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 MCP251X_OST_DELAY_MS (5)
219 #define DEVICE_NAME "mcp251x"
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)");
225 static const struct can_bittiming_const mcp251x_bittiming_const
= {
238 CAN_MCP251X_MCP2510
= 0x2510,
239 CAN_MCP251X_MCP2515
= 0x2515,
242 struct mcp251x_priv
{
244 struct net_device
*net
;
245 struct spi_device
*spi
;
246 enum mcp251x_model model
;
248 struct mutex mcp_lock
; /* SPI device lock */
252 dma_addr_t spi_tx_dma
;
253 dma_addr_t spi_rx_dma
;
255 struct sk_buff
*tx_skb
;
258 struct workqueue_struct
*wq
;
259 struct work_struct tx_work
;
260 struct work_struct restart_work
;
264 #define AFTER_SUSPEND_UP 1
265 #define AFTER_SUSPEND_DOWN 2
266 #define AFTER_SUSPEND_POWER 4
267 #define AFTER_SUSPEND_RESTART 8
269 struct regulator
*power
;
270 struct regulator
*transceiver
;
274 #define MCP251X_IS(_model) \
275 static inline int mcp251x_is_##_model(struct spi_device *spi) \
277 struct mcp251x_priv *priv = spi_get_drvdata(spi); \
278 return priv->model == CAN_MCP251X_MCP##_model; \
284 static void mcp251x_clean(struct net_device
*net
)
286 struct mcp251x_priv
*priv
= netdev_priv(net
);
288 if (priv
->tx_skb
|| priv
->tx_len
)
289 net
->stats
.tx_errors
++;
291 dev_kfree_skb(priv
->tx_skb
);
293 can_free_echo_skb(priv
->net
, 0);
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).
311 static int mcp251x_spi_trans(struct spi_device
*spi
, int len
)
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
,
320 struct spi_message m
;
323 spi_message_init(&m
);
325 if (mcp251x_enable_dma
) {
326 t
.tx_dma
= priv
->spi_tx_dma
;
327 t
.rx_dma
= priv
->spi_rx_dma
;
331 spi_message_add_tail(&t
, &m
);
333 ret
= spi_sync(spi
, &m
);
335 dev_err(&spi
->dev
, "spi transfer failed: ret = %d\n", ret
);
339 static u8
mcp251x_read_reg(struct spi_device
*spi
, uint8_t reg
)
341 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
344 priv
->spi_tx_buf
[0] = INSTRUCTION_READ
;
345 priv
->spi_tx_buf
[1] = reg
;
347 mcp251x_spi_trans(spi
, 3);
348 val
= priv
->spi_rx_buf
[2];
353 static void mcp251x_read_2regs(struct spi_device
*spi
, uint8_t reg
,
354 uint8_t *v1
, uint8_t *v2
)
356 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
358 priv
->spi_tx_buf
[0] = INSTRUCTION_READ
;
359 priv
->spi_tx_buf
[1] = reg
;
361 mcp251x_spi_trans(spi
, 4);
363 *v1
= priv
->spi_rx_buf
[2];
364 *v2
= priv
->spi_rx_buf
[3];
367 static void mcp251x_write_reg(struct spi_device
*spi
, u8 reg
, uint8_t val
)
369 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
371 priv
->spi_tx_buf
[0] = INSTRUCTION_WRITE
;
372 priv
->spi_tx_buf
[1] = reg
;
373 priv
->spi_tx_buf
[2] = val
;
375 mcp251x_spi_trans(spi
, 3);
378 static void mcp251x_write_bits(struct spi_device
*spi
, u8 reg
,
379 u8 mask
, uint8_t val
)
381 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
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
;
388 mcp251x_spi_trans(spi
, 4);
391 static void mcp251x_hw_tx_frame(struct spi_device
*spi
, u8
*buf
,
392 int len
, int tx_buf_idx
)
394 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
396 if (mcp251x_is_2510(spi
)) {
399 for (i
= 1; i
< TXBDAT_OFF
+ len
; i
++)
400 mcp251x_write_reg(spi
, TXBCTRL(tx_buf_idx
) + i
,
403 memcpy(priv
->spi_tx_buf
, buf
, TXBDAT_OFF
+ len
);
404 mcp251x_spi_trans(spi
, TXBDAT_OFF
+ len
);
408 static void mcp251x_hw_tx(struct spi_device
*spi
, struct can_frame
*frame
,
