2 * CAN bus driver for Microchip 251x CAN Controller with SPI Interface
4 * MCP2510 support and bug fixes by Christian Pellegrin
5 * <chripell@evolware.org>
7 * Copyright 2009 Christian Pellegrin EVOL S.r.l.
9 * Copyright 2007 Raymarine UK, Ltd. All Rights Reserved.
10 * Written under contract by:
11 * Chris Elston, Katalix Systems, Ltd.
13 * Based on Microchip MCP251x CAN controller driver written by
14 * David Vrabel, Copyright 2006 Arcom Control Systems Ltd.
16 * Based on CAN bus driver for the CCAN controller written by
17 * - Sascha Hauer, Marc Kleine-Budde, Pengutronix
18 * - Simon Kallweit, intefo AG
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
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.
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/>.
35 * Your platform definition file should specify something like:
37 * static struct mcp251x_platform_data mcp251x_info = {
38 * .oscillator_frequency = 8000000,
41 * static struct spi_board_info spi_board_info[] = {
43 * .modalias = "mcp2510",
44 * // or "mcp2515" depending on your controller
45 * .platform_data = &mcp251x_info,
47 * .max_speed_hz = 2*1000*1000,
52 * Please see mcp251x.h for a description of the fields in
53 * struct mcp251x_platform_data.
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>
69 #include <linux/kernel.h>
70 #include <linux/module.h>
71 #include <linux/netdevice.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>
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
90 #define INSTRUCTION_RTS(n) (0x80 | ((n) & 0x07))
93 /* MPC251x registers */
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
107 # define CNF1_SJW_SHIFT 6
109 # define CNF2_BTLMODE 0x80
110 # define CNF2_SAM 0x40
111 # define CNF2_PS1_SHIFT 3
113 # define CNF3_SOF 0x08
114 # define CNF3_WAKFIL 0x04
115 # define CNF3_PHSEG2_MASK 0x07
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
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)
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
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
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)
202 #define GET_BYTE(val, byte) \
203 (((val) >> ((byte) * 8)) & 0xff)
204 #define SET_BYTE(val, byte) \
205 (((val) & 0xff) << ((byte) * 8))
208 * Buffer size required for the largest SPI transfer (i.e., reading a
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
215 #define TX_ECHO_SKB_MAX 1
217 #define DEVICE_NAME "mcp251x"
219 static int mcp251x_enable_dma
; /* Enable SPI DMA. Default: 0 (Off) */
220 module_param(mcp251x_enable_dma
, int, S_IRUGO
);
221 MODULE_PARM_DESC(mcp251x_enable_dma
, "Enable SPI DMA. Default: 0 (Off)");
223 static const struct can_bittiming_const mcp251x_bittiming_const
= {
236 CAN_MCP251X_MCP2510
= 0x2510,
237 CAN_MCP251X_MCP2515
= 0x2515,
240 struct mcp251x_priv
{
242 struct net_device
*net
;
243 struct spi_device
*spi
;
244 enum mcp251x_model model
;
246 struct mutex mcp_lock
; /* SPI device lock */
250 dma_addr_t spi_tx_dma
;
251 dma_addr_t spi_rx_dma
;
253 struct sk_buff
*tx_skb
;
256 struct workqueue_struct
*wq
;
257 struct work_struct tx_work
;
258 struct work_struct restart_work
;
262 #define AFTER_SUSPEND_UP 1
263 #define AFTER_SUSPEND_DOWN 2
264 #define AFTER_SUSPEND_POWER 4
265 #define AFTER_SUSPEND_RESTART 8
267 struct regulator
*power
;
268 struct regulator
*transceiver
;
272 #define MCP251X_IS(_model) \
273 static inline int mcp251x_is_##_model(struct spi_device *spi) \
275 struct mcp251x_priv *priv = spi_get_drvdata(spi); \
276 return priv->model == CAN_MCP251X_MCP##_model; \
282 static void mcp251x_clean(struct net_device
*net
)
284 struct mcp251x_priv
*priv
= netdev_priv(net
);
286 if (priv
->tx_skb
|| priv
->tx_len
)
287 net
->stats
.tx_errors
++;
289 dev_kfree_skb(priv
->tx_skb
);
291 can_free_echo_skb(priv
->net
, 0);
297 * Note about handling of error return of mcp251x_spi_trans: accessing
298 * registers via SPI is not really different conceptually than using
299 * normal I/O assembler instructions, although it's much more
300 * complicated from a practical POV. So it's not advisable to always
301 * check the return value of this function. Imagine that every
302 * read{b,l}, write{b,l} and friends would be bracketed in "if ( < 0)
303 * error();", it would be a great mess (well there are some situation
304 * when exception handling C++ like could be useful after all). So we
305 * just check that transfers are OK at the beginning of our
306 * conversation with the chip and to avoid doing really nasty things
307 * (like injecting bogus packets in the network stack).
