xref: /openbmc/linux/drivers/net/can/spi/mcp251x.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* CAN bus driver for Microchip 251x/25625 CAN Controller with SPI Interface
3  *
4  * MCP2510 support and bug fixes by Christian Pellegrin
5  * <chripell@evolware.org>
6  *
7  * Copyright 2009 Christian Pellegrin EVOL S.r.l.
8  *
9  * Copyright 2007 Raymarine UK, Ltd. All Rights Reserved.
10  * Written under contract by:
11  *   Chris Elston, Katalix Systems, Ltd.
12  *
13  * Based on Microchip MCP251x CAN controller driver written by
14  * David Vrabel, Copyright 2006 Arcom Control Systems Ltd.
15  *
16  * Based on CAN bus driver for the CCAN controller written by
17  * - Sascha Hauer, Marc Kleine-Budde, Pengutronix
18  * - Simon Kallweit, intefo AG
19  * Copyright 2007
20  */
21 
22 #include <linux/can/core.h>
23 #include <linux/can/dev.h>
24 #include <linux/can/led.h>
25 #include <linux/clk.h>
26 #include <linux/completion.h>
27 #include <linux/delay.h>
28 #include <linux/device.h>
29 #include <linux/freezer.h>
30 #include <linux/interrupt.h>
31 #include <linux/io.h>
32 #include <linux/kernel.h>
33 #include <linux/module.h>
34 #include <linux/netdevice.h>
35 #include <linux/property.h>
36 #include <linux/platform_device.h>
37 #include <linux/slab.h>
38 #include <linux/spi/spi.h>
39 #include <linux/uaccess.h>
40 #include <linux/regulator/consumer.h>
41 
42 /* SPI interface instruction set */
43 #define INSTRUCTION_WRITE	0x02
44 #define INSTRUCTION_READ	0x03
45 #define INSTRUCTION_BIT_MODIFY	0x05
46 #define INSTRUCTION_LOAD_TXB(n)	(0x40 + 2 * (n))
47 #define INSTRUCTION_READ_RXB(n)	(((n) == 0) ? 0x90 : 0x94)
48 #define INSTRUCTION_RESET	0xC0
49 #define RTS_TXB0		0x01
50 #define RTS_TXB1		0x02
51 #define RTS_TXB2		0x04
52 #define INSTRUCTION_RTS(n)	(0x80 | ((n) & 0x07))
53 
54 /* MPC251x registers */
55 #define CANSTAT	      0x0e
56 #define CANCTRL	      0x0f
57 #  define CANCTRL_REQOP_MASK	    0xe0
58 #  define CANCTRL_REQOP_CONF	    0x80
59 #  define CANCTRL_REQOP_LISTEN_ONLY 0x60
60 #  define CANCTRL_REQOP_LOOPBACK    0x40
61 #  define CANCTRL_REQOP_SLEEP	    0x20
62 #  define CANCTRL_REQOP_NORMAL	    0x00
63 #  define CANCTRL_OSM		    0x08
64 #  define CANCTRL_ABAT		    0x10
65 #define TEC	      0x1c
66 #define REC	      0x1d
67 #define CNF1	      0x2a
68 #  define CNF1_SJW_SHIFT   6
69 #define CNF2	      0x29
70 #  define CNF2_BTLMODE	   0x80
71 #  define CNF2_SAM         0x40
72 #  define CNF2_PS1_SHIFT   3
73 #define CNF3	      0x28
74 #  define CNF3_SOF	   0x08
75 #  define CNF3_WAKFIL	   0x04
76 #  define CNF3_PHSEG2_MASK 0x07
77 #define CANINTE	      0x2b
78 #  define CANINTE_MERRE 0x80
79 #  define CANINTE_WAKIE 0x40
80 #  define CANINTE_ERRIE 0x20
81 #  define CANINTE_TX2IE 0x10
82 #  define CANINTE_TX1IE 0x08
83 #  define CANINTE_TX0IE 0x04
84 #  define CANINTE_RX1IE 0x02
85 #  define CANINTE_RX0IE 0x01
86 #define CANINTF	      0x2c
87 #  define CANINTF_MERRF 0x80
88 #  define CANINTF_WAKIF 0x40
89 #  define CANINTF_ERRIF 0x20
90 #  define CANINTF_TX2IF 0x10
91 #  define CANINTF_TX1IF 0x08
92 #  define CANINTF_TX0IF 0x04
93 #  define CANINTF_RX1IF 0x02
94 #  define CANINTF_RX0IF 0x01
95 #  define CANINTF_RX (CANINTF_RX0IF | CANINTF_RX1IF)
96 #  define CANINTF_TX (CANINTF_TX2IF | CANINTF_TX1IF | CANINTF_TX0IF)
97 #  define CANINTF_ERR (CANINTF_ERRIF)
98 #define EFLG	      0x2d
99 #  define EFLG_EWARN	0x01
100 #  define EFLG_RXWAR	0x02
101 #  define EFLG_TXWAR	0x04
102 #  define EFLG_RXEP	0x08
103 #  define EFLG_TXEP	0x10
104 #  define EFLG_TXBO	0x20
105 #  define EFLG_RX0OVR	0x40
106 #  define EFLG_RX1OVR	0x80
107 #define TXBCTRL(n)  (((n) * 0x10) + 0x30 + TXBCTRL_OFF)
108 #  define TXBCTRL_ABTF	0x40
109 #  define TXBCTRL_MLOA	0x20
110 #  define TXBCTRL_TXERR 0x10
111 #  define TXBCTRL_TXREQ 0x08
112 #define TXBSIDH(n)  (((n) * 0x10) + 0x30 + TXBSIDH_OFF)
113 #  define SIDH_SHIFT    3
114 #define TXBSIDL(n)  (((n) * 0x10) + 0x30 + TXBSIDL_OFF)
115 #  define SIDL_SID_MASK    7
116 #  define SIDL_SID_SHIFT   5
117 #  define SIDL_EXIDE_SHIFT 3
118 #  define SIDL_EID_SHIFT   16
119 #  define SIDL_EID_MASK    3
120 #define TXBEID8(n)  (((n) * 0x10) + 0x30 + TXBEID8_OFF)
121 #define TXBEID0(n)  (((n) * 0x10) + 0x30 + TXBEID0_OFF)
122 #define TXBDLC(n)   (((n) * 0x10) + 0x30 + TXBDLC_OFF)
123 #  define DLC_RTR_SHIFT    6
124 #define TXBCTRL_OFF 0
125 #define TXBSIDH_OFF 1
126 #define TXBSIDL_OFF 2
