Linux Audio

Check our new training course

Loading...
  1/* SPDX-License-Identifier: GPL-2.0 */
  2
  3/* Driver for ETAS GmbH ES58X USB CAN(-FD) Bus Interfaces.
  4 *
  5 * File es58x_core.h: All common definitions and declarations.
  6 *
  7 * Copyright (c) 2019 Robert Bosch Engineering and Business Solutions. All rights reserved.
  8 * Copyright (c) 2020 ETAS K.K.. All rights reserved.
  9 * Copyright (c) 2020-2022 Vincent Mailhol <mailhol.vincent@wanadoo.fr>
 10 */
 11
 12#ifndef __ES58X_COMMON_H__
 13#define __ES58X_COMMON_H__
 14
 15#include <linux/can.h>
 16#include <linux/can/dev.h>
 17#include <linux/netdevice.h>
 18#include <linux/types.h>
 19#include <linux/usb.h>
 20#include <net/devlink.h>
 21
 22#include "es581_4.h"
 23#include "es58x_fd.h"
 24
 25/* Driver constants */
 26#define ES58X_RX_URBS_MAX 5	/* Empirical value */
 27#define ES58X_TX_URBS_MAX 6	/* Empirical value */
 28
 29#define ES58X_MAX(param)				\
 30	(ES581_4_##param > ES58X_FD_##param ?		\
 31		ES581_4_##param : ES58X_FD_##param)
 32#define ES58X_TX_BULK_MAX ES58X_MAX(TX_BULK_MAX)
 33#define ES58X_RX_BULK_MAX ES58X_MAX(RX_BULK_MAX)
 34#define ES58X_ECHO_BULK_MAX ES58X_MAX(ECHO_BULK_MAX)
 35#define ES58X_NUM_CAN_CH_MAX ES58X_MAX(NUM_CAN_CH)
 36
 37/* Use this when channel index is irrelevant (e.g. device
 38 * timestamp).
 39 */
 40#define ES58X_CHANNEL_IDX_NA 0xFF
 41#define ES58X_EMPTY_MSG NULL
 42
 43/* Threshold on consecutive CAN_STATE_ERROR_PASSIVE. If we receive
 44 * ES58X_CONSECUTIVE_ERR_PASSIVE_MAX times the event
 45 * ES58X_ERR_CRTL_PASSIVE in a row without any successful RX or TX,
 46 * we force the device to switch to CAN_STATE_BUS_OFF state.
 47 */
 48#define ES58X_CONSECUTIVE_ERR_PASSIVE_MAX 254
 49
 50/* A magic number sent by the ES581.4 to inform it is alive. */
 51#define ES58X_HEARTBEAT 0x11
 52
 53/**
 54 * enum es58x_driver_info - Quirks of the device.
 55 * @ES58X_DUAL_CHANNEL: Device has two CAN channels. If this flag is
 56 *	not set, it is implied that the device has only one CAN
 57 *	channel.
 58 * @ES58X_FD_FAMILY: Device is CAN-FD capable. If this flag is not
 59 *	set, the device only supports classical CAN.
 60 */
 61enum es58x_driver_info {
 62	ES58X_DUAL_CHANNEL = BIT(0),
 63	ES58X_FD_FAMILY = BIT(1)
 64};
 65
 66enum es58x_echo {
 67	ES58X_ECHO_OFF = 0,
 68	ES58X_ECHO_ON = 1
 69};
 70
 71/**
 72 * enum es58x_physical_layer - Type of the physical layer.
 73 * @ES58X_PHYSICAL_LAYER_HIGH_SPEED: High-speed CAN (c.f. ISO
 74 *	11898-2).
 75 *
 76 * Some products of the ETAS portfolio also support low-speed CAN
 77 * (c.f. ISO 11898-3). However, all the devices in scope of this
 78 * driver do not support the option, thus, the enum has only one
 79 * member.
 80 */
 81enum es58x_physical_layer {
 82	ES58X_PHYSICAL_LAYER_HIGH_SPEED = 1
 83};
 84
 85enum es58x_samples_per_bit {
 86	ES58X_SAMPLES_PER_BIT_ONE = 1,
 87	ES58X_SAMPLES_PER_BIT_THREE = 2
 88};
 89
 90/**
 91 * enum es58x_sync_edge - Synchronization method.
