2 * flexcan.c - FLEXCAN CAN controller driver
4 * Copyright (c) 2005-2006 Varma Electronics Oy
5 * Copyright (c) 2009 Sascha Hauer, Pengutronix
6 * Copyright (c) 2010 Marc Kleine-Budde, Pengutronix
8 * Based on code originally by Andrey Volkov <avolkov@varma-el.com>
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License as
13 * published by the Free Software Foundation version 2.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
22 #include <linux/netdevice.h>
23 #include <linux/can.h>
24 #include <linux/can/dev.h>
25 #include <linux/can/error.h>
26 #include <linux/can/led.h>
27 #include <linux/clk.h>
28 #include <linux/delay.h>
29 #include <linux/if_arp.h>
30 #include <linux/if_ether.h>
31 #include <linux/interrupt.h>
33 #include <linux/kernel.h>
34 #include <linux/list.h>
35 #include <linux/module.h>
37 #include <linux/of_device.h>
38 #include <linux/platform_device.h>
39 #include <linux/regulator/consumer.h>
41 #define DRV_NAME "flexcan"
43 /* 8 for RX fifo and 2 error handling */
44 #define FLEXCAN_NAPI_WEIGHT (8 + 2)
46 /* FLEXCAN module configuration register (CANMCR) bits */
47 #define FLEXCAN_MCR_MDIS BIT(31)
48 #define FLEXCAN_MCR_FRZ BIT(30)
49 #define FLEXCAN_MCR_FEN BIT(29)
50 #define FLEXCAN_MCR_HALT BIT(28)
51 #define FLEXCAN_MCR_NOT_RDY BIT(27)
52 #define FLEXCAN_MCR_WAK_MSK BIT(26)
53 #define FLEXCAN_MCR_SOFTRST BIT(25)
54 #define FLEXCAN_MCR_FRZ_ACK BIT(24)
55 #define FLEXCAN_MCR_SUPV BIT(23)
56 #define FLEXCAN_MCR_SLF_WAK BIT(22)
57 #define FLEXCAN_MCR_WRN_EN BIT(21)
58 #define FLEXCAN_MCR_LPM_ACK BIT(20)
59 #define FLEXCAN_MCR_WAK_SRC BIT(19)
60 #define FLEXCAN_MCR_DOZE BIT(18)
61 #define FLEXCAN_MCR_SRX_DIS BIT(17)
62 #define FLEXCAN_MCR_BCC BIT(16)
63 #define FLEXCAN_MCR_LPRIO_EN BIT(13)
64 #define FLEXCAN_MCR_AEN BIT(12)
65 #define FLEXCAN_MCR_MAXMB(x) ((x) & 0xf)
66 #define FLEXCAN_MCR_IDAM_A (0 << 8)
67 #define FLEXCAN_MCR_IDAM_B (1 << 8)
68 #define FLEXCAN_MCR_IDAM_C (2 << 8)
69 #define FLEXCAN_MCR_IDAM_D (3 << 8)
71 /* FLEXCAN control register (CANCTRL) bits */
72 #define FLEXCAN_CTRL_PRESDIV(x) (((x) & 0xff) << 24)
73 #define FLEXCAN_CTRL_RJW(x) (((x) & 0x03) << 22)
74 #define FLEXCAN_CTRL_PSEG1(x) (((x) & 0x07) << 19)
75 #define FLEXCAN_CTRL_PSEG2(x) (((x) & 0x07) << 16)
76 #define FLEXCAN_CTRL_BOFF_MSK BIT(15)
77 #define FLEXCAN_CTRL_ERR_MSK BIT(14)
78 #define FLEXCAN_CTRL_CLK_SRC BIT(13)
79 #define FLEXCAN_CTRL_LPB BIT(12)
80 #define FLEXCAN_CTRL_TWRN_MSK BIT(11)
81 #define FLEXCAN_CTRL_RWRN_MSK BIT(10)
82 #define FLEXCAN_CTRL_SMP BIT(7)
83 #define FLEXCAN_CTRL_BOFF_REC BIT(6)
84 #define FLEXCAN_CTRL_TSYN BIT(5)
85 #define FLEXCAN_CTRL_LBUF BIT(4)
86 #define FLEXCAN_CTRL_LOM BIT(3)
87 #define FLEXCAN_CTRL_PROPSEG(x) ((x) & 0x07)
88 #define FLEXCAN_CTRL_ERR_BUS (FLEXCAN_CTRL_ERR_MSK)
89 #define FLEXCAN_CTRL_ERR_STATE \