309 static int mcp251x_spi_trans(struct spi_device
*spi
, int len
)
311 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
312 struct spi_transfer t
= {
313 .tx_buf
= priv
->spi_tx_buf
,
314 .rx_buf
= priv
->spi_rx_buf
,
318 struct spi_message m
;
321 spi_message_init(&m
);
323 if (mcp251x_enable_dma
) {
324 t
.tx_dma
= priv
->spi_tx_dma
;
325 t
.rx_dma
= priv
->spi_rx_dma
;
329 spi_message_add_tail(&t
, &m
);
331 ret
= spi_sync(spi
, &m
);
333 dev_err(&spi
->dev
, "spi transfer failed: ret = %d\n", ret
);
337 static u8
mcp251x_read_reg(struct spi_device
*spi
, uint8_t reg
)
339 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
342 priv
->spi_tx_buf
[0] = INSTRUCTION_READ
;
343 priv
->spi_tx_buf
[1] = reg
;
345 mcp251x_spi_trans(spi
, 3);
346 val
= priv
->spi_rx_buf
[2];
351 static void mcp251x_read_2regs(struct spi_device
*spi
, uint8_t reg
,
352 uint8_t *v1
, uint8_t *v2
)
354 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
356 priv
->spi_tx_buf
[0] = INSTRUCTION_READ
;
357 priv
->spi_tx_buf
[1] = reg
;
359 mcp251x_spi_trans(spi
, 4);
361 *v1
= priv
->spi_rx_buf
[2];
362 *v2
= priv
->spi_rx_buf
[3];
365 static void mcp251x_write_reg(struct spi_device
*spi
, u8 reg
, uint8_t val
)
367 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
369 priv
->spi_tx_buf
[0] = INSTRUCTION_WRITE
;
370 priv
->spi_tx_buf
[1] = reg
;
371 priv
->spi_tx_buf
[2] = val
;
373 mcp251x_spi_trans(spi
, 3);
376 static void mcp251x_write_bits(struct spi_device
*spi
, u8 reg
,
377 u8 mask
, uint8_t val
)
379 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
381 priv
->spi_tx_buf
[0] = INSTRUCTION_BIT_MODIFY
;
382 priv
->spi_tx_buf
[1] = reg
;
383 priv
->spi_tx_buf
[2] = mask
;
384 priv
->spi_tx_buf
[3] = val
;
386 mcp251x_spi_trans(spi
, 4);
389 static void mcp251x_hw_tx_frame(struct spi_device
*spi
, u8
*buf
,
390 int len
, int tx_buf_idx
)
392 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
394 if (mcp251x_is_2510(spi
)) {
397 for (i
= 1; i
< TXBDAT_OFF
+ len
; i
++)
398 mcp251x_write_reg(spi
, TXBCTRL(tx_buf_idx
) + i
,
401 memcpy(priv
->spi_tx_buf
, buf
, TXBDAT_OFF
+ len
);
402 mcp251x_spi_trans(spi
, TXBDAT_OFF
+ len
);
406 static void mcp251x_hw_tx(struct spi_device
*spi
, struct can_frame
*frame
,
409 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
410 u32 sid
, eid
, exide
, rtr
;
411 u8 buf
[SPI_TRANSFER_BUF_LEN
];
413 exide
= (frame
->can_id
& CAN_EFF_FLAG
) ? 1 : 0; /* Extended ID Enable */
415 sid
= (frame
->can_id
& CAN_EFF_MASK
) >> 18;
417 sid
= frame
->can_id
& CAN_SFF_MASK
; /* Standard ID */
418 eid
= frame
->can_id
& CAN_EFF_MASK
; /* Extended ID */
419 rtr
= (frame
->can_id
& CAN_RTR_FLAG
) ? 1 : 0; /* Remote transmission */
421 buf
[TXBCTRL_OFF
] = INSTRUCTION_LOAD_TXB(tx_buf_idx
);
422 buf
[TXBSIDH_OFF
] = sid
>> SIDH_SHIFT
;
423 buf
[TXBSIDL_OFF
] = ((sid
& SIDL_SID_MASK
) << SIDL_SID_SHIFT
) |
424 (exide
<< SIDL_EXIDE_SHIFT
) |
425 ((eid
>> SIDL_EID_SHIFT
) & SIDL_EID_MASK
);
426 buf
[TXBEID8_OFF
] = GET_BYTE(eid
, 1);
427 buf
[TXBEID0_OFF
] = GET_BYTE(eid
, 0);
428 buf
[TXBDLC_OFF
] = (rtr
<< DLC_RTR_SHIFT
) | frame
->can_dlc
;
429 memcpy(buf
+ TXBDAT_OFF
, frame
->data
, frame
->can_dlc
);
430 mcp251x_hw_tx_frame(spi
, buf
, frame
->can_dlc
, tx_buf_idx
);
432 /* use INSTRUCTION_RTS, to avoid "repeated frame problem" */
