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 
__mcp251xfd_get_model_str(enum mcp251xfd_model model)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 *
mcp251xfd_get_model_str(const struct mcp251xfd_priv * priv)95 mcp251xfd_get_model_str(const struct mcp251xfd_priv *priv)
96 {
97 	return __mcp251xfd_get_model_str(priv->devtype_data.model);
98 }
99 
mcp251xfd_get_mode_str(const u8 mode)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 *
mcp251xfd_get_osc_str(const u32 osc,const u32 osc_reference)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 
mcp251xfd_vdd_enable(const struct mcp251xfd_priv * priv)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 
mcp251xfd_vdd_disable(const struct mcp251xfd_priv * priv)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
mcp251xfd_transceiver_enable(const struct mcp251xfd_priv * priv)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
mcp251xfd_transceiver_disable(const struct mcp251xfd_priv * priv)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 
mcp251xfd_clks_and_vdd_enable(const struct mcp251xfd_priv * priv)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 
mcp251xfd_clks_and_vdd_disable(const struct mcp251xfd_priv * priv)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 
mcp251xfd_reg_invalid(u32 reg)206 static inline bool mcp251xfd_reg_invalid(u32 reg)
207 {
208 	return reg == 0x0 || reg == 0xffffffff;
209 }
210 
211 static inline int
mcp251xfd_chip_get_mode(const struct mcp251xfd_priv * priv,u8 * mode)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
__mcp251xfd_chip_set_mode(const struct mcp251xfd_priv * priv,const u8 mode_req,bool nowait)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
mcp251xfd_chip_set_mode(const struct mcp251xfd_priv * priv,const u8 mode_req)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
mcp251xfd_chip_set_mode_nowait(const struct mcp251xfd_priv * priv,const u8 mode_req)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
mcp251xfd_chip_wait_for_osc_ready(const struct mcp251xfd_priv * priv,u32 osc_reference,u32 osc_mask)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 
mcp251xfd_chip_wake(const struct mcp251xfd_priv * priv)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 
mcp251xfd_chip_sleep(const struct mcp251xfd_priv * priv)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 
mcp251xfd_chip_softreset_do(const struct mcp251xfd_priv * priv)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 
mcp251xfd_chip_softreset_check(const struct mcp251xfd_priv * priv)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 
mcp251xfd_chip_softreset(const struct mcp251xfd_priv * priv)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 
mcp251xfd_chip_clock_init(const struct mcp251xfd_priv * priv)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 
mcp251xfd_chip_timestamp_init(const struct mcp251xfd_priv * priv)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 
mcp251xfd_set_bittiming(const struct mcp251xfd_priv * priv)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 
mcp251xfd_chip_rx_int_enable(const struct mcp251xfd_priv * priv)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 
mcp251xfd_chip_rx_int_disable(const struct mcp251xfd_priv * priv)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 
mcp251xfd_chip_ecc_init(struct mcp251xfd_priv * priv)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 
mcp251xfd_get_normal_mode(const struct mcp251xfd_priv * priv)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
__mcp251xfd_chip_set_normal_mode(const struct mcp251xfd_priv * priv,bool nowait)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
mcp251xfd_chip_set_normal_mode(const struct mcp251xfd_priv * priv)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
mcp251xfd_chip_set_normal_mode_nowait(const struct mcp251xfd_priv * priv)686 mcp251xfd_chip_set_normal_mode_nowait(const struct mcp251xfd_priv *priv)
687 {
688 	return __mcp251xfd_chip_set_normal_mode(priv, true);
689 }
690 
mcp251xfd_chip_interrupts_enable(const struct mcp251xfd_priv * priv)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 
mcp251xfd_chip_interrupts_disable(const struct mcp251xfd_priv * priv)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 
mcp251xfd_chip_stop(struct mcp251xfd_priv * priv,const enum can_state state)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_chip_sleep(priv);
748 }
749 
mcp251xfd_chip_start(struct mcp251xfd_priv * priv)750 static int mcp251xfd_chip_start(struct mcp251xfd_priv *priv)
751 {
752 	int err;
753 
754 	err = mcp251xfd_chip_softreset(priv);
755 	if (err)
756 		goto out_chip_stop;
757 
758 	err = mcp251xfd_chip_clock_init(priv);
759 	if (err)
760 		goto out_chip_stop;
761 
762 	err = mcp251xfd_chip_timestamp_init(priv);
763 	if (err)
764 		goto out_chip_stop;
765 
766 	err = mcp251xfd_set_bittiming(priv);
767 	if (err)
768 		goto out_chip_stop;
769 
770 	err = mcp251xfd_chip_rx_int_enable(priv);
771 	if (err)
772 		goto out_chip_stop;
773 
774 	err = mcp251xfd_chip_ecc_init(priv);
775 	if (err)
776 		goto out_chip_stop;
777 
778 	err = mcp251xfd_ring_init(priv);
779 	if (err)
780 		goto out_chip_stop;
781 
782 	err = mcp251xfd_chip_fifo_init(priv);
783 	if (err)
784 		goto out_chip_stop;
785 
786 	priv->can.state = CAN_STATE_ERROR_ACTIVE;
787 
788 	err = mcp251xfd_chip_set_normal_mode(priv);
789 	if (err)
790 		goto out_chip_stop;
791 
792 	return 0;
793 
794  out_chip_stop:
795 	mcp251xfd_dump(priv);
796 	mcp251xfd_chip_stop(priv, CAN_STATE_STOPPED);
797 
798 	return err;
799 }
800 
mcp251xfd_set_mode(struct net_device * ndev,enum can_mode mode)801 static int mcp251xfd_set_mode(struct net_device *ndev, enum can_mode mode)
802 {
803 	struct mcp251xfd_priv *priv = netdev_priv(ndev);
804 	int err;
805 
806 	switch (mode) {
807 	case CAN_MODE_START:
808 		err = mcp251xfd_chip_start(priv);
809 		if (err)
810 			return err;
811 
812 		err = mcp251xfd_chip_interrupts_enable(priv);
813 		if (err) {
814 			mcp251xfd_chip_stop(priv, CAN_STATE_STOPPED);
815 			return err;
816 		}
817 
818 		netif_wake_queue(ndev);
819 		break;
820 
821 	default:
822 		return -EOPNOTSUPP;
823 	}
824 
825 	return 0;
826 }
827 
__mcp251xfd_get_berr_counter(const struct net_device * ndev,struct can_berr_counter * bec)828 static int __mcp251xfd_get_berr_counter(const struct net_device *ndev,
829 					struct can_berr_counter *bec)
830 {
831 	const struct mcp251xfd_priv *priv = netdev_priv(ndev);
832 	u32 trec;
833 	int err;
834 
835 	err = regmap_read(priv->map_reg, MCP251XFD_REG_TREC, &trec);
836 	if (err)
837 		return err;
838 
839 	if (trec & MCP251XFD_REG_TREC_TXBO)
840 		bec->txerr = 256;
841 	else
842 		bec->txerr = FIELD_GET(MCP251XFD_REG_TREC_TEC_MASK, trec);
843 	bec->rxerr = FIELD_GET(MCP251XFD_REG_TREC_REC_MASK, trec);
844 
845 	return 0;
846 }
847 
mcp251xfd_get_berr_counter(const struct net_device * ndev,struct can_berr_counter * bec)848 static int mcp251xfd_get_berr_counter(const struct net_device *ndev,
849 				      struct can_berr_counter *bec)
850 {
851 	const struct mcp251xfd_priv *priv = netdev_priv(ndev);
852 
853 	/* Avoid waking up the controller if the interface is down */
854 	if (!(ndev->flags & IFF_UP))
855 		return 0;
856 
857 	/* The controller is powered down during Bus Off, use saved
858 	 * bec values.
