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) & 0x1f)
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)
147 #define FLEXCAN_TIMEOUT_US (50)
150 * FLEXCAN hardware feature flags
152 * Below is some version info we got:
153 * SOC Version IP-Version Glitch- [TR]WRN_INT
155 * MX25 FlexCAN2 03.00.00.00 no no
156 * MX28 FlexCAN2 03.00.04.00 yes yes
157 * MX35 FlexCAN2 03.00.00.00 no no
158 * MX53 FlexCAN2 03.00.00.00 yes no
159 * MX6s FlexCAN3 10.00.12.00 yes yes
161 * Some SOCs do not have the RX_WARN & TX_WARN interrupt line connected.
163 #define FLEXCAN_HAS_V10_FEATURES BIT(1) /* For core version >= 10 */
164 #define FLEXCAN_HAS_BROKEN_ERR_STATE BIT(2) /* [TR]WRN_INT not connected */
166 /* Structure of the message buffer */
173 /* Structure of the hardware registers */
174 struct flexcan_regs {
177 u32 timer; /* 0x08 */
178 u32 _reserved1; /* 0x0c */
179 u32 rxgmask; /* 0x10 */
180 u32 rx14mask; /* 0x14 */
181 u32 rx15mask; /* 0x18 */
184 u32 imask2; /* 0x24 */
185 u32 imask1; /* 0x28 */
186 u32 iflag2; /* 0x2c */
187 u32 iflag1; /* 0x30 */
190 u32 imeur; /* 0x3c */
193 u32 rxfgmask; /* 0x48 */
194 u32 rxfir; /* 0x4c */
196 struct flexcan_mb cantxfg[64];
199 struct flexcan_devtype_data {
200 u32 features; /* hardware controller features */
203 struct flexcan_priv {
205 struct net_device *dev;
206 struct napi_struct napi;
210 u32 reg_ctrl_default;
214 struct flexcan_platform_data *pdata;
215 const struct flexcan_devtype_data *devtype_data;
216 struct regulator *reg_xceiver;
219 static struct flexcan_devtype_data fsl_p1010_devtype_data = {
220 .features = FLEXCAN_HAS_BROKEN_ERR_STATE,
222 static struct flexcan_devtype_data fsl_imx28_devtype_data;
223 static struct flexcan_devtype_data fsl_imx6q_devtype_data = {
224 .features = FLEXCAN_HAS_V10_FEATURES,
227 static const struct can_bittiming_const flexcan_bittiming_const = {
240 * Abstract off the read/write for arm versus ppc. This
241 * assumes that PPC uses big-endian registers and everything
242 * else uses little-endian registers, independent of CPU
245 #if defined(CONFIG_PPC)
246 static inline u32 flexcan_read(void __iomem *addr)
248 return in_be32(addr);
251 static inline void flexcan_write(u32 val, void __iomem *addr)
256 static inline u32 flexcan_read(void __iomem *addr)
261 static inline void flexcan_write(u32 val, void __iomem *addr)
267 static inline int flexcan_transceiver_enable(const struct flexcan_priv *priv)
269 if (!priv->reg_xceiver)
272 return regulator_enable(priv->reg_xceiver);
275 static inline int flexcan_transceiver_disable(const struct flexcan_priv *priv)
277 if (!priv->reg_xceiver)
280 return regulator_disable(priv->reg_xceiver);
283 static inline int flexcan_has_and_handle_berr(const struct flexcan_priv *priv,
286 return (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) &&
287 (reg_esr & FLEXCAN_ESR_ERR_BUS);
290 static int flexcan_chip_enable(struct flexcan_priv *priv)
292 struct flexcan_regs __iomem *regs = priv->base;