433 priv
->spi_tx_buf
[0] = INSTRUCTION_RTS(1 << tx_buf_idx
);
434 mcp251x_spi_trans(priv
->spi
, 1);
437 static void mcp251x_hw_rx_frame(struct spi_device
*spi
, u8
*buf
,
440 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
442 if (mcp251x_is_2510(spi
)) {
445 for (i
= 1; i
< RXBDAT_OFF
; i
++)
446 buf
[i
] = mcp251x_read_reg(spi
, RXBCTRL(buf_idx
) + i
);
448 len
= get_can_dlc(buf
[RXBDLC_OFF
] & RXBDLC_LEN_MASK
);
449 for (; i
< (RXBDAT_OFF
+ len
); i
++)
450 buf
[i
] = mcp251x_read_reg(spi
, RXBCTRL(buf_idx
) + i
);
452 priv
->spi_tx_buf
[RXBCTRL_OFF
] = INSTRUCTION_READ_RXB(buf_idx
);
453 mcp251x_spi_trans(spi
, SPI_TRANSFER_BUF_LEN
);
454 memcpy(buf
, priv
->spi_rx_buf
, SPI_TRANSFER_BUF_LEN
);
458 static void mcp251x_hw_rx(struct spi_device
*spi
, int buf_idx
)
460 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
462 struct can_frame
*frame
;
463 u8 buf
[SPI_TRANSFER_BUF_LEN
];
465 skb
= alloc_can_skb(priv
->net
, &frame
);
467 dev_err(&spi
->dev
, "cannot allocate RX skb\n");
468 priv
->net
->stats
.rx_dropped
++;
472 mcp251x_hw_rx_frame(spi
, buf
, buf_idx
);
473 if (buf
[RXBSIDL_OFF
] & RXBSIDL_IDE
) {
474 /* Extended ID format */
475 frame
->can_id
= CAN_EFF_FLAG
;
477 /* Extended ID part */
478 SET_BYTE(buf
[RXBSIDL_OFF
] & RXBSIDL_EID
, 2) |
479 SET_BYTE(buf
[RXBEID8_OFF
], 1) |
480 SET_BYTE(buf
[RXBEID0_OFF
], 0) |
481 /* Standard ID part */
482 (((buf
[RXBSIDH_OFF
] << RXBSIDH_SHIFT
) |
483 (buf
[RXBSIDL_OFF
] >> RXBSIDL_SHIFT
)) << 18);
484 /* Remote transmission request */
485 if (buf
[RXBDLC_OFF
] & RXBDLC_RTR
)
486 frame
->can_id
|= CAN_RTR_FLAG
;
488 /* Standard ID format */
490 (buf
[RXBSIDH_OFF
] << RXBSIDH_SHIFT
) |
491 (buf
[RXBSIDL_OFF
] >> RXBSIDL_SHIFT
);
492 if (buf
[RXBSIDL_OFF
] & RXBSIDL_SRR
)
493 frame
->can_id
|= CAN_RTR_FLAG
;
496 frame
->can_dlc
= get_can_dlc(buf
[RXBDLC_OFF
] & RXBDLC_LEN_MASK
);
497 memcpy(frame
->data
, buf
+ RXBDAT_OFF
, frame
->can_dlc
);
499 priv
->net
->stats
.rx_packets
++;
500 priv
->net
->stats
.rx_bytes
+= frame
->can_dlc
;
502 can_led_event(priv
->net
, CAN_LED_EVENT_RX
);
507 static void mcp251x_hw_sleep(struct spi_device
*spi
)
509 mcp251x_write_reg(spi
, CANCTRL
, CANCTRL_REQOP_SLEEP
);
512 static netdev_tx_t
mcp251x_hard_start_xmit(struct sk_buff
*skb
,
513 struct net_device
*net
)
515 struct mcp251x_priv
*priv
= netdev_priv(net
);
516 struct spi_device
*spi
= priv
->spi
;
518 if (priv
->tx_skb
|| priv
->tx_len
) {
519 dev_warn(&spi
->dev
, "hard_xmit called while tx busy\n");
520 return NETDEV_TX_BUSY
;
523 if (can_dropped_invalid_skb(net
, skb
))
526 netif_stop_queue(net
);
528 queue_work(priv
->wq
, &priv
->tx_work
);
533 static int mcp251x_do_set_mode(struct net_device
*net
, enum can_mode mode
)
535 struct mcp251x_priv
*priv
= netdev_priv(net
);
540 /* We have to delay work since SPI I/O may sleep */
541 priv
->can
.state
= CAN_STATE_ERROR_ACTIVE
;
542 priv
->restart_tx
= 1;
543 if (priv
->can
.restart_ms
== 0)
544 priv
->after_suspend
= AFTER_SUSPEND_RESTART
;
545 queue_work(priv
->wq
, &priv
->restart_work
);
554 static int mcp251x_set_normal_mode(struct spi_device
*spi
)
556 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
557 unsigned long timeout
;
559 /* Enable interrupts */
560 mcp251x_write_reg(spi