859 	 */
860 	if (priv->can.state == CAN_STATE_BUS_OFF) {
861 		*bec = priv->bec;
862 		return 0;
863 	}
864 
865 	return __mcp251xfd_get_berr_counter(ndev, bec);
866 }
867 
868 static struct sk_buff *
mcp251xfd_alloc_can_err_skb(struct mcp251xfd_priv * priv,struct can_frame ** cf,u32 * timestamp)869 mcp251xfd_alloc_can_err_skb(struct mcp251xfd_priv *priv,
870 			    struct can_frame **cf, u32 *timestamp)
871 {
872 	struct sk_buff *skb;
873 	int err;
874 
875 	err = mcp251xfd_get_timestamp(priv, timestamp);
876 	if (err)
877 		return NULL;
878 
879 	skb = alloc_can_err_skb(priv->ndev, cf);
880 	if (skb)
881 		mcp251xfd_skb_set_timestamp(priv, skb, *timestamp);
882 
883 	return skb;
884 }
885 
mcp251xfd_handle_rxovif(struct mcp251xfd_priv * priv)886 static int mcp251xfd_handle_rxovif(struct mcp251xfd_priv *priv)
887 {
888 	struct net_device_stats *stats = &priv->ndev->stats;
889 	struct mcp251xfd_rx_ring *ring;
890 	struct sk_buff *skb;
891 	struct can_frame *cf;
892 	u32 timestamp, rxovif;
893 	int err, i;
894 
895 	stats->rx_over_errors++;
896 	stats->rx_errors++;
897 
898 	err = regmap_read(priv->map_reg, MCP251XFD_REG_RXOVIF, &rxovif);
899 	if (err)
900 		return err;
901 
902 	mcp251xfd_for_each_rx_ring(priv, ring, i) {
903 		if (!(rxovif & BIT(ring->fifo_nr)))
904 			continue;
905 
906 		/* If SERRIF is active, there was a RX MAB overflow. */
907 		if (priv->regs_status.intf & MCP251XFD_REG_INT_SERRIF) {
908 			if (net_ratelimit())
909 				netdev_dbg(priv->ndev,
910 					   "RX-%d: MAB overflow detected.\n",
911 					   ring->nr);
912 		} else {
913 			if (net_ratelimit())
914 				netdev_dbg(priv->ndev,
915 					   "RX-%d: FIFO overflow.\n",
916 					   ring->nr);
917 		}
918 
919 		err = regmap_update_bits(priv->map_reg,
920 					 MCP251XFD_REG_FIFOSTA(ring->fifo_nr),
921 					 MCP251XFD_REG_FIFOSTA_RXOVIF,
922 					 0x0);
923 		if (err)
924 			return err;
925 	}
926 
927 	skb = mcp251xfd_alloc_can_err_skb(priv, &cf, &timestamp);
928 	if (!skb)
929 		return 0;
930 
931 	cf->can_id |= CAN_ERR_CRTL;
932 	cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
933 
934 	err = can_rx_offload_queue_timestamp(&priv->offload, skb, timestamp);
935 	if (err)
936 		stats->rx_fifo_errors++;
937 
938 	return 0;
939 }
940 
mcp251xfd_handle_txatif(struct mcp251xfd_priv * priv)941 static int mcp251xfd_handle_txatif(struct mcp251xfd_priv *priv)
942 {
943 	netdev_info(priv->ndev, "%s\n", __func__);
944 
945 	return 0;
946 }
947 
mcp251xfd_handle_ivmif(struct mcp251xfd_priv * priv)948 static int mcp251xfd_handle_ivmif(struct mcp251xfd_priv *priv)
949 {
950 	struct net_device_stats *stats = &priv->ndev->stats;
951 	u32 bdiag1, timestamp;
952 	struct sk_buff *skb;
953 	struct can_frame *cf = NULL;
954 	int err;
955 
956 	err = mcp251xfd_get_timestamp(priv, &timestamp);
957 	if (err)
958 		return err;
959 
960 	err = regmap_read(priv->map_reg, MCP251XFD_REG_BDIAG1, &bdiag1);
961 	if (err)
962 		return err;
963 
964 	/* Write 0s to clear error bits, don't write 1s to non active
965 	 * bits, as they will be set.
966 	 */
967 	err = regmap_write(priv->map_reg, MCP251XFD_REG_BDIAG1, 0x0);
968 	if (err)
969 		return err;
970 
971 	priv->can.can_stats.bus_error++;
972 
973 	skb = alloc_can_err_skb(priv->ndev, &cf);
974 	if (cf)
975 		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
976 
977 	/* Controller misconfiguration */
978 	if (WARN_ON(bdiag1 & MCP251XFD_REG_BDIAG1_DLCMM))
979 		netdev_err(priv->ndev,
980 			   "recv'd DLC is larger than PLSIZE of FIFO element.");
981 
982 	/* RX errors */
983 	if (bdiag1 & (MCP251XFD_REG_BDIAG1_DCRCERR |
984 		      MCP251XFD_REG_BDIAG1_NCRCERR)) {
985 		netdev_dbg(priv->ndev, "CRC error\n");
986 
987 		stats->rx_errors++;
988 		if (cf)
989 			cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
990 	}
991 	if (bdiag1 & (MCP251XFD_REG_BDIAG1_DSTUFERR |
992 		      MCP251XFD_REG_BDIAG1_NSTUFERR)) {
993 		netdev_dbg(priv->ndev, "Stuff error\n");
994 
995 		stats->rx_errors++;
996 		if (cf)
997 			cf->data[2] |= CAN_ERR_PROT_STUFF;
998 	}
999 	if (bdiag1 & (MCP251XFD_REG_BDIAG1_DFORMERR |
1000 		      MCP251XFD_REG_BDIAG1_NFORMERR)) {
1001 		netdev_dbg(priv->ndev, "Format error\n");
1002 
1003 		stats->rx_errors++;
1004 		if (cf)
1005 			cf->data[2] |= CAN_ERR_PROT_FORM;
1006 	}
1007 
1008 	/* TX errors */
1009 	if (bdiag1 & MCP251XFD_REG_BDIAG1_NACKERR) {
1010 		netdev_dbg(priv->ndev, "NACK error\n");
1011 
1012 		stats->tx_errors++;
1013 		if (cf) {
1014 			cf->can_id |= CAN_ERR_ACK;
1015 			cf->data[2] |= CAN_ERR_PROT_TX;
1016 		}
1017 	}
1018 	if (bdiag1 & (MCP251XFD_REG_BDIAG1_DBIT1ERR |
1019 		      MCP251XFD_REG_BDIAG1_NBIT1ERR)) {
1020 		netdev_dbg(priv->ndev, "Bit1 error\n");
1021 
1022 		stats->tx_errors++;
1023 		if (cf)
1024 			cf->data[2] |= CAN_ERR_PROT_TX | CAN_ERR_PROT_BIT1;
1025 	}
1026 	if (bdiag1 & (MCP251XFD_REG_BDIAG1_DBIT0ERR |
1027 		      MCP251XFD_REG_BDIAG1_NBIT0ERR)) {
1028 		netdev_dbg(priv->ndev, "Bit0 error\n");
1029 
1030 		stats->tx_errors++;
1031 		if (cf)
1032 			cf->data[2] |= CAN_ERR_PROT_TX | CAN_ERR_PROT_BIT0;
1033 	}
1034 
1035 	if (!cf)
1036 		return 0;
1037 
1038 	mcp251xfd_skb_set_timestamp(priv, skb, timestamp);
1039 	err = can_rx_offload_queue_timestamp(&priv->offload, skb, timestamp);
1040 	if (err)
1041 		stats->rx_fifo_errors++;
1042 
1043 	return 0;
1044 }
1045 
mcp251xfd_handle_cerrif(struct mcp251xfd_priv * priv)1046 static int mcp251xfd_handle_cerrif(struct mcp251xfd_priv *priv)
1047 {
1048 	struct net_device_stats *stats = &priv->ndev->stats;
1049 	struct sk_buff *skb;
1050 	struct can_frame *cf = NULL;
1051 	enum can_state new_state, rx_state, tx_state;
1052 	u32 trec, timestamp;
1053 	int err;
1054 
1055 	err = regmap_read(priv->map_reg, MCP251XFD_REG_TREC, &trec);
1056 	if (err)
1057 		return err;
1058 
1059 	if (trec & MCP251XFD_REG_TREC_TXBO)
1060 		tx_state = CAN_STATE_BUS_OFF;
1061 	else if (trec & MCP251XFD_REG_TREC_TXBP)
1062 		tx_state = CAN_STATE_ERROR_PASSIVE;
1063 	else if (trec & MCP251XFD_REG_TREC_TXWARN)
1064 		tx_state = CAN_STATE_ERROR_WARNING;
1065 	else
1066 		tx_state = CAN_STATE_ERROR_ACTIVE;
1067 
1068 	if (trec & MCP251XFD_REG_TREC_RXBP)
1069 		rx_state = CAN_STATE_ERROR_PASSIVE;
1070 	else if (trec & MCP251XFD_REG_TREC_RXWARN)
1071 		rx_state = CAN_STATE_ERROR_WARNING;
1072 	else
1073 		rx_state = CAN_STATE_ERROR_ACTIVE;
1074 
1075 	new_state = max(tx_state, rx_state);
1076 	if (new_state == priv->can.state)
1077 		return 0;
1078 
1079 	/* The skb allocation might fail, but can_change_state()
1080 	 * handles cf == NULL.