127 #define TXBEID8_OFF 3
128 #define TXBEID0_OFF 4
129 #define TXBDLC_OFF  5
130 #define TXBDAT_OFF  6
131 #define RXBCTRL(n)  (((n) * 0x10) + 0x60 + RXBCTRL_OFF)
132 #  define RXBCTRL_BUKT	0x04
133 #  define RXBCTRL_RXM0	0x20
134 #  define RXBCTRL_RXM1	0x40
135 #define RXBSIDH(n)  (((n) * 0x10) + 0x60 + RXBSIDH_OFF)
136 #  define RXBSIDH_SHIFT 3
137 #define RXBSIDL(n)  (((n) * 0x10) + 0x60 + RXBSIDL_OFF)
138 #  define RXBSIDL_IDE   0x08
139 #  define RXBSIDL_SRR   0x10
140 #  define RXBSIDL_EID   3
141 #  define RXBSIDL_SHIFT 5
142 #define RXBEID8(n)  (((n) * 0x10) + 0x60 + RXBEID8_OFF)
143 #define RXBEID0(n)  (((n) * 0x10) + 0x60 + RXBEID0_OFF)
144 #define RXBDLC(n)   (((n) * 0x10) + 0x60 + RXBDLC_OFF)
145 #  define RXBDLC_LEN_MASK  0x0f
146 #  define RXBDLC_RTR       0x40
147 #define RXBCTRL_OFF 0
148 #define RXBSIDH_OFF 1
149 #define RXBSIDL_OFF 2
150 #define RXBEID8_OFF 3
151 #define RXBEID0_OFF 4
152 #define RXBDLC_OFF  5
153 #define RXBDAT_OFF  6
154 #define RXFSID(n) ((n < 3) ? 0 : 4)
155 #define RXFSIDH(n) ((n) * 4 + RXFSID(n))
156 #define RXFSIDL(n) ((n) * 4 + 1 + RXFSID(n))
157 #define RXFEID8(n) ((n) * 4 + 2 + RXFSID(n))
158 #define RXFEID0(n) ((n) * 4 + 3 + RXFSID(n))
159 #define RXMSIDH(n) ((n) * 4 + 0x20)
160 #define RXMSIDL(n) ((n) * 4 + 0x21)
161 #define RXMEID8(n) ((n) * 4 + 0x22)
162 #define RXMEID0(n) ((n) * 4 + 0x23)
163 
164 #define GET_BYTE(val, byte)			\
165 	(((val) >> ((byte) * 8)) & 0xff)
166 #define SET_BYTE(val, byte)			\
167 	(((val) & 0xff) << ((byte) * 8))
168 
169 /* Buffer size required for the largest SPI transfer (i.e., reading a
170  * frame)
171  */
172 #define CAN_FRAME_MAX_DATA_LEN	8
173 #define SPI_TRANSFER_BUF_LEN	(6 + CAN_FRAME_MAX_DATA_LEN)
174 #define CAN_FRAME_MAX_BITS	128
175 
176 #define TX_ECHO_SKB_MAX	1
177 
178 #define MCP251X_OST_DELAY_MS	(5)
179 
180 #define DEVICE_NAME "mcp251x"
181 
182 static const struct can_bittiming_const mcp251x_bittiming_const = {
183 	.name = DEVICE_NAME,
184 	.tseg1_min = 3,
185 	.tseg1_max = 16,
186 	.tseg2_min = 2,
187 	.tseg2_max = 8,
188 	.sjw_max = 4,
189 	.brp_min = 1,
190 	.brp_max = 64,
191 	.brp_inc = 1,
192 };
193 
194 enum mcp251x_model {
195 	CAN_MCP251X_MCP2510	= 0x2510,
196 	CAN_MCP251X_MCP2515	= 0x2515,
197 	CAN_MCP251X_MCP25625	= 0x25625,
198 };
199 
200 struct mcp251x_priv {
201 	struct can_priv	   can;
202 	struct net_device *net;
203 	struct spi_device *spi;
204 	enum mcp251x_model model;
205 
206 	struct mutex mcp_lock; /* SPI device lock */
207 
208 	u8 *spi_tx_buf;
209 	u8 *spi_rx_buf;
210 
211 	struct sk_buff *tx_skb;
212 	int tx_len;
213 
214 	struct workqueue_struct *wq;
215 	struct work_struct tx_work;
216 	struct work_struct restart_work;
217 
218 	int force_quit;
219 	int after_suspend;
220 #define AFTER_SUSPEND_UP 1
221 #define AFTER_SUSPEND_DOWN 2
222 #define AFTER_SUSPEND_POWER 4
223 #define AFTER_SUSPEND_RESTART 8
224 	int restart_tx;
225 	struct regulator *power;
226 	struct regulator *transceiver;
227 	struct clk *clk;
228 };
229 
230 #define MCP251X_IS(_model) \
231 static inline int mcp251x_is_##_model(struct spi_device *spi) \
232 { \
233 	struct mcp251x_priv *priv = spi_get_drvdata(spi); \
234 	return priv->model == CAN_MCP251X_MCP##_model; \
235 }
236 
237 MCP251X_IS(2510);
238 
239 static void mcp251x_clean(struct net_device *net)
240 {
241 	struct mcp251x_priv *priv = netdev_priv(net);
242 
243 	if (priv->tx_skb || priv->tx_len)
244 		net->stats.tx_errors++;
245 	dev_kfree_skb(priv->tx_skb);
246 	if (priv->tx_len)
247 		can_free_echo_skb(priv->net, 0);
248 	priv->tx_skb = NULL;
249 	priv->tx_len = 0;
250 }
251 
252 /* Note about handling of error return of mcp251x_spi_trans: accessing
253  * registers via SPI is not really different conceptually than using
254  * normal I/O assembler instructions, although it's much more
255  * complicated from a practical POV. So it's not advisable to always
256  * check the return value of this function. Imagine that every
257  * read{b,l}, write{b,l} and friends would be bracketed in "if ( < 0)
258  * error();", it would be a great mess (well there are some situation
259  * when exception handling C++ like could be useful after all). So we
260  * just check that transfers are OK at the beginning of our
261  * conversation with the chip and to avoid doing really nasty things
262  * (like injecting bogus packets in the network stack).
