2 * CAN bus driver for Microchip 251x/25625 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 * // "mcp2515" or "mcp25625" 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 RXFSID(n) ((n < 3) ? 0 : 4)
194 #define RXFSIDH(n) ((n) * 4 + RXFSID(n))
195 #define RXFSIDL(n) ((n) * 4 + 1 + RXFSID(n))
196 #define RXFEID8(n) ((n) * 4 + 2 + RXFSID(n))
197 #define RXFEID0(n) ((n) * 4 + 3 + RXFSID(n))
198 #define RXMSIDH(n) ((n) * 4 + 0x20)
199 #define RXMSIDL(n) ((n) * 4 + 0x21)
200 #define RXMEID8(n) ((n) * 4 + 0x22)
201 #define RXMEID0(n) ((n) * 4 + 0x23)
203 #define GET_BYTE(val, byte) \
204 (((val) >> ((byte) * 8)) & 0xff)
205 #define SET_BYTE(val, byte) \
206 (((val) & 0xff) << ((byte) * 8))
209 * Buffer size required for the largest SPI transfer (i.e., reading a
212 #define CAN_FRAME_MAX_DATA_LEN 8
213 #define SPI_TRANSFER_BUF_LEN (6 + CAN_FRAME_MAX_DATA_LEN)
214 #define CAN_FRAME_MAX_BITS 128
216 #define TX_ECHO_SKB_MAX 1
218 #define MCP251X_OST_DELAY_MS (5)
220 #define DEVICE_NAME "mcp251x"
222 static int mcp251x_enable_dma; /* Enable SPI DMA. Default: 0 (Off) */
223 module_param(mcp251x_enable_dma, int, S_IRUGO);
224 MODULE_PARM_DESC(mcp251x_enable_dma, "Enable SPI DMA. Default: 0 (Off)");
226 static const struct can_bittiming_const mcp251x_bittiming_const = {
239 CAN_MCP251X_MCP2510 = 0x2510,
240 CAN_MCP251X_MCP2515 = 0x2515,
241 CAN_MCP251X_MCP25625 = 0x25625,
244 struct mcp251x_priv {
246 struct net_device *net;
247 struct spi_device *spi;
248 enum mcp251x_model model;
250 struct mutex mcp_lock; /* SPI device lock */
254 dma_addr_t spi_tx_dma;
255 dma_addr_t spi_rx_dma;
257 struct sk_buff *tx_skb;
260 struct workqueue_struct *wq;
261 struct work_struct tx_work;
262 struct work_struct restart_work;
266 #define AFTER_SUSPEND_UP 1
267 #define AFTER_SUSPEND_DOWN 2
268 #define AFTER_SUSPEND_POWER 4
269 #define AFTER_SUSPEND_RESTART 8
271 struct regulator *power;
272 struct regulator *transceiver;
276 #define MCP251X_IS(_model) \
277 static inline int mcp251x_is_##_model(struct spi_device *spi) \
279 struct mcp251x_priv *priv = spi_get_drvdata(spi); \
280 return priv->model == CAN_MCP251X_MCP##_model; \
285 static void mcp251x_clean(struct net_device *net)
287 struct mcp251x_priv *priv = netdev_priv(net);
289 if (priv->tx_skb || priv->tx_len)
290 net->stats.tx_errors++;
292 dev_kfree_skb(priv->tx_skb);
294 can_free_echo_skb(priv->net, 0);
300 * Note about handling of error return of mcp251x_spi_trans: accessing
301 * registers via SPI is not really different conceptually than using
302 * normal I/O assembler instructions, although it's much more
303 * complicated from a practical POV. So it's not advisable to always
304 * check the return value of this function. Imagine that every
305 * read{b,l}, write{b,l} and friends would be bracketed in "if ( < 0)
306 * error();", it would be a great mess (well there are some situation
307 * when exception handling C++ like could be useful after all). So we
308 * just check that transfers are OK at the beginning of our
309 * conversation with the chip and to avoid doing really nasty things
310 * (like injecting bogus packets in the network stack).