90 (FLEXCAN_CTRL_TWRN_MSK | FLEXCAN_CTRL_RWRN_MSK | \
91 FLEXCAN_CTRL_BOFF_MSK)
92 #define FLEXCAN_CTRL_ERR_ALL \
93 (FLEXCAN_CTRL_ERR_BUS | FLEXCAN_CTRL_ERR_STATE)
95 /* FLEXCAN error and status register (ESR) bits */
96 #define FLEXCAN_ESR_TWRN_INT BIT(17)
97 #define FLEXCAN_ESR_RWRN_INT BIT(16)
98 #define FLEXCAN_ESR_BIT1_ERR BIT(15)
99 #define FLEXCAN_ESR_BIT0_ERR BIT(14)
100 #define FLEXCAN_ESR_ACK_ERR BIT(13)
101 #define FLEXCAN_ESR_CRC_ERR BIT(12)
102 #define FLEXCAN_ESR_FRM_ERR BIT(11)
103 #define FLEXCAN_ESR_STF_ERR BIT(10)
104 #define FLEXCAN_ESR_TX_WRN BIT(9)
105 #define FLEXCAN_ESR_RX_WRN BIT(8)
106 #define FLEXCAN_ESR_IDLE BIT(7)
107 #define FLEXCAN_ESR_TXRX BIT(6)
108 #define FLEXCAN_EST_FLT_CONF_SHIFT (4)
109 #define FLEXCAN_ESR_FLT_CONF_MASK (0x3 << FLEXCAN_EST_FLT_CONF_SHIFT)
110 #define FLEXCAN_ESR_FLT_CONF_ACTIVE (0x0 << FLEXCAN_EST_FLT_CONF_SHIFT)
111 #define FLEXCAN_ESR_FLT_CONF_PASSIVE (0x1 << FLEXCAN_EST_FLT_CONF_SHIFT)
112 #define FLEXCAN_ESR_BOFF_INT BIT(2)
113 #define FLEXCAN_ESR_ERR_INT BIT(1)
114 #define FLEXCAN_ESR_WAK_INT BIT(0)
115 #define FLEXCAN_ESR_ERR_BUS \
116 (FLEXCAN_ESR_BIT1_ERR | FLEXCAN_ESR_BIT0_ERR | \
117 FLEXCAN_ESR_ACK_ERR | FLEXCAN_ESR_CRC_ERR | \
118 FLEXCAN_ESR_FRM_ERR | FLEXCAN_ESR_STF_ERR)
119 #define FLEXCAN_ESR_ERR_STATE \
120 (FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | FLEXCAN_ESR_BOFF_INT)
121 #define FLEXCAN_ESR_ERR_ALL \
122 (FLEXCAN_ESR_ERR_BUS | FLEXCAN_ESR_ERR_STATE)
123 #define FLEXCAN_ESR_ALL_INT \
124 (FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | \
125 FLEXCAN_ESR_BOFF_INT | FLEXCAN_ESR_ERR_INT)
127 /* FLEXCAN interrupt flag register (IFLAG) bits */
128 #define FLEXCAN_TX_BUF_ID 8
129 #define FLEXCAN_IFLAG_BUF(x) BIT(x)
130 #define FLEXCAN_IFLAG_RX_FIFO_OVERFLOW BIT(7)
131 #define FLEXCAN_IFLAG_RX_FIFO_WARN BIT(6)
132 #define FLEXCAN_IFLAG_RX_FIFO_AVAILABLE BIT(5)
133 #define FLEXCAN_IFLAG_DEFAULT \
134 (FLEXCAN_IFLAG_RX_FIFO_OVERFLOW | FLEXCAN_IFLAG_RX_FIFO_AVAILABLE | \
135 FLEXCAN_IFLAG_BUF(FLEXCAN_TX_BUF_ID))
137 /* FLEXCAN message buffers */
138 #define FLEXCAN_MB_CNT_CODE(x) (((x) & 0xf) << 24)
139 #define FLEXCAN_MB_CNT_SRR BIT(22)
140 #define FLEXCAN_MB_CNT_IDE BIT(21)
141 #define FLEXCAN_MB_CNT_RTR BIT(20)
142 #define FLEXCAN_MB_CNT_LENGTH(x) (((x) & 0xf) << 16)
143 #define FLEXCAN_MB_CNT_TIMESTAMP(x) ((x) & 0xffff)
145 #define FLEXCAN_MB_CODE_MASK (0xf0ffffff)
148 * FLEXCAN hardware feature flags
150 * Below is some version info we got:
151 * SOC Version IP-Version Glitch- [TR]WRN_INT
153 * MX25 FlexCAN2 03.00.00.00 no no
154 * MX28 FlexCAN2 03.00.04.00 yes yes
155 * MX35 FlexCAN2 03.00.00.00 no no
156 * MX53 FlexCAN2 03.00.00.00 yes no
157 * MX6s FlexCAN3 10.00.12.00 yes yes
159 * Some SOCs do not have the RX_WARN & TX_WARN interrupt line connected.
