx_int)
1432 		do {
1433 			int rx_pending;
1434 
1435 			rx_pending = gpiod_get_value_cansleep(priv->rx_int);
1436 			if (!rx_pending)
1437 				break;
1438 
1439 			/* Assume 1st RX-FIFO pending, if other FIFOs
1440 			 * are pending the main IRQ handler will take
1441 			 * care.
1442 			 */
1443 			priv->regs_status.rxif = BIT(priv->rx[0]->fifo_nr);
1444 			err = mcp251xfd_handle(priv, rxif);
1445 			if (err)
1446 				goto out_fail;
1447 
1448 			handled = IRQ_HANDLED;
1449 
1450 			/* We don't know which RX-FIFO is pending, but only
1451 			 * handle the 1st RX-FIFO. Leave loop here if we have
1452 			 * more than 1 RX-FIFO to avoid starvation.
1453 			 */
1454 		} while (priv->rx_ring_num == 1);
1455 
1456 	do {
1457 		u32 intf_pending, intf_pending_clearable;
1458 		bool set_normal_mode = false;
1459 
1460 		err = mcp251xfd_read_regs_status(priv);
1461 		if (err)
1462 			goto out_fail;
1463 
1464 		intf_pending = FIELD_GET(MCP251XFD_REG_INT_IF_MASK,
1465 					 priv->regs_status.intf) &
1466 			FIELD_GET(MCP251XFD_REG_INT_IE_MASK,
1467 				  priv->regs_status.intf);
1468 
1469 		if (!(intf_pending)) {
1470 			can_rx_offload_threaded_irq_finish(&priv->offload);
1471 			return handled;
1472 		}
1473 
1474 		/* Some interrupts must be ACKed in the
1475 		 * MCP251XFD_REG_INT register.
1476 		 * - First ACK then handle, to avoid lost-IRQ race
1477 		 *   condition on fast re-occurring interrupts.
1478 		 * - Write "0" to clear active IRQs, "1" to all other,
1479 		 *   to avoid r/m/w race condition on the
1480 		 *   MCP251XFD_REG_INT register.
1481 		 */
1482 		intf_pending_clearable = intf_pending &
1483 			MCP251XFD_REG_INT_IF_CLEARABLE_MASK;
1484 		if (intf_pending_clearable) {
1485 			err = regmap_update_bits(priv->map_reg,
1486 						 MCP251XFD_REG_INT,
1487 						 MCP251XFD_REG_INT_IF_MASK,
1488 						 ~intf_pending_clearable);
1489 			if (err)
1490 				goto out_fail;
1491 		}
1492 
1493 		if (intf_pending & MCP251XFD_REG_INT_MODIF) {
1494 			err = mcp251xfd_handle(priv, modif, &set_normal_mode);
1495 			if (err)
1496 				goto out_fail;
1497 		}
1498 
1499 		if (intf_pending & MCP251XFD_REG_INT_RXIF) {
1500 			err = mcp251xfd_handle(priv, rxif);
1501 			if (err)
1502 				goto out_fail;
1503 		}
1504 
1505 		if (intf_pending & MCP251XFD_REG_INT_TEFIF) {
1506 			err = mcp251xfd_handle(priv, tefif);
1507 			if (err)
1508 				goto out_fail;
1509 		}
1510 
1511 		if (intf_pending & MCP251XFD_REG_INT_RXOVIF) {
1512 			err = mcp251xfd_handle(priv, rxovif);
1513 			if (err)
1514 				goto out_fail;
1515 		}
1516 
1517 		if (intf_pending & MCP251XFD_REG_INT_TXATIF) {
1518 			err = mcp251xfd_handle(priv, txatif);
1519 			if (err)
1520 				goto out_fail;
1521 		}
1522 
1523 		if (intf_pending & MCP251XFD_REG_INT_IVMIF) {
1524 			err = mcp251xfd_handle(priv, ivmif);
1525 			if (err)
1526 				goto out_fail;
1527 		}
1528 
1529 		if (intf_pending & MCP251XFD_REG_INT_SERRIF) {
1530 			err = mcp251xfd_handle(priv, serrif);
1531 			if (err)
1532 				goto out_fail;
1533 		}
1534 
1535 		if (intf_pending & MCP251XFD_REG_INT_ECCIF) {
1536 			err = mcp251xfd_handle(priv, eccif, set_normal_mode);
1537 			if (err)
1538 				goto out_fail;
1539 		}
1540 
1541 		if (intf_pending & MCP251XFD_REG_INT_SPICRCIF) {
1542 			err = mcp251xfd_handle(priv, spicrcif);
1543 			if (err)
1544 				goto out_fail;
1545 		}
1546 
1547 		/* On the MCP2527FD and MCP2518FD, we don't get a
1548 		 * CERRIF IRQ on the transition TX ERROR_WARNING -> TX
1549 		 * ERROR_ACTIVE.
