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, write to the Free Software
32 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
36 * Your platform definition file should specify something like:
38 * static struct mcp251x_platform_data mcp251x_info = {
39 * .oscillator_frequency = 8000000,
40 * .board_specific_setup = &mcp251x_setup,
41 * .power_enable = mcp251x_power_enable,
42 * .transceiver_enable = NULL,
45 * static struct spi_board_info spi_board_info[] = {
47 * .modalias = "mcp2510",
48 * // or "mcp2515" depending on your controller
49 * .platform_data = &mcp251x_info,
51 * .max_speed_hz = 2*1000*1000,
56 * Please see mcp251x.h for a description of the fields in
57 * struct mcp251x_platform_data.
61 #include <linux/can/core.h>
62 #include <linux/can/dev.h>
63 #include <linux/can/led.h>
64 #include <linux/can/platform/mcp251x.h>
65 #include <linux/completion.h>
66 #include <linux/delay.h>
67 #include <linux/device.h>
68 #include <linux/dma-mapping.h>
69 #include <linux/freezer.h>
70 #include <linux/interrupt.h>
72 #include <linux/kernel.h>
73 #include <linux/module.h>
74 #include <linux/netdevice.h>
75 #include <linux/platform_device.h>
76 #include <linux/slab.h>
77 #include <linux/spi/spi.h>
78 #include <linux/uaccess.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
269 #define MCP251X_IS(_model) \
270 static inline int mcp251x_is_##_model(struct spi_device *spi) \
272 struct mcp251x_priv *priv = spi_get_drvdata(spi); \
273 return priv->model == CAN_MCP251X_MCP##_model; \
279 static void mcp251x_clean(struct net_device
*net
)
281 struct mcp251x_priv
*priv
= netdev_priv(net
);
283 if (priv
->tx_skb
|| priv
->tx_len
)
284 net
->stats
.tx_errors
++;
286 dev_kfree_skb(priv
->tx_skb
);
288 can_free_echo_skb(priv
->net
, 0);
294 * Note about handling of error return of mcp251x_spi_trans: accessing
295 * registers via SPI is not really different conceptually than using
296 * normal I/O assembler instructions, although it's much more
297 * complicated from a practical POV. So it's not advisable to always
298 * check the return value of this function. Imagine that every
299 * read{b,l}, write{b,l} and friends would be bracketed in "if ( < 0)
300 * error();", it would be a great mess (well there are some situation
301 * when exception handling C++ like could be useful after all). So we
302 * just check that transfers are OK at the beginning of our
303 * conversation with the chip and to avoid doing really nasty things
304 * (like injecting bogus packets in the network stack).
306 static int mcp251x_spi_trans(struct spi_device
*spi
, int len
)
308 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
309 struct spi_transfer t
= {
310 .tx_buf
= priv
->spi_tx_buf
,
311 .rx_buf
= priv
->spi_rx_buf
,
315 struct spi_message m
;
318 spi_message_init(&m
);
320 if (mcp251x_enable_dma
) {
321 t
.tx_dma
= priv
->spi_tx_dma
;
322 t
.rx_dma
= priv
->spi_rx_dma
;
326 spi_message_add_tail(&t
, &m
);
328 ret
= spi_sync(spi
, &m
);
330 dev_err(&spi
->dev
, "spi transfer failed: ret = %d\n", ret
);
334 static u8
mcp251x_read_reg(struct spi_device
*spi
, uint8_t reg
)
336 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
339 priv
->spi_tx_buf
[0] = INSTRUCTION_READ
;
340 priv
->spi_tx_buf
[1] = reg
;
342 mcp251x_spi_trans(spi
, 3);
343 val
= priv
->spi_rx_buf
[2];
348 static void mcp251x_read_2regs(struct spi_device
*spi
, uint8_t reg
,
349 uint8_t *v1
, uint8_t *v2
)
