1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Xilinx CAN device driver
4 * Copyright (C) 2012 - 2014 Xilinx, Inc.
5 * Copyright (C) 2009 PetaLogix. All rights reserved.
6 * Copyright (C) 2017 - 2018 Sandvik Mining and Construction Oy
9 * This driver is developed for Axi CAN IP and for Zynq CANPS Controller.
12 #include <linux/clk.h>
13 #include <linux/errno.h>
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/netdevice.h>
21 #include <linux/of_device.h>
22 #include <linux/platform_device.h>
23 #include <linux/skbuff.h>
24 #include <linux/spinlock.h>
25 #include <linux/string.h>
26 #include <linux/types.h>
27 #include <linux/can/dev.h>
28 #include <linux/can/error.h>
29 #include <linux/can/led.h>
30 #include <linux/pm_runtime.h>
32 #define DRIVER_NAME "xilinx_can"
34 /* CAN registers set */
36 XCAN_SRR_OFFSET = 0x00, /* Software reset */
37 XCAN_MSR_OFFSET = 0x04, /* Mode select */
38 XCAN_BRPR_OFFSET = 0x08, /* Baud rate prescaler */
39 XCAN_BTR_OFFSET = 0x0C, /* Bit timing */
40 XCAN_ECR_OFFSET = 0x10, /* Error counter */
41 XCAN_ESR_OFFSET = 0x14, /* Error status */
42 XCAN_SR_OFFSET = 0x18, /* Status */
43 XCAN_ISR_OFFSET = 0x1C, /* Interrupt status */
44 XCAN_IER_OFFSET = 0x20, /* Interrupt enable */
45 XCAN_ICR_OFFSET = 0x24, /* Interrupt clear */
47 /* not on CAN FD cores */
48 XCAN_TXFIFO_OFFSET = 0x30, /* TX FIFO base */
49 XCAN_RXFIFO_OFFSET = 0x50, /* RX FIFO base */
50 XCAN_AFR_OFFSET = 0x60, /* Acceptance Filter */
52 /* only on CAN FD cores */
53 XCAN_F_BRPR_OFFSET = 0x088, /* Data Phase Baud Rate
56 XCAN_F_BTR_OFFSET = 0x08C, /* Data Phase Bit Timing */
57 XCAN_TRR_OFFSET = 0x0090, /* TX Buffer Ready Request */
58 XCAN_AFR_EXT_OFFSET = 0x00E0, /* Acceptance Filter */
59 XCAN_FSR_OFFSET = 0x00E8, /* RX FIFO Status */
60 XCAN_TXMSG_BASE_OFFSET = 0x0100, /* TX Message Space */
61 XCAN_RXMSG_BASE_OFFSET = 0x1100, /* RX Message Space */
62 XCAN_RXMSG_2_BASE_OFFSET = 0x2100, /* RX Message Space */
65 #define XCAN_FRAME_ID_OFFSET(frame_base) ((frame_base) + 0x00)
66 #define XCAN_FRAME_DLC_OFFSET(frame_base) ((frame_base) + 0x04)
67 #define XCAN_FRAME_DW1_OFFSET(frame_base) ((frame_base) + 0x08)
68 #define XCAN_FRAME_DW2_OFFSET(frame_base) ((frame_base) + 0x0C)
69 #define XCANFD_FRAME_DW_OFFSET(frame_base) ((frame_base) + 0x08)
71 #define XCAN_CANFD_FRAME_SIZE 0x48
72 #define XCAN_TXMSG_FRAME_OFFSET(n) (XCAN_TXMSG_BASE_OFFSET + \
73 XCAN_CANFD_FRAME_SIZE * (n))
74 #define XCAN_RXMSG_FRAME_OFFSET(n) (XCAN_RXMSG_BASE_OFFSET + \
75 XCAN_CANFD_FRAME_SIZE * (n))
76 #define XCAN_RXMSG_2_FRAME_OFFSET(n) (XCAN_RXMSG_2_BASE_OFFSET + \
77 XCAN_CANFD_FRAME_SIZE * (n))
79 /* the single TX mailbox used by this driver on CAN FD HW */
80 #define XCAN_TX_MAILBOX_IDX 0
82 /* CAN register bit masks - XCAN_<REG>_<BIT>_MASK */
83 #define XCAN_SRR_CEN_MASK 0x00000002 /* CAN enable */
84 #define XCAN_SRR_RESET_MASK 0x00000001 /* Soft Reset the CAN core */
85 #define XCAN_MSR_LBACK_MASK 0x00000002 /* Loop back mode select */
86 #define XCAN_MSR_SLEEP_MASK 0x00000001 /* Sleep mode select */
87 #define XCAN_BRPR_BRP_MASK 0x000000FF /* Baud rate prescaler */
88 #define XCAN_BTR_SJW_MASK 0x00000180 /* Synchronous jump width */
89 #define XCAN_BTR_TS2_MASK 0x00000070 /* Time segment 2 */
90 #define XCAN_BTR_TS1_MASK 0x0000000F /* Time segment 1 */
91 #define XCAN_BTR_SJW_MASK_CANFD 0x000F0000 /* Synchronous jump width */
92 #define XCAN_BTR_TS2_MASK_CANFD 0x00000F00 /* Time segment 2 */
93 #define XCAN_BTR_TS1_MASK_CANFD 0x0000003F /* Time segment 1 */
94 #define XCAN_ECR_REC_MASK 0x0000FF00 /* Receive error counter */
95 #define XCAN_ECR_TEC_MASK 0x000000FF /* Transmit error counter */
96 #define XCAN_ESR_ACKER_MASK 0x00000010 /* ACK error */
97 #define XCAN_ESR_BERR_MASK 0x00000008 /* Bit error */
98 #define XCAN_ESR_STER_MASK 0x00000004 /* Stuff error */
99 #define XCAN_ESR_FMER_MASK 0x00000002 /* Form error */
100 #define XCAN_ESR_CRCER_MASK 0x00000001 /* CRC error */
101 #define XCAN_SR_TXFLL_MASK 0x00000400 /* TX FIFO is full */
102 #define XCAN_SR_ESTAT_MASK 0x00000180 /* Error status */
103 #define XCAN_SR_ERRWRN_MASK 0x00000040 /* Error warning */
104 #define XCAN_SR_NORMAL_MASK 0x00000008 /* Normal mode */
105 #define XCAN_SR_LBACK_MASK 0x00000002 /* Loop back mode */
106 #define XCAN_SR_CONFIG_MASK 0x00000001 /* Configuration mode */
107 #define XCAN_IXR_RXMNF_MASK 0x00020000 /* RX match not finished */
108 #define XCAN_IXR_TXFEMP_MASK 0x00004000 /* TX FIFO Empty */
109 #define XCAN_IXR_WKUP_MASK 0x00000800 /* Wake up interrupt */
110 #define XCAN_IXR_SLP_MASK 0x00000400 /* Sleep interrupt */
111 #define XCAN_IXR_BSOFF_MASK 0x00000200 /* Bus off interrupt */
112 #define XCAN_IXR_ERROR_MASK 0x00000100 /* Error interrupt */
113 #define XCAN_IXR_RXNEMP_MASK 0x00000080 /* RX FIFO NotEmpty intr */
114 #define XCAN_IXR_RXOFLW_MASK 0x00000040 /* RX FIFO Overflow intr */
115 #define XCAN_IXR_RXOK_MASK 0x00000010 /* Message received intr */
116 #define XCAN_IXR_TXFLL_MASK 0x00000004 /* Tx FIFO Full intr */
117 #define XCAN_IXR_TXOK_MASK 0x00000002 /* TX successful intr */
118 #define XCAN_IXR_ARBLST_MASK 0x00000001 /* Arbitration lost intr */
119 #define XCAN_IDR_ID1_MASK 0xFFE00000 /* Standard msg identifier */
120 #define XCAN_IDR_SRR_MASK 0x00100000 /* Substitute remote TXreq */
121 #define XCAN_IDR_IDE_MASK 0x00080000 /* Identifier extension */
122 #define XCAN_IDR_ID2_MASK 0x0007FFFE /* Extended message ident */
123 #define XCAN_IDR_RTR_MASK 0x00000001 /* Remote TX request */
124 #define XCAN_DLCR_DLC_MASK 0xF0000000 /* Data length code */
125 #define XCAN_FSR_FL_MASK 0x00003F00 /* RX Fill Level */
126 #define XCAN_2_FSR_FL_MASK 0x00007F00 /* RX Fill Level */
127 #define XCAN_FSR_IRI_MASK 0x00000080 /* RX Increment Read Index */
128 #define XCAN_FSR_RI_MASK 0x0000001F /* RX Read Index */
129 #define XCAN_2_FSR_RI_MASK 0x0000003F /* RX Read Index */
130 #define XCAN_DLCR_EDL_MASK 0x08000000 /* EDL Mask in DLC */
131 #define XCAN_DLCR_BRS_MASK 0x04000000 /* BRS Mask in DLC */
133 /* CAN register bit shift - XCAN_<REG>_<BIT>_SHIFT */
134 #define XCAN_BTR_SJW_SHIFT 7 /* Synchronous jump width */
135 #define XCAN_BTR_TS2_SHIFT 4 /* Time segment 2 */
136 #define XCAN_BTR_SJW_SHIFT_CANFD 16 /* Synchronous jump width */