1081 	 */
1082 	skb = mcp251xfd_alloc_can_err_skb(priv, &cf, &timestamp);
1083 	can_change_state(priv->ndev, cf, tx_state, rx_state);
1084 
1085 	if (new_state == CAN_STATE_BUS_OFF) {
1086 		/* As we're going to switch off the chip now, let's
1087 		 * save the error counters and return them to
1088 		 * userspace, if do_get_berr_counter() is called while
1089 		 * the chip is in Bus Off.
1090 		 */
1091 		err = __mcp251xfd_get_berr_counter(priv->ndev, &priv->bec);
1092 		if (err)
1093 			return err;
1094 
1095 		mcp251xfd_chip_stop(priv, CAN_STATE_BUS_OFF);
1096 		can_bus_off(priv->ndev);
1097 	}
1098 
1099 	if (!skb)
1100 		return 0;
1101 
1102 	if (new_state != CAN_STATE_BUS_OFF) {
1103 		struct can_berr_counter bec;
1104 
1105 		err = mcp251xfd_get_berr_counter(priv->ndev, &bec);
1106 		if (err)
1107 			return err;
1108 		cf->can_id |= CAN_ERR_CNT;
1109 		cf->data[6] = bec.txerr;
1110 		cf->data[7] = bec.rxerr;
1111 	}
1112 
1113 	err = can_rx_offload_queue_timestamp(&priv->offload, skb, timestamp);
1114 	if (err)
1115 		stats->rx_fifo_errors++;
1116 
1117 	return 0;
1118 }
1119 
1120 static int
mcp251xfd_handle_modif(const struct mcp251xfd_priv * priv,bool * set_normal_mode)1121 mcp251xfd_handle_modif(const struct mcp251xfd_priv *priv, bool *set_normal_mode)
1122 {
1123 	const u8 mode_reference = mcp251xfd_get_normal_mode(priv);
1124 	u8 mode;
1125 	int err;
1126 
1127 	err = mcp251xfd_chip_get_mode(priv, &mode);
1128 	if (err)
1129 		return err;
1130 
1131 	if (mode == mode_reference) {
1132 		netdev_dbg(priv->ndev,
1133 			   "Controller changed into %s Mode (%u).\n",
1134 			   mcp251xfd_get_mode_str(mode), mode);
1135 		return 0;
1136 	}
1137 
1138 	/* According to MCP2517FD errata DS80000792B 1., during a TX
1139 	 * MAB underflow, the controller will transition to Restricted
1140 	 * Operation Mode or Listen Only Mode (depending on SERR2LOM).
1141 	 *
1142 	 * However this is not always the case. If SERR2LOM is
1143 	 * configured for Restricted Operation Mode (SERR2LOM not set)
1144 	 * the MCP2517FD will sometimes transition to Listen Only Mode
1145 	 * first. When polling this bit we see that it will transition
1146 	 * to Restricted Operation Mode shortly after.
1147 	 */
1148 	if ((priv->devtype_data.quirks & MCP251XFD_QUIRK_MAB_NO_WARN) &&
1149 	    (mode == MCP251XFD_REG_CON_MODE_RESTRICTED ||
1150 	     mode == MCP251XFD_REG_CON_MODE_LISTENONLY))
1151 		netdev_dbg(priv->ndev,
1152 			   "Controller changed into %s Mode (%u).\n",
1153 			   mcp251xfd_get_mode_str(mode), mode);
1154 	else
1155 		netdev_err(priv->ndev,
1156 			   "Controller changed into %s Mode (%u).\n",
1157 			   mcp251xfd_get_mode_str(mode), mode);
1158 
1159 	/* After the application requests Normal mode, the controller
1160 	 * will automatically attempt to retransmit the message that
1161 	 * caused the TX MAB underflow.
1162 	 *
1163 	 * However, if there is an ECC error in the TX-RAM, we first
1164 	 * have to reload the tx-object before requesting Normal
1165 	 * mode. This is done later in mcp251xfd_handle_eccif().
1166 	 */
1167 	if (priv->regs_status.intf & MCP251XFD_REG_INT_ECCIF) {
1168 		*set_normal_mode = true;
1169 		return 0;
1170 	}
1171 
1172 	return mcp251xfd_chip_set_normal_mode_nowait(priv);
1173 }
1174 
mcp251xfd_handle_serrif(struct mcp251xfd_priv * priv)1175 static int mcp251xfd_handle_serrif(struct mcp251xfd_priv *priv)
1176 {
1177 	struct mcp251xfd_ecc *ecc = &priv->ecc;
1178 	struct net_device_stats *stats = &priv->ndev->stats;
1179 	bool handled = false;
1180 
1181 	/* TX MAB underflow
1182 	 *
1183 	 * According to MCP2517FD Errata DS80000792B 1. a TX MAB
1184 	 * underflow is indicated by SERRIF and MODIF.
1185 	 *
1186 	 * In addition to the effects mentioned in the Errata, there
1187 	 * are Bus Errors due to the aborted CAN frame, so a IVMIF
1188 	 * will be seen as well.
1189 	 *
1190 	 * Sometimes there is an ECC error in the TX-RAM, which leads
1191 	 * to a TX MAB underflow.
1192 	 *
1193 	 * However, probably due to a race condition, there is no
1194 	 * associated MODIF pending.
1195 	 *
1196 	 * Further, there are situations, where the SERRIF is caused
1197 	 * by an ECC error in the TX-RAM, but not even the ECCIF is
1198 	 * set. This only seems to happen _after_ the first occurrence
1199 	 * of a ECCIF (which is tracked in ecc->cnt).
1200 	 *
1201 	 * Treat all as a known system errors..
1202 	 */
1203 	if ((priv->regs_status.intf & MCP251XFD_REG_INT_MODIF &&
1204 	     priv->regs_status.intf & MCP251XFD_REG_INT_IVMIF) ||
1205 	    priv->regs_status.intf & MCP251XFD_REG_INT_ECCIF ||
1206 	    ecc->cnt) {
1207 		const char *msg;
1208 
1209 		if (priv->regs_status.intf & MCP251XFD_REG_INT_ECCIF ||
1210 		    ecc->cnt)
1211 			msg = "TX MAB underflow due to ECC error detected.";
1212 		else
1213 			msg = "TX MAB underflow detected.";
1214 
1215 		if (priv->devtype_data.quirks & MCP251XFD_QUIRK_MAB_NO_WARN)
1216 			netdev_dbg(priv->ndev, "%s\n", msg);
1217 		else
1218 			netdev_info(priv->ndev, "%s\n", msg);
1219 
1220 		stats->tx_aborted_errors++;
1221 		stats->tx_errors++;
1222 		handled = true;
1223 	}
1224 
1225 	/* RX MAB overflow
1226 	 *
1227 	 * According to MCP2517FD Errata DS80000792B 1. a RX MAB
1228 	 * overflow is indicated by SERRIF.
1229 	 *
1230 	 * In addition to the effects mentioned in the Errata, (most
1231 	 * of the times) a RXOVIF is raised, if the FIFO that is being
1232 	 * received into has the RXOVIE activated (and we have enabled
1233 	 * RXOVIE on all FIFOs).
1234 	 *
1235 	 * Sometimes there is no RXOVIF just a RXIF is pending.
1236 	 *
1237 	 * Treat all as a known system errors..
1238 	 */
1239 	if (priv->regs_status.intf & MCP251XFD_REG_INT_RXOVIF ||
1240 	    priv->regs_status.intf & MCP251XFD_REG_INT_RXIF) {
1241 		stats->rx_dropped++;
1242 		handled = true;
1243 	}
1244 
1245 	if (!handled)
1246 		netdev_err(priv->ndev,
1247 			   "Unhandled System Error Interrupt (intf=0x%08x)!\n",
1248 			   priv->regs_status.intf);
1249 
1250 	return 0;
1251 }
1252 
1253 static int
mcp251xfd_handle_eccif_recover(struct mcp251xfd_priv * priv,u8 nr)1254 mcp251xfd_handle_eccif_recover(struct mcp251xfd_priv *priv, u8 nr)
1255 {
1256 	struct mcp251xfd_tx_ring *tx_ring = priv->tx;
1257 	struct mcp251xfd_ecc *ecc = &priv->ecc;
1258 	struct mcp251xfd_tx_obj *tx_obj;
1259 	u8 chip_tx_tail, tx_tail, offset;
1260 	u16 addr;
1261 	int err;
1262 
1263 	addr = FIELD_GET(MCP251XFD_REG_ECCSTAT_ERRADDR_MASK, ecc->ecc_stat);
1264 
1265 	err = mcp251xfd_tx_tail_get_from_chip(priv, &chip_tx_tail);
1266 	if (err)
1267 		return err;
1268 
1269 	tx_tail = mcp251xfd_get_tx_tail(tx_ring);
1270 	offset = (nr - chip_tx_tail) & (tx_ring->obj_num - 1);
1271 
1272 	/* Bail out if one of the following is met:
1273 	 * - tx_tail information is inconsistent
1274 	 * - for mcp2517fd: offset not 0
1275 	 * - for mcp2518fd: offset not 0 or 1
1276 	 */
1277 	if (chip_tx_tail != tx_tail ||
1278 	    !(offset == 0 || (offset == 1 && (mcp251xfd_is_2518FD(priv) ||
1279 					      mcp251xfd_is_251863(priv))))) {
1280 		netdev_err(priv->ndev,
1281 			   "ECC Error information inconsistent (addr=0x%04x, nr=%d, tx_tail=0x%08x(%d), chip_tx_tail=%d, offset=%d).\n",
1282 			   addr, nr, tx_ring->tail, tx_tail, chip_tx_tail,
1283 			   offset);
1284 		return -EINVAL;
1285 	}
1286 
1287 	netdev_info(priv->ndev,
1288 		    "Recovering %s ECC Error at address 0x%04x (in TX-RAM, tx_obj=%d, tx_tail=0x%08x(%d), offset=%d).\n",
1289 		    ecc->ecc_stat & MCP251XFD_REG_ECCSTAT_SECIF ?
