1 /* Xilinx CAN device driver
3 * Copyright (C) 2012 - 2014 Xilinx, Inc.
4 * Copyright (C) 2009 PetaLogix. All rights reserved.
7 * This driver is developed for Axi CAN IP and for Zynq CANPS Controller.
8 * This program is free software: you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation, either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
19 #include <linux/clk.h>
20 #include <linux/errno.h>
21 #include <linux/init.h>
22 #include <linux/interrupt.h>
24 #include <linux/kernel.h>
25 #include <linux/module.h>
26 #include <linux/netdevice.h>
28 #include <linux/platform_device.h>
29 #include <linux/skbuff.h>
30 #include <linux/string.h>
31 #include <linux/types.h>
32 #include <linux/can/dev.h>
33 #include <linux/can/error.h>
34 #include <linux/can/led.h>
36 #define DRIVER_NAME "xilinx_can"
38 /* CAN registers set */
40 XCAN_SRR_OFFSET = 0x00, /* Software reset */
41 XCAN_MSR_OFFSET = 0x04, /* Mode select */
42 XCAN_BRPR_OFFSET = 0x08, /* Baud rate prescaler */
43 XCAN_BTR_OFFSET = 0x0C, /* Bit timing */
44 XCAN_ECR_OFFSET = 0x10, /* Error counter */
45 XCAN_ESR_OFFSET = 0x14, /* Error status */
46 XCAN_SR_OFFSET = 0x18, /* Status */
47 XCAN_ISR_OFFSET = 0x1C, /* Interrupt status */
48 XCAN_IER_OFFSET = 0x20, /* Interrupt enable */
49 XCAN_ICR_OFFSET = 0x24, /* Interrupt clear */
50 XCAN_TXFIFO_ID_OFFSET = 0x30,/* TX FIFO ID */
51 XCAN_TXFIFO_DLC_OFFSET = 0x34, /* TX FIFO DLC */
52 XCAN_TXFIFO_DW1_OFFSET = 0x38, /* TX FIFO Data Word 1 */
53 XCAN_TXFIFO_DW2_OFFSET = 0x3C, /* TX FIFO Data Word 2 */
54 XCAN_RXFIFO_ID_OFFSET = 0x50, /* RX FIFO ID */
55 XCAN_RXFIFO_DLC_OFFSET = 0x54, /* RX FIFO DLC */
56 XCAN_RXFIFO_DW1_OFFSET = 0x58, /* RX FIFO Data Word 1 */
57 XCAN_RXFIFO_DW2_OFFSET = 0x5C, /* RX FIFO Data Word 2 */
60 /* CAN register bit masks - XCAN_<REG>_<BIT>_MASK */
61 #define XCAN_SRR_CEN_MASK 0x00000002 /* CAN enable */
62 #define XCAN_SRR_RESET_MASK 0x00000001 /* Soft Reset the CAN core */
63 #define XCAN_MSR_LBACK_MASK 0x00000002 /* Loop back mode select */
64 #define XCAN_MSR_SLEEP_MASK 0x00000001 /* Sleep mode select */
65 #define XCAN_BRPR_BRP_MASK 0x000000FF /* Baud rate prescaler */
66 #define XCAN_BTR_SJW_MASK 0x00000180 /* Synchronous jump width */
67 #define XCAN_BTR_TS2_MASK 0x00000070 /* Time segment 2 */
68 #define XCAN_BTR_TS1_MASK 0x0000000F /* Time segment 1 */
69 #define XCAN_ECR_REC_MASK 0x0000FF00 /* Receive error counter */
70 #define XCAN_ECR_TEC_MASK 0x000000FF /* Transmit error counter */
71 #define XCAN_ESR_ACKER_MASK 0x00000010 /* ACK error */
72 #define XCAN_ESR_BERR_MASK 0x00000008 /* Bit error */
73 #define XCAN_ESR_STER_MASK 0x00000004 /* Stuff error */
74 #define XCAN_ESR_FMER_MASK 0x00000002 /* Form error */
75 #define XCAN_ESR_CRCER_MASK 0x00000001 /* CRC error */
76 #define XCAN_SR_TXFLL_MASK 0x00000400 /* TX FIFO is full */
77 #define XCAN_SR_ESTAT_MASK 0x00000180 /* Error status */
78 #define XCAN_SR_ERRWRN_MASK 0x00000040 /* Error warning */
79 #define XCAN_SR_NORMAL_MASK 0x00000008 /* Normal mode */
80 #define XCAN_SR_LBACK_MASK 0x00000002 /* Loop back mode */
81 #define XCAN_SR_CONFIG_MASK 0x00000001 /* Configuration mode */
82 #define XCAN_IXR_TXFEMP_MASK 0x00004000 /* TX FIFO Empty */
83 #define XCAN_IXR_WKUP_MASK 0x00000800 /* Wake up interrupt */
84 #define XCAN_IXR_SLP_MASK 0x00000400 /* Sleep interrupt */
85 #define XCAN_IXR_BSOFF_MASK 0x00000200 /* Bus off interrupt */
86 #define XCAN_IXR_ERROR_MASK 0x00000100 /* Error interrupt */
87 #define XCAN_IXR_RXNEMP_MASK 0x00000080 /* RX FIFO NotEmpty intr */
88 #define XCAN_IXR_RXOFLW_MASK 0x00000040 /* RX FIFO Overflow intr */
89 #define XCAN_IXR_RXOK_MASK 0x00000010 /* Message received intr */
90 #define XCAN_IXR_TXFLL_MASK 0x00000004 /* Tx FIFO Full intr */
91 #define XCAN_IXR_TXOK_MASK 0x00000002 /* TX successful intr */
92 #define XCAN_IXR_ARBLST_MASK 0x00000001 /* Arbitration lost intr */