161 #define FLEXCAN_HAS_V10_FEATURES BIT(1) /* For core version >= 10 */
162 #define FLEXCAN_HAS_BROKEN_ERR_STATE BIT(2) /* [TR]WRN_INT not connected */
164 /* Structure of the message buffer */
171 /* Structure of the hardware registers */
172 struct flexcan_regs {
175 u32 timer; /* 0x08 */
176 u32 _reserved1; /* 0x0c */
177 u32 rxgmask; /* 0x10 */
178 u32 rx14mask; /* 0x14 */
179 u32 rx15mask; /* 0x18 */
182 u32 imask2; /* 0x24 */
183 u32 imask1; /* 0x28 */
184 u32 iflag2; /* 0x2c */
185 u32 iflag1; /* 0x30 */
188 u32 imeur; /* 0x3c */
191 u32 rxfgmask; /* 0x48 */
192 u32 rxfir; /* 0x4c */
194 struct flexcan_mb cantxfg[64];
197 struct flexcan_devtype_data {
198 u32 features; /* hardware controller features */
201 struct flexcan_priv {
203 struct net_device *dev;
204 struct napi_struct napi;
208 u32 reg_ctrl_default;
212 struct flexcan_platform_data *pdata;
213 const struct flexcan_devtype_data *devtype_data;
214 struct regulator *reg_xceiver;
217 static struct flexcan_devtype_data fsl_p1010_devtype_data = {
218 .features = FLEXCAN_HAS_BROKEN_ERR_STATE,
220 static struct flexcan_devtype_data fsl_imx28_devtype_data;
221 static struct flexcan_devtype_data fsl_imx6q_devtype_data = {
222 .features = FLEXCAN_HAS_V10_FEATURES,
225 static const struct can_bittiming_const flexcan_bittiming_const = {
238 * Abstract off the read/write for arm versus ppc.
240 #if defined(__BIG_ENDIAN)
241 static inline u32 flexcan_read(void __iomem *addr)
243 return in_be32(addr);
246 static inline void flexcan_write(u32 val, void __iomem *addr)
251 static inline u32 flexcan_read(void __iomem *addr)
256 static inline void flexcan_write(u32 val, void __iomem *addr)
262 static inline int flexcan_has_and_handle_berr(const struct flexcan_priv *priv,
265 return (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) &&
266 (reg_esr & FLEXCAN_ESR_ERR_BUS);
269 static inline void flexcan_chip_enable(struct flexcan_priv *priv)
271 struct flexcan_regs __iomem *regs = priv->base;
274 reg = flexcan_read(®s->mcr);
275 reg &= ~FLEXCAN_MCR_MDIS;
276 flexcan_write(reg, ®s->mcr);
281 static inline void flexcan_chip_disable(struct flexcan_priv *priv)
283 struct flexcan_regs __iomem *regs = priv->base;
286 reg = flexcan_read(®s->mcr);
287 reg |= FLEXCAN_MCR_MDIS;
288 flexcan_write(reg, ®s->mcr);
291 static int flexcan_get_berr_counter(const struct net_device *dev,
292 struct can_berr_counter *bec)
294 const struct flexcan_priv *priv = netdev_priv(dev);
295 struct flexcan_regs __iomem *regs = priv->base;
296 u32 reg = flexcan_read(®s->ecr);
298 bec->txerr = (reg >> 0) & 0xff;
299 bec->rxerr = (reg >> 8) & 0xff;
304 static int flexcan_start_xmit(struct sk_buff *skb, struct net_device *dev)
306 const struct flexcan_priv *priv = netdev_priv(dev);
307 struct flexcan_regs __iomem *regs = priv->base;
308 struct can_frame *cf = (struct can_frame *)skb->data;
310 u32 ctrl = FLEXCAN_MB_CNT_CODE(0xc) | (cf->can_dlc << 16);
312 if (can_dropped_invalid_skb(dev, skb))
315 netif_stop_queue(dev);
317 if (cf->can_id & CAN_EFF_FLAG) {
318 can_id = cf->can_id & CAN_EFF_MASK;
319 ctrl |= FLEXCAN_MB_CNT_IDE | FLEXCAN_MB_CNT_SRR;
321 can_id = (cf->can_id & CAN_SFF_MASK) << 18;
324 if (cf->can_id & CAN_RTR_FLAG)
325 ctrl |= FLEXCAN_MB_CNT_RTR;
327 if (cf->can_dlc > 0) {
328 u32 data = be32_to_cpup((__be32 *)&cf->data[0]);
329 flexcan_write(data, ®s->cantxfg[FLEXCAN_TX_BUF_ID].data[0]);
331 if (cf->can_dlc > 3) {
332 u32 data = be32_to_cpup((__be32 *)&cf->data[4]);
333 flexcan_write(data, ®s->cantxfg[FLEXCAN_TX_BUF_ID].data[1]);
