1// SPDX-License-Identifier: GPL-2.0-or-later
2/* Xilinx CAN device driver
3 *
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
7 *
8 * Description:
9 * This driver is developed for Axi CAN IP and for Zynq CANPS Controller.
10 */
11
12#include <linux/clk.h>
13#include <linux/errno.h>
14#include <linux/init.h>
15#include <linux/interrupt.h>
16#include <linux/io.h>
17#include <linux/kernel.h>
18#include <linux/module.h>
19#include <linux/netdevice.h>
20#include <linux/of.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>
31
32#define DRIVER_NAME	"xilinx_can"
33
34/* CAN registers set */
35enum xcan_reg {
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 */
46
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 */
51
52	/* only on CAN FD cores */
53	XCAN_F_BRPR_OFFSET	= 0x088, /* Data Phase Baud Rate
54					  * Prescalar
55					  */
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 */
63	XCAN_AFR_2_MASK_OFFSET	= 0x0A00, /* Acceptance Filter MASK */
64	XCAN_AFR_2_ID_OFFSET	= 0x0A04, /* Acceptance Filter ID */
65};
66
67#define XCAN_FRAME_ID_OFFSET(frame_base)	((frame_base) + 0x00)
68#define XCAN_FRAME_DLC_OFFSET(frame_base)	((frame_base) + 0x04)
69#define XCAN_FRAME_DW1_OFFSET(frame_base)	((frame_base) + 0x08)
70#define XCAN_FRAME_DW2_OFFSET(frame_base)	((frame_base) + 0x0C)
71#define XCANFD_FRAME_DW_OFFSET(frame_base)	((frame_base) + 0x08)
72
73#define XCAN_CANFD_FRAME_SIZE		0x48
74#define XCAN_TXMSG_FRAME_OFFSET(n)	(XCAN_TXMSG_BASE_OFFSET + \
75					 XCAN_CANFD_FRAME_SIZE * (n))
76#define XCAN_RXMSG_FRAME_OFFSET(n)	(XCAN_RXMSG_BASE_OFFSET + \
77					 XCAN_CANFD_FRAME_SIZE * (n))
78#define XCAN_RXMSG_2_FRAME_OFFSET(n)	(XCAN_RXMSG_2_BASE_OFFSET + \
79					 XCAN_CANFD_FRAME_SIZE * (n))
80
81/* the single TX mailbox used by this driver on CAN FD HW */
82#define XCAN_TX_MAILBOX_IDX		0
83
84/* CAN register bit masks - XCAN_<REG>_<BIT>_MASK */
85#define XCAN_SRR_CEN_MASK		0x00000002 /* CAN enable */
86#define XCAN_SRR_RESET_MASK		0x00000001 /* Soft Reset the CAN core */
87#define XCAN_MSR_LBACK_MASK		0x00000002 /* Loop back mode select */
88#define XCAN_MSR_SLEEP_MASK		0x00000001 /* Sleep mode select */
89#define XCAN_BRPR_BRP_MASK		0x000000FF /* Baud rate prescaler */
90#define XCAN_BTR_SJW_MASK		0x00000180 /* Synchronous jump width */
91#define XCAN_BTR_TS2_MASK		0x00000070 /* Time segment 2 */
92#define XCAN_BTR_TS1_MASK		0x0000000F /* Time segment 1 */
93#define XCAN_BTR_SJW_MASK_CANFD		0x000F0000 /* Synchronous jump width */
94#define XCAN_BTR_TS2_MASK_CANFD		0x00000F00 /* Time segment 2 */
95#define XCAN_BTR_TS1_MASK_CANFD		0x0000003F /* Time segment 1 */
96#define XCAN_ECR_REC_MASK		0x0000FF00 /* Receive error counter */
97#define XCAN_ECR_TEC_MASK		0x000000FF /* Transmit error counter */
98#define XCAN_ESR_ACKER_MASK		0x00000010 /* ACK error */
99#define XCAN_ESR_BERR_MASK		0x00000008 /* Bit error */
100#define XCAN_ESR_STER_MASK		0x00000004 /* Stuff error */
101#define XCAN_ESR_FMER_MASK		0x00000002 /* Form error */
102#define XCAN_ESR_CRCER_MASK		0x00000001 /* CRC error */
103#define XCAN_SR_TXFLL_MASK		0x00000400 /* TX FIFO is full */
104#define XCAN_SR_ESTAT_MASK		0x00000180 /* Error status */
105#define XCAN_SR_ERRWRN_MASK		0x00000040 /* Error warning */
106#define XCAN_SR_NORMAL_MASK		0x00000008 /* Normal mode */
107#define XCAN_SR_LBACK_MASK		0x00000002 /* Loop back mode */
108#define XCAN_SR_CONFIG_MASK		0x00000001 /* Configuration mode */
109#define XCAN_IXR_RXMNF_MASK		0x00020000 /* RX match not finished */
110#define XCAN_IXR_TXFEMP_MASK		0x00004000 /* TX FIFO Empty */
111#define XCAN_IXR_WKUP_MASK		0x00000800 /* Wake up interrupt */
112#define XCAN_IXR_SLP_MASK		0x00000400 /* Sleep interrupt */
113#define XCAN_IXR_BSOFF_MASK		0x00000200 /* Bus off interrupt */
114#define XCAN_IXR_ERROR_MASK		0x00000100 /* Error interrupt */
115#define XCAN_IXR_RXNEMP_MASK		0x00000080 /* RX FIFO NotEmpty intr */
116#define XCAN_IXR_RXOFLW_MASK		0x00000040 /* RX FIFO Overflow intr */
117#define XCAN_IXR_RXOK_MASK		0x00000010 /* Message received intr */
118#define XCAN_IXR_TXFLL_MASK		0x00000004 /* Tx FIFO Full intr */
119#define XCAN_IXR_TXOK_MASK		0x00000002 /* TX successful intr */
120#define XCAN_IXR_ARBLST_MASK		0x00000001 /* Arbitration lost intr */
121#define XCAN_IDR_ID1_MASK		0xFFE00000 /* Standard msg identifier */
122#define XCAN_IDR_SRR_MASK		0x00100000 /* Substitute remote TXreq */
123#define XCAN_IDR_IDE_MASK		0x00080000 /* Identifier extension */
124#define XCAN_IDR_ID2_MASK		0x0007FFFE /* Extended message ident */
125#define XCAN_IDR_RTR_MASK		0x00000001 /* Remote TX request */
126#define XCAN_DLCR_DLC_MASK		0xF0000000 /* Data length code */
127#define XCAN_FSR_FL_MASK		0x00003F00 /* RX Fill Level */
128#define XCAN_2_FSR_FL_MASK		0x00007F00 /* RX Fill Level */
129#define XCAN_FSR_IRI_MASK		0x00000080 /* RX Increment Read Index */
130#define XCAN_FSR_RI_MASK		0x0000001F /* RX Read Index */
131#define XCAN_2_FSR_RI_MASK		0x0000003F /* RX Read Index */
132#define XCAN_DLCR_EDL_MASK		0x08000000 /* EDL Mask in DLC */
133#define XCAN_DLCR_BRS_MASK		0x04000000 /* BRS Mask in DLC */
134
135/* CAN register bit shift - XCAN_<REG>_<BIT>_SHIFT */
136#define XCAN_BTR_SJW_SHIFT		7  /* Synchronous jump width */
137#define XCAN_BTR_TS2_SHIFT		4  /* Time segment 2 */
138#define XCAN_BTR_SJW_SHIFT_CANFD	16 /* Synchronous jump width */
139#define XCAN_BTR_TS2_SHIFT_CANFD	8  /* Time segment 2 */
140#define XCAN_IDR_ID1_SHIFT		21 /* Standard Messg Identifier */
141#define XCAN_IDR_ID2_SHIFT		1  /* Extended Message Identifier */
142#define XCAN_DLCR_DLC_SHIFT		28 /* Data length code */
143#define XCAN_ESR_REC_SHIFT		8  /* Rx Error Count */
144
145/* CAN frame length constants */
146#define XCAN_FRAME_MAX_DATA_LEN		8
147#define XCANFD_DW_BYTES			4
148#define XCAN_TIMEOUT			(1 * HZ)
149
150/* TX-FIFO-empty interrupt available */
151#define XCAN_FLAG_TXFEMP	0x0001
152/* RX Match Not Finished interrupt available */
153#define XCAN_FLAG_RXMNF		0x0002
154/* Extended acceptance filters with control at 0xE0 */
155#define XCAN_FLAG_EXT_FILTERS	0x0004
156/* TX mailboxes instead of TX FIFO */
157#define XCAN_FLAG_TX_MAILBOXES	0x0008
158/* RX FIFO with each buffer in separate registers at 0x1100
159 * instead of the regular FIFO at 0x50
160 */
161#define XCAN_FLAG_RX_FIFO_MULTI	0x0010
162#define XCAN_FLAG_CANFD_2	0x0020
163
164enum xcan_ip_type {
165	XAXI_CAN = 0,
166	XZYNQ_CANPS,
167	XAXI_CANFD,
168	XAXI_CANFD_2_0,
169};
170
171struct xcan_devtype_data {
172	enum xcan_ip_type cantype;
173	unsigned int flags;
174	const struct can_bittiming_const *bittiming_const;
175	const char *bus_clk_name;
176	unsigned int btr_ts2_shift;
177	unsigned int btr_sjw_shift;
178};
179
180/**
181 * struct xcan_priv - This definition define CAN driver instance
182 * @can:			CAN private data structure.