93 #define XCAN_IDR_ID1_MASK 0xFFE00000 /* Standard msg identifier */
94 #define XCAN_IDR_SRR_MASK 0x00100000 /* Substitute remote TXreq */
95 #define XCAN_IDR_IDE_MASK 0x00080000 /* Identifier extension */
96 #define XCAN_IDR_ID2_MASK 0x0007FFFE /* Extended message ident */
97 #define XCAN_IDR_RTR_MASK 0x00000001 /* Remote TX request */
98 #define XCAN_DLCR_DLC_MASK 0xF0000000 /* Data length code */
100 #define XCAN_INTR_ALL (XCAN_IXR_TXOK_MASK | XCAN_IXR_BSOFF_MASK |\
101 XCAN_IXR_WKUP_MASK | XCAN_IXR_SLP_MASK | \
102 XCAN_IXR_RXNEMP_MASK | XCAN_IXR_ERROR_MASK | \
103 XCAN_IXR_ARBLST_MASK | XCAN_IXR_RXOK_MASK)
105 /* CAN register bit shift - XCAN_<REG>_<BIT>_SHIFT */
106 #define XCAN_BTR_SJW_SHIFT 7 /* Synchronous jump width */
107 #define XCAN_BTR_TS2_SHIFT 4 /* Time segment 2 */
108 #define XCAN_IDR_ID1_SHIFT 21 /* Standard Messg Identifier */
109 #define XCAN_IDR_ID2_SHIFT 1 /* Extended Message Identifier */
110 #define XCAN_DLCR_DLC_SHIFT 28 /* Data length code */
111 #define XCAN_ESR_REC_SHIFT 8 /* Rx Error Count */
113 /* CAN frame length constants */
114 #define XCAN_FRAME_MAX_DATA_LEN 8
115 #define XCAN_TIMEOUT (1 * HZ)
118 * struct xcan_priv - This definition define CAN driver instance
119 * @can: CAN private data structure.
120 * @tx_head: Tx CAN packets ready to send on the queue
121 * @tx_tail: Tx CAN packets successfully sended on the queue
122 * @tx_max: Maximum number packets the driver can send
123 * @napi: NAPI structure
124 * @read_reg: For reading data from CAN registers
125 * @write_reg: For writing data to CAN registers
126 * @dev: Network device data structure
127 * @reg_base: Ioremapped address to registers
128 * @irq_flags: For request_irq()
129 * @bus_clk: Pointer to struct clk
130 * @can_clk: Pointer to struct clk
134 unsigned int tx_head;
135 unsigned int tx_tail;
137 struct napi_struct napi;
138 u32 (*read_reg)(const struct xcan_priv *priv, enum xcan_reg reg);
139 void (*write_reg)(const struct xcan_priv *priv, enum xcan_reg reg,
141 struct net_device *dev;
142 void __iomem *reg_base;
143 unsigned long irq_flags;
148 /* CAN Bittiming constants as per Xilinx CAN specs */
149 static const struct can_bittiming_const xcan_bittiming_const = {
162 * xcan_write_reg_le - Write a value to the device register little endian
163 * @priv: Driver private data structure
164 * @reg: Register offset
165 * @val: Value to write at the Register offset
167 * Write data to the paricular CAN register
169 static void xcan_write_reg_le(const struct xcan_priv *priv, enum xcan_reg reg,
172 iowrite32(val, priv->reg_base + reg);
176 * xcan_read_reg_le - Read a value from the device register little endian
177 * @priv: Driver private data structure
178 * @reg: Register offset
180 * Read data from the particular CAN register
181 * Return: value read from the CAN register
183 static u32 xcan_read_reg_le(const struct xcan_priv *priv, enum xcan_reg reg)
185 return ioread32(priv->reg_base + reg);
189 * xcan_write_reg_be - Write a value to the device register big endian
190 * @priv: Driver private data structure
191 * @reg: Register offset
192 * @val: Value to write at the Register offset
194 * Write data to the paricular CAN register
196 static void xcan_write_reg_be(const struct xcan_priv *priv, enum xcan_reg reg,
199 iowrite32be(val, priv->reg_base + reg);
203 * xcan_read_reg_be - Read a value from the device register big endian
204 * @priv: Driver private data structure
205 * @reg: Register offset
207 * Read data from the particular CAN register
208 * Return: value read from the CAN register
210 static u32 xcan_read_reg_be(const struct xcan_priv *priv, enum xcan_reg reg)
212 return ioread32be(priv->reg_base + reg);
216 * set_reset_mode - Resets the CAN device mode
217 * @ndev: Pointer to net_device structure
219 * This is the driver reset mode routine.The driver
220 * enters into configuration mode.
