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|
/* SocketCAN driver for Microchip CAN BUS Analyzer Tool
*
* Copyright (C) 2017 Mobica Limited
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published
* by the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program.
*
* This driver is inspired by the 4.6.2 version of net/can/usb/usb_8dev.c
*/
#include <asm/unaligned.h>
#include <linux/can.h>
#include <linux/can/dev.h>
#include <linux/can/error.h>
#include <linux/can/led.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/signal.h>
#include <linux/slab.h>
#include <linux/usb.h>
/* vendor and product id */
#define MCBA_MODULE_NAME "mcba_usb"
#define MCBA_VENDOR_ID 0x04d8
#define MCBA_PRODUCT_ID 0x0a30
/* driver constants */
#define MCBA_MAX_RX_URBS 20
#define MCBA_MAX_TX_URBS 20
#define MCBA_CTX_FREE MCBA_MAX_TX_URBS
/* RX buffer must be bigger than msg size since at the
* beggining USB messages are stacked.
*/
#define MCBA_USB_RX_BUFF_SIZE 64
#define MCBA_USB_TX_BUFF_SIZE (sizeof(struct mcba_usb_msg))
/* MCBA endpoint numbers */
#define MCBA_USB_EP_IN 1
#define MCBA_USB_EP_OUT 1
/* Microchip command id */
#define MBCA_CMD_RECEIVE_MESSAGE 0xE3
#define MBCA_CMD_I_AM_ALIVE_FROM_CAN 0