 92 * @ES58X_SYNC_EDGE_SINGLE: ISO CAN specification defines the use of a
 93 *	single edge synchronization.  The synchronization should be
 94 *	done on recessive to dominant level change.
 95 *
 96 * For information, ES582.1 and ES584.1 also support a double
 97 * synchronization, requiring both recessive to dominant then dominant
 98 * to recessive level change. However, this is not supported in
 99 * SocketCAN framework, thus, the enum has only one member.
100 */
101enum es58x_sync_edge {
102	ES58X_SYNC_EDGE_SINGLE = 1
103};
104
105/**
106 * enum es58x_flag - CAN flags for RX/TX messages.
107 * @ES58X_FLAG_EFF: Extended Frame Format (EFF).
108 * @ES58X_FLAG_RTR: Remote Transmission Request (RTR).
109 * @ES58X_FLAG_FD_BRS: Bit rate switch (BRS): second bitrate for
110 *	payload data.
111 * @ES58X_FLAG_FD_ESI: Error State Indicator (ESI): tell if the
112 *	transmitting node is in error passive mode.
113 * @ES58X_FLAG_FD_DATA: CAN FD frame.
114 */
115enum es58x_flag {
116	ES58X_FLAG_EFF = BIT(0),
117	ES58X_FLAG_RTR = BIT(1),
118	ES58X_FLAG_FD_BRS = BIT(3),
119	ES58X_FLAG_FD_ESI = BIT(5),
120	ES58X_FLAG_FD_DATA = BIT(6)
121};
122
123/**
124 * enum es58x_err - CAN error detection.
125 * @ES58X_ERR_OK: No errors.
126 * @ES58X_ERR_PROT_STUFF: Bit stuffing error: more than 5 consecutive
127 *	equal bits.
128 * @ES58X_ERR_PROT_FORM: Frame format error.
129 * @ES58X_ERR_ACK: Received no ACK on transmission.
130 * @ES58X_ERR_PROT_BIT: Single bit error.
131 * @ES58X_ERR_PROT_CRC: Incorrect 15, 17 or 21 bits CRC.
132 * @ES58X_ERR_PROT_BIT1: Unable to send recessive bit: tried to send
133 *	recessive bit 1 but monitored dominant bit 0.
134 * @ES58X_ERR_PROT_BIT0: Unable to send dominant bit: tried to send
135 *	dominant bit 0 but monitored recessive bit 1.
136 * @ES58X_ERR_PROT_OVERLOAD: Bus overload.
137 * @ES58X_ERR_PROT_UNSPEC: Unspecified.
138 *
139 * Please refer to ISO 11898-1:2015, section 10.11 "Error detection"
140 * and section 10.13 "Overload signaling" for additional details.
141 */
142enum es58x_err {
143	ES58X_ERR_OK = 0,
144	ES58X_ERR_PROT_STUFF = BIT(0),
145	ES58X_ERR_PROT_FORM = BIT(1),
146	ES58X_ERR_ACK = BIT(2),
147	ES58X_ERR_PROT_BIT = BIT(3),
148	ES58X_ERR_PROT_CRC = BIT(4),
149	ES58X_ERR_PROT_BIT1 = BIT(5),
150	ES58X_ERR_PROT_BIT0 = BIT(6),
151	ES58X_ERR_PROT_OVERLOAD = BIT(7),
152	ES58X_ERR_PROT_UNSPEC = BIT(31)
153};
154
155/**
156 * enum es58x_event - CAN error codes returned by the device.
157 * @ES58X_EVENT_OK: No errors.
158 * @ES58X_EVENT_CRTL_ACTIVE: Active state: both TR and RX error count
159 *	is less than 128.
160 * @ES58X_EVENT_CRTL_PASSIVE: Passive state: either TX or RX error
161 *	count is greater than 127.
162 * @ES58X_EVENT_CRTL_WARNING: Warning state: either TX or RX error
163 *	count is greater than 96.
164 * @ES58X_EVENT_BUSOFF: Bus off.
165 * @ES58X_EVENT_SINGLE_WIRE: Lost connection on either CAN high or CAN
166 *	low.
167 *
168 * Please refer to ISO 11898-1:2015, section 12.1.4 "Rules of fault
169 * confinement" for additional details.
