xref: /openbmc/linux/drivers/net/can/spi/mcp251x.c (revision 5e29a910)
1 /*
2  * CAN bus driver for Microchip 251x 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  * This program is free software; you can redistribute it and/or modify
22  * it under the terms of the version 2 of the GNU General Public License
23  * as published by the Free Software Foundation
24  *
25  * This program is distributed in the hope that it will be useful,
26  * but WITHOUT ANY WARRANTY; without even the implied warranty of
27  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
28  * GNU General Public License for more details.
29  *
30  * You should have received a copy of the GNU General Public License
31  * along with this program; if not, see <http://www.gnu.org/licenses/>.
32  *
33  *
34  *
35  * Your platform definition file should specify something like:
36  *
37  * static struct mcp251x_platform_data mcp251x_info = {
38  *         .oscillator_frequency = 8000000,
39  * };
40  *
41  * static struct spi_board_info spi_board_info[] = {
42  *         {
43  *                 .modalias = "mcp2510",
44  *			// or "mcp2515" depending on your controller
45  *                 .platform_data = &mcp251x_info,
46  *                 .irq = IRQ_EINT13,
47  *                 .max_speed_hz = 2*1000*1000,
48  *                 .chip_select = 2,
49  *         },
50  * };
51  *
52  * Please see mcp251x.h for a description of the fields in
53  * struct mcp251x_platform_data.
54  *
55  */
56 
57 #include <linux/can/core.h>
58 #include <linux/can/dev.h>
59 #include <linux/can/led.h>
60 #include <linux/can/platform/mcp251x.h>
61 #include <linux/clk.h>
62 #include <linux/completion.h>
63 #include <linux/delay.h>
64 #include <linux/device.h>
65 #include <linux/dma-mapping.h>
66 #include <linux/freezer.h>
67 #include <linux/interrupt.h>
68 #include <linux/io.h>
69 #include <linux/kernel.h>
70 #include <linux/module.h>
71 #include <linux/netdevice.h>
72 #include <linux/of.h>
73 #include <linux/of_device.h>
74 #include <linux/platform_device.h>
75 #include <linux/slab.h>
76 #include <linux/spi/spi.h>
77 #include <linux/uaccess.h>
78 #include <linux/regulator/consumer.h>
79 
80 /* SPI interface instruction set */
81 #define INSTRUCTION_WRITE	0x02
82 #define INSTRUCTION_READ	0x03
83 #define INSTRUCTION_BIT_MODIFY	0x05
84 #define INSTRUCTION_LOAD_TXB(n)	(0x40 + 2 * (n))
85 #define INSTRUCTION_READ_RXB(n)	(((n) == 0) ? 0x90 : 0x94)
86 #define INSTRUCTION_RESET	0xC0
87 #define RTS_TXB0		0x01
88 #define RTS_TXB1		0x02
89 #define RTS_TXB2		0x04
90 #define INSTRUCTION_RTS(n)	(0x80 | ((n) & 0x07))
91 
92 
93 /* MPC251x registers */
94 #define CANSTAT	      0x0e
95 #define CANCTRL	      0x0f
96 #  define CANCTRL_REQOP_MASK	    0xe0
97 #  define CANCTRL_REQOP_CONF	    0x80
98 #  define CANCTRL_REQOP_LISTEN_ONLY 0x60
99 #  define CANCTRL_REQOP_LOOPBACK    0x40
100 #  define CANCTRL_REQOP_SLEEP	    0x20
101 #  define CANCTRL_REQOP_NORMAL	    0x00
102 #  define CANCTRL_OSM		    0x08
103 #  define CANCTRL_ABAT		    0x10
104 #define TEC	      0x1c
105 #define REC	      0x1d
106 #define CNF1	      0x2a
107 #  define CNF1_SJW_SHIFT   6
108 #define CNF2	      0x29
109 #  define CNF2_BTLMODE	   0x80
110 #  define CNF2_SAM         0x40
111 #  define CNF2_PS1_SHIFT   3
112 #define CNF3	      0x28
113 #  define CNF3_SOF	   0x08
114 #  define CNF3_WAKFIL	   0x04
115 #  define CNF3_PHSEG2_MASK 0x07
116 #define CANINTE	      0x2b
117 #  define CANINTE_MERRE 0x80
118 #  define CANINTE_WAKIE 0x40
119 #  define CANINTE_ERRIE 0x20
120 #  define CANINTE_TX2IE 0x10
121 #  define CANINTE_TX1IE 0x08
122 #  define CANINTE_TX0IE 0x04
123 #  define CANINTE_RX1IE 0x02
124 #  define CANINTE_RX0IE 0x01
125 #define CANINTF	      0x2c
126 #  define CANINTF_MERRF 0x80
127 #  define CANINTF_WAKIF 0x40
128 #  define CANINTF_ERRIF 0x20
129 #  define CANINTF_TX2IF 0x10
130 #  define CANINTF_TX1IF 0x08
131 #  define CANINTF_TX0IF 0x04
132 #  define CANINTF_RX1IF 0x02
133 #  define CANINTF_RX0IF 0x01
134 #  define CANINTF_RX (CANINTF_RX0IF | CANINTF_RX1IF)
135 #  define CANINTF_TX (CANINTF_TX2IF | CANINTF_TX1IF | CANINTF_TX0IF)
136 #  define CANINTF_ERR (CANINTF_ERRIF)
137 #define EFLG	      0x2d
138 #  define EFLG_EWARN	0x01
139 #  define EFLG_RXWAR	0x02
140 #  define EFLG_TXWAR	0x04
141 #  define EFLG_RXEP	0x08
142 #  define EFLG_TXEP	0x10
143 #  define EFLG_TXBO	0x20
144 #  define EFLG_RX0OVR	0x40
145 #  define EFLG_RX1OVR	0x80
146 #define TXBCTRL(n)  (((n) * 0x10) + 0x30 + TXBCTRL_OFF)
147 #  define TXBCTRL_ABTF	0x40
148 #  define TXBCTRL_MLOA	0x20
149 #  define TXBCTRL_TXERR 0x10
150 #  define TXBCTRL_TXREQ 0x08
151 #define TXBSIDH(n)  (((n) * 0x10) + 0x30 + TXBSIDH_OFF)
152 #  define SIDH_SHIFT    3
153 #define TXBSIDL(n)  (((n) * 0x10) + 0x30 + TXBSIDL_OFF)
154 #  define SIDL_SID_MASK    7
155 #  define SIDL_SID_SHIFT   5
156 #  define SIDL_EXIDE_SHIFT 3
157 #  define SIDL_EID_SHIFT   16