, CANINTE
,
561 CANINTE_ERRIE
| CANINTE_TX2IE
| CANINTE_TX1IE
|
562 CANINTE_TX0IE
| CANINTE_RX1IE
| CANINTE_RX0IE
);
564 if (priv
->can
.ctrlmode
& CAN_CTRLMODE_LOOPBACK
) {
565 /* Put device into loopback mode */
566 mcp251x_write_reg(spi
, CANCTRL
, CANCTRL_REQOP_LOOPBACK
);
567 } else if (priv
->can
.ctrlmode
& CAN_CTRLMODE_LISTENONLY
) {
568 /* Put device into listen-only mode */
569 mcp251x_write_reg(spi
, CANCTRL
, CANCTRL_REQOP_LISTEN_ONLY
);
571 /* Put device into normal mode */
572 mcp251x_write_reg(spi
, CANCTRL
, CANCTRL_REQOP_NORMAL
);
574 /* Wait for the device to enter normal mode */
575 timeout
= jiffies
+ HZ
;
576 while (mcp251x_read_reg(spi
, CANSTAT
) & CANCTRL_REQOP_MASK
) {
578 if (time_after(jiffies
, timeout
)) {
579 dev_err(&spi
->dev
, "MCP251x didn't"
580 " enter in normal mode\n");
585 priv
->can
.state
= CAN_STATE_ERROR_ACTIVE
;
589 static int mcp251x_do_set_bittiming(struct net_device
*net
)
591 struct mcp251x_priv
*priv
= netdev_priv(net
);
592 struct can_bittiming
*bt
= &priv
->can
.bittiming
;
593 struct spi_device
*spi
= priv
->spi
;
595 mcp251x_write_reg(spi
, CNF1
, ((bt
->sjw
- 1) << CNF1_SJW_SHIFT
) |
597 mcp251x_write_reg(spi
, CNF2
, CNF2_BTLMODE
|
598 (priv
->can
.ctrlmode
& CAN_CTRLMODE_3_SAMPLES
?
600 ((bt
->phase_seg1
- 1) << CNF2_PS1_SHIFT
) |
602 mcp251x_write_bits(spi
, CNF3
, CNF3_PHSEG2_MASK
,
603 (bt
->phase_seg2
- 1));
604 dev_info(&spi
->dev
, "CNF: 0x%02x 0x%02x 0x%02x\n",
605 mcp251x_read_reg(spi
, CNF1
),
606 mcp251x_read_reg(spi
, CNF2
),
607 mcp251x_read_reg(spi
, CNF3
));
612 static int mcp251x_setup(struct net_device
*net
, struct mcp251x_priv
*priv
,
613 struct spi_device
*spi
)
615 mcp251x_do_set_bittiming(net
);
617 mcp251x_write_reg(spi
, RXBCTRL(0),
618 RXBCTRL_BUKT
| RXBCTRL_RXM0
| RXBCTRL_RXM1
);
619 mcp251x_write_reg(spi
, RXBCTRL(1),
620 RXBCTRL_RXM0
| RXBCTRL_RXM1
);
624 static int mcp251x_hw_reset(struct spi_device
*spi
)
626 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
628 unsigned long timeout
;
630 priv
->spi_tx_buf
[0] = INSTRUCTION_RESET
;
631 ret
= spi_write(spi
, priv
->spi_tx_buf
, 1);
633 dev_err(&spi
->dev
, "reset failed: ret = %d\n", ret
);
637 /* Wait for reset to finish */
638 timeout
= jiffies
+ HZ
;
640 while ((mcp251x_read_reg(spi
, CANSTAT
) & CANCTRL_REQOP_MASK
)
641 != CANCTRL_REQOP_CONF
) {
643 if (time_after(jiffies
, timeout
)) {
644 dev_err(&spi
->dev
, "MCP251x didn't"
645 " enter in conf mode after reset\n");
652 static int mcp251x_hw_probe(struct spi_device
*spi
)
656 mcp251x_hw_reset(spi
);
659 * Please note that these are "magic values" based on after
660 * reset defaults taken from data sheet which allows us to see
661 * if we really have a chip on the bus (we avoid common all
662 * zeroes or all ones situations)
664 st1
= mcp251x_read_reg(spi
, CANSTAT
) & 0xEE;
665 st2
= mcp251x_read_reg(spi
, CANCTRL
) & 0x17;
667 dev_dbg(&spi
->dev
, "CANSTAT 0x%02x CANCTRL 0x%02x\n", st1
, st2
);
669 /* Check for power up default values */
670 return (st1
== 0x80 && st2
== 0x07) ? 1 : 0;
673 static int mcp251x_power_enable(struct regulator
*reg
, int enable
)
679 return regulator_enable(reg
);
681 return regulator_disable(reg
);
684 static void mcp251x_open_clean(struct net_device
*net
)
686 struct mcp251x_priv
*priv
= netdev_priv(net