411 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
412 u32 sid
, eid
, exide
, rtr
;
413 u8 buf
[SPI_TRANSFER_BUF_LEN
];
415 exide
= (frame
->can_id
& CAN_EFF_FLAG
) ? 1 : 0; /* Extended ID Enable */
417 sid
= (frame
->can_id
& CAN_EFF_MASK
) >> 18;
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 */
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
);
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);
439 static void mcp251x_hw_rx_frame(struct spi_device
*spi
, u8
*buf
,
442 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
444 if (mcp251x_is_2510(spi
)) {
447 for (i
= 1; i
< RXBDAT_OFF
; i
++)
448 buf
[i
] = mcp251x_read_reg(spi
, RXBCTRL(buf_idx
) + i
);
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
);
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
);
460 static void mcp251x_hw_rx(struct spi_device
*spi
, int buf_idx
)
462 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
464 struct can_frame
*frame
;
465 u8 buf
[SPI_TRANSFER_BUF_LEN
];
467 skb
= alloc_can_skb(priv
->net
, &frame
);
469 dev_err(&spi
->dev
, "cannot allocate RX skb\n");
470 priv
->net
->stats
.rx_dropped
++;
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
;
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
;
490 /* Standard ID format */
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
;
498 frame
->can_dlc
= get_can_dlc(buf
[RXBDLC_OFF
] & RXBDLC_LEN_MASK
);
499 memcpy(frame
->data
, buf
+ RXBDAT_OFF
, frame
->can_dlc
);
501 priv
->net
->stats
.rx_packets
++;
502 priv
->net
->stats
.rx_bytes
+= frame
->can_dlc
;
504 can_led_event(priv
->net
, CAN_LED_EVENT_RX
);
509 static void mcp251x_hw_sleep(struct spi_device
*spi
)
511 mcp251x_write_reg(spi
, CANCTRL
, CANCTRL_REQOP_SLEEP
);
514 static netdev_tx_t
mcp251x_hard_start_xmit(struct sk_buff
*skb
,
515 struct net_device
*net
)
517 struct mcp251x_priv
*priv
= netdev_priv(net
);
518 struct spi_device
*spi
= priv
->spi
;
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
;
525 if (can_dropped_invalid_skb(net
, skb
))
528 netif_stop_queue(net
);
530 queue_work(priv
->wq
, &priv
->tx_work
);
535 static int mcp251x_do_set_mode(struct net_device
*net
, enum can_mode mode
)
537 struct mcp251x_priv
*priv
= netdev_priv(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
);
556 static int mcp251x_set_normal_mode(struct spi_device
*spi
)
558 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
559 unsigned long timeout
;
561 /* Enable interrupts */
562 mcp251x_write_reg(spi
, CANINTE
,
563 CANINTE_ERRIE
| CANINTE_TX2IE
| CANINTE_TX1IE
|
564 CANINTE_TX0IE
| CANINTE_RX1IE
| CANINTE_RX0IE
);
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
);
573 /* Put device into normal mode */
574 mcp251x_write_reg(spi
, CANCTRL
, CANCTRL_REQOP_NORMAL
);
576 /* Wait for the device to enter normal mode */
577 timeout
= jiffies
+ HZ
;
578 while (mcp251x_read_reg(spi
, CANSTAT
) & CANCTRL_REQOP_MASK
) {
580 if (time_after(jiffies
, timeout
)) {
581 dev_err(&spi
->dev
, "MCP251x didn't"
582 " enter in normal mode\n");
587 priv
->can
.state
= CAN_STATE_ERROR_ACTIVE
;
591 static int mcp251x_do_set_bittiming(struct net_device
*net
)
593 struct mcp251x_priv
*priv
= netdev_priv(net
);
594 struct can_bittiming
*bt
= &priv
->can
.bittiming
;
595 struct spi_device
*spi
= priv
->spi
;
597 mcp251x_write_reg(spi
, CNF1
, ((bt
->sjw
- 1) << CNF1_SJW_SHIFT
) |
599 mcp251x_write_reg(spi
, CNF2
, CNF2_BTLMODE
|
600 (priv
->can
.ctrlmode
& CAN_CTRLMODE_3_SAMPLES
?