222 * Return: 0 on success and failure value on error
224 static int set_reset_mode(struct net_device *ndev)
226 struct xcan_priv *priv = netdev_priv(ndev);
227 unsigned long timeout;
229 priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK);
231 timeout = jiffies + XCAN_TIMEOUT;
232 while (!(priv->read_reg(priv, XCAN_SR_OFFSET) & XCAN_SR_CONFIG_MASK)) {
233 if (time_after(jiffies, timeout)) {
234 netdev_warn(ndev, "timed out for config mode\n");
237 usleep_range(500, 10000);
244 * xcan_set_bittiming - CAN set bit timing routine
245 * @ndev: Pointer to net_device structure
247 * This is the driver set bittiming routine.
248 * Return: 0 on success and failure value on error
250 static int xcan_set_bittiming(struct net_device *ndev)
252 struct xcan_priv *priv = netdev_priv(ndev);
253 struct can_bittiming *bt = &priv->can.bittiming;
257 /* Check whether Xilinx CAN is in configuration mode.
258 * It cannot set bit timing if Xilinx CAN is not in configuration mode.
260 is_config_mode = priv->read_reg(priv, XCAN_SR_OFFSET) &
262 if (!is_config_mode) {
264 "BUG! Cannot set bittiming - CAN is not in config mode\n");
268 /* Setting Baud Rate prescalar value in BRPR Register */
269 btr0 = (bt->brp - 1);
271 /* Setting Time Segment 1 in BTR Register */
272 btr1 = (bt->prop_seg + bt->phase_seg1 - 1);
274 /* Setting Time Segment 2 in BTR Register */
275 btr1 |= (bt->phase_seg2 - 1) << XCAN_BTR_TS2_SHIFT;
277 /* Setting Synchronous jump width in BTR Register */
278 btr1 |= (bt->sjw - 1) << XCAN_BTR_SJW_SHIFT;
280 priv->write_reg(priv, XCAN_BRPR_OFFSET, btr0);
281 priv->write_reg(priv, XCAN_BTR_OFFSET, btr1);
283 netdev_dbg(ndev, "BRPR=0x%08x, BTR=0x%08x\n",
284 priv->read_reg(priv, XCAN_BRPR_OFFSET),
285 priv->read_reg(priv, XCAN_BTR_OFFSET));
291 * xcan_chip_start - This the drivers start routine
292 * @ndev: Pointer to net_device structure
294 * This is the drivers start routine.
295 * Based on the State of the CAN device it puts
296 * the CAN device into a proper mode.
298 * Return: 0 on success and failure value on error
300 static int xcan_chip_start(struct net_device *ndev)
302 struct xcan_priv *priv = netdev_priv(ndev);
303 u32 reg_msr, reg_sr_mask;
305 unsigned long timeout;
307 /* Check if it is in reset mode */
308 err = set_reset_mode(ndev);
312 err = xcan_set_bittiming(ndev);
316 /* Enable interrupts */
317 priv->write_reg(priv, XCAN_IER_OFFSET, XCAN_INTR_ALL);
319 /* Check whether it is loopback mode or normal mode */
320 if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
321 reg_msr = XCAN_MSR_LBACK_MASK;
322 reg_sr_mask = XCAN_SR_LBACK_MASK;
325 reg_sr_mask = XCAN_SR_NORMAL_MASK;
328 priv->write_reg(priv, XCAN_MSR_OFFSET, reg_msr);
329 priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_CEN_MASK);
331 timeout = jiffies + XCAN_TIMEOUT;
332 while (!(priv->read_reg(priv, XCAN_SR_OFFSET) & reg_sr_mask)) {
333 if (time_after(jiffies, timeout)) {
335 "timed out for correct mode\n");
339 netdev_dbg(ndev, "status:#x%08x\n",
340 priv->read_reg(priv, XCAN_SR_OFFSET));
342 priv->can.state = CAN_STATE_ERROR_ACTIVE;
347 * xcan_do_set_mode - This sets the mode of the driver
348 * @ndev: Pointer to net_device structure
349 * @mode: Tells the mode of the driver
351 * This check the drivers state and calls the
352 * the corresponding modes to set.
354 * Return: 0 on success and failure value on error
356 static int xcan_do_set_mode(struct net_device *ndev, enum can_mode mode)
362 ret = xcan_chip_start(ndev);
364 netdev_err(ndev, "xcan_chip_start failed!\n");
367 netif_wake_queue(ndev);
378 * xcan_start_xmit - Starts the transmission
379 * @skb: sk_buff pointer that contains data to be Txed
380 * @ndev: Pointer to net_device structure
382 * This function is invoked from upper layers to initiate transmission. This
383 * function uses the next available free txbuff and populates their fields to
384 * start the transmission.