158 #  define SIDL_EID_MASK    3
159 #define TXBEID8(n)  (((n) * 0x10) + 0x30 + TXBEID8_OFF)
160 #define TXBEID0(n)  (((n) * 0x10) + 0x30 + TXBEID0_OFF)
161 #define TXBDLC(n)   (((n) * 0x10) + 0x30 + TXBDLC_OFF)
162 #  define DLC_RTR_SHIFT    6
163 #define TXBCTRL_OFF 0
164 #define TXBSIDH_OFF 1
165 #define TXBSIDL_OFF 2
166 #define TXBEID8_OFF 3
167 #define TXBEID0_OFF 4
168 #define TXBDLC_OFF  5
169 #define TXBDAT_OFF  6
170 #define RXBCTRL(n)  (((n) * 0x10) + 0x60 + RXBCTRL_OFF)
171 #  define RXBCTRL_BUKT	0x04
172 #  define RXBCTRL_RXM0	0x20
173 #  define RXBCTRL_RXM1	0x40
174 #define RXBSIDH(n)  (((n) * 0x10) + 0x60 + RXBSIDH_OFF)
175 #  define RXBSIDH_SHIFT 3
176 #define RXBSIDL(n)  (((n) * 0x10) + 0x60 + RXBSIDL_OFF)
177 #  define RXBSIDL_IDE   0x08
178 #  define RXBSIDL_SRR   0x10
179 #  define RXBSIDL_EID   3
180 #  define RXBSIDL_SHIFT 5
181 #define RXBEID8(n)  (((n) * 0x10) + 0x60 + RXBEID8_OFF)
182 #define RXBEID0(n)  (((n) * 0x10) + 0x60 + RXBEID0_OFF)
183 #define RXBDLC(n)   (((n) * 0x10) + 0x60 + RXBDLC_OFF)
184 #  define RXBDLC_LEN_MASK  0x0f
185 #  define RXBDLC_RTR       0x40
186 #define RXBCTRL_OFF 0
187 #define RXBSIDH_OFF 1
188 #define RXBSIDL_OFF 2
189 #define RXBEID8_OFF 3
190 #define RXBEID0_OFF 4
191 #define RXBDLC_OFF  5
192 #define RXBDAT_OFF  6
193 #define RXFSIDH(n) ((n) * 4)
194 #define RXFSIDL(n) ((n) * 4 + 1)
195 #define RXFEID8(n) ((n) * 4 + 2)
196 #define RXFEID0(n) ((n) * 4 + 3)
197 #define RXMSIDH(n) ((n) * 4 + 0x20)
198 #define RXMSIDL(n) ((n) * 4 + 0x21)
199 #define RXMEID8(n) ((n) * 4 + 0x22)
200 #define RXMEID0(n) ((n) * 4 + 0x23)
201 
202 #define GET_BYTE(val, byte)			\
203 	(((val) >> ((byte) * 8)) & 0xff)
204 #define SET_BYTE(val, byte)			\
205 	(((val) & 0xff) << ((byte) * 8))
206 
207 /*
208  * Buffer size required for the largest SPI transfer (i.e., reading a
209  * frame)
210  */
211 #define CAN_FRAME_MAX_DATA_LEN	8
212 #define SPI_TRANSFER_BUF_LEN	(6 + CAN_FRAME_MAX_DATA_LEN)
213 #define CAN_FRAME_MAX_BITS	128
214 
215 #define TX_ECHO_SKB_MAX	1
216 
217 #define MCP251X_OST_DELAY_MS	(5)
218 
219 #define DEVICE_NAME "mcp251x"
220 
221 static int mcp251x_enable_dma; /* Enable SPI DMA. Default: 0 (Off) */
222 module_param(mcp251x_enable_dma, int, S_IRUGO);
223 MODULE_PARM_DESC(mcp251x_enable_dma, "Enable SPI DMA. Default: 0 (Off)");
224 
225 static const struct can_bittiming_const mcp251x_bittiming_const = {
226 	.name = DEVICE_NAME,
227 	.tseg1_min = 3,
228 	.tseg1_max = 16,
229 	.tseg2_min = 2,
230 	.tseg2_max = 8,
231 	.sjw_max = 4,
232 	.brp_min = 1,
233 	.brp_max = 64,
234 	.brp_inc = 1,
235 };
236 
237 enum mcp251x_model {
238 	CAN_MCP251X_MCP2510	= 0x2510,
239 	CAN_MCP251X_MCP2515	= 0x2515,
240 };
241 
242 struct mcp251x_priv {
243 	struct can_priv	   can;
244 	struct net_device *net;
245 	struct spi_device *spi;
246 	enum mcp251x_model model;
247 
248 	struct mutex mcp_lock; /* SPI device lock */
249 
250 	u8 *spi_tx_buf;
251 	u8 *spi_rx_buf;
252 	dma_addr_t spi_tx_dma;
253 	dma_addr_t spi_rx_dma;
254 
255 	struct sk_buff *tx_skb;
256 	int tx_len;
257 
258 	struct workqueue_struct *wq;
259 	struct work_struct tx_work;
260 	struct work_struct restart_work;
261 
262 	int force_quit;
263 	int after_suspend;
264 #define AFTER_SUSPEND_UP 1
265 #define AFTER_SUSPEND_DOWN 2
266 #define AFTER_SUSPEND_POWER 4
267 #define AFTER_SUSPEND_RESTART 8
268 	int restart_tx;
269 	struct regulator *power;
270 	struct regulator *transceiver;
271 	struct clk *clk;
272 };
273 
274 #define MCP251X_IS(_model) \
275 static inline int mcp251x_is_##_model(struct spi_device *spi) \
276 { \
277 	struct mcp251x_priv *priv = spi_get_drvdata(spi); \
278 	return priv->model == CAN_MCP251X_MCP##_model; \
279 }
280 
281 MCP251X_IS(2510);
282 MCP251X_IS(2515);
283 
284 static void mcp251x_clean(struct net_device *net)
285 {
286 	struct mcp251x_priv *priv = netdev_priv(net);
287 
288 	if (priv->tx_skb || priv->tx_len)
289 		net->stats.tx_errors++;
290 	if (priv->tx_skb)
291 		dev_kfree_skb(priv->tx_skb);
292 	if (priv->tx_len)
293 		can_free_echo_skb(priv->net, 0);
294 	priv->tx_skb = NULL;
295 	priv->tx_len = 0;
296 }
297 
298 /*
299  * Note about handling of error return of mcp251x_spi_trans: accessing
300  * registers via SPI is not really different conceptually than using
301  * normal I/O assembler instructions, although it's much more
302  * complicated from a practical POV. So it's not advisable to always
303  * check the return value of this function. Imagine that every
304  * read{b,l}, write{b,l} and friends would be bracketed in "if ( < 0)
305  * error();", it would be a great mess (well there are some situation
306  * when exception handling C++ like could be useful after all). So we
307  * just check that transfers are OK at the beginning of our
308  * conversation with the chip and to avoid doing really nasty things
309  * (like injecting bogus packets in the network stack).