137 #define XCAN_BTR_TS2_SHIFT_CANFD 8 /* Time segment 2 */
138 #define XCAN_IDR_ID1_SHIFT 21 /* Standard Messg Identifier */
139 #define XCAN_IDR_ID2_SHIFT 1 /* Extended Message Identifier */
140 #define XCAN_DLCR_DLC_SHIFT 28 /* Data length code */
141 #define XCAN_ESR_REC_SHIFT 8 /* Rx Error Count */
143 /* CAN frame length constants */
144 #define XCAN_FRAME_MAX_DATA_LEN 8
145 #define XCANFD_DW_BYTES 4
146 #define XCAN_TIMEOUT (1 * HZ)
148 /* TX-FIFO-empty interrupt available */
149 #define XCAN_FLAG_TXFEMP 0x0001
150 /* RX Match Not Finished interrupt available */
151 #define XCAN_FLAG_RXMNF 0x0002
152 /* Extended acceptance filters with control at 0xE0 */
153 #define XCAN_FLAG_EXT_FILTERS 0x0004
154 /* TX mailboxes instead of TX FIFO */
155 #define XCAN_FLAG_TX_MAILBOXES 0x0008
156 /* RX FIFO with each buffer in separate registers at 0x1100
157 * instead of the regular FIFO at 0x50
159 #define XCAN_FLAG_RX_FIFO_MULTI 0x0010
160 #define XCAN_FLAG_CANFD_2 0x0020
169 struct xcan_devtype_data {
170 enum xcan_ip_type cantype;
172 const struct can_bittiming_const *bittiming_const;
173 const char *bus_clk_name;
174 unsigned int btr_ts2_shift;
175 unsigned int btr_sjw_shift;
179 * struct xcan_priv - This definition define CAN driver instance
180 * @can: CAN private data structure.
181 * @tx_lock: Lock for synchronizing TX interrupt handling
182 * @tx_head: Tx CAN packets ready to send on the queue
183 * @tx_tail: Tx CAN packets successfully sended on the queue
184 * @tx_max: Maximum number packets the driver can send
185 * @napi: NAPI structure
186 * @read_reg: For reading data from CAN registers
187 * @write_reg: For writing data to CAN registers
188 * @dev: Network device data structure
189 * @reg_base: Ioremapped address to registers
190 * @irq_flags: For request_irq()
191 * @bus_clk: Pointer to struct clk
192 * @can_clk: Pointer to struct clk
193 * @devtype: Device type specific constants
197 spinlock_t tx_lock; /* Lock for synchronizing TX interrupt handling */
198 unsigned int tx_head;
199 unsigned int tx_tail;
201 struct napi_struct napi;
202 u32 (*read_reg)(const struct xcan_priv *priv, enum xcan_reg reg);
203 void (*write_reg)(const struct xcan_priv *priv, enum xcan_reg reg,
206 void __iomem *reg_base;
207 unsigned long irq_flags;
210 struct xcan_devtype_data devtype;
213 /* CAN Bittiming constants as per Xilinx CAN specs */
214 static const struct can_bittiming_const xcan_bittiming_const = {
226 /* AXI CANFD Arbitration Bittiming constants as per AXI CANFD 1.0 spec */
227 static const struct can_bittiming_const xcan_bittiming_const_canfd = {
239 /* AXI CANFD Data Bittiming constants as per AXI CANFD 1.0 specs */
240 static struct can_bittiming_const xcan_data_bittiming_const_canfd = {
252 /* AXI CANFD 2.0 Arbitration Bittiming constants as per AXI CANFD 2.0 spec */
253 static const struct can_bittiming_const xcan_bittiming_const_canfd2 = {
265 /* AXI CANFD 2.0 Data Bittiming constants as per AXI CANFD 2.0 spec */
266 static struct can_bittiming_const xcan_data_bittiming_const_canfd2 = {
279 * xcan_write_reg_le - Write a value to the device register little endian
280 * @priv: Driver private data structure
281 * @reg: Register offset
282 * @val: Value to write at the Register offset
284 * Write data to the paricular CAN register
286 static void xcan_write_reg_le(const struct xcan_priv *priv, enum xcan_reg reg,
289 iowrite32(val, priv->reg_base + reg);
293 * xcan_read_reg_le - Read a value from the device register little endian
294 * @priv: Driver private data structure
295 * @reg: Register offset
297 * Read data from the particular CAN register
298 * Return: value read from the CAN register
300 static u32 xcan_read_reg_le(const struct xcan_priv *priv, enum xcan_reg reg)
302 return ioread32(priv->reg_base + reg);
306 * xcan_write_reg_be - Write a value to the device register big endian
307 * @priv: Driver private data structure
308 * @reg: Register offset
309 * @val: Value to write at the Register offset
311 * Write data to the paricular CAN register
313 static void xcan_write_reg_be(const struct xcan_priv *priv, enum xcan_reg reg,
316 iowrite32be(val, priv->reg_base + reg);
320 * xcan_read_reg_be - Read a value from the device register big endian
321 * @priv: Driver private data structure
322 * @reg: Register offset
324 * Read data from the particular CAN register
325 * Return: value read from the CAN register
327 static u32 xcan_read_reg_be(const struct xcan_priv *priv, enum xcan_reg reg)
329 return ioread32be(priv->reg_base + reg);
333 * xcan_rx_int_mask - Get the mask for the receive interrupt
334 * @priv: Driver private data structure
336 * Return: The receive interrupt mask used by the driver on this HW
338 static u32 xcan_rx_int_mask(const struct xcan_priv *priv)
340 /* RXNEMP is better suited for our use case as it cannot be cleared
341 * while the FIFO is non-empty, but CAN FD HW does not have it
343 if (priv->devtype.flags & XCAN_FLAG_RX_FIFO_MULTI)
344 return XCAN_IXR_RXOK_MASK;
346 return XCAN_IXR_RXNEMP_MASK;
350 * set_reset_mode - Resets the CAN device mode
351 * @ndev: Pointer to net_device structure
353 * This is the driver reset mode routine.The driver
354 * enters into configuration mode.
356 * Return: 0 on success and failure value on error
358 static int set_reset_mode(struct net_device *ndev)
360 struct xcan_priv *priv = netdev_priv(ndev);
361 unsigned long timeout;
363 priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK);
365 timeout = jiffies + XCAN_TIMEOUT;
366 while (!(priv->read_reg(priv, XCAN_SR_OFFSET) & XCAN_SR_CONFIG_MASK)) {
367 if (time_after(jiffies, timeout)) {
368 netdev_warn(ndev, "timed out for config mode\n");
371 usleep_range(500, 10000);
374 /* reset clears FIFOs */
382 * xcan_set_bittiming - CAN set bit timing routine
383 * @ndev: Pointer to net_device structure
385 * This is the driver set bittiming routine.
386 * Return: 0 on success and failure value on error
388 static int xcan_set_bittiming(struct net_device *ndev)
390 struct xcan_priv *priv = netdev_priv(ndev);
391 struct can_bittiming *bt = &priv->can.bittiming;
392 struct can_bittiming *dbt = &priv->can.data_bittiming;
396 /* Check whether Xilinx CAN is in configuration mode.
397 * It cannot set bit timing if Xilinx CAN is not in configuration mode.