386 * Return: 0 on success and failure value on error
388 static int xcan_start_xmit(struct sk_buff *skb, struct net_device *ndev)
390 struct xcan_priv *priv = netdev_priv(ndev);
391 struct net_device_stats *stats = &ndev->stats;
392 struct can_frame *cf = (struct can_frame *)skb->data;
393 u32 id, dlc, data[2] = {0, 0};
395 if (can_dropped_invalid_skb(ndev, skb))
398 /* Check if the TX buffer is full */
399 if (unlikely(priv->read_reg(priv, XCAN_SR_OFFSET) &
400 XCAN_SR_TXFLL_MASK)) {
401 netif_stop_queue(ndev);
402 netdev_err(ndev, "BUG!, TX FIFO full when queue awake!\n");
403 return NETDEV_TX_BUSY;
406 /* Watch carefully on the bit sequence */
407 if (cf->can_id & CAN_EFF_FLAG) {
408 /* Extended CAN ID format */
409 id = ((cf->can_id & CAN_EFF_MASK) << XCAN_IDR_ID2_SHIFT) &
411 id |= (((cf->can_id & CAN_EFF_MASK) >>
412 (CAN_EFF_ID_BITS-CAN_SFF_ID_BITS)) <<
413 XCAN_IDR_ID1_SHIFT) & XCAN_IDR_ID1_MASK;
415 /* The substibute remote TX request bit should be "1"
416 * for extended frames as in the Xilinx CAN datasheet
418 id |= XCAN_IDR_IDE_MASK | XCAN_IDR_SRR_MASK;
420 if (cf->can_id & CAN_RTR_FLAG)
421 /* Extended frames remote TX request */
422 id |= XCAN_IDR_RTR_MASK;
424 /* Standard CAN ID format */
425 id = ((cf->can_id & CAN_SFF_MASK) << XCAN_IDR_ID1_SHIFT) &
428 if (cf->can_id & CAN_RTR_FLAG)
429 /* Standard frames remote TX request */
430 id |= XCAN_IDR_SRR_MASK;
433 dlc = cf->can_dlc << XCAN_DLCR_DLC_SHIFT;
436 data[0] = be32_to_cpup((__be32 *)(cf->data + 0));
438 data[1] = be32_to_cpup((__be32 *)(cf->data + 4));
440 can_put_echo_skb(skb, ndev, priv->tx_head % priv->tx_max);
443 /* Write the Frame to Xilinx CAN TX FIFO */
444 priv->write_reg(priv, XCAN_TXFIFO_ID_OFFSET, id);
445 /* If the CAN frame is RTR frame this write triggers tranmission */
446 priv->write_reg(priv, XCAN_TXFIFO_DLC_OFFSET, dlc);
447 if (!(cf->can_id & CAN_RTR_FLAG)) {
448 priv->write_reg(priv, XCAN_TXFIFO_DW1_OFFSET, data[0]);
449 /* If the CAN frame is Standard/Extended frame this
450 * write triggers tranmission
452 priv->write_reg(priv, XCAN_TXFIFO_DW2_OFFSET, data[1]);
453 stats->tx_bytes += cf->can_dlc;
456 /* Check if the TX buffer is full */
457 if ((priv->tx_head - priv->tx_tail) == priv->tx_max)
458 netif_stop_queue(ndev);
464 * xcan_rx - Is called from CAN isr to complete the received
466 * @ndev: Pointer to net_device structure
468 * This function is invoked from the CAN isr(poll) to process the Rx frames. It
469 * does minimal processing and invokes "netif_receive_skb" to complete further
471 * Return: 1 on success and 0 on failure.
473 static int xcan_rx(struct net_device *ndev)
475 struct xcan_priv *priv = netdev_priv(ndev);
476 struct net_device_stats *stats = &ndev->stats;
477 struct can_frame *cf;
479 u32 id_xcan, dlc, data[2] = {0, 0};
481 skb = alloc_can_skb(ndev, &cf);
482 if (unlikely(!skb)) {
487 /* Read a frame from Xilinx zynq CANPS */
488 id_xcan = priv->read_reg(priv, XCAN_RXFIFO_ID_OFFSET);
489 dlc = priv->read_reg(priv, XCAN_RXFIFO_DLC_OFFSET) >>
492 /* Change Xilinx CAN data length format to socketCAN data format */
493 cf->can_dlc = get_can_dlc(dlc);
495 /* Change Xilinx CAN ID format to socketCAN ID format */
496 if (id_xcan & XCAN_IDR_IDE_MASK) {
497 /* The received frame is an Extended format frame */
498 cf->can_id = (id_xcan & XCAN_IDR_ID1_MASK) >> 3;
499 cf->can_id |= (id_xcan & XCAN_IDR_ID2_MASK) >>
501 cf->can_id |= CAN_EFF_FLAG;
502 if (id_xcan & XCAN_IDR_RTR_MASK)
503 cf->can_id |= CAN_RTR_FLAG;
505 /* The received frame is a standard format frame */
506 cf->can_id = (id_xcan & XCAN_IDR_ID1_MASK) >>
508 if (id_xcan & XCAN_IDR_SRR_MASK)
509 cf->can_id |= CAN_RTR_FLAG;
512 /* DW1/DW2 must always be read to remove message from RXFIFO */
513 data[0] = priv->read_reg(priv, XCAN_RXFIFO_DW1_OFFSET);
514 data[1] = priv->read_reg(priv, XCAN_RXFIFO_DW2_OFFSET);
516 if (!(cf->can_id & CAN_RTR_FLAG)) {
517 /* Change Xilinx CAN data format to socketCAN data format */
519 *(__be32 *)(cf->data) = cpu_to_be32(data[0]);
521 *(__be32 *)(cf->data + 4) = cpu_to_be32(data[1]);
524 stats->rx_bytes += cf->can_dlc;
526 netif_receive_skb(skb);
532 * xcan_err_interrupt - error frame Isr
533 * @ndev: net_device pointer
534 * @isr: interrupt status register value
536 * This is the CAN error interrupt and it will
537 * check the the type of error and forward the error
538 * frame to upper layers.