183 * @tx_lock:			Lock for synchronizing TX interrupt handling
184 * @tx_head:			Tx CAN packets ready to send on the queue
185 * @tx_tail:			Tx CAN packets successfully sended on the queue
186 * @tx_max:			Maximum number packets the driver can send
187 * @napi:			NAPI structure
188 * @read_reg:			For reading data from CAN registers
189 * @write_reg:			For writing data to CAN registers
190 * @dev:			Network device data structure
191 * @reg_base:			Ioremapped address to registers
192 * @irq_flags:			For request_irq()
193 * @bus_clk:			Pointer to struct clk
194 * @can_clk:			Pointer to struct clk
195 * @devtype:			Device type specific constants
196 */
197struct xcan_priv {
198	struct can_priv can;
199	spinlock_t tx_lock; /* Lock for synchronizing TX interrupt handling */
200	unsigned int tx_head;
201	unsigned int tx_tail;
202	unsigned int tx_max;
203	struct napi_struct napi;
204	u32 (*read_reg)(const struct xcan_priv *priv, enum xcan_reg reg);
205	void (*write_reg)(const struct xcan_priv *priv, enum xcan_reg reg,
206			  u32 val);
207	struct device *dev;
208	void __iomem *reg_base;
209	unsigned long irq_flags;
210	struct clk *bus_clk;
211	struct clk *can_clk;
212	struct xcan_devtype_data devtype;
213};
214
215/* CAN Bittiming constants as per Xilinx CAN specs */
216static const struct can_bittiming_const xcan_bittiming_const = {
217	.name = DRIVER_NAME,
218	.tseg1_min = 1,
219	.tseg1_max = 16,
220	.tseg2_min = 1,
221	.tseg2_max = 8,
222	.sjw_max = 4,
223	.brp_min = 1,
224	.brp_max = 256,
225	.brp_inc = 1,
226};
227
228/* AXI CANFD Arbitration Bittiming constants as per AXI CANFD 1.0 spec */
229static const struct can_bittiming_const xcan_bittiming_const_canfd = {
230	.name = DRIVER_NAME,
231	.tseg1_min = 1,
232	.tseg1_max = 64,
233	.tseg2_min = 1,
234	.tseg2_max = 16,
235	.sjw_max = 16,
236	.brp_min = 1,
237	.brp_max = 256,
238	.brp_inc = 1,
239};
240
241/* AXI CANFD Data Bittiming constants as per AXI CANFD 1.0 specs */
242static const struct can_bittiming_const xcan_data_bittiming_const_canfd = {
243	.name = DRIVER_NAME,
244	.tseg1_min = 1,
245	.tseg1_max = 16,
246	.tseg2_min = 1,
247	.tseg2_max = 8,
248	.sjw_max = 8,
249	.brp_min = 1,
250	.brp_max = 256,
251	.brp_inc = 1,
252};
253
254/* AXI CANFD 2.0 Arbitration Bittiming constants as per AXI CANFD 2.0 spec */
255static const struct can_bittiming_const xcan_bittiming_const_canfd2 = {
256	.name = DRIVER_NAME,
257	.tseg1_min = 1,
258	.tseg1_max = 256,
259	.tseg2_min = 1,
260	.tseg2_max = 128,
261	.sjw_max = 128,
262	.brp_min = 1,
263	.brp_max = 256,
264	.brp_inc = 1,
265};
266
267/* AXI CANFD 2.0 Data Bittiming constants as per AXI CANFD 2.0 spec */
268static const struct can_bittiming_const xcan_data_bittiming_const_canfd2 = {
269	.name = DRIVER_NAME,
270	.tseg1_min = 1,
271	.tseg1_max = 32,
272	.tseg2_min = 1,
273	.tseg2_max = 16,
274	.sjw_max = 16,
275	.brp_min = 1,
276	.brp_max = 256,
277	.brp_inc = 1,
278};
279
280/**
281 * xcan_write_reg_le - Write a value to the device register little endian
282 * @priv:	Driver private data structure
283 * @reg:	Register offset
284 * @val:	Value to write at the Register offset
285 *
286 * Write data to the paricular CAN register
287 */
288static void xcan_write_reg_le(const struct xcan_priv *priv, enum xcan_reg reg,
289			      u32 val)
290{
291	iowrite32(val, priv->reg_base + reg);
292}
293
294/**
295 * xcan_read_reg_le - Read a value from the device register little endian
296 * @priv:	Driver private data structure
297 * @reg:	Register offset
298 *
299 * Read data from the particular CAN register
300 * Return: value read from the CAN register
301 */
302static u32 xcan_read_reg_le(const struct xcan_priv *priv, enum xcan_reg reg)
303{
304	return ioread32(priv->reg_base + reg);
305}
306
307/**
308 * xcan_write_reg_be - Write a value to the device register big endian
309 * @priv:	Driver private data structure
310 * @reg:	Register offset
311 * @val:	Value to write at the Register offset
312 *
313 * Write data to the paricular CAN register
314 */
315static void xcan_write_reg_be(const struct xcan_priv *priv, enum xcan_reg reg,
316			      u32 val)
317{
318	iowrite32be(val, priv->reg_base + reg);
319}
320
321/**
322 * xcan_read_reg_be - Read a value from the device register big endian
323 * @priv:	Driver private data structure
324 * @reg:	Register offset
325 *
326 * Read data from the particular CAN register
327 * Return: value read from the CAN register
328 */
329static u32 xcan_read_reg_be(const struct xcan_priv *priv, enum xcan_reg reg)
330{
331	return ioread32be(priv->reg_base + reg);
332}
333
334/**
335 * xcan_rx_int_mask - Get the mask for the receive interrupt
336 * @priv:	Driver private data structure
337 *
338 * Return: The receive interrupt mask used by the driver on this HW
339 */
340static u32 xcan_rx_int_mask(const struct xcan_priv *priv)
341{
342	/* RXNEMP is better suited for our use case as it cannot be cleared
343	 * while the FIFO is non-empty, but CAN FD HW does not have it
344	 */
345	if (priv->devtype.flags & XCAN_FLAG_RX_FIFO_MULTI)
346		return XCAN_IXR_RXOK_MASK;
347	else
348		return XCAN_IXR_RXNEMP_MASK;
349}
350
351/**
352 * set_reset_mode - Resets the CAN device mode
353 * @ndev:	Pointer to net_device structure
354 *
355 * This is the driver reset mode routine.The driver
356 * enters into configuration mode.
357 *
358 * Return: 0 on success and failure value on error
359 */
360static int set_reset_mode(struct net_device *ndev)
361{
362	struct xcan_priv *priv = netdev_priv(ndev);
363	unsigned long timeout;
364
365	priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK);
366
367	timeout = jiffies + XCAN_TIMEOUT;
368	while (!(priv->read_reg(priv, XCAN_SR_OFFSET) & XCAN_SR_CONFIG_MASK)) {
369		if (time_after(jiffies, timeout)) {
370			netdev_warn(ndev, "timed out for config mode\n");
371			return -ETIMEDOUT;
372		}
373		usleep_range(500, 10000);
374	}
375
376	/* reset clears FIFOs */
377	priv->tx_head = 0;
378	priv->tx_tail = 0;
379
380	return 0;
381}
382
383/**
384 * xcan_set_bittiming - CAN set bit timing routine
385 * @ndev:	Pointer to net_device structure
386 *
387 * This is the driver set bittiming  routine.
388 * Return: 0 on success and failure value on error
389 */
390static int xcan_set_bittiming(struct net_device *ndev)
391{
392	struct xcan_priv *priv = netdev_priv(ndev);
393	struct can_bittiming *bt = &priv->can.bittiming;
394	struct can_bittiming *dbt = &priv->can.data_bittiming;
395	u32 btr0, btr1;
396	u32 is_config_mode;
397
398	/* Check whether Xilinx CAN is in configuration mode.
399	 * It cannot set bit timing if Xilinx CAN is not in configuration mode.
400	 */
401	is_config_mode = priv->read_reg(priv, XCAN_SR_OFFSET) &
402				XCAN_SR_CONFIG_MASK;
403	if (!is_config_mode) {
404		netdev_alert(ndev,
405			     "BUG! Cannot set bittiming - CAN is not in config mode\n");
406		return -EPERM;
407	}
408
409	/* Setting Baud Rate prescalar value in BRPR Register */
410	btr0 = (bt->brp - 1);
411
412	/* Setting Time Segment 1 in BTR Register */
413	btr1 = (bt->prop_seg + bt->phase_seg1 - 1);
414
415	/* Setting Time Segment 2 in BTR Register */
416	btr1 |= (bt->phase_seg2 - 1) << priv->devtype.btr_ts2_shift;
417
418	/* Setting Synchronous jump width in BTR Register */
419	btr1 |= (bt->sjw - 1) << priv->devtype.btr_sjw_shift;
420
421	priv->write_reg(priv, XCAN_BRPR_OFFSET, btr0);
422	priv->write_reg(priv, XCAN_BTR_OFFSET, btr1);
423
424	if (priv->devtype.cantype == XAXI_CANFD ||
425	    priv->devtype.cantype == XAXI_CANFD_2_0) {
426		/* Setting Baud Rate prescalar value in F_BRPR Register */
427		btr0 = dbt->brp - 1;
428
429		/* Setting Time Segment 1 in BTR Register */
430		btr1 = dbt->prop_seg + dbt->phase_seg1 - 1;
431
432		/* Setting Time Segment 2 in BTR Register */
433		btr1 |= (dbt->phase_seg2 - 1) << priv->devtype.btr_ts2_shift;
434
435		/* Setting Synchronous jump width in BTR Register */
436		btr1 |= (dbt->sjw - 1) << priv->devtype.btr_sjw_shift;
437
438		priv->write_reg(priv, XCAN_F_BRPR_OFFSET, btr0);
439		priv->write_reg(priv, XCAN_F_BTR_OFFSET, btr1);
440	}
441
442	netdev_dbg(ndev, "BRPR=0x%08x, BTR=0x%08x\n",
443		   priv->read_reg(priv, XCAN_BRPR_OFFSET),
444		   priv->read_reg(priv, XCAN_BTR_OFFSET));
445
446	return 0;
447}
448
449/**
450 * xcan_chip_start - This the drivers start routine
451 * @ndev:	Pointer to net_device structure
452 *
453 * This is the drivers start routine.