263  */
264 static int mcp251x_spi_trans(struct spi_device *spi, int len)
265 {
266 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
267 	struct spi_transfer t = {
268 		.tx_buf = priv->spi_tx_buf,
269 		.rx_buf = priv->spi_rx_buf,
270 		.len = len,
271 		.cs_change = 0,
272 	};
273 	struct spi_message m;
274 	int ret;
275 
276 	spi_message_init(&m);
277 	spi_message_add_tail(&t, &m);
278 
279 	ret = spi_sync(spi, &m);
280 	if (ret)
281 		dev_err(&spi->dev, "spi transfer failed: ret = %d\n", ret);
282 	return ret;
283 }
284 
285 static u8 mcp251x_read_reg(struct spi_device *spi, u8 reg)
286 {
287 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
288 	u8 val = 0;
289 
290 	priv->spi_tx_buf[0] = INSTRUCTION_READ;
291 	priv->spi_tx_buf[1] = reg;
292 
293 	mcp251x_spi_trans(spi, 3);
294 	val = priv->spi_rx_buf[2];
295 
296 	return val;
297 }
298 
299 static void mcp251x_read_2regs(struct spi_device *spi, u8 reg, u8 *v1, u8 *v2)
300 {
301 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
302 
303 	priv->spi_tx_buf[0] = INSTRUCTION_READ;
304 	priv->spi_tx_buf[1] = reg;
305 
306 	mcp251x_spi_trans(spi, 4);
307 
308 	*v1 = priv->spi_rx_buf[2];
309 	*v2 = priv->spi_rx_buf[3];
310 }
311 
312 static void mcp251x_write_reg(struct spi_device *spi, u8 reg, u8 val)
313 {
314 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
315 
316 	priv->spi_tx_buf[0] = INSTRUCTION_WRITE;
317 	priv->spi_tx_buf[1] = reg;
318 	priv->spi_tx_buf[2] = val;
319 
320 	mcp251x_spi_trans(spi, 3);
321 }
322 
323 static void mcp251x_write_2regs(struct spi_device *spi, u8 reg, u8 v1, u8 v2)
324 {
325 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
326 
327 	priv->spi_tx_buf[0] = INSTRUCTION_WRITE;
328 	priv->spi_tx_buf[1] = reg;
329 	priv->spi_tx_buf[2] = v1;
330 	priv->spi_tx_buf[3] = v2;
331 
332 	mcp251x_spi_trans(spi, 4);
333 }
334 
335 static void mcp251x_write_bits(struct spi_device *spi, u8 reg,
336 			       u8 mask, u8 val)
337 {
338 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
339 
340 	priv->spi_tx_buf[0] = INSTRUCTION_BIT_MODIFY;
341 	priv->spi_tx_buf[1] = reg;
342 	priv->spi_tx_buf[2] = mask;
343 	priv->spi_tx_buf[3] = val;
344 
345 	mcp251x_spi_trans(spi, 4);
346 }
347 
348 static void mcp251x_hw_tx_frame(struct spi_device *spi, u8 *buf,
349 				int len, int tx_buf_idx)
350 {
351 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
352 
353 	if (mcp251x_is_2510(spi)) {
354 		int i;
355 
356 		for (i = 1; i < TXBDAT_OFF + len; i++)
357 			mcp251x_write_reg(spi, TXBCTRL(tx_buf_idx) + i,
358 					  buf[i]);
359 	} else {
360 		memcpy(priv->spi_tx_buf, buf, TXBDAT_OFF + len);
361 		mcp251x_spi_trans(spi, TXBDAT_OFF + len);
362 	}
363 }
364 
365 static void mcp251x_hw_tx(struct spi_device *spi, struct can_frame *frame,
366 			  int tx_buf_idx)
367 {
368 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
369 	u32 sid, eid, exide, rtr;
370 	u8 buf[SPI_TRANSFER_BUF_LEN];
371 
372 	exide = (frame->can_id & CAN_EFF_FLAG) ? 1 : 0; /* Extended ID Enable */
373 	if (exide)
374 		sid = (frame->can_id & CAN_EFF_MASK) >> 18;
375 	else
376 		sid = frame->can_id & CAN_SFF_MASK; /* Standard ID */
377 	eid = frame->can_id & CAN_EFF_MASK; /* Extended ID */
378 	rtr = (frame->can_id & CAN_RTR_FLAG) ? 1 : 0; /* Remote transmission */
379 
380 	buf[TXBCTRL_OFF] = INSTRUCTION_LOAD_TXB(tx_buf_idx);
381 	buf[TXBSIDH_OFF] = sid >> SIDH_SHIFT;
382 	buf[TXBSIDL_OFF] = ((sid & SIDL_SID_MASK) << SIDL_SID_SHIFT) |
383 		(exide << SIDL_EXIDE_SHIFT) |
384 		((eid >> SIDL_EID_SHIFT) & SIDL_EID_MASK);
385 	buf[TXBEID8_OFF] = GET_BYTE(eid, 1);
386 	buf[TXBEID0_OFF] = GET_BYTE(eid, 0);
387 	buf[TXBDLC_OFF] = (rtr << DLC_RTR_SHIFT) | frame->can_dlc;
388 	memcpy(buf + TXBDAT_OFF, frame->data, frame->can_dlc);
389 	mcp251x_hw_tx_frame(spi, buf, frame->can_dlc, tx_buf_idx);
390 
391 	/* use INSTRUCTION_RTS, to avoid "repeated frame problem" */
392 	priv->spi_tx_buf[0] = INSTRUCTION_RTS(1 << tx_buf_idx);
393 	mcp251x_spi_trans(priv->spi, 1);
394 }
395 
396 static void mcp251x_hw_rx_frame(struct spi_device *spi, u8 *buf,
397 				int buf_idx)
398 {
399 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
400 
401 	if (mcp251x_is_2510(spi)) {
402 		int i, len;
403 
404 		for (i = 1; i < RXBDAT_OFF; i++)
405 			buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i);
406 
407 		len = get_can_dlc(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK);
408 		for (; i < (RXBDAT_OFF + len); i++)
409 			buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i);
410 	} else {
411 		priv->spi_tx_buf[RXBCTRL_OFF] = INSTRUCTION_READ_RXB(buf_idx);
412 		mcp251x_spi_trans(spi, SPI_TRANSFER_BUF_LEN);
413 		memcpy(buf, priv->spi_rx_buf, SPI_TRANSFER_BUF_LEN);
414 	}
415 }
416 
417 static void mcp251x_hw_rx(struct spi_device *spi, int buf_idx)
418 {
419 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
420 	struct sk_buff *skb;
421 	struct can_frame *frame;
422 	u8 buf[SPI_TRANSFER_BUF_LEN];
423 
424 	skb = alloc_can_skb(priv->net, &frame);
425 	if (!skb) {
426 		dev_err(&spi->dev, "cannot allocate RX skb\n");
427 		priv->net->stats.rx_dropped++;
428 		return;
429 	}
430 
431 	mcp251x_hw_rx_frame(spi, buf, buf_idx);