1290 		    "Single" : "Double",
1291 		    addr, nr, tx_ring->tail, tx_tail, offset);
1292 
1293 	/* reload tx_obj into controller RAM ... */
1294 	tx_obj = &tx_ring->obj[nr];
1295 	err = spi_sync_transfer(priv->spi, tx_obj->xfer, 1);
1296 	if (err)
1297 		return err;
1298 
1299 	/* ... and trigger retransmit */
1300 	return mcp251xfd_chip_set_normal_mode(priv);
1301 }
1302 
1303 static int
mcp251xfd_handle_eccif(struct mcp251xfd_priv * priv,bool set_normal_mode)1304 mcp251xfd_handle_eccif(struct mcp251xfd_priv *priv, bool set_normal_mode)
1305 {
1306 	struct mcp251xfd_ecc *ecc = &priv->ecc;
1307 	const char *msg;
1308 	bool in_tx_ram;
1309 	u32 ecc_stat;
1310 	u16 addr;
1311 	u8 nr;
1312 	int err;
1313 
1314 	err = regmap_read(priv->map_reg, MCP251XFD_REG_ECCSTAT, &ecc_stat);
1315 	if (err)
1316 		return err;
1317 
1318 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_ECCSTAT,
1319 				 MCP251XFD_REG_ECCSTAT_IF_MASK, ~ecc_stat);
1320 	if (err)
1321 		return err;
1322 
1323 	/* Check if ECC error occurred in TX-RAM */
1324 	addr = FIELD_GET(MCP251XFD_REG_ECCSTAT_ERRADDR_MASK, ecc_stat);
1325 	err = mcp251xfd_get_tx_nr_by_addr(priv->tx, &nr, addr);
1326 	if (!err)
1327 		in_tx_ram = true;
1328 	else if (err == -ENOENT)
1329 		in_tx_ram = false;
1330 	else
1331 		return err;
1332 
1333 	/* Errata Reference:
1334 	 * mcp2517fd: DS80000789B, mcp2518fd: DS80000792C 2.
1335 	 *
1336 	 * ECC single error correction does not work in all cases:
1337 	 *
1338 	 * Fix/Work Around:
1339 	 * Enable single error correction and double error detection
1340 	 * interrupts by setting SECIE and DEDIE. Handle SECIF as a
1341 	 * detection interrupt and do not rely on the error
1342 	 * correction. Instead, handle both interrupts as a
1343 	 * notification that the RAM word at ERRADDR was corrupted.
1344 	 */
1345 	if (ecc_stat & MCP251XFD_REG_ECCSTAT_SECIF)
1346 		msg = "Single ECC Error detected at address";
1347 	else if (ecc_stat & MCP251XFD_REG_ECCSTAT_DEDIF)
1348 		msg = "Double ECC Error detected at address";
1349 	else
1350 		return -EINVAL;
1351 
1352 	if (!in_tx_ram) {
1353 		ecc->ecc_stat = 0;
1354 
1355 		netdev_notice(priv->ndev, "%s 0x%04x.\n", msg, addr);
1356 	} else {
1357 		/* Re-occurring error? */
1358 		if (ecc->ecc_stat == ecc_stat) {
1359 			ecc->cnt++;
1360 		} else {
1361 			ecc->ecc_stat = ecc_stat;
1362 			ecc->cnt = 1;
1363 		}
1364 
1365 		netdev_info(priv->ndev,
1366 			    "%s 0x%04x (in TX-RAM, tx_obj=%d), occurred %d time%s.\n",
1367 			    msg, addr, nr, ecc->cnt, ecc->cnt > 1 ? "s" : "");
1368 
1369 		if (ecc->cnt >= MCP251XFD_ECC_CNT_MAX)
1370 			return mcp251xfd_handle_eccif_recover(priv, nr);
1371 	}
1372 
1373 	if (set_normal_mode)
1374 		return mcp251xfd_chip_set_normal_mode_nowait(priv);
1375 
1376 	return 0;
1377 }
1378 
mcp251xfd_handle_spicrcif(struct mcp251xfd_priv * priv)1379 static int mcp251xfd_handle_spicrcif(struct mcp251xfd_priv *priv)
1380 {
1381 	int err;
1382 	u32 crc;
1383 
1384 	err = regmap_read(priv->map_reg, MCP251XFD_REG_CRC, &crc);
1385 	if (err)
1386 		return err;
1387 
1388 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_CRC,
1389 				 MCP251XFD_REG_CRC_IF_MASK,
1390 				 ~crc);
1391 	if (err)
1392 		return err;
1393 
1394 	if (crc & MCP251XFD_REG_CRC_FERRIF)
1395 		netdev_notice(priv->ndev, "CRC write command format error.\n");
1396 	else if (crc & MCP251XFD_REG_CRC_CRCERRIF)
1397 		netdev_notice(priv->ndev,
1398 			      "CRC write error detected. CRC=0x%04lx.\n",
1399 			      FIELD_GET(MCP251XFD_REG_CRC_MASK, crc));
1400 
1401 	return 0;
1402 }
1403 
mcp251xfd_read_regs_status(struct mcp251xfd_priv * priv)1404 static int mcp251xfd_read_regs_status(struct mcp251xfd_priv *priv)
1405 {
1406 	const int val_bytes = regmap_get_val_bytes(priv->map_reg);
1407 	size_t len;
1408 
1409 	if (priv->rx_ring_num == 1)
1410 		len = sizeof(priv->regs_status.intf);
1411 	else
1412 		len = sizeof(priv->regs_status);
1413 
1414 	return regmap_bulk_read(priv->map_reg, MCP251XFD_REG_INT,
1415 				&priv->regs_status, len / val_bytes);
1416 }
1417 
1418 #define mcp251xfd_handle(priv, irq, ...) \
1419 ({ \
1420 	struct mcp251xfd_priv *_priv = (priv); \
1421 	int err; \
1422 \
1423 	err = mcp251xfd_handle_##irq(_priv, ## __VA_ARGS__); \
1424 	if (err) \
1425 		netdev_err(_priv->ndev, \
1426 			"IRQ handler mcp251xfd_handle_%s() returned %d.\n", \
1427 			__stringify(irq), err); \
1428 	err; \
1429 })
1430 
mcp251xfd_irq(int irq,void * dev_id)1431 static irqreturn_t mcp251xfd_irq(int irq, void *dev_id)
1432 {
1433 	struct mcp251xfd_priv *priv = dev_id;
1434 	irqreturn_t handled = IRQ_NONE;
1435 	int err;
1436 
1437 	if (priv->rx_int)
1438 		do {
1439 			int rx_pending;
1440 
1441 			rx_pending = gpiod_get_value_cansleep(priv->rx_int);
1442 			if (!rx_pending)
1443 				break;
1444 
1445 			/* Assume 1st RX-FIFO pending, if other FIFOs
1446 			 * are pending the main IRQ handler will take
1447 			 * care.
1448 			 */
1449 			priv->regs_status.rxif = BIT(priv->rx[0]->fifo_nr);
1450 			err = mcp251xfd_handle(priv, rxif);
1451 			if (err)
1452 				goto out_fail;
1453 
1454 			handled = IRQ_HANDLED;
1455 
1456 			/* We don't know which RX-FIFO is pending, but only
1457 			 * handle the 1st RX-FIFO. Leave loop here if we have
1458 			 * more than 1 RX-FIFO to avoid starvation.