170 */
171enum es58x_event {
172	ES58X_EVENT_OK = 0,
173	ES58X_EVENT_CRTL_ACTIVE = BIT(0),
174	ES58X_EVENT_CRTL_PASSIVE = BIT(1),
175	ES58X_EVENT_CRTL_WARNING = BIT(2),
176	ES58X_EVENT_BUSOFF = BIT(3),
177	ES58X_EVENT_SINGLE_WIRE = BIT(4)
178};
179
180/* enum es58x_ret_u8 - Device return error codes, 8 bit format.
181 *
182 * Specific to ES581.4.
183 */
184enum es58x_ret_u8 {
185	ES58X_RET_U8_OK = 0x00,
186	ES58X_RET_U8_ERR_UNSPECIFIED_FAILURE = 0x80,
187	ES58X_RET_U8_ERR_NO_MEM = 0x81,
188	ES58X_RET_U8_ERR_BAD_CRC = 0x99
189};
190
191/* enum es58x_ret_u32 - Device return error codes, 32 bit format.
192 */
193enum es58x_ret_u32 {
194	ES58X_RET_U32_OK = 0x00000000UL,
195	ES58X_RET_U32_ERR_UNSPECIFIED_FAILURE = 0x80000000UL,
196	ES58X_RET_U32_ERR_NO_MEM = 0x80004001UL,
197	ES58X_RET_U32_WARN_PARAM_ADJUSTED = 0x40004000UL,
198	ES58X_RET_U32_WARN_TX_MAYBE_REORDER = 0x40004001UL,
199	ES58X_RET_U32_ERR_TIMEDOUT = 0x80000008UL,
200	ES58X_RET_U32_ERR_FIFO_FULL = 0x80003002UL,
201	ES58X_RET_U32_ERR_BAD_CONFIG = 0x80004000UL,
202	ES58X_RET_U32_ERR_NO_RESOURCE = 0x80004002UL
203};
204
205/* enum es58x_ret_type - Type of the command returned by the ES58X
206 *	device.
207 */
208enum es58x_ret_type {
209	ES58X_RET_TYPE_SET_BITTIMING,
210	ES58X_RET_TYPE_ENABLE_CHANNEL,
211	ES58X_RET_TYPE_DISABLE_CHANNEL,
212	ES58X_RET_TYPE_TX_MSG,
213	ES58X_RET_TYPE_RESET_RX,
214	ES58X_RET_TYPE_RESET_TX,
215	ES58X_RET_TYPE_DEVICE_ERR
216};
217
218union es58x_urb_cmd {
219	struct es581_4_urb_cmd es581_4_urb_cmd;
220	struct es58x_fd_urb_cmd es58x_fd_urb_cmd;
221	struct {		/* Common header parts of all variants */
222		__le16 sof;
223		u8 cmd_type;
224		u8 cmd_id;
225	} __packed;
226	DECLARE_FLEX_ARRAY(u8, raw_cmd);
227};
228
229/**
230 * struct es58x_priv - All information specific to a CAN channel.
231 * @can: struct can_priv must be the first member (Socket CAN relies
232 *	on the fact that function netdev_priv() returns a pointer to
233 *	a struct can_priv).
234 * @devlink_port: devlink instance for the network interface.
235 * @es58x_dev: pointer to the corresponding ES58X device.
236 * @tx_urb: Used as a buffer to concatenate the TX messages and to do
237 *	a bulk send. Please refer to es58x_start_xmit() for more
238 *	details.
239 * @tx_tail: Index of the oldest packet still pending for
240 *	completion. @tx_tail & echo_skb_mask represents the beginning
241 *	of the echo skb FIFO, i.e. index of the first element.
242 * @tx_head: Index of the next packet to be sent to the
243 *	device. @tx_head & echo_skb_mask represents the end of the
244 *	echo skb FIFO plus one, i.e. the first free index.
245 * @tx_can_msg_cnt: Number of messages in @tx_urb.
246 * @tx_can_msg_is_fd: false: all messages in @tx_urb are Classical
247 *	CAN, true: all messages in @tx_urb are CAN FD. Rationale:
248 *	ES58X FD devices do not allow to mix Classical CAN and FD CAN
249 *	frames in one single bulk transmission.