454 * Based on the State of the CAN device it puts
455 * the CAN device into a proper mode.
456 *
457 * Return: 0 on success and failure value on error
458 */
459static int xcan_chip_start(struct net_device *ndev)
460{
461	struct xcan_priv *priv = netdev_priv(ndev);
462	u32 reg_msr;
463	int err;
464	u32 ier;
465
466	/* Check if it is in reset mode */
467	err = set_reset_mode(ndev);
468	if (err < 0)
469		return err;
470
471	err = xcan_set_bittiming(ndev);
472	if (err < 0)
473		return err;
474
475	/* Enable interrupts
476	 *
477	 * We enable the ERROR interrupt even with
478	 * CAN_CTRLMODE_BERR_REPORTING disabled as there is no
479	 * dedicated interrupt for a state change to
480	 * ERROR_WARNING/ERROR_PASSIVE.
481	 */
482	ier = XCAN_IXR_TXOK_MASK | XCAN_IXR_BSOFF_MASK |
483		XCAN_IXR_WKUP_MASK | XCAN_IXR_SLP_MASK |
484		XCAN_IXR_ERROR_MASK | XCAN_IXR_RXOFLW_MASK |
485		XCAN_IXR_ARBLST_MASK | xcan_rx_int_mask(priv);
486
487	if (priv->devtype.flags & XCAN_FLAG_RXMNF)
488		ier |= XCAN_IXR_RXMNF_MASK;
489
490	priv->write_reg(priv, XCAN_IER_OFFSET, ier);
491
492	/* Check whether it is loopback mode or normal mode  */
493	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
494		reg_msr = XCAN_MSR_LBACK_MASK;
495	else
496		reg_msr = 0x0;
497
498	/* enable the first extended filter, if any, as cores with extended
499	 * filtering default to non-receipt if all filters are disabled
500	 */
501	if (priv->devtype.flags & XCAN_FLAG_EXT_FILTERS)
502		priv->write_reg(priv, XCAN_AFR_EXT_OFFSET, 0x00000001);
503
504	priv->write_reg(priv, XCAN_MSR_OFFSET, reg_msr);
505	priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_CEN_MASK);
506
507	netdev_dbg(ndev, "status:#x%08x\n",
508		   priv->read_reg(priv, XCAN_SR_OFFSET));
509
510	priv->can.state = CAN_STATE_ERROR_ACTIVE;
511	return 0;
512}
513
514/**
515 * xcan_do_set_mode - This sets the mode of the driver
516 * @ndev:	Pointer to net_device structure
517 * @mode:	Tells the mode of the driver
518 *
519 * This check the drivers state and calls the
520 * the corresponding modes to set.
521 *
522 * Return: 0 on success and failure value on error
523 */
524static int xcan_do_set_mode(struct net_device *ndev, enum can_mode mode)
525{
526	int ret;
527
528	switch (mode) {
529	case CAN_MODE_START:
530		ret = xcan_chip_start(ndev);
531		if (ret < 0) {
532			netdev_err(ndev, "xcan_chip_start failed!\n");
533			return ret;
534		}
535		netif_wake_queue(ndev);
536		break;
537	default:
538		ret = -EOPNOTSUPP;
539		break;
540	}
541
542	return ret;
543}
544
545/**
546 * xcan_write_frame - Write a frame to HW
547 * @ndev:		Pointer to net_device structure
548 * @skb:		sk_buff pointer that contains data to be Txed
549 * @frame_offset:	Register offset to write the frame to
550 */
551static void xcan_write_frame(struct net_device *ndev, struct sk_buff *skb,
552			     int frame_offset)
553{
554	u32 id, dlc, data[2] = {0, 0};
555	struct canfd_frame *cf = (struct canfd_frame *)skb->data;
556	u32 ramoff, dwindex = 0, i;
557	struct xcan_priv *priv = netdev_priv(ndev);
558
559	/* Watch carefully on the bit sequence */
560	if (cf->can_id & CAN_EFF_FLAG) {
561		/* Extended CAN ID format */
562		id = ((cf->can_id & CAN_EFF_MASK) << XCAN_IDR_ID2_SHIFT) &
563			XCAN_IDR_ID2_MASK;
564		id |= (((cf->can_id & CAN_EFF_MASK) >>
565			(CAN_EFF_ID_BITS - CAN_SFF_ID_BITS)) <<
566			XCAN_IDR_ID1_SHIFT) & XCAN_IDR_ID1_MASK;
567
568		/* The substibute remote TX request bit should be "1"
569		 * for extended frames as in the Xilinx CAN datasheet
570		 */
571		id |= XCAN_IDR_IDE_MASK | XCAN_IDR_SRR_MASK;
572
573		if (cf->can_id & CAN_RTR_FLAG)
574			/* Extended frames remote TX request */
575			id |= XCAN_IDR_RTR_MASK;
576	} else {
577		/* Standard CAN ID format */
578		id = ((cf->can_id & CAN_SFF_MASK) << XCAN_IDR_ID1_SHIFT) &
579			XCAN_IDR_ID1_MASK;
580
581		if (cf->can_id & CAN_RTR_FLAG)
582			/* Standard frames remote TX request */
583			id |= XCAN_IDR_SRR_MASK;
584	}
585
586	dlc = can_len2dlc(cf->len) << XCAN_DLCR_DLC_SHIFT;
587	if (can_is_canfd_skb(skb)) {
588		if (cf->flags & CANFD_BRS)
589			dlc |= XCAN_DLCR_BRS_MASK;
590		dlc |= XCAN_DLCR_EDL_MASK;
591	}
592
593	if (!(priv->devtype.flags & XCAN_FLAG_TX_MAILBOXES) &&
594	    (priv->devtype.flags & XCAN_FLAG_TXFEMP))
595		can_put_echo_skb(skb, ndev, priv->tx_head % priv->tx_max);
596	else
597		can_put_echo_skb(skb, ndev, 0);
598
599	priv->tx_head++;
600
601	priv->write_reg(priv, XCAN_FRAME_ID_OFFSET(frame_offset), id);
602	/* If the CAN frame is RTR frame this write triggers transmission
603	 * (not on CAN FD)
604	 */
605	priv->write_reg(priv, XCAN_FRAME_DLC_OFFSET(frame_offset), dlc);
606	if (priv->devtype.cantype == XAXI_CANFD ||
607	    priv->devtype.cantype == XAXI_CANFD_2_0) {
608		for (i = 0; i < cf->len; i += 4) {
609			ramoff = XCANFD_FRAME_DW_OFFSET(frame_offset) +
610					(dwindex * XCANFD_DW_BYTES);
611			priv->write_reg(priv, ramoff,
612					be32_to_cpup((__be32 *)(cf->data + i)));
613			dwindex++;
614		}
615	} else {
616		if (cf->len > 0)
617			data[0] = be32_to_cpup((__be32 *)(cf->data + 0));
618		if (cf->len > 4)
619			data[1] = be32_to_cpup((__be32 *)(cf->data + 4));
620
621		if (!(cf->can_id & CAN_RTR_FLAG)) {
622			priv->write_reg(priv,
623					XCAN_FRAME_DW1_OFFSET(frame_offset),
624					data[0]);
625			/* If the CAN frame is Standard/Extended frame this
626			 * write triggers transmission (not on CAN FD)
627			 */
628			priv->write_reg(priv,
629					XCAN_FRAME_DW2_OFFSET(frame_offset),
630					data[1]);
631		}
632	}
633}
634
635/**
636 * xcan_start_xmit_fifo - Starts the transmission (FIFO mode)
637 * @skb:	sk_buff pointer that contains data to be Txed
638 * @ndev:	Pointer to net_device structure
639 *
640 * Return: 0 on success, -ENOSPC if FIFO is full.
641 */
642static int xcan_start_xmit_fifo(struct sk_buff *skb, struct net_device *ndev)
643{
644	struct xcan_priv *priv = netdev_priv(ndev);
645	unsigned long flags;
646
647	/* Check if the TX buffer is full */
648	if (unlikely(priv->read_reg(priv, XCAN_SR_OFFSET) &
649			XCAN_SR_TXFLL_MASK))
650		return -ENOSPC;
651
652	spin_lock_irqsave(&priv->tx_lock, flags);
653
654	xcan_write_frame(ndev, skb, XCAN_TXFIFO_OFFSET);
655
656	/* Clear TX-FIFO-empty interrupt for xcan_tx_interrupt() */
657	if (priv->tx_max > 1)
658		priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_TXFEMP_MASK);
659
660	/* Check if the TX buffer is full */
661	if ((priv->tx_head - priv->tx_tail) == priv->tx_max)
662		netif_stop_queue(ndev);
663
664	spin_unlock_irqrestore(&priv->tx_lock, flags);
665
666	return 0;
667}
668
669/**
670 * xcan_start_xmit_mailbox - Starts the transmission (mailbox mode)
671 * @skb:	sk_buff pointer that contains data to be Txed
672 * @ndev:	Pointer to net_device structure
673 *
674 * Return: 0 on success, -ENOSPC if there is no space
675 */
676static int xcan_start_xmit_mailbox(struct sk_buff *skb, struct net_device *ndev)
677{
678	struct xcan_priv *priv = netdev_priv(ndev);
679	unsigned long flags;
680
681	if (unlikely(priv->read_reg(priv, XCAN_TRR_OFFSET) &
682		     BIT(XCAN_TX_MAILBOX_IDX)))
683		return -ENOSPC;
684
685	spin_lock_irqsave(&priv->tx_lock, flags);
686
687	xcan_write_frame(ndev, skb,
688			 XCAN_TXMSG_FRAME_OFFSET(XCAN_TX_MAILBOX_IDX));
689
690	/* Mark buffer as ready for transmit */
691	priv->write_reg(priv, XCAN_TRR_OFFSET, BIT(XCAN_TX_MAILBOX_IDX));
692
693	netif_stop_queue(ndev);
694
695	spin_unlock_irqrestore(&priv->tx_lock, flags);
696
697	return 0;
698}
699
700/**
701 * xcan_start_xmit - Starts the transmission
702 * @skb:	sk_buff pointer that contains data to be Txed
703 * @ndev:	Pointer to net_device structure
704 *
705 * This function is invoked from upper layers to initiate transmission.