432 	if (buf[RXBSIDL_OFF] & RXBSIDL_IDE) {
433 		/* Extended ID format */
434 		frame->can_id = CAN_EFF_FLAG;
435 		frame->can_id |=
436 			/* Extended ID part */
437 			SET_BYTE(buf[RXBSIDL_OFF] & RXBSIDL_EID, 2) |
438 			SET_BYTE(buf[RXBEID8_OFF], 1) |
439 			SET_BYTE(buf[RXBEID0_OFF], 0) |
440 			/* Standard ID part */
441 			(((buf[RXBSIDH_OFF] << RXBSIDH_SHIFT) |
442 			  (buf[RXBSIDL_OFF] >> RXBSIDL_SHIFT)) << 18);
443 		/* Remote transmission request */
444 		if (buf[RXBDLC_OFF] & RXBDLC_RTR)
445 			frame->can_id |= CAN_RTR_FLAG;
446 	} else {
447 		/* Standard ID format */
448 		frame->can_id =
449 			(buf[RXBSIDH_OFF] << RXBSIDH_SHIFT) |
450 			(buf[RXBSIDL_OFF] >> RXBSIDL_SHIFT);
451 		if (buf[RXBSIDL_OFF] & RXBSIDL_SRR)
452 			frame->can_id |= CAN_RTR_FLAG;
453 	}
454 	/* Data length */
455 	frame->can_dlc = get_can_dlc(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK);
456 	memcpy(frame->data, buf + RXBDAT_OFF, frame->can_dlc);
457 
458 	priv->net->stats.rx_packets++;
459 	priv->net->stats.rx_bytes += frame->can_dlc;
460 
461 	can_led_event(priv->net, CAN_LED_EVENT_RX);
462 
463 	netif_rx_ni(skb);
464 }
465 
466 static void mcp251x_hw_sleep(struct spi_device *spi)
467 {
468 	mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_SLEEP);
469 }
470 
471 /* May only be called when device is sleeping! */
472 static int mcp251x_hw_wake(struct spi_device *spi)
473 {
474 	unsigned long timeout;
475 
476 	/* Force wakeup interrupt to wake device, but don't execute IST */
477 	disable_irq(spi->irq);
478 	mcp251x_write_2regs(spi, CANINTE, CANINTE_WAKIE, CANINTF_WAKIF);
479 
480 	/* Wait for oscillator startup timer after wake up */
481 	mdelay(MCP251X_OST_DELAY_MS);
482 
483 	/* Put device into config mode */
484 	mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_CONF);
485 
486 	/* Wait for the device to enter config mode */
487 	timeout = jiffies + HZ;
488 	while ((mcp251x_read_reg(spi, CANSTAT) & CANCTRL_REQOP_MASK) !=
489 			CANCTRL_REQOP_CONF) {
490 		schedule();
491 		if (time_after(jiffies, timeout)) {
492 			dev_err(&spi->dev, "MCP251x didn't enter in config mode\n");
493 			return -EBUSY;
494 		}
495 	}
496 
497 	/* Disable and clear pending interrupts */
498 	mcp251x_write_2regs(spi, CANINTE, 0x00, 0x00);
499 	enable_irq(spi->irq);
500 
501 	return 0;
502 }
503 
504 static netdev_tx_t mcp251x_hard_start_xmit(struct sk_buff *skb,
505 					   struct net_device *net)
506 {
507 	struct mcp251x_priv *priv = netdev_priv(net);
508 	struct spi_device *spi = priv->spi;
509 
510 	if (priv->tx_skb || priv->tx_len) {
511 		dev_warn(&spi->dev, "hard_xmit called while tx busy\n");
512 		return NETDEV_TX_BUSY;
513 	}
514 
515 	if (can_dropped_invalid_skb(net, skb))
516 		return NETDEV_TX_OK;
517 
518 	netif_stop_queue(net);
519 	priv->tx_skb = skb;
520 	queue_work(priv->wq, &priv->tx_work);
521 
522 	return NETDEV_TX_OK;
523 }
524 
525 static int mcp251x_do_set_mode(struct net_device *net, enum can_mode mode)
526 {
527 	struct mcp251x_priv *priv = netdev_priv(net);
528 
529 	switch (mode) {
530 	case CAN_MODE_START:
531 		mcp251x_clean(net);
532 		/* We have to delay work since SPI I/O may sleep */
533 		priv->can.state = CAN_STATE_ERROR_ACTIVE;
534 		priv->restart_tx = 1;
535 		if (priv->can.restart_ms == 0)
536 			priv->after_suspend = AFTER_SUSPEND_RESTART;
537 		queue_work(priv->wq, &priv->restart_work);
538 		break;
539 	default:
540 		return -EOPNOTSUPP;
541 	}
542 
543 	return 0;
544 }
545 
546 static int mcp251x_set_normal_mode(struct spi_device *spi)
547 {
548 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
549 	unsigned long timeout;
550 
551 	/* Enable interrupts */
552 	mcp251x_write_reg(spi, CANINTE,
553 			  CANINTE_ERRIE | CANINTE_TX2IE | CANINTE_TX1IE |
554 			  CANINTE_TX0IE | CANINTE_RX1IE | CANINTE_RX0IE);
555 
556 	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
557 		/* Put device into loopback mode */
558 		mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LOOPBACK);
559 	} else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) {
560 		/* Put device into listen-only mode */
561 		mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LISTEN_ONLY);
562 	} else {
563 		/* Put device into normal mode */
564 		mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_NORMAL);
565 
566 		/* Wait for the device to enter normal mode */
567 		timeout = jiffies + HZ;
568 		while (mcp251x_read_reg(spi, CANSTAT) & CANCTRL_REQOP_MASK) {
569 			schedule();
570 			if (time_after(jiffies, timeout)) {
571 				dev_err(&spi->dev, "MCP251x didn't enter in normal mode\n");
572 				return -EBUSY;
573 			}
574 		}
575 	}
576 	priv->can.state = CAN_STATE_ERROR_ACTIVE;
577 	return 0;
578 }
579 
580 static int mcp251x_do_set_bittiming(struct net_device *net)
581 {
582 	struct mcp251x_priv *priv = netdev_priv(net);
583 	struct can_bittiming *bt = &priv->can.bittiming;
584 	struct spi_device *spi = priv->spi;
585 
586 	mcp251x_write_reg(spi, CNF1, ((bt->sjw - 1) << CNF1_SJW_SHIFT) |
587 			  (bt->brp - 1));
588 	mcp251x_write_reg(spi, CNF2, CNF2_BTLMODE |
589 			  (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES ?