540 static void xcan_err_interrupt(struct net_device *ndev, u32 isr)
542 struct xcan_priv *priv = netdev_priv(ndev);
543 struct net_device_stats *stats = &ndev->stats;
544 struct can_frame *cf;
546 u32 err_status, status, txerr = 0, rxerr = 0;
548 skb = alloc_can_err_skb(ndev, &cf);
550 err_status = priv->read_reg(priv, XCAN_ESR_OFFSET);
551 priv->write_reg(priv, XCAN_ESR_OFFSET, err_status);
552 txerr = priv->read_reg(priv, XCAN_ECR_OFFSET) & XCAN_ECR_TEC_MASK;
553 rxerr = ((priv->read_reg(priv, XCAN_ECR_OFFSET) &
554 XCAN_ECR_REC_MASK) >> XCAN_ESR_REC_SHIFT);
555 status = priv->read_reg(priv, XCAN_SR_OFFSET);
557 if (isr & XCAN_IXR_BSOFF_MASK) {
558 priv->can.state = CAN_STATE_BUS_OFF;
559 priv->can.can_stats.bus_off++;
560 /* Leave device in Config Mode in bus-off state */
561 priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK);
564 cf->can_id |= CAN_ERR_BUSOFF;
565 } else if ((status & XCAN_SR_ESTAT_MASK) == XCAN_SR_ESTAT_MASK) {
566 priv->can.state = CAN_STATE_ERROR_PASSIVE;
567 priv->can.can_stats.error_passive++;
569 cf->can_id |= CAN_ERR_CRTL;
570 cf->data[1] = (rxerr > 127) ?
571 CAN_ERR_CRTL_RX_PASSIVE :
572 CAN_ERR_CRTL_TX_PASSIVE;
576 } else if (status & XCAN_SR_ERRWRN_MASK) {
577 priv->can.state = CAN_STATE_ERROR_WARNING;
578 priv->can.can_stats.error_warning++;
580 cf->can_id |= CAN_ERR_CRTL;
581 cf->data[1] |= (txerr > rxerr) ?
582 CAN_ERR_CRTL_TX_WARNING :
583 CAN_ERR_CRTL_RX_WARNING;
589 /* Check for Arbitration lost interrupt */
590 if (isr & XCAN_IXR_ARBLST_MASK) {
591 priv->can.can_stats.arbitration_lost++;
593 cf->can_id |= CAN_ERR_LOSTARB;
594 cf->data[0] = CAN_ERR_LOSTARB_UNSPEC;
598 /* Check for RX FIFO Overflow interrupt */
599 if (isr & XCAN_IXR_RXOFLW_MASK) {
600 stats->rx_over_errors++;
602 priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK);
604 cf->can_id |= CAN_ERR_CRTL;
605 cf->data[1] |= CAN_ERR_CRTL_RX_OVERFLOW;
609 /* Check for error interrupt */
610 if (isr & XCAN_IXR_ERROR_MASK) {
612 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
613 cf->data[2] |= CAN_ERR_PROT_UNSPEC;
616 /* Check for Ack error interrupt */
617 if (err_status & XCAN_ESR_ACKER_MASK) {
620 cf->can_id |= CAN_ERR_ACK;
621 cf->data[3] = CAN_ERR_PROT_LOC_ACK;
625 /* Check for Bit error interrupt */
626 if (err_status & XCAN_ESR_BERR_MASK) {
629 cf->can_id |= CAN_ERR_PROT;
630 cf->data[2] = CAN_ERR_PROT_BIT;
634 /* Check for Stuff error interrupt */
635 if (err_status & XCAN_ESR_STER_MASK) {
638 cf->can_id |= CAN_ERR_PROT;
639 cf->data[2] = CAN_ERR_PROT_STUFF;
643 /* Check for Form error interrupt */
644 if (err_status & XCAN_ESR_FMER_MASK) {
647 cf->can_id |= CAN_ERR_PROT;
648 cf->data[2] = CAN_ERR_PROT_FORM;
652 /* Check for CRC error interrupt */
653 if (err_status & XCAN_ESR_CRCER_MASK) {
656 cf->can_id |= CAN_ERR_PROT;
657 cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
660 priv->can.can_stats.bus_error++;
665 stats->rx_bytes += cf->can_dlc;
669 netdev_dbg(ndev, "%s: error status register:0x%x\n",
670 __func__, priv->read_reg(priv, XCAN_ESR_OFFSET));
674 * xcan_state_interrupt - It will check the state of the CAN device
675 * @ndev: net_device pointer
676 * @isr: interrupt status register value
678 * This will checks the state of the CAN device
679 * and puts the device into appropriate state.
681 static void xcan_state_interrupt(struct net_device *ndev, u32 isr)
683 struct xcan_priv *priv = netdev_priv(ndev);
685 /* Check for Sleep interrupt if set put CAN device in sleep state */
686 if (isr & XCAN_IXR_SLP_MASK)
687 priv->can.state = CAN_STATE_SLEEPING;
689 /* Check for Wake up interrupt if set put CAN device in Active state */
690 if (isr & XCAN_IXR_WKUP_MASK)
691 priv->can.state = CAN_STATE_ERROR_ACTIVE;
695 * xcan_rx_poll - Poll routine for rx packets (NAPI)
696 * @napi: napi structure pointer
697 * @quota: Max number of rx packets to be processed.
699 * This is the poll routine for rx part.