1459 			 */
1460 		} while (priv->rx_ring_num == 1);
1461 
1462 	do {
1463 		u32 intf_pending, intf_pending_clearable;
1464 		bool set_normal_mode = false;
1465 
1466 		err = mcp251xfd_read_regs_status(priv);
1467 		if (err)
1468 			goto out_fail;
1469 
1470 		intf_pending = FIELD_GET(MCP251XFD_REG_INT_IF_MASK,
1471 					 priv->regs_status.intf) &
1472 			FIELD_GET(MCP251XFD_REG_INT_IE_MASK,
1473 				  priv->regs_status.intf);
1474 
1475 		if (!(intf_pending)) {
1476 			can_rx_offload_threaded_irq_finish(&priv->offload);
1477 			return handled;
1478 		}
1479 
1480 		/* Some interrupts must be ACKed in the
1481 		 * MCP251XFD_REG_INT register.
1482 		 * - First ACK then handle, to avoid lost-IRQ race
1483 		 *   condition on fast re-occurring interrupts.
1484 		 * - Write "0" to clear active IRQs, "1" to all other,
1485 		 *   to avoid r/m/w race condition on the
1486 		 *   MCP251XFD_REG_INT register.
1487 		 */
1488 		intf_pending_clearable = intf_pending &
1489 			MCP251XFD_REG_INT_IF_CLEARABLE_MASK;
1490 		if (intf_pending_clearable) {
1491 			err = regmap_update_bits(priv->map_reg,
1492 						 MCP251XFD_REG_INT,
1493 						 MCP251XFD_REG_INT_IF_MASK,
1494 						 ~intf_pending_clearable);
1495 			if (err)
1496 				goto out_fail;
1497 		}
1498 
1499 		if (intf_pending & MCP251XFD_REG_INT_MODIF) {
1500 			err = mcp251xfd_handle(priv, modif, &set_normal_mode);
1501 			if (err)
1502 				goto out_fail;
1503 		}
1504 
1505 		if (intf_pending & MCP251XFD_REG_INT_RXIF) {
1506 			err = mcp251xfd_handle(priv, rxif);
1507 			if (err)
1508 				goto out_fail;
1509 		}
1510 
1511 		if (intf_pending & MCP251XFD_REG_INT_TEFIF) {
1512 			err = mcp251xfd_handle(priv, tefif);
1513 			if (err)
1514 				goto out_fail;
1515 		}
1516 
1517 		if (intf_pending & MCP251XFD_REG_INT_RXOVIF) {
1518 			err = mcp251xfd_handle(priv, rxovif);
1519 			if (err)
1520 				goto out_fail;
1521 		}
1522 
1523 		if (intf_pending & MCP251XFD_REG_INT_TXATIF) {
1524 			err = mcp251xfd_handle(priv, txatif);
1525 			if (err)
1526 				goto out_fail;
1527 		}
1528 
1529 		if (intf_pending & MCP251XFD_REG_INT_IVMIF) {
1530 			err = mcp251xfd_handle(priv, ivmif);
1531 			if (err)
1532 				goto out_fail;
1533 		}
1534 
1535 		if (intf_pending & MCP251XFD_REG_INT_SERRIF) {
1536 			err = mcp251xfd_handle(priv, serrif);
1537 			if (err)
1538 				goto out_fail;
1539 		}
1540 
1541 		if (intf_pending & MCP251XFD_REG_INT_ECCIF) {
1542 			err = mcp251xfd_handle(priv, eccif, set_normal_mode);
1543 			if (err)
1544 				goto out_fail;
1545 		}
1546 
1547 		if (intf_pending & MCP251XFD_REG_INT_SPICRCIF) {
1548 			err = mcp251xfd_handle(priv, spicrcif);
1549 			if (err)
1550 				goto out_fail;
1551 		}
1552 
1553 		/* On the MCP2527FD and MCP2518FD, we don't get a
1554 		 * CERRIF IRQ on the transition TX ERROR_WARNING -> TX
1555 		 * ERROR_ACTIVE.
1556 		 */
1557 		if (intf_pending & MCP251XFD_REG_INT_CERRIF ||
1558 		    priv->can.state > CAN_STATE_ERROR_ACTIVE) {
1559 			err = mcp251xfd_handle(priv, cerrif);
1560 			if (err)
1561 				goto out_fail;
1562 
1563 			/* In Bus Off we completely shut down the
1564 			 * controller. Every subsequent register read
1565 			 * will read bogus data, and if
1566 			 * MCP251XFD_QUIRK_CRC_REG is enabled the CRC
1567 			 * check will fail, too. So leave IRQ handler
1568 			 * directly.
1569 			 */
1570 			if (priv->can.state == CAN_STATE_BUS_OFF) {
1571 				can_rx_offload_threaded_irq_finish(&priv->offload);
1572 				return IRQ_HANDLED;
1573 			}
1574 		}
1575 
1576 		handled = IRQ_HANDLED;
1577 	} while (1);
1578 
1579  out_fail:
1580 	can_rx_offload_threaded_irq_finish(&priv->offload);
1581 
1582 	netdev_err(priv->ndev, "IRQ handler returned %d (intf=0x%08x).\n",
1583 		   err, priv->regs_status.intf);
1584 	mcp251xfd_dump(priv);
1585 	mcp251xfd_chip_interrupts_disable(priv);
1586 	mcp251xfd_timestamp_stop(priv);
1587 
1588 	return handled;
1589 }
1590 
mcp251xfd_open(struct net_device * ndev)1591 static int mcp251xfd_open(struct net_device *ndev)
1592 {
1593 	struct mcp251xfd_priv *priv = netdev_priv(ndev);
1594 	const struct spi_device *spi = priv->spi;
1595 	int err;
1596 
1597 	err = open_candev(ndev);
1598 	if (err)
1599 		return err;
1600 
1601 	err = pm_runtime_resume_and_get(ndev->dev.parent);
1602 	if (err)
1603 		goto out_close_candev;
1604 
1605 	err = mcp251xfd_ring_alloc(priv);
1606 	if (err)
1607 		goto out_pm_runtime_put;
1608 
1609 	err = mcp251xfd_transceiver_enable(priv);
1610 	if (err)
1611 		goto out_mcp251xfd_ring_free;
1612 
1613 	err = mcp251xfd_chip_start(priv);
1614 	if (err)
1615 		goto out_transceiver_disable;
1616 
1617 	mcp251xfd_timestamp_init(priv);
1618 	clear_bit(MCP251XFD_FLAGS_DOWN, priv->flags);
1619 	can_rx_offload_enable(&priv->offload);
1620 
1621 	err = request_threaded_irq(spi->irq, NULL, mcp251xfd_irq,
1622 				   IRQF_SHARED | IRQF_ONESHOT,
1623 				   dev_name(&spi->dev), priv);
1624 	if (err)
1625 		goto out_can_rx_offload_disable;
1626 
1627 	err = mcp251xfd_chip_interrupts_enable(priv);
1628 	if (err)
1629 		goto out_free_irq;
1630 
1631 	netif_start_queue(ndev);
1632 
1633 	return 0;
1634 
1635  out_free_irq:
1636 	free_irq(spi->irq, priv);
1637  out_can_rx_offload_disable:
1638 	can_rx_offload_disable(&priv->offload);
1639 	set_bit(MCP251XFD_FLAGS_DOWN, priv->flags);
1640 	mcp251xfd_timestamp_stop(priv);
1641  out_transceiver_disable:
1642 	mcp251xfd_transceiver_disable(priv);
1643  out_mcp251xfd_ring_free:
1644 	mcp251xfd_ring_free(priv);
1645  out_pm_runtime_put:
1646 	mcp251xfd_chip_stop(priv, CAN_STATE_STOPPED);
1647 	pm_runtime_put(ndev->dev.parent);
1648  out_close_candev:
1649 	close_candev(ndev);
1650 
1651 	return err;
1652 }
1653 
mcp251xfd_stop(struct net_device * ndev)1654 static int mcp251xfd_stop(struct net_device *ndev)
1655 {
1656 	struct mcp251xfd_priv *priv = netdev_priv(ndev);
1657 
1658 	netif_stop_queue(ndev);
1659 	set_bit(MCP251XFD_FLAGS_DOWN, priv->flags);
1660 	hrtimer_cancel(&priv->rx_irq_timer);
1661 	hrtimer_cancel(&priv->tx_irq_timer);
1662 	mcp251xfd_chip_interrupts_disable(priv);
1663 	free_irq(ndev->irq, priv);
1664 	can_rx_offload_disable(&priv->offload);
1665 	mcp251xfd_timestamp_stop(priv);
1666 	mcp251xfd_chip_stop(priv, CAN_STATE_STOPPED);
1667 	mcp251xfd_transceiver_disable(priv);
1668 	mcp251xfd_ring_free(priv);
1669 	close_candev(ndev);
1670 
1671 	pm_runtime_put(ndev->dev.parent);
1672 
1673 	return 0;
1674 }
1675 
1676 static const struct net_device_ops mcp251xfd_netdev_ops = {
1677 	.ndo_open = mcp251xfd_open,
1678 	.ndo_stop = mcp251xfd_stop,
1679 	.ndo_start_xmit	= mcp251xfd_start_xmit,
1680 	.ndo_eth_ioctl = can_eth_ioctl_hwts,
1681 	.ndo_change_mtu = can_change_mtu,
1682 };
1683 
1684 static void
mcp251xfd_register_quirks(struct mcp251xfd_priv * priv)1685 mcp251xfd_register_quirks(struct mcp251xfd_priv *priv)
1686 {
1687 	const struct spi_device *spi = priv->spi;
1688 	const struct spi_controller *ctlr = spi->controller;
1689 
1690 	if (ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX)
1691 		priv->devtype_data.quirks |= MCP251XFD_QUIRK_HALF_DUPLEX;
1692 }
1693 
mcp251xfd_register_chip_detect(struct mcp251xfd_priv * priv)1694 static int mcp251xfd_register_chip_detect(struct mcp251xfd_priv *priv)
1695 {
1696 	const struct net_device *ndev = priv->ndev;
1697 	const struct mcp251xfd_devtype_data *devtype_data;
1698 	u32 osc;
1699 	int err;
1700 
1701 	/* The OSC_LPMEN is only supported on MCP2518FD and MCP251863,
1702 	 * so use it to autodetect the model.