399 is_config_mode = priv->read_reg(priv, XCAN_SR_OFFSET) &
401 if (!is_config_mode) {
403 "BUG! Cannot set bittiming - CAN is not in config mode\n");
407 /* Setting Baud Rate prescalar value in BRPR Register */
408 btr0 = (bt->brp - 1);
410 /* Setting Time Segment 1 in BTR Register */
411 btr1 = (bt->prop_seg + bt->phase_seg1 - 1);
413 /* Setting Time Segment 2 in BTR Register */
414 btr1 |= (bt->phase_seg2 - 1) << priv->devtype.btr_ts2_shift;
416 /* Setting Synchronous jump width in BTR Register */
417 btr1 |= (bt->sjw - 1) << priv->devtype.btr_sjw_shift;
419 priv->write_reg(priv, XCAN_BRPR_OFFSET, btr0);
420 priv->write_reg(priv, XCAN_BTR_OFFSET, btr1);
422 if (priv->devtype.cantype == XAXI_CANFD ||
423 priv->devtype.cantype == XAXI_CANFD_2_0) {
424 /* Setting Baud Rate prescalar value in F_BRPR Register */
427 /* Setting Time Segment 1 in BTR Register */
428 btr1 = dbt->prop_seg + dbt->phase_seg1 - 1;
430 /* Setting Time Segment 2 in BTR Register */
431 btr1 |= (dbt->phase_seg2 - 1) << priv->devtype.btr_ts2_shift;
433 /* Setting Synchronous jump width in BTR Register */
434 btr1 |= (dbt->sjw - 1) << priv->devtype.btr_sjw_shift;
436 priv->write_reg(priv, XCAN_F_BRPR_OFFSET, btr0);
437 priv->write_reg(priv, XCAN_F_BTR_OFFSET, btr1);
440 netdev_dbg(ndev, "BRPR=0x%08x, BTR=0x%08x\n",
441 priv->read_reg(priv, XCAN_BRPR_OFFSET),
442 priv->read_reg(priv, XCAN_BTR_OFFSET));
448 * xcan_chip_start - This the drivers start routine
449 * @ndev: Pointer to net_device structure
451 * This is the drivers start routine.
452 * Based on the State of the CAN device it puts
453 * the CAN device into a proper mode.
455 * Return: 0 on success and failure value on error
457 static int xcan_chip_start(struct net_device *ndev)
459 struct xcan_priv *priv = netdev_priv(ndev);
464 /* Check if it is in reset mode */
465 err = set_reset_mode(ndev);
469 err = xcan_set_bittiming(ndev);
475 * We enable the ERROR interrupt even with
476 * CAN_CTRLMODE_BERR_REPORTING disabled as there is no
477 * dedicated interrupt for a state change to
478 * ERROR_WARNING/ERROR_PASSIVE.
480 ier = XCAN_IXR_TXOK_MASK | XCAN_IXR_BSOFF_MASK |
481 XCAN_IXR_WKUP_MASK | XCAN_IXR_SLP_MASK |
482 XCAN_IXR_ERROR_MASK | XCAN_IXR_RXOFLW_MASK |
483 XCAN_IXR_ARBLST_MASK | xcan_rx_int_mask(priv);
485 if (priv->devtype.flags & XCAN_FLAG_RXMNF)
486 ier |= XCAN_IXR_RXMNF_MASK;
488 priv->write_reg(priv, XCAN_IER_OFFSET, ier);
490 /* Check whether it is loopback mode or normal mode */
491 if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
492 reg_msr = XCAN_MSR_LBACK_MASK;
496 /* enable the first extended filter, if any, as cores with extended
497 * filtering default to non-receipt if all filters are disabled
499 if (priv->devtype.flags & XCAN_FLAG_EXT_FILTERS)
500 priv->write_reg(priv, XCAN_AFR_EXT_OFFSET, 0x00000001);
502 priv->write_reg(priv, XCAN_MSR_OFFSET, reg_msr);
503 priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_CEN_MASK);
505 netdev_dbg(ndev, "status:#x%08x\n",
506 priv->read_reg(priv, XCAN_SR_OFFSET));
508 priv->can.state = CAN_STATE_ERROR_ACTIVE;
513 * xcan_do_set_mode - This sets the mode of the driver
514 * @ndev: Pointer to net_device structure
515 * @mode: Tells the mode of the driver
517 * This check the drivers state and calls the
518 * the corresponding modes to set.
520 * Return: 0 on success and failure value on error
522 static int xcan_do_set_mode(struct net_device *ndev, enum can_mode mode)
528 ret = xcan_chip_start(ndev);
530 netdev_err(ndev, "xcan_chip_start failed!\n");
533 netif_wake_queue(ndev);
544 * xcan_write_frame - Write a frame to HW
545 * @ndev: Pointer to net_device structure
546 * @skb: sk_buff pointer that contains data to be Txed
547 * @frame_offset: Register offset to write the frame to
549 static void xcan_write_frame(struct net_device *ndev, struct sk_buff *skb,
552 u32 id, dlc, data[2] = {0, 0};
553 struct canfd_frame *cf = (struct canfd_frame *)skb->data;
554 u32 ramoff, dwindex = 0, i;
555 struct xcan_priv *priv = netdev_priv(ndev);
557 /* Watch carefully on the bit sequence */
558 if (cf->can_id & CAN_EFF_FLAG) {
559 /* Extended CAN ID format */
560 id = ((cf->can_id & CAN_EFF_MASK) << XCAN_IDR_ID2_SHIFT) &
562 id |= (((cf->can_id & CAN_EFF_MASK) >>
563 (CAN_EFF_ID_BITS - CAN_SFF_ID_BITS)) <<
564 XCAN_IDR_ID1_SHIFT) & XCAN_IDR_ID1_MASK;
566 /* The substibute remote TX request bit should be "1"
567 * for extended frames as in the Xilinx CAN datasheet
569 id |= XCAN_IDR_IDE_MASK | XCAN_IDR_SRR_MASK;
571 if (cf->can_id & CAN_RTR_FLAG)
572 /* Extended frames remote TX request */
573 id |= XCAN_IDR_RTR_MASK;
575 /* Standard CAN ID format */
576 id = ((cf->can_id & CAN_SFF_MASK) << XCAN_IDR_ID1_SHIFT) &
579 if (cf->can_id & CAN_RTR_FLAG)
580 /* Standard frames remote TX request */
581 id |= XCAN_IDR_SRR_MASK;
584 dlc = can_len2dlc(cf->len) << XCAN_DLCR_DLC_SHIFT;
585 if (can_is_canfd_skb(skb)) {
586 if (cf->flags & CANFD_BRS)
587 dlc |= XCAN_DLCR_BRS_MASK;
588 dlc |= XCAN_DLCR_EDL_MASK;
591 if (!(priv->devtype.flags & XCAN_FLAG_TX_MAILBOXES) &&
592 (priv->devtype.flags & XCAN_FLAG_TXFEMP))
593 can_put_echo_skb(skb, ndev, priv->tx_head % priv->tx_max);
595 can_put_echo_skb(skb, ndev, 0);
599 priv->write_reg(priv, XCAN_FRAME_ID_OFFSET(frame_offset), id);
600 /* If the CAN frame is RTR frame this write triggers transmission
603 priv->write_reg(priv, XCAN_FRAME_DLC_OFFSET(frame_offset), dlc);
604 if (priv->devtype.cantype == XAXI_CANFD ||
605 priv->devtype.cantype == XAXI_CANFD_2_0) {
606 for (i = 0; i < cf->len; i += 4) {
607 ramoff = XCANFD_FRAME_DW_OFFSET(frame_offset) +
608 (dwindex * XCANFD_DW_BYTES);
609 priv->write_reg(priv, ramoff,
610 be32_to_cpup((__be32 *)(cf->data + i)));
615 data[0] = be32_to_cpup((__be32 *)(cf->data + 0));
617 data[1] = be32_to_cpup((__be32 *)(cf->data + 4));
619 if (!(cf->can_id & CAN_RTR_FLAG)) {
620 priv->write_reg(priv,
621 XCAN_FRAME_DW1_OFFSET(frame_offset),
623 /* If the CAN frame is Standard/Extended frame this
624 * write triggers transmission (not on CAN FD)
626 priv->write_reg(priv,
627 XCAN_FRAME_DW2_OFFSET(frame_offset),
634 * xcan_start_xmit_fifo - Starts the transmission (FIFO mode)
635 * @skb: sk_buff pointer that contains data to be Txed
636 * @ndev: Pointer to net_device structure
638 * Return: 0 on success, -ENOSPC if FIFO is full.