310  */
311 static int mcp251x_spi_trans(struct spi_device *spi, int len)
312 {
313 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
314 	struct spi_transfer t = {
315 		.tx_buf = priv->spi_tx_buf,
316 		.rx_buf = priv->spi_rx_buf,
317 		.len = len,
318 		.cs_change = 0,
319 	};
320 	struct spi_message m;
321 	int ret;
322 
323 	spi_message_init(&m);
324 
325 	if (mcp251x_enable_dma) {
326 		t.tx_dma = priv->spi_tx_dma;
327 		t.rx_dma = priv->spi_rx_dma;
328 		m.is_dma_mapped = 1;
329 	}
330 
331 	spi_message_add_tail(&t, &m);
332 
333 	ret = spi_sync(spi, &m);
334 	if (ret)
335 		dev_err(&spi->dev, "spi transfer failed: ret = %d\n", ret);
336 	return ret;
337 }
338 
339 static u8 mcp251x_read_reg(struct spi_device *spi, uint8_t reg)
340 {
341 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
342 	u8 val = 0;
343 
344 	priv->spi_tx_buf[0] = INSTRUCTION_READ;
345 	priv->spi_tx_buf[1] = reg;
346 
347 	mcp251x_spi_trans(spi, 3);
348 	val = priv->spi_rx_buf[2];
349 
350 	return val;
351 }
352 
353 static void mcp251x_read_2regs(struct spi_device *spi, uint8_t reg,
354 		uint8_t *v1, uint8_t *v2)
355 {
356 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
357 
358 	priv->spi_tx_buf[0] = INSTRUCTION_READ;
359 	priv->spi_tx_buf[1] = reg;
360 
361 	mcp251x_spi_trans(spi, 4);
362 
363 	*v1 = priv->spi_rx_buf[2];
364 	*v2 = priv->spi_rx_buf[3];
365 }
366 
367 static void mcp251x_write_reg(struct spi_device *spi, u8 reg, uint8_t val)
368 {
369 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
370 
371 	priv->spi_tx_buf[0] = INSTRUCTION_WRITE;
372 	priv->spi_tx_buf[1] = reg;
373 	priv->spi_tx_buf[2] = val;
374 
375 	mcp251x_spi_trans(spi, 3);
376 }
377 
378 static void mcp251x_write_bits(struct spi_device *spi, u8 reg,
379 			       u8 mask, uint8_t val)
380 {
381 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
382 
383 	priv->spi_tx_buf[0] = INSTRUCTION_BIT_MODIFY;
384 	priv->spi_tx_buf[1] = reg;
385 	priv->spi_tx_buf[2] = mask;
386 	priv->spi_tx_buf[3] = val;
387 
388 	mcp251x_spi_trans(spi, 4);
389 }
390 
391 static void mcp251x_hw_tx_frame(struct spi_device *spi, u8 *buf,
392 				int len, int tx_buf_idx)
393 {
394 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
395 
396 	if (mcp251x_is_2510(spi)) {
397 		int i;
398 
399 		for (i = 1; i < TXBDAT_OFF + len; i++)
400 			mcp251x_write_reg(spi, TXBCTRL(tx_buf_idx) + i,
401 					  buf[i]);
402 	} else {
403 		memcpy(priv->spi_tx_buf, buf, TXBDAT_OFF + len);
404 		mcp251x_spi_trans(spi, TXBDAT_OFF + len);
405 	}
406 }
407 
408 static void mcp251x_hw_tx(struct spi_device *spi, struct can_frame *frame,
409 			  int tx_buf_idx)
410 {
411 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
412 	u32 sid, eid, exide, rtr;
413 	u8 buf[SPI_TRANSFER_BUF_LEN];
414 
415 	exide = (frame->can_id & CAN_EFF_FLAG) ? 1 : 0; /* Extended ID Enable */
416 	if (exide)
417 		sid = (frame->can_id & CAN_EFF_MASK) >> 18;
418 	else
419 		sid = frame->can_id & CAN_SFF_MASK; /* Standard ID */
420 	eid = frame->can_id & CAN_EFF_MASK; /* Extended ID */
421 	rtr = (frame->can_id & CAN_RTR_FLAG) ? 1 : 0; /* Remote transmission */
422 
423 	buf[TXBCTRL_OFF] = INSTRUCTION_LOAD_TXB(tx_buf_idx);
424 	buf[TXBSIDH_OFF] = sid >> SIDH_SHIFT;
425 	buf[TXBSIDL_OFF] = ((sid & SIDL_SID_MASK) << SIDL_SID_SHIFT) |
426 		(exide << SIDL_EXIDE_SHIFT) |
427 		((eid >> SIDL_EID_SHIFT) & SIDL_EID_MASK);
428 	buf[TXBEID8_OFF] = GET_BYTE(eid, 1);
429 	buf[TXBEID0_OFF] = GET_BYTE(eid, 0);
430 	buf[TXBDLC_OFF] = (rtr << DLC_RTR_SHIFT) | frame->can_dlc;
431 	memcpy(buf + TXBDAT_OFF, frame->data, frame->can_dlc);
432 	mcp251x_hw_tx_frame(spi, buf, frame->can_dlc, tx_buf_idx);
433 
434 	/* use INSTRUCTION_RTS, to avoid "repeated frame problem" */
435 	priv->spi_tx_buf[0] = INSTRUCTION_RTS(1 << tx_buf_idx);
436 	mcp251x_spi_trans(priv->spi, 1);
437 }
438 
439 static void mcp251x_hw_rx_frame(struct spi_device *spi, u8 *buf,
440 				int buf_idx)
441 {
442 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
443 
444 	if (mcp251x_is_2510(spi)) {
445 		int i, len;
446 
447 		for (i = 1; i < RXBDAT_OFF; i++)
448 			buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i);
449 
450 		len = get_can_dlc(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK);
451 		for (; i < (RXBDAT_OFF + len); i++)
452 			buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i);
453 	} else {
454 		priv->spi_tx_buf[RXBCTRL_OFF] = INSTRUCTION_READ_RXB(buf_idx);
455 		mcp251x_spi_trans(spi, SPI_TRANSFER_BUF_LEN);
456 		memcpy(buf, priv->spi_rx_buf, SPI_TRANSFER_BUF_LEN);
457 	}
458 }
459 