1703 	 */
1704 	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_OSC,
1705 				 MCP251XFD_REG_OSC_LPMEN,
1706 				 MCP251XFD_REG_OSC_LPMEN);
1707 	if (err)
1708 		return err;
1709 
1710 	err = regmap_read(priv->map_reg, MCP251XFD_REG_OSC, &osc);
1711 	if (err)
1712 		return err;
1713 
1714 	if (osc & MCP251XFD_REG_OSC_LPMEN) {
1715 		/* We cannot distinguish between MCP2518FD and
1716 		 * MCP251863. If firmware specifies MCP251863, keep
1717 		 * it, otherwise set to MCP2518FD.
1718 		 */
1719 		if (mcp251xfd_is_251863(priv))
1720 			devtype_data = &mcp251xfd_devtype_data_mcp251863;
1721 		else
1722 			devtype_data = &mcp251xfd_devtype_data_mcp2518fd;
1723 	} else {
1724 		devtype_data = &mcp251xfd_devtype_data_mcp2517fd;
1725 	}
1726 
1727 	if (!mcp251xfd_is_251XFD(priv) &&
1728 	    priv->devtype_data.model != devtype_data->model) {
1729 		netdev_info(ndev,
1730 			    "Detected %s, but firmware specifies a %s. Fixing up.\n",
1731 			    __mcp251xfd_get_model_str(devtype_data->model),
1732 			    mcp251xfd_get_model_str(priv));
1733 	}
1734 	priv->devtype_data = *devtype_data;
1735 
1736 	/* We need to preserve the Half Duplex Quirk. */
1737 	mcp251xfd_register_quirks(priv);
1738 
1739 	/* Re-init regmap with quirks of detected model. */
1740 	return mcp251xfd_regmap_init(priv);
1741 }
1742 
mcp251xfd_register_check_rx_int(struct mcp251xfd_priv * priv)1743 static int mcp251xfd_register_check_rx_int(struct mcp251xfd_priv *priv)
1744 {
1745 	int err, rx_pending;
1746 
1747 	if (!priv->rx_int)
1748 		return 0;
1749 
1750 	err = mcp251xfd_chip_rx_int_enable(priv);
1751 	if (err)
1752 		return err;
1753 
1754 	/* Check if RX_INT is properly working. The RX_INT should not
1755 	 * be active after a softreset.
1756 	 */
1757 	rx_pending = gpiod_get_value_cansleep(priv->rx_int);
1758 
1759 	err = mcp251xfd_chip_rx_int_disable(priv);
1760 	if (err)
1761 		return err;
1762 
1763 	if (!rx_pending)
1764 		return 0;
1765 
1766 	netdev_info(priv->ndev,
1767 		    "RX_INT active after softreset, disabling RX_INT support.\n");
1768 	devm_gpiod_put(&priv->spi->dev, priv->rx_int);
1769 	priv->rx_int = NULL;
1770 
1771 	return 0;
1772 }
1773 
1774 static int
mcp251xfd_register_get_dev_id(const struct mcp251xfd_priv * priv,u32 * dev_id,u32 * effective_speed_hz_slow,u32 * effective_speed_hz_fast)1775 mcp251xfd_register_get_dev_id(const struct mcp251xfd_priv *priv, u32 *dev_id,
1776 			      u32 *effective_speed_hz_slow,
1777 			      u32 *effective_speed_hz_fast)
1778 {
1779 	struct mcp251xfd_map_buf_nocrc *buf_rx;
1780 	struct mcp251xfd_map_buf_nocrc *buf_tx;
1781 	struct spi_transfer xfer[2] = { };
1782 	int err;
1783 
1784 	buf_rx = kzalloc(sizeof(*buf_rx), GFP_KERNEL);
1785 	if (!buf_rx)
1786 		return -ENOMEM;
1787 
1788 	buf_tx = kzalloc(sizeof(*buf_tx), GFP_KERNEL);
1789 	if (!buf_tx) {
1790 		err = -ENOMEM;
1791 		goto out_kfree_buf_rx;
1792 	}
1793 
1794 	xfer[0].tx_buf = buf_tx;
1795 	xfer[0].len = sizeof(buf_tx->cmd);
1796 	xfer[0].speed_hz = priv->spi_max_speed_hz_slow;
1797 	xfer[1].rx_buf = buf_rx->data;
1798 	xfer[1].len = sizeof(*dev_id);
1799 	xfer[1].speed_hz = priv->spi_max_speed_hz_fast;
1800 
1801 	mcp251xfd_spi_cmd_read_nocrc(&buf_tx->cmd, MCP251XFD_REG_DEVID);
1802 
1803 	err = spi_sync_transfer(priv->spi, xfer, ARRAY_SIZE(xfer));
1804 	if (err)
1805 		goto out_kfree_buf_tx;
1806 
1807 	*dev_id = get_unaligned_le32(buf_rx->data);
1808 	*effective_speed_hz_slow = xfer[0].effective_speed_hz;
1809 	*effective_speed_hz_fast = xfer[1].effective_speed_hz;
1810 
1811  out_kfree_buf_tx:
1812 	kfree(buf_tx);
1813  out_kfree_buf_rx:
1814 	kfree(buf_rx);
1815 
1816 	return err;
1817 }
1818 
1819 #define MCP251XFD_QUIRK_ACTIVE(quirk) \
1820 	(priv->devtype_data.quirks & MCP251XFD_QUIRK_##quirk ? '+' : '-')
1821 
1822 static int
mcp251xfd_register_done(const struct mcp251xfd_priv * priv)1823 mcp251xfd_register_done(const struct mcp251xfd_priv *priv)
1824 {
1825 	u32 dev_id, effective_speed_hz_slow, effective_speed_hz_fast;
1826 	unsigned long clk_rate;
1827 	int err;
1828 
1829 	err = mcp251xfd_register_get_dev_id(priv, &dev_id,
1830 					    &effective_speed_hz_slow,
1831 					    &effective_speed_hz_fast);
1832 	if (err)
1833 		return err;
1834 
1835 	clk_rate = clk_get_rate(priv->clk);
1836 
1837 	netdev_info(priv->ndev,
1838 		    "%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",
1839 		    mcp251xfd_get_model_str(priv),
1840 		    FIELD_GET(MCP251XFD_REG_DEVID_ID_MASK, dev_id),
1841 		    FIELD_GET(MCP251XFD_REG_DEVID_REV_MASK, dev_id),
1842 		    priv->rx_int ? '+' : '-',
1843 		    priv->pll_enable ? '+' : '-',
1844 		    MCP251XFD_QUIRK_ACTIVE(MAB_NO_WARN),
1845 		    MCP251XFD_QUIRK_ACTIVE(CRC_REG),
1846 		    MCP251XFD_QUIRK_ACTIVE(CRC_RX),
1847 		    MCP251XFD_QUIRK_ACTIVE(CRC_TX),
1848 		    MCP251XFD_QUIRK_ACTIVE(ECC),
1849 		    MCP251XFD_QUIRK_ACTIVE(HALF_DUPLEX),
1850 		    clk_rate / 1000000,
1851 		    clk_rate % 1000000 / 1000 / 10,
1852 		    priv->can.clock.freq / 1000000,
1853 		    priv->can.clock.freq % 1000000 / 1000 / 10,
1854 		    priv->spi_max_speed_hz_orig / 1000000,
1855 		    priv->spi_max_speed_hz_orig % 1000000 / 1000 / 10,
1856 		    priv->spi_max_speed_hz_slow / 1000000,
1857 		    priv->spi_max_speed_hz_slow % 1000000 / 1000 / 10,
1858 		    effective_speed_hz_slow / 1000000,
1859 		    effective_speed_hz_slow % 1000000 / 1000 / 10,
1860 		    priv->spi_max_speed_hz_fast / 1000000,
1861 		    priv->spi_max_speed_hz_fast % 1000000 / 1000 / 10,
1862 		    effective_speed_hz_fast / 1000000,
1863 		    effective_speed_hz_fast % 1000000 / 1000 / 10);
1864 
1865 	return 0;
1866 }
1867 
