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

// SPDX-License-Identifier: GPL-2.0-only
/* CAN driver for Geschwister Schneider USB/CAN devices
 * and bytewerk.org candleLight USB CAN interfaces.
 *
 * Copyright (C) 2013-2016 Geschwister Schneider Technologie-,
 * Entwicklungs- und Vertriebs UG (Haftungsbeschränkt).
 * Copyright (C) 2016 Hubert Denkmair
 *
 * Many thanks to all socketcan devs!
 */

#include <linux/bitfield.h>
#include <linux/ethtool.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/signal.h>
#include <linux/usb.h>

#include <linux/can.h>
#include <linux/can/dev.h>
#include <linux/can/error.h>

/* Device specific constants */
#define USB_GSUSB_1_VENDOR_ID 0x1d50
#define USB_GSUSB_1_PRODUCT_ID 0x606f

#define USB_CANDLELIGHT_VENDOR_ID 0x1209
#define USB_CANDLELIGHT_PRODUCT_ID 0x2323

#define GSUSB_ENDPOINT_IN 1
#define GSUSB_ENDPOINT_OUT 2

/* Device specific constants */
enum gs_usb_breq {
	GS_USB_BREQ_HOST_FORMAT = 0,
	GS_USB_BREQ_BITTIMING,
	GS_USB_BREQ_MODE,
	GS_USB_BREQ_BERR,
	GS_USB_BREQ_BT_CONST,
	GS_USB_BREQ_DEVICE_CONFIG,
	GS_USB_BREQ_TIMESTAMP,
	GS_USB_BREQ_IDENTIFY,
	GS_USB_BREQ_GET_USER_ID,
	GS_USB_BREQ_QUIRK_CANTACT_PRO_DATA_BITTIMING = GS_USB_BREQ_GET_USER_ID,
	GS_USB_BREQ_SET_USER_ID,
	GS_USB_BREQ_DATA_BITTIMING,
};

enum gs_can_mode {
	/* reset a channel. turns it off */
	GS_CAN_MODE_RESET = 0,
	/* starts a channel */
	GS_CAN_MODE_START
};

enum gs_can_state {
	GS_CAN_STATE_ERROR_ACTIVE = 0,
	GS_CAN_STATE_ERROR_WARNING,
	GS_CAN_STATE_ERROR_PASSIVE,
	GS_CAN_STATE_BUS_OFF,
	GS_CAN_STATE_STOPPED,
	GS_CAN_STATE_SLEEPING
};

enum gs_can_identify_mode {
	GS_CAN_IDENTIFY_OFF = 0,
	GS_CAN_IDENTIFY_ON
};

/* data types passed between host and device */

/* The firmware on the original USB2CAN by Geschwister Schneider
 * Technologie Entwicklungs- und Vertriebs UG exchanges all data
 * between the host and the device in host byte order. This is done
 * with the struct gs_host_config::byte_order member, which is sent
 * first to indicate the desired byte order.
 *
 * The widely used open source firmware candleLight doesn't support
 * this feature and exchanges the data in little endian byte order.
 */
struct gs_host_config {
	__le32 byte_order;
} __packed;

struct gs_device_config {
	u8 reserved1;
	u8 reserved2;
	u8 reserved3;
	u8 icount;
	__le32 sw_version;
	__le32 hw_version;
} __packed;

#define GS_CAN_MODE_NORMAL 0
#define GS_CAN_MODE_LISTEN_ONLY BIT(0)
#define GS_CAN_MODE_LOOP_BACK BIT(1)
#define GS_CAN_MODE_TRIPLE_SAMPLE BIT(2)
#define GS_CAN_MODE_ONE_SHOT BIT(3)
#define GS_CAN_MODE_HW_TIMESTAMP BIT(4)
/* GS_CAN_FEATURE_IDENTIFY BIT(5) */
/* GS_CAN_FEATURE_USER_ID BIT(6) */
#define GS_CAN_MODE_PAD_PKTS_TO_MAX_PKT_SIZE BIT(7)
#define GS_CAN_MODE_FD BIT(8)
/* GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX BIT(9) */