640 static int xcan_start_xmit_fifo(struct sk_buff *skb, struct net_device *ndev)
642 struct xcan_priv *priv = netdev_priv(ndev);
645 /* Check if the TX buffer is full */
646 if (unlikely(priv->read_reg(priv, XCAN_SR_OFFSET) &
650 spin_lock_irqsave(&priv->tx_lock, flags);
652 xcan_write_frame(ndev, skb, XCAN_TXFIFO_OFFSET);
654 /* Clear TX-FIFO-empty interrupt for xcan_tx_interrupt() */
655 if (priv->tx_max > 1)
656 priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_TXFEMP_MASK);
658 /* Check if the TX buffer is full */
659 if ((priv->tx_head - priv->tx_tail) == priv->tx_max)
660 netif_stop_queue(ndev);
662 spin_unlock_irqrestore(&priv->tx_lock, flags);
668 * xcan_start_xmit_mailbox - Starts the transmission (mailbox mode)
669 * @skb: sk_buff pointer that contains data to be Txed
670 * @ndev: Pointer to net_device structure
672 * Return: 0 on success, -ENOSPC if there is no space
674 static int xcan_start_xmit_mailbox(struct sk_buff *skb, struct net_device *ndev)
676 struct xcan_priv *priv = netdev_priv(ndev);
679 if (unlikely(priv->read_reg(priv, XCAN_TRR_OFFSET) &
680 BIT(XCAN_TX_MAILBOX_IDX)))
683 spin_lock_irqsave(&priv->tx_lock, flags);
685 xcan_write_frame(ndev, skb,
686 XCAN_TXMSG_FRAME_OFFSET(XCAN_TX_MAILBOX_IDX));
688 /* Mark buffer as ready for transmit */
689 priv->write_reg(priv, XCAN_TRR_OFFSET, BIT(XCAN_TX_MAILBOX_IDX));
691 netif_stop_queue(ndev);
693 spin_unlock_irqrestore(&priv->tx_lock, flags);
699 * xcan_start_xmit - Starts the transmission
700 * @skb: sk_buff pointer that contains data to be Txed
701 * @ndev: Pointer to net_device structure
703 * This function is invoked from upper layers to initiate transmission.
705 * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY when the tx queue is full
707 static netdev_tx_t xcan_start_xmit(struct sk_buff *skb, struct net_device *ndev)
709 struct xcan_priv *priv = netdev_priv(ndev);
712 if (can_dropped_invalid_skb(ndev, skb))
715 if (priv->devtype.flags & XCAN_FLAG_TX_MAILBOXES)
716 ret = xcan_start_xmit_mailbox(skb, ndev);
718 ret = xcan_start_xmit_fifo(skb, ndev);
721 netdev_err(ndev, "BUG!, TX full when queue awake!\n");
722 netif_stop_queue(ndev);
723 return NETDEV_TX_BUSY;
730 * xcan_rx - Is called from CAN isr to complete the received
732 * @ndev: Pointer to net_device structure
733 * @frame_base: Register offset to the frame to be read
735 * This function is invoked from the CAN isr(poll) to process the Rx frames. It
736 * does minimal processing and invokes "netif_receive_skb" to complete further
738 * Return: 1 on success and 0 on failure.
740 static int xcan_rx(struct net_device *ndev, int frame_base)
742 struct xcan_priv *priv = netdev_priv(ndev);
743 struct net_device_stats *stats = &ndev->stats;
744 struct can_frame *cf;
746 u32 id_xcan, dlc, data[2] = {0, 0};
748 skb = alloc_can_skb(ndev, &cf);
749 if (unlikely(!skb)) {
754 /* Read a frame from Xilinx zynq CANPS */
755 id_xcan = priv->read_reg(priv, XCAN_FRAME_ID_OFFSET(frame_base));
756 dlc = priv->read_reg(priv, XCAN_FRAME_DLC_OFFSET(frame_base)) >>
759 /* Change Xilinx CAN data length format to socketCAN data format */
760 cf->can_dlc = get_can_dlc(dlc);
762 /* Change Xilinx CAN ID format to socketCAN ID format */
763 if (id_xcan & XCAN_IDR_IDE_MASK) {
764 /* The received frame is an Extended format frame */
765 cf->can_id = (id_xcan & XCAN_IDR_ID1_MASK) >> 3;
766 cf->can_id |= (id_xcan & XCAN_IDR_ID2_MASK) >>
768 cf->can_id |= CAN_EFF_FLAG;
769 if (id_xcan & XCAN_IDR_RTR_MASK)
770 cf->can_id |= CAN_RTR_FLAG;
772 /* The received frame is a standard format frame */
773 cf->can_id = (id_xcan & XCAN_IDR_ID1_MASK) >>
775 if (id_xcan & XCAN_IDR_SRR_MASK)
776 cf->can_id |= CAN_RTR_FLAG;
779 /* DW1/DW2 must always be read to remove message from RXFIFO */
780 data[0] = priv->read_reg(priv, XCAN_FRAME_DW1_OFFSET(frame_base));
781 data[1] = priv->read_reg(priv, XCAN_FRAME_DW2_OFFSET(frame_base));
783 if (!(cf->can_id & CAN_RTR_FLAG)) {
784 /* Change Xilinx CAN data format to socketCAN data format */
786 *(__be32 *)(cf->data) = cpu_to_be32(data[0]);
788 *(__be32 *)(cf->data + 4) = cpu_to_be32(data[1]);
791 stats->rx_bytes += cf->can_dlc;
793 netif_receive_skb(skb);
799 * xcanfd_rx - Is called from CAN isr to complete the received
801 * @ndev: Pointer to net_device structure
802 * @frame_base: Register offset to the frame to be read
804 * This function is invoked from the CAN isr(poll) to process the Rx frames. It
805 * does minimal processing and invokes "netif_receive_skb" to complete further
807 * Return: 1 on success and 0 on failure.
809 static int xcanfd_rx(struct net_device *ndev, int frame_base)
811 struct xcan_priv *priv = netdev_priv(ndev);
812 struct net_device_stats *stats = &ndev->stats;
813 struct canfd_frame *cf;
815 u32 id_xcan, dlc, data[2] = {0, 0}, dwindex = 0, i, dw_offset;
817 id_xcan = priv->read_reg(priv, XCAN_FRAME_ID_OFFSET(frame_base));
818 dlc = priv->read_reg(priv, XCAN_FRAME_DLC_OFFSET(frame_base));
819 if (dlc & XCAN_DLCR_EDL_MASK)
820 skb = alloc_canfd_skb(ndev, &cf);
822 skb = alloc_can_skb(ndev, (struct can_frame **)&cf);
824 if (unlikely(!skb)) {
829 /* Change Xilinx CANFD data length format to socketCAN data
832 if (dlc & XCAN_DLCR_EDL_MASK)
833 cf->len = can_dlc2len((dlc & XCAN_DLCR_DLC_MASK) >>
834 XCAN_DLCR_DLC_SHIFT);
836 cf->len = get_can_dlc((dlc & XCAN_DLCR_DLC_MASK) >>
837 XCAN_DLCR_DLC_SHIFT);
839 /* Change Xilinx CAN ID format to socketCAN ID format */
840 if (id_xcan & XCAN_IDR_IDE_MASK) {
841 /* The received frame is an Extended format frame */
842 cf->can_id = (id_xcan & XCAN_IDR_ID1_MASK) >> 3;
843 cf->can_id |= (id_xcan & XCAN_IDR_ID2_MASK) >>
845 cf->can_id |= CAN_EFF_FLAG;
846 if (id_xcan & XCAN_IDR_RTR_MASK)
847 cf->can_id |= CAN_RTR_FLAG;
849 /* The received frame is a standard format frame */
850 cf->can_id = (id_xcan & XCAN_IDR_ID1_MASK) >>
852 if (!(dlc & XCAN_DLCR_EDL_MASK) && (id_xcan &
854 cf->can_id |= CAN_RTR_FLAG;
857 /* Check the frame received is FD or not*/
858 if (dlc & XCAN_DLCR_EDL_MASK) {
859 for (i = 0; i < cf->len; i += 4) {
860 dw_offset = XCANFD_FRAME_DW_OFFSET(frame_base) +
861 (dwindex * XCANFD_DW_BYTES);
862 data[0] = priv->read_reg(priv, dw_offset);
863 *(__be32 *)(cf->data + i) = cpu_to_be32(data[0]);
867 for (i = 0; i < cf->len; i += 4) {
868 dw_offset = XCANFD_FRAME_DW_OFFSET(frame_base);
869 data[0] = priv->read_reg(priv, dw_offset + i);
870 *(__be32 *)(cf->data + i) = cpu_to_be32(data[0]);
873 stats->rx_bytes += cf->len;
875 netif_receive_skb(skb);
881 * xcan_current_error_state - Get current error state from HW
882 * @ndev: Pointer to net_device structure
884 * Checks the current CAN error state from the HW. Note that this
885 * only checks for ERROR_PASSIVE and ERROR_WARNING.