460 static void mcp251x_hw_rx(struct spi_device *spi, int buf_idx)
461 {
462 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
463 	struct sk_buff *skb;
464 	struct can_frame *frame;
465 	u8 buf[SPI_TRANSFER_BUF_LEN];
466 
467 	skb = alloc_can_skb(priv->net, &frame);
468 	if (!skb) {
469 		dev_err(&spi->dev, "cannot allocate RX skb\n");
470 		priv->net->stats.rx_dropped++;
471 		return;
472 	}
473 
474 	mcp251x_hw_rx_frame(spi, buf, buf_idx);
475 	if (buf[RXBSIDL_OFF] & RXBSIDL_IDE) {
476 		/* Extended ID format */
477 		frame->can_id = CAN_EFF_FLAG;
478 		frame->can_id |=
479 			/* Extended ID part */
480 			SET_BYTE(buf[RXBSIDL_OFF] & RXBSIDL_EID, 2) |
481 			SET_BYTE(buf[RXBEID8_OFF], 1) |
482 			SET_BYTE(buf[RXBEID0_OFF], 0) |
483 			/* Standard ID part */
484 			(((buf[RXBSIDH_OFF] << RXBSIDH_SHIFT) |
485 			  (buf[RXBSIDL_OFF] >> RXBSIDL_SHIFT)) << 18);
486 		/* Remote transmission request */
487 		if (buf[RXBDLC_OFF] & RXBDLC_RTR)
488 			frame->can_id |= CAN_RTR_FLAG;
489 	} else {
490 		/* Standard ID format */
491 		frame->can_id =
492 			(buf[RXBSIDH_OFF] << RXBSIDH_SHIFT) |
493 			(buf[RXBSIDL_OFF] >> RXBSIDL_SHIFT);
494 		if (buf[RXBSIDL_OFF] & RXBSIDL_SRR)
495 			frame->can_id |= CAN_RTR_FLAG;
496 	}
497 	/* Data length */
498 	frame->can_dlc = get_can_dlc(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK);
499 	memcpy(frame->data, buf + RXBDAT_OFF, frame->can_dlc);
500 
501 	priv->net->stats.rx_packets++;
502 	priv->net->stats.rx_bytes += frame->can_dlc;
503 
504 	can_led_event(priv->net, CAN_LED_EVENT_RX);
505 
506 	netif_rx_ni(skb);
507 }
508 
509 static void mcp251x_hw_sleep(struct spi_device *spi)
510 {
511 	mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_SLEEP);
512 }
513 
514 static netdev_tx_t mcp251x_hard_start_xmit(struct sk_buff *skb,
515 					   struct net_device *net)
516 {
517 	struct mcp251x_priv *priv = netdev_priv(net);
518 	struct spi_device *spi = priv->spi;
519 
520 	if (priv->tx_skb || priv->tx_len) {
521 		dev_warn(&spi->dev, "hard_xmit called while tx busy\n");
522 		return NETDEV_TX_BUSY;
523 	}
524 
525 	if (can_dropped_invalid_skb(net, skb))
526 		return NETDEV_TX_OK;
527 
528 	netif_stop_queue(net);
529 	priv->tx_skb = skb;
530 	queue_work(priv->wq, &priv->tx_work);
531 
532 	return NETDEV_TX_OK;
533 }
534 
535 static int mcp251x_do_set_mode(struct net_device *net, enum can_mode mode)
536 {
537 	struct mcp251x_priv *priv = netdev_priv(net);
538 
539 	switch (mode) {
540 	case CAN_MODE_START:
541 		mcp251x_clean(net);
542 		/* We have to delay work since SPI I/O may sleep */
543 		priv->can.state = CAN_STATE_ERROR_ACTIVE;
544 		priv->restart_tx = 1;
545 		if (priv->can.restart_ms == 0)
546 			priv->after_suspend = AFTER_SUSPEND_RESTART;
547 		queue_work(priv->wq, &priv->restart_work);
548 		break;
549 	default:
550 		return -EOPNOTSUPP;
551 	}
552 
553 	return 0;
554 }
555 
556 static int mcp251x_set_normal_mode(struct spi_device *spi)
557 {
558 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
559 	unsigned long timeout;
560 
561 	/* Enable interrupts */
562 	mcp251x_write_reg(spi, CANINTE,
563 			  CANINTE_ERRIE | CANINTE_TX2IE | CANINTE_TX1IE |
564 			  CANINTE_TX0IE | CANINTE_RX1IE | CANINTE_RX0IE);
565 
566 	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
567 		/* Put device into loopback mode */
568 		mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LOOPBACK);
569 	} else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) {
570 		/* Put device into listen-only mode */
571 		mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LISTEN_ONLY);
572 	} else {
573 		/* Put device into normal mode */
574 		mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_NORMAL);
575 
576 		/* Wait for the device to enter normal mode */
577 		timeout = jiffies + HZ;
578 		while (mcp251x_read_reg(spi, CANSTAT) & CANCTRL_REQOP_MASK) {
579 			schedule();
580 			if (time_after(jiffies, timeout)) {
581 				dev_err(&spi->dev, "MCP251x didn't"
582 					" enter in normal mode\n");
583 				return -EBUSY;
584 			}
585 		}
586 	}
587 	priv->can.state = CAN_STATE_ERROR_ACTIVE;
588 	return 0;
589 }
590 
591 static int mcp251x_do_set_bittiming(struct net_device *net)
592 {
593 	struct mcp251x_priv *priv = netdev_priv(net);
594 	struct can_bittiming *bt = &priv->can.bittiming;
595 	struct spi_device *spi = priv->spi;
596 
597 	mcp251x_write_reg(spi, CNF1, ((bt->sjw - 1) << CNF1_SJW_SHIFT) |
598 			  (bt->brp - 1));
599 	mcp251x_write_reg(spi, CNF2, CNF2_BTLMODE |
600 			  (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES ?