struct gs_device_mode {
	__le32 mode;
	__le32 flags;
} __packed;

struct gs_device_state {
	__le32 state;
	__le32 rxerr;
	__le32 txerr;
} __packed;

struct gs_device_bittiming {
	__le32 prop_seg;
	__le32 phase_seg1;
	__le32 phase_seg2;
	__le32 sjw;
	__le32 brp;
} __packed;

struct gs_identify_mode {
	__le32 mode;
} __packed;

#define GS_CAN_FEATURE_LISTEN_ONLY BIT(0)
#define GS_CAN_FEATURE_LOOP_BACK BIT(1)
#define GS_CAN_FEATURE_TRIPLE_SAMPLE BIT(2)
#define GS_CAN_FEATURE_ONE_SHOT BIT(3)
#define GS_CAN_FEATURE_HW_TIMESTAMP BIT(4)
#define GS_CAN_FEATURE_IDENTIFY BIT(5)
#define GS_CAN_FEATURE_USER_ID BIT(6)
#define GS_CAN_FEATURE_PAD_PKTS_TO_MAX_PKT_SIZE BIT(7)
#define GS_CAN_FEATURE_FD BIT(8)
#define GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX BIT(9)
#define GS_CAN_FEATURE_MASK GENMASK(9, 0)

/* internal quirks - keep in GS_CAN_FEATURE space for now */

/* CANtact Pro original firmware:
 * BREQ DATA_BITTIMING overlaps with GET_USER_ID
 */
#define GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO BIT(31)

struct gs_device_bt_const {
	__le32 feature;
	__le32 fclk_can;
	__le32 tseg1_min;
	__le32 tseg1_max;
	__le32 tseg2_min;
	__le32 tseg2_max;
	__le32 sjw_max;
	__le32 brp_min;
	__le32 brp_max;
	__le32 brp_inc;
} __packed;

#define GS_CAN_FLAG_OVERFLOW BIT(0)
#define GS_CAN_FLAG_FD BIT(1)
#define GS_CAN_FLAG_BRS BIT(2)
#define GS_CAN_FLAG_ESI BIT(3)

struct classic_can {
	u8 data[8];
} __packed;

struct classic_can_quirk {
	u8 data[8];
	u8 quirk;
} __packed;

struct canfd {
	u8 data[64];
} __packed;

struct canfd_quirk {
	u8 data[64];
	u8 quirk;
} __packed;

struct gs_host_frame {
	u32 echo_id;
	__le32 can_id;

	u8 can_dlc;
	u8 channel;
	u8 flags;
	u8 reserved;

	union {
		DECLARE_FLEX_ARRAY(struct classic_can, classic_can);
		DECLARE_FLEX_ARRAY(struct classic_can_quirk, classic_can_quirk);
		DECLARE_FLEX_ARRAY(struct canfd, canfd);
		DECLARE_FLEX_ARRAY(struct canfd_quirk, canfd_quirk);
	};
} __packed;
/* The GS USB devices make use of the same flags and masks as in
 * linux/can.h and linux/can/error.h, and no additional mapping is necessary.
 */

/* Only send a max of GS_MAX_TX_URBS frames per channel at a time. */
#define GS_MAX_TX_URBS 10
/* Only launch a max of GS_MAX_RX_URBS usb requests at a time. */
#define GS_MAX_RX_URBS 30
/* Maximum number of interfaces the driver supports per device.
 * Current hardware only supports 3 interfaces. The future may vary.
 */
#define GS_MAX_INTF 3

struct gs_tx_context {
	struct gs_can *dev;
	unsigned int echo_id;
};

struct gs_can {
	struct can_priv can; /* must be the first member */

	struct gs_usb *parent;

	struct net_device *netdev;
	struct usb_device *udev;
	struct usb_interface *iface