250 * @err_passive_before_rtx_success: The ES58X device might enter in a
251 *	state in which it keeps alternating between error passive
252 *	and active states. This counter keeps track of the number of
253 *	error passive and if it gets bigger than
254 *	ES58X_CONSECUTIVE_ERR_PASSIVE_MAX, es58x_rx_err_msg() will
255 *	force the status to bus-off.
256 * @channel_idx: Channel index, starts at zero.
257 */
258struct es58x_priv {
259	struct can_priv can;
260	struct devlink_port devlink_port;
261	struct es58x_device *es58x_dev;
262	struct urb *tx_urb;
263
264	u32 tx_tail;
265	u32 tx_head;
266
267	u8 tx_can_msg_cnt;
268	bool tx_can_msg_is_fd;
269
270	u8 err_passive_before_rtx_success;
271
272	u8 channel_idx;
273};
274
275/**
276 * struct es58x_parameters - Constant parameters of a given hardware
277 *	variant.
278 * @bittiming_const: Nominal bittimming constant parameters.
279 * @data_bittiming_const: Data bittiming constant parameters.
280 * @tdc_const: Transmission Delay Compensation constant parameters.
281 * @bitrate_max: Maximum bitrate supported by the device.
282 * @clock: CAN clock parameters.
283 * @ctrlmode_supported: List of supported modes. Please refer to
284 *	can/netlink.h file for additional details.
285 * @tx_start_of_frame: Magic number at the beginning of each TX URB
286 *	command.
287 * @rx_start_of_frame: Magic number at the beginning of each RX URB
288 *	command.
289 * @tx_urb_cmd_max_len: Maximum length of a TX URB command.
290 * @rx_urb_cmd_max_len: Maximum length of a RX URB command.
291 * @fifo_mask: Bit mask to quickly convert the tx_tail and tx_head
292 *	field of the struct es58x_priv into echo_skb
293 *	indexes. Properties: @fifo_mask = echo_skb_max - 1 where
294 *	echo_skb_max must be a power of two. Also, echo_skb_max must
295 *	not exceed the maximum size of the device internal TX FIFO
296 *	length. This parameter is used to control the network queue
297 *	wake/stop logic.
298 * @dql_min_limit: Dynamic Queue Limits (DQL) absolute minimum limit
299 *	of bytes allowed to be queued on this network device transmit
300 *	queue. Used by the Byte Queue Limits (BQL) to determine how
301 *	frequently the xmit_more flag will be set to true in
302 *	es58x_start_xmit(). Set this value higher to optimize for
303 *	throughput but be aware that it might have a negative impact
304 *	on the latency! This value can also be set dynamically. Please
305 *	refer to Documentation/ABI/testing/sysfs-class-net-queues for
306 *	more details.
307 * @tx_bulk_max: Maximum number of TX messages that can be sent in one
308 *	single URB packet.
309 * @urb_cmd_header_len: Length of the URB command header.
310 * @rx_urb_max: Number of RX URB to be allocated during device probe.
311 * @tx_urb_max: Number of TX URB to be allocated during device probe.
312 */
313struct es58x_parameters {
314	const struct can_bittiming_const *bittiming_const;
315	const struct can_bittiming_const *data_bittiming_const;
316	const struct can_tdc_const *tdc_const;
317	u32 bitrate_max;
318	struct can_clock clock;
319	u32 ctrlmode_supported;
320	u16 tx_start_of_frame;
321	u16 rx_start_of_frame;
322	u16 tx_urb_cmd_max_len;
323	u16 rx_urb_cmd_max_len;
324	u16 fifo_mask;
325	u16 dql_min_limit;
326	u8 tx_bulk_max;
327	u8 urb_cmd_header_len;
328	u8 rx_urb_max;
329	u8 tx_urb_max;
330};
331
332/**
333 * struct es58x_operators - Function pointers used to encode/decode
334 *	the TX/RX messages.
335 * @get_msg_len: Get field msg_len of the urb_cmd. The offset of
336 *	msg_len inside urb_cmd depends of the device model.
337 * @handle_urb_cmd: Decode the URB command received from the device
338 *	and dispatch it to the relevant sub function.
339 * @fill_urb_header: Fill the header of urb_cmd.
340 * @tx_can_msg: Encode a TX CAN message and add it to the bulk buffer
341 *	cmd_buf of es58x_dev.
342 * @enable_channel: Start the CAN channel.