602 ((bt
->phase_seg1
- 1) << CNF2_PS1_SHIFT
) |
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
));
614 static int mcp251x_setup(struct net_device
*net
, struct mcp251x_priv
*priv
,
615 struct spi_device
*spi
)
617 mcp251x_do_set_bittiming(net
);
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
);
626 static int mcp251x_hw_reset(struct spi_device
*spi
)
628 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
632 /* Wait for oscillator startup timer after power up */
633 mdelay(MCP251X_OST_DELAY_MS
);
635 priv
->spi_tx_buf
[0] = INSTRUCTION_RESET
;
636 ret
= mcp251x_spi_trans(spi
, 1);
640 /* Wait for oscillator startup timer after reset */
641 mdelay(MCP251X_OST_DELAY_MS
);
643 reg
= mcp251x_read_reg(spi
, CANSTAT
);
644 if ((reg
& CANCTRL_REQOP_MASK
) != CANCTRL_REQOP_CONF
)
650 static int mcp251x_hw_probe(struct spi_device
*spi
)
655 ret
= mcp251x_hw_reset(spi
);
659 ctrl
= mcp251x_read_reg(spi
, CANCTRL
);
661 dev_dbg(&spi
->dev
, "CANCTRL 0x%02x\n", ctrl
);
663 /* Check for power up default value */
664 if ((ctrl
& 0x17) != 0x07)
670 static int mcp251x_power_enable(struct regulator
*reg
, int enable
)
672 if (IS_ERR_OR_NULL(reg
))
676 return regulator_enable(reg
);
678 return regulator_disable(reg
);
681 static void mcp251x_open_clean(struct net_device
*net
)
683 struct mcp251x_priv
*priv
= netdev_priv(net
);
684 struct spi_device
*spi
= priv
->spi
;
686 free_irq(spi
->irq
, priv
);
687 mcp251x_hw_sleep(spi
);
688 mcp251x_power_enable(priv
->transceiver
, 0);
692 static int mcp251x_stop(struct net_device
*net
)
694 struct mcp251x_priv
*priv
= netdev_priv(net
);
695 struct spi_device
*spi
= priv
->spi
;
699 priv
->force_quit
= 1;
700 free_irq(spi
->irq
, priv
);
701 destroy_workqueue(priv
->wq
);
704 mutex_lock(&priv
->mcp_lock
);
706 /* Disable and clear pending interrupts */
707 mcp251x_write_reg(spi
, CANINTE
, 0x00);
708 mcp251x_write_reg(spi
, CANINTF
, 0x00);
710 mcp251x_write_reg(spi
, TXBCTRL(0), 0);
713 mcp251x_hw_sleep(spi
);
715 mcp251x_power_enable(priv
->transceiver
, 0);
717 priv
->can
.state
= CAN_STATE_STOPPED
;
719 mutex_unlock(&priv
->mcp_lock
);
721 can_led_event(net
, CAN_LED_EVENT_STOP
);
726 static void mcp251x_error_skb(struct net_device
*net
, int can_id
, int data1
)
729 struct can_frame
*frame
;
731 skb
= alloc_can_err_skb(net
, &frame
);
733 frame
->can_id
|= can_id
;
734 frame
->data
[1] = data1
;
737 netdev_err(net
, "cannot allocate error skb\n");
741 static void mcp251x_tx_work_handler(struct work_struct
*ws
)
743 struct mcp251x_priv
*priv
= container_of(ws
, struct mcp251x_priv
,
745 struct spi_device
*spi
= priv
->spi
;
746 struct net_device
*net
= priv
->net
;
747 struct can_frame
*frame
;
749 mutex_lock(&priv
->mcp_lock
);
751 if (priv
->can
.state
== CAN_STATE_BUS_OFF
) {
754 frame
= (struct can_frame
*)priv
->tx_skb
->data
;
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);
764 mutex_unlock(&priv
->mcp_lock
);
767 static void mcp251x_restart_work_handler(struct work_struct
*ws
)
769 struct mcp251x_priv
*priv
= container_of(ws
, struct mcp251x_priv
,
771 struct spi_device
*spi
= priv
->spi
;
772 struct net_device
*net
= priv
->net
;
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
);
783 mcp251x_set_normal_mode(spi
);
784 netif_wake_queue(net
);
786 mcp251x_hw_sleep(spi
);
788 priv
->after_suspend
= 0;
789 priv
->force_quit
= 0;
792 if (priv
->restart_tx
) {
793 priv
->restart_tx
= 0;
794 mcp251x_write_reg(spi
, TXBCTRL(0), 0);
796 netif_wake_queue(net
);
797 mcp251x_error_skb(net
, CAN_ERR_RESTARTED
, 0);
799 mutex_unlock(&priv
->mcp_lock
);
802 static irqreturn_t
mcp251x_can_ist(int irq
, void *dev_id
)
804 struct mcp251x_priv
*priv
= dev_id
;
805 struct spi_device
*spi
= priv
->spi
;
806 struct net_device
*net
= priv
->net
;
808 mutex_lock(&priv
->mcp_lock
);
809 while (!priv
->force_quit
) {
810 enum can_state new_state
;
813 int can_id
= 0, data1
= 0;
815 mcp251x_read_2regs(spi
, CANINTF
, &intf
, &eflag
);
817 /* mask out flags we don't care about */
818 intf
&= CANINTF_RX
| CANINTF_TX
| CANINTF_ERR
;
820 /* receive buffer 0 */
821 if (intf
& CANINTF_RX0IF
) {
822 mcp251x_hw_rx(spi
, 0);
824 * Free one buffer ASAP
825 * (The MCP2515 does this automatically.)