590 			   CNF2_SAM : 0) |
591 			  ((bt->phase_seg1 - 1) << CNF2_PS1_SHIFT) |
592 			  (bt->prop_seg - 1));
593 	mcp251x_write_bits(spi, CNF3, CNF3_PHSEG2_MASK,
594 			   (bt->phase_seg2 - 1));
595 	dev_dbg(&spi->dev, "CNF: 0x%02x 0x%02x 0x%02x\n",
596 		mcp251x_read_reg(spi, CNF1),
597 		mcp251x_read_reg(spi, CNF2),
598 		mcp251x_read_reg(spi, CNF3));
599 
600 	return 0;
601 }
602 
603 static int mcp251x_setup(struct net_device *net, struct spi_device *spi)
604 {
605 	mcp251x_do_set_bittiming(net);
606 
607 	mcp251x_write_reg(spi, RXBCTRL(0),
608 			  RXBCTRL_BUKT | RXBCTRL_RXM0 | RXBCTRL_RXM1);
609 	mcp251x_write_reg(spi, RXBCTRL(1),
610 			  RXBCTRL_RXM0 | RXBCTRL_RXM1);
611 	return 0;
612 }
613 
614 static int mcp251x_hw_reset(struct spi_device *spi)
615 {
616 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
617 	unsigned long timeout;
618 	int ret;
619 
620 	/* Wait for oscillator startup timer after power up */
621 	mdelay(MCP251X_OST_DELAY_MS);
622 
623 	priv->spi_tx_buf[0] = INSTRUCTION_RESET;
624 	ret = mcp251x_spi_trans(spi, 1);
625 	if (ret)
626 		return ret;
627 
628 	/* Wait for oscillator startup timer after reset */
629 	mdelay(MCP251X_OST_DELAY_MS);
630 
631 	/* Wait for reset to finish */
632 	timeout = jiffies + HZ;
633 	while ((mcp251x_read_reg(spi, CANSTAT) & CANCTRL_REQOP_MASK) !=
634 	       CANCTRL_REQOP_CONF) {
635 		usleep_range(MCP251X_OST_DELAY_MS * 1000,
636 			     MCP251X_OST_DELAY_MS * 1000 * 2);
637 
638 		if (time_after(jiffies, timeout)) {
639 			dev_err(&spi->dev,
640 				"MCP251x didn't enter in conf mode after reset\n");
641 			return -EBUSY;
642 		}
643 	}
644 	return 0;
645 }
646 
647 static int mcp251x_hw_probe(struct spi_device *spi)
648 {
649 	u8 ctrl;
650 	int ret;
651 
652 	ret = mcp251x_hw_reset(spi);
653 	if (ret)
654 		return ret;
655 
656 	ctrl = mcp251x_read_reg(spi, CANCTRL);
657 
658 	dev_dbg(&spi->dev, "CANCTRL 0x%02x\n", ctrl);
659 
660 	/* Check for power up default value */
661 	if ((ctrl & 0x17) != 0x07)
662 		return -ENODEV;
663 
664 	return 0;
665 }
666 
667 static int mcp251x_power_enable(struct regulator *reg, int enable)
668 {
669 	if (IS_ERR_OR_NULL(reg))
670 		return 0;
671 
672 	if (enable)
673 		return regulator_enable(reg);
674 	else
675 		return regulator_disable(reg);
676 }
677 
678 static int mcp251x_stop(struct net_device *net)
679 {
680 	struct mcp251x_priv *priv = netdev_priv(net);
681 	struct spi_device *spi = priv->spi;
682 
683 	close_candev(net);
684 
685 	priv->force_quit = 1;
686 	free_irq(spi->irq, priv);
687 	destroy_workqueue(priv->wq);
688 	priv->wq = NULL;
689 
690 	mutex_lock(&priv->mcp_lock);
691 
692 	/* Disable and clear pending interrupts */
693 	mcp251x_write_2regs(spi, CANINTE, 0x00, 0x00);
694 
695 	mcp251x_write_reg(spi, TXBCTRL(0), 0);
696 	mcp251x_clean(net);
697 
698 	mcp251x_hw_sleep(spi);
699 
700 	mcp251x_power_enable(priv->transceiver, 0);
701 
702 	priv->can.state = CAN_STATE_STOPPED;
703 
704 	mutex_unlock(&priv->mcp_lock);
705 
706 	can_led_event(net, CAN_LED_EVENT_STOP);
707 
708 	return 0;
709 }
710 
711 static void mcp251x_error_skb(struct net_device *net, int can_id, int data1)
712 {
713 	struct sk_buff *skb;
714 	struct can_frame *frame;
715 
716 	skb = alloc_can_err_skb(net, &frame);
717 	if (skb) {
718 		frame->can_id |= can_id;
719 		frame->data[1] = data1;
720 		netif_rx_ni(skb);
721 	} else {
722 		netdev_err(net, "cannot allocate error skb\n");
723 	}
724 }
725 
726 static void mcp251x_tx_work_handler(struct work_struct *ws)
727 {
728 	struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv,
729 						 tx_work);
730 	struct spi_device *spi = priv->spi;
731 	struct net_device *net = priv->net;
732 	struct can_frame *frame;
733 
734 	mutex_lock(&priv->mcp_lock);
735 	if (priv->tx_skb) {
736 		if (priv->can.state == CAN_STATE_BUS_OFF) {
737 			mcp251x_clean(net);
738 		} else {
739 			frame = (struct can_frame *)priv->tx_skb->data;
740 
741 			if (frame->can_dlc > CAN_FRAME_MAX_DATA_LEN)
742 				frame->can_dlc = CAN_FRAME_MAX_DATA_LEN;
743 			mcp251x_hw_tx(spi, frame, 0);
744 			priv->tx_len = 1 + frame->can_dlc;
745 			can_put_echo_skb(priv->tx_skb, net, 0);
746 			priv->tx_skb = NULL;
747 		}
748 	}
749 	mutex_unlock(&priv->mcp_lock);
750 }
751 
752 static void mcp251x_restart_work_handler(struct work_struct *ws)
753 {
754 	struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv,
755 						 restart_work);
756 	struct spi_device *spi = priv->spi;
757 	struct net_device *net = priv->net;
758 
759 	mutex_lock(&priv->mcp_lock);
760 	if (priv->after_suspend) {