351 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
353 priv
->spi_tx_buf
[0] = INSTRUCTION_READ
;
354 priv
->spi_tx_buf
[1] = reg
;
356 mcp251x_spi_trans(spi
, 4);
358 *v1
= priv
->spi_rx_buf
[2];
359 *v2
= priv
->spi_rx_buf
[3];
362 static void mcp251x_write_reg(struct spi_device
*spi
, u8 reg
, uint8_t val
)
364 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
366 priv
->spi_tx_buf
[0] = INSTRUCTION_WRITE
;
367 priv
->spi_tx_buf
[1] = reg
;
368 priv
->spi_tx_buf
[2] = val
;
370 mcp251x_spi_trans(spi
, 3);
373 static void mcp251x_write_bits(struct spi_device
*spi
, u8 reg
,
374 u8 mask
, uint8_t val
)
376 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
378 priv
->spi_tx_buf
[0] = INSTRUCTION_BIT_MODIFY
;
379 priv
->spi_tx_buf
[1] = reg
;
380 priv
->spi_tx_buf
[2] = mask
;
381 priv
->spi_tx_buf
[3] = val
;
383 mcp251x_spi_trans(spi
, 4);
386 static void mcp251x_hw_tx_frame(struct spi_device
*spi
, u8
*buf
,
387 int len
, int tx_buf_idx
)
389 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
391 if (mcp251x_is_2510(spi
)) {
394 for (i
= 1; i
< TXBDAT_OFF
+ len
; i
++)
395 mcp251x_write_reg(spi
, TXBCTRL(tx_buf_idx
) + i
,
398 memcpy(priv
->spi_tx_buf
, buf
, TXBDAT_OFF
+ len
);
399 mcp251x_spi_trans(spi
, TXBDAT_OFF
+ len
);
403 static void mcp251x_hw_tx(struct spi_device
*spi
, struct can_frame
*frame
,
406 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
407 u32 sid
, eid
, exide
, rtr
;
408 u8 buf
[SPI_TRANSFER_BUF_LEN
];
410 exide
= (frame
->can_id
& CAN_EFF_FLAG
) ? 1 : 0; /* Extended ID Enable */
412 sid
= (frame
->can_id
& CAN_EFF_MASK
) >> 18;
414 sid
= frame
->can_id
& CAN_SFF_MASK
; /* Standard ID */
415 eid
= frame
->can_id
& CAN_EFF_MASK
; /* Extended ID */
416 rtr
= (frame
->can_id
& CAN_RTR_FLAG
) ? 1 : 0; /* Remote transmission */
418 buf
[TXBCTRL_OFF
] = INSTRUCTION_LOAD_TXB(tx_buf_idx
);
419 buf
[TXBSIDH_OFF
] = sid
>> SIDH_SHIFT
;
420 buf
[TXBSIDL_OFF
] = ((sid
& SIDL_SID_MASK
) << SIDL_SID_SHIFT
) |
421 (exide
<< SIDL_EXIDE_SHIFT
) |
422 ((eid
>> SIDL_EID_SHIFT
) & SIDL_EID_MASK
);
423 buf
[TXBEID8_OFF
] = GET_BYTE(eid
, 1);
424 buf
[TXBEID0_OFF
] = GET_BYTE(eid
, 0);
425 buf
[TXBDLC_OFF
] = (rtr
<< DLC_RTR_SHIFT
) | frame
->can_dlc
;
426 memcpy(buf
+ TXBDAT_OFF
, frame
->data
, frame
->can_dlc
);
427 mcp251x_hw_tx_frame(spi
, buf
, frame
->can_dlc
, tx_buf_idx
);
429 /* use INSTRUCTION_RTS, to avoid "repeated frame problem" */
430 priv
->spi_tx_buf
[0] = INSTRUCTION_RTS(1 << tx_buf_idx
);
431 mcp251x_spi_trans(priv
->spi
, 1);
434 static void mcp251x_hw_rx_frame(struct spi_device
*spi
, u8
*buf
,
437 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
439 if (mcp251x_is_2510(spi
)) {
442 for (i
= 1; i
< RXBDAT_OFF
; i
++)
443 buf
[i
] = mcp251x_read_reg(spi
, RXBCTRL(buf_idx
) + i
);
445 len
= get_can_dlc(buf
[RXBDLC_OFF
] & RXBDLC_LEN_MASK
);
446 for (; i
< (RXBDAT_OFF
+ len
); i
++)
447 buf
[i
] = mcp251x_read_reg(spi
, RXBCTRL(buf_idx
) + i
);
449 priv
->spi_tx_buf
[RXBCTRL_OFF
] = INSTRUCTION_READ_RXB(buf_idx
);
450 mcp251x_spi_trans(spi
, SPI_TRANSFER_BUF_LEN
);
451 memcpy(buf
, priv
->spi_rx_buf
, SPI_TRANSFER_BUF_LEN
);
455 static void mcp251x_hw_rx(struct spi_device
*spi
, int buf_idx
)
457 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
459 struct can_frame
*frame
;
460 u8 buf
[SPI_TRANSFER_BUF_LEN
];
462 skb
= alloc_can_skb(priv
->net
, &frame
);
464 dev_err(&spi
->dev
, "cannot allocate RX skb\n");
465 priv
->net
->stats
.rx_dropped
++;