293 unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
296 reg = flexcan_read(®s->mcr);
297 reg &= ~FLEXCAN_MCR_MDIS;
298 flexcan_write(reg, ®s->mcr);
300 while (timeout-- && (flexcan_read(®s->mcr) & FLEXCAN_MCR_LPM_ACK))
301 usleep_range(10, 20);
303 if (flexcan_read(®s->mcr) & FLEXCAN_MCR_LPM_ACK)
309 static int flexcan_chip_disable(struct flexcan_priv *priv)
311 struct flexcan_regs __iomem *regs = priv->base;
312 unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
315 reg = flexcan_read(®s->mcr);
316 reg |= FLEXCAN_MCR_MDIS;
317 flexcan_write(reg, ®s->mcr);
319 while (timeout-- && !(flexcan_read(®s->mcr) & FLEXCAN_MCR_LPM_ACK))
320 usleep_range(10, 20);
322 if (!(flexcan_read(®s->mcr) & FLEXCAN_MCR_LPM_ACK))
328 static int flexcan_get_berr_counter(const struct net_device *dev,
329 struct can_berr_counter *bec)
331 const struct flexcan_priv *priv = netdev_priv(dev);
332 struct flexcan_regs __iomem *regs = priv->base;
333 u32 reg = flexcan_read(®s->ecr);
335 bec->txerr = (reg >> 0) & 0xff;
336 bec->rxerr = (reg >> 8) & 0xff;
341 static int flexcan_start_xmit(struct sk_buff *skb, struct net_device *dev)
343 const struct flexcan_priv *priv = netdev_priv(dev);
344 struct flexcan_regs __iomem *regs = priv->base;
345 struct can_frame *cf = (struct can_frame *)skb->data;
347 u32 ctrl = FLEXCAN_MB_CNT_CODE(0xc) | (cf->can_dlc << 16);
349 if (can_dropped_invalid_skb(dev, skb))
352 netif_stop_queue(dev);
354 if (cf->can_id & CAN_EFF_FLAG) {
355 can_id = cf->can_id & CAN_EFF_MASK;
356 ctrl |= FLEXCAN_MB_CNT_IDE | FLEXCAN_MB_CNT_SRR;
358 can_id = (cf->can_id & CAN_SFF_MASK) << 18;
361 if (cf->can_id & CAN_RTR_FLAG)
362 ctrl |= FLEXCAN_MB_CNT_RTR;
364 if (cf->can_dlc > 0) {
365 u32 data = be32_to_cpup((__be32 *)&cf->data[0]);
366 flexcan_write(data, ®s->cantxfg[FLEXCAN_TX_BUF_ID].data[0]);
368 if (cf->can_dlc > 3) {
369 u32 data = be32_to_cpup((__be32 *)&cf->data[4]);
370 flexcan_write(data, ®s->cantxfg[FLEXCAN_TX_BUF_ID].data[1]);
373 can_put_echo_skb(skb, dev, 0);
375 flexcan_write(can_id, ®s->cantxfg[FLEXCAN_TX_BUF_ID].can_id);
376 flexcan_write(ctrl, ®s->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl);
381 static void do_bus_err(struct net_device *dev,
382 struct can_frame *cf, u32 reg_esr)
384 struct flexcan_priv *priv = netdev_priv(dev);
385 int rx_errors = 0, tx_errors = 0;
387 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
389 if (reg_esr & FLEXCAN_ESR_BIT1_ERR) {
390 netdev_dbg(dev, "BIT1_ERR irq\n");
391 cf->data[2] |= CAN_ERR_PROT_BIT1;
394 if (reg_esr & FLEXCAN_ESR_BIT0_ERR) {
395 netdev_dbg(dev, "BIT0_ERR irq\n");
396 cf->data[2] |= CAN_ERR_PROT_BIT0;
399 if (reg_esr & FLEXCAN_ESR_ACK_ERR) {
400 netdev_dbg(dev, "ACK_ERR irq\n");
401 cf->can_id |= CAN_ERR_ACK;
402 cf->data[3] |= CAN_ERR_PROT_LOC_ACK;
405 if (reg_esr & FLEXCAN_ESR_CRC_ERR) {
406 netdev_dbg(dev, "CRC_ERR irq\n");
407 cf->data[2] |= CAN_ERR_PROT_BIT;
408 cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
411 if (reg_esr & FLEXCAN_ESR_FRM_ERR) {