1550 		 */
1551 		if (intf_pending & MCP251XFD_REG_INT_CERRIF ||
1552 		    priv->can.state > CAN_STATE_ERROR_ACTIVE) {
1553 			err = mcp251xfd_handle(priv, cerrif);
1554 			if (err)
1555 				goto out_fail;
1556 
1557 			/* In Bus Off we completely shut down the
1558 			 * controller. Every subsequent register read
1559 			 * will read bogus data, and if
1560 			 * MCP251XFD_QUIRK_CRC_REG is enabled the CRC
1561 			 * check will fail, too. So leave IRQ handler
1562 			 * directly.
1563 			 */
1564 			if (priv->can.state == CAN_STATE_BUS_OFF) {
1565 				can_rx_offload_threaded_irq_finish(&priv->offload);
1566 				return IRQ_HANDLED;
1567 			}
1568 		}
1569 
1570 		handled = IRQ_HANDLED;
1571 	} while (1);
1572 
1573  out_fail:
1574 	can_rx_offload_threaded_irq_finish(&priv->offload);
1575 
1576 	netdev_err(priv->ndev, "IRQ handler returned %d (intf=0x%08x).\n",
1577 		   err, priv->regs_status.intf);
1578 	mcp251xfd_dump(priv);
1579 	mcp251xfd_chip_interrupts_disable(priv);
1580 	mcp251xfd_timestamp_stop(priv);
1581 
1582 	return handled;
1583 }
1584 
1585 static int mcp251xfd_open(struct net_device *ndev)
1586 {
1587 	struct mcp251xfd_priv *priv = netdev_priv(ndev);
1588 	const struct spi_device *spi = priv->spi;
1589 	int err;
1590 
1591 	err = open_candev(ndev);
1592 	if (err)
1593 		return err;
1594 
1595 	err = pm_runtime_resume_and_get(ndev->dev.parent);
1596 	if (err)
1597 		goto out_close_candev;
1598 
1599 	err = mcp251xfd_ring_alloc(priv);
1600 	if (err)
1601 		goto out_pm_runtime_put;
1602 
1603 	err = mcp251xfd_transceiver_enable(priv);
1604 	if (err)
1605 		goto out_mcp251xfd_ring_free;
1606 
1607 	err = mcp251xfd_chip_start(priv);
1608 	if (err)
1609 		goto out_transceiver_disable;
1610 
1611 	mcp251xfd_timestamp_init(priv);
1612 	clear_bit(MCP251XFD_FLAGS_DOWN, priv->flags);
1613 	can_rx_offload_enable(&priv->offload);
1614 
1615 	err = request_threaded_irq(spi->irq, NULL, mcp251xfd_irq,
1616 				   IRQF_SHARED | IRQF_ONESHOT,
1617 				   dev_name(&spi->dev), priv);
1618 	if (err)
1619 		goto out_can_rx_offload_disable;
1620 
1621 	err = mcp251xfd_chip_interrupts_enable(priv);
1622 	if (err)
1623 		goto out_free_irq;
1624 
1625 	netif_start_queue(ndev);
1626 
1627 	return 0;
1628 
1629  out_free_irq:
1630 	free_irq(spi->irq, priv);
1631  out_can_rx_offload_disable:
1632 	can_rx_offload_disable(&priv->offload);
1633 	set_bit(MCP251XFD_FLAGS_DOWN, priv->flags);
1634 	mcp251xfd_timestamp_stop(priv);
1635  out_transceiver_disable:
1636 	mcp251xfd_transceiver_disable(priv);
1637  out_mcp251xfd_ring_free:
1638 	mcp251xfd_ring_free(priv);
1639  out_pm_runtime_put:
1640 	mcp251xfd_chip_stop(priv, CAN_STATE_STOPPED);
1641 	pm_runtime_put(ndev->dev.parent);
1642  out_close_candev:
1643 	close_candev(ndev);
1644 
1645 	return err;
1646 }
1647 
1648 static int mcp251xfd_stop(struct net_device *ndev)
1649 {
1650 	struct mcp251xfd_priv *priv = netdev_priv(ndev);
1651 
1652 	netif_stop_queue(ndev);
1653 	set_bit(MCP251XFD_FLAGS_DOWN, priv->flags);
1654 	hrtimer_cancel(&priv->rx_irq_timer);