888 * ERROR_PASSIVE or ERROR_WARNING if either is active, ERROR_ACTIVE
891 static enum can_state xcan_current_error_state(struct net_device *ndev)
893 struct xcan_priv *priv = netdev_priv(ndev);
894 u32 status = priv->read_reg(priv, XCAN_SR_OFFSET);
896 if ((status & XCAN_SR_ESTAT_MASK) == XCAN_SR_ESTAT_MASK)
897 return CAN_STATE_ERROR_PASSIVE;
898 else if (status & XCAN_SR_ERRWRN_MASK)
899 return CAN_STATE_ERROR_WARNING;
901 return CAN_STATE_ERROR_ACTIVE;
905 * xcan_set_error_state - Set new CAN error state
906 * @ndev: Pointer to net_device structure
907 * @new_state: The new CAN state to be set
908 * @cf: Error frame to be populated or NULL
910 * Set new CAN error state for the device, updating statistics and
911 * populating the error frame if given.
913 static void xcan_set_error_state(struct net_device *ndev,
914 enum can_state new_state,
915 struct can_frame *cf)
917 struct xcan_priv *priv = netdev_priv(ndev);
918 u32 ecr = priv->read_reg(priv, XCAN_ECR_OFFSET);
919 u32 txerr = ecr & XCAN_ECR_TEC_MASK;
920 u32 rxerr = (ecr & XCAN_ECR_REC_MASK) >> XCAN_ESR_REC_SHIFT;
921 enum can_state tx_state = txerr >= rxerr ? new_state : 0;
922 enum can_state rx_state = txerr <= rxerr ? new_state : 0;
924 /* non-ERROR states are handled elsewhere */
925 if (WARN_ON(new_state > CAN_STATE_ERROR_PASSIVE))
928 can_change_state(ndev, cf, tx_state, rx_state);
937 * xcan_update_error_state_after_rxtx - Update CAN error state after RX/TX
938 * @ndev: Pointer to net_device structure
940 * If the device is in a ERROR-WARNING or ERROR-PASSIVE state, check if
941 * the performed RX/TX has caused it to drop to a lesser state and set
942 * the interface state accordingly.
944 static void xcan_update_error_state_after_rxtx(struct net_device *ndev)
946 struct xcan_priv *priv = netdev_priv(ndev);
947 enum can_state old_state = priv->can.state;
948 enum can_state new_state;
950 /* changing error state due to successful frame RX/TX can only
951 * occur from these states
953 if (old_state != CAN_STATE_ERROR_WARNING &&
954 old_state != CAN_STATE_ERROR_PASSIVE)
957 new_state = xcan_current_error_state(ndev);
959 if (new_state != old_state) {
961 struct can_frame *cf;
963 skb = alloc_can_err_skb(ndev, &cf);
965 xcan_set_error_state(ndev, new_state, skb ? cf : NULL);
968 struct net_device_stats *stats = &ndev->stats;
971 stats->rx_bytes += cf->can_dlc;
978 * xcan_err_interrupt - error frame Isr
979 * @ndev: net_device pointer
980 * @isr: interrupt status register value
982 * This is the CAN error interrupt and it will
983 * check the the type of error and forward the error
984 * frame to upper layers.
986 static void xcan_err_interrupt(struct net_device *ndev, u32 isr)
988 struct xcan_priv *priv = netdev_priv(ndev);
989 struct net_device_stats *stats = &ndev->stats;
990 struct can_frame cf = { };
993 err_status = priv->read_reg(priv, XCAN_ESR_OFFSET);
994 priv->write_reg(priv, XCAN_ESR_OFFSET, err_status);
996 if (isr & XCAN_IXR_BSOFF_MASK) {
997 priv->can.state = CAN_STATE_BUS_OFF;
998 priv->can.can_stats.bus_off++;
999 /* Leave device in Config Mode in bus-off state */
1000 priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK);
1002 cf.can_id |= CAN_ERR_BUSOFF;
1004 enum can_state new_state = xcan_current_error_state(ndev);
1006 if (new_state != priv->can.state)
1007 xcan_set_error_state(ndev, new_state, &cf);
1010 /* Check for Arbitration lost interrupt */
1011 if (isr & XCAN_IXR_ARBLST_MASK) {
1012 priv->can.can_stats.arbitration_lost++;
1013 cf.can_id |= CAN_ERR_LOSTARB;
1014 cf.data[0] = CAN_ERR_LOSTARB_UNSPEC;
1017 /* Check for RX FIFO Overflow interrupt */
1018 if (isr & XCAN_IXR_RXOFLW_MASK) {
1019 stats->rx_over_errors++;
1021 cf.can_id |= CAN_ERR_CRTL;
1022 cf.data[1] |= CAN_ERR_CRTL_RX_OVERFLOW;
1025 /* Check for RX Match Not Finished interrupt */
1026 if (isr & XCAN_IXR_RXMNF_MASK) {
1027 stats->rx_dropped++;
1029 netdev_err(ndev, "RX match not finished, frame discarded\n");
1030 cf.can_id |= CAN_ERR_CRTL;
1031 cf.data[1] |= CAN_ERR_CRTL_UNSPEC;
1034 /* Check for error interrupt */
1035 if (isr & XCAN_IXR_ERROR_MASK) {
1036 bool berr_reporting = false;
1038 if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) {
1039 berr_reporting = true;
1040 cf.can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
1043 /* Check for Ack error interrupt */
1044 if (err_status & XCAN_ESR_ACKER_MASK) {
1046 if (berr_reporting) {
1047 cf.can_id |= CAN_ERR_ACK;
1048 cf.data[3] = CAN_ERR_PROT_LOC_ACK;
1052 /* Check for Bit error interrupt */
1053 if (err_status & XCAN_ESR_BERR_MASK) {
1055 if (berr_reporting) {
1056 cf.can_id |= CAN_ERR_PROT;
1057 cf.data[2] = CAN_ERR_PROT_BIT;
1061 /* Check for Stuff error interrupt */
1062 if (err_status & XCAN_ESR_STER_MASK) {
1064 if (berr_reporting) {
1065 cf.can_id |= CAN_ERR_PROT;
1066 cf.data[2] = CAN_ERR_PROT_STUFF;
1070 /* Check for Form error interrupt */
1071 if (err_status & XCAN_ESR_FMER_MASK) {
1073 if (berr_reporting) {
1074 cf.can_id |= CAN_ERR_PROT;
1075 cf.data[2] = CAN_ERR_PROT_FORM;
1079 /* Check for CRC error interrupt */
1080 if (err_status & XCAN_ESR_CRCER_MASK) {
1082 if (berr_reporting) {
1083 cf.can_id |= CAN_ERR_PROT;
1084 cf.data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
1087 priv->can.can_stats.bus_error++;
1091 struct can_frame *skb_cf;
1092 struct sk_buff *skb = alloc_can_err_skb(ndev, &skb_cf);
1095 skb_cf->can_id |= cf.can_id;
1096 memcpy(skb_cf->data, cf.data, CAN_ERR_DLC);
1097 stats->rx_packets++;
1098 stats->rx_bytes += CAN_ERR_DLC;
1103 netdev_dbg(ndev, "%s: error status register:0x%x\n",
1104 __func__, priv->read_reg(priv, XCAN_ESR_OFFSET));
1108 * xcan_state_interrupt - It will check the state of the CAN device
1109 * @ndev: net_device pointer
1110 * @isr: interrupt status register value
1112 * This will checks the state of the CAN device
1113 * and puts the device into appropriate state.