827 if (mcp251x_is_2510(spi
))
828 mcp251x_write_bits(spi
, CANINTF
, CANINTF_RX0IF
, 0x00);
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
;
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
);
843 mcp251x_write_bits(spi
, CANINTF
, clear_intf
, 0x00);
846 mcp251x_write_bits(spi
, EFLG
, eflag
, 0x00);
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
;
869 new_state
= CAN_STATE_ERROR_ACTIVE
;
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
++;
886 priv
->can
.state
= new_state
;
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
++;
895 if (eflag
& EFLG_RX1OVR
) {
896 net
->stats
.rx_over_errors
++;
897 net
->stats
.rx_errors
++;
899 can_id
|= CAN_ERR_CRTL
;
900 data1
|= CAN_ERR_CRTL_RX_OVERFLOW
;
902 mcp251x_error_skb(net
, can_id
, data1
);
905 if (priv
->can
.state
== CAN_STATE_BUS_OFF
) {
906 if (priv
->can
.restart_ms
== 0) {
907 priv
->force_quit
= 1;
909 mcp251x_hw_sleep(spi
);
917 if (intf
& CANINTF_TX
) {
918 net
->stats
.tx_packets
++;
919 net
->stats
.tx_bytes
+= priv
->tx_len
- 1;
920 can_led_event(net
, CAN_LED_EVENT_TX
);
922 can_get_echo_skb(net
, 0);
925 netif_wake_queue(net
);
929 mutex_unlock(&priv
->mcp_lock
);
933 static int mcp251x_open(struct net_device
*net
)
935 struct mcp251x_priv
*priv
= netdev_priv(net
);
936 struct spi_device
*spi
= priv
->spi
;
937 unsigned long flags
= IRQF_ONESHOT
| IRQF_TRIGGER_FALLING
;
940 ret
= open_candev(net
);
942 dev_err(&spi
->dev
, "unable to set initial baudrate!\n");
946 mutex_lock(&priv
->mcp_lock
);
947 mcp251x_power_enable(priv
->transceiver
, 1);
949 priv
->force_quit
= 0;
953 ret
= request_threaded_irq(spi
->irq
, NULL
, mcp251x_can_ist
,
954 flags
| IRQF_ONESHOT
, DEVICE_NAME
, priv
);
956 dev_err(&spi
->dev
, "failed to acquire irq %d\n", spi
->irq
);
957 mcp251x_power_enable(priv
->transceiver
, 0);
962 priv
->wq
= create_freezable_workqueue("mcp251x_wq");
963 INIT_WORK(&priv
->tx_work
, mcp251x_tx_work_handler
);
964 INIT_WORK(&priv
->restart_work
, mcp251x_restart_work_handler
);
966 ret
= mcp251x_hw_reset(spi
);
968 mcp251x_open_clean(net
);
971 ret
= mcp251x_setup(net
, priv
, spi
);
973 mcp251x_open_clean(net
);
976 ret
= mcp251x_set_normal_mode(spi
);
978 mcp251x_open_clean(net
);
982 can_led_event(net
, CAN_LED_EVENT_OPEN
);
984 netif_wake_queue(net
);
987 mutex_unlock(&priv
->mcp_lock
);
991 static const struct net_device_ops mcp251x_netdev_ops
= {
992 .ndo_open
= mcp251x_open
,
993 .ndo_stop
= mcp251x_stop
,
994 .ndo_start_xmit
= mcp251x_hard_start_xmit
,
995 .ndo_change_mtu