412 netdev_dbg(dev, "FRM_ERR irq\n");
413 cf->data[2] |= CAN_ERR_PROT_FORM;
416 if (reg_esr & FLEXCAN_ESR_STF_ERR) {
417 netdev_dbg(dev, "STF_ERR irq\n");
418 cf->data[2] |= CAN_ERR_PROT_STUFF;
422 priv->can.can_stats.bus_error++;
424 dev->stats.rx_errors++;
426 dev->stats.tx_errors++;
429 static int flexcan_poll_bus_err(struct net_device *dev, u32 reg_esr)
432 struct can_frame *cf;
434 skb = alloc_can_err_skb(dev, &cf);
438 do_bus_err(dev, cf, reg_esr);
439 netif_receive_skb(skb);
441 dev->stats.rx_packets++;
442 dev->stats.rx_bytes += cf->can_dlc;
447 static void do_state(struct net_device *dev,
448 struct can_frame *cf, enum can_state new_state)
450 struct flexcan_priv *priv = netdev_priv(dev);
451 struct can_berr_counter bec;
453 flexcan_get_berr_counter(dev, &bec);
455 switch (priv->can.state) {
456 case CAN_STATE_ERROR_ACTIVE:
459 * to : ERROR_WARNING, ERROR_PASSIVE, BUS_OFF
460 * => : there was a warning int
462 if (new_state >= CAN_STATE_ERROR_WARNING &&
463 new_state <= CAN_STATE_BUS_OFF) {
464 netdev_dbg(dev, "Error Warning IRQ\n");
465 priv->can.can_stats.error_warning++;
467 cf->can_id |= CAN_ERR_CRTL;
468 cf->data[1] = (bec.txerr > bec.rxerr) ?
469 CAN_ERR_CRTL_TX_WARNING :
470 CAN_ERR_CRTL_RX_WARNING;
472 case CAN_STATE_ERROR_WARNING: /* fallthrough */
474 * from: ERROR_ACTIVE, ERROR_WARNING
475 * to : ERROR_PASSIVE, BUS_OFF
476 * => : error passive int
478 if (new_state >= CAN_STATE_ERROR_PASSIVE &&
479 new_state <= CAN_STATE_BUS_OFF) {
480 netdev_dbg(dev, "Error Passive IRQ\n");
481 priv->can.can_stats.error_passive++;
483 cf->can_id |= CAN_ERR_CRTL;
484 cf->data[1] = (bec.txerr > bec.rxerr) ?
485 CAN_ERR_CRTL_TX_PASSIVE :
486 CAN_ERR_CRTL_RX_PASSIVE;
489 case CAN_STATE_BUS_OFF:
490 netdev_err(dev, "BUG! "
491 "hardware recovered automatically from BUS_OFF\n");
497 /* process state changes depending on the new state */
499 case CAN_STATE_ERROR_ACTIVE:
500 netdev_dbg(dev, "Error Active\n");
501 cf->can_id |= CAN_ERR_PROT;
502 cf->data[2] = CAN_ERR_PROT_ACTIVE;
504 case CAN_STATE_BUS_OFF:
505 cf->can_id |= CAN_ERR_BUSOFF;
513 static int flexcan_poll_state(struct net_device *dev, u32 reg_esr)
515 struct flexcan_priv *priv = netdev_priv(dev);
517 struct can_frame *cf;
518 enum can_state new_state;
521 flt = reg_esr & FLEXCAN_ESR_FLT_CONF_MASK;
522 if (likely(flt == FLEXCAN_ESR_FLT_CONF_ACTIVE)) {
523 if (likely(!(reg_esr & (FLEXCAN_ESR_TX_WRN |
524 FLEXCAN_ESR_RX_WRN))))
525 new_state = CAN_STATE_ERROR_ACTIVE;
527 new_state = CAN_STATE_ERROR_WARNING;
528 } else if (unlikely(flt == FLEXCAN_ESR_FLT_CONF_PASSIVE))
529 new_state = CAN_STATE_ERROR_PASSIVE;
531 new_state = CAN_STATE_BUS_OFF;
533 /* state hasn't changed */
534 if (likely(new_state == priv->can.state))
537 skb = alloc_can_err_skb(dev, &cf);
541 do_state(dev, cf, new_state);
542 priv->can.state = new_state;
543 netif_receive_skb(skb);
545 dev->stats.rx_packets++;
546 dev->stats.rx_bytes += cf->can_dlc;
551 static void flexcan_read_fifo(const struct net_device *dev,