1655 	hrtimer_cancel(&priv->tx_irq_timer);
1656 	mcp251xfd_chip_interrupts_disable(priv);
1657 	free_irq(ndev->irq, priv);
1658 	can_rx_offload_disable(&priv->offload);
1659 	mcp251xfd_timestamp_stop(priv);
1660 	mcp251xfd_chip_stop(priv, CAN_STATE_STOPPED);
1661 	mcp251xfd_transceiver_disable(priv);
1662 	mcp251xfd_ring_free(priv);
1663 	close_candev(ndev);
1664 
1665 	pm_runtime_put(ndev->dev.parent);
1666 
1667 	return 0;
1668 }
1669 
1670 static const struct net_device_ops mcp251xfd_netdev_ops = {
1671 	.ndo_open = mcp251xfd_open,
1672 	.ndo_stop = mcp251xfd_stop,
1673 	.ndo_start_xmit	= mcp251xfd_start_xmit,
1674 	.ndo_eth_ioctl = can_eth_ioctl_hwts,
1675 	.ndo_change_mtu = can_change_mtu,
1676 };
1677 
1678 static void
1679 mcp251xfd_register_quirks(struct mcp251xfd_priv *priv)
1680 {
1681 	const struct spi_device *spi = priv->spi;
1682 	const struct spi_controller *ctlr = spi->controller;
1683 
1684 	if (ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX)
1685 		priv->devtype_data.quirks |= MCP251XFD_QUIRK_HALF_DUPLEX;
1686 }
1687 
1688 static int mcp251xfd_register_chip_detect(struct mcp251xfd_priv *priv)
1689 {
1690 	const struct net_device *ndev = priv->ndev;
1691 	const struct mcp251xfd_devtype_data *devtype_data;
1692 	u32 osc;
1693 	int err;
1694 
1695 	/* The OSC_LPMEN is only supported on MCP2518FD and MCP251863,
1696 	 * so use it to autodetect the model.
1697 	 */
1698 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_OSC,
1699 				 MCP251XFD_REG_OSC_LPMEN,
1700 				 MCP251XFD_REG_OSC_LPMEN);
1701 	if (err)
1702 		return err;
1703 
1704 	err = regmap_read(priv->map_reg, MCP251XFD_REG_OSC, &osc);
1705 	if (err)
1706 		return err;
1707 
1708 	if (osc & MCP251XFD_REG_OSC_LPMEN) {
1709 		/* We cannot distinguish between MCP2518FD and
1710 		 * MCP251863. If firmware specifies MCP251863, keep
1711 		 * it, otherwise set to MCP2518FD.
1712 		 */
1713 		if (mcp251xfd_is_251863(priv))
1714 			devtype_data = &mcp251xfd_devtype_data_mcp251863;
1715 		else
1716 			devtype_data = &mcp251xfd_devtype_data_mcp2518fd;
1717 	} else {
1718 		devtype_data = &mcp251xfd_devtype_data_mcp2517fd;
1719 	}
1720 
1721 	if (!mcp251xfd_is_251XFD(priv) &&
1722 	    priv->devtype_data.model != devtype_data->model) {
1723 		netdev_info(ndev,
1724 			    "Detected %s, but firmware specifies a %s. Fixing up.\n",
1725 			    __mcp251xfd_get_model_str(devtype_data->model),
1726 			    mcp251xfd_get_model_str(priv));
1727 	}
1728 	priv->devtype_data = *devtype_data;
1729 
1730 	/* We need to preserve the Half Duplex Quirk. */
1731 	mcp251xfd_register_quirks(priv);
1732 
1733 	/* Re-init regmap with quirks of detected model. */
1734 	return mcp251xfd_regmap_init(priv);
1735 }
1736 
1737 static int mcp251xfd_register_check_rx_int(struct mcp251xfd_priv *priv)
1738 {
1739 	int err, rx_pending;
1740 
1741 	if (!priv->rx_int)
1742 		return 0;
1743 
1744 	err = mcp251xfd_chip_rx_int_enable(priv);
1745 	if (err)
1746 		return err;
1747 
1748 	/* Check if RX_INT is properly working. The RX_INT should not
1749 	 * be active after a softreset.