469 mcp251x_hw_rx_frame(spi
, buf
, buf_idx
);
470 if (buf
[RXBSIDL_OFF
] & RXBSIDL_IDE
) {
471 /* Extended ID format */
472 frame
->can_id
= CAN_EFF_FLAG
;
474 /* Extended ID part */
475 SET_BYTE(buf
[RXBSIDL_OFF
] & RXBSIDL_EID
, 2) |
476 SET_BYTE(buf
[RXBEID8_OFF
], 1) |
477 SET_BYTE(buf
[RXBEID0_OFF
], 0) |
478 /* Standard ID part */
479 (((buf
[RXBSIDH_OFF
] << RXBSIDH_SHIFT
) |
480 (buf
[RXBSIDL_OFF
] >> RXBSIDL_SHIFT
)) << 18);
481 /* Remote transmission request */
482 if (buf
[RXBDLC_OFF
] & RXBDLC_RTR
)
483 frame
->can_id
|= CAN_RTR_FLAG
;
485 /* Standard ID format */
487 (buf
[RXBSIDH_OFF
] << RXBSIDH_SHIFT
) |
488 (buf
[RXBSIDL_OFF
] >> RXBSIDL_SHIFT
);
489 if (buf
[RXBSIDL_OFF
] & RXBSIDL_SRR
)
490 frame
->can_id
|= CAN_RTR_FLAG
;
493 frame
->can_dlc
= get_can_dlc(buf
[RXBDLC_OFF
] & RXBDLC_LEN_MASK
);
494 memcpy(frame
->data
, buf
+ RXBDAT_OFF
, frame
->can_dlc
);
496 priv
->net
->stats
.rx_packets
++;
497 priv
->net
->stats
.rx_bytes
+= frame
->can_dlc
;
499 can_led_event(priv
->net
, CAN_LED_EVENT_RX
);
504 static void mcp251x_hw_sleep(struct spi_device
*spi
)
506 mcp251x_write_reg(spi
, CANCTRL
, CANCTRL_REQOP_SLEEP
);
509 static netdev_tx_t
mcp251x_hard_start_xmit(struct sk_buff
*skb
,
510 struct net_device
*net
)
512 struct mcp251x_priv
*priv
= netdev_priv(net
);
513 struct spi_device
*spi
= priv
->spi
;
515 if (priv
->tx_skb
|| priv
->tx_len
) {
516 dev_warn(&spi
->dev
, "hard_xmit called while tx busy\n");
517 return NETDEV_TX_BUSY
;
520 if (can_dropped_invalid_skb(net
, skb
))
523 netif_stop_queue(net
);
525 queue_work(priv
->wq
, &priv
->tx_work
);
530 static int mcp251x_do_set_mode(struct net_device
*net
, enum can_mode mode
)
532 struct mcp251x_priv
*priv
= netdev_priv(net
);
537 /* We have to delay work since SPI I/O may sleep */
538 priv
->can
.state
= CAN_STATE_ERROR_ACTIVE
;
539 priv
->restart_tx
= 1;
540 if (priv
->can
.restart_ms
== 0)
541 priv
->after_suspend
= AFTER_SUSPEND_RESTART
;
542 queue_work(priv
->wq
, &priv
->restart_work
);
551 static int mcp251x_set_normal_mode(struct spi_device
*spi
)
553 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
554 unsigned long timeout
;
556 /* Enable interrupts */
557 mcp251x_write_reg(spi
, CANINTE
,
558 CANINTE_ERRIE
| CANINTE_TX2IE
| CANINTE_TX1IE
|
559 CANINTE_TX0IE
| CANINTE_RX1IE
| CANINTE_RX0IE
);
561 if (priv
->can
.ctrlmode
& CAN_CTRLMODE_LOOPBACK
) {
562 /* Put device into loopback mode */
563 mcp251x_write_reg(spi
, CANCTRL
, CANCTRL_REQOP_LOOPBACK
);
564 } else if (priv
->can
.ctrlmode
& CAN_CTRLMODE_LISTENONLY
) {
565 /* Put device into listen-only mode */
566 mcp251x_write_reg(spi
, CANCTRL
, CANCTRL_REQOP_LISTEN_ONLY
);
568 /* Put device into normal mode */
569 mcp251x_write_reg(spi
, CANCTRL
, CANCTRL_REQOP_NORMAL
);
571 /* Wait for the device to enter normal mode */
572 timeout
= jiffies
+ HZ
;
573 while (mcp251x_read_reg(spi
, CANSTAT
) & CANCTRL_REQOP_MASK
) {
575 if (time_after(jiffies
, timeout
)) {
576 dev_err(&spi
->dev
, "MCP251x didn't"
577 " enter in normal mode\n");
582 priv
->can
.state
= CAN_STATE_ERROR_ACTIVE
;
586 static int mcp251x_do_set_bittiming(struct net_device
*net
)
588 struct mcp251x_priv
*priv
= netdev_priv(net
);
589 struct can_bittiming
*bt
= &priv
->can
.bittiming
;
590 struct spi_device
*spi
= priv
->spi
;
592 mcp251x_write_reg(spi
, CNF1
, ((bt
->sjw
- 1) << CNF1_SJW_SHIFT
) |
594 mcp251x_write_reg(spi
, CNF2
, CNF2_BTLMODE
|
595 (priv
->can
.ctrlmode
& CAN_CTRLMODE_3_SAMPLES
?