312 static int mcp251x_spi_trans(struct spi_device *spi, int len)
314 struct mcp251x_priv *priv = spi_get_drvdata(spi);
315 struct spi_transfer t = {
316 .tx_buf = priv->spi_tx_buf,
317 .rx_buf = priv->spi_rx_buf,
321 struct spi_message m;
324 spi_message_init(&m);
326 if (mcp251x_enable_dma) {
327 t.tx_dma = priv->spi_tx_dma;
328 t.rx_dma = priv->spi_rx_dma;
332 spi_message_add_tail(&t, &m);
334 ret = spi_sync(spi, &m);
336 dev_err(&spi->dev, "spi transfer failed: ret = %d\n", ret);
340 static u8 mcp251x_read_reg(struct spi_device *spi, uint8_t reg)
342 struct mcp251x_priv *priv = spi_get_drvdata(spi);
345 priv->spi_tx_buf[0] = INSTRUCTION_READ;
346 priv->spi_tx_buf[1] = reg;
348 mcp251x_spi_trans(spi, 3);
349 val = priv->spi_rx_buf[2];
354 static void mcp251x_read_2regs(struct spi_device *spi, uint8_t reg,
355 uint8_t *v1, uint8_t *v2)
357 struct mcp251x_priv *priv = spi_get_drvdata(spi);
359 priv->spi_tx_buf[0] = INSTRUCTION_READ;
360 priv->spi_tx_buf[1] = reg;
362 mcp251x_spi_trans(spi, 4);
364 *v1 = priv->spi_rx_buf[2];
365 *v2 = priv->spi_rx_buf[3];
368 static void mcp251x_write_reg(struct spi_device *spi, u8 reg, uint8_t val)
370 struct mcp251x_priv *priv = spi_get_drvdata(spi);
372 priv->spi_tx_buf[0] = INSTRUCTION_WRITE;
373 priv->spi_tx_buf[1] = reg;
374 priv->spi_tx_buf[2] = val;
376 mcp251x_spi_trans(spi, 3);
379 static void mcp251x_write_bits(struct spi_device *spi, u8 reg,
380 u8 mask, uint8_t val)
382 struct mcp251x_priv *priv = spi_get_drvdata(spi);
384 priv->spi_tx_buf[0] = INSTRUCTION_BIT_MODIFY;
385 priv->spi_tx_buf[1] = reg;
386 priv->spi_tx_buf[2] = mask;
387 priv->spi_tx_buf[3] = val;
389 mcp251x_spi_trans(spi, 4);
392 static void mcp251x_hw_tx_frame(struct spi_device *spi, u8 *buf,
393 int len, int tx_buf_idx)
395 struct mcp251x_priv *priv = spi_get_drvdata(spi);
397 if (mcp251x_is_2510(spi)) {
400 for (i = 1; i < TXBDAT_OFF + len; i++)
401 mcp251x_write_reg(spi, TXBCTRL(tx_buf_idx) + i,
404 memcpy(priv->spi_tx_buf, buf, TXBDAT_OFF + len);
405 mcp251x_spi_trans(spi, TXBDAT_OFF + len);
409 static void mcp251x_hw_tx(struct spi_device *spi, struct can_frame *frame,
412 struct mcp251x_priv *priv = spi_get_drvdata(spi);
413 u32 sid, eid, exide, rtr;
414 u8 buf[SPI_TRANSFER_BUF_LEN];
416 exide = (frame->can_id & CAN_EFF_FLAG) ? 1 : 0; /* Extended ID Enable */
418 sid = (frame->can_id & CAN_EFF_MASK) >> 18;
420 sid = frame->can_id & CAN_SFF_MASK; /* Standard ID */
421 eid = frame->can_id & CAN_EFF_MASK; /* Extended ID */
422 rtr = (frame->can_id & CAN_RTR_FLAG) ? 1 : 0; /* Remote transmission */
424 buf[TXBCTRL_OFF] = INSTRUCTION_LOAD_TXB(tx_buf_idx);
425 buf[TXBSIDH_OFF] = sid >> SIDH_SHIFT;
426 buf[TXBSIDL_OFF] = ((sid & SIDL_SID_MASK) << SIDL_SID_SHIFT) |
427 (exide << SIDL_EXIDE_SHIFT) |
428 ((eid >> SIDL_EID_SHIFT) & SIDL_EID_MASK);
429 buf[TXBEID8_OFF] = GET_BYTE(eid, 1);
430 buf[TXBEID0_OFF] = GET_BYTE(eid, 0);
431 buf[TXBDLC_OFF] = (rtr << DLC_RTR_SHIFT) | frame->can_dlc;
432 memcpy(buf + TXBDAT_OFF, frame->data, frame->can_dlc);
433 mcp251x_hw_tx_frame(spi, buf, frame->can_dlc, tx_buf_idx);
435 /* use INSTRUCTION_RTS, to avoid "repeated frame problem" */