336 can_put_echo_skb(skb, dev, 0);
338 flexcan_write(can_id, ®s->cantxfg[FLEXCAN_TX_BUF_ID].can_id);
339 flexcan_write(ctrl, ®s->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl);
344 static void do_bus_err(struct net_device *dev,
345 struct can_frame *cf, u32 reg_esr)
347 struct flexcan_priv *priv = netdev_priv(dev);
348 int rx_errors = 0, tx_errors = 0;
350 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
352 if (reg_esr & FLEXCAN_ESR_BIT1_ERR) {
353 netdev_dbg(dev, "BIT1_ERR irq\n");
354 cf->data[2] |= CAN_ERR_PROT_BIT1;
357 if (reg_esr & FLEXCAN_ESR_BIT0_ERR) {
358 netdev_dbg(dev, "BIT0_ERR irq\n");
359 cf->data[2] |= CAN_ERR_PROT_BIT0;
362 if (reg_esr & FLEXCAN_ESR_ACK_ERR) {
363 netdev_dbg(dev, "ACK_ERR irq\n");
364 cf->can_id |= CAN_ERR_ACK;
365 cf->data[3] |= CAN_ERR_PROT_LOC_ACK;
368 if (reg_esr & FLEXCAN_ESR_CRC_ERR) {
369 netdev_dbg(dev, "CRC_ERR irq\n");
370 cf->data[2] |= CAN_ERR_PROT_BIT;
371 cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
374 if (reg_esr & FLEXCAN_ESR_FRM_ERR) {
375 netdev_dbg(dev, "FRM_ERR irq\n");
376 cf->data[2] |= CAN_ERR_PROT_FORM;
379 if (reg_esr & FLEXCAN_ESR_STF_ERR) {
380 netdev_dbg(dev, "STF_ERR irq\n");
381 cf->data[2] |= CAN_ERR_PROT_STUFF;
385 priv->can.can_stats.bus_error++;
387 dev->stats.rx_errors++;
389 dev->stats.tx_errors++;
392 static int flexcan_poll_bus_err(struct net_device *dev, u32 reg_esr)
395 struct can_frame *cf;
397 skb = alloc_can_err_skb(dev, &cf);
401 do_bus_err(dev, cf, reg_esr);
402 netif_receive_skb(skb);
404 dev->stats.rx_packets++;
405 dev->stats.rx_bytes += cf->can_dlc;
410 static void do_state(struct net_device *dev,
411 struct can_frame *cf, enum can_state new_state)
413 struct flexcan_priv *priv = netdev_priv(dev);
414 struct can_berr_counter bec;
416 flexcan_get_berr_counter(dev, &bec);
418 switch (priv->can.state) {
419 case CAN_STATE_ERROR_ACTIVE:
422 * to : ERROR_WARNING, ERROR_PASSIVE, BUS_OFF
423 * => : there was a warning int
425 if (new_state >= CAN_STATE_ERROR_WARNING &&
426 new_state <= CAN_STATE_BUS_OFF) {
427 netdev_dbg(dev, "Error Warning IRQ\n");
428 priv->can.can_stats.error_warning++;
430 cf->can_id |= CAN_ERR_CRTL;
431 cf->data[1] = (bec.txerr > bec.rxerr) ?
432 CAN_ERR_CRTL_TX_WARNING :
433 CAN_ERR_CRTL_RX_WARNING;
435 case CAN_STATE_ERROR_WARNING: /* fallthrough */
437 * from: ERROR_ACTIVE, ERROR_WARNING
438 * to : ERROR_PASSIVE, BUS_OFF
439 * => : error passive int
441 if (new_state >= CAN_STATE_ERROR_PASSIVE &&
442 new_state <= CAN_STATE_BUS_OFF) {
443 netdev_dbg(dev, "Error Passive IRQ\n");
444 priv->can.can_stats.error_passive++;
446 cf->can_id |= CAN_ERR_CRTL;
447 cf->data[1] = (bec.txerr > bec.rxerr) ?
448 CAN_ERR_CRTL_TX_PASSIVE :
449 CAN_ERR_CRTL_RX_PASSIVE;
452 case CAN_STATE_BUS_OFF:
453 netdev_err(dev, "BUG! "
454 "hardware recovered automatically from BUS_OFF\n");
460 /* process state changes depending on the new state */
462 case CAN_STATE_ERROR_ACTIVE:
463 netdev_dbg(dev, "Error Active\n");
464 cf->can_id |= CAN_ERR_PROT;
465 cf->data[2] = CAN_ERR_PROT_ACTIVE;
467 case CAN_STATE_BUS_OFF:
468 cf->can_id |= CAN_ERR_BUSOFF;
476 static int flexcan_poll_state(struct net_device *dev, u32 reg_esr)
478 struct flexcan_priv *priv = netdev_priv(dev);
480 struct can_frame *cf;
481 enum can_state new_state;
484 flt = reg_esr & FLEXCAN_ESR_FLT_CONF_MASK;
485 if (likely(flt == FLEXCAN_ESR_FLT_CONF_ACTIVE)) {
486 if (likely(!(reg_esr & (FLEXCAN_ESR_TX_WRN |
487 FLEXCAN_ESR_RX_WRN))))