);
687 struct spi_device
*spi
= priv
->spi
;
689 free_irq(spi
->irq
, priv
);
690 mcp251x_hw_sleep(spi
);
691 mcp251x_power_enable(priv
->transceiver
, 0);
695 static int mcp251x_stop(struct net_device
*net
)
697 struct mcp251x_priv
*priv
= netdev_priv(net
);
698 struct spi_device
*spi
= priv
->spi
;
702 priv
->force_quit
= 1;
703 free_irq(spi
->irq
, priv
);
704 destroy_workqueue(priv
->wq
);
707 mutex_lock(&priv
->mcp_lock
);
709 /* Disable and clear pending interrupts */
710 mcp251x_write_reg(spi
, CANINTE
, 0x00);
711 mcp251x_write_reg(spi
, CANINTF
, 0x00);
713 mcp251x_write_reg(spi
, TXBCTRL(0), 0);
716 mcp251x_hw_sleep(spi
);
718 mcp251x_power_enable(priv
->transceiver
, 0);
720 priv
->can
.state
= CAN_STATE_STOPPED
;
722 mutex_unlock(&priv
->mcp_lock
);
724 can_led_event(net
, CAN_LED_EVENT_STOP
);
729 static void mcp251x_error_skb(struct net_device
*net
, int can_id
, int data1
)
732 struct can_frame
*frame
;
734 skb
= alloc_can_err_skb(net
, &frame
);
736 frame
->can_id
|= can_id
;
737 frame
->data
[1] = data1
;
740 netdev_err(net
, "cannot allocate error skb\n");
744 static void mcp251x_tx_work_handler(struct work_struct
*ws
)
746 struct mcp251x_priv
*priv
= container_of(ws
, struct mcp251x_priv
,
748 struct spi_device
*spi
= priv
->spi
;
749 struct net_device
*net
= priv
->net
;
750 struct can_frame
*frame
;
752 mutex_lock(&priv
->mcp_lock
);
754 if (priv
->can
.state
== CAN_STATE_BUS_OFF
) {
757 frame
= (struct can_frame
*)priv
->tx_skb
->data
;
759 if (frame
->can_dlc
> CAN_FRAME_MAX_DATA_LEN
)
760 frame
->can_dlc
= CAN_FRAME_MAX_DATA_LEN
;
761 mcp251x_hw_tx(spi
, frame
, 0);
762 priv
->tx_len
= 1 + frame
->can_dlc
;
763 can_put_echo_skb(priv
->tx_skb
, net
, 0);
767 mutex_unlock(&priv
->mcp_lock
);
770 static void mcp251x_restart_work_handler(struct work_struct
*ws
)
772 struct mcp251x_priv
*priv
= container_of(ws
, struct mcp251x_priv
,
774 struct spi_device
*spi
= priv
->spi
;
775 struct net_device
*net
= priv
->net
;
777 mutex_lock(&priv
->mcp_lock
);
778 if (priv
->after_suspend
) {
780 mcp251x_hw_reset(spi
);
781 mcp251x_setup(net
, priv
, spi
);
782 if (priv
->after_suspend
& AFTER_SUSPEND_RESTART
) {
783 mcp251x_set_normal_mode(spi
);
784 } else if (priv
->after_suspend
& AFTER_SUSPEND_UP
) {
785 netif_device_attach(net
);
787 mcp251x_set_normal_mode(spi
);
788 netif_wake_queue(net
);
790 mcp251x_hw_sleep(spi
);
792 priv
->after_suspend
= 0;
793 priv
->force_quit
= 0;
796 if (priv
->restart_tx
) {
797 priv
->restart_tx
= 0;
798 mcp251x_write_reg(spi
, TXBCTRL(0), 0);
800 netif_wake_queue(net
);
801 mcp251x_error_skb(net
, CAN_ERR_RESTARTED
, 0);
803 mutex_unlock(&priv
->mcp_lock
);
806 static irqreturn_t
mcp251x_can_ist(int irq
, void *dev_id
)
808 struct mcp251x_priv
*priv
= dev_id
;
809 struct spi_device
*spi
= priv
->spi
;
810 struct net_device
*net
= priv
->net
;
812 mutex_lock(&priv
->mcp_lock
);
813 while (!priv
->force_quit
) {
814 enum can_state new_state
;
817 int can_id
= 0, data1
= 0;
819 mcp251x_read_2regs(spi
, CANINTF
, &intf
, &eflag
);
821 /* mask out flags we don't care about */
822 intf
&= CANINTF_RX
| CANINTF_TX
| CANINTF_ERR
;
824 /* receive buffer 0 */
825 if (intf
& CANINTF_RX0IF
) {
826 mcp251x_hw_rx(spi
, 0);
828 * Free one buffer ASAP
829 * (The MCP2515 does this automatically.)