343 * @disable_channel: Stop the CAN channel.
344 * @reset_device: Full reset of the device. N.B: this feature is only
345 *	present on the ES581.4. For ES58X FD devices, this field is
346 *	set to NULL.
347 * @get_timestamp: Request a timestamp from the ES58X device.
348 */
349struct es58x_operators {
350	u16 (*get_msg_len)(const union es58x_urb_cmd *urb_cmd);
351	int (*handle_urb_cmd)(struct es58x_device *es58x_dev,
352			      const union es58x_urb_cmd *urb_cmd);
353	void (*fill_urb_header)(union es58x_urb_cmd *urb_cmd, u8 cmd_type,
354				u8 cmd_id, u8 channel_idx, u16 cmd_len);
355	int (*tx_can_msg)(struct es58x_priv *priv, const struct sk_buff *skb);
356	int (*enable_channel)(struct es58x_priv *priv);
357	int (*disable_channel)(struct es58x_priv *priv);
358	int (*reset_device)(struct es58x_device *es58x_dev);
359	int (*get_timestamp)(struct es58x_device *es58x_dev);
360};
361
362/**
363 * struct es58x_sw_version - Version number of the firmware or the
364 *	bootloader.
365 * @major: Version major number, represented on two digits.
366 * @minor: Version minor number, represented on two digits.
367 * @revision: Version revision number, represented on two digits.
368 *
369 * The firmware and the bootloader share the same format: "xx.xx.xx"
370 * where 'x' is a digit. Both can be retrieved from the product
371 * information string.
372 */
373struct es58x_sw_version {
374	u8 major;
375	u8 minor;
376	u8 revision;
377};
378
379/**
380 * struct es58x_hw_revision - Hardware revision number.
381 * @letter: Revision letter, an alphanumeric character.
382 * @major: Version major number, represented on three digits.
383 * @minor: Version minor number, represented on three digits.
384 *
385 * The hardware revision uses its own format: "axxx/xxx" where 'a' is
386 * an alphanumeric character and 'x' a digit. It can be retrieved from
387 * the product information string.
388 */
389struct es58x_hw_revision {
390	char letter;
391	u16 major;
392	u16 minor;
393};
394
395/**
396 * struct es58x_device - All information specific to an ES58X device.
397 * @dev: Device information.
398 * @udev: USB device information.
399 * @netdev: Array of our CAN channels.
400 * @param: The constant parameters.
401 * @ops: Operators.
402 * @rx_pipe: USB reception pipe.
403 * @tx_pipe: USB transmission pipe.
404 * @rx_urbs: Anchor for received URBs.
405 * @tx_urbs_busy: Anchor for TX URBs which were send to the device.
406 * @tx_urbs_idle: Anchor for TX USB which are idle. This driver
407 *	allocates the memory for the URBs during the probe. When a TX
408 *	URB is needed, it can be taken from this anchor. The network
409 *	queue wake/stop logic should prevent this URB from getting
410 *	empty. Please refer to es58x_get_tx_urb() for more details.
411 * @tx_urbs_idle_cnt: number of urbs in @tx_urbs_idle.
412 * @firmware_version: The firmware version number.
413 * @bootloader_version: The bootloader version number.
414 * @hardware_revision: The hardware revision number.
415 * @ktime_req_ns: kernel timestamp when es58x_set_realtime_diff_ns()
416 *	was called.
417 * @realtime_diff_ns: difference in nanoseconds between the clocks of
418 *	the ES58X device and the kernel.
419 * @timestamps: a temporary buffer to store the time stamps before
420 *	feeding them to es58x_can_get_echo_skb(). Can only be used
421 *	in RX branches.
422 * @num_can_ch: Number of CAN channel (i.e. number of elements of @netdev).
423 * @opened_channel_cnt: number of channels opened. Free of race
424 *	conditions because its two users (net_device_ops:ndo_open()
425 *	and net_device_ops:ndo_close()) guarantee that the network
426 *	stack big kernel lock (a.k.a. rtnl_mutex) is being hold.
427 * @rx_cmd_buf_len: Length of @rx_cmd_buf.
428 * @rx_cmd_buf: The device might split the URB commands in an
429 *	arbitrary amount of pieces. This buffer is used to concatenate
430 *	all those pieces. Can only be used in RX branches. This field
431 *	has to be the last one of the structure because it is has a
432 *	flexible size (c.f. es58x_sizeof_es58x_device() function).