436 priv->spi_tx_buf[0] = INSTRUCTION_RTS(1 << tx_buf_idx);
437 mcp251x_spi_trans(priv->spi, 1);
440 static void mcp251x_hw_rx_frame(struct spi_device *spi, u8 *buf,
443 struct mcp251x_priv *priv = spi_get_drvdata(spi);
445 if (mcp251x_is_2510(spi)) {
448 for (i = 1; i < RXBDAT_OFF; i++)
449 buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i);
451 len = get_can_dlc(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK);
452 for (; i < (RXBDAT_OFF + len); i++)
453 buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i);
455 priv->spi_tx_buf[RXBCTRL_OFF] = INSTRUCTION_READ_RXB(buf_idx);
456 mcp251x_spi_trans(spi, SPI_TRANSFER_BUF_LEN);
457 memcpy(buf, priv->spi_rx_buf, SPI_TRANSFER_BUF_LEN);
461 static void mcp251x_hw_rx(struct spi_device *spi, int buf_idx)
463 struct mcp251x_priv *priv = spi_get_drvdata(spi);
465 struct can_frame *frame;
466 u8 buf[SPI_TRANSFER_BUF_LEN];
468 skb = alloc_can_skb(priv->net, &frame);
470 dev_err(&spi->dev, "cannot allocate RX skb\n");
471 priv->net->stats.rx_dropped++;
475 mcp251x_hw_rx_frame(spi, buf, buf_idx);
476 if (buf[RXBSIDL_OFF] & RXBSIDL_IDE) {
477 /* Extended ID format */
478 frame->can_id = CAN_EFF_FLAG;
480 /* Extended ID part */
481 SET_BYTE(buf[RXBSIDL_OFF] & RXBSIDL_EID, 2) |
482 SET_BYTE(buf[RXBEID8_OFF], 1) |
483 SET_BYTE(buf[RXBEID0_OFF], 0) |
484 /* Standard ID part */
485 (((buf[RXBSIDH_OFF] << RXBSIDH_SHIFT) |
486 (buf[RXBSIDL_OFF] >> RXBSIDL_SHIFT)) << 18);
487 /* Remote transmission request */
488 if (buf[RXBDLC_OFF] & RXBDLC_RTR)
489 frame->can_id |= CAN_RTR_FLAG;
491 /* Standard ID format */
493 (buf[RXBSIDH_OFF] << RXBSIDH_SHIFT) |
494 (buf[RXBSIDL_OFF] >> RXBSIDL_SHIFT);
495 if (buf[RXBSIDL_OFF] & RXBSIDL_SRR)
496 frame->can_id |= CAN_RTR_FLAG;
499 frame->can_dlc = get_can_dlc(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK);
500 memcpy(frame->data, buf + RXBDAT_OFF, frame->can_dlc);
502 priv->net->stats.rx_packets++;
503 priv->net->stats.rx_bytes += frame->can_dlc;
505 can_led_event(priv->net, CAN_LED_EVENT_RX);
510 static void mcp251x_hw_sleep(struct spi_device *spi)
512 mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_SLEEP);
515 static netdev_tx_t mcp251x_hard_start_xmit(struct sk_buff *skb,
516 struct net_device *net)
518 struct mcp251x_priv *priv = netdev_priv(net);
519 struct spi_device *spi = priv->spi;
521 if (priv->tx_skb || priv->tx_len) {
522 dev_warn(&spi->dev, "hard_xmit called while tx busy\n");
523 return NETDEV_TX_BUSY;
526 if (can_dropped_invalid_skb(net, skb))
529 netif_stop_queue(net);
531 queue_work(priv->wq, &priv->tx_work);
536 static int mcp251x_do_set_mode(struct net_device *net, enum can_mode mode)
538 struct mcp251x_priv *priv = netdev_priv(net);
543 /* We have to delay work since SPI I/O may sleep */
544 priv->can.state = CAN_STATE_ERROR_ACTIVE;
545 priv->restart_tx = 1;
546 if (priv->can.restart_ms == 0)
547 priv->after_suspend = AFTER_SUSPEND_RESTART;
548 queue_work(priv->wq, &priv->restart_work);
557 static int mcp251x_set_normal_mode(struct spi_device *spi)
559 struct mcp251x_priv *priv = spi_get_drvdata(spi);
560 unsigned long timeout;
562 /* Enable interrupts */