601 			   CNF2_SAM : 0) |
602 			  ((bt->phase_seg1 - 1) << CNF2_PS1_SHIFT) |
603 			  (bt->prop_seg - 1));
604 	mcp251x_write_bits(spi, CNF3, CNF3_PHSEG2_MASK,
605 			   (bt->phase_seg2 - 1));
606 	dev_dbg(&spi->dev, "CNF: 0x%02x 0x%02x 0x%02x\n",
607 		mcp251x_read_reg(spi, CNF1),
608 		mcp251x_read_reg(spi, CNF2),
609 		mcp251x_read_reg(spi, CNF3));
610 
611 	return 0;
612 }
613 
614 static int mcp251x_setup(struct net_device *net, struct mcp251x_priv *priv,
615 			 struct spi_device *spi)
616 {
617 	mcp251x_do_set_bittiming(net);
618 
619 	mcp251x_write_reg(spi, RXBCTRL(0),
620 			  RXBCTRL_BUKT | RXBCTRL_RXM0 | RXBCTRL_RXM1);
621 	mcp251x_write_reg(spi, RXBCTRL(1),
622 			  RXBCTRL_RXM0 | RXBCTRL_RXM1);
623 	return 0;
624 }
625 
626 static int mcp251x_hw_reset(struct spi_device *spi)
627 {
628 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
629 	u8 reg;
630 	int ret;
631 
632 	/* Wait for oscillator startup timer after power up */
633 	mdelay(MCP251X_OST_DELAY_MS);
634 
635 	priv->spi_tx_buf[0] = INSTRUCTION_RESET;
636 	ret = mcp251x_spi_trans(spi, 1);
637 	if (ret)
638 		return ret;
639 
640 	/* Wait for oscillator startup timer after reset */
641 	mdelay(MCP251X_OST_DELAY_MS);
642 
643 	reg = mcp251x_read_reg(spi, CANSTAT);
644 	if ((reg & CANCTRL_REQOP_MASK) != CANCTRL_REQOP_CONF)
645 		return -ENODEV;
646 
647 	return 0;
648 }
649 
650 static int mcp251x_hw_probe(struct spi_device *spi)
651 {
652 	u8 ctrl;
653 	int ret;
654 
655 	ret = mcp251x_hw_reset(spi);
656 	if (ret)
657 		return ret;
658 
659 	ctrl = mcp251x_read_reg(spi, CANCTRL);
660 
661 	dev_dbg(&spi->dev, "CANCTRL 0x%02x\n", ctrl);
662 
663 	/* Check for power up default value */
664 	if ((ctrl & 0x17) != 0x07)
665 		return -ENODEV;
666 
667 	return 0;
668 }
669 
670 static int mcp251x_power_enable(struct regulator *reg, int enable)
671 {
672 	if (IS_ERR_OR_NULL(reg))
673 		return 0;
674 
675 	if (enable)
676 		return regulator_enable(reg);
677 	else
678 		return regulator_disable(reg);
679 }
680 
681 static void mcp251x_open_clean(struct net_device *net)
682 {
683 	struct mcp251x_priv *priv = netdev_priv(net);
684 	struct spi_device *spi = priv->spi;
685 
686 	free_irq(spi->irq, priv);
687 	mcp251x_hw_sleep(spi);
688 	mcp251x_power_enable(priv->transceiver, 0);
689 	close_candev(net);
690 }
691 
692 static int mcp251x_stop(struct net_device *net)
693 {
694 	struct mcp251x_priv *priv = netdev_priv(net);
695 	struct spi_device *spi = priv->spi;
696 
697 	close_candev(net);
698 
699 	priv->force_quit = 1;
700 	free_irq(spi->irq, priv);
701 	destroy_workqueue(priv->wq);
702 	priv->wq = NULL;
703 
704 	mutex_lock(&priv->mcp_lock);
705 
706 	/* Disable and clear pending interrupts */
707 	mcp251x_write_reg(spi, CANINTE, 0x00);
708 	mcp251x_write_reg(spi, CANINTF, 0x00);
709 
710 	mcp251x_write_reg(spi, TXBCTRL(0), 0);
711 	mcp251x_clean(net);
712 
713 	mcp251x_hw_sleep(spi);
714 
715 	mcp251x_power_enable(priv->transceiver, 0);
716 
717 	priv->can.state = CAN_STATE_STOPPED;
718 
719 	mutex_unlock(&priv->mcp_lock);
720 
721 	can_led_event(net, CAN_LED_EVENT_STOP);
722 
723 	return 0;
724 }
725 
726 static void mcp251x_error_skb(struct net_device *net, int can_id, int data1)
727 {
728 	struct sk_buff *skb;
729 	struct can_frame *frame;
730 
731 	skb = alloc_can_err_skb(net, &frame);
732 	if (skb) {
733 		frame->can_id |= can_id;
734 		frame->data[1] = data1;
735 		netif_rx_ni(skb);
736 	} else {
737 		netdev_err(net, "cannot allocate error skb\n");
738 	}
739 }
740 
741 static void mcp251x_tx_work_handler(struct work_struct *ws)
742 {
743 	struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv,
744 						 tx_work);
745 	struct spi_device *spi = priv->spi;
746 	struct net_device *net = priv->net;
747 	struct can_frame *frame;
748 
749 	mutex_lock(&priv->mcp_lock);
750 	if (priv->tx_skb) {
751 		if (priv->can.state == CAN_STATE_BUS_OFF) {
752 			mcp251x_clean(net);
753 		} else {
754 			frame = (struct can_frame *)priv->tx_skb->data;
755 
756 			if (frame->can_dlc > CAN_FRAME_MAX_DATA_LEN)
757 				frame->can_dlc = CAN_FRAME_MAX_DATA_LEN;
758 			mcp251x_hw_tx(spi, frame, 0);
759 			priv->tx_len = 1 + frame->can_dlc;
760 			can_put_echo_skb(priv->tx_skb, net, 0);
761 			priv->tx_skb = NULL;
762 		}
763 	}
764 	mutex_unlock(&priv->mcp_lock);
765 }
766 
767 static void mcp251x_restart_work_handler(struct work_struct *ws)
768 {
769 	struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv,
770 						 restart_work);
771 	struct spi_device *spi = priv->spi;
772 	struct net_device *net = priv->net;
773 
774 	mutex_lock(&priv->mcp_lock);