433 */
434struct es58x_device {
435	struct device *dev;
436	struct usb_device *udev;
437	struct net_device *netdev[ES58X_NUM_CAN_CH_MAX];
438
439	const struct es58x_parameters *param;
440	const struct es58x_operators *ops;
441
442	unsigned int rx_pipe;
443	unsigned int tx_pipe;
444
445	struct usb_anchor rx_urbs;
446	struct usb_anchor tx_urbs_busy;
447	struct usb_anchor tx_urbs_idle;
448	atomic_t tx_urbs_idle_cnt;
449
450	struct es58x_sw_version firmware_version;
451	struct es58x_sw_version bootloader_version;
452	struct es58x_hw_revision hardware_revision;
453
454	u64 ktime_req_ns;
455	s64 realtime_diff_ns;
456
457	u64 timestamps[ES58X_ECHO_BULK_MAX];
458
459	u8 num_can_ch;
460	u8 opened_channel_cnt;
461
462	u16 rx_cmd_buf_len;
463	union es58x_urb_cmd rx_cmd_buf;
464};
465
466/**
467 * es58x_sizeof_es58x_device() - Calculate the maximum length of
468 *	struct es58x_device.
469 * @es58x_dev_param: The constant parameters of the device.
470 *
471 * The length of struct es58x_device depends on the length of its last
472 * field: rx_cmd_buf. This macro allows to optimize the memory
473 * allocation.
474 *
475 * Return: length of struct es58x_device.
476 */
477static inline size_t es58x_sizeof_es58x_device(const struct es58x_parameters
478					       *es58x_dev_param)
479{
480	return offsetof(struct es58x_device, rx_cmd_buf) +
481		es58x_dev_param->rx_urb_cmd_max_len;
482}
483
484static inline int __es58x_check_msg_len(const struct device *dev,
485					const char *stringified_msg,
486					size_t actual_len, size_t expected_len)
487{
488	if (expected_len != actual_len) {
489		dev_err(dev,
490			"Length of %s is %zu but received command is %zu.\n",
491			stringified_msg, expected_len, actual_len);
492		return -EMSGSIZE;
493	}
494	return 0;
495}
496
497/**
498 * es58x_check_msg_len() - Check the size of a received message.
499 * @dev: Device, used to print error messages.
500 * @msg: Received message, must not be a pointer.
501 * @actual_len: Length of the message as advertised in the command header.
502 *
503 * Must be a macro in order to accept the different types of messages
504 * as an input. Can be use with any of the messages which have a fixed
505 * length. Check for an exact match of the size.
506 *
507 * Return: zero on success, -EMSGSIZE if @actual_len differs from the
508 * expected length.
509 */
510#define es58x_check_msg_len(dev, msg, actual_len)			\
511	__es58x_check_msg_len(dev, __stringify(msg),			\
512			      actual_len, sizeof(msg))
513
514static inline int __es58x_check_msg_max_len(const struct device *dev,
515					    const char *stringified_msg,
516					    size_t actual_len,
517					    size_t expected_len)
518{
519	if (actual_len > expected_len) {
520		dev_err(dev,
521			"Maximum length for %s is %zu but received command is %zu.\n",
522			stringified_msg, expected_len, actual_len);
523		return -EOVERFLOW;
524	}
525	return 0;
526}
527
528/**
529 * es58x_check_msg_max_len() - Check the maximum size of a received message.
530 * @dev: Device, used to print error messages.
531 * @msg: Received message, must not be a pointer.
532 * @actual_len: Length of the message as advertised in the command header.
533 *
534 * Must be a macro in order to accept the different types of messages
535 * as an input. To be used with the messages of variable sizes. Only
536 * check that the message is not bigger than the maximum expected
537 * size.
538 *
539 * Return: zero on success, -EOVERFLOW if @actual_len is greater than
540 * the expected length.