488 new_state = CAN_STATE_ERROR_ACTIVE;
490 new_state = CAN_STATE_ERROR_WARNING;
491 } else if (unlikely(flt == FLEXCAN_ESR_FLT_CONF_PASSIVE))
492 new_state = CAN_STATE_ERROR_PASSIVE;
494 new_state = CAN_STATE_BUS_OFF;
496 /* state hasn't changed */
497 if (likely(new_state == priv->can.state))
500 skb = alloc_can_err_skb(dev, &cf);
504 do_state(dev, cf, new_state);
505 priv->can.state = new_state;
506 netif_receive_skb(skb);
508 dev->stats.rx_packets++;
509 dev->stats.rx_bytes += cf->can_dlc;
514 static void flexcan_read_fifo(const struct net_device *dev,
515 struct can_frame *cf)
517 const struct flexcan_priv *priv = netdev_priv(dev);
518 struct flexcan_regs __iomem *regs = priv->base;
519 struct flexcan_mb __iomem *mb = ®s->cantxfg[0];
520 u32 reg_ctrl, reg_id;
522 reg_ctrl = flexcan_read(&mb->can_ctrl);
523 reg_id = flexcan_read(&mb->can_id);
524 if (reg_ctrl & FLEXCAN_MB_CNT_IDE)
525 cf->can_id = ((reg_id >> 0) & CAN_EFF_MASK) | CAN_EFF_FLAG;
527 cf->can_id = (reg_id >> 18) & CAN_SFF_MASK;
529 if (reg_ctrl & FLEXCAN_MB_CNT_RTR)
530 cf->can_id |= CAN_RTR_FLAG;
531 cf->can_dlc = get_can_dlc((reg_ctrl >> 16) & 0xf);
533 *(__be32 *)(cf->data + 0) = cpu_to_be32(flexcan_read(&mb->data[0]));
534 *(__be32 *)(cf->data + 4) = cpu_to_be32(flexcan_read(&mb->data[1]));
537 flexcan_write(FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, ®s->iflag1);
538 flexcan_read(®s->timer);
541 static int flexcan_read_frame(struct net_device *dev)
543 struct net_device_stats *stats = &dev->stats;
544 struct can_frame *cf;
547 skb = alloc_can_skb(dev, &cf);
548 if (unlikely(!skb)) {
553 flexcan_read_fifo(dev, cf);
554 netif_receive_skb(skb);
557 stats->rx_bytes += cf->can_dlc;
559 can_led_event(dev, CAN_LED_EVENT_RX);
564 static int flexcan_poll(struct napi_struct *napi, int quota)
566 struct net_device *dev = napi->dev;
567 const struct flexcan_priv *priv = netdev_priv(dev);
568 struct flexcan_regs __iomem *regs = priv->base;
569 u32 reg_iflag1, reg_esr;
573 * The error bits are cleared on read,
574 * use saved value from irq handler.
576 reg_esr = flexcan_read(®s->esr) | priv->reg_esr;
578 /* handle state changes */
579 work_done += flexcan_poll_state(dev, reg_esr);
582 reg_iflag1 = flexcan_read(®s->iflag1);
583 while (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE &&
585 work_done += flexcan_read_frame(dev);
586 reg_iflag1 = flexcan_read(®s->iflag1);
589 /* report bus errors */
590 if (flexcan_has_and_handle_berr(priv, reg_esr) && work_done < quota)
591 work_done += flexcan_poll_bus_err(dev, reg_esr);
593 if (work_done < quota) {
596 flexcan_write(FLEXCAN_IFLAG_DEFAULT, ®s->imask1);
597 flexcan_write(priv->reg_ctrl_default, ®s->ctrl);
603 static irqreturn_t flexcan_irq(int irq, void *dev_id)
605 struct net_device *dev = dev_id;
606 struct net_device_stats *stats = &dev->stats;
607 struct flexcan_priv *priv = netdev_priv(dev);
608 struct flexcan_regs __iomem *regs = priv->base;
609 u32 reg_iflag1, reg_esr;
611 reg_iflag1 = flexcan_read(®s->iflag1);
612 reg_esr = flexcan_read(®s->esr);
613 /* ACK all bus error and state change IRQ sources */
614 if (reg_esr & FLEXCAN_ESR_ALL_INT)
615 flexcan_write(reg_esr & FLEXCAN_ESR_ALL_INT, ®s->esr);
618 * schedule NAPI in case of:
621 * - bus error IRQ and bus error reporting is activated
623 if ((reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE) ||
624 (reg_esr & FLEXCAN_ESR_ERR_STATE) ||
625 flexcan_has_and_handle_berr(priv, reg_esr)) {
627 * The error bits are cleared on read,
628 * save them for later use.