597 ((bt
->phase_seg1
- 1) << CNF2_PS1_SHIFT
) |
599 mcp251x_write_bits(spi
, CNF3
, CNF3_PHSEG2_MASK
,
600 (bt
->phase_seg2
- 1));
601 dev_info(&spi
->dev
, "CNF: 0x%02x 0x%02x 0x%02x\n",
602 mcp251x_read_reg(spi
, CNF1
),
603 mcp251x_read_reg(spi
, CNF2
),
604 mcp251x_read_reg(spi
, CNF3
));
609 static int mcp251x_setup(struct net_device
*net
, struct mcp251x_priv
*priv
,
610 struct spi_device
*spi
)
612 mcp251x_do_set_bittiming(net
);
614 mcp251x_write_reg(spi
, RXBCTRL(0),
615 RXBCTRL_BUKT
| RXBCTRL_RXM0
| RXBCTRL_RXM1
);
616 mcp251x_write_reg(spi
, RXBCTRL(1),
617 RXBCTRL_RXM0
| RXBCTRL_RXM1
);
621 static int mcp251x_hw_reset(struct spi_device
*spi
)
623 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
625 unsigned long timeout
;
627 priv
->spi_tx_buf
[0] = INSTRUCTION_RESET
;
628 ret
= spi_write(spi
, priv
->spi_tx_buf
, 1);
630 dev_err(&spi
->dev
, "reset failed: ret = %d\n", ret
);
634 /* Wait for reset to finish */
635 timeout
= jiffies
+ HZ
;
637 while ((mcp251x_read_reg(spi
, CANSTAT
) & CANCTRL_REQOP_MASK
)
638 != CANCTRL_REQOP_CONF
) {
640 if (time_after(jiffies
, timeout
)) {
641 dev_err(&spi
->dev
, "MCP251x didn't"
642 " enter in conf mode after reset\n");
649 static int mcp251x_hw_probe(struct spi_device
*spi
)
653 mcp251x_hw_reset(spi
);
656 * Please note that these are "magic values" based on after
657 * reset defaults taken from data sheet which allows us to see
658 * if we really have a chip on the bus (we avoid common all
659 * zeroes or all ones situations)
661 st1
= mcp251x_read_reg(spi
, CANSTAT
) & 0xEE;
662 st2
= mcp251x_read_reg(spi
, CANCTRL
) & 0x17;
664 dev_dbg(&spi
->dev
, "CANSTAT 0x%02x CANCTRL 0x%02x\n", st1
, st2
);
666 /* Check for power up default values */
667 return (st1
== 0x80 && st2
== 0x07) ? 1 : 0;
670 static void mcp251x_open_clean(struct net_device
*net
)
672 struct mcp251x_priv
*priv
= netdev_priv(net
);
673 struct spi_device
*spi
= priv
->spi
;
674 struct mcp251x_platform_data
*pdata
= spi
->dev
.platform_data
;
676 free_irq(spi
->irq
, priv
);
677 mcp251x_hw_sleep(spi
);
678 if (pdata
->transceiver_enable
)
679 pdata
->transceiver_enable(0);
683 static int mcp251x_stop(struct net_device
*net
)
685 struct mcp251x_priv
*priv
= netdev_priv(net
);
686 struct spi_device
*spi
= priv
->spi
;
687 struct mcp251x_platform_data
*pdata
= spi
->dev
.platform_data
;
691 priv
->force_quit
= 1;
692 free_irq(spi
->irq
, priv
);
693 destroy_workqueue(priv
->wq
);
696 mutex_lock(&priv
->mcp_lock
);
698 /* Disable and clear pending interrupts */
699 mcp251x_write_reg(spi
, CANINTE
, 0x00);
700 mcp251x_write_reg(spi
, CANINTF
, 0x00);
702 mcp251x_write_reg(spi
, TXBCTRL(0), 0);
705 mcp251x_hw_sleep(spi