700 * It will process the packets maximux quota value.
702 * Return: number of packets received
704 static int xcan_rx_poll(struct napi_struct *napi, int quota)
706 struct net_device *ndev = napi->dev;
707 struct xcan_priv *priv = netdev_priv(ndev);
711 isr = priv->read_reg(priv, XCAN_ISR_OFFSET);
712 while ((isr & XCAN_IXR_RXNEMP_MASK) && (work_done < quota)) {
713 if (isr & XCAN_IXR_RXOK_MASK) {
714 priv->write_reg(priv, XCAN_ICR_OFFSET,
716 work_done += xcan_rx(ndev);
718 priv->write_reg(priv, XCAN_ICR_OFFSET,
719 XCAN_IXR_RXNEMP_MASK);
722 priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_RXNEMP_MASK);
723 isr = priv->read_reg(priv, XCAN_ISR_OFFSET);
727 can_led_event(ndev, CAN_LED_EVENT_RX);
729 if (work_done < quota) {
731 ier = priv->read_reg(priv, XCAN_IER_OFFSET);
732 ier |= (XCAN_IXR_RXOK_MASK | XCAN_IXR_RXNEMP_MASK);
733 priv->write_reg(priv, XCAN_IER_OFFSET, ier);
739 * xcan_tx_interrupt - Tx Done Isr
740 * @ndev: net_device pointer
741 * @isr: Interrupt status register value
743 static void xcan_tx_interrupt(struct net_device *ndev, u32 isr)
745 struct xcan_priv *priv = netdev_priv(ndev);
746 struct net_device_stats *stats = &ndev->stats;
748 while ((priv->tx_head - priv->tx_tail > 0) &&
749 (isr & XCAN_IXR_TXOK_MASK)) {
750 priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_TXOK_MASK);
751 can_get_echo_skb(ndev, priv->tx_tail %
755 isr = priv->read_reg(priv, XCAN_ISR_OFFSET);
757 can_led_event(ndev, CAN_LED_EVENT_TX);
758 netif_wake_queue(ndev);
762 * xcan_interrupt - CAN Isr
764 * @dev_id: device id poniter
766 * This is the xilinx CAN Isr. It checks for the type of interrupt
767 * and invokes the corresponding ISR.
770 * IRQ_NONE - If CAN device is in sleep mode, IRQ_HANDLED otherwise
772 static irqreturn_t xcan_interrupt(int irq, void *dev_id)
774 struct net_device *ndev = (struct net_device *)dev_id;
775 struct xcan_priv *priv = netdev_priv(ndev);
778 /* Get the interrupt status from Xilinx CAN */
779 isr = priv->read_reg(priv, XCAN_ISR_OFFSET);
783 /* Check for the type of interrupt and Processing it */
784 if (isr & (XCAN_IXR_SLP_MASK | XCAN_IXR_WKUP_MASK)) {
785 priv->write_reg(priv, XCAN_ICR_OFFSET, (XCAN_IXR_SLP_MASK |
786 XCAN_IXR_WKUP_MASK));
787 xcan_state_interrupt(ndev, isr);
790 /* Check for Tx interrupt and Processing it */
791 if (isr & XCAN_IXR_TXOK_MASK)
792 xcan_tx_interrupt(ndev, isr);
794 /* Check for the type of error interrupt and Processing it */
795 if (isr & (XCAN_IXR_ERROR_MASK | XCAN_IXR_RXOFLW_MASK |
796 XCAN_IXR_BSOFF_MASK | XCAN_IXR_ARBLST_MASK)) {
797 priv->write_reg(priv, XCAN_ICR_OFFSET, (XCAN_IXR_ERROR_MASK |
798 XCAN_IXR_RXOFLW_MASK | XCAN_IXR_BSOFF_MASK |
799 XCAN_IXR_ARBLST_MASK));
800 xcan_err_interrupt(ndev, isr);
803 /* Check for the type of receive interrupt and Processing it */
804 if (isr & (XCAN_IXR_RXNEMP_MASK | XCAN_IXR_RXOK_MASK)) {
805 ier = priv->read_reg(priv, XCAN_IER_OFFSET);
806 ier &= ~(XCAN_IXR_RXNEMP_MASK | XCAN_IXR_RXOK_MASK);
807 priv->write_reg(priv, XCAN_IER_OFFSET, ier);
808 napi_schedule(&priv->napi);
814 * xcan_chip_stop - Driver stop routine
815 * @ndev: Pointer to net_device structure
817 * This is the drivers stop routine. It will disable the
818 * interrupts and put the device into configuration mode.
820 static void xcan_chip_stop(struct net_device *ndev)
822 struct xcan_priv *priv = netdev_priv(ndev);
825 /* Disable interrupts and leave the can in configuration mode */
826 ier = priv->read_reg(priv, XCAN_IER_OFFSET);
827 ier &= ~XCAN_INTR_ALL;
828 priv->write_reg(priv, XCAN_IER_OFFSET, ier);
829 priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK);
830 priv->can.state = CAN_STATE_STOPPED;
834 * xcan_open - Driver open routine
835 * @ndev: Pointer to net_device structure
837 * This is the driver open routine.