775 	if (priv->after_suspend) {
776 		mcp251x_hw_reset(spi);
777 		mcp251x_setup(net, priv, spi);
778 		if (priv->after_suspend & AFTER_SUSPEND_RESTART) {
779 			mcp251x_set_normal_mode(spi);
780 		} else if (priv->after_suspend & AFTER_SUSPEND_UP) {
781 			netif_device_attach(net);
782 			mcp251x_clean(net);
783 			mcp251x_set_normal_mode(spi);
784 			netif_wake_queue(net);
785 		} else {
786 			mcp251x_hw_sleep(spi);
787 		}
788 		priv->after_suspend = 0;
789 		priv->force_quit = 0;
790 	}
791 
792 	if (priv->restart_tx) {
793 		priv->restart_tx = 0;
794 		mcp251x_write_reg(spi, TXBCTRL(0), 0);
795 		mcp251x_clean(net);
796 		netif_wake_queue(net);
797 		mcp251x_error_skb(net, CAN_ERR_RESTARTED, 0);
798 	}
799 	mutex_unlock(&priv->mcp_lock);
800 }
801 
802 static irqreturn_t mcp251x_can_ist(int irq, void *dev_id)
803 {
804 	struct mcp251x_priv *priv = dev_id;
805 	struct spi_device *spi = priv->spi;
806 	struct net_device *net = priv->net;
807 
808 	mutex_lock(&priv->mcp_lock);
809 	while (!priv->force_quit) {
810 		enum can_state new_state;
811 		u8 intf, eflag;
812 		u8 clear_intf = 0;
813 		int can_id = 0, data1 = 0;
814 
815 		mcp251x_read_2regs(spi, CANINTF, &intf, &eflag);
816 
817 		/* mask out flags we don't care about */
818 		intf &= CANINTF_RX | CANINTF_TX | CANINTF_ERR;
819 
820 		/* receive buffer 0 */
821 		if (intf & CANINTF_RX0IF) {
822 			mcp251x_hw_rx(spi, 0);
823 			/*
824 			 * Free one buffer ASAP
825 			 * (The MCP2515 does this automatically.)
826 			 */
827 			if (mcp251x_is_2510(spi))
828 				mcp251x_write_bits(spi, CANINTF, CANINTF_RX0IF, 0x00);
829 		}
830 
831 		/* receive buffer 1 */
832 		if (intf & CANINTF_RX1IF) {
833 			mcp251x_hw_rx(spi, 1);
834 			/* the MCP2515 does this automatically */
835 			if (mcp251x_is_2510(spi))
836 				clear_intf |= CANINTF_RX1IF;
837 		}
838 
839 		/* any error or tx interrupt we need to clear? */
840 		if (intf & (CANINTF_ERR | CANINTF_TX))
841 			clear_intf |= intf & (CANINTF_ERR | CANINTF_TX);
842 		if (clear_intf)
843 			mcp251x_write_bits(spi, CANINTF, clear_intf, 0x00);
844 
845 		if (eflag)
846 			mcp251x_write_bits(spi, EFLG, eflag, 0x00);
847 
848 		/* Update can state */
849 		if (eflag & EFLG_TXBO) {
850 			new_state = CAN_STATE_BUS_OFF;
851 			can_id |= CAN_ERR_BUSOFF;
852 		} else if (eflag & EFLG_TXEP) {
853 			new_state = CAN_STATE_ERROR_PASSIVE;
854 			can_id |= CAN_ERR_CRTL;
855 			data1 |= CAN_ERR_CRTL_TX_PASSIVE;
856 		} else if (eflag & EFLG_RXEP) {
857 			new_state = CAN_STATE_ERROR_PASSIVE;
858 			can_id |= CAN_ERR_CRTL;
859 			data1 |= CAN_ERR_CRTL_RX_PASSIVE;
860 		} else if (eflag & EFLG_TXWAR) {
861 			new_state = CAN_STATE_ERROR_WARNING;
862 			can_id |= CAN_ERR_CRTL;
863 			data1 |= CAN_ERR_CRTL_TX_WARNING;
864 		} else if (eflag & EFLG_RXWAR) {
865 			new_state = CAN_STATE_ERROR_WARNING;
866 			can_id |= CAN_ERR_CRTL;
867 			data1 |= CAN_ERR_CRTL_RX_WARNING;
868 		} else {
869 			new_state = CAN_STATE_ERROR_ACTIVE;
870 		}
871 
872 		/* Update can state statistics */
873 		switch (priv->can.state) {
874 		case CAN_STATE_ERROR_ACTIVE:
875 			if (new_state >= CAN_STATE_ERROR_WARNING &&
876 			    new_state <= CAN_STATE_BUS_OFF)
877 				priv->can.can_stats.error_warning++;
878 		case CAN_STATE_ERROR_WARNING:	/* fallthrough */
879 			if (new_state >= CAN_STATE_ERROR_PASSIVE &&
880 			    new_state <= CAN_STATE_BUS_OFF)
881 				priv->can.can_stats.error_passive++;
882 			break;
883 		default:
884 			break;
885 		}
886 		priv->can.state = new_state;
887 
888 		if (intf & CANINTF_ERRIF) {
889 			/* Handle overflow counters */
890 			if (eflag & (EFLG_RX0OVR | EFLG_RX1OVR)) {
891 				if (eflag & EFLG_RX0OVR) {
892 					net->stats.rx_over_errors++;
893 					net->stats.rx_errors++;
894 				}
895 				if (eflag & EFLG_RX1OVR) {
896 					net->stats.rx_over_errors++;
897 					net->stats.rx_errors++;
898 				}
899 				can_id |= CAN_ERR_CRTL;
900 				data1 |= CAN_ERR_CRTL_RX_OVERFLOW;
901 			}
902 			mcp251x_error_skb(net, can_id, data1);
903 		}
904 
905 		if (priv->can.state == CAN_STATE_BUS_OFF) {
906 			if (priv->can.restart_ms == 0) {
907 				priv->force_quit = 1;
908 				priv->can.can_stats.bus_off++;
909 				can_bus_off(net);
910 				mcp251x_hw_sleep(spi);
911 				break;
912 			}
913 		}
914 
915 		if (intf == 0)
916 			break;
917 
918 		if (intf & CANINTF_TX) {
919 			net->stats.tx_packets++;
920 			net->stats.tx_bytes += priv->tx_len - 1;
921 			can_led_event(net, CAN_LED_EVENT_TX);
922 			if (priv->tx_len) {
923 				can_get_echo_skb(net, 0);
924 				priv->tx_len = 0;
925 			}
926 			netif_wake_queue(net);
927 		}
928 
929 	}