541 */
542#define es58x_check_msg_max_len(dev, msg, actual_len)			\
543	__es58x_check_msg_max_len(dev, __stringify(msg),		\
544				  actual_len, sizeof(msg))
545
546static inline int __es58x_msg_num_element(const struct device *dev,
547					  const char *stringified_msg,
548					  size_t actual_len, size_t msg_len,
549					  size_t elem_len)
550{
551	size_t actual_num_elem = actual_len / elem_len;
552	size_t expected_num_elem = msg_len / elem_len;
553
554	if (actual_num_elem == 0) {
555		dev_err(dev,
556			"Minimum length for %s is %zu but received command is %zu.\n",
557			stringified_msg, elem_len, actual_len);
558		return -EMSGSIZE;
559	} else if ((actual_len % elem_len) != 0) {
560		dev_err(dev,
561			"Received command length: %zu is not a multiple of %s[0]: %zu\n",
562			actual_len, stringified_msg, elem_len);
563		return -EMSGSIZE;
564	} else if (actual_num_elem > expected_num_elem) {
565		dev_err(dev,
566			"Array %s is supposed to have %zu elements each of size %zu...\n",
567			stringified_msg, expected_num_elem, elem_len);
568		dev_err(dev,
569			"... But received command has %zu elements (total length %zu).\n",
570			actual_num_elem, actual_len);
571		return -EOVERFLOW;
572	}
573	return actual_num_elem;
574}
575
576/**
577 * es58x_msg_num_element() - Check size and give the number of
578 *	elements in a message of array type.
579 * @dev: Device, used to print error messages.
580 * @msg: Received message, must be an array.
581 * @actual_len: Length of the message as advertised in the command
582 *	header.
583 *
584 * Must be a macro in order to accept the different types of messages
585 * as an input. To be used on message of array type. Array's element
586 * has to be of fixed size (else use es58x_check_msg_max_len()). Check
587 * that the total length is an exact multiple of the length of a
588 * single element.
589 *
590 * Return: number of elements in the array on success, -EOVERFLOW if
591 * @actual_len is greater than the expected length, -EMSGSIZE if
592 * @actual_len is not a multiple of a single element.
593 */
594#define es58x_msg_num_element(dev, msg, actual_len)			\
595({									\
596	size_t __elem_len = sizeof((msg)[0]) + __must_be_array(msg);	\
597	__es58x_msg_num_element(dev, __stringify(msg), actual_len,	\
598				sizeof(msg), __elem_len);		\
599})
600
601/**
602 * es58x_priv() - Get the priv member and cast it to struct es58x_priv.
603 * @netdev: CAN network device.
604 *
605 * Return: ES58X device.
606 */
607static inline struct es58x_priv *es58x_priv(struct net_device *netdev)
608{
609	return (struct es58x_priv *)netdev_priv(netdev);
610}
611
612/**
613 * ES58X_SIZEOF_URB_CMD() - Calculate the maximum length of an urb
614 *	command for a given message field name.
615 * @es58x_urb_cmd_type: type (either "struct es581_4_urb_cmd" or
616 *	"struct es58x_fd_urb_cmd").
617 * @msg_field: name of the message field.
618 *
619 * Must be a macro in order to accept the different command types as
620 * an input.
621 *
622 * Return: length of the urb command.
623 */
624#define ES58X_SIZEOF_URB_CMD(es58x_urb_cmd_type, msg_field)		\
625	(offsetof(es58x_urb_cmd_type, raw_msg)				\
626		+ sizeof_field(es58x_urb_cmd_type, msg_field)		\
627		+ sizeof_field(es58x_urb_cmd_type,			\
628			       reserved_for_crc16_do_not_use))
629
630/**
631 * es58x_get_urb_cmd_len() - Calculate the actual length of an urb
632 *	command for a given message length.
633 * @es58x_dev: ES58X device.
634 * @msg_len: Length of the message.
635 *
636 * Add the header and CRC lengths to the message length.
637 *
638 * Return: length of the urb command.
639 */
640static inline size_t es58x_get_urb_cmd_len(struct es58x_device *es58x_dev,
641					   u16 msg_len)
642{
643	return es58x_dev->param->urb_cmd_header_len + msg_len + sizeof(u16);
644}
645
646/**
647 * es58x_get_netdev() - Get the network device.
648 * @es58x_dev: ES58X device.
649 * @channel_no: The channel number as advertised in the urb command.
650 * @channel_idx_offset: Some of the ES58x starts channel numbering
651 *	from 0 (ES58X FD), others from 1 (ES581.4).
652 * @netdev: CAN network device.
653 *
654 * Do a sanity check on the index provided by the device.