706 *
707 * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY when the tx queue is full
708 */
709static netdev_tx_t xcan_start_xmit(struct sk_buff *skb, struct net_device *ndev)
710{
711	struct xcan_priv *priv = netdev_priv(ndev);
712	int ret;
713
714	if (can_dropped_invalid_skb(ndev, skb))
715		return NETDEV_TX_OK;
716
717	if (priv->devtype.flags & XCAN_FLAG_TX_MAILBOXES)
718		ret = xcan_start_xmit_mailbox(skb, ndev);
719	else
720		ret = xcan_start_xmit_fifo(skb, ndev);
721
722	if (ret < 0) {
723		netdev_err(ndev, "BUG!, TX full when queue awake!\n");
724		netif_stop_queue(ndev);
725		return NETDEV_TX_BUSY;
726	}
727
728	return NETDEV_TX_OK;
729}
730
731/**
732 * xcan_rx -  Is called from CAN isr to complete the received
733 *		frame  processing
734 * @ndev:	Pointer to net_device structure
735 * @frame_base:	Register offset to the frame to be read
736 *
737 * This function is invoked from the CAN isr(poll) to process the Rx frames. It
738 * does minimal processing and invokes "netif_receive_skb" to complete further
739 * processing.
740 * Return: 1 on success and 0 on failure.
741 */
742static int xcan_rx(struct net_device *ndev, int frame_base)
743{
744	struct xcan_priv *priv = netdev_priv(ndev);
745	struct net_device_stats *stats = &ndev->stats;
746	struct can_frame *cf;
747	struct sk_buff *skb;
748	u32 id_xcan, dlc, data[2] = {0, 0};
749
750	skb = alloc_can_skb(ndev, &cf);
751	if (unlikely(!skb)) {
752		stats->rx_dropped++;
753		return 0;
754	}
755
756	/* Read a frame from Xilinx zynq CANPS */
757	id_xcan = priv->read_reg(priv, XCAN_FRAME_ID_OFFSET(frame_base));
758	dlc = priv->read_reg(priv, XCAN_FRAME_DLC_OFFSET(frame_base)) >>
759				   XCAN_DLCR_DLC_SHIFT;
760
761	/* Change Xilinx CAN data length format to socketCAN data format */
762	cf->can_dlc = get_can_dlc(dlc);
763
764	/* Change Xilinx CAN ID format to socketCAN ID format */
765	if (id_xcan & XCAN_IDR_IDE_MASK) {
766		/* The received frame is an Extended format frame */
767		cf->can_id = (id_xcan & XCAN_IDR_ID1_MASK) >> 3;
768		cf->can_id |= (id_xcan & XCAN_IDR_ID2_MASK) >>
769				XCAN_IDR_ID2_SHIFT;
770		cf->can_id |= CAN_EFF_FLAG;
771		if (id_xcan & XCAN_IDR_RTR_MASK)
772			cf->can_id |= CAN_RTR_FLAG;
773	} else {
774		/* The received frame is a standard format frame */
775		cf->can_id = (id_xcan & XCAN_IDR_ID1_MASK) >>
776				XCAN_IDR_ID1_SHIFT;
777		if (id_xcan & XCAN_IDR_SRR_MASK)
778			cf->can_id |= CAN_RTR_FLAG;
779	}
780
781	/* DW1/DW2 must always be read to remove message from RXFIFO */
782	data[0] = priv->read_reg(priv, XCAN_FRAME_DW1_OFFSET(frame_base));
783	data[1] = priv->read_reg(priv, XCAN_FRAME_DW2_OFFSET(frame_base));
784
785	if (!(cf->can_id & CAN_RTR_FLAG)) {
786		/* Change Xilinx CAN data format to socketCAN data format */
787		if (cf->can_dlc > 0)
788			*(__be32 *)(cf->data) = cpu_to_be32(data[0]);
789		if (cf->can_dlc > 4)
790			*(__be32 *)(cf->data + 4) = cpu_to_be32(data[1]);
791	}
792
793	stats->rx_bytes += cf->can_dlc;
794	stats->rx_packets++;
795	netif_receive_skb(skb);
796
797	return 1;
798}
799
800/**
801 * xcanfd_rx -  Is called from CAN isr to complete the received
802 *		frame  processing
803 * @ndev:	Pointer to net_device structure
804 * @frame_base:	Register offset to the frame to be read
805 *
806 * This function is invoked from the CAN isr(poll) to process the Rx frames. It
807 * does minimal processing and invokes "netif_receive_skb" to complete further
808 * processing.
809 * Return: 1 on success and 0 on failure.
810 */
811static int xcanfd_rx(struct net_device *ndev, int frame_base)
812{
813	struct xcan_priv *priv = netdev_priv(ndev);
814	struct net_device_stats *stats = &ndev->stats;
815	struct canfd_frame *cf;
816	struct sk_buff *skb;
817	u32 id_xcan, dlc, data[2] = {0, 0}, dwindex = 0, i, dw_offset;
818
819	id_xcan = priv->read_reg(priv, XCAN_FRAME_ID_OFFSET(frame_base));
820	dlc = priv->read_reg(priv, XCAN_FRAME_DLC_OFFSET(frame_base));
821	if (dlc & XCAN_DLCR_EDL_MASK)
822		skb = alloc_canfd_skb(ndev, &cf);
823	else
824		skb = alloc_can_skb(ndev, (struct can_frame **)&cf);
825
826	if (unlikely(!skb)) {
827		stats->rx_dropped++;
828		return 0;
829	}
830
831	/* Change Xilinx CANFD data length format to socketCAN data
832	 * format
833	 */
834	if (dlc & XCAN_DLCR_EDL_MASK)
835		cf->len = can_dlc2len((dlc & XCAN_DLCR_DLC_MASK) >>
836				  XCAN_DLCR_DLC_SHIFT);
837	else
838		cf->len = get_can_dlc((dlc & XCAN_DLCR_DLC_MASK) >>
839					  XCAN_DLCR_DLC_SHIFT);
840
841	/* Change Xilinx CAN ID format to socketCAN ID format */
842	if (id_xcan & XCAN_IDR_IDE_MASK) {
843		/* The received frame is an Extended format frame */
844		cf->can_id = (id_xcan & XCAN_IDR_ID1_MASK) >> 3;
845		cf->can_id |= (id_xcan & XCAN_IDR_ID2_MASK) >>
846				XCAN_IDR_ID2_SHIFT;
847		cf->can_id |= CAN_EFF_FLAG;
848		if (id_xcan & XCAN_IDR_RTR_MASK)
849			cf->can_id |= CAN_RTR_FLAG;
850	} else {
851		/* The received frame is a standard format frame */
852		cf->can_id = (id_xcan & XCAN_IDR_ID1_MASK) >>
853				XCAN_IDR_ID1_SHIFT;
854		if (!(dlc & XCAN_DLCR_EDL_MASK) && (id_xcan &
855					XCAN_IDR_SRR_MASK))
856			cf->can_id |= CAN_RTR_FLAG;
857	}
858
859	/* Check the frame received is FD or not*/
860	if (dlc & XCAN_DLCR_EDL_MASK) {
861		for (i = 0; i < cf->len; i += 4) {
862			dw_offset = XCANFD_FRAME_DW_OFFSET(frame_base) +
863					(dwindex * XCANFD_DW_BYTES);
864			data[0] = priv->read_reg(priv, dw_offset);
865			*(__be32 *)(cf->data + i) = cpu_to_be32(data[0]);
866			dwindex++;
867		}
868	} else {
869		for (i = 0; i < cf->len; i += 4) {
870			dw_offset = XCANFD_FRAME_DW_OFFSET(frame_base);
871			data[0] = priv->read_reg(priv, dw_offset + i);
872			*(__be32 *)(cf->data + i) = cpu_to_be32(data[0]);
873		}
874	}
875	stats->rx_bytes += cf->len;
876	stats->rx_packets++;
877	netif_receive_skb(skb);
878
879	return 1;
880}
881
882/**
883 * xcan_current_error_state - Get current error state from HW
884 * @ndev:	Pointer to net_device structure
885 *
886 * Checks the current CAN error state from the HW. Note that this
887 * only checks for ERROR_PASSIVE and ERROR_WARNING.
888 *
889 * Return:
890 * ERROR_PASSIVE or ERROR_WARNING if either is active, ERROR_ACTIVE
891 * otherwise.