563 mcp251x_write_reg(spi, CANINTE,
564 CANINTE_ERRIE | CANINTE_TX2IE | CANINTE_TX1IE |
565 CANINTE_TX0IE | CANINTE_RX1IE | CANINTE_RX0IE);
567 if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
568 /* Put device into loopback mode */
569 mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LOOPBACK);
570 } else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) {
571 /* Put device into listen-only mode */
572 mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LISTEN_ONLY);
574 /* Put device into normal mode */
575 mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_NORMAL);
577 /* Wait for the device to enter normal mode */
578 timeout = jiffies + HZ;
579 while (mcp251x_read_reg(spi, CANSTAT) & CANCTRL_REQOP_MASK) {
581 if (time_after(jiffies, timeout)) {
582 dev_err(&spi->dev, "MCP251x didn't"
583 " enter in normal mode\n");
588 priv->can.state = CAN_STATE_ERROR_ACTIVE;
592 static int mcp251x_do_set_bittiming(struct net_device *net)
594 struct mcp251x_priv *priv = netdev_priv(net);
595 struct can_bittiming *bt = &priv->can.bittiming;
596 struct spi_device *spi = priv->spi;
598 mcp251x_write_reg(spi, CNF1, ((bt->sjw - 1) << CNF1_SJW_SHIFT) |
600 mcp251x_write_reg(spi, CNF2, CNF2_BTLMODE |
601 (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES ?
603 ((bt->phase_seg1 - 1) << CNF2_PS1_SHIFT) |
605 mcp251x_write_bits(spi, CNF3, CNF3_PHSEG2_MASK,
606 (bt->phase_seg2 - 1));
607 dev_dbg(&spi->dev, "CNF: 0x%02x 0x%02x 0x%02x\n",
608 mcp251x_read_reg(spi, CNF1),
609 mcp251x_read_reg(spi, CNF2),
610 mcp251x_read_reg(spi, CNF3));
615 static int mcp251x_setup(struct net_device *net, struct mcp251x_priv *priv,
616 struct spi_device *spi)
618 mcp251x_do_set_bittiming(net);
620 mcp251x_write_reg(spi, RXBCTRL(0),
621 RXBCTRL_BUKT | RXBCTRL_RXM0 | RXBCTRL_RXM1);
622 mcp251x_write_reg(spi, RXBCTRL(1),
623 RXBCTRL_RXM0 | RXBCTRL_RXM1);
627 static int mcp251x_hw_reset(struct spi_device *spi)
629 struct mcp251x_priv *priv = spi_get_drvdata(spi);
630 unsigned long timeout;
633 /* Wait for oscillator startup timer after power up */
634 mdelay(MCP251X_OST_DELAY_MS);
636 priv->spi_tx_buf[0] = INSTRUCTION_RESET;
637 ret = mcp251x_spi_trans(spi, 1);
641 /* Wait for oscillator startup timer after reset */
642 mdelay(MCP251X_OST_DELAY_MS);
644 /* Wait for reset to finish */
645 timeout = jiffies + HZ;
646 while ((mcp251x_read_reg(spi, CANSTAT) & CANCTRL_REQOP_MASK) !=
647 CANCTRL_REQOP_CONF) {
648 usleep_range(MCP251X_OST_DELAY_MS * 1000,
649 MCP251X_OST_DELAY_MS * 1000 * 2);
651 if (time_after(jiffies, timeout)) {
653 "MCP251x didn't enter in conf mode after reset\n");
660 static int mcp251x_hw_probe(struct spi_device *spi)
665 ret = mcp251x_hw_reset(spi);
669 ctrl = mcp251x_read_reg(spi, CANCTRL);
671 dev_dbg(&spi->dev, "CANCTRL 0x%02x\n", ctrl);
673 /* Check for power up default value */
674 if ((ctrl & 0x17) != 0x07)
680 static int mcp251x_power_enable(struct regulator *reg, int enable)
682 if (IS_ERR_OR_NULL(reg))
686 return regulator_enable(reg);
688 return regulator_disable(reg);
691 static void mcp251x_open_clean(struct net_device *net)
693 struct mcp251x_priv *priv = netdev_priv(net);