= can_change_mtu
,
998 static const struct of_device_id mcp251x_of_match
[] = {
1000 .compatible
= "microchip,mcp2510",
1001 .data
= (void *)CAN_MCP251X_MCP2510
,
1004 .compatible
= "microchip,mcp2515",
1005 .data
= (void *)CAN_MCP251X_MCP2515
,
1009 MODULE_DEVICE_TABLE(of
, mcp251x_of_match
);
1011 static const struct spi_device_id mcp251x_id_table
[] = {
1014 .driver_data
= (kernel_ulong_t
)CAN_MCP251X_MCP2510
,
1018 .driver_data
= (kernel_ulong_t
)CAN_MCP251X_MCP2515
,
1022 MODULE_DEVICE_TABLE(spi
, mcp251x_id_table
);
1024 static int mcp251x_can_probe(struct spi_device
*spi
)
1026 const struct of_device_id
*of_id
= of_match_device(mcp251x_of_match
,
1028 struct mcp251x_platform_data
*pdata
= dev_get_platdata(&spi
->dev
);
1029 struct net_device
*net
;
1030 struct mcp251x_priv
*priv
;
1034 clk
= devm_clk_get(&spi
->dev
, NULL
);
1037 freq
= pdata
->oscillator_frequency
;
1039 return PTR_ERR(clk
);
1041 freq
= clk_get_rate(clk
);
1045 if (freq
< 1000000 || freq
> 25000000)
1048 /* Allocate can/net device */
1049 net
= alloc_candev(sizeof(struct mcp251x_priv
), TX_ECHO_SKB_MAX
);
1054 ret
= clk_prepare_enable(clk
);
1059 net
->netdev_ops
= &mcp251x_netdev_ops
;
1060 net
->flags
|= IFF_ECHO
;
1062 priv
= netdev_priv(net
);
1063 priv
->can
.bittiming_const
= &mcp251x_bittiming_const
;
1064 priv
->can
.do_set_mode
= mcp251x_do_set_mode
;
1065 priv
->can
.clock
.freq
= freq
/ 2;
1066 priv
->can
.ctrlmode_supported
= CAN_CTRLMODE_3_SAMPLES
|
1067 CAN_CTRLMODE_LOOPBACK
| CAN_CTRLMODE_LISTENONLY
;
1069 priv
->model
= (enum mcp251x_model
)of_id
->data
;
1071 priv
->model
= spi_get_device_id(spi
)->driver_data
;
1075 spi_set_drvdata(spi
, priv
);
1077 /* Configure the SPI bus */
1078 spi
->bits_per_word
= 8;
1079 if (mcp251x_is_2510(spi
))
1080 spi
->max_speed_hz
= spi
->max_speed_hz
? : 5 * 1000 * 1000;
1082 spi
->max_speed_hz
= spi
->max_speed_hz
? : 10 * 1000 * 1000;
1083 ret
= spi_setup(spi
);
1087 priv
->power
= devm_regulator_get(&spi
->dev
, "vdd");
1088 priv
->transceiver
= devm_regulator_get(&spi
->dev
, "xceiver");
1089 if ((PTR_ERR(priv
->power
) == -EPROBE_DEFER
) ||
1090 (PTR_ERR(priv
->transceiver
) == -EPROBE_DEFER
)) {
1091 ret
= -EPROBE_DEFER
;
1095 ret
= mcp251x_power_enable(priv
->power
, 1);
1100 mutex_init(&priv
->mcp_lock
);
1102 /* If requested, allocate DMA buffers */
1103 if (mcp251x_enable_dma
) {
1104 spi
->dev
.coherent_dma_mask
= ~0;
1107 * Minimum coherent DMA allocation is PAGE_SIZE, so allocate
1108 * that much and share it between Tx and Rx DMA buffers.