831 if (mcp251x_is_2510(spi
))
832 mcp251x_write_bits(spi
, CANINTF
, CANINTF_RX0IF
, 0x00);
835 /* receive buffer 1 */
836 if (intf
& CANINTF_RX1IF
) {
837 mcp251x_hw_rx(spi
, 1);
838 /* the MCP2515 does this automatically */
839 if (mcp251x_is_2510(spi
))
840 clear_intf
|= CANINTF_RX1IF
;
843 /* any error or tx interrupt we need to clear? */
844 if (intf
& (CANINTF_ERR
| CANINTF_TX
))
845 clear_intf
|= intf
& (CANINTF_ERR
| CANINTF_TX
);
847 mcp251x_write_bits(spi
, CANINTF
, clear_intf
, 0x00);
850 mcp251x_write_bits(spi
, EFLG
, eflag
, 0x00);
852 /* Update can state */
853 if (eflag
& EFLG_TXBO
) {
854 new_state
= CAN_STATE_BUS_OFF
;
855 can_id
|= CAN_ERR_BUSOFF
;
856 } else if (eflag
& EFLG_TXEP
) {
857 new_state
= CAN_STATE_ERROR_PASSIVE
;
858 can_id
|= CAN_ERR_CRTL
;
859 data1
|= CAN_ERR_CRTL_TX_PASSIVE
;
860 } else if (eflag
& EFLG_RXEP
) {
861 new_state
= CAN_STATE_ERROR_PASSIVE
;
862 can_id
|= CAN_ERR_CRTL
;
863 data1
|= CAN_ERR_CRTL_RX_PASSIVE
;
864 } else if (eflag
& EFLG_TXWAR
) {
865 new_state
= CAN_STATE_ERROR_WARNING
;
866 can_id
|= CAN_ERR_CRTL
;
867 data1
|= CAN_ERR_CRTL_TX_WARNING
;
868 } else if (eflag
& EFLG_RXWAR
) {
869 new_state
= CAN_STATE_ERROR_WARNING
;
870 can_id
|= CAN_ERR_CRTL
;
871 data1
|= CAN_ERR_CRTL_RX_WARNING
;
873 new_state
= CAN_STATE_ERROR_ACTIVE
;
876 /* Update can state statistics */
877 switch (priv
->can
.state
) {
878 case CAN_STATE_ERROR_ACTIVE
:
879 if (new_state
>= CAN_STATE_ERROR_WARNING
&&
880 new_state
<= CAN_STATE_BUS_OFF
)
881 priv
->can
.can_stats
.error_warning
++;
882 case CAN_STATE_ERROR_WARNING
: /* fallthrough */
883 if (new_state
>= CAN_STATE_ERROR_PASSIVE
&&
884 new_state
<= CAN_STATE_BUS_OFF
)
885 priv
->can
.can_stats
.error_passive
++;
890 priv
->can
.state
= new_state
;
892 if (intf
& CANINTF_ERRIF
) {
893 /* Handle overflow counters */
894 if (eflag
& (EFLG_RX0OVR
| EFLG_RX1OVR
)) {
895 if (eflag
& EFLG_RX0OVR
) {
896 net
->stats
.rx_over_errors
++;
897 net
->stats
.rx_errors
++;
899 if (eflag
& EFLG_RX1OVR
) {
900 net
->stats
.rx_over_errors
++;
901 net
->stats
.rx_errors
++;
903 can_id
|= CAN_ERR_CRTL
;
904 data1
|= CAN_ERR_CRTL_RX_OVERFLOW
;
906 mcp251x_error_skb(net
, can_id
, data1
);
909 if (priv
->can
.state
== CAN_STATE_BUS_OFF
) {
910 if (priv
->can
.restart_ms
== 0) {
911 priv
->force_quit
= 1;
913 mcp251x_hw_sleep(spi
);
921 if (intf
& CANINTF_TX
) {
922 net
->stats
.tx_packets
++;
923 net
->stats
.tx_bytes
+= priv
->tx_len
- 1;
924 can_led_event(net
, CAN_LED_EVENT_TX
);
926 can_get_echo_skb(net
, 0);
929 netif_wake_queue(net
);
933 mutex_unlock(&priv
->mcp_lock
);
937 static int mcp251x_open(struct net_device
*net
)
939 struct mcp251x_priv
*priv
= netdev_priv(net
);
940 struct spi_device
*spi
= priv
->spi
;
941 unsigned long flags
= IRQF_ONESHOT
| IRQF_TRIGGER_FALLING
;
944 ret
= open_candev(net
);
946 dev_err(&spi
->dev
, "unable to set initial baudrate!\n");
950 mutex_lock(&priv
->mcp_lock
);
951 mcp251x_power_enable(priv
->transceiver
, 1);
953 priv
->force_quit
= 0;
957 ret
= request_threaded_irq(spi
->irq
, NULL
, mcp251x_can_ist
,
958 flags
, DEVICE_NAME