1115 static void xcan_state_interrupt(struct net_device *ndev, u32 isr)
1117 struct xcan_priv *priv = netdev_priv(ndev);
1119 /* Check for Sleep interrupt if set put CAN device in sleep state */
1120 if (isr & XCAN_IXR_SLP_MASK)
1121 priv->can.state = CAN_STATE_SLEEPING;
1123 /* Check for Wake up interrupt if set put CAN device in Active state */
1124 if (isr & XCAN_IXR_WKUP_MASK)
1125 priv->can.state = CAN_STATE_ERROR_ACTIVE;
1129 * xcan_rx_fifo_get_next_frame - Get register offset of next RX frame
1130 * @priv: Driver private data structure
1132 * Return: Register offset of the next frame in RX FIFO.
1134 static int xcan_rx_fifo_get_next_frame(struct xcan_priv *priv)
1138 if (priv->devtype.flags & XCAN_FLAG_RX_FIFO_MULTI) {
1141 /* clear RXOK before the is-empty check so that any newly
1142 * received frame will reassert it without a race
1144 priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_RXOK_MASK);
1146 fsr = priv->read_reg(priv, XCAN_FSR_OFFSET);
1148 /* check if RX FIFO is empty */
1149 if (priv->devtype.flags & XCAN_FLAG_CANFD_2)
1150 mask = XCAN_2_FSR_FL_MASK;
1152 mask = XCAN_FSR_FL_MASK;
1157 if (priv->devtype.flags & XCAN_FLAG_CANFD_2)
1159 XCAN_RXMSG_2_FRAME_OFFSET(fsr & XCAN_2_FSR_RI_MASK);
1162 XCAN_RXMSG_FRAME_OFFSET(fsr & XCAN_FSR_RI_MASK);
1165 /* check if RX FIFO is empty */
1166 if (!(priv->read_reg(priv, XCAN_ISR_OFFSET) &
1167 XCAN_IXR_RXNEMP_MASK))
1170 /* frames are read from a static offset */
1171 offset = XCAN_RXFIFO_OFFSET;
1178 * xcan_rx_poll - Poll routine for rx packets (NAPI)
1179 * @napi: napi structure pointer
1180 * @quota: Max number of rx packets to be processed.
1182 * This is the poll routine for rx part.
1183 * It will process the packets maximux quota value.
1185 * Return: number of packets received
1187 static int xcan_rx_poll(struct napi_struct *napi, int quota)
1189 struct net_device *ndev = napi->dev;
1190 struct xcan_priv *priv = netdev_priv(ndev);
1195 while ((frame_offset = xcan_rx_fifo_get_next_frame(priv)) >= 0 &&
1196 (work_done < quota)) {
1197 if (xcan_rx_int_mask(priv) & XCAN_IXR_RXOK_MASK)
1198 work_done += xcanfd_rx(ndev, frame_offset);
1200 work_done += xcan_rx(ndev, frame_offset);
1202 if (priv->devtype.flags & XCAN_FLAG_RX_FIFO_MULTI)
1203 /* increment read index */
1204 priv->write_reg(priv, XCAN_FSR_OFFSET,
1207 /* clear rx-not-empty (will actually clear only if
1210 priv->write_reg(priv, XCAN_ICR_OFFSET,
1211 XCAN_IXR_RXNEMP_MASK);
1215 can_led_event(ndev, CAN_LED_EVENT_RX);
1216 xcan_update_error_state_after_rxtx(ndev);
1219 if (work_done < quota) {
1220 napi_complete_done(napi, work_done);
1221 ier = priv->read_reg(priv, XCAN_IER_OFFSET);
1222 ier |= xcan_rx_int_mask(priv);
1223 priv->write_reg(priv, XCAN_IER_OFFSET, ier);
1229 * xcan_tx_interrupt - Tx Done Isr
1230 * @ndev: net_device pointer
1231 * @isr: Interrupt status register value
1233 static void xcan_tx_interrupt(struct net_device *ndev, u32 isr)
1235 struct xcan_priv *priv = netdev_priv(ndev);
1236 struct net_device_stats *stats = &ndev->stats;
1237 unsigned int frames_in_fifo;
1238 int frames_sent = 1; /* TXOK => at least 1 frame was sent */
1239 unsigned long flags;
1242 /* Synchronize with xmit as we need to know the exact number
1243 * of frames in the FIFO to stay in sync due to the TXFEMP
1245 * This also prevents a race between netif_wake_queue() and
1246 * netif_stop_queue().
1248 spin_lock_irqsave(&priv->tx_lock, flags);
1250 frames_in_fifo = priv->tx_head - priv->tx_tail;
1252 if (WARN_ON_ONCE(frames_in_fifo == 0)) {
1253 /* clear TXOK anyway to avoid getting back here */
1254 priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_TXOK_MASK);
1255 spin_unlock_irqrestore(&priv->tx_lock, flags);
1259 /* Check if 2 frames were sent (TXOK only means that at least 1
1262 if (frames_in_fifo > 1) {
1263 WARN_ON(frames_in_fifo > priv->tx_max);
1265 /* Synchronize TXOK and isr so that after the loop:
1266 * (1) isr variable is up-to-date at least up to TXOK clear
1267 * time. This avoids us clearing a TXOK of a second frame
1268 * but not noticing that the FIFO is now empty and thus
1269 * marking only a single frame as sent.
1270 * (2) No TXOK is left. Having one could mean leaving a
1271 * stray TXOK as we might process the associated frame
1272 * via TXFEMP handling as we read TXFEMP *after* TXOK
1273 * clear to satisfy (1).
1275 while ((isr & XCAN_IXR_TXOK_MASK) &&
1276 !WARN_ON(++retries == 100)) {
1277 priv->write_reg(priv, XCAN_ICR_OFFSET,
1278 XCAN_IXR_TXOK_MASK);
1279 isr = priv->read_reg(priv, XCAN_ISR_OFFSET);
1282 if (isr & XCAN_IXR_TXFEMP_MASK) {
1283 /* nothing in FIFO anymore */
1284 frames_sent = frames_in_fifo;
1287 /* single frame in fifo, just clear TXOK */
1288 priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_TXOK_MASK);
1291 while (frames_sent--) {
1292 stats->tx_bytes += can_get_echo_skb(ndev, priv->tx_tail %
1295 stats->tx_packets++;
1298 netif_wake_queue(ndev);
1300 spin_unlock_irqrestore(&priv->tx_lock, flags);
1302 can_led_event(ndev, CAN_LED_EVENT_TX);
1303 xcan_update_error_state_after_rxtx(ndev);
1307 * xcan_interrupt - CAN Isr
1309 * @dev_id: device id poniter
1311 * This is the xilinx CAN Isr. It checks for the type of interrupt
1312 * and invokes the corresponding ISR.
1315 * IRQ_NONE - If CAN device is in sleep mode, IRQ_HANDLED otherwise
1317 static irqreturn_t xcan_interrupt(int irq, void *dev_id)
1319 struct net_device *ndev = (struct net_device *)dev_id;
1320 struct xcan_priv *priv = netdev_priv(ndev);
1323 u32 rx_int_mask = xcan_rx_int_mask(priv);
1325 /* Get the interrupt status from Xilinx CAN */
1326 isr = priv->read_reg(priv, XCAN_ISR_OFFSET);
1330 /* Check for the type of interrupt and Processing it */
1331 if (isr & (XCAN_IXR_SLP_MASK | XCAN_IXR_WKUP_MASK)) {
1332 priv->write_reg(priv, XCAN_ICR_OFFSET, (XCAN_IXR_SLP_MASK |
1333 XCAN_IXR_WKUP_MASK));
1334 xcan_state_interrupt(ndev, isr);
1337 /* Check for Tx interrupt and Processing it */
1338 if (isr & XCAN_IXR_TXOK_MASK)
1339 xcan_tx_interrupt(ndev, isr);
1341 /* Check for the type of error interrupt and Processing it */
1342 isr_errors = isr & (XCAN_IXR_ERROR_MASK | XCAN_IXR_RXOFLW_MASK |
1343 XCAN_IXR_BSOFF_MASK | XCAN_IXR_ARBLST_MASK |
1344 XCAN_IXR_RXMNF_MASK);
1346 priv->write_reg(priv, XCAN_ICR_OFFSET, isr_errors);
1347 xcan_err_interrupt(ndev, isr);
1350 /* Check for the type of receive interrupt and Processing it */
1351 if (isr & rx_int_mask) {
1352 ier = priv->read_reg(priv, XCAN_IER_OFFSET);
1353 ier &= ~rx_int_mask;
1354 priv->write_reg(priv, XCAN_IER_OFFSET, ier);
1355 napi_schedule(&priv->napi);
1361 * xcan_chip_stop - Driver stop routine
1362 * @ndev: Pointer to net_device structure
1364 * This is the drivers stop routine. It will disable the
1365 * interrupts and put the device into configuration mode.