1750 	 */
1751 	rx_pending = gpiod_get_value_cansleep(priv->rx_int);
1752 
1753 	err = mcp251xfd_chip_rx_int_disable(priv);
1754 	if (err)
1755 		return err;
1756 
1757 	if (!rx_pending)
1758 		return 0;
1759 
1760 	netdev_info(priv->ndev,
1761 		    "RX_INT active after softreset, disabling RX_INT support.\n");
1762 	devm_gpiod_put(&priv->spi->dev, priv->rx_int);
1763 	priv->rx_int = NULL;
1764 
1765 	return 0;
1766 }
1767 
1768 static int
1769 mcp251xfd_register_get_dev_id(const struct mcp251xfd_priv *priv, u32 *dev_id,
1770 			      u32 *effective_speed_hz_slow,
1771 			      u32 *effective_speed_hz_fast)
1772 {
1773 	struct mcp251xfd_map_buf_nocrc *buf_rx;
1774 	struct mcp251xfd_map_buf_nocrc *buf_tx;
1775 	struct spi_transfer xfer[2] = { };
1776 	int err;
1777 
1778 	buf_rx = kzalloc(sizeof(*buf_rx), GFP_KERNEL);
1779 	if (!buf_rx)
1780 		return -ENOMEM;
1781 
1782 	buf_tx = kzalloc(sizeof(*buf_tx), GFP_KERNEL);
1783 	if (!buf_tx) {
1784 		err = -ENOMEM;
1785 		goto out_kfree_buf_rx;
1786 	}
1787 
1788 	xfer[0].tx_buf = buf_tx;
1789 	xfer[0].len = sizeof(buf_tx->cmd);
1790 	xfer[0].speed_hz = priv->spi_max_speed_hz_slow;
1791 	xfer[1].rx_buf = buf_rx->data;
1792 	xfer[1].len = sizeof(*dev_id);
1793 	xfer[1].speed_hz = priv->spi_max_speed_hz_fast;
1794 
1795 	mcp251xfd_spi_cmd_read_nocrc(&buf_tx->cmd, MCP251XFD_REG_DEVID);
1796 
1797 	err = spi_sync_transfer(priv->spi, xfer, ARRAY_SIZE(xfer));
1798 	if (err)
1799 		goto out_kfree_buf_tx;
1800 
1801 	*dev_id = get_unaligned_le32(buf_rx->data);
1802 	*effective_speed_hz_slow = xfer[0].effective_speed_hz;
1803 	*effective_speed_hz_fast = xfer[1].effective_speed_hz;
1804 
1805  out_kfree_buf_tx:
1806 	kfree(buf_tx);
1807  out_kfree_buf_rx:
1808 	kfree(buf_rx);
1809 
1810 	return err;
1811 }
1812 
1813 #define MCP251XFD_QUIRK_ACTIVE(quirk) \
1814 	(priv->devtype_data.quirks & MCP251XFD_QUIRK_##quirk ? '+' : '-')
1815 
1816 static int
1817 mcp251xfd_register_done(const struct mcp251xfd_priv *priv)
1818 {
1819 	u32 dev_id, effective_speed_hz_slow, effective_speed_hz_fast;
1820 	unsigned long clk_rate;
1821 	int err;
1822 
1823 	err = mcp251xfd_register_get_dev_id(priv, &dev_id,
1824 					    &effective_speed_hz_slow,
1825 					    &effective_speed_hz_fast);
1826 	if (err)
1827 		return err;
1828 
1829 	clk_rate = clk_get_rate(priv->clk);
1830 
1831 	netdev_info(priv->ndev,
1832 		    "%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",
1833 		    mcp251xfd_get_model_str(priv),
1834 		    FIELD_GET(MCP251XFD_REG_DEVID_ID_MASK, dev_id),