930 	mutex_unlock(&priv->mcp_lock);
931 	return IRQ_HANDLED;
932 }
933 
934 static int mcp251x_open(struct net_device *net)
935 {
936 	struct mcp251x_priv *priv = netdev_priv(net);
937 	struct spi_device *spi = priv->spi;
938 	unsigned long flags = IRQF_ONESHOT | IRQF_TRIGGER_FALLING;
939 	int ret;
940 
941 	ret = open_candev(net);
942 	if (ret) {
943 		dev_err(&spi->dev, "unable to set initial baudrate!\n");
944 		return ret;
945 	}
946 
947 	mutex_lock(&priv->mcp_lock);
948 	mcp251x_power_enable(priv->transceiver, 1);
949 
950 	priv->force_quit = 0;
951 	priv->tx_skb = NULL;
952 	priv->tx_len = 0;
953 
954 	ret = request_threaded_irq(spi->irq, NULL, mcp251x_can_ist,
955 				   flags | IRQF_ONESHOT, DEVICE_NAME, priv);
956 	if (ret) {
957 		dev_err(&spi->dev, "failed to acquire irq %d\n", spi->irq);
958 		mcp251x_power_enable(priv->transceiver, 0);
959 		close_candev(net);
960 		goto open_unlock;
961 	}
962 
963 	priv->wq = create_freezable_workqueue("mcp251x_wq");
964 	INIT_WORK(&priv->tx_work, mcp251x_tx_work_handler);
965 	INIT_WORK(&priv->restart_work, mcp251x_restart_work_handler);
966 
967 	ret = mcp251x_hw_reset(spi);
968 	if (ret) {
969 		mcp251x_open_clean(net);
970 		goto open_unlock;
971 	}
972 	ret = mcp251x_setup(net, priv, spi);
973 	if (ret) {
974 		mcp251x_open_clean(net);
975 		goto open_unlock;
976 	}
977 	ret = mcp251x_set_normal_mode(spi);
978 	if (ret) {
979 		mcp251x_open_clean(net);
980 		goto open_unlock;
981 	}
982 
983 	can_led_event(net, CAN_LED_EVENT_OPEN);
984 
985 	netif_wake_queue(net);
986 
987 open_unlock:
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 };
1010 MODULE_DEVICE_TABLE(of, mcp251x_of_match);
1011 
1012 static const struct spi_device_id mcp251x_id_table[] = {
1013 	{
1014 		.name		= "mcp2510",
1015 		.driver_data	= (kernel_ulong_t)CAN_MCP251X_MCP2510,
1016 	},
1017 	{
1018 		.name		= "mcp2515",
1019 		.driver_data	= (kernel_ulong_t)CAN_MCP251X_MCP2515,
1020 	},
1021 	{ }
1022 };
1023 MODULE_DEVICE_TABLE(spi, mcp251x_id_table);
1024 
1025 static int mcp251x_can_probe(struct spi_device *spi)
1026 {
1027 	const struct of_device_id *of_id = of_match_device(mcp251x_of_match,
1028 							   &spi->dev);
1029 	struct mcp251x_platform_data *pdata = dev_get_platdata(&spi->dev);
1030 	struct net_device *net;
1031 	struct mcp251x_priv *priv;
1032 	struct clk *clk;
1033 	int freq, ret;
1034 
1035 	clk = devm_clk_get(&spi->dev, NULL);
1036 	if (IS_ERR(clk)) {
1037 		if (pdata)
1038 			freq = pdata->oscillator_frequency;
1039 		else
1040 			return PTR_ERR(clk);
1041 	} else {
1042 		freq = clk_get_rate(clk);
1043 	}
1044 
1045 	/* Sanity check */
1046 	if (freq < 1000000 || freq > 25000000)
1047 		return -ERANGE;
1048 
1049 	/* Allocate can/net device */
1050 	net = alloc_candev(sizeof(struct mcp251x_priv), TX_ECHO_SKB_MAX);
1051 	if (!net)
1052 		return -ENOMEM;
1053 
1054 	if (!IS_ERR(clk)) {
1055 		ret = clk_prepare_enable(clk);
1056 		if (ret)
1057 			goto out_free;
1058 	}
1059 
1060 	net->netdev_ops = &mcp251x_netdev_ops;
1061 	net->flags |= IFF_ECHO;
1062 
1063 	priv = netdev_priv(net);
1064 	priv->can.bittiming_const = &mcp251x_bittiming_const;
1065 	priv->can.do_set_mode = mcp251x_do_set_mode;
1066 	priv->can.clock.freq = freq / 2;
1067 	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
1068 		CAN_CTRLMODE_LOOPBACK | CAN_CTRLMODE_LISTENONLY;
1069 	if (of_id)
1070 		priv->model = (enum mcp251x_model)of_id->data;
1071 	else
1072 		priv->model = spi_get_device_id(spi)->driver_data;
1073 	priv->net = net;
1074 	priv->clk = clk;
1075 
1076 	spi_set_drvdata(spi, priv);
1077 
1078 	/* Configure the SPI bus */
1079 	spi->bits_per_word = 8;
1080 	if (mcp251x_is_2510(spi))
1081 		spi->max_speed_hz = spi->max_speed_hz ? : 5 * 1000 * 1000;
1082 	else
1083 		spi->max_speed_hz = spi->max_speed_hz ? : 10 * 1000 * 1000;
1084 	ret = spi_setup(spi);
1085 	if (ret)
1086 		goto out_clk;
1087 
1088 	priv->power = devm_regulator_get(&spi->dev, "vdd");
1089 	priv->transceiver = devm_regulator_get(&spi->dev, "xceiver");
1090 	if ((PTR_ERR(priv->power) == -EPROBE_DEFER) ||
1091 	    (PTR_ERR(priv->transceiver) == -EPROBE_DEFER)) {
1092 		ret = -EPROBE_DEFER;
1093 		goto out_clk;
1094 	}
1095 
1096 	ret = mcp251x_power_enable(priv->power, 1);
1097 	if (ret)
1098 		goto out_clk;
1099 
1100 	priv->spi = spi;
1101 	mutex_init(&priv->mcp_lock);
1102 
1103 	/* If requested, allocate DMA buffers */
1104 	if (mcp251x_enable_dma) {
1105 		spi->dev.coherent_dma_mask = ~0;
1106 
1107 		/*
1108 		 * Minimum coherent DMA allocation is PAGE_SIZE, so allocate
1109 		 * that much and share it between Tx and Rx DMA buffers.