761 		if (priv->after_suspend & AFTER_SUSPEND_POWER) {
762 			mcp251x_hw_reset(spi);
763 			mcp251x_setup(net, spi);
764 		} else {
765 			mcp251x_hw_wake(spi);
766 		}
767 		priv->force_quit = 0;
768 		if (priv->after_suspend & AFTER_SUSPEND_RESTART) {
769 			mcp251x_set_normal_mode(spi);
770 		} else if (priv->after_suspend & AFTER_SUSPEND_UP) {
771 			netif_device_attach(net);
772 			mcp251x_clean(net);
773 			mcp251x_set_normal_mode(spi);
774 			netif_wake_queue(net);
775 		} else {
776 			mcp251x_hw_sleep(spi);
777 		}
778 		priv->after_suspend = 0;
779 	}
780 
781 	if (priv->restart_tx) {
782 		priv->restart_tx = 0;
783 		mcp251x_write_reg(spi, TXBCTRL(0), 0);
784 		mcp251x_clean(net);
785 		netif_wake_queue(net);
786 		mcp251x_error_skb(net, CAN_ERR_RESTARTED, 0);
787 	}
788 	mutex_unlock(&priv->mcp_lock);
789 }
790 
791 static irqreturn_t mcp251x_can_ist(int irq, void *dev_id)
792 {
793 	struct mcp251x_priv *priv = dev_id;
794 	struct spi_device *spi = priv->spi;
795 	struct net_device *net = priv->net;
796 
797 	mutex_lock(&priv->mcp_lock);
798 	while (!priv->force_quit) {
799 		enum can_state new_state;
800 		u8 intf, eflag;
801 		u8 clear_intf = 0;
802 		int can_id = 0, data1 = 0;
803 
804 		mcp251x_read_2regs(spi, CANINTF, &intf, &eflag);
805 
806 		/* mask out flags we don't care about */
807 		intf &= CANINTF_RX | CANINTF_TX | CANINTF_ERR;
808 
809 		/* receive buffer 0 */
810 		if (intf & CANINTF_RX0IF) {
811 			mcp251x_hw_rx(spi, 0);
812 			/* Free one buffer ASAP
813 			 * (The MCP2515/25625 does this automatically.)
814 			 */
815 			if (mcp251x_is_2510(spi))
816 				mcp251x_write_bits(spi, CANINTF,
817 						   CANINTF_RX0IF, 0x00);
818 		}
819 
820 		/* receive buffer 1 */
821 		if (intf & CANINTF_RX1IF) {
822 			mcp251x_hw_rx(spi, 1);
823 			/* The MCP2515/25625 does this automatically. */
824 			if (mcp251x_is_2510(spi))
825 				clear_intf |= CANINTF_RX1IF;
826 		}
827 
828 		/* any error or tx interrupt we need to clear? */
829 		if (intf & (CANINTF_ERR | CANINTF_TX))
830 			clear_intf |= intf & (CANINTF_ERR | CANINTF_TX);
831 		if (clear_intf)
832 			mcp251x_write_bits(spi, CANINTF, clear_intf, 0x00);
833 
834 		if (eflag & (EFLG_RX0OVR | EFLG_RX1OVR))
835 			mcp251x_write_bits(spi, EFLG, eflag, 0x00);
836 
837 		/* Update can state */
838 		if (eflag & EFLG_TXBO) {
839 			new_state = CAN_STATE_BUS_OFF;
840 			can_id |= CAN_ERR_BUSOFF;
841 		} else if (eflag & EFLG_TXEP) {
842 			new_state = CAN_STATE_ERROR_PASSIVE;
843 			can_id |= CAN_ERR_CRTL;
844 			data1 |= CAN_ERR_CRTL_TX_PASSIVE;
845 		} else if (eflag & EFLG_RXEP) {
846 			new_state = CAN_STATE_ERROR_PASSIVE;
847 			can_id |= CAN_ERR_CRTL;
848 			data1 |= CAN_ERR_CRTL_RX_PASSIVE;
849 		} else if (eflag & EFLG_TXWAR) {
850 			new_state = CAN_STATE_ERROR_WARNING;
851 			can_id |= CAN_ERR_CRTL;
852 			data1 |= CAN_ERR_CRTL_TX_WARNING;
853 		} else if (eflag & EFLG_RXWAR) {
854 			new_state = CAN_STATE_ERROR_WARNING;
855 			can_id |= CAN_ERR_CRTL;
856 			data1 |= CAN_ERR_CRTL_RX_WARNING;
857 		} else {
858 			new_state = CAN_STATE_ERROR_ACTIVE;
859 		}
860 
861 		/* Update can state statistics */
862 		switch (priv->can.state) {
863 		case CAN_STATE_ERROR_ACTIVE:
864 			if (new_state >= CAN_STATE_ERROR_WARNING &&
865 			    new_state <= CAN_STATE_BUS_OFF)
866 				priv->can.can_stats.error_warning++;
867 			/* fall through */
868 		case CAN_STATE_ERROR_WARNING:
869 			if (new_state >= CAN_STATE_ERROR_PASSIVE &&
870 			    new_state <= CAN_STATE_BUS_OFF)
871 				priv->can.can_stats.error_passive++;
872 			break;
873 		default:
874 			break;
875 		}
876 		priv->can.state = new_state;
877 
878 		if (intf & CANINTF_ERRIF) {
879 			/* Handle overflow counters */
880 			if (eflag & (EFLG_RX0OVR | EFLG_RX1OVR)) {
881 				if (eflag & EFLG_RX0OVR) {
882 					net->stats.rx_over_errors++;
883 					net->stats.rx_errors++;
884 				}
885 				if (eflag & EFLG_RX1OVR) {
886 					net->stats.rx_over_errors++;
887 					net->stats.rx_errors++;
888 				}
889 				can_id |= CAN_ERR_CRTL;
890 				data1 |= CAN_ERR_CRTL_RX_OVERFLOW;
891 			}
892 			mcp251x_error_skb(net, can_id, data1);
893 		}
894 
895 		if (priv->can.state == CAN_STATE_BUS_OFF) {
896 			if (priv->can.restart_ms == 0) {
897 				priv->force_quit = 1;
898 				priv->can.can_stats.bus_off++;
899 				can_bus_off(net);
900 				mcp251x_hw_sleep(spi);
901 				break;
902 			}
903 		}
904 
905 		if (intf == 0)
906 			break;
907 
908 		if (intf & CANINTF_TX) {
909 			net->stats.tx_packets++;
910 			net->stats.tx_bytes += priv->tx_len - 1;