1835 		    FIELD_GET(MCP251XFD_REG_DEVID_REV_MASK, dev_id),
1836 		    priv->rx_int ? '+' : '-',
1837 		    priv->pll_enable ? '+' : '-',
1838 		    MCP251XFD_QUIRK_ACTIVE(MAB_NO_WARN),
1839 		    MCP251XFD_QUIRK_ACTIVE(CRC_REG),
1840 		    MCP251XFD_QUIRK_ACTIVE(CRC_RX),
1841 		    MCP251XFD_QUIRK_ACTIVE(CRC_TX),
1842 		    MCP251XFD_QUIRK_ACTIVE(ECC),
1843 		    MCP251XFD_QUIRK_ACTIVE(HALF_DUPLEX),
1844 		    clk_rate / 1000000,
1845 		    clk_rate % 1000000 / 1000 / 10,
1846 		    priv->can.clock.freq / 1000000,
1847 		    priv->can.clock.freq % 1000000 / 1000 / 10,
1848 		    priv->spi_max_speed_hz_orig / 1000000,
1849 		    priv->spi_max_speed_hz_orig % 1000000 / 1000 / 10,
1850 		    priv->spi_max_speed_hz_slow / 1000000,
1851 		    priv->spi_max_speed_hz_slow % 1000000 / 1000 / 10,
1852 		    effective_speed_hz_slow / 1000000,
1853 		    effective_speed_hz_slow % 1000000 / 1000 / 10,
1854 		    priv->spi_max_speed_hz_fast / 1000000,
1855 		    priv->spi_max_speed_hz_fast % 1000000 / 1000 / 10,
1856 		    effective_speed_hz_fast / 1000000,
1857 		    effective_speed_hz_fast % 1000000 / 1000 / 10);
1858 
1859 	return 0;
1860 }
1861 
1862 static int mcp251xfd_register(struct mcp251xfd_priv *priv)
1863 {
1864 	struct net_device *ndev = priv->ndev;
1865 	int err;
1866 
1867 	err = mcp251xfd_clks_and_vdd_enable(priv);
1868 	if (err)
1869 		return err;
1870 
1871 	pm_runtime_get_noresume(ndev->dev.parent);
1872 	err = pm_runtime_set_active(ndev->dev.parent);
1873 	if (err)
1874 		goto out_runtime_put_noidle;
1875 	pm_runtime_enable(ndev->dev.parent);
1876 
1877 	mcp251xfd_register_quirks(priv);
1878 
1879 	err = mcp251xfd_chip_softreset(priv);
1880 	if (err == -ENODEV)
1881 		goto out_runtime_disable;
1882 	if (err)
1883 		goto out_chip_sleep;
1884 
1885 	err = mcp251xfd_chip_clock_init(priv);
1886 	if (err == -ENODEV)
1887 		goto out_runtime_disable;
1888 	if (err)
1889 		goto out_chip_sleep;
1890 
1891 	err = mcp251xfd_register_chip_detect(priv);
1892 	if (err)
1893 		goto out_chip_sleep;
1894 
1895 	err = mcp251xfd_register_check_rx_int(priv);
1896 	if (err)
1897 		goto out_chip_sleep;
1898 
1899 	mcp251xfd_ethtool_init(priv);
1900 
1901 	err = register_candev(ndev);
1902 	if (err)
1903 		goto out_chip_sleep;
1904 
1905 	err = mcp251xfd_register_done(priv);
1906 	if (err)
1907 		goto out_unregister_candev;
1908 
1909 	/* Put controller into sleep mode and let pm_runtime_put()
1910 	 * disable the clocks and vdd. If CONFIG_PM is not enabled,
1911 	 * the clocks and vdd will stay powered.