630 priv->reg_esr = reg_esr & FLEXCAN_ESR_ERR_BUS;
631 flexcan_write(FLEXCAN_IFLAG_DEFAULT &
632 ~FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, ®s->imask1);
633 flexcan_write(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_ALL,
635 napi_schedule(&priv->napi);
639 if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_OVERFLOW) {
640 flexcan_write(FLEXCAN_IFLAG_RX_FIFO_OVERFLOW, ®s->iflag1);
641 dev->stats.rx_over_errors++;
642 dev->stats.rx_errors++;
645 /* transmission complete interrupt */
646 if (reg_iflag1 & (1 << FLEXCAN_TX_BUF_ID)) {
647 stats->tx_bytes += can_get_echo_skb(dev, 0);
649 can_led_event(dev, CAN_LED_EVENT_TX);
650 flexcan_write((1 << FLEXCAN_TX_BUF_ID), ®s->iflag1);
651 netif_wake_queue(dev);
657 static void flexcan_set_bittiming(struct net_device *dev)
659 const struct flexcan_priv *priv = netdev_priv(dev);
660 const struct can_bittiming *bt = &priv->can.bittiming;
661 struct flexcan_regs __iomem *regs = priv->base;
664 reg = flexcan_read(®s->ctrl);
665 reg &= ~(FLEXCAN_CTRL_PRESDIV(0xff) |
666 FLEXCAN_CTRL_RJW(0x3) |
667 FLEXCAN_CTRL_PSEG1(0x7) |
668 FLEXCAN_CTRL_PSEG2(0x7) |
669 FLEXCAN_CTRL_PROPSEG(0x7) |
674 reg |= FLEXCAN_CTRL_PRESDIV(bt->brp - 1) |
675 FLEXCAN_CTRL_PSEG1(bt->phase_seg1 - 1) |
676 FLEXCAN_CTRL_PSEG2(bt->phase_seg2 - 1) |
677 FLEXCAN_CTRL_RJW(bt->sjw - 1) |
678 FLEXCAN_CTRL_PROPSEG(bt->prop_seg - 1);
680 if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
681 reg |= FLEXCAN_CTRL_LPB;
682 if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
683 reg |= FLEXCAN_CTRL_LOM;
684 if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
685 reg |= FLEXCAN_CTRL_SMP;
687 netdev_info(dev, "writing ctrl=0x%08x\n", reg);
688 flexcan_write(reg, ®s->ctrl);
690 /* print chip status */
691 netdev_dbg(dev, "%s: mcr=0x%08x ctrl=0x%08x\n", __func__,
692 flexcan_read(®s->mcr), flexcan_read(®s->ctrl));
698 * this functions is entered with clocks enabled
701 static int flexcan_chip_start(struct net_device *dev)
703 struct flexcan_priv *priv = netdev_priv(dev);
704 struct flexcan_regs __iomem *regs = priv->base;
707 u32 reg_mcr, reg_ctrl;
710 flexcan_chip_enable(priv);
713 flexcan_write(FLEXCAN_MCR_SOFTRST, ®s->mcr);
716 reg_mcr = flexcan_read(®s->mcr);
717 if (reg_mcr & FLEXCAN_MCR_SOFTRST) {
718 netdev_err(dev, "Failed to softreset can module (mcr=0x%08x)\n",
724 flexcan_set_bittiming(dev);
732 * only supervisor access
738 reg_mcr = flexcan_read(®s->mcr);
739 reg_mcr |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_FEN | FLEXCAN_MCR_HALT |
740 FLEXCAN_MCR_SUPV | FLEXCAN_MCR_WRN_EN |
741 FLEXCAN_MCR_IDAM_C | FLEXCAN_MCR_SRX_DIS;
742 netdev_dbg(dev, "%s: writing mcr=0x%08x", __func__, reg_mcr);
743 flexcan_write(reg_mcr, ®s->mcr);
748 * disable timer sync feature
750 * disable auto busoff recovery
751 * transmit lowest buffer first
753 * enable tx and rx warning interrupt
754 * enable bus off interrupt
755 * (== FLEXCAN_CTRL_ERR_STATE)
757 reg_ctrl = flexcan_read(®s->ctrl);
758 reg_ctrl &= ~FLEXCAN_CTRL_TSYN;
759 reg_ctrl |= FLEXCAN_CTRL_BOFF_REC | FLEXCAN_CTRL_LBUF |
760 FLEXCAN_CTRL_ERR_STATE;
762 * enable the "error interrupt" (FLEXCAN_CTRL_ERR_MSK),
763 * on most Flexcan cores, too. Otherwise we don't get
764 * any error warning or passive interrupts.
766 if (priv->devtype_data->features & FLEXCAN_HAS_BROKEN_ERR_STATE ||
767 priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
768 reg_ctrl |= FLEXCAN_CTRL_ERR_MSK;
770 /* save for later use */
771 priv->reg_ctrl_default = reg_ctrl;
772 netdev_dbg(dev, "%s: writing ctrl=0x%08x", __func__, reg_ctrl);
773 flexcan_write(reg_ctrl, ®s->ctrl);
775 for (i = 0; i < ARRAY_SIZE(regs->cantxfg); i++) {
776 flexcan_write(0, ®s->cantxfg[i].can_ctrl);