655 *
656 * Return: zero on success, -ECHRNG if the received channel number is
657 *	out of range and -ENODEV if the network device is not yet
658 *	configured.
659 */
660static inline int es58x_get_netdev(struct es58x_device *es58x_dev,
661				   int channel_no, int channel_idx_offset,
662				   struct net_device **netdev)
663{
664	int channel_idx = channel_no - channel_idx_offset;
665
666	*netdev = NULL;
667	if (channel_idx < 0 || channel_idx >= es58x_dev->num_can_ch)
668		return -ECHRNG;
669
670	*netdev = es58x_dev->netdev[channel_idx];
671	if (!*netdev || !netif_device_present(*netdev))
672		return -ENODEV;
673
674	return 0;
675}
676
677/**
678 * es58x_get_raw_can_id() - Get the CAN ID.
679 * @cf: CAN frame.
680 *
681 * Mask the CAN ID in order to only keep the significant bits.
682 *
683 * Return: the raw value of the CAN ID.
684 */
685static inline int es58x_get_raw_can_id(const struct can_frame *cf)
686{
687	if (cf->can_id & CAN_EFF_FLAG)
688		return cf->can_id & CAN_EFF_MASK;
689	else
690		return cf->can_id & CAN_SFF_MASK;
691}
692
693/**
694 * es58x_get_flags() - Get the CAN flags.
695 * @skb: socket buffer of a CAN message.
696 *
697 * Return: the CAN flag as an enum es58x_flag.
698 */
699static inline enum es58x_flag es58x_get_flags(const struct sk_buff *skb)
700{
701	struct canfd_frame *cf = (struct canfd_frame *)skb->data;
702	enum es58x_flag es58x_flags = 0;
703
704	if (cf->can_id & CAN_EFF_FLAG)
705		es58x_flags |= ES58X_FLAG_EFF;
706
707	if (can_is_canfd_skb(skb)) {
708		es58x_flags |= ES58X_FLAG_FD_DATA;
709		if (cf->flags & CANFD_BRS)
710			es58x_flags |= ES58X_FLAG_FD_BRS;
711		if (cf->flags & CANFD_ESI)
712			es58x_flags |= ES58X_FLAG_FD_ESI;
713	} else if (cf->can_id & CAN_RTR_FLAG)
714		/* Remote frames are only defined in Classical CAN frames */
715		es58x_flags |= ES58X_FLAG_RTR;
716
717	return es58x_flags;
718}
719
720/* es58x_core.c. */
721int es58x_can_get_echo_skb(struct net_device *netdev, u32 packet_idx,
722			   u64 *tstamps, unsigned int pkts);
723int es58x_tx_ack_msg(struct net_device *netdev, u16 tx_free_entries,
724		     enum es58x_ret_u32 rx_cmd_ret_u32);
725int es58x_rx_can_msg(struct net_device *netdev, u64 timestamp, const u8 *data,
726		     canid_t can_id, enum es58x_flag es58x_flags, u8 dlc);
727int es58x_rx_err_msg(struct net_device *netdev, enum es58x_err error,
728		     enum es58x_event event, u64 timestamp);
729void es58x_rx_timestamp(struct es58x_device *es58x_dev, u64 timestamp);
730int es58x_rx_cmd_ret_u8(struct device *dev, enum es58x_ret_type cmd_ret_type,
731			enum es58x_ret_u8 rx_cmd_ret_u8);
732int es58x_rx_cmd_ret_u32(struct net_device *netdev,
733			 enum es58x_ret_type cmd_ret_type,
734			 enum es58x_ret_u32 rx_cmd_ret_u32);
735int es58x_send_msg(struct es58x_device *es58x_dev, u8 cmd_type, u8 cmd_id,
736		   const void *msg, u16 cmd_len, int channel_idx);
737
738/* es58x_devlink.c. */
739void es58x_parse_product_info(struct es58x_device *es58x_dev);
740extern const struct devlink_ops es58x_dl_ops;
741
742/* es581_4.c. */
743extern const struct es58x_parameters es581_4_param;
744extern const struct es58x_operators es581_4_ops;
745
746/* es58x_fd.c. */
747extern const struct es58x_parameters es58x_fd_param;
748extern const struct es58x_operators es58x_fd_ops;
749
750#endif /* __ES58X_COMMON_H__ */