1110 		 */
1111 		priv->spi_tx_buf = dmam_alloc_coherent(&spi->dev,
1112 						       PAGE_SIZE,
1113 						       &priv->spi_tx_dma,
1114 						       GFP_DMA);
1115 
1116 		if (priv->spi_tx_buf) {
1117 			priv->spi_rx_buf = (priv->spi_tx_buf + (PAGE_SIZE / 2));
1118 			priv->spi_rx_dma = (dma_addr_t)(priv->spi_tx_dma +
1119 							(PAGE_SIZE / 2));
1120 		} else {
1121 			/* Fall back to non-DMA */
1122 			mcp251x_enable_dma = 0;
1123 		}
1124 	}
1125 
1126 	/* Allocate non-DMA buffers */
1127 	if (!mcp251x_enable_dma) {
1128 		priv->spi_tx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,
1129 						GFP_KERNEL);
1130 		if (!priv->spi_tx_buf) {
1131 			ret = -ENOMEM;
1132 			goto error_probe;
1133 		}
1134 		priv->spi_rx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,
1135 						GFP_KERNEL);
1136 		if (!priv->spi_rx_buf) {
1137 			ret = -ENOMEM;
1138 			goto error_probe;
1139 		}
1140 	}
1141 
1142 	SET_NETDEV_DEV(net, &spi->dev);
1143 
1144 	/* Here is OK to not lock the MCP, no one knows about it yet */
1145 	ret = mcp251x_hw_probe(spi);
1146 	if (ret)
1147 		goto error_probe;
1148 
1149 	mcp251x_hw_sleep(spi);
1150 
1151 	ret = register_candev(net);
1152 	if (ret)
1153 		goto error_probe;
1154 
1155 	devm_can_led_init(net);
1156 
1157 	return 0;
1158 
1159 error_probe:
1160 	mcp251x_power_enable(priv->power, 0);
1161 
1162 out_clk:
1163 	if (!IS_ERR(clk))
1164 		clk_disable_unprepare(clk);
1165 
1166 out_free:
1167 	free_candev(net);
1168 
1169 	return ret;
1170 }
1171 
1172 static int mcp251x_can_remove(struct spi_device *spi)
1173 {
1174 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
1175 	struct net_device *net = priv->net;
1176 
1177 	unregister_candev(net);
1178 
1179 	mcp251x_power_enable(priv->power, 0);
1180 
1181 	if (!IS_ERR(priv->clk))
1182 		clk_disable_unprepare(priv->clk);
1183 
1184 	free_candev(net);
1185 
1186 	return 0;
1187 }
1188 
1189 static int __maybe_unused mcp251x_can_suspend(struct device *dev)
1190 {
1191 	struct spi_device *spi = to_spi_device(dev);
1192 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
1193 	struct net_device *net = priv->net;
1194 
1195 	priv->force_quit = 1;
1196 	disable_irq(spi->irq);
1197 	/*
1198 	 * Note: at this point neither IST nor workqueues are running.
1199 	 * open/stop cannot be called anyway so locking is not needed
1200 	 */
1201 	if (netif_running(net)) {
1202 		netif_device_detach(net);
1203 
1204 		mcp251x_hw_sleep(spi);
1205 		mcp251x_power_enable(priv->transceiver, 0);
1206 		priv->after_suspend = AFTER_SUSPEND_UP;
1207 	} else {
1208 		priv->after_suspend = AFTER_SUSPEND_DOWN;
1209 	}
1210 
1211 	if (!IS_ERR_OR_NULL(priv->power)) {
1212 		regulator_disable(priv->power);
1213 		priv->after_suspend |= AFTER_SUSPEND_POWER;
1214 	}
1215 
1216 	return 0;
1217 }
1218 
1219 static int __maybe_unused mcp251x_can_resume(struct device *dev)
1220 {
1221 	struct spi_device *spi = to_spi_device(dev);
1222 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
1223 
1224 	if (priv->after_suspend & AFTER_SUSPEND_POWER) {
1225 		mcp251x_power_enable(priv->power, 1);
1226 		queue_work(priv->wq, &priv->restart_work);
1227 	} else {
1228 		if (priv->after_suspend & AFTER_SUSPEND_UP) {
1229 			mcp251x_power_enable(priv->transceiver, 1);
1230 			queue_work(priv->wq, &priv->restart_work);
1231 		} else {
1232 			priv->after_suspend = 0;
1233 		}
1234 	}
1235 	priv->force_quit = 0;
1236 	enable_irq(spi->irq);
1237 	return 0;
1238 }
1239 
1240 static SIMPLE_DEV_PM_OPS(mcp251x_can_pm_ops, mcp251x_can_suspend,
1241 	mcp251x_can_resume);
1242 
1243 static struct spi_driver mcp251x_can_driver = {
1244 	.driver = {
1245 		.name = DEVICE_NAME,
1246 		.owner = THIS_MODULE,
1247 		.of_match_table = mcp251x_of_match,
1248 		.pm = &mcp251x_can_pm_ops,
1249 	},
1250 	.id_table = mcp251x_id_table,
1251 	.probe = mcp251x_can_probe,
1252 	.remove = mcp251x_can_remove,
1253 };
1254 module_spi_driver(mcp251x_can_driver);
1255 
1256 MODULE_AUTHOR("Chris Elston <celston@katalix.com>, "
1257 	      "Christian Pellegrin <chripell@evolware.org>");
1258 MODULE_DESCRIPTION("Microchip 251x CAN driver");
1259 MODULE_LICENSE("GPL v2");
1260