path: root/drivers/net/can/usb/esd_usb.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * CAN driver for esd electronics gmbh CAN-USB/2, CAN-USB/3 and CAN-USB/Micro
 *
 * Copyright (C) 2010-2012 esd electronic system design gmbh, Matthias Fuchs <socketcan@esd.eu>
 * Copyright (C) 2022-2023 esd electronics gmbh, Frank Jungclaus <frank.jungclaus@esd.eu>
 */

#include <linux/can.h>
#include <linux/can/dev.h>
#include <linux/can/error.h>
#include <linux/ethtool.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/signal.h>
#include <linux/slab.h>
#include <linux/units.h>
#include <linux/usb.h>

MODULE_AUTHOR("Matthias Fuchs <socketcan@esd.eu>");
MODULE_AUTHOR("Frank Jungclaus <frank.jungclaus@esd.eu>");
MODULE_DESCRIPTION("CAN driver for esd electronics gmbh CAN-USB/2, CAN-USB/3 and CAN-USB/Micro interfaces");
MODULE_LICENSE("GPL v2");

/* USB vendor and product ID */
#define ESD_USB_ESDGMBH_VENDOR_ID	0x0ab4
#define ESD_USB_CANUSB2_PRODUCT_ID	0x0010
#define ESD_USB_CANUSBM_PRODUCT_ID	0x0011
#define ESD_USB_CANUSB3_PRODUCT_ID	0x0014

/* CAN controller clock frequencies */
#define ESD_USB_2_CAN_CLOCK	(60 * MEGA) /* Hz */
#define ESD_USB_M_CAN_CLOCK	(36 * MEGA) /* Hz */
#define ESD_USB_3_CAN_CLOCK	(80 * MEGA) /* Hz */

/* Maximum number of CAN nets */
#define ESD_USB_MAX_NETS	2

/* USB commands */
#define ESD_USB_CMD_VERSION		1 /* also used for VERSION_REPLY */
#define ESD_USB_CMD_CAN_RX		2 /* device to host only */
#define ESD_USB_CMD_CAN_TX		3 /* also used for TX_DONE */
#define ESD_USB_CMD_SETBAUD		4 /* also used for SETBAUD_REPLY */
#define ESD_USB_CMD_TS			5 /* also used for TS_REPLY */
#define ESD_USB_CMD_IDADD		6 /* also used for IDADD_REPLY */

/* esd CAN message flags - dlc field */
#define ESD_USB_RTR	BIT(4)
#define ESD_USB_NO_BRS	BIT(4)
#define ESD_USB_ESI	BIT(5)
#define ESD_USB_FD	BIT(7)

/* esd CAN message flags - id field */
#define ESD_USB_EXTID	BIT(29)
#define ESD_USB_EVENT	BIT(30)
#define ESD_USB_IDMASK	GENMASK(28, 0)

/* esd CAN event ids */
#define ESD_USB_EV_CAN_ERROR_EXT	2 /* CAN controller specific diagnostic data */

/* baudrate message flags */
#define ESD_USB_LOM	BIT(30) /* Listen Only Mode */
#define ESD_USB_UBR	BIT(31) /* User Bit Rate (controller BTR) in bits 0..27 */
#define ESD_USB_NO_BAUDRATE	GENMASK(30, 0) /* bit rate unconfigured */

/* bit timing esd CAN-USB */
#define ESD_USB_2_TSEG1_SHIFT	16
#define ESD_USB_2_TSEG2_SHIFT	20
#define ESD_USB_2_SJW_SHIFT	14
#define ESD_USB_M_SJW_SHIFT	24
#define ESD_USB_TRIPLE_SAMPLES	BIT(23)

/* Transmitter Delay Compensation */
#define ESD_USB_3_TDC_MODE_AUTO	0

/* esd IDADD message */
#define ESD_USB_ID_ENABLE	BIT(7)
#define ESD_USB_MAX_ID_SEGMENT	64

/* SJA1000 ECC register (emulated by usb firmware) */
#define ESD_USB_SJA1000_ECC_SEG		GENMASK(4, 0)
#define ESD_USB_SJA1000_ECC_DIR		BIT(5)
#define ESD_USB_SJA1000_ECC_ERR		BIT(2, 1)
#define ESD_USB_SJA1000_ECC_BIT		0x00
#define ESD_USB_SJA1000_ECC_FORM	BIT(6)
#define ESD_USB_SJA1000_ECC_STUFF	BIT(7)
#define ESD_USB_SJA1000_ECC_MASK	GENMASK(7, 6)

/* esd bus state event codes */
#define ESD_USB_BUSSTATE_MASK	GENMASK(7, 6)
#define ESD_USB_BUSSTATE_WARN	BIT(6)
#define ESD_USB_BUSSTATE_ERRPASSIVE	BIT(7)
#define ESD_USB_BUSSTATE_BUSOFF	GENMASK(7, 6)

#define ESD_USB_RX_BUFFER_SIZE		1024
#define ESD_USB_MAX_RX_URBS		4
#define ESD_USB_MAX_TX_URBS		16 /* must be power of 2 */

/* Modes for CAN-USB/3, to be used for esd_usb_3_set_baudrate_msg_x.mode */
#define ESD_USB_3_BAUDRATE_MODE_DISABLE		0 /* remove from bus */
#define ESD_USB_3_BAUDRATE_MODE_INDEX		1 /* ESD (CiA) bit rate idx */
#define ESD_USB_3_BAUDRATE_MODE_BTR_CTRL	2 /* BTR values (controller)*/
#define ESD_USB_3_BAUDRATE_MODE_BTR_CANONICAL	3 /* BTR values (canonical) */
#define ESD_USB_3_BAUDRATE_MODE_NUM		4 /* numerical bit rate */
#define ESD_USB_3_BAUDRATE_MODE_AUTOBAUD	5 /* autobaud */

/* Flags for CAN-USB/3, to be used for esd_usb_3_set_baudrate_msg_x.flags */
#define ESD_USB_3_BAUDRATE_FLAG_FD	BIT(0) /* enable CAN FD mode */
#define ESD_USB_3_BAUDRATE_FLAG_LOM	BIT(1) /* enable listen only mode */
#define ESD_USB_3_BAUDRATE_FLAG_STM	BIT(2) /* enable self test mode */
#define ESD_USB_3_BAUDRATE_FLAG_TRS	BIT(3) /* enable triple sampling */
#define ESD_USB_3_BAUDRATE_FLAG_TXP	BIT(4) /* enable t