552 struct can_frame *cf)
554 const struct flexcan_priv *priv = netdev_priv(dev);
555 struct flexcan_regs __iomem *regs = priv->base;
556 struct flexcan_mb __iomem *mb = ®s->cantxfg[0];
557 u32 reg_ctrl, reg_id;
559 reg_ctrl = flexcan_read(&mb->can_ctrl);
560 reg_id = flexcan_read(&mb->can_id);
561 if (reg_ctrl & FLEXCAN_MB_CNT_IDE)
562 cf->can_id = ((reg_id >> 0) & CAN_EFF_MASK) | CAN_EFF_FLAG;
564 cf->can_id = (reg_id >> 18) & CAN_SFF_MASK;
566 if (reg_ctrl & FLEXCAN_MB_CNT_RTR)
567 cf->can_id |= CAN_RTR_FLAG;
568 cf->can_dlc = get_can_dlc((reg_ctrl >> 16) & 0xf);
570 *(__be32 *)(cf->data + 0) = cpu_to_be32(flexcan_read(&mb->data[0]));
571 *(__be32 *)(cf->data + 4) = cpu_to_be32(flexcan_read(&mb->data[1]));
574 flexcan_write(FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, ®s->iflag1);
575 flexcan_read(®s->timer);
578 static int flexcan_read_frame(struct net_device *dev)
580 struct net_device_stats *stats = &dev->stats;
581 struct can_frame *cf;
584 skb = alloc_can_skb(dev, &cf);
585 if (unlikely(!skb)) {
590 flexcan_read_fifo(dev, cf);
591 netif_receive_skb(skb);
594 stats->rx_bytes += cf->can_dlc;
596 can_led_event(dev, CAN_LED_EVENT_RX);
601 static int flexcan_poll(struct napi_struct *napi, int quota)
603 struct net_device *dev = napi->dev;
604 const struct flexcan_priv *priv = netdev_priv(dev);
605 struct flexcan_regs __iomem *regs = priv->base;
606 u32 reg_iflag1, reg_esr;
610 * The error bits are cleared on read,
611 * use saved value from irq handler.
613 reg_esr = flexcan_read(®s->esr) | priv->reg_esr;
615 /* handle state changes */
616 work_done += flexcan_poll_state(dev, reg_esr);
619 reg_iflag1 = flexcan_read(®s->iflag1);
620 while (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE &&
622 work_done += flexcan_read_frame(dev);
623 reg_iflag1 = flexcan_read(®s->iflag1);
626 /* report bus errors */
627 if (flexcan_has_and_handle_berr(priv, reg_esr) && work_done < quota)
628 work_done += flexcan_poll_bus_err(dev, reg_esr);
630 if (work_done < quota) {
633 flexcan_write(FLEXCAN_IFLAG_DEFAULT, ®s->imask1);
634 flexcan_write(priv->reg_ctrl_default, ®s->ctrl);
640 static irqreturn_t flexcan_irq(int irq, void *dev_id)
642 struct net_device *dev = dev_id;
643 struct net_device_stats *stats = &dev->stats;
644 struct flexcan_priv *priv = netdev_priv(dev);
645 struct flexcan_regs __iomem *regs = priv->base;
646 u32 reg_iflag1, reg_esr;
648 reg_iflag1 = flexcan_read(®s->iflag1);
649 reg_esr = flexcan_read(®s->esr);
650 /* ACK all bus error and state change IRQ sources */
651 if (reg_esr & FLEXCAN_ESR_ALL_INT)
652 flexcan_write(reg_esr & FLEXCAN_ESR_ALL_INT, ®s->esr);
655 * schedule NAPI in case of:
658 * - bus error IRQ and bus error reporting is activated
660 if ((reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE) ||
661 (reg_esr & FLEXCAN_ESR_ERR_STATE) ||
662 flexcan_has_and_handle_berr(priv, reg_esr)) {
664 * The error bits are cleared on read,
665 * save them for later use.