1367 static void xcan_chip_stop(struct net_device *ndev)
1369 struct xcan_priv *priv = netdev_priv(ndev);
1371 /* Disable interrupts and leave the can in configuration mode */
1372 set_reset_mode(ndev);
1373 priv->can.state = CAN_STATE_STOPPED;
1377 * xcan_open - Driver open routine
1378 * @ndev: Pointer to net_device structure
1380 * This is the driver open routine.
1381 * Return: 0 on success and failure value on error
1383 static int xcan_open(struct net_device *ndev)
1385 struct xcan_priv *priv = netdev_priv(ndev);
1388 ret = pm_runtime_get_sync(priv->dev);
1390 netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
1395 ret = request_irq(ndev->irq, xcan_interrupt, priv->irq_flags,
1398 netdev_err(ndev, "irq allocation for CAN failed\n");
1402 /* Set chip into reset mode */
1403 ret = set_reset_mode(ndev);
1405 netdev_err(ndev, "mode resetting failed!\n");
1410 ret = open_candev(ndev);
1414 ret = xcan_chip_start(ndev);
1416 netdev_err(ndev, "xcan_chip_start failed!\n");
1420 can_led_event(ndev, CAN_LED_EVENT_OPEN);
1421 napi_enable(&priv->napi);
1422 netif_start_queue(ndev);
1429 free_irq(ndev->irq, ndev);
1431 pm_runtime_put(priv->dev);
1437 * xcan_close - Driver close routine
1438 * @ndev: Pointer to net_device structure
1442 static int xcan_close(struct net_device *ndev)
1444 struct xcan_priv *priv = netdev_priv(ndev);
1446 netif_stop_queue(ndev);
1447 napi_disable(&priv->napi);
1448 xcan_chip_stop(ndev);
1449 free_irq(ndev->irq, ndev);
1452 can_led_event(ndev, CAN_LED_EVENT_STOP);
1453 pm_runtime_put(priv->dev);
1459 * xcan_get_berr_counter - error counter routine
1460 * @ndev: Pointer to net_device structure
1461 * @bec: Pointer to can_berr_counter structure
1463 * This is the driver error counter routine.
1464 * Return: 0 on success and failure value on error
1466 static int xcan_get_berr_counter(const struct net_device *ndev,
1467 struct can_berr_counter *bec)
1469 struct xcan_priv *priv = netdev_priv(ndev);
1472 ret = pm_runtime_get_sync(priv->dev);
1474 netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
1479 bec->txerr = priv->read_reg(priv, XCAN_ECR_OFFSET) & XCAN_ECR_TEC_MASK;
1480 bec->rxerr = ((priv->read_reg(priv, XCAN_ECR_OFFSET) &
1481 XCAN_ECR_REC_MASK) >> XCAN_ESR_REC_SHIFT);
1483 pm_runtime_put(priv->dev);
1488 static const struct net_device_ops xcan_netdev_ops = {
1489 .ndo_open = xcan_open,
1490 .ndo_stop = xcan_close,
1491 .ndo_start_xmit = xcan_start_xmit,
1492 .ndo_change_mtu = can_change_mtu,
1496 * xcan_suspend - Suspend method for the driver
1497 * @dev: Address of the device structure
1499 * Put the driver into low power mode.
1500 * Return: 0 on success and failure value on error
1502 static int __maybe_unused xcan_suspend(struct device *dev)
1504 struct net_device *ndev = dev_get_drvdata(dev);
1506 if (netif_running(ndev)) {
1507 netif_stop_queue(ndev);
1508 netif_device_detach(ndev);
1509 xcan_chip_stop(ndev);
1512 return pm_runtime_force_suspend(dev);
1516 * xcan_resume - Resume from suspend
1517 * @dev: Address of the device structure
1519 * Resume operation after suspend.
1520 * Return: 0 on success and failure value on error
1522 static int __maybe_unused xcan_resume(struct device *dev)
1524 struct net_device *ndev = dev_get_drvdata(dev);
1527 ret = pm_runtime_force_resume(dev);
1529 dev_err(dev, "pm_runtime_force_resume failed on resume\n");
1533 if (netif_running(ndev)) {
1534 ret = xcan_chip_start(ndev);
1536 dev_err(dev, "xcan_chip_start failed on resume\n");
1540 netif_device_attach(ndev);
1541 netif_start_queue(ndev);
1548 * xcan_runtime_suspend - Runtime suspend method for the driver
1549 * @dev: Address of the device structure
1551 * Put the driver into low power mode.
1554 static int __maybe_unused xcan_runtime_suspend(struct device *dev)
1556 struct net_device *ndev = dev_get_drvdata(dev);
1557 struct xcan_priv *priv = netdev_priv(ndev);
1559 clk_disable_unprepare(priv->bus_clk);
1560 clk_disable_unprepare(priv->can_clk);
1566 * xcan_runtime_resume - Runtime resume from suspend
1567 * @dev: Address of the device structure
1569 * Resume operation after suspend.
1570 * Return: 0 on success and failure value on error
1572 static int __maybe_unused xcan_runtime_resume(struct device *dev)
1574 struct net_device *ndev = dev_get_drvdata(dev);
1575 struct xcan_priv *priv = netdev_priv(ndev);
1578 ret = clk_prepare_enable(priv->bus_clk);
1580 dev_err(dev, "Cannot enable clock.\n");
1583 ret = clk_prepare_enable(priv->can_clk);
1585 dev_err(dev, "Cannot enable clock.\n");
1586 clk_disable_unprepare(priv->bus_clk);
1593 static const struct dev_pm_ops xcan_dev_pm_ops = {
1594 SET_SYSTEM_SLEEP_PM_OPS(xcan_suspend, xcan_resume)
1595 SET_RUNTIME_PM_OPS(xcan_runtime_suspend, xcan_runtime_resume, NULL)
1598 static const struct xcan_devtype_data xcan_zynq_data = {
1599 .cantype = XZYNQ_CANPS,
1600 .flags = XCAN_FLAG_TXFEMP,
1601 .bittiming_const = &xcan_bittiming_const,
1602 .btr_ts2_shift = XCAN_BTR_TS2_SHIFT,
1603 .btr_sjw_shift = XCAN_BTR_SJW_SHIFT,
1604 .bus_clk_name = "pclk",
1607 static const struct xcan_devtype_data xcan_axi_data = {
1608 .cantype = XAXI_CAN,
1609 .bittiming_const = &xcan_bittiming_const,
1610 .btr_ts2_shift = XCAN_BTR_TS2_SHIFT,
1611 .btr_sjw_shift = XCAN_BTR_SJW_SHIFT,
1612 .bus_clk_name = "s_axi_aclk",
1615 static const struct xcan_devtype_data xcan_canfd_data = {
1616 .cantype = XAXI_CANFD,
1617 .flags = XCAN_FLAG_EXT_FILTERS |
1619 XCAN_FLAG_TX_MAILBOXES |
1620 XCAN_FLAG_RX_FIFO_MULTI,
1621 .bittiming_const = &xcan_bittiming_const_canfd,
1622 .btr_ts2_shift = XCAN_BTR_TS2_SHIFT_CANFD,
1623 .btr_sjw_shift = XCAN_BTR_SJW_SHIFT_CANFD,
1624 .bus_clk_name = "s_axi_aclk",
1627 static const struct xcan_devtype_data xcan_canfd2_data = {
1628 .cantype = XAXI_CANFD_2_0,
1629 .flags = XCAN_FLAG_EXT_FILTERS |
1631 XCAN_FLAG_TX_MAILBOXES |
1633 XCAN_FLAG_RX_FIFO_MULTI,
1634 .bittiming_const = &xcan_bittiming_const_canfd2,
1635 .btr_ts2_shift = XCAN_BTR_TS2_SHIFT_CANFD,
1636 .btr_sjw_shift = XCAN_BTR_SJW_SHIFT_CANFD,
1637 .bus_clk_name = "s_axi_aclk",
1640 /* Match table for OF platform binding */
1641 static const struct of_device_id xcan_of_match[] = {
1642 { .compatible = "xlnx,zynq-can-1.0", .data = &xcan_zynq_data },
1643 { .compatible = "xlnx,axi-can-1.00.a", .data = &xcan_axi_data },
1644 { .compatible = "xlnx,canfd-1.0", .data = &xcan_canfd_data },
1645 { .compatible = "xlnx,canfd-2.0", .data = &xcan_canfd2_data },
1646 { /* end of list */ },
1648 MODULE_DEVICE_TABLE(of, xcan_of_match);
1651 * xcan_probe - Platform registration call
1652 * @pdev: Handle to the platform device structure
1654 * This function does all the memory allocation and registration for the CAN
1657 * Return: 0 on success and failure value on error
1659 static int xcan_probe(struct platform_device *pdev)
1661 struct net_device *ndev;
1662 struct xcan_priv *priv;
1663 const struct of_device_id *of_id;
1664 const struct xcan_devtype_data *devtype = &xcan_axi_data;
1668 int hw_tx_max, hw_rx_max;
1669 const char *hw_tx_max_property;
1671 /* Get the virtual base address for the device */
1672 addr = devm_platform_ioremap_resource(pdev, 0);
1674 ret = PTR_ERR(addr);
1678 of_id = of_match_device(xcan_of_match, &pdev->dev);
1679 if (of_id && of_id->data)
1680 devtype = of_id->data;
1682 hw_tx_max_property = devtype->flags & XCAN_FLAG_TX_MAILBOXES ?