892 */
893static enum can_state xcan_current_error_state(struct net_device *ndev)
894{
895	struct xcan_priv *priv = netdev_priv(ndev);
896	u32 status = priv->read_reg(priv, XCAN_SR_OFFSET);
897
898	if ((status & XCAN_SR_ESTAT_MASK) == XCAN_SR_ESTAT_MASK)
899		return CAN_STATE_ERROR_PASSIVE;
900	else if (status & XCAN_SR_ERRWRN_MASK)
901		return CAN_STATE_ERROR_WARNING;
902	else
903		return CAN_STATE_ERROR_ACTIVE;
904}
905
906/**
907 * xcan_set_error_state - Set new CAN error state
908 * @ndev:	Pointer to net_device structure
909 * @new_state:	The new CAN state to be set
910 * @cf:		Error frame to be populated or NULL
911 *
912 * Set new CAN error state for the device, updating statistics and
913 * populating the error frame if given.
914 */
915static void xcan_set_error_state(struct net_device *ndev,
916				 enum can_state new_state,
917				 struct can_frame *cf)
918{
919	struct xcan_priv *priv = netdev_priv(ndev);
920	u32 ecr = priv->read_reg(priv, XCAN_ECR_OFFSET);
921	u32 txerr = ecr & XCAN_ECR_TEC_MASK;
922	u32 rxerr = (ecr & XCAN_ECR_REC_MASK) >> XCAN_ESR_REC_SHIFT;
923	enum can_state tx_state = txerr >= rxerr ? new_state : 0;
924	enum can_state rx_state = txerr <= rxerr ? new_state : 0;
925
926	/* non-ERROR states are handled elsewhere */
927	if (WARN_ON(new_state > CAN_STATE_ERROR_PASSIVE))
928		return;
929
930	can_change_state(ndev, cf, tx_state, rx_state);
931
932	if (cf) {
933		cf->data[6] = txerr;
934		cf->data[7] = rxerr;
935	}
936}
937
938/**
939 * xcan_update_error_state_after_rxtx - Update CAN error state after RX/TX
940 * @ndev:	Pointer to net_device structure
941 *
942 * If the device is in a ERROR-WARNING or ERROR-PASSIVE state, check if
943 * the performed RX/TX has caused it to drop to a lesser state and set
944 * the interface state accordingly.
945 */
946static void xcan_update_error_state_after_rxtx(struct net_device *ndev)
947{
948	struct xcan_priv *priv = netdev_priv(ndev);
949	enum can_state old_state = priv->can.state;
950	enum can_state new_state;
951
952	/* changing error state due to successful frame RX/TX can only
953	 * occur from these states
954	 */
955	if (old_state != CAN_STATE_ERROR_WARNING &&
956	    old_state != CAN_STATE_ERROR_PASSIVE)
957		return;
958
959	new_state = xcan_current_error_state(ndev);
960
961	if (new_state != old_state) {
962		struct sk_buff *skb;
963		struct can_frame *cf;
964
965		skb = alloc_can_err_skb(ndev, &cf);
966
967		xcan_set_error_state(ndev, new_state, skb ? cf : NULL);
968
969		if (skb) {
970			struct net_device_stats *stats = &ndev->stats;
971
972			stats->rx_packets++;
973			stats->rx_bytes += cf->can_dlc;
974			netif_rx(skb);
975		}
976	}
977}
978
979/**
980 * xcan_err_interrupt - error frame Isr
981 * @ndev:	net_device pointer
982 * @isr:	interrupt status register value
983 *
984 * This is the CAN error interrupt and it will
985 * check the the type of error and forward the error
986 * frame to upper layers.
987 */
988static void xcan_err_interrupt(struct net_device *ndev, u32 isr)
989{
990	struct xcan_priv *priv = netdev_priv(ndev);
991	struct net_device_stats *stats = &ndev->stats;
992	struct can_frame cf = { };
993	u32 err_status;
994
995	err_status = priv->read_reg(priv, XCAN_ESR_OFFSET);
996	priv->write_reg(priv, XCAN_ESR_OFFSET, err_status);
997
998	if (isr & XCAN_IXR_BSOFF_MASK) {
999		priv->can.state = CAN_STATE_BUS_OFF;
1000		priv->can.can_stats.bus_off++;
1001		/* Leave device in Config Mode in bus-off state */
1002		priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK);
1003		can_bus_off(ndev);
1004		cf.can_id |= CAN_ERR_BUSOFF;
1005	} else {
1006		enum can_state new_state = xcan_current_error_state(ndev);
1007
1008		if (new_state != priv->can.state)
1009			xcan_set_error_state(ndev, new_state, &cf);
1010	}
1011
1012	/* Check for Arbitration lost interrupt */
1013	if (isr & XCAN_IXR_ARBLST_MASK) {
1014		priv->can.can_stats.arbitration_lost++;
1015		cf.can_id |= CAN_ERR_LOSTARB;
1016		cf.data[0] = CAN_ERR_LOSTARB_UNSPEC;
1017	}
1018
1019	/* Check for RX FIFO Overflow interrupt */
1020	if (isr & XCAN_IXR_RXOFLW_MASK) {
1021		stats->rx_over_errors++;
1022		stats->rx_errors++;
1023		cf.can_id |= CAN_ERR_CRTL;
1024		cf.data[1] |= CAN_ERR_CRTL_RX_OVERFLOW;
1025	}
1026
1027	/* Check for RX Match Not Finished interrupt */
1028	if (isr & XCAN_IXR_RXMNF_MASK) {
1029		stats->rx_dropped++;
1030		stats->rx_errors++;
1031		netdev_err(ndev, "RX match not finished, frame discarded\n");
1032		cf.can_id |= CAN_ERR_CRTL;
1033		cf.data[1] |= CAN_ERR_CRTL_UNSPEC;
1034	}
1035
1036	/* Check for error interrupt */
1037	if (isr & XCAN_IXR_ERROR_MASK) {
1038		bool berr_reporting = false;
1039
1040		if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) {
1041			berr_reporting = true;
1042			cf.can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
1043		}
1044
1045		/* Check for Ack error interrupt */
1046		if (err_status & XCAN_ESR_ACKER_MASK) {
1047			stats->tx_errors++;
1048			if (berr_reporting) {
1049				cf.can_id |= CAN_ERR_ACK;
1050				cf.data[3] = CAN_ERR_PROT_LOC_ACK;
1051			}
1052		}
1053
1054		/* Check for Bit error interrupt */
1055		if (err_status & XCAN_ESR_BERR_MASK) {
1056			stats->tx_errors++;
1057			if (berr_reporting) {
1058				cf.can_id |= CAN_ERR_PROT;
1059				cf.data[2] = CAN_ERR_PROT_BIT;
1060			}
1061		}
1062
1063		/* Check for Stuff error interrupt */
1064		if (err_status & XCAN_ESR_STER_MASK) {
1065			stats->rx_errors++;
1066			if (berr_reporting) {
1067				cf.can_id |= CAN_ERR_PROT;
1068				cf.data[2] = CAN_ERR_PROT_STUFF;
1069			}
1070		}
1071
1072		/* Check for Form error interrupt */
1073		if (err_status & XCAN_ESR_FMER_MASK) {
1074			stats->rx_errors++;
1075			if (berr_reporting) {
1076				cf.can_id |= CAN_ERR_PROT;
1077				cf.data[2] = CAN_ERR_PROT_FORM;
1078			}
1079		}
1080
1081		/* Check for CRC error interrupt */
1082		if (err_status & XCAN_ESR_CRCER_MASK) {
1083			stats->rx_errors++;
1084			if (berr_reporting) {
1085				cf.can_id |= CAN_ERR_PROT;
1086				cf.data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
1087			}
1088		}
1089		priv->can.can_stats.bus_error++;
1090	}
1091
1092	if (cf.can_id) {
1093		struct can_frame *skb_cf;
1094		struct sk_buff *skb = alloc_can_err_skb(ndev, &skb_cf);
1095
1096		if (skb) {
1097			skb_cf->can_id |= cf.can_id;
1098			memcpy(skb_cf->data, cf.data, CAN_ERR_DLC);
1099			stats->rx_packets++;
1100			stats->rx_bytes += CAN_ERR_DLC;
1101			netif_rx(skb);
1102		}
1103	}
1104
1105	netdev_dbg(ndev, "%s: error status register:0x%x\n",
1106		   __func__, priv->read_reg(priv, XCAN_ESR_OFFSET));
1107}
1108
1109/**
1110 * xcan_state_interrupt - It will check the state of the CAN device
1111 * @ndev:	net_device pointer
1112 * @isr:	interrupt status register value
1113 *
1114 * This will checks the state of the CAN device
1115 * and puts the device into appropriate state.
1116 */
1117static void xcan_state_interrupt(struct net_device *ndev, u32 isr)
1118{
1119	struct xcan_priv *priv = netdev_priv(ndev);
1120
1121	/* Check for Sleep interrupt if set put CAN device in sleep state */
1122	if (isr & XCAN_IXR_SLP_MASK)
1123		priv->can.state = CAN_STATE_SLEEPING;
1124
1125	/* Check for Wake up interrupt if set put CAN device in Active state */
1126	if (isr & XCAN_IXR_WKUP_MASK)
1127		priv->can.state = CAN_STATE_ERROR_ACTIVE;
1128}
1129
1130/**
1131 * xcan_rx_fifo_get_next_frame - Get register offset of next RX frame
1132 * @priv:	Driver private data structure
1133 *
1134 * Return: Register offset of the next frame in RX FIFO.