);
707 if (pdata
->transceiver_enable
)
708 pdata
->transceiver_enable(0);
710 priv
->can
.state
= CAN_STATE_STOPPED
;
712 mutex_unlock(&priv
->mcp_lock
);
714 can_led_event(net
, CAN_LED_EVENT_STOP
);
719 static void mcp251x_error_skb(struct net_device
*net
, int can_id
, int data1
)
722 struct can_frame
*frame
;
724 skb
= alloc_can_err_skb(net
, &frame
);
726 frame
->can_id
|= can_id
;
727 frame
->data
[1] = data1
;
730 netdev_err(net
, "cannot allocate error skb\n");
734 static void mcp251x_tx_work_handler(struct work_struct
*ws
)
736 struct mcp251x_priv
*priv
= container_of(ws
, struct mcp251x_priv
,
738 struct spi_device
*spi
= priv
->spi
;
739 struct net_device
*net
= priv
->net
;
740 struct can_frame
*frame
;
742 mutex_lock(&priv
->mcp_lock
);
744 if (priv
->can
.state
== CAN_STATE_BUS_OFF
) {
747 frame
= (struct can_frame
*)priv
->tx_skb
->data
;
749 if (frame
->can_dlc
> CAN_FRAME_MAX_DATA_LEN
)
750 frame
->can_dlc
= CAN_FRAME_MAX_DATA_LEN
;
751 mcp251x_hw_tx(spi
, frame
, 0);
752 priv
->tx_len
= 1 + frame
->can_dlc
;
753 can_put_echo_skb(priv
->tx_skb
, net
, 0);
757 mutex_unlock(&priv
->mcp_lock
);
760 static void mcp251x_restart_work_handler(struct work_struct
*ws
)
762 struct mcp251x_priv
*priv
= container_of(ws
, struct mcp251x_priv
,
764 struct spi_device
*spi
= priv
->spi
;
765 struct net_device
*net
= priv
->net
;
767 mutex_lock(&priv
->mcp_lock
);
768 if (priv
->after_suspend
) {
770 mcp251x_hw_reset(spi
);
771 mcp251x_setup(net
, priv
, spi
);
772 if (priv
->after_suspend
& AFTER_SUSPEND_RESTART
) {
773 mcp251x_set_normal_mode(spi
);
774 } else if (priv
->after_suspend
& AFTER_SUSPEND_UP
) {
775 netif_device_attach(net
);
777 mcp251x_set_normal_mode(spi
);
778 netif_wake_queue(net
);
780 mcp251x_hw_sleep(spi
);
782 priv
->after_suspend
= 0;
783 priv
->force_quit
= 0;
786 if (priv
->restart_tx
) {
787 priv
->restart_tx
= 0;
788 mcp251x_write_reg(spi
, TXBCTRL(0), 0);
790 netif_wake_queue(net
);
791 mcp251x_error_skb(net
, CAN_ERR_RESTARTED
, 0);
793 mutex_unlock(&priv
->mcp_lock
);
796 static irqreturn_t
mcp251x_can_ist(int irq
, void *dev_id
)
798 struct mcp251x_priv
*priv
= dev_id
;
799 struct spi_device
*spi
= priv
->spi
;
800 struct net_device
*net
= priv
->net
;
802 mutex_lock(&priv
->mcp_lock
);
803 while (!priv
->force_quit
) {
804 enum can_state new_state
;
807 int can_id
= 0, data1
= 0;
809 mcp251x_read_2regs(spi
, CANINTF
, &intf
, &eflag
);
811 /* mask out flags we don't care about */
812 intf
&= CANINTF_RX
| CANINTF_TX
| CANINTF_ERR
;
814 /* receive buffer 0 */
815 if (intf
& CANINTF_RX0IF
) {
816 mcp251x_hw_rx(spi
, 0);
818 * Free one buffer ASAP
819 * (The MCP2515 does this automatically.)