mcp251xfd_register(struct mcp251xfd_priv * priv)1868 static int mcp251xfd_register(struct mcp251xfd_priv *priv)
1869 {
1870 	struct net_device *ndev = priv->ndev;
1871 	int err;
1872 
1873 	err = mcp251xfd_clks_and_vdd_enable(priv);
1874 	if (err)
1875 		return err;
1876 
1877 	pm_runtime_get_noresume(ndev->dev.parent);
1878 	err = pm_runtime_set_active(ndev->dev.parent);
1879 	if (err)
1880 		goto out_runtime_put_noidle;
1881 	pm_runtime_enable(ndev->dev.parent);
1882 
1883 	mcp251xfd_register_quirks(priv);
1884 
1885 	err = mcp251xfd_chip_softreset(priv);
1886 	if (err == -ENODEV)
1887 		goto out_runtime_disable;
1888 	if (err)
1889 		goto out_chip_sleep;
1890 
1891 	err = mcp251xfd_chip_clock_init(priv);
1892 	if (err == -ENODEV)
1893 		goto out_runtime_disable;
1894 	if (err)
1895 		goto out_chip_sleep;
1896 
1897 	err = mcp251xfd_register_chip_detect(priv);
1898 	if (err)
1899 		goto out_chip_sleep;
1900 
1901 	err = mcp251xfd_register_check_rx_int(priv);
1902 	if (err)
1903 		goto out_chip_sleep;
1904 
1905 	mcp251xfd_ethtool_init(priv);
1906 
1907 	err = register_candev(ndev);
1908 	if (err)
1909 		goto out_chip_sleep;
1910 
1911 	err = mcp251xfd_register_done(priv);
1912 	if (err)
1913 		goto out_unregister_candev;
1914 
1915 	/* Put controller into sleep mode and let pm_runtime_put()
1916 	 * disable the clocks and vdd. If CONFIG_PM is not enabled,
1917 	 * the clocks and vdd will stay powered.
1918 	 */
1919 	err = mcp251xfd_chip_sleep(priv);
1920 	if (err)
1921 		goto out_unregister_candev;
1922 
1923 	pm_runtime_put(ndev->dev.parent);
1924 
1925 	return 0;
1926 
1927  out_unregister_candev:
1928 	unregister_candev(ndev);
1929  out_chip_sleep:
1930 	mcp251xfd_chip_sleep(priv);
1931  out_runtime_disable:
1932 	pm_runtime_disable(ndev->dev.parent);
1933  out_runtime_put_noidle:
1934 	pm_runtime_put_noidle(ndev->dev.parent);
1935 	mcp251xfd_clks_and_vdd_disable(priv);
1936 
1937 	return err;
1938 }
1939 
mcp251xfd_unregister(struct mcp251xfd_priv * priv)1940 static inline void mcp251xfd_unregister(struct mcp251xfd_priv *priv)
1941 {
1942 	struct net_device *ndev	= priv->ndev;
1943 
1944 	unregister_candev(ndev);
1945 
1946 	if (pm_runtime_enabled(ndev->dev.parent))
1947 		pm_runtime_disable(ndev->dev.parent);
1948 	else
1949 		mcp251xfd_clks_and_vdd_disable(priv);
1950 }
1951 
1952 static const struct of_device_id mcp251xfd_of_match[] = {
1953 	{
1954 		.compatible = "microchip,mcp2517fd",
1955 		.data = &mcp251xfd_devtype_data_mcp2517fd,
1956 	}, {
1957 		.compatible = "microchip,mcp2518fd",
1958 		.data = &mcp251xfd_devtype_data_mcp2518fd,
1959 	}, {
1960 		.compatible = "microchip,mcp251863",
1961 		.data = &mcp251xfd_devtype_data_mcp251863,
1962 	}, {
1963 		.compatible = "microchip,mcp251xfd",
1964 		.data = &mcp251xfd_devtype_data_mcp251xfd,
1965 	}, {
1966 		/* sentinel */
1967 	},
1968 };
1969 MODULE_DEVICE_TABLE(of, mcp251xfd_of_match);
1970 
1971 static const struct spi_device_id mcp251xfd_id_table[] = {
1972 	{
1973 		.name = "mcp2517fd",
1974 		.driver_data = (kernel_ulong_t)&mcp251xfd_devtype_data_mcp2517fd,
1975 	}, {
1976 		.name = "mcp2518fd",
1977 		.driver_data = (kernel_ulong_t)&mcp251xfd_devtype_data_mcp2518fd,
1978 	}, {
1979 		.name = "mcp251863",
1980 		.driver_data = (kernel_ulong_t)&mcp251xfd_devtype_data_mcp251863,
1981 	}, {
1982 		.name = "mcp251xfd",
1983 		.driver_data = (kernel_ulong_t)&mcp251xfd_devtype_data_mcp251xfd,
1984 	}, {
1985 		/* sentinel */
1986 	},
1987 };
1988 MODULE_DEVICE_TABLE(spi, mcp251xfd_id_table);
1989 
mcp251xfd_probe(struct spi_device * spi)1990 static int mcp251xfd_probe(struct spi_device *spi)
1991 {
1992 	const void *match;
1993 	struct net_device *ndev;
1994 	struct mcp251xfd_priv *priv;
1995 	struct gpio_desc *rx_int;
1996 	struct regulator *reg_vdd, *reg_xceiver;
1997 	struct clk *clk;
1998 	bool pll_enable = false;
1999 	u32 freq = 0;
2000 	int err;
2001 
2002 	if (!spi->irq)
2003 		return dev_err_probe(&spi->dev, -ENXIO,
2004 				     "No IRQ specified (maybe node \"interrupts-extended\" in DT missing)!\n");
2005 
2006 	rx_int = devm_gpiod_get_optional(&spi->dev, "microchip,rx-int",
2007 					 GPIOD_IN);
2008 	if (IS_ERR(rx_int))
2009 		return dev_err_probe(&spi->dev, PTR_ERR(rx_int),
2010 				     "Failed to get RX-INT!\n");
2011 
2012 	reg_vdd = devm_regulator_get_optional(&spi->dev, "vdd");
2013 	if (PTR_ERR(reg_vdd) == -ENODEV)
2014 		reg_vdd = NULL;
2015 	else if (IS_ERR(reg_vdd))
2016 		return dev_err_probe(&spi->dev, PTR_ERR(reg_vdd),
2017 				     "Failed to get VDD regulator!\n");
2018 
2019 	reg_xceiver = devm_regulator_get_optional(&spi->dev, "xceiver");
2020 	if (PTR_ERR(reg_xceiver) == -ENODEV)
2021 		reg_xceiver = NULL;
2022 	else if (IS_ERR(reg_xceiver))
2023 		return dev_err_probe(&spi->dev, PTR_ERR(reg_xceiver),
2024 				     "Failed to get Transceiver regulator!\n");
2025 
2026 	clk = devm_clk_get_optional(&spi->dev, NULL);
2027 	if (IS_ERR(clk))
2028 		return dev_err_probe(&spi->dev, PTR_ERR(clk),
2029 				     "Failed to get Oscillator (clock)!\n");
2030 	if (clk) {
2031 		freq = clk_get_rate(clk);
2032 	} else {
2033 		err = device_property_read_u32(&spi->dev, "clock-frequency",
2034 					       &freq);
2035 		if (err)
2036 			return dev_err_probe(&spi->dev, err,
2037 					     "Failed to get clock-frequency!\n");
2038 	}
2039 
2040 	/* Sanity check */
2041 	if (freq < MCP251XFD_SYSCLOCK_HZ_MIN ||
2042 	    freq > MCP251XFD_SYSCLOCK_HZ_MAX) {
2043 		dev_err(&spi->dev,
2044 			"Oscillator frequency (%u Hz) is too low or high.\n",
2045 			freq);
2046 		return -ERANGE;
2047 	}
2048 
2049 	if (freq <= MCP251XFD_SYSCLOCK_HZ_MAX / MCP251XFD_OSC_PLL_MULTIPLIER)
2050 		pll_enable = true;
2051 