1135 */
1136static int xcan_rx_fifo_get_next_frame(struct xcan_priv *priv)
1137{
1138	int offset;
1139
1140	if (priv->devtype.flags & XCAN_FLAG_RX_FIFO_MULTI) {
1141		u32 fsr, mask;
1142
1143		/* clear RXOK before the is-empty check so that any newly
1144		 * received frame will reassert it without a race
1145		 */
1146		priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_RXOK_MASK);
1147
1148		fsr = priv->read_reg(priv, XCAN_FSR_OFFSET);
1149
1150		/* check if RX FIFO is empty */
1151		if (priv->devtype.flags & XCAN_FLAG_CANFD_2)
1152			mask = XCAN_2_FSR_FL_MASK;
1153		else
1154			mask = XCAN_FSR_FL_MASK;
1155
1156		if (!(fsr & mask))
1157			return -ENOENT;
1158
1159		if (priv->devtype.flags & XCAN_FLAG_CANFD_2)
1160			offset =
1161			  XCAN_RXMSG_2_FRAME_OFFSET(fsr & XCAN_2_FSR_RI_MASK);
1162		else
1163			offset =
1164			  XCAN_RXMSG_FRAME_OFFSET(fsr & XCAN_FSR_RI_MASK);
1165
1166	} else {
1167		/* check if RX FIFO is empty */
1168		if (!(priv->read_reg(priv, XCAN_ISR_OFFSET) &
1169		      XCAN_IXR_RXNEMP_MASK))
1170			return -ENOENT;
1171
1172		/* frames are read from a static offset */
1173		offset = XCAN_RXFIFO_OFFSET;
1174	}
1175
1176	return offset;
1177}
1178
1179/**
1180 * xcan_rx_poll - Poll routine for rx packets (NAPI)
1181 * @napi:	napi structure pointer
1182 * @quota:	Max number of rx packets to be processed.
1183 *
1184 * This is the poll routine for rx part.
1185 * It will process the packets maximux quota value.
1186 *
1187 * Return: number of packets received
1188 */
1189static int xcan_rx_poll(struct napi_struct *napi, int quota)
1190{
1191	struct net_device *ndev = napi->dev;
1192	struct xcan_priv *priv = netdev_priv(ndev);
1193	u32 ier;
1194	int work_done = 0;
1195	int frame_offset;
1196
1197	while ((frame_offset = xcan_rx_fifo_get_next_frame(priv)) >= 0 &&
1198	       (work_done < quota)) {
1199		if (xcan_rx_int_mask(priv) & XCAN_IXR_RXOK_MASK)
1200			work_done += xcanfd_rx(ndev, frame_offset);
1201		else
1202			work_done += xcan_rx(ndev, frame_offset);
1203
1204		if (priv->devtype.flags & XCAN_FLAG_RX_FIFO_MULTI)
1205			/* increment read index */
1206			priv->write_reg(priv, XCAN_FSR_OFFSET,
1207					XCAN_FSR_IRI_MASK);
1208		else
1209			/* clear rx-not-empty (will actually clear only if
1210			 * empty)
1211			 */
1212			priv->write_reg(priv, XCAN_ICR_OFFSET,
1213					XCAN_IXR_RXNEMP_MASK);
1214	}
1215
1216	if (work_done) {
1217		can_led_event(ndev, CAN_LED_EVENT_RX);
1218		xcan_update_error_state_after_rxtx(ndev);
1219	}
1220
1221	if (work_done < quota) {
1222		napi_complete_done(napi, work_done);
1223		ier = priv->read_reg(priv, XCAN_IER_OFFSET);
1224		ier |= xcan_rx_int_mask(priv);
1225		priv->write_reg(priv, XCAN_IER_OFFSET, ier);
1226	}
1227	return work_done;
1228}
1229
1230/**
1231 * xcan_tx_interrupt - Tx Done Isr
1232 * @ndev:	net_device pointer
1233 * @isr:	Interrupt status register value
1234 */
1235static void xcan_tx_interrupt(struct net_device *ndev, u32 isr)
1236{
1237	struct xcan_priv *priv = netdev_priv(ndev);
1238	struct net_device_stats *stats = &ndev->stats;
1239	unsigned int frames_in_fifo;
1240	int frames_sent = 1; /* TXOK => at least 1 frame was sent */
1241	unsigned long flags;
1242	int retries = 0;
1243
1244	/* Synchronize with xmit as we need to know the exact number
1245	 * of frames in the FIFO to stay in sync due to the TXFEMP
1246	 * handling.
1247	 * This also prevents a race between netif_wake_queue() and
1248	 * netif_stop_queue().
1249	 */
1250	spin_lock_irqsave(&priv->tx_lock, flags);
1251
1252	frames_in_fifo = priv->tx_head - priv->tx_tail;
1253
1254	if (WARN_ON_ONCE(frames_in_fifo == 0)) {
1255		/* clear TXOK anyway to avoid getting back here */
1256		priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_TXOK_MASK);
1257		spin_unlock_irqrestore(&priv->tx_lock, flags);
1258		return;
1259	}
1260
1261	/* Check if 2 frames were sent (TXOK only means that at least 1
1262	 * frame was sent).
1263	 */
1264	if (frames_in_fifo > 1) {
1265		WARN_ON(frames_in_fifo > priv->tx_max);
1266
1267		/* Synchronize TXOK and isr so that after the loop:
1268		 * (1) isr variable is up-to-date at least up to TXOK clear
1269		 *     time. This avoids us clearing a TXOK of a second frame
1270		 *     but not noticing that the FIFO is now empty and thus
1271		 *     marking only a single frame as sent.
1272		 * (2) No TXOK is left. Having one could mean leaving a
1273		 *     stray TXOK as we might process the associated frame
1274		 *     via TXFEMP handling as we read TXFEMP *after* TXOK
1275		 *     clear to satisfy (1).
1276		 */
1277		while ((isr & XCAN_IXR_TXOK_MASK) &&
1278		       !WARN_ON(++retries == 100)) {
1279			priv->write_reg(priv, XCAN_ICR_OFFSET,
1280					XCAN_IXR_TXOK_MASK);
1281			isr = priv->read_reg(priv, XCAN_ISR_OFFSET);
1282		}
1283
1284		if (isr & XCAN_IXR_TXFEMP_MASK) {
1285			/* nothing in FIFO anymore */
1286			frames_sent = frames_in_fifo;
1287		}
1288	} else {
1289		/* single frame in fifo, just clear TXOK */
1290		priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_TXOK_MASK);
1291	}
1292
1293	while (frames_sent--) {
1294		stats->tx_bytes += can_get_echo_skb(ndev, priv->tx_tail %
1295						    priv->tx_max);
1296		priv->tx_tail++;
1297		stats->tx_packets++;
1298	}
1299
1300	netif_wake_queue(ndev);
1301
1302	spin_unlock_irqrestore(&priv->tx_lock, flags);
1303
1304	can_led_event(ndev, CAN_LED_EVENT_TX);
1305	xcan_update_error_state_after_rxtx(ndev);
1306}
1307
1308/**
1309 * xcan_interrupt - CAN Isr
1310 * @irq:	irq number
1311 * @dev_id:	device id pointer
1312 *
1313 * This is the xilinx CAN Isr. It checks for the type of interrupt
1314 * and invokes the corresponding ISR.
1315 *
1316 * Return:
1317 * IRQ_NONE - If CAN device is in sleep mode, IRQ_HANDLED otherwise
1318 */
1319static irqreturn_t xcan_interrupt(int irq, void *dev_id)
1320{
1321	struct net_device *ndev = (struct net_device *)dev_id;
1322	struct xcan_priv *priv = netdev_priv(ndev);
1323	u32 isr, ier;
1324	u32 isr_errors;
1325	u32 rx_int_mask = xcan_rx_int_mask(priv);
1326
1327	/* Get the interrupt status from Xilinx CAN */
1328	isr = priv->read_reg(priv, XCAN_ISR_OFFSET);
1329	if (!isr)
1330		return IRQ_NONE;
1331
1332	/* Check for the type of interrupt and Processing it */
1333	if (isr & (XCAN_IXR_SLP_MASK | XCAN_IXR_WKUP_MASK)) {
1334		priv->write_reg(priv, XCAN_ICR_OFFSET, (XCAN_IXR_SLP_MASK |
1335				XCAN_IXR_WKUP_MASK));
1336		xcan_state_interrupt(ndev, isr);
1337	}
1338
1339	/* Check for Tx interrupt and Processing it */
1340	if (isr & XCAN_IXR_TXOK_MASK)
1341		xcan_tx_interrupt(ndev, isr);
1342
1343	/* Check for the type of error interrupt and Processing it */
1344	isr_errors = isr & (XCAN_IXR_ERROR_MASK | XCAN_IXR_RXOFLW_MASK |
1345			    XCAN_IXR_BSOFF_MASK | XCAN_IXR_ARBLST_MASK |
1346			    XCAN_IXR_RXMNF_MASK);
1347	if (isr_errors) {
1348		priv->write_reg(priv, XCAN_ICR_OFFSET, isr_errors);
1349		xcan_err_interrupt(ndev, isr);
1350	}
1351
1352	/* Check for the type of receive interrupt and Processing it */
1353	if (isr & rx_int_mask) {
1354		ier = priv->read_reg(priv, XCAN_IER_OFFSET);
1355		ier &= ~rx_int_mask;
1356		priv->write_reg(priv, XCAN_IER_OFFSET, ier);
1357		napi_schedule(&priv->napi);
1358	}
1359	return IRQ_HANDLED;
1360}
1361
1362/**
1363 * xcan_chip_stop - Driver stop routine
1364 * @ndev:	Pointer to net_device structure
1365 *
1366 * This is the drivers stop routine. It will disable the
1367 * interrupts and put the device into configuration mode.
1368 */
1369static void xcan_chip_stop(struct net_device *ndev)
1370{
1371	struct xcan_priv *priv = netdev_priv(ndev);
1372	int ret;
1373
1374	/* Disable interrupts and leave the can in configuration mode */
1375	ret = set_reset_mode(ndev);
1376	if (ret < 0)
1377		netdev_dbg(ndev, "set_reset_mode() Failed\n");
1378
1379	priv->can.state = CAN_STATE_STOPPED;
1380}
1381
1382/**
1383 * xcan_open - Driver open routine
1384 * @ndev:	Pointer to net_device structure
1385 *
1386 * This is the driver open routine.