667 priv->reg_esr = reg_esr & FLEXCAN_ESR_ERR_BUS;
668 flexcan_write(FLEXCAN_IFLAG_DEFAULT &
669 ~FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, ®s->imask1);
670 flexcan_write(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_ALL,
672 napi_schedule(&priv->napi);
676 if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_OVERFLOW) {
677 flexcan_write(FLEXCAN_IFLAG_RX_FIFO_OVERFLOW, ®s->iflag1);
678 dev->stats.rx_over_errors++;
679 dev->stats.rx_errors++;
682 /* transmission complete interrupt */
683 if (reg_iflag1 & (1 << FLEXCAN_TX_BUF_ID)) {
684 stats->tx_bytes += can_get_echo_skb(dev, 0);
686 can_led_event(dev, CAN_LED_EVENT_TX);
687 flexcan_write((1 << FLEXCAN_TX_BUF_ID), ®s->iflag1);
688 netif_wake_queue(dev);
694 static void flexcan_set_bittiming(struct net_device *dev)
696 const struct flexcan_priv *priv = netdev_priv(dev);
697 const struct can_bittiming *bt = &priv->can.bittiming;
698 struct flexcan_regs __iomem *regs = priv->base;
701 reg = flexcan_read(®s->ctrl);
702 reg &= ~(FLEXCAN_CTRL_PRESDIV(0xff) |
703 FLEXCAN_CTRL_RJW(0x3) |
704 FLEXCAN_CTRL_PSEG1(0x7) |
705 FLEXCAN_CTRL_PSEG2(0x7) |
706 FLEXCAN_CTRL_PROPSEG(0x7) |
711 reg |= FLEXCAN_CTRL_PRESDIV(bt->brp - 1) |
712 FLEXCAN_CTRL_PSEG1(bt->phase_seg1 - 1) |
713 FLEXCAN_CTRL_PSEG2(bt->phase_seg2 - 1) |
714 FLEXCAN_CTRL_RJW(bt->sjw - 1) |
715 FLEXCAN_CTRL_PROPSEG(bt->prop_seg - 1);
717 if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
718 reg |= FLEXCAN_CTRL_LPB;
719 if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
720 reg |= FLEXCAN_CTRL_LOM;
721 if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
722 reg |= FLEXCAN_CTRL_SMP;
724 netdev_info(dev, "writing ctrl=0x%08x\n", reg);
725 flexcan_write(reg, ®s->ctrl);
727 /* print chip status */
728 netdev_dbg(dev, "%s: mcr=0x%08x ctrl=0x%08x\n", __func__,
729 flexcan_read(®s->mcr), flexcan_read(®s->ctrl));
735 * this functions is entered with clocks enabled
738 static int flexcan_chip_start(struct net_device *dev)
740 struct flexcan_priv *priv = netdev_priv(dev);
741 struct flexcan_regs __iomem *regs = priv->base;
743 u32 reg_mcr, reg_ctrl;
746 err = flexcan_chip_enable(priv);
751 flexcan_write(FLEXCAN_MCR_SOFTRST, ®s->mcr);
754 reg_mcr = flexcan_read(®s->mcr);
755 if (reg_mcr & FLEXCAN_MCR_SOFTRST) {
756 netdev_err(dev, "Failed to softreset can module (mcr=0x%08x)\n",
762 flexcan_set_bittiming(dev);
770 * only supervisor access
776 reg_mcr = flexcan_read(®s->mcr);
777 reg_mcr &= ~FLEXCAN_MCR_MAXMB(0xff);
778 reg_mcr |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_FEN | FLEXCAN_MCR_HALT |
779 FLEXCAN_MCR_SUPV | FLEXCAN_MCR_WRN_EN |
780 FLEXCAN_MCR_IDAM_C | FLEXCAN_MCR_SRX_DIS |
781 FLEXCAN_MCR_MAXMB(FLEXCAN_TX_BUF_ID);
782 netdev_dbg(dev, "%s: writing mcr=0x%08x", __func__, reg_mcr);
783 flexcan_write(reg_mcr, ®s->mcr);
788 * disable timer sync feature
790 * disable auto busoff recovery
791 * transmit lowest buffer first
793 * enable tx and rx warning interrupt
794 * enable bus off interrupt
795 * (== FLEXCAN_CTRL_ERR_STATE)
797 reg_ctrl = flexcan_read(®s->ctrl);
798 reg_ctrl &= ~FLEXCAN_CTRL_TSYN;
799 reg_ctrl |= FLEXCAN_CTRL_BOFF_REC | FLEXCAN_CTRL_LBUF |
800 FLEXCAN_CTRL_ERR_STATE;
802 * enable the "error interrupt" (FLEXCAN_CTRL_ERR_MSK),
803 * on most Flexcan cores, too. Otherwise we don't get
804 * any error warning or passive interrupts.