2052 	ndev = alloc_candev(sizeof(struct mcp251xfd_priv),
2053 			    MCP251XFD_TX_OBJ_NUM_MAX);
2054 	if (!ndev)
2055 		return -ENOMEM;
2056 
2057 	SET_NETDEV_DEV(ndev, &spi->dev);
2058 
2059 	ndev->netdev_ops = &mcp251xfd_netdev_ops;
2060 	ndev->irq = spi->irq;
2061 	ndev->flags |= IFF_ECHO;
2062 
2063 	priv = netdev_priv(ndev);
2064 	spi_set_drvdata(spi, priv);
2065 	priv->can.clock.freq = freq;
2066 	if (pll_enable)
2067 		priv->can.clock.freq *= MCP251XFD_OSC_PLL_MULTIPLIER;
2068 	priv->can.do_set_mode = mcp251xfd_set_mode;
2069 	priv->can.do_get_berr_counter = mcp251xfd_get_berr_counter;
2070 	priv->can.bittiming_const = &mcp251xfd_bittiming_const;
2071 	priv->can.data_bittiming_const = &mcp251xfd_data_bittiming_const;
2072 	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
2073 		CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_BERR_REPORTING |
2074 		CAN_CTRLMODE_FD | CAN_CTRLMODE_FD_NON_ISO |
2075 		CAN_CTRLMODE_CC_LEN8_DLC;
2076 	set_bit(MCP251XFD_FLAGS_DOWN, priv->flags);
2077 	priv->ndev = ndev;
2078 	priv->spi = spi;
2079 	priv->rx_int = rx_int;
2080 	priv->clk = clk;
2081 	priv->pll_enable = pll_enable;
2082 	priv->reg_vdd = reg_vdd;
2083 	priv->reg_xceiver = reg_xceiver;
2084 
2085 	match = device_get_match_data(&spi->dev);
2086 	if (match)
2087 		priv->devtype_data = *(struct mcp251xfd_devtype_data *)match;
2088 	else
2089 		priv->devtype_data = *(struct mcp251xfd_devtype_data *)
2090 			spi_get_device_id(spi)->driver_data;
2091 
2092 	/* Errata Reference:
2093 	 * mcp2517fd: DS80000792C 5., mcp2518fd: DS80000789C 4.
2094 	 *
2095 	 * The SPI can write corrupted data to the RAM at fast SPI
2096 	 * speeds:
2097 	 *
2098 	 * Simultaneous activity on the CAN bus while writing data to
2099 	 * RAM via the SPI interface, with high SCK frequency, can
2100 	 * lead to corrupted data being written to RAM.
2101 	 *
2102 	 * Fix/Work Around:
2103 	 * Ensure that FSCK is less than or equal to 0.85 *
2104 	 * (FSYSCLK/2).
2105 	 *
2106 	 * Known good combinations are:
2107 	 *
2108 	 * MCP	ext-clk	SoC			SPI			SPI-clk		max-clk	parent-clk	config
2109 	 *
2110 	 * 2518	20 MHz	allwinner,sun8i-h3	allwinner,sun8i-h3-spi	 8333333 Hz	 83.33%	600000000 Hz	assigned-clocks = <&ccu CLK_SPIx>
2111 	 * 2518	40 MHz	allwinner,sun8i-h3	allwinner,sun8i-h3-spi	16666667 Hz	 83.33%	600000000 Hz	assigned-clocks = <&ccu CLK_SPIx>
2112 	 * 2517	40 MHz	atmel,sama5d27		atmel,at91rm9200-spi	16400000 Hz	 82.00%	 82000000 Hz	default
2113 	 * 2518	40 MHz	atmel,sama5d27		atmel,at91rm9200-spi	16400000 Hz	 82.00%	 82000000 Hz	default
2114 	 * 2518	40 MHz	fsl,imx6dl		fsl,imx51-ecspi		15000000 Hz	 75.00%	 30000000 Hz	default
2115 	 * 2517	20 MHz	fsl,imx8mm		fsl,imx51-ecspi		 8333333 Hz	 83.33%	 16666667 Hz	assigned-clocks = <&clk IMX8MM_CLK_ECSPIx_ROOT>
2116 	 *
2117 	 */
2118 	priv->spi_max_speed_hz_orig = spi->max_speed_hz;
2119 	priv->spi_max_speed_hz_slow = min(spi->max_speed_hz,
2120 					  freq / 2 / 1000 * 850);
2121 	if (priv->pll_enable)
2122 		priv->spi_max_speed_hz_fast = min(spi->max_speed_hz,
2123 						  freq *
2124 						  MCP251XFD_OSC_PLL_MULTIPLIER /
2125 						  2 / 1000 * 850);
2126 	else
2127 		priv->spi_max_speed_hz_fast = priv->spi_max_speed_hz_slow;
2128 	spi->max_speed_hz = priv->spi_max_speed_hz_slow;
2129 	spi->bits_per_word = 8;
2130 	spi->rt = true;
2131 	err = spi_setup(spi);
2132 	if (err)
2133 		goto out_free_candev;
2134 
2135 	err = mcp251xfd_regmap_init(priv);
2136 	if (err)
2137 		goto out_free_candev;
2138 
2139 	err = can_rx_offload_add_manual(ndev, &priv->offload,
2140 					MCP251XFD_NAPI_WEIGHT);
2141 	if (err)
2142 		goto out_free_candev;
2143 
2144 	err = mcp251xfd_register(priv);
2145 	if (err) {
2146 		dev_err_probe(&spi->dev, err, "Failed to detect %s.\n",
2147 			      mcp251xfd_get_model_str(priv));
2148 		goto out_can_rx_offload_del;
2149 	}
2150 
2151 	return 0;
2152 
2153  out_can_rx_offload_del:
2154 	can_rx_offload_del(&priv->offload);
2155  out_free_candev:
2156 	spi->max_speed_hz = priv->spi_max_speed_hz_orig;
2157 
2158 	free_candev(ndev);
2159 
2160 	return err;
2161 }
2162 
mcp251xfd_remove(struct spi_device * spi)2163 static void mcp251xfd_remove(struct spi_device *spi)
2164 {
2165 	struct mcp251xfd_priv *priv = spi_get_drvdata(spi);
2166 	struct net_device *ndev = priv->ndev;
2167 
2168 	can_rx_offload_del(&priv->offload);
2169 	mcp251xfd_unregister(priv);
2170 	spi->max_speed_hz = priv->spi_max_speed_hz_orig;
2171 	free_candev(ndev);
2172 }
2173 
mcp251xfd_runtime_suspend(struct device * device)2174 static int __maybe_unused mcp251xfd_runtime_suspend(struct device *device)
2175 {
2176 	const struct mcp251xfd_priv *priv = dev_get_drvdata(device);
2177 
2178 	return mcp251xfd_clks_and_vdd_disable(priv);
2179 }
2180 
mcp251xfd_runtime_resume(struct device * device)2181 static int __maybe_unused mcp251xfd_runtime_resume(struct device *device)
2182 {
2183 	const struct mcp251xfd_priv *priv = dev_get_drvdata(device);
2184 
2185 	return mcp251xfd_clks_and_vdd_enable(priv);
2186 }
2187 
2188 static const struct dev_pm_ops mcp251xfd_pm_ops = {
2189 	SET_RUNTIME_PM_OPS(mcp251xfd_runtime_suspend,
2190 			   mcp251xfd_runtime_resume, NULL)
2191 };
2192 
2193 static struct spi_driver mcp251xfd_driver = {
2194 	.driver = {
2195 		.name = DEVICE_NAME,
2196 		.pm = &mcp251xfd_pm_ops,
2197 		.of_match_table = mcp251xfd_of_match,
2198 	},
2199 	.probe = mcp251xfd_probe,
2200 	.remove = mcp251xfd_remove,
2201 	.id_table = mcp251xfd_id_table,
2202 };
2203 module_spi_driver(mcp251xfd_driver);
2204 
2205 MODULE_AUTHOR("Marc Kleine-Budde <mkl@pengutronix.de>");
2206 MODULE_DESCRIPTION("Microchip MCP251xFD Family CAN controller driver");
2207 MODULE_LICENSE("GPL v2");
2208