838 * Return: 0 on success and failure value on error
840 static int xcan_open(struct net_device *ndev)
842 struct xcan_priv *priv = netdev_priv(ndev);
845 ret = request_irq(ndev->irq, xcan_interrupt, priv->irq_flags,
848 netdev_err(ndev, "irq allocation for CAN failed\n");
852 ret = clk_prepare_enable(priv->can_clk);
854 netdev_err(ndev, "unable to enable device clock\n");
858 ret = clk_prepare_enable(priv->bus_clk);
860 netdev_err(ndev, "unable to enable bus clock\n");
864 /* Set chip into reset mode */
865 ret = set_reset_mode(ndev);
867 netdev_err(ndev, "mode resetting failed!\n");
872 ret = open_candev(ndev);
876 ret = xcan_chip_start(ndev);
878 netdev_err(ndev, "xcan_chip_start failed!\n");
882 can_led_event(ndev, CAN_LED_EVENT_OPEN);
883 napi_enable(&priv->napi);
884 netif_start_queue(ndev);
891 clk_disable_unprepare(priv->bus_clk);
893 clk_disable_unprepare(priv->can_clk);
895 free_irq(ndev->irq, ndev);
901 * xcan_close - Driver close routine
902 * @ndev: Pointer to net_device structure
906 static int xcan_close(struct net_device *ndev)
908 struct xcan_priv *priv = netdev_priv(ndev);
910 netif_stop_queue(ndev);
911 napi_disable(&priv->napi);
912 xcan_chip_stop(ndev);
913 clk_disable_unprepare(priv->bus_clk);
914 clk_disable_unprepare(priv->can_clk);
915 free_irq(ndev->irq, ndev);
918 can_led_event(ndev, CAN_LED_EVENT_STOP);
924 * xcan_get_berr_counter - error counter routine
925 * @ndev: Pointer to net_device structure
926 * @bec: Pointer to can_berr_counter structure
928 * This is the driver error counter routine.
929 * Return: 0 on success and failure value on error
931 static int xcan_get_berr_counter(const struct net_device *ndev,
932 struct can_berr_counter *bec)
934 struct xcan_priv *priv = netdev_priv(ndev);
937 ret = clk_prepare_enable(priv->can_clk);
941 ret = clk_prepare_enable(priv->bus_clk);
945 bec->txerr = priv->read_reg(priv, XCAN_ECR_OFFSET) & XCAN_ECR_TEC_MASK;
946 bec->rxerr = ((priv->read_reg(priv, XCAN_ECR_OFFSET) &
947 XCAN_ECR_REC_MASK) >> XCAN_ESR_REC_SHIFT);
949 clk_disable_unprepare(priv->bus_clk);
950 clk_disable_unprepare(priv->can_clk);
955 clk_disable_unprepare(priv->can_clk);
961 static const struct net_device_ops xcan_netdev_ops = {
962 .ndo_open = xcan_open,
963 .ndo_stop = xcan_close,
964 .ndo_start_xmit = xcan_start_xmit,
965 .ndo_change_mtu = can_change_mtu,
969 * xcan_suspend - Suspend method for the driver
970 * @dev: Address of the platform_device structure
972 * Put the driver into low power mode.
975 static int __maybe_unused xcan_suspend(struct device *dev)
977 struct platform_device *pdev = dev_get_drvdata(dev);
978 struct net_device *ndev = platform_get_drvdata(pdev);
979 struct xcan_priv *priv = netdev_priv(ndev);
981 if (netif_running(ndev)) {
982 netif_stop_queue(ndev);
983 netif_device_detach(ndev);
986 priv->write_reg(priv, XCAN_MSR_OFFSET, XCAN_MSR_SLEEP_MASK);
987 priv->can.state = CAN_STATE_SLEEPING;
989 clk_disable(priv->bus_clk);
990 clk_disable(priv->can_clk);
996 * xcan_resume - Resume from suspend
997 * @dev: Address of the platformdevice structure
999 * Resume operation after suspend.