1387 * Return: 0 on success and failure value on error
1388 */
1389static int xcan_open(struct net_device *ndev)
1390{
1391	struct xcan_priv *priv = netdev_priv(ndev);
1392	int ret;
1393
1394	ret = pm_runtime_get_sync(priv->dev);
1395	if (ret < 0) {
1396		netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
1397			   __func__, ret);
1398		goto err;
1399	}
1400
1401	ret = request_irq(ndev->irq, xcan_interrupt, priv->irq_flags,
1402			  ndev->name, ndev);
1403	if (ret < 0) {
1404		netdev_err(ndev, "irq allocation for CAN failed\n");
1405		goto err;
1406	}
1407
1408	/* Set chip into reset mode */
1409	ret = set_reset_mode(ndev);
1410	if (ret < 0) {
1411		netdev_err(ndev, "mode resetting failed!\n");
1412		goto err_irq;
1413	}
1414
1415	/* Common open */
1416	ret = open_candev(ndev);
1417	if (ret)
1418		goto err_irq;
1419
1420	ret = xcan_chip_start(ndev);
1421	if (ret < 0) {
1422		netdev_err(ndev, "xcan_chip_start failed!\n");
1423		goto err_candev;
1424	}
1425
1426	can_led_event(ndev, CAN_LED_EVENT_OPEN);
1427	napi_enable(&priv->napi);
1428	netif_start_queue(ndev);
1429
1430	return 0;
1431
1432err_candev:
1433	close_candev(ndev);
1434err_irq:
1435	free_irq(ndev->irq, ndev);
1436err:
1437	pm_runtime_put(priv->dev);
1438
1439	return ret;
1440}
1441
1442/**
1443 * xcan_close - Driver close routine
1444 * @ndev:	Pointer to net_device structure
1445 *
1446 * Return: 0 always
1447 */
1448static int xcan_close(struct net_device *ndev)
1449{
1450	struct xcan_priv *priv = netdev_priv(ndev);
1451
1452	netif_stop_queue(ndev);
1453	napi_disable(&priv->napi);
1454	xcan_chip_stop(ndev);
1455	free_irq(ndev->irq, ndev);
1456	close_candev(ndev);
1457
1458	can_led_event(ndev, CAN_LED_EVENT_STOP);
1459	pm_runtime_put(priv->dev);
1460
1461	return 0;
1462}
1463
1464/**
1465 * xcan_get_berr_counter - error counter routine
1466 * @ndev:	Pointer to net_device structure
1467 * @bec:	Pointer to can_berr_counter structure
1468 *
1469 * This is the driver error counter routine.
1470 * Return: 0 on success and failure value on error
1471 */
1472static int xcan_get_berr_counter(const struct net_device *ndev,
1473				 struct can_berr_counter *bec)
1474{
1475	struct xcan_priv *priv = netdev_priv(ndev);
1476	int ret;
1477
1478	ret = pm_runtime_get_sync(priv->dev);
1479	if (ret < 0) {
1480		netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
1481			   __func__, ret);
1482		pm_runtime_put(priv->dev);
1483		return ret;
1484	}
1485
1486	bec->txerr = priv->read_reg(priv, XCAN_ECR_OFFSET) & XCAN_ECR_TEC_MASK;
1487	bec->rxerr = ((priv->read_reg(priv, XCAN_ECR_OFFSET) &
1488			XCAN_ECR_REC_MASK) >> XCAN_ESR_REC_SHIFT);
1489
1490	pm_runtime_put(priv->dev);
1491
1492	return 0;
1493}
1494
1495static const struct net_device_ops xcan_netdev_ops = {
1496	.ndo_open	= xcan_open,
1497	.ndo_stop	= xcan_close,
1498	.ndo_start_xmit	= xcan_start_xmit,
1499	.ndo_change_mtu	= can_change_mtu,
1500};
1501
1502/**
1503 * xcan_suspend - Suspend method for the driver
1504 * @dev:	Address of the device structure
1505 *
1506 * Put the driver into low power mode.
1507 * Return: 0 on success and failure value on error
1508 */
1509static int __maybe_unused xcan_suspend(struct device *dev)
1510{
1511	struct net_device *ndev = dev_get_drvdata(dev);
1512
1513	if (netif_running(ndev)) {
1514		netif_stop_queue(ndev);
1515		netif_device_detach(ndev);
1516		xcan_chip_stop(ndev);
1517	}
1518
1519	return pm_runtime_force_suspend(dev);
1520}
1521
1522/**
1523 * xcan_resume - Resume from suspend
1524 * @dev:	Address of the device structure
1525 *
1526 * Resume operation after suspend.
1527 * Return: 0 on success and failure value on error
1528 */
1529static int __maybe_unused xcan_resume(struct device *dev)
1530{
1531	struct net_device *ndev = dev_get_drvdata(dev);
1532	int ret;
1533
1534	ret = pm_runtime_force_resume(dev);
1535	if (ret) {
1536		dev_err(dev, "pm_runtime_force_resume failed on resume\n");
1537		return ret;
1538	}
1539
1540	if (netif_running(ndev)) {
1541		ret = xcan_chip_start(ndev);
1542		if (ret) {
1543			dev_err(dev, "xcan_chip_start failed on resume\n");
1544			return ret;
1545		}
1546
1547		netif_device_attach(ndev);
1548		netif_start_queue(ndev);
1549	}
1550
1551	return 0;
1552}
1553
1554/**
1555 * xcan_runtime_suspend - Runtime suspend method for the driver
1556 * @dev:	Address of the device structure
1557 *
1558 * Put the driver into low power mode.
1559 * Return: 0 always
1560 */
1561static int __maybe_unused xcan_runtime_suspend(struct device *dev)
1562{
1563	struct net_device *ndev = dev_get_drvdata(dev);
1564	struct xcan_priv *priv = netdev_priv(ndev);
1565
1566	clk_disable_unprepare(priv->bus_clk);
1567	clk_disable_unprepare(priv->can_clk);
1568
1569	return 0;
1570}
1571
1572/**
1573 * xcan_runtime_resume - Runtime resume from suspend
1574 * @dev:	Address of the device structure
1575 *
1576 * Resume operation after suspend.
1577 * Return: 0 on success and failure value on error
1578 */
1579static int __maybe_unused xcan_runtime_resume(struct device *dev)
1580{
1581	struct net_device *ndev = dev_get_drvdata(dev);
1582	struct xcan_priv *priv = netdev_priv(ndev);
1583	int ret;
1584
1585	ret = clk_prepare_enable(priv->bus_clk);
1586	if (ret) {
1587		dev_err(dev, "Cannot enable clock.\n");
1588		return ret;
1589	}
1590	ret = clk_prepare_enable(priv->can_clk);
1591	if (ret) {
1592		dev_err(dev, "Cannot enable clock.\n");
1593		clk_disable_unprepare(priv->bus_clk);
1594		return ret;
1595	}
1596
1597	return 0;
1598}
1599
1600static const struct dev_pm_ops xcan_dev_pm_ops = {
1601	SET_SYSTEM_SLEEP_PM_OPS(xcan_suspend, xcan_resume)
1602	SET_RUNTIME_PM_OPS(xcan_runtime_suspend, xcan_runtime_resume, NULL)
1603};
1604
1605static const struct xcan_devtype_data xcan_zynq_data = {
1606	.cantype = XZYNQ_CANPS,
1607	.flags = XCAN_FLAG_TXFEMP,
1608	.bittiming_const = &xcan_bittiming_const,
1609	.btr_ts2_shift = XCAN_BTR_TS2_SHIFT,
1610	.btr_sjw_shift = XCAN_BTR_SJW_SHIFT,
1611	.bus_clk_name = "pclk",
1612};
1613
1614static const struct xcan_devtype_data xcan_axi_data = {
1615	.cantype = XAXI_CAN,
1616	.bittiming_const = &xcan_bittiming_const,
1617	.btr_ts2_shift = XCAN_BTR_TS2_SHIFT,
1618	.btr_sjw_shift = XCAN_BTR_SJW_SHIFT,
1619	.bus_clk_name = "s_axi_aclk",
1620};
1621
1622static const struct xcan_devtype_data xcan_canfd_data = {
1623	.cantype = XAXI_CANFD,
1624	.flags = XCAN_FLAG_EXT_FILTERS |
1625		 XCAN_FLAG_RXMNF |
1626		 XCAN_FLAG_TX_MAILBOXES |
1627		 XCAN_FLAG_RX_FIFO_MULTI,
1628	.bittiming_const = &xcan_bittiming_const_canfd,
1629	.btr_ts2_shift = XCAN_BTR_TS2_SHIFT_CANFD,
1630	.btr_sjw_shift = XCAN_BTR_SJW_SHIFT_CANFD,
1631	.bus_clk_name = "s_axi_aclk",
1632};
1633
1634static const struct xcan_devtype_data xcan_canfd2_data = {
1635	.cantype = XAXI_CANFD_2_0,
1636	.flags = XCAN_FLAG_EXT_FILTERS |
1637		 XCAN_FLAG_RXMNF |
1638		 XCAN_FLAG_TX_MAILBOXES |
1639		 XCAN_FLAG_CANFD_2 |
1640		 XCAN_FLAG_RX_FIFO_MULTI,
1641	.bittiming_const = &xcan_bittiming_const_canfd2,
1642	.btr_ts2_shift = XCAN_BTR_TS2_SHIFT_CANFD,
1643	.btr_sjw_shift = XCAN_BTR_SJW_SHIFT_CANFD,
1644	.bus_clk_name = "s_axi_aclk",
1645};
1646
1647/* Match table for OF platform binding */
1648static const struct of_device_id xcan_of_match[] = {
1649	{ .compatible = "xlnx,zynq-can-1.0", .data = &xcan_zynq_data },
1650	{ .compatible = "xlnx,axi-can-1.00.a", .data = &xcan_axi_data },
1651	{ .compatible = "xlnx,canfd-1.0", .data = &xcan_canfd_data },
1652	{ .compatible = "xlnx,canfd-2.0", .data = &xcan_canfd2_data },
1653	{ /* end of list */ },
1654};
1655MODULE_DEVICE_TABLE(of, xcan_of_match);
1656
1657/**
1658 * xcan_probe - Platform registration call
1659 * @pdev:	Handle to the platform device structure
1660 *
1661 * This function does all the memory allocation and registration for the CAN
1662 * device.