, priv
);
960 dev_err(&spi
->dev
, "failed to acquire irq %d\n", spi
->irq
);
961 mcp251x_power_enable(priv
->transceiver
, 0);
966 priv
->wq
= create_freezable_workqueue("mcp251x_wq");
967 INIT_WORK(&priv
->tx_work
, mcp251x_tx_work_handler
);
968 INIT_WORK(&priv
->restart_work
, mcp251x_restart_work_handler
);
970 ret
= mcp251x_hw_reset(spi
);
972 mcp251x_open_clean(net
);
975 ret
= mcp251x_setup(net
, priv
, spi
);
977 mcp251x_open_clean(net
);
980 ret
= mcp251x_set_normal_mode(spi
);
982 mcp251x_open_clean(net
);
986 can_led_event(net
, CAN_LED_EVENT_OPEN
);
988 netif_wake_queue(net
);
991 mutex_unlock(&priv
->mcp_lock
);
995 static const struct net_device_ops mcp251x_netdev_ops
= {
996 .ndo_open
= mcp251x_open
,
997 .ndo_stop
= mcp251x_stop
,
998 .ndo_start_xmit
= mcp251x_hard_start_xmit
,
1001 static const struct of_device_id mcp251x_of_match
[] = {
1003 .compatible
= "microchip,mcp2510",
1004 .data
= (void *)CAN_MCP251X_MCP2510
,
1007 .compatible
= "microchip,mcp2515",
1008 .data
= (void *)CAN_MCP251X_MCP2515
,
1012 MODULE_DEVICE_TABLE(of
, mcp251x_of_match
);
1014 static const struct spi_device_id mcp251x_id_table
[] = {
1017 .driver_data
= (kernel_ulong_t
)CAN_MCP251X_MCP2510
,
1021 .driver_data
= (kernel_ulong_t
)CAN_MCP251X_MCP2515
,
1025 MODULE_DEVICE_TABLE(spi
, mcp251x_id_table
);
1027 static int mcp251x_can_probe(struct spi_device
*spi
)
1029 const struct of_device_id
*of_id
= of_match_device(mcp251x_of_match
,
1031 struct mcp251x_platform_data
*pdata
= dev_get_platdata(&spi
->dev
);
1032 struct net_device
*net
;
1033 struct mcp251x_priv
*priv
;
1034 int freq
, ret
= -ENODEV
;
1037 clk
= devm_clk_get(&spi
->dev
, NULL
);
1040 freq
= pdata
->oscillator_frequency
;
1042 return PTR_ERR(clk
);
1044 freq
= clk_get_rate(clk
);
1048 if (freq
< 1000000 || freq
> 25000000)
1051 /* Allocate can/net device */
1052 net
= alloc_candev(sizeof(struct mcp251x_priv
), TX_ECHO_SKB_MAX
);
1057 ret
= clk_prepare_enable(clk
);
1062 net
->netdev_ops
= &mcp251x_netdev_ops
;
1063 net
->flags
|= IFF_ECHO
;
1065 priv
= netdev_priv(net
);
1066 priv
->can
.bittiming_const
= &mcp251x_bittiming_const
;
1067 priv
->can
.do_set_mode
= mcp251x_do_set_mode
;
1068 priv
->can
.clock
.freq
= freq
/ 2;
1069 priv
->can
.ctrlmode_supported
= CAN_CTRLMODE_3_SAMPLES
|
1070 CAN_CTRLMODE_LOOPBACK
| CAN_CTRLMODE_LISTENONLY
;
1072 priv
->model
= (enum mcp251x_model
)of_id
->data
;
1074 priv
->model
= spi_get_device_id(spi
)->driver_data
;
1078 priv
->power
= devm_regulator_get(&spi
->dev
, "vdd");
1079 priv
->transceiver
= devm_regulator_get(&spi
->dev
, "xceiver");
1080 if ((PTR_ERR(priv
->power
) == -EPROBE_DEFER
) ||
1081 (PTR_ERR(priv
->transceiver
) == -EPROBE_DEFER
)) {
1082 ret
= -EPROBE_DEFER
;
1086 ret
= mcp251x_power_enable(priv
->power
, 1);
1090 spi_set_drvdata(spi
, priv
);
1093 mutex_init(&priv
->mcp_lock
);
1095 /* If requested, allocate DMA buffers */
1096 if (mcp251x_enable_dma
) {
1097 spi
->dev
.coherent_dma_mask
= ~0;
1100 * Minimum coherent DMA allocation is PAGE_SIZE, so allocate
1101 * that much and share it between Tx and Rx DMA buffers.