806 if (priv->devtype_data->features & FLEXCAN_HAS_BROKEN_ERR_STATE ||
807 priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
808 reg_ctrl |= FLEXCAN_CTRL_ERR_MSK;
810 /* save for later use */
811 priv->reg_ctrl_default = reg_ctrl;
812 netdev_dbg(dev, "%s: writing ctrl=0x%08x", __func__, reg_ctrl);
813 flexcan_write(reg_ctrl, ®s->ctrl);
815 /* Abort any pending TX, mark Mailbox as INACTIVE */
816 flexcan_write(FLEXCAN_MB_CNT_CODE(0x4),
817 ®s->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl);
819 /* acceptance mask/acceptance code (accept everything) */
820 flexcan_write(0x0, ®s->rxgmask);
821 flexcan_write(0x0, ®s->rx14mask);
822 flexcan_write(0x0, ®s->rx15mask);
824 if (priv->devtype_data->features & FLEXCAN_HAS_V10_FEATURES)
825 flexcan_write(0x0, ®s->rxfgmask);
827 err = flexcan_transceiver_enable(priv);
831 /* synchronize with the can bus */
832 reg_mcr = flexcan_read(®s->mcr);
833 reg_mcr &= ~FLEXCAN_MCR_HALT;
834 flexcan_write(reg_mcr, ®s->mcr);
836 priv->can.state = CAN_STATE_ERROR_ACTIVE;
838 /* enable FIFO interrupts */
839 flexcan_write(FLEXCAN_IFLAG_DEFAULT, ®s->imask1);
841 /* print chip status */
842 netdev_dbg(dev, "%s: reading mcr=0x%08x ctrl=0x%08x\n", __func__,
843 flexcan_read(®s->mcr), flexcan_read(®s->ctrl));
848 flexcan_chip_disable(priv);
855 * this functions is entered with clocks enabled
858 static void flexcan_chip_stop(struct net_device *dev)
860 struct flexcan_priv *priv = netdev_priv(dev);
861 struct flexcan_regs __iomem *regs = priv->base;
864 /* Disable + halt module */
865 reg = flexcan_read(®s->mcr);
866 reg |= FLEXCAN_MCR_MDIS | FLEXCAN_MCR_HALT;
867 flexcan_write(reg, ®s->mcr);
869 /* Disable all interrupts */
870 flexcan_write(0, ®s->imask1);
871 flexcan_write(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_ALL,
874 flexcan_transceiver_disable(priv);
875 priv->can.state = CAN_STATE_STOPPED;
880 static int flexcan_open(struct net_device *dev)
882 struct flexcan_priv *priv = netdev_priv(dev);
885 err = clk_prepare_enable(priv->clk_ipg);
889 err = clk_prepare_enable(priv->clk_per);
891 goto out_disable_ipg;
893 err = open_candev(dev);
895 goto out_disable_per;
897 err = request_irq(dev->irq, flexcan_irq, IRQF_SHARED, dev->name, dev);
901 /* start chip and queuing */
902 err = flexcan_chip_start(dev);
906 can_led_event(dev, CAN_LED_EVENT_OPEN);
908 napi_enable(&priv->napi);
909 netif_start_queue(dev);
914 free_irq(dev->irq, dev);
918 clk_disable_unprepare(priv->clk_per);
920 clk_disable_unprepare(priv->clk_ipg);
925 static int flexcan_close(struct net_device *dev)
927 struct flexcan_priv *priv = netdev_priv(dev);
929 netif_stop_queue(dev);
930 napi_disable(&priv->napi);
931 flexcan_chip_stop(dev);
933 free_irq(dev->irq, dev);
934 clk_disable_unprepare(priv->clk_per);
935 clk_disable_unprepare(priv->clk_ipg);
939 can_led_event(dev, CAN_LED_EVENT_STOP);
944 static int flexcan_set_mode(struct net_device *dev, enum can_mode mode)
950 err = flexcan_chip_start(dev);
954 netif_wake_queue(dev);