1912 	 */
1913 	err = mcp251xfd_chip_sleep(priv);
1914 	if (err)
1915 		goto out_unregister_candev;
1916 
1917 	pm_runtime_put(ndev->dev.parent);
1918 
1919 	return 0;
1920 
1921  out_unregister_candev:
1922 	unregister_candev(ndev);
1923  out_chip_sleep:
1924 	mcp251xfd_chip_sleep(priv);
1925  out_runtime_disable:
1926 	pm_runtime_disable(ndev->dev.parent);
1927  out_runtime_put_noidle:
1928 	pm_runtime_put_noidle(ndev->dev.parent);
1929 	mcp251xfd_clks_and_vdd_disable(priv);
1930 
1931 	return err;
1932 }
1933 
1934 static inline void mcp251xfd_unregister(struct mcp251xfd_priv *priv)
1935 {
1936 	struct net_device *ndev	= priv->ndev;
1937 
1938 	unregister_candev(ndev);
1939 
1940 	if (pm_runtime_enabled(ndev->dev.parent))
1941 		pm_runtime_disable(ndev->dev.parent);
1942 	else
1943 		mcp251xfd_clks_and_vdd_disable(priv);
1944 }
1945 
1946 static const struct of_device_id mcp251xfd_of_match[] = {
1947 	{
1948 		.compatible = "microchip,mcp2517fd",
1949 		.data = &mcp251xfd_devtype_data_mcp2517fd,
1950 	}, {
1951 		.compatible = "microchip,mcp2518fd",
1952 		.data = &mcp251xfd_devtype_data_mcp2518fd,
1953 	}, {
1954 		.compatible = "microchip,mcp251863",
1955 		.data = &mcp251xfd_devtype_data_mcp251863,
1956 	}, {
1957 		.compatible = "microchip,mcp251xfd",
1958 		.data = &mcp251xfd_devtype_data_mcp251xfd,
1959 	}, {
1960 		/* sentinel */
1961 	},
1962 };
1963 MODULE_DEVICE_TABLE(of, mcp251xfd_of_match);
1964 
1965 static const struct spi_device_id mcp251xfd_id_table[] = {
1966 	{
1967 		.name = "mcp2517fd",
1968 		.driver_data = (kernel_ulong_t)&mcp251xfd_devtype_data_mcp2517fd,
1969 	}, {
1970 		.name = "mcp2518fd",
1971 		.driver_data = (kernel_ulong_t)&mcp251xfd_devtype_data_mcp2518fd,
1972 	}, {
1973 		.name = "mcp251863",
1974 		.driver_data = (kernel_ulong_t)&mcp251xfd_devtype_data_mcp251863,
1975 	}, {
1976 		.name = "mcp251xfd",
1977 		.driver_data = (kernel_ulong_t)&mcp251xfd_devtype_data_mcp251xfd,
1978 	}, {
1979 		/* sentinel */
1980 	},
1981 };
1982 MODULE_DEVICE_TABLE(spi, mcp251xfd_id_table);
1983 
1984 static int mcp251xfd_probe(struct spi_device *spi)
1985 {
1986 	const void *match;
1987 	struct net_device *ndev;
1988 	struct mcp251xfd_priv *priv;
1989 	struct gpio_desc *rx_int;
1990 	struct regulator *reg_vdd, *reg_xceiver;
1991 	struct clk *clk;
1992 	bool pll_enable = false;
1993 	u32 freq = 0;
1994 	int err;
1995 
1996 	if (!spi->irq)
1997 		return dev_err_probe(&spi->dev, -ENXIO,
1998 				     "No IRQ specified (maybe node \"interrupts-extended\" in DT missing)!\n");
1999 
2000 	rx_int = devm_gpiod_get_optional(&spi->dev, "microchip,rx-int",
2001 					 GPIOD_IN);
2002 	if (IS_ERR(rx_int))
2003 		return dev_err_probe(&spi->dev, PTR_ERR(rx_int),
2004 				     "Failed to get RX-INT!\n");
2005 
2006 	reg_vdd = devm_regulator_get_optional(&spi->dev, "vdd");
2007 	if (PTR_ERR(reg_vdd) == -ENODEV)
2008 		reg_vdd = NULL;
2009 	else if (IS_ERR(reg_vdd))
2010 		return dev_err_probe(&spi->dev, PTR_ERR(reg_vdd),
2011 				     "Failed to get VDD regulator!\n");
2012 