911 			can_led_event(net, CAN_LED_EVENT_TX);
912 			if (priv->tx_len) {
913 				can_get_echo_skb(net, 0);
914 				priv->tx_len = 0;
915 			}
916 			netif_wake_queue(net);
917 		}
918 	}
919 	mutex_unlock(&priv->mcp_lock);
920 	return IRQ_HANDLED;
921 }
922 
923 static int mcp251x_open(struct net_device *net)
924 {
925 	struct mcp251x_priv *priv = netdev_priv(net);
926 	struct spi_device *spi = priv->spi;
927 	unsigned long flags = 0;
928 	int ret;
929 
930 	ret = open_candev(net);
931 	if (ret) {
932 		dev_err(&spi->dev, "unable to set initial baudrate!\n");
933 		return ret;
934 	}
935 
936 	mutex_lock(&priv->mcp_lock);
937 	mcp251x_power_enable(priv->transceiver, 1);
938 
939 	priv->force_quit = 0;
940 	priv->tx_skb = NULL;
941 	priv->tx_len = 0;
942 
943 	if (!dev_fwnode(&spi->dev))
944 		flags = IRQF_TRIGGER_FALLING;
945 
946 	ret = request_threaded_irq(spi->irq, NULL, mcp251x_can_ist,
947 				   flags | IRQF_ONESHOT, dev_name(&spi->dev),
948 				   priv);
949 	if (ret) {
950 		dev_err(&spi->dev, "failed to acquire irq %d\n", spi->irq);
951 		goto out_close;
952 	}
953 
954 	priv->wq = alloc_workqueue("mcp251x_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM,
955 				   0);
956 	if (!priv->wq) {
957 		ret = -ENOMEM;
958 		goto out_clean;
959 	}
960 	INIT_WORK(&priv->tx_work, mcp251x_tx_work_handler);
961 	INIT_WORK(&priv->restart_work, mcp251x_restart_work_handler);
962 
963 	ret = mcp251x_hw_wake(spi);
964 	if (ret)
965 		goto out_free_wq;
966 	ret = mcp251x_setup(net, spi);
967 	if (ret)
968 		goto out_free_wq;
969 	ret = mcp251x_set_normal_mode(spi);
970 	if (ret)
971 		goto out_free_wq;
972 
973 	can_led_event(net, CAN_LED_EVENT_OPEN);
974 
975 	netif_wake_queue(net);
976 	mutex_unlock(&priv->mcp_lock);
977 
978 	return 0;
979 
980 out_free_wq:
981 	destroy_workqueue(priv->wq);
982 out_clean:
983 	free_irq(spi->irq, priv);
984 	mcp251x_hw_sleep(spi);
985 out_close:
986 	mcp251x_power_enable(priv->transceiver, 0);
987 	close_candev(net);
988 	mutex_unlock(&priv->mcp_lock);
989 	return ret;
990 }
991 
992 static const struct net_device_ops mcp251x_netdev_ops = {
993 	.ndo_open = mcp251x_open,
994 	.ndo_stop = mcp251x_stop,
995 	.ndo_start_xmit = mcp251x_hard_start_xmit,
996 	.ndo_change_mtu = can_change_mtu,
997 };
998 
999 static const struct of_device_id mcp251x_of_match[] = {
1000 	{
1001 		.compatible	= "microchip,mcp2510",
1002 		.data		= (void *)CAN_MCP251X_MCP2510,
1003 	},
1004 	{
1005 		.compatible	= "microchip,mcp2515",
1006 		.data		= (void *)CAN_MCP251X_MCP2515,
1007 	},
1008 	{
1009 		.compatible	= "microchip,mcp25625",
1010 		.data		= (void *)CAN_MCP251X_MCP25625,
1011 	},
1012 	{ }
1013 };
1014 MODULE_DEVICE_TABLE(of, mcp251x_of_match);
1015 
1016 static const struct spi_device_id mcp251x_id_table[] = {
1017 	{
1018 		.name		= "mcp2510",
1019 		.driver_data	= (kernel_ulong_t)CAN_MCP251X_MCP2510,
1020 	},
1021 	{
1022 		.name		= "mcp2515",
1023 		.driver_data	= (kernel_ulong_t)CAN_MCP251X_MCP2515,
1024 	},
1025 	{
1026 		.name		= "mcp25625",
1027 		.driver_data	= (kernel_ulong_t)CAN_MCP251X_MCP25625,
1028 	},
1029 	{ }
1030 };
1031 MODULE_DEVICE_TABLE(spi, mcp251x_id_table);
1032 
1033 static int mcp251x_can_probe(struct spi_device *spi)
1034 {
1035 	const void *match = device_get_match_data(&spi->dev);
1036 	struct net_device *net;
1037 	struct mcp251x_priv *priv;
1038 	struct clk *clk;
1039 	u32 freq;
1040 	int ret;
1041 
1042 	clk = devm_clk_get_optional(&spi->dev, NULL);
1043 	if (IS_ERR(clk))
1044 		return PTR_ERR(clk);
1045 
1046 	freq = clk_get_rate(clk);
1047 	if (freq == 0)
1048 		device_property_read_u32(&spi->dev, "clock-frequency", &freq);
1049 
1050 	/* Sanity check */
1051 	if (freq < 1000000 || freq > 25000000)
1052 		return -ERANGE;
1053 
1054 	/* Allocate can/net device */
1055 	net = alloc_candev(sizeof(struct mcp251x_priv), TX_ECHO_SKB_MAX);
1056 	if (!net)
1057 		return -ENOMEM;
1058 
1059 	ret = clk_prepare_enable(clk);
1060 	if (ret)
1061 		goto out_free;
1062 
1063 	net->netdev_ops = &mcp251x_netdev_ops;
1064 	net->flags |= IFF_ECHO;
1065 
1066 	priv = netdev_priv(net);
1067 	priv->can.bittiming_const = &mcp251x_bittiming_const;
1068 	priv->can.do_set_mode = mcp251x_do_set_mode;
1069 	priv->can.clock.freq = freq / 2;
1070 	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
1071 		CAN_CTRLMODE_LOOPBACK | CAN_CTRLMODE_LISTENONLY;
1072 	if (match)
1073 		priv->model = (enum mcp251x_model)match;
1074 	else
1075 		priv->model = spi_get_device_id(spi)->driver_data;
1076 	priv->net = net;
1077 	priv->clk = clk;
1078 