1110 priv
->spi_tx_buf
= dmam_alloc_coherent(&spi
->dev
,
1115 if (priv
->spi_tx_buf
) {
1116 priv
->spi_rx_buf
= (priv
->spi_tx_buf
+ (PAGE_SIZE
/ 2));
1117 priv
->spi_rx_dma
= (dma_addr_t
)(priv
->spi_tx_dma
+
1120 /* Fall back to non-DMA */
1121 mcp251x_enable_dma
= 0;
1125 /* Allocate non-DMA buffers */
1126 if (!mcp251x_enable_dma
) {
1127 priv
->spi_tx_buf
= devm_kzalloc(&spi
->dev
, SPI_TRANSFER_BUF_LEN
,
1129 if (!priv
->spi_tx_buf
) {
1133 priv
->spi_rx_buf
= devm_kzalloc(&spi
->dev
, SPI_TRANSFER_BUF_LEN
,
1135 if (!priv
->spi_rx_buf
) {
1141 SET_NETDEV_DEV(net
, &spi
->dev
);
1143 /* Here is OK to not lock the MCP, no one knows about it yet */
1144 ret
= mcp251x_hw_probe(spi
);
1148 mcp251x_hw_sleep(spi
);
1150 ret
= register_candev(net
);
1154 devm_can_led_init(net
);
1159 mcp251x_power_enable(priv
->power
, 0);
1163 clk_disable_unprepare(clk
);
1171 static int mcp251x_can_remove(struct spi_device
*spi
)
1173 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
1174 struct net_device
*net
= priv
->net
;
1176 unregister_candev(net
);
1178 mcp251x_power_enable(priv
->power
, 0);
1180 if (!IS_ERR(priv
->clk
))
1181 clk_disable_unprepare(priv
->clk
);
1188 static int __maybe_unused
mcp251x_can_suspend(struct device
*dev
)
1190 struct spi_device
*spi
= to_spi_device(dev
);
1191 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
1192 struct net_device
*net
= priv
->net
;
1194 priv
->force_quit
= 1;
1195 disable_irq(spi
->irq
);
1197 * Note: at this point neither IST nor workqueues are running.
1198 * open/stop cannot be called anyway so locking is not needed
1200 if (netif_running(net
)) {
1201 netif_device_detach(net
);
1203 mcp251x_hw_sleep(spi
);
1204 mcp251x_power_enable(priv
->transceiver
, 0);
1205 priv
->after_suspend
= AFTER_SUSPEND_UP
;
1207 priv
->after_suspend
= AFTER_SUSPEND_DOWN
;
1210 if (!IS_ERR_OR_NULL(priv
->power
)) {
1211 regulator_disable(priv
->power
);
1212 priv
->after_suspend
|= AFTER_SUSPEND_POWER
;
1218 static int __maybe_unused
mcp251x_can_resume(struct device
*dev
)
1220 struct spi_device
*spi
= to_spi_device(dev
);
1221 struct mcp251x_priv
*priv
= spi_get_drvdata(spi
);
1223 if (priv
->after_suspend
& AFTER_SUSPEND_POWER
) {
1224 mcp251x_power_enable(priv
->power
, 1);
1225 queue_work(priv
->wq
, &priv
->restart_work
);
1227 if (priv
->after_suspend
& AFTER_SUSPEND_UP
) {
1228 mcp251x_power_enable(priv
->transceiver
, 1);
1229 queue_work(priv
->wq
, &priv
->restart_work
);
1231 priv
->after_suspend
= 0;
1234 priv
->force_quit
= 0;
1235 enable_irq(spi
->irq
);
1239 static SIMPLE_DEV_PM_OPS(mcp251x_can_pm_ops
, mcp251x_can_suspend
,
1240 mcp251x_can_resume
);
1242 static struct spi_driver mcp251x_can_driver
= {
1244 .name
= DEVICE_NAME
,
1245 .owner
= THIS_MODULE
,
1246 .of_match_table
= mcp251x_of_match
,
1247 .pm
= &mcp251x_can_pm_ops
,
1249 .id_table
= mcp251x_id_table
,
1250 .probe
= mcp251x_can_probe
,
1251 .remove
= mcp251x_can_remove
,
1253 module_spi_driver(mcp251x_can_driver
);
1255 MODULE_AUTHOR("Chris Elston <celston@katalix.com>, "
1256 "Christian Pellegrin <chripell@evolware.org>");
1257 MODULE_DESCRIPTION("Microchip 251x CAN driver");
1258 MODULE_LICENSE("GPL v2");