2013 	reg_xceiver = devm_regulator_get_optional(&spi->dev, "xceiver");
2014 	if (PTR_ERR(reg_xceiver) == -ENODEV)
2015 		reg_xceiver = NULL;
2016 	else if (IS_ERR(reg_xceiver))
2017 		return dev_err_probe(&spi->dev, PTR_ERR(reg_xceiver),
2018 				     "Failed to get Transceiver regulator!\n");
2019 
2020 	clk = devm_clk_get_optional(&spi->dev, NULL);
2021 	if (IS_ERR(clk))
2022 		return dev_err_probe(&spi->dev, PTR_ERR(clk),
2023 				     "Failed to get Oscillator (clock)!\n");
2024 	if (clk) {
2025 		freq = clk_get_rate(clk);
2026 	} else {
2027 		err = device_property_read_u32(&spi->dev, "clock-frequency",
2028 					       &freq);
2029 		if (err)
2030 			return dev_err_probe(&spi->dev, err,
2031 					     "Failed to get clock-frequency!\n");
2032 	}
2033 
2034 	/* Sanity check */
2035 	if (freq < MCP251XFD_SYSCLOCK_HZ_MIN ||
2036 	    freq > MCP251XFD_SYSCLOCK_HZ_MAX) {
2037 		dev_err(&spi->dev,
2038 			"Oscillator frequency (%u Hz) is too low or high.\n",
2039 			freq);
2040 		return -ERANGE;
2041 	}
2042 
2043 	if (freq <= MCP251XFD_SYSCLOCK_HZ_MAX / MCP251XFD_OSC_PLL_MULTIPLIER)
2044 		pll_enable = true;
2045 
2046 	ndev = alloc_candev(sizeof(struct mcp251xfd_priv),
2047 			    MCP251XFD_TX_OBJ_NUM_MAX);
2048 	if (!ndev)
2049 		return -ENOMEM;
2050 
2051 	SET_NETDEV_DEV(ndev, &spi->dev);
2052 
2053 	ndev->netdev_ops = &mcp251xfd_netdev_ops;
2054 	ndev->irq = spi->irq;
2055 	ndev->flags |= IFF_ECHO;
2056 
2057 	priv = netdev_priv(ndev);
2058 	spi_set_drvdata(spi, priv);
2059 	priv->can.clock.freq = freq;
2060 	if (pll_enable)
2061 		priv->can.clock.freq *= MCP251XFD_OSC_PLL_MULTIPLIER;
2062 	priv->can.do_set_mode = mcp251xfd_set_mode;
2063 	priv->can.do_get_berr_counter = mcp251xfd_get_berr_counter;
2064 	priv->can.bittiming_const = &mcp251xfd_bittiming_const;
2065 	priv->can.data_bittiming_const = &mcp251xfd_data_bittiming_const;
2066 	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
2067 		CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_BERR_REPORTING |
2068 		CAN_CTRLMODE_FD | CAN_CTRLMODE_FD_NON_ISO |
2069 		CAN_CTRLMODE_CC_LEN8_DLC;
2070 	set_bit(MCP251XFD_FLAGS_DOWN, priv->flags);
2071 	priv->ndev = ndev;
2072 	priv->spi = spi;
2073 	priv->rx_int = rx_int;
2074 	priv->clk = clk;
2075 	priv->pll_enable = pll_enable;
2076 	priv->reg_vdd = reg_vdd;
2077 	priv->reg_xceiver = reg_xceiver;
2078 
2079 	match = device_get_match_data(&spi->dev);
2080 	if (match)
2081 		priv->devtype_data = *(struct mcp251xfd_devtype_data *)match;
2082 	else
2083 		priv->devtype_data = *(struct mcp251xfd_devtype_data *)
2084 			spi_get_device_id(spi)->driver_data;
2085 
2086 	/* Errata Reference:
2087 	 * mcp2517fd: DS80000792C 5., mcp2518fd: DS80000789C 4.
2088 	 *
2089 	 * The SPI can write corrupted data to the RAM at fast SPI
2090 	 * speeds:
2091 	 *
2092 	 * Simultaneous activity on the CAN bus while writing data to
2093 	 * RAM via the SPI interface, with high SCK frequency, can
2094 	 * lead to corrupted data being written to RAM.
2095 	 *
2096 	 * Fix/Work Around:
2097 	 * Ensure that FSCK is less than or equal to 0.85 *
2098 	 * (FSYSCLK/2).