694 struct spi_device *spi = priv->spi;
696 free_irq(spi->irq, priv);
697 mcp251x_hw_sleep(spi);
698 mcp251x_power_enable(priv->transceiver, 0);
702 static int mcp251x_stop(struct net_device *net)
704 struct mcp251x_priv *priv = netdev_priv(net);
705 struct spi_device *spi = priv->spi;
709 priv->force_quit = 1;
710 free_irq(spi->irq, priv);
711 destroy_workqueue(priv->wq);
714 mutex_lock(&priv->mcp_lock);
716 /* Disable and clear pending interrupts */
717 mcp251x_write_reg(spi, CANINTE, 0x00);
718 mcp251x_write_reg(spi, CANINTF, 0x00);
720 mcp251x_write_reg(spi, TXBCTRL(0), 0);
723 mcp251x_hw_sleep(spi);
725 mcp251x_power_enable(priv->transceiver, 0);
727 priv->can.state = CAN_STATE_STOPPED;
729 mutex_unlock(&priv->mcp_lock);
731 can_led_event(net, CAN_LED_EVENT_STOP);
736 static void mcp251x_error_skb(struct net_device *net, int can_id, int data1)
739 struct can_frame *frame;
741 skb = alloc_can_err_skb(net, &frame);
743 frame->can_id |= can_id;
744 frame->data[1] = data1;
747 netdev_err(net, "cannot allocate error skb\n");
751 static void mcp251x_tx_work_handler(struct work_struct *ws)
753 struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv,
755 struct spi_device *spi = priv->spi;
756 struct net_device *net = priv->net;
757 struct can_frame *frame;
759 mutex_lock(&priv->mcp_lock);
761 if (priv->can.state == CAN_STATE_BUS_OFF) {
764 frame = (struct can_frame *)priv->tx_skb->data;
766 if (frame->can_dlc > CAN_FRAME_MAX_DATA_LEN)
767 frame->can_dlc = CAN_FRAME_MAX_DATA_LEN;
768 mcp251x_hw_tx(spi, frame, 0);
769 priv->tx_len = 1 + frame->can_dlc;
770 can_put_echo_skb(priv->tx_skb, net, 0);
774 mutex_unlock(&priv->mcp_lock);
777 static void mcp251x_restart_work_handler(struct work_struct *ws)
779 struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv,
781 struct spi_device *spi = priv->spi;
782 struct net_device *net = priv->net;
784 mutex_lock(&priv->mcp_lock);
785 if (priv->after_suspend) {
786 mcp251x_hw_reset(spi);
787 mcp251x_setup(net, priv, spi);
788 if (priv->after_suspend & AFTER_SUSPEND_RESTART) {
789 mcp251x_set_normal_mode(spi);
790 } else if (priv->after_suspend & AFTER_SUSPEND_UP) {
791 netif_device_attach(net);
793 mcp251x_set_normal_mode(spi);
794 netif_wake_queue(net);
796 mcp251x_hw_sleep(spi);
798 priv->after_suspend = 0;
799 priv->force_quit = 0;
802 if (priv->restart_tx) {
803 priv->restart_tx = 0;
804 mcp251x_write_reg(spi, TXBCTRL(0), 0);
806 netif_wake_queue(net);
807 mcp251x_error_skb(net, CAN_ERR_RESTARTED, 0);
809 mutex_unlock(&priv->mcp_lock);
812 static irqreturn_t mcp251x_can_ist(int irq, void *dev_id)
814 struct mcp251x_priv *priv = dev_id;
815 struct spi_device *spi = priv->spi;
816 struct net_device *net = priv->net;
818 mutex_lock(&priv->mcp_lock);
819 while (!priv->force_quit) {
820 enum can_state new_state;
823 int can_id = 0, data1 = 0;
825 mcp251x_read_2regs(spi, CANINTF, &intf, &eflag);
827 /* mask out flags we don't care about */
828 intf &= CANINTF_RX | CANINTF_TX | CANINTF_ERR;
830 /* receive buffer 0 */
831 if (intf & CANINTF_RX0IF) {
832 mcp251x_hw_rx(spi, 0);
833 /* Free one buffer ASAP
834 * (The MCP2515/25625 does this automatically.)