1000 * Return: 0 on success and failure value on error
1002 static int __maybe_unused xcan_resume(struct device *dev)
1004 struct platform_device *pdev = dev_get_drvdata(dev);
1005 struct net_device *ndev = platform_get_drvdata(pdev);
1006 struct xcan_priv *priv = netdev_priv(ndev);
1009 ret = clk_enable(priv->bus_clk);
1011 dev_err(dev, "Cannot enable clock.\n");
1014 ret = clk_enable(priv->can_clk);
1016 dev_err(dev, "Cannot enable clock.\n");
1017 clk_disable_unprepare(priv->bus_clk);
1021 priv->write_reg(priv, XCAN_MSR_OFFSET, 0);
1022 priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_CEN_MASK);
1023 priv->can.state = CAN_STATE_ERROR_ACTIVE;
1025 if (netif_running(ndev)) {
1026 netif_device_attach(ndev);
1027 netif_start_queue(ndev);
1033 static SIMPLE_DEV_PM_OPS(xcan_dev_pm_ops, xcan_suspend, xcan_resume);
1036 * xcan_probe - Platform registration call
1037 * @pdev: Handle to the platform device structure
1039 * This function does all the memory allocation and registration for the CAN
1042 * Return: 0 on success and failure value on error
1044 static int xcan_probe(struct platform_device *pdev)
1046 struct resource *res; /* IO mem resources */
1047 struct net_device *ndev;
1048 struct xcan_priv *priv;
1050 int ret, rx_max, tx_max;
1052 /* Get the virtual base address for the device */
1053 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1054 addr = devm_ioremap_resource(&pdev->dev, res);
1056 ret = PTR_ERR(addr);
1060 ret = of_property_read_u32(pdev->dev.of_node, "tx-fifo-depth", &tx_max);
1064 ret = of_property_read_u32(pdev->dev.of_node, "rx-fifo-depth", &rx_max);
1068 /* Create a CAN device instance */
1069 ndev = alloc_candev(sizeof(struct xcan_priv), tx_max);
1073 priv = netdev_priv(ndev);
1075 priv->can.bittiming_const = &xcan_bittiming_const;
1076 priv->can.do_set_mode = xcan_do_set_mode;
1077 priv->can.do_get_berr_counter = xcan_get_berr_counter;
1078 priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
1079 CAN_CTRLMODE_BERR_REPORTING;
1080 priv->reg_base = addr;
1081 priv->tx_max = tx_max;
1083 /* Get IRQ for the device */
1084 ndev->irq = platform_get_irq(pdev, 0);
1085 ndev->flags |= IFF_ECHO; /* We support local echo */
1087 platform_set_drvdata(pdev, ndev);
1088 SET_NETDEV_DEV(ndev, &pdev->dev);
1089 ndev->netdev_ops = &xcan_netdev_ops;
1091 /* Getting the CAN can_clk info */
1092 priv->can_clk = devm_clk_get(&pdev->dev, "can_clk");
1093 if (IS_ERR(priv->can_clk)) {
1094 dev_err(&pdev->dev, "Device clock not found.\n");
1095 ret = PTR_ERR(priv->can_clk);
1098 /* Check for type of CAN device */
1099 if (of_device_is_compatible(pdev->dev.of_node,
1100 "xlnx,zynq-can-1.0")) {
1101 priv->bus_clk = devm_clk_get(&pdev->dev, "pclk");
1102 if (IS_ERR(priv->bus_clk)) {
1103 dev_err(&pdev->dev, "bus clock not found\n");
1104 ret = PTR_ERR(priv->bus_clk);
1108 priv->bus_clk = devm_clk_get(&pdev->dev, "s_axi_aclk");
1109 if (IS_ERR(priv->bus_clk)) {
1110 dev_err(&pdev->dev, "bus clock not found\n");
1111 ret = PTR_ERR(priv->bus_clk);
1116 ret = clk_prepare_enable(priv->can_clk);
1118 dev_err(&pdev->dev, "unable to enable device clock\n");
1122 ret = clk_prepare_enable(priv->bus_clk);
1124 dev_err(&pdev->dev, "unable to enable bus clock\n");
1125 goto err_unprepare_disable_dev;
1128 priv->write_reg = xcan_write_reg_le;
1129 priv->read_reg = xcan_read_reg_le;
1131 if (priv->read_reg(priv, XCAN_SR_OFFSET) != XCAN_SR_CONFIG_MASK) {
1132 priv->write_reg = xcan_write_reg_be;
1133 priv->read_reg = xcan_read_reg_be;
1136 priv->can.clock.freq = clk_get_rate(priv->can_clk);
1138 netif_napi_add(ndev, &priv->napi, xcan_rx_poll, rx_max);
1140 ret = register_candev(ndev);
1142 dev_err(&pdev->dev, "fail to register failed (err=%d)\n", ret);
1143 goto err_unprepare_disable_busclk;
1146 devm_can_led_init(ndev);
1147 clk_disable_unprepare(priv->bus_clk);
1148 clk_disable_unprepare(priv->can_clk);
1149 netdev_dbg(ndev, "reg_base=0x%p irq=%d clock=%d, tx fifo depth:%d\n",
1150 priv->reg_base, ndev->irq, priv->can.clock.freq,
1155 err_unprepare_disable_busclk:
1156 clk_disable_unprepare(priv->bus_clk);
1157 err_unprepare_disable_dev:
1158 clk_disable_unprepare(priv->can_clk);
1166 * xcan_remove - Unregister the device after releasing the resources
1167 * @pdev: Handle to the platform device structure
1169 * This function frees all the resources allocated to the device.
1172 static int xcan_remove(struct platform_device *pdev)
1174 struct net_device *ndev = platform_get_drvdata(pdev);
1175 struct xcan_priv *priv = netdev_priv(ndev);
1177 if (set_reset_mode(ndev) < 0)
1178 netdev_err(ndev, "mode resetting failed!\n");
1180 unregister_candev(ndev);
1181 netif_napi_del(&priv->napi);
1187 /* Match table for OF platform binding */
1188 static const struct of_device_id xcan_of_match[] = {
1189 { .compatible = "xlnx,zynq-can-1.0", },
1190 { .compatible = "xlnx,axi-can-1.00.a", },
1191 { /* end of list */ },
1193 MODULE_DEVICE_TABLE(of, xcan_of_match);
1195 static struct platform_driver xcan_driver = {
1196 .probe = xcan_probe,
1197 .remove = xcan_remove,
1199 .name = DRIVER_NAME,
1200 .pm = &xcan_dev_pm_ops,
1201 .of_match_table = xcan_of_match,
1205 module_platform_driver(xcan_driver);
1207 MODULE_LICENSE("GPL");
1208 MODULE_AUTHOR("Xilinx Inc");
1209 MODULE_DESCRIPTION("Xilinx CAN interface");