2099 	 *
2100 	 * Known good combinations are:
2101 	 *
2102 	 * MCP	ext-clk	SoC			SPI			SPI-clk		max-clk	parent-clk	config
2103 	 *
2104 	 * 2518	20 MHz	allwinner,sun8i-h3	allwinner,sun8i-h3-spi	 8333333 Hz	 83.33%	600000000 Hz	assigned-clocks = <&ccu CLK_SPIx>
2105 	 * 2518	40 MHz	allwinner,sun8i-h3	allwinner,sun8i-h3-spi	16666667 Hz	 83.33%	600000000 Hz	assigned-clocks = <&ccu CLK_SPIx>
2106 	 * 2517	40 MHz	atmel,sama5d27		atmel,at91rm9200-spi	16400000 Hz	 82.00%	 82000000 Hz	default
2107 	 * 2518	40 MHz	atmel,sama5d27		atmel,at91rm9200-spi	16400000 Hz	 82.00%	 82000000 Hz	default
2108 	 * 2518	40 MHz	fsl,imx6dl		fsl,imx51-ecspi		15000000 Hz	 75.00%	 30000000 Hz	default
2109 	 * 2517	20 MHz	fsl,imx8mm		fsl,imx51-ecspi		 8333333 Hz	 83.33%	 16666667 Hz	assigned-clocks = <&clk IMX8MM_CLK_ECSPIx_ROOT>
2110 	 *
2111 	 */
2112 	priv->spi_max_speed_hz_orig = spi->max_speed_hz;
2113 	priv->spi_max_speed_hz_slow = min(spi->max_speed_hz,
2114 					  freq / 2 / 1000 * 850);
2115 	if (priv->pll_enable)
2116 		priv->spi_max_speed_hz_fast = min(spi->max_speed_hz,
2117 						  freq *
2118 						  MCP251XFD_OSC_PLL_MULTIPLIER /
2119 						  2 / 1000 * 850);
2120 	else
2121 		priv->spi_max_speed_hz_fast = priv->spi_max_speed_hz_slow;
2122 	spi->max_speed_hz = priv->spi_max_speed_hz_slow;
2123 	spi->bits_per_word = 8;
2124 	spi->rt = true;
2125 	err = spi_setup(spi);
2126 	if (err)
2127 		goto out_free_candev;
2128 
2129 	err = mcp251xfd_regmap_init(priv);
2130 	if (err)
2131 		goto out_free_candev;
2132 
2133 	err = can_rx_offload_add_manual(ndev, &priv->offload,
2134 					MCP251XFD_NAPI_WEIGHT);
2135 	if (err)
2136 		goto out_free_candev;
2137 
2138 	err = mcp251xfd_register(priv);
2139 	if (err) {
2140 		dev_err_probe(&spi->dev, err, "Failed to detect %s.\n",
2141 			      mcp251xfd_get_model_str(priv));
2142 		goto out_can_rx_offload_del;
2143 	}
2144 
2145 	return 0;
2146 
2147  out_can_rx_offload_del:
2148 	can_rx_offload_del(&priv->offload);
2149  out_free_candev:
2150 	spi->max_speed_hz = priv->spi_max_speed_hz_orig;
2151 
2152 	free_candev(ndev);
2153 
2154 	return err;
2155 }
2156 
2157 static void mcp251xfd_remove(struct spi_device *spi)
2158 {
2159 	struct mcp251xfd_priv *priv = spi_get_drvdata(spi);
2160 	struct net_device *ndev = priv->ndev;
2161 
2162 	can_rx_offload_del(&priv->offload);
2163 	mcp251xfd_unregister(priv);
2164 	spi->max_speed_hz = priv->spi_max_speed_hz_orig;
2165 	free_candev(ndev);
2166 }
2167 
2168 static int __maybe_unused mcp251xfd_runtime_suspend(struct device *device)
2169 {
2170 	const struct mcp251xfd_priv *priv = dev_get_drvdata(device);
2171 
2172 	return mcp251xfd_clks_and_vdd_disable(priv);
2173 }
2174 
2175 static int __maybe_unused mcp251xfd_runtime_resume(struct device *device)
2176 {
2177 	const struct mcp251xfd_priv *priv = dev_get_drvdata(device);
2178 
2179 	return mcp251xfd_clks_and_vdd_enable(priv);
2180 }
2181 
2182 static const struct dev_pm_ops mcp251xfd_pm_ops = {
2183 	SET_RUNTIME_PM_OPS(mcp251xfd_runtime_suspend,
2184 			   mcp251xfd_runtime_resume, NULL)
2185 };
2186 
2187 static struct spi_driver mcp251xfd_driver = {
2188 	.driver = {
2189 		.name = DEVICE_NAME,
2190 		.pm = &mcp251xfd_pm_ops,
2191 		.of_match_table = mcp251xfd_of_match,
2192 	},
2193 	.probe = mcp251xfd_probe,
2194 	.remove = mcp251xfd_remove,
2195 	.id_table = mcp251xfd_id_table,
2196 };
2197 module_spi_driver(mcp251xfd_driver);
2198 
2199 MODULE_AUTHOR("Marc Kleine-Budde <mkl@pengutronix.de>");
2200 MODULE_DESCRIPTION("Microchip MCP251xFD Family CAN controller driver");
2201 MODULE_LICENSE("GPL v2");
2202