964 static const struct net_device_ops flexcan_netdev_ops = {
965 .ndo_open = flexcan_open,
966 .ndo_stop = flexcan_close,
967 .ndo_start_xmit = flexcan_start_xmit,
970 static int register_flexcandev(struct net_device *dev)
972 struct flexcan_priv *priv = netdev_priv(dev);
973 struct flexcan_regs __iomem *regs = priv->base;
976 err = clk_prepare_enable(priv->clk_ipg);
980 err = clk_prepare_enable(priv->clk_per);
982 goto out_disable_ipg;
984 /* select "bus clock", chip must be disabled */
985 err = flexcan_chip_disable(priv);
987 goto out_disable_per;
988 reg = flexcan_read(®s->ctrl);
989 reg |= FLEXCAN_CTRL_CLK_SRC;
990 flexcan_write(reg, ®s->ctrl);
992 err = flexcan_chip_enable(priv);
994 goto out_chip_disable;
996 /* set freeze, halt and activate FIFO, restrict register access */
997 reg = flexcan_read(®s->mcr);
998 reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT |
999 FLEXCAN_MCR_FEN | FLEXCAN_MCR_SUPV;
1000 flexcan_write(reg, ®s->mcr);
1003 * Currently we only support newer versions of this core
1004 * featuring a RX FIFO. Older cores found on some Coldfire
1005 * derivates are not yet supported.
1007 reg = flexcan_read(®s->mcr);
1008 if (!(reg & FLEXCAN_MCR_FEN)) {
1009 netdev_err(dev, "Could not enable RX FIFO, unsupported core\n");
1011 goto out_chip_disable;
1014 err = register_candev(dev);
1016 /* disable core and turn off clocks */
1018 flexcan_chip_disable(priv);
1020 clk_disable_unprepare(priv->clk_per);
1022 clk_disable_unprepare(priv->clk_ipg);
1027 static void unregister_flexcandev(struct net_device *dev)
1029 unregister_candev(dev);
1032 static const struct of_device_id flexcan_of_match[] = {
1033 { .compatible = "fsl,imx6q-flexcan", .data = &fsl_imx6q_devtype_data, },
1034 { .compatible = "fsl,imx28-flexcan", .data = &fsl_imx28_devtype_data, },
1035 { .compatible = "fsl,p1010-flexcan", .data = &fsl_p1010_devtype_data, },
1038 MODULE_DEVICE_TABLE(of, flexcan_of_match);
1040 static const struct platform_device_id flexcan_id_table[] = {
1041 { .name = "flexcan", .driver_data = (kernel_ulong_t)&fsl_p1010_devtype_data, },
1044 MODULE_DEVICE_TABLE(platform, flexcan_id_table);
1046 static int flexcan_probe(struct platform_device *pdev)
1048 const struct of_device_id *of_id;
1049 const struct flexcan_devtype_data *devtype_data;
1050 struct net_device *dev;
1051 struct flexcan_priv *priv;
1052 struct resource *mem;
1053 struct clk *clk_ipg = NULL, *clk_per = NULL;
1058 if (pdev->dev.of_node)
1059 of_property_read_u32(pdev->dev.of_node,
1060 "clock-frequency", &clock_freq);
1063 clk_ipg = devm_clk_get(&pdev->dev, "ipg");
1064 if (IS_ERR(clk_ipg)) {
1065 dev_err(&pdev->dev, "no ipg clock defined\n");
1066 return PTR_ERR(clk_ipg);
1069 clk_per = devm_clk_get(&pdev->dev, "per");
1070 if (IS_ERR(clk_per)) {
1071 dev_err(&pdev->dev, "no per clock defined\n");
1072 return PTR_ERR(clk_per);
1074 clock_freq = clk_get_rate(clk_per);
1077 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1078 irq = platform_get_irq(pdev, 0);