821 if (mcp251x_is_2510(spi
))
822 mcp251x_write_bits(spi
, CANINTF
, CANINTF_RX0IF
, 0x00);
825 /* receive buffer 1 */
826 if (intf
& CANINTF_RX1IF
) {
827 mcp251x_hw_rx(spi
, 1);
828 /* the MCP2515 does this automatically */
829 if (mcp251x_is_2510(spi
))
830 clear_intf
|= CANINTF_RX1IF
;
833 /* any error or tx interrupt we need to clear? */
834 if (intf
& (CANINTF_ERR
| CANINTF_TX
))
835 clear_intf
|= intf
& (CANINTF_ERR
| CANINTF_TX
);
837 mcp251x_write_bits(spi
, CANINTF
, clear_intf
, 0x00);
840 mcp251x_write_bits(spi
, EFLG
, eflag
, 0x00);
842 /* Update can state */
843 if (eflag
& EFLG_TXBO
) {
844 new_state
= CAN_STATE_BUS_OFF
;
845 can_id
|= CAN_ERR_BUSOFF
;
846 } else if (eflag
& EFLG_TXEP
) {
847 new_state
= CAN_STATE_ERROR_PASSIVE
;
848 can_id
|= CAN_ERR_CRTL
;
849 data1
|= CAN_ERR_CRTL_TX_PASSIVE
;
850 } else if (eflag
& EFLG_RXEP
) {
851 new_state
= CAN_STATE_ERROR_PASSIVE
;
852 can_id
|= CAN_ERR_CRTL
;
853 data1
|= CAN_ERR_CRTL_RX_PASSIVE
;
854 } else if (eflag
& EFLG_TXWAR
) {
855 new_state
= CAN_STATE_ERROR_WARNING
;
856 can_id
|= CAN_ERR_CRTL
;
857 data1
|= CAN_ERR_CRTL_TX_WARNING
;
858 } else if (eflag
& EFLG_RXWAR
) {
859 new_state
= CAN_STATE_ERROR_WARNING
;
860 can_id
|= CAN_ERR_CRTL
;
861 data1
|= CAN_ERR_CRTL_RX_WARNING
;
863 new_state
= CAN_STATE_ERROR_ACTIVE
;
866 /* Update can state statistics */
867 switch (priv
->can
.state
) {
868 case CAN_STATE_ERROR_ACTIVE
:
869 if (new_state
>= CAN_STATE_ERROR_WARNING
&&
870 new_state
<= CAN_STATE_BUS_OFF
)
871 priv
->can
.can_stats
.error_warning
++;
872 case CAN_STATE_ERROR_WARNING
: /* fallthrough */
873 if (new_state
>= CAN_STATE_ERROR_PASSIVE
&&
874 new_state
<= CAN_STATE_BUS_OFF
)
875 priv
->can
.can_stats
.error_passive
++;
880 priv
->can
.state
= new_state
;
882 if (intf
& CANINTF_ERRIF
) {
883 /* Handle overflow counters */
884 if (eflag
& (EFLG_RX0OVR
| EFLG_RX1OVR
)) {
885 if (eflag
& EFLG_RX0OVR
) {
886 net
->stats
.rx_over_errors
++;
887 net
->stats
.rx_errors
++;
889 if (eflag
& EFLG_RX1OVR
) {
890 net
->stats
.rx_over_errors
++;
891 net
->stats
.rx_errors
++;
893 can_id
|= CAN_ERR_CRTL
;
894 data1
|= CAN_ERR_CRTL_RX_OVERFLOW
;
896 mcp251x_error_skb(net
, can_id
, data1
);
899 if (priv
->can
.state
== CAN_STATE_BUS_OFF
) {
900 if (priv
->can
.restart_ms
== 0) {
901 priv
->force_quit
= 1;
903 mcp251x_hw_sleep(spi
);
911 if (intf
& CANINTF_TX
) {
912 net
->stats
.tx_packets
++;
913 net
->stats
.tx_bytes
+= priv
->tx_len
- 1;
914 can_led_event(net
, CAN_LED_EVENT_TX
);
916 can_get_echo_skb(net
, 0);
919 netif_wake_queue(net
);
923 mutex_unlock(&priv
->mcp_lock
);
927 static int mcp251x_open(struct net_device
*net
)
929 struct mcp251x_priv
*priv
= netdev_priv(net
);
930 struct spi_device
*spi
= priv
->spi
;
931 struct mcp251x_platform_data
*pdata
= spi
->dev
.platform_data
;
935 ret
= open_candev(net
);
937 dev_err(&spi
->dev
, "unable to set initial baudrate!\n");
941 mutex_lock(&priv
->mcp_lock
);
942 if (pdata
->transceiver_enable
)
943 pdata
->transceiver_enable(1);
945 priv
->force_quit
= 0;
949 flags
= IRQF_ONESHOT
;
950 if (pdata
->irq_flags
)
951 flags
|= pdata
->irq_flags
;
953 flags
|= IRQF_TRIGGER_FALLING
;
955 ret
= request_threaded_irq(spi
->irq
, NULL