777 flexcan_write(0, ®s->cantxfg[i].can_id);
778 flexcan_write(0, ®s->cantxfg[i].data[0]);
779 flexcan_write(0, ®s->cantxfg[i].data[1]);
781 /* put MB into rx queue */
782 flexcan_write(FLEXCAN_MB_CNT_CODE(0x4),
783 ®s->cantxfg[i].can_ctrl);
786 /* acceptance mask/acceptance code (accept everything) */
787 flexcan_write(0x0, ®s->rxgmask);
788 flexcan_write(0x0, ®s->rx14mask);
789 flexcan_write(0x0, ®s->rx15mask);
791 if (priv->devtype_data->features & FLEXCAN_HAS_V10_FEATURES)
792 flexcan_write(0x0, ®s->rxfgmask);
794 if (priv->reg_xceiver) {
795 err = regulator_enable(priv->reg_xceiver);
800 /* synchronize with the can bus */
801 reg_mcr = flexcan_read(®s->mcr);
802 reg_mcr &= ~FLEXCAN_MCR_HALT;
803 flexcan_write(reg_mcr, ®s->mcr);
805 priv->can.state = CAN_STATE_ERROR_ACTIVE;
807 /* enable FIFO interrupts */
808 flexcan_write(FLEXCAN_IFLAG_DEFAULT, ®s->imask1);
810 /* print chip status */
811 netdev_dbg(dev, "%s: reading mcr=0x%08x ctrl=0x%08x\n", __func__,
812 flexcan_read(®s->mcr), flexcan_read(®s->ctrl));
817 flexcan_chip_disable(priv);
824 * this functions is entered with clocks enabled
827 static void flexcan_chip_stop(struct net_device *dev)
829 struct flexcan_priv *priv = netdev_priv(dev);
830 struct flexcan_regs __iomem *regs = priv->base;
833 /* Disable all interrupts */
834 flexcan_write(0, ®s->imask1);
836 /* Disable + halt module */
837 reg = flexcan_read(®s->mcr);
838 reg |= FLEXCAN_MCR_MDIS | FLEXCAN_MCR_HALT;
839 flexcan_write(reg, ®s->mcr);
841 if (priv->reg_xceiver)
842 regulator_disable(priv->reg_xceiver);
843 priv->can.state = CAN_STATE_STOPPED;
848 static int flexcan_open(struct net_device *dev)
850 struct flexcan_priv *priv = netdev_priv(dev);
853 err = clk_prepare_enable(priv->clk_ipg);
857 err = clk_prepare_enable(priv->clk_per);
859 goto out_disable_ipg;
861 err = open_candev(dev);
863 goto out_disable_per;
865 err = request_irq(dev->irq, flexcan_irq, IRQF_SHARED, dev->name, dev);
869 /* start chip and queuing */
870 err = flexcan_chip_start(dev);
874 can_led_event(dev, CAN_LED_EVENT_OPEN);
876 napi_enable(&priv->napi);
877 netif_start_queue(dev);
884 clk_disable_unprepare(priv->clk_per);
886 clk_disable_unprepare(priv->clk_ipg);
891 static int flexcan_close(struct net_device *dev)
893 struct flexcan_priv *priv = netdev_priv(dev);
895 netif_stop_queue(dev);
896 napi_disable(&priv->napi);
897 flexcan_chip_stop(dev);
899 free_irq(dev->irq, dev);
900 clk_disable_unprepare(priv->clk_per);
901 clk_disable_unprepare(priv->clk_ipg);
905 can_led_event(dev, CAN_LED_EVENT_STOP);
910 static int flexcan_set_mode(struct net_device *dev, enum can_mode mode)
916 err = flexcan_chip_start(dev);
920 netif_wake_queue(dev);
930 static const struct net_device_ops flexcan_netdev_ops = {
931 .ndo_open = flexcan_open,
932 .ndo_stop = flexcan_close,
933 .ndo_start_xmit = flexcan_start_xmit,
936 static int register_flexcandev(struct net_device *dev)
938 struct flexcan_priv *priv = netdev_priv(dev);
939 struct flexcan_regs __iomem *regs = priv->base;
942 err = clk_prepare_enable(priv->clk_ipg);
946 err = clk_prepare_enable(priv->clk_per);
948 goto out_disable_ipg;
950 /* select "bus clock", chip must be disabled */
951 flexcan_chip_disable(priv);
952 reg = flexcan_read(®s->ctrl);
953 reg |= FLEXCAN_CTRL_CLK_SRC;
954 flexcan_write(reg, ®s->ctrl);
956 flexcan_chip_enable(priv);
958 /* set freeze, halt and activate FIFO, restrict register access */
959 reg = flexcan_read(®s->mcr);
960 reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT |
961 FLEXCAN_MCR_FEN | FLEXCAN_MCR_SUPV;
962 flexcan_write(reg, ®s->mcr);
965 * Currently we only support newer versions of this core
966 * featuring a RX FIFO. Older cores found on some Coldfire
967 * derivates are not yet supported.