1079 	spi_set_drvdata(spi, priv);
1080 
1081 	/* Configure the SPI bus */
1082 	spi->bits_per_word = 8;
1083 	if (mcp251x_is_2510(spi))
1084 		spi->max_speed_hz = spi->max_speed_hz ? : 5 * 1000 * 1000;
1085 	else
1086 		spi->max_speed_hz = spi->max_speed_hz ? : 10 * 1000 * 1000;
1087 	ret = spi_setup(spi);
1088 	if (ret)
1089 		goto out_clk;
1090 
1091 	priv->power = devm_regulator_get_optional(&spi->dev, "vdd");
1092 	priv->transceiver = devm_regulator_get_optional(&spi->dev, "xceiver");
1093 	if ((PTR_ERR(priv->power) == -EPROBE_DEFER) ||
1094 	    (PTR_ERR(priv->transceiver) == -EPROBE_DEFER)) {
1095 		ret = -EPROBE_DEFER;
1096 		goto out_clk;
1097 	}
1098 
1099 	ret = mcp251x_power_enable(priv->power, 1);
1100 	if (ret)
1101 		goto out_clk;
1102 
1103 	priv->spi = spi;
1104 	mutex_init(&priv->mcp_lock);
1105 
1106 	priv->spi_tx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,
1107 					GFP_KERNEL);
1108 	if (!priv->spi_tx_buf) {
1109 		ret = -ENOMEM;
1110 		goto error_probe;
1111 	}
1112 
1113 	priv->spi_rx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,
1114 					GFP_KERNEL);
1115 	if (!priv->spi_rx_buf) {
1116 		ret = -ENOMEM;
1117 		goto error_probe;
1118 	}
1119 
1120 	SET_NETDEV_DEV(net, &spi->dev);
1121 
1122 	/* Here is OK to not lock the MCP, no one knows about it yet */
1123 	ret = mcp251x_hw_probe(spi);
1124 	if (ret) {
1125 		if (ret == -ENODEV)
1126 			dev_err(&spi->dev, "Cannot initialize MCP%x. Wrong wiring?\n",
1127 				priv->model);
1128 		goto error_probe;
1129 	}
1130 
1131 	mcp251x_hw_sleep(spi);
1132 
1133 	ret = register_candev(net);
1134 	if (ret)
1135 		goto error_probe;
1136 
1137 	devm_can_led_init(net);
1138 
1139 	netdev_info(net, "MCP%x successfully initialized.\n", priv->model);
1140 	return 0;
1141 
1142 error_probe:
1143 	mcp251x_power_enable(priv->power, 0);
1144 
1145 out_clk:
1146 	clk_disable_unprepare(clk);
1147 
1148 out_free:
1149 	free_candev(net);
1150 
1151 	dev_err(&spi->dev, "Probe failed, err=%d\n", -ret);
1152 	return ret;
1153 }
1154 
1155 static int mcp251x_can_remove(struct spi_device *spi)
1156 {
1157 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
1158 	struct net_device *net = priv->net;
1159 
1160 	unregister_candev(net);
1161 
1162 	mcp251x_power_enable(priv->power, 0);
1163 
1164 	clk_disable_unprepare(priv->clk);
1165 
1166 	free_candev(net);
1167 
1168 	return 0;
1169 }
1170 
1171 static int __maybe_unused mcp251x_can_suspend(struct device *dev)
1172 {
1173 	struct spi_device *spi = to_spi_device(dev);
1174 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
1175 	struct net_device *net = priv->net;
1176 
1177 	priv->force_quit = 1;
1178 	disable_irq(spi->irq);
1179 	/* Note: at this point neither IST nor workqueues are running.
1180 	 * open/stop cannot be called anyway so locking is not needed
1181 	 */
1182 	if (netif_running(net)) {
1183 		netif_device_detach(net);
1184 
1185 		mcp251x_hw_sleep(spi);
1186 		mcp251x_power_enable(priv->transceiver, 0);
1187 		priv->after_suspend = AFTER_SUSPEND_UP;
1188 	} else {
1189 		priv->after_suspend = AFTER_SUSPEND_DOWN;
1190 	}
1191 
1192 	mcp251x_power_enable(priv->power, 0);
1193 	priv->after_suspend |= AFTER_SUSPEND_POWER;
1194 
1195 	return 0;
1196 }
1197 
1198 static int __maybe_unused mcp251x_can_resume(struct device *dev)
1199 {
1200 	struct spi_device *spi = to_spi_device(dev);
1201 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
1202 
1203 	if (priv->after_suspend & AFTER_SUSPEND_POWER)
1204 		mcp251x_power_enable(priv->power, 1);
1205 	if (priv->after_suspend & AFTER_SUSPEND_UP)
1206 		mcp251x_power_enable(priv->transceiver, 1);
1207 
1208 	if (priv->after_suspend & (AFTER_SUSPEND_POWER | AFTER_SUSPEND_UP))
1209 		queue_work(priv->wq, &priv->restart_work);
1210 	else
1211 		priv->after_suspend = 0;
1212 
1213 	priv->force_quit = 0;
1214 	enable_irq(spi->irq);
1215 	return 0;
1216 }
1217 
1218 static SIMPLE_DEV_PM_OPS(mcp251x_can_pm_ops, mcp251x_can_suspend,
1219 	mcp251x_can_resume);
1220 
1221 static struct spi_driver mcp251x_can_driver = {
1222 	.driver = {
1223 		.name = DEVICE_NAME,
1224 		.of_match_table = mcp251x_of_match,
1225 		.pm = &mcp251x_can_pm_ops,
1226 	},
1227 	.id_table = mcp251x_id_table,
1228 	.probe = mcp251x_can_probe,
1229 	.remove = mcp251x_can_remove,
1230 };
1231 module_spi_driver(mcp251x_can_driver);
1232 
1233 MODULE_AUTHOR("Chris Elston <celston@katalix.com>, "
1234 	      "Christian Pellegrin <chripell@evolware.org>");
1235 MODULE_DESCRIPTION("Microchip 251x/25625 CAN driver");
1236 MODULE_LICENSE("GPL v2");
1237