, mcp251x_can_ist
,
956 flags
, DEVICE_NAME
, priv
);
958 dev_err(&spi
->dev
, "failed to acquire irq %d\n", spi
->irq
);
959 if (pdata
->transceiver_enable
)
960 pdata
->transceiver_enable(0);
965 priv
->wq
= create_freezable_workqueue("mcp251x_wq");
966 INIT_WORK(&priv
->tx_work
, mcp251x_tx_work_handler
);
967 INIT_WORK(&priv
->restart_work
, mcp251x_restart_work_handler
);
969 ret
= mcp251x_hw_reset(spi
);
971 mcp251x_open_clean(net
);
974 ret
= mcp251x_setup(net
, priv
, spi
);
976 mcp251x_open_clean(net
);
979 ret
= mcp251x_set_normal_mode(spi
);
981 mcp251x_open_clean(net
);
985 can_led_event(net
, CAN_LED_EVENT_OPEN
);
987 netif_wake_queue(net
);
990 mutex_unlock(&priv
->mcp_lock
);
994 static const struct net_device_ops mcp251x_netdev_ops
= {
995 .ndo_open
= mcp251x_open
,
996 .ndo_stop
= mcp251x_stop
,
997 .ndo_start_xmit
= mcp251x_hard_start_xmit
,
1000 static int mcp251x_can_probe(struct spi_device
*spi
)
1002 struct net_device
*net
;
1003 struct mcp251x_priv
*priv
;
1004 struct mcp251x_platform_data
*pdata
= spi
->dev
.platform_data
;
1008 /* Platform data is required for osc freq */
1011 /* Allocate can/net device */
1012 net
= alloc_candev(sizeof(struct mcp251x_priv
), TX_ECHO_SKB_MAX
);
1018 net
->netdev_ops
= &mcp251x_netdev_ops
;
1019 net
->flags
|= IFF_ECHO
;
1021 priv
= netdev_priv(net
);
1022 priv
->can
.bittiming_const
= &mcp251x_bittiming_const
;
1023 priv
->can
.do_set_mode
= mcp251x_do_set_mode
;
1024 priv
->can
.clock
.freq
= pdata
->oscillator_frequency
/ 2;
1025 priv
->can
.ctrlmode_supported
= CAN_CTRLMODE_3_SAMPLES
|
1026 CAN_CTRLMODE_LOOPBACK
| CAN_CTRLMODE_LISTENONLY
;
1027 priv
->model
= spi_get_device_id(spi
)->driver_data
;
1029 spi_set_drvdata(spi
, priv
);
1032 mutex_init(&priv
->mcp_lock
);
1034 /* If requested, allocate DMA buffers */
1035 if (mcp251x_enable_dma
) {
1036 spi
->dev
.coherent_dma_mask
= ~0;
1039 * Minimum coherent DMA allocation is PAGE_SIZE, so allocate
1040 * that much and share it between Tx and Rx DMA buffers.
1042 priv
->spi_tx_buf
= dma_alloc_coherent(&spi
->dev
,
1047 if (priv
->spi_tx_buf
) {
1048 priv
->spi_rx_buf
= (priv
->spi_tx_buf
+ (PAGE_SIZE
/ 2));
1049 priv
->spi_rx_dma
= (dma_addr_t
)(priv
->spi_tx_dma
+
1052 /* Fall back to non-DMA */
1053 mcp251x_enable_dma
= 0;
1057 /* Allocate non-DMA buffers */
1058 if (!mcp251x_enable_dma
) {
1059 priv
->spi_tx_buf
= kmalloc(SPI_TRANSFER_BUF_LEN
, GFP_KERNEL
);
1060 if (!priv
->spi_tx_buf
) {
1064 priv
->spi_rx_buf
= kmalloc(SPI_TRANSFER_BUF_LEN
, GFP_KERNEL
);
1065 if (!priv
->spi_rx_buf
) {
1071 if (pdata
->power_enable
)
1072 pdata
->power_enable(1);
1074 /* Call out to platform specific setup */
1075 if (pdata
->board_specific_setup
)
1076 pdata
->board_specific_setup(spi
);
1078 SET_NETDEV_DEV(net
, &spi
->dev
);
1080 /* Configure the SPI bus */
1081 spi
->mode
= SPI_MODE_0
;
1082 spi
->bits_per_word
= 8;
1085 /* Here is OK to not lock the MCP, no one knows about it yet */
1086 if (!mcp251x_hw_probe(spi
)) {
1087 dev_info(&spi
->dev
, "Probe failed\n");
1090 mcp251x_hw_sleep(spi
);
1092 if (pdata
->transceiver_enable
)
1093 pdata
->transceiver_enable(0);
1095 ret
= register_candev(net
);
1099 devm_can_led_init(net
);
1101 dev_info(&spi