969 reg = flexcan_read(®s->mcr);
970 if (!(reg & FLEXCAN_MCR_FEN)) {
971 netdev_err(dev, "Could not enable RX FIFO, unsupported core\n");
973 goto out_disable_per;
976 err = register_candev(dev);
979 /* disable core and turn off clocks */
980 flexcan_chip_disable(priv);
981 clk_disable_unprepare(priv->clk_per);
983 clk_disable_unprepare(priv->clk_ipg);
988 static void unregister_flexcandev(struct net_device *dev)
990 unregister_candev(dev);
993 static const struct of_device_id flexcan_of_match[] = {
994 { .compatible = "fsl,p1010-flexcan", .data = &fsl_p1010_devtype_data, },
995 { .compatible = "fsl,imx28-flexcan", .data = &fsl_imx28_devtype_data, },
996 { .compatible = "fsl,imx6q-flexcan", .data = &fsl_imx6q_devtype_data, },
999 MODULE_DEVICE_TABLE(of, flexcan_of_match);
1001 static const struct platform_device_id flexcan_id_table[] = {
1002 { .name = "flexcan", .driver_data = (kernel_ulong_t)&fsl_p1010_devtype_data, },
1005 MODULE_DEVICE_TABLE(platform, flexcan_id_table);
1007 static int flexcan_probe(struct platform_device *pdev)
1009 const struct of_device_id *of_id;
1010 const struct flexcan_devtype_data *devtype_data;
1011 struct net_device *dev;
1012 struct flexcan_priv *priv;
1013 struct resource *mem;
1014 struct clk *clk_ipg = NULL, *clk_per = NULL;
1019 if (pdev->dev.of_node)
1020 of_property_read_u32(pdev->dev.of_node,
1021 "clock-frequency", &clock_freq);
1024 clk_ipg = devm_clk_get(&pdev->dev, "ipg");
1025 if (IS_ERR(clk_ipg)) {
1026 dev_err(&pdev->dev, "no ipg clock defined\n");
1027 return PTR_ERR(clk_ipg);
1029 clock_freq = clk_get_rate(clk_ipg);
1031 clk_per = devm_clk_get(&pdev->dev, "per");
1032 if (IS_ERR(clk_per)) {
1033 dev_err(&pdev->dev, "no per clock defined\n");
1034 return PTR_ERR(clk_per);
1038 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1039 irq = platform_get_irq(pdev, 0);
1043 base = devm_ioremap_resource(&pdev->dev, mem);
1045 return PTR_ERR(base);
1047 of_id = of_match_device(flexcan_of_match, &pdev->dev);
1049 devtype_data = of_id->data;
1050 } else if (pdev->id_entry->driver_data) {
1051 devtype_data = (struct flexcan_devtype_data *)
1052 pdev->id_entry->driver_data;
1057 dev = alloc_candev(sizeof(struct flexcan_priv), 1);
1061 dev->netdev_ops = &flexcan_netdev_ops;
1063 dev->flags |= IFF_ECHO;
1065 priv = netdev_priv(dev);
1066 priv->can.clock.freq = clock_freq;
1067 priv->can.bittiming_const = &flexcan_bittiming_const;
1068 priv->can.do_set_mode = flexcan_set_mode;
1069 priv->can.do_get_berr_counter = flexcan_get_berr_counter;
1070 priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
1071 CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_3_SAMPLES |
1072 CAN_CTRLMODE_BERR_REPORTING;
1075 priv->clk_ipg = clk_ipg;
1076 priv->clk_per = clk_per;
1077 priv->pdata = pdev->dev.platform_data;
1078 priv->devtype_data = devtype_data;
1080 priv->reg_xceiver = devm_regulator_get(&pdev->dev, "xceiver");
1081 if (IS_ERR(priv->reg_xceiver))
1082 priv->reg_xceiver = NULL;
1084 netif_napi_add(dev, &priv->napi, flexcan_poll, FLEXCAN_NAPI_WEIGHT);
1086 platform_set_drvdata(pdev, dev);
1087 SET_NETDEV_DEV(dev, &pdev->dev);
1089 err = register_flexcandev(dev);
1091 dev_err(&pdev->dev, "registering netdev failed\n");
1092 goto failed_register;
1095 devm_can_led_init(dev);
1097 dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%d)\n",
1098 priv->base, dev->irq);
1107 static int flexcan_remove(struct platform_device *pdev)
1109 struct net_device *dev = platform_get_drvdata(pdev);
1111 unregister_flexcandev(dev);
1118 #ifdef CONFIG_PM_SLEEP
1119 static int flexcan_suspend(struct device *device)
1121 struct net_device *dev = dev_get_drvdata(device);
1122 struct flexcan_priv *priv = netdev_priv(dev);
1124 flexcan_chip_disable(priv);
1126 if (netif_running(dev)) {
1127 netif_stop_queue(dev);
1128 netif_device_detach(dev);
1130 priv->can.state = CAN_STATE_SLEEPING;
1135 static int flexcan_resume(struct device *device)
1137 struct net_device *dev = dev_get_drvdata(device);
1138 struct flexcan_priv *priv = netdev_priv(dev);
1140 priv->can.state = CAN_STATE_ERROR_ACTIVE;
1141 if (netif_running(dev)) {
1142 netif_device_attach(dev);
1143 netif_start_queue(dev);
1145 flexcan_chip_enable(priv);
1149 #endif /* CONFIG_PM_SLEEP */
1151 static SIMPLE_DEV_PM_OPS(flexcan_pm_ops, flexcan_suspend, flexcan_resume);
1153 static struct platform_driver flexcan_driver = {
1156 .owner = THIS_MODULE,
1157 .pm = &flexcan_pm_ops,
1158 .of_match_table = flexcan_of_match,
1160 .probe = flexcan_probe,
1161 .remove = flexcan_remove,
1162 .id_table = flexcan_id_table,
1165 module_platform_driver(flexcan_driver);
1167 MODULE_AUTHOR("Sascha Hauer <kernel@pengutronix.de>, "
1168 "Marc Kleine-Budde <kernel@pengutronix.de>");
1169 MODULE_LICENSE("GPL v2");
1170 MODULE_DESCRIPTION("CAN port driver for flexcan based chip");