836 if (mcp251x_is_2510(spi))
837 mcp251x_write_bits(spi, CANINTF, CANINTF_RX0IF, 0x00);
840 /* receive buffer 1 */
841 if (intf & CANINTF_RX1IF) {
842 mcp251x_hw_rx(spi, 1);
843 /* The MCP2515/25625 does this automatically. */
844 if (mcp251x_is_2510(spi))
845 clear_intf |= CANINTF_RX1IF;
848 /* any error or tx interrupt we need to clear? */
849 if (intf & (CANINTF_ERR | CANINTF_TX))
850 clear_intf |= intf & (CANINTF_ERR | CANINTF_TX);
852 mcp251x_write_bits(spi, CANINTF, clear_intf, 0x00);
854 if (eflag & (EFLG_RX0OVR | EFLG_RX1OVR))
855 mcp251x_write_bits(spi, EFLG, eflag, 0x00);
857 /* Update can state */
858 if (eflag & EFLG_TXBO) {
859 new_state = CAN_STATE_BUS_OFF;
860 can_id |= CAN_ERR_BUSOFF;
861 } else if (eflag & EFLG_TXEP) {
862 new_state = CAN_STATE_ERROR_PASSIVE;
863 can_id |= CAN_ERR_CRTL;
864 data1 |= CAN_ERR_CRTL_TX_PASSIVE;
865 } else if (eflag & EFLG_RXEP) {
866 new_state = CAN_STATE_ERROR_PASSIVE;
867 can_id |= CAN_ERR_CRTL;
868 data1 |= CAN_ERR_CRTL_RX_PASSIVE;
869 } else if (eflag & EFLG_TXWAR) {
870 new_state = CAN_STATE_ERROR_WARNING;
871 can_id |= CAN_ERR_CRTL;
872 data1 |= CAN_ERR_CRTL_TX_WARNING;
873 } else if (eflag & EFLG_RXWAR) {
874 new_state = CAN_STATE_ERROR_WARNING;
875 can_id |= CAN_ERR_CRTL;
876 data1 |= CAN_ERR_CRTL_RX_WARNING;
878 new_state = CAN_STATE_ERROR_ACTIVE;
881 /* Update can state statistics */
882 switch (priv->can.state) {
883 case CAN_STATE_ERROR_ACTIVE:
884 if (new_state >= CAN_STATE_ERROR_WARNING &&
885 new_state <= CAN_STATE_BUS_OFF)
886 priv->can.can_stats.error_warning++;
887 case CAN_STATE_ERROR_WARNING: /* fallthrough */
888 if (new_state >= CAN_STATE_ERROR_PASSIVE &&
889 new_state <= CAN_STATE_BUS_OFF)
890 priv->can.can_stats.error_passive++;
895 priv->can.state = new_state;
897 if (intf & CANINTF_ERRIF) {
898 /* Handle overflow counters */
899 if (eflag & (EFLG_RX0OVR | EFLG_RX1OVR)) {
900 if (eflag & EFLG_RX0OVR) {
901 net->stats.rx_over_errors++;
902 net->stats.rx_errors++;
904 if (eflag & EFLG_RX1OVR) {
905 net->stats.rx_over_errors++;
906 net->stats.rx_errors++;
908 can_id |= CAN_ERR_CRTL;
909 data1 |= CAN_ERR_CRTL_RX_OVERFLOW;
911 mcp251x_error_skb(net, can_id, data1);
914 if (priv->can.state == CAN_STATE_BUS_OFF) {
915 if (priv->can.restart_ms == 0) {
916 priv->force_quit = 1;
917 priv->can.can_stats.bus_off++;
919 mcp251x_hw_sleep(spi);
927 if (intf & CANINTF_TX) {
928 net->stats.tx_packets++;
929 net->stats.tx_bytes += priv->tx_len - 1;
930 can_led_event(net, CAN_LED_EVENT_TX);
932 can_get_echo_skb(net, 0);
935 netif_wake_queue(net);
939 mutex_unlock(&priv->mcp_lock);
943 static int mcp251x_open(struct net_device *net)
945 struct mcp251x_priv *priv = netdev_priv(net);
946 struct spi_device *spi = priv->spi;
947 unsigned long flags = IRQF_ONESHOT | IRQF_TRIGGER_FALLING;
950 ret = open_candev(net);
952 dev_err(&spi->dev, "unable to set initial baudrate!\n");
956 mutex_lock(&priv->mcp_lock);
957 mcp251x_power_enable(priv->transceiver, 1);
959 priv->force_quit = 0;
963 ret = request_threaded_irq(spi->irq, NULL, mcp251x_can_ist,
964 flags | IRQF_ONESHOT, DEVICE_NAME, priv);
966 dev_err(&spi->dev, "failed to acquire irq %d\n", spi->irq);
967 mcp251x_power_enable(priv->transceiver, 0);
972 priv->wq = alloc_workqueue("mcp251x_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM,