1103 priv
->spi_tx_buf
= dma_alloc_coherent(&spi
->dev
,
1108 if (priv
->spi_tx_buf
) {
1109 priv
->spi_rx_buf
= (priv
->spi_tx_buf
+ (PAGE_SIZE
/ 2));
1110 priv
->spi_rx_dma
= (dma_addr_t
)(priv
->spi_tx_dma
+
1113 /* Fall back to non-DMA */
1114 mcp251x_enable_dma
= 0;
1118 /* Allocate non-DMA buffers */
1119 if (!mcp251x_enable_dma
) {
1120 priv
->spi_tx_buf
= devm_kzalloc(&spi
->dev
, SPI_TRANSFER_BUF_LEN
,
1122 if (!priv
->spi_tx_buf
) {
1126 priv
->spi_rx_buf
= devm_kzalloc(&spi
->dev
, SPI_TRANSFER_BUF_LEN
,
1128 if (!priv
->spi_rx_buf
) {
1134 SET_NETDEV_DEV(net
, &spi
->dev
);
1136 /* Configure the SPI bus */
1137 spi
->mode
= spi
->mode
? : SPI_MODE_0
;
1138 if (mcp251x_is_2510(spi
))
1139 spi
->max_speed_hz
= spi
->max_speed_hz
? : 5 * 1000 * 1000;
1141 spi
->max_speed_hz
= spi
->max_speed_hz
? : 10 * 1000 * 1000;
1142 spi
->bits_per_word
= 8;
1145 /* Here is OK to not lock the MCP, no one knows about it yet */
1146 if (!mcp251x_hw_probe(spi
)) {
1150 mcp251x_hw_sleep(spi
);
1152 ret
= register_candev(net
);
1156 devm_can_led_init(net
);
1158 dev_info(&spi
->dev
, "probed\n");
1163 if (mcp251x_enable_dma
)
1164 dma_free_coherent(&spi
->dev
, PAGE_SIZE
,
1165 priv
->spi_tx_buf
, priv
->spi_tx_dma
);
1166 mcp251x_power_enable(priv
->power
, 0);
1170 clk_disable_unprepare(clk
);
1178 static int mcp251x_can_remove(struct spi_device
*spi
)
1180 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
1181 struct net_device
*net
= priv
->net
;
1183 unregister_candev(net
);
1185 if (mcp251x_enable_dma
) {
1186 dma_free_coherent(&spi
->dev
, PAGE_SIZE
,
1187 priv
->spi_tx_buf
, priv
->spi_tx_dma
);
1190 mcp251x_power_enable(priv
->power
, 0);
1192 if (!IS_ERR(priv
->clk
))
1193 clk_disable_unprepare(priv
->clk
);
1200 #ifdef CONFIG_PM_SLEEP
1202 static int mcp251x_can_suspend(struct device
*dev
)
1204 struct spi_device
*spi
= to_spi_device(dev
);
1205 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
1206 struct net_device
*net
= priv
->net
;
1208 priv
->force_quit
= 1;
1209 disable_irq(spi
->irq
);
1211 * Note: at this point neither IST nor workqueues are running.
1212 * open/stop cannot be called anyway so locking is not needed
1214 if (netif_running(net
)) {
1215 netif_device_detach(net
);
1217 mcp251x_hw_sleep(spi
);
1218 mcp251x_power_enable(priv
->transceiver
, 0);
1219 priv
->after_suspend
= AFTER_SUSPEND_UP
;
1221 priv
->after_suspend
= AFTER_SUSPEND_DOWN
;
1224 if (!IS_ERR(priv
->power
)) {
1225 regulator_disable(priv
->power
);
1226 priv
->after_suspend
|= AFTER_SUSPEND_POWER
;
1232 static int mcp251x_can_resume(struct device
*dev
)
1234 struct spi_device
*spi
= to_spi_device(dev
);
1235 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
1237 if (priv
->after_suspend
& AFTER_SUSPEND_POWER
) {
1238 mcp251x_power_enable(priv
->power
, 1);
1239 queue_work(priv
->wq
, &priv
->restart_work
);
1241 if (priv
->after_suspend
& AFTER_SUSPEND_UP
) {
1242 mcp251x_power_enable(priv
->transceiver
, 1);
1243 queue_work(priv
->wq
, &priv
->restart_work
);
1245 priv
->after_suspend
= 0;
1248 priv
->force_quit
= 0;
1249 enable_irq(spi
->irq
);
1254 static SIMPLE_DEV_PM_OPS(mcp251x_can_pm_ops
, mcp251x_can_suspend
,
1255 mcp251x_can_resume
);
1257 static struct spi_driver mcp251x_can_driver
= {
1259 .name
= DEVICE_NAME
,
1260 .owner
= THIS_MODULE
,
1261 .of_match_table
= mcp251x_of_match
,
1262 .pm
= &mcp251x_can_pm_ops
,
1264 .id_table
= mcp251x_id_table
,
1265 .probe
= mcp251x_can_probe
,
1266 .remove
= mcp251x_can_remove
,
1268 module_spi_driver(mcp251x_can_driver
);
1270 MODULE_AUTHOR("Chris Elston <celston@katalix.com>, "
1271 "Christian Pellegrin <chripell@evolware.org>");
1272 MODULE_DESCRIPTION("Microchip 251x CAN driver");
1273 MODULE_LICENSE("GPL v2");