1082 base = devm_ioremap_resource(&pdev->dev, mem);
1084 return PTR_ERR(base);
1086 of_id = of_match_device(flexcan_of_match, &pdev->dev);
1088 devtype_data = of_id->data;
1089 } else if (pdev->id_entry->driver_data) {
1090 devtype_data = (struct flexcan_devtype_data *)
1091 pdev->id_entry->driver_data;
1096 dev = alloc_candev(sizeof(struct flexcan_priv), 1);
1100 dev->netdev_ops = &flexcan_netdev_ops;
1102 dev->flags |= IFF_ECHO;
1104 priv = netdev_priv(dev);
1105 priv->can.clock.freq = clock_freq;
1106 priv->can.bittiming_const = &flexcan_bittiming_const;
1107 priv->can.do_set_mode = flexcan_set_mode;
1108 priv->can.do_get_berr_counter = flexcan_get_berr_counter;
1109 priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
1110 CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_3_SAMPLES |
1111 CAN_CTRLMODE_BERR_REPORTING;
1114 priv->clk_ipg = clk_ipg;
1115 priv->clk_per = clk_per;
1116 priv->pdata = dev_get_platdata(&pdev->dev);
1117 priv->devtype_data = devtype_data;
1119 priv->reg_xceiver = devm_regulator_get(&pdev->dev, "xceiver");
1120 if (IS_ERR(priv->reg_xceiver))
1121 priv->reg_xceiver = NULL;
1123 netif_napi_add(dev, &priv->napi, flexcan_poll, FLEXCAN_NAPI_WEIGHT);
1125 platform_set_drvdata(pdev, dev);
1126 SET_NETDEV_DEV(dev, &pdev->dev);
1128 err = register_flexcandev(dev);
1130 dev_err(&pdev->dev, "registering netdev failed\n");
1131 goto failed_register;
1134 devm_can_led_init(dev);
1136 dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%d)\n",
1137 priv->base, dev->irq);
1146 static int flexcan_remove(struct platform_device *pdev)
1148 struct net_device *dev = platform_get_drvdata(pdev);
1150 unregister_flexcandev(dev);
1157 #ifdef CONFIG_PM_SLEEP
1158 static int flexcan_suspend(struct device *device)
1160 struct net_device *dev = dev_get_drvdata(device);
1161 struct flexcan_priv *priv = netdev_priv(dev);
1164 err = flexcan_chip_disable(priv);
1168 if (netif_running(dev)) {
1169 netif_stop_queue(dev);
1170 netif_device_detach(dev);
1172 priv->can.state = CAN_STATE_SLEEPING;
1177 static int flexcan_resume(struct device *device)
1179 struct net_device *dev = dev_get_drvdata(device);
1180 struct flexcan_priv *priv = netdev_priv(dev);
1182 priv->can.state = CAN_STATE_ERROR_ACTIVE;
1183 if (netif_running(dev)) {
1184 netif_device_attach(dev);
1185 netif_start_queue(dev);
1187 return flexcan_chip_enable(priv);
1189 #endif /* CONFIG_PM_SLEEP */
1191 static SIMPLE_DEV_PM_OPS(flexcan_pm_ops, flexcan_suspend, flexcan_resume);
1193 static struct platform_driver flexcan_driver = {
1196 .owner = THIS_MODULE,
1197 .pm = &flexcan_pm_ops,
1198 .of_match_table = flexcan_of_match,
1200 .probe = flexcan_probe,
1201 .remove = flexcan_remove,
1202 .id_table = flexcan_id_table,
1205 module_platform_driver(flexcan_driver);
1207 MODULE_AUTHOR("Sascha Hauer <kernel@pengutronix.de>, "
1208 "Marc Kleine-Budde <kernel@pengutronix.de>");
1209 MODULE_LICENSE("GPL v2");
1210 MODULE_DESCRIPTION("CAN port driver for flexcan based chip");