974 INIT_WORK(&priv->tx_work, mcp251x_tx_work_handler);
975 INIT_WORK(&priv->restart_work, mcp251x_restart_work_handler);
977 ret = mcp251x_hw_reset(spi);
979 mcp251x_open_clean(net);
982 ret = mcp251x_setup(net, priv, spi);
984 mcp251x_open_clean(net);
987 ret = mcp251x_set_normal_mode(spi);
989 mcp251x_open_clean(net);
993 can_led_event(net, CAN_LED_EVENT_OPEN);
995 netif_wake_queue(net);
998 mutex_unlock(&priv->mcp_lock);
1002 static const struct net_device_ops mcp251x_netdev_ops = {
1003 .ndo_open = mcp251x_open,
1004 .ndo_stop = mcp251x_stop,
1005 .ndo_start_xmit = mcp251x_hard_start_xmit,
1006 .ndo_change_mtu = can_change_mtu,
1009 static const struct of_device_id mcp251x_of_match[] = {
1011 .compatible = "microchip,mcp2510",
1012 .data = (void *)CAN_MCP251X_MCP2510,
1015 .compatible = "microchip,mcp2515",
1016 .data = (void *)CAN_MCP251X_MCP2515,
1019 .compatible = "microchip,mcp25625",
1020 .data = (void *)CAN_MCP251X_MCP25625,
1024 MODULE_DEVICE_TABLE(of, mcp251x_of_match);
1026 static const struct spi_device_id mcp251x_id_table[] = {
1029 .driver_data = (kernel_ulong_t)CAN_MCP251X_MCP2510,
1033 .driver_data = (kernel_ulong_t)CAN_MCP251X_MCP2515,
1037 .driver_data = (kernel_ulong_t)CAN_MCP251X_MCP25625,
1041 MODULE_DEVICE_TABLE(spi, mcp251x_id_table);
1043 static int mcp251x_can_probe(struct spi_device *spi)
1045 const struct of_device_id *of_id = of_match_device(mcp251x_of_match,
1047 struct mcp251x_platform_data *pdata = dev_get_platdata(&spi->dev);
1048 struct net_device *net;
1049 struct mcp251x_priv *priv;
1053 clk = devm_clk_get(&spi->dev, NULL);
1056 freq = pdata->oscillator_frequency;
1058 return PTR_ERR(clk);
1060 freq = clk_get_rate(clk);
1064 if (freq < 1000000 || freq > 25000000)
1067 /* Allocate can/net device */
1068 net = alloc_candev(sizeof(struct mcp251x_priv), TX_ECHO_SKB_MAX);
1073 ret = clk_prepare_enable(clk);
1078 net->netdev_ops = &mcp251x_netdev_ops;
1079 net->flags |= IFF_ECHO;
1081 priv = netdev_priv(net);
1082 priv->can.bittiming_const = &mcp251x_bittiming_const;
1083 priv->can.do_set_mode = mcp251x_do_set_mode;
1084 priv->can.clock.freq = freq / 2;
1085 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
1086 CAN_CTRLMODE_LOOPBACK | CAN_CTRLMODE_LISTENONLY;
1088 priv->model = (enum mcp251x_model)of_id->data;
1090 priv->model = spi_get_device_id(spi)->driver_data;
1094 spi_set_drvdata(spi, priv);
1096 /* Configure the SPI bus */
1097 spi->bits_per_word = 8;
1098 if (mcp251x_is_2510(spi))
1099 spi->max_speed_hz = spi->max_speed_hz ? : 5 * 1000 * 1000;
1101 spi->max_speed_hz = spi->max_speed_hz ? : 10 * 1000 * 1000;
1102 ret = spi_setup(spi);
1106 priv->power = devm_regulator_get_optional(&spi->dev, "vdd");
1107 priv->transceiver = devm_regulator_get_optional(&spi->dev, "xceiver");
1108 if ((PTR_ERR(priv->power) == -EPROBE_DEFER) ||
1109 (PTR_ERR(priv->transceiver) == -EPROBE_DEFER)) {
1110 ret = -EPROBE_DEFER;
1114 ret = mcp251x_power_enable(priv->power, 1);
1119 mutex_init(&priv->mcp_lock);
1121 /* If requested, allocate DMA buffers */
1122 if (mcp251x_enable_dma) {
1123 spi->dev.coherent_dma_mask = ~0;
1126 * Minimum coherent DMA allocation is PAGE_SIZE, so allocate
1127 * that much and share it between Tx and Rx DMA buffers.