->dev
, "probed\n");
1106 if (!mcp251x_enable_dma
)
1107 kfree(priv
->spi_rx_buf
);
1109 if (!mcp251x_enable_dma
)
1110 kfree(priv
->spi_tx_buf
);
1113 if (mcp251x_enable_dma
)
1114 dma_free_coherent(&spi
->dev
, PAGE_SIZE
,
1115 priv
->spi_tx_buf
, priv
->spi_tx_dma
);
1117 if (pdata
->power_enable
)
1118 pdata
->power_enable(0);
1119 dev_err(&spi
->dev
, "probe failed\n");
1124 static int mcp251x_can_remove(struct spi_device
*spi
)
1126 struct mcp251x_platform_data
*pdata
= spi
->dev
.platform_data
;
1127 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
1128 struct net_device
*net
= priv
->net
;
1130 unregister_candev(net
);
1133 if (mcp251x_enable_dma
) {
1134 dma_free_coherent(&spi
->dev
, PAGE_SIZE
,
1135 priv
->spi_tx_buf
, priv
->spi_tx_dma
);
1137 kfree(priv
->spi_tx_buf
);
1138 kfree(priv
->spi_rx_buf
);
1141 if (pdata
->power_enable
)
1142 pdata
->power_enable(0);
1147 #ifdef CONFIG_PM_SLEEP
1149 static int mcp251x_can_suspend(struct device
*dev
)
1151 struct spi_device
*spi
= to_spi_device(dev
);
1152 struct mcp251x_platform_data
*pdata
= spi
->dev
.platform_data
;
1153 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
1154 struct net_device
*net
= priv
->net
;
1156 priv
->force_quit
= 1;
1157 disable_irq(spi
->irq
);
1159 * Note: at this point neither IST nor workqueues are running.
1160 * open/stop cannot be called anyway so locking is not needed
1162 if (netif_running(net
)) {
1163 netif_device_detach(net
);
1165 mcp251x_hw_sleep(spi
);
1166 if (pdata
->transceiver_enable
)
1167 pdata
->transceiver_enable(0);
1168 priv
->after_suspend
= AFTER_SUSPEND_UP
;
1170 priv
->after_suspend
= AFTER_SUSPEND_DOWN
;
1173 if (pdata
->power_enable
) {
1174 pdata
->power_enable(0);
1175 priv
->after_suspend
|= AFTER_SUSPEND_POWER
;
1181 static int mcp251x_can_resume(struct device
*dev
)
1183 struct spi_device
*spi
= to_spi_device(dev
);
1184 struct mcp251x_platform_data
*pdata
= spi
->dev
.platform_data
;
1185 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
1187 if (priv
->after_suspend
& AFTER_SUSPEND_POWER
) {
1188 pdata
->power_enable(1);
1189 queue_work(priv
->wq
, &priv
->restart_work
);
1191 if (priv
->after_suspend
& AFTER_SUSPEND_UP
) {
1192 if (pdata
->transceiver_enable
)
1193 pdata
->transceiver_enable(1);
1194 queue_work(priv
->wq
, &priv
->restart_work
);
1196 priv
->after_suspend
= 0;
1199 priv
->force_quit
= 0;
1200 enable_irq(spi
->irq
);
1205 static SIMPLE_DEV_PM_OPS(mcp251x_can_pm_ops
, mcp251x_can_suspend
,
1206 mcp251x_can_resume
);
1208 static const struct spi_device_id mcp251x_id_table
[] = {
1209 { "mcp2510", CAN_MCP251X_MCP2510
},
1210 { "mcp2515", CAN_MCP251X_MCP2515
},
1214 MODULE_DEVICE_TABLE(spi
, mcp251x_id_table
);
1216 static struct spi_driver mcp251x_can_driver
= {
1218 .name
= DEVICE_NAME
,
1219 .owner
= THIS_MODULE
,
1220 .pm
= &mcp251x_can_pm_ops
,
1223 .id_table
= mcp251x_id_table
,
1224 .probe
= mcp251x_can_probe
,
1225 .remove
= mcp251x_can_remove
,
1227 module_spi_driver(mcp251x_can_driver
);
1229 MODULE_AUTHOR("Chris Elston <celston@katalix.com>, "
1230 "Christian Pellegrin <chripell@evolware.org>");
1231 MODULE_DESCRIPTION("Microchip 251x CAN driver");
1232 MODULE_LICENSE("GPL v2");