1683 "tx-mailbox-count" : "tx-fifo-depth";
1685 ret = of_property_read_u32(pdev->dev.of_node, hw_tx_max_property,
1688 dev_err(&pdev->dev, "missing %s property\n",
1689 hw_tx_max_property);
1693 ret = of_property_read_u32(pdev->dev.of_node, "rx-fifo-depth",
1697 "missing rx-fifo-depth property (mailbox mode is not supported)\n");
1703 * There is no way to directly figure out how many frames have been
1704 * sent when the TXOK interrupt is processed. If TXFEMP
1705 * is supported, we can have 2 frames in the FIFO and use TXFEMP
1706 * to determine if 1 or 2 frames have been sent.
1707 * Theoretically we should be able to use TXFWMEMP to determine up
1708 * to 3 frames, but it seems that after putting a second frame in the
1709 * FIFO, with watermark at 2 frames, it can happen that TXFWMEMP (less
1710 * than 2 frames in FIFO) is set anyway with no TXOK (a frame was
1711 * sent), which is not a sensible state - possibly TXFWMEMP is not
1712 * completely synchronized with the rest of the bits?
1714 * With TX mailboxes:
1716 * HW sends frames in CAN ID priority order. To preserve FIFO ordering
1717 * we submit frames one at a time.
1719 if (!(devtype->flags & XCAN_FLAG_TX_MAILBOXES) &&
1720 (devtype->flags & XCAN_FLAG_TXFEMP))
1721 tx_max = min(hw_tx_max, 2);
1727 /* Create a CAN device instance */
1728 ndev = alloc_candev(sizeof(struct xcan_priv), tx_max);
1732 priv = netdev_priv(ndev);
1733 priv->dev = &pdev->dev;
1734 priv->can.bittiming_const = devtype->bittiming_const;
1735 priv->can.do_set_mode = xcan_do_set_mode;
1736 priv->can.do_get_berr_counter = xcan_get_berr_counter;
1737 priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
1738 CAN_CTRLMODE_BERR_REPORTING;
1740 if (devtype->cantype == XAXI_CANFD)
1741 priv->can.data_bittiming_const =
1742 &xcan_data_bittiming_const_canfd;
1744 if (devtype->cantype == XAXI_CANFD_2_0)
1745 priv->can.data_bittiming_const =
1746 &xcan_data_bittiming_const_canfd2;
1748 if (devtype->cantype == XAXI_CANFD ||
1749 devtype->cantype == XAXI_CANFD_2_0)
1750 priv->can.ctrlmode_supported |= CAN_CTRLMODE_FD;
1752 priv->reg_base = addr;
1753 priv->tx_max = tx_max;
1754 priv->devtype = *devtype;
1755 spin_lock_init(&priv->tx_lock);
1757 /* Get IRQ for the device */
1758 ndev->irq = platform_get_irq(pdev, 0);
1759 ndev->flags |= IFF_ECHO; /* We support local echo */
1761 platform_set_drvdata(pdev, ndev);
1762 SET_NETDEV_DEV(ndev, &pdev->dev);
1763 ndev->netdev_ops = &xcan_netdev_ops;
1765 /* Getting the CAN can_clk info */
1766 priv->can_clk = devm_clk_get(&pdev->dev, "can_clk");
1767 if (IS_ERR(priv->can_clk)) {
1768 if (PTR_ERR(priv->can_clk) != -EPROBE_DEFER)
1769 dev_err(&pdev->dev, "Device clock not found.\n");
1770 ret = PTR_ERR(priv->can_clk);
1774 priv->bus_clk = devm_clk_get(&pdev->dev, devtype->bus_clk_name);
1775 if (IS_ERR(priv->bus_clk)) {
1776 if (PTR_ERR(priv->bus_clk) != -EPROBE_DEFER)
1777 dev_err(&pdev->dev, "bus clock not found\n");
1778 ret = PTR_ERR(priv->bus_clk);
1782 priv->write_reg = xcan_write_reg_le;
1783 priv->read_reg = xcan_read_reg_le;
1785 pm_runtime_enable(&pdev->dev);
1786 ret = pm_runtime_get_sync(&pdev->dev);
1788 netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
1793 if (priv->read_reg(priv, XCAN_SR_OFFSET) != XCAN_SR_CONFIG_MASK) {
1794 priv->write_reg = xcan_write_reg_be;
1795 priv->read_reg = xcan_read_reg_be;
1798 priv->can.clock.freq = clk_get_rate(priv->can_clk);
1800 netif_napi_add(ndev, &priv->napi, xcan_rx_poll, rx_max);
1802 ret = register_candev(ndev);
1804 dev_err(&pdev->dev, "fail to register failed (err=%d)\n", ret);
1805 goto err_disableclks;
1808 devm_can_led_init(ndev);
1810 pm_runtime_put(&pdev->dev);
1812 netdev_dbg(ndev, "reg_base=0x%p irq=%d clock=%d, tx buffers: actual %d, using %d\n",
1813 priv->reg_base, ndev->irq, priv->can.clock.freq,
1814 hw_tx_max, priv->tx_max);
1819 pm_runtime_put(priv->dev);
1821 pm_runtime_disable(&pdev->dev);
1829 * xcan_remove - Unregister the device after releasing the resources
1830 * @pdev: Handle to the platform device structure
1832 * This function frees all the resources allocated to the device.
1835 static int xcan_remove(struct platform_device *pdev)
1837 struct net_device *ndev = platform_get_drvdata(pdev);
1838 struct xcan_priv *priv = netdev_priv(ndev);
1840 unregister_candev(ndev);
1841 pm_runtime_disable(&pdev->dev);
1842 netif_napi_del(&priv->napi);
1848 static struct platform_driver xcan_driver = {
1849 .probe = xcan_probe,
1850 .remove = xcan_remove,
1852 .name = DRIVER_NAME,
1853 .pm = &xcan_dev_pm_ops,
1854 .of_match_table = xcan_of_match,
1858 module_platform_driver(xcan_driver);
1860 MODULE_LICENSE("GPL");
1861 MODULE_AUTHOR("Xilinx Inc");
1862 MODULE_DESCRIPTION("Xilinx CAN interface");