1129 priv->spi_tx_buf = dmam_alloc_coherent(&spi->dev,
1134 if (priv->spi_tx_buf) {
1135 priv->spi_rx_buf = (priv->spi_tx_buf + (PAGE_SIZE / 2));
1136 priv->spi_rx_dma = (dma_addr_t)(priv->spi_tx_dma +
1139 /* Fall back to non-DMA */
1140 mcp251x_enable_dma = 0;
1144 /* Allocate non-DMA buffers */
1145 if (!mcp251x_enable_dma) {
1146 priv->spi_tx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,
1148 if (!priv->spi_tx_buf) {
1152 priv->spi_rx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,
1154 if (!priv->spi_rx_buf) {
1160 SET_NETDEV_DEV(net, &spi->dev);
1162 /* Here is OK to not lock the MCP, no one knows about it yet */
1163 ret = mcp251x_hw_probe(spi);
1166 dev_err(&spi->dev, "Cannot initialize MCP%x. Wrong wiring?\n", priv->model);
1170 mcp251x_hw_sleep(spi);
1172 ret = register_candev(net);
1176 devm_can_led_init(net);
1178 netdev_info(net, "MCP%x successfully initialized.\n", priv->model);
1182 mcp251x_power_enable(priv->power, 0);
1186 clk_disable_unprepare(clk);
1191 dev_err(&spi->dev, "Probe failed, err=%d\n", -ret);
1195 static int mcp251x_can_remove(struct spi_device *spi)
1197 struct mcp251x_priv *priv = spi_get_drvdata(spi);
1198 struct net_device *net = priv->net;
1200 unregister_candev(net);
1202 mcp251x_power_enable(priv->power, 0);
1204 if (!IS_ERR(priv->clk))
1205 clk_disable_unprepare(priv->clk);
1212 static int __maybe_unused mcp251x_can_suspend(struct device *dev)
1214 struct spi_device *spi = to_spi_device(dev);
1215 struct mcp251x_priv *priv = spi_get_drvdata(spi);
1216 struct net_device *net = priv->net;
1218 priv->force_quit = 1;
1219 disable_irq(spi->irq);
1221 * Note: at this point neither IST nor workqueues are running.
1222 * open/stop cannot be called anyway so locking is not needed
1224 if (netif_running(net)) {
1225 netif_device_detach(net);
1227 mcp251x_hw_sleep(spi);
1228 mcp251x_power_enable(priv->transceiver, 0);
1229 priv->after_suspend = AFTER_SUSPEND_UP;
1231 priv->after_suspend = AFTER_SUSPEND_DOWN;
1234 if (!IS_ERR_OR_NULL(priv->power)) {
1235 regulator_disable(priv->power);
1236 priv->after_suspend |= AFTER_SUSPEND_POWER;
1242 static int __maybe_unused mcp251x_can_resume(struct device *dev)
1244 struct spi_device *spi = to_spi_device(dev);
1245 struct mcp251x_priv *priv = spi_get_drvdata(spi);
1247 if (priv->after_suspend & AFTER_SUSPEND_POWER)
1248 mcp251x_power_enable(priv->power, 1);
1250 if (priv->after_suspend & AFTER_SUSPEND_UP) {
1251 mcp251x_power_enable(priv->transceiver, 1);
1252 queue_work(priv->wq, &priv->restart_work);
1254 priv->after_suspend = 0;
1257 priv->force_quit = 0;
1258 enable_irq(spi->irq);
1262 static SIMPLE_DEV_PM_OPS(mcp251x_can_pm_ops, mcp251x_can_suspend,
1263 mcp251x_can_resume);
1265 static struct spi_driver mcp251x_can_driver = {
1267 .name = DEVICE_NAME,
1268 .of_match_table = mcp251x_of_match,
1269 .pm = &mcp251x_can_pm_ops,
1271 .id_table = mcp251x_id_table,
1272 .probe = mcp251x_can_probe,
1273 .remove = mcp251x_can_remove,
1275 module_spi_driver(mcp251x_can_driver);
1277 MODULE_AUTHOR("Chris Elston <celston@katalix.com>, "
1278 "Christian Pellegrin <chripell@evolware.org>");
1279 MODULE_DESCRIPTION("Microchip 251x/25625 CAN driver");
1280 MODULE_LICENSE("GPL v2");