1663 *
1664 * Return: 0 on success and failure value on error
1665 */
1666static int xcan_probe(struct platform_device *pdev)
1667{
1668	struct net_device *ndev;
1669	struct xcan_priv *priv;
1670	const struct of_device_id *of_id;
1671	const struct xcan_devtype_data *devtype = &xcan_axi_data;
1672	void __iomem *addr;
1673	int ret;
1674	int rx_max, tx_max;
1675	u32 hw_tx_max = 0, hw_rx_max = 0;
1676	const char *hw_tx_max_property;
1677
1678	/* Get the virtual base address for the device */
1679	addr = devm_platform_ioremap_resource(pdev, 0);
1680	if (IS_ERR(addr)) {
1681		ret = PTR_ERR(addr);
1682		goto err;
1683	}
1684
1685	of_id = of_match_device(xcan_of_match, &pdev->dev);
1686	if (of_id && of_id->data)
1687		devtype = of_id->data;
1688
1689	hw_tx_max_property = devtype->flags & XCAN_FLAG_TX_MAILBOXES ?
1690			     "tx-mailbox-count" : "tx-fifo-depth";
1691
1692	ret = of_property_read_u32(pdev->dev.of_node, hw_tx_max_property,
1693				   &hw_tx_max);
1694	if (ret < 0) {
1695		dev_err(&pdev->dev, "missing %s property\n",
1696			hw_tx_max_property);
1697		goto err;
1698	}
1699
1700	ret = of_property_read_u32(pdev->dev.of_node, "rx-fifo-depth",
1701				   &hw_rx_max);
1702	if (ret < 0) {
1703		dev_err(&pdev->dev,
1704			"missing rx-fifo-depth property (mailbox mode is not supported)\n");
1705		goto err;
1706	}
1707
1708	/* With TX FIFO:
1709	 *
1710	 * There is no way to directly figure out how many frames have been
1711	 * sent when the TXOK interrupt is processed. If TXFEMP
1712	 * is supported, we can have 2 frames in the FIFO and use TXFEMP
1713	 * to determine if 1 or 2 frames have been sent.
1714	 * Theoretically we should be able to use TXFWMEMP to determine up
1715	 * to 3 frames, but it seems that after putting a second frame in the
1716	 * FIFO, with watermark at 2 frames, it can happen that TXFWMEMP (less
1717	 * than 2 frames in FIFO) is set anyway with no TXOK (a frame was
1718	 * sent), which is not a sensible state - possibly TXFWMEMP is not
1719	 * completely synchronized with the rest of the bits?
1720	 *
1721	 * With TX mailboxes:
1722	 *
1723	 * HW sends frames in CAN ID priority order. To preserve FIFO ordering
1724	 * we submit frames one at a time.
1725	 */
1726	if (!(devtype->flags & XCAN_FLAG_TX_MAILBOXES) &&
1727	    (devtype->flags & XCAN_FLAG_TXFEMP))
1728		tx_max = min(hw_tx_max, 2U);
1729	else
1730		tx_max = 1;
1731
1732	rx_max = hw_rx_max;
1733
1734	/* Create a CAN device instance */
1735	ndev = alloc_candev(sizeof(struct xcan_priv), tx_max);
1736	if (!ndev)
1737		return -ENOMEM;
1738
1739	priv = netdev_priv(ndev);
1740	priv->dev = &pdev->dev;
1741	priv->can.bittiming_const = devtype->bittiming_const;
1742	priv->can.do_set_mode = xcan_do_set_mode;
1743	priv->can.do_get_berr_counter = xcan_get_berr_counter;
1744	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
1745					CAN_CTRLMODE_BERR_REPORTING;
1746
1747	if (devtype->cantype == XAXI_CANFD)
1748		priv->can.data_bittiming_const =
1749			&xcan_data_bittiming_const_canfd;
1750
1751	if (devtype->cantype == XAXI_CANFD_2_0)
1752		priv->can.data_bittiming_const =
1753			&xcan_data_bittiming_const_canfd2;
1754
1755	if (devtype->cantype == XAXI_CANFD ||
1756	    devtype->cantype == XAXI_CANFD_2_0)
1757		priv->can.ctrlmode_supported |= CAN_CTRLMODE_FD;
1758
1759	priv->reg_base = addr;
1760	priv->tx_max = tx_max;
1761	priv->devtype = *devtype;
1762	spin_lock_init(&priv->tx_lock);
1763
1764	/* Get IRQ for the device */
1765	ret = platform_get_irq(pdev, 0);
1766	if (ret < 0)
1767		goto err_free;
1768
1769	ndev->irq = ret;
1770
1771	ndev->flags |= IFF_ECHO;	/* We support local echo */
1772
1773	platform_set_drvdata(pdev, ndev);
1774	SET_NETDEV_DEV(ndev, &pdev->dev);
1775	ndev->netdev_ops = &xcan_netdev_ops;
1776
1777	/* Getting the CAN can_clk info */
1778	priv->can_clk = devm_clk_get(&pdev->dev, "can_clk");
1779	if (IS_ERR(priv->can_clk)) {
1780		if (PTR_ERR(priv->can_clk) != -EPROBE_DEFER)
1781			dev_err(&pdev->dev, "Device clock not found.\n");
1782		ret = PTR_ERR(priv->can_clk);
1783		goto err_free;
1784	}
1785
1786	priv->bus_clk = devm_clk_get(&pdev->dev, devtype->bus_clk_name);
1787	if (IS_ERR(priv->bus_clk)) {
1788		if (PTR_ERR(priv->bus_clk) != -EPROBE_DEFER)
1789			dev_err(&pdev->dev, "bus clock not found\n");
1790		ret = PTR_ERR(priv->bus_clk);
1791		goto err_free;
1792	}
1793
1794	priv->write_reg = xcan_write_reg_le;
1795	priv->read_reg = xcan_read_reg_le;
1796
1797	pm_runtime_enable(&pdev->dev);
1798	ret = pm_runtime_get_sync(&pdev->dev);
1799	if (ret < 0) {
1800		netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
1801			   __func__, ret);
1802		goto err_disableclks;
1803	}
1804
1805	if (priv->read_reg(priv, XCAN_SR_OFFSET) != XCAN_SR_CONFIG_MASK) {
1806		priv->write_reg = xcan_write_reg_be;
1807		priv->read_reg = xcan_read_reg_be;
1808	}
1809
1810	priv->can.clock.freq = clk_get_rate(priv->can_clk);
1811
1812	netif_napi_add(ndev, &priv->napi, xcan_rx_poll, rx_max);
1813
1814	ret = register_candev(ndev);
1815	if (ret) {
1816		dev_err(&pdev->dev, "fail to register failed (err=%d)\n", ret);
1817		goto err_disableclks;
1818	}
1819
1820	devm_can_led_init(ndev);
1821
1822	pm_runtime_put(&pdev->dev);
1823
1824	if (priv->devtype.flags & XCAN_FLAG_CANFD_2) {
1825		priv->write_reg(priv, XCAN_AFR_2_ID_OFFSET, 0x00000000);
1826		priv->write_reg(priv, XCAN_AFR_2_MASK_OFFSET, 0x00000000);
1827	}
1828
1829	netdev_dbg(ndev, "reg_base=0x%p irq=%d clock=%d, tx buffers: actual %d, using %d\n",
1830		   priv->reg_base, ndev->irq, priv->can.clock.freq,
1831		   hw_tx_max, priv->tx_max);
1832
1833	return 0;
1834
1835err_disableclks:
1836	pm_runtime_put(priv->dev);
1837	pm_runtime_disable(&pdev->dev);
1838err_free:
1839	free_candev(ndev);
1840err:
1841	return ret;
1842}
1843
1844/**
1845 * xcan_remove - Unregister the device after releasing the resources
1846 * @pdev:	Handle to the platform device structure
1847 *
1848 * This function frees all the resources allocated to the device.
1849 * Return: 0 always
1850 */
1851static int xcan_remove(struct platform_device *pdev)
1852{
1853	struct net_device *ndev = platform_get_drvdata(pdev);
1854	struct xcan_priv *priv = netdev_priv(ndev);
1855
1856	unregister_candev(ndev);
1857	pm_runtime_disable(&pdev->dev);
1858	netif_napi_del(&priv->napi);
1859	free_candev(ndev);
1860
1861	return 0;
1862}
1863
1864static struct platform_driver xcan_driver = {
1865	.probe = xcan_probe,
1866	.remove	= xcan_remove,
1867	.driver	= {
1868		.name = DRIVER_NAME,
1869		.pm = &xcan_dev_pm_ops,
1870		.of_match_table	= xcan_of_match,
1871	},
1872};
1873
1874module_platform_driver(xcan_driver);
1875
1876MODULE_LICENSE("GPL");
1877MODULE_AUTHOR("Xilinx Inc");
1878MODULE_DESCRIPTION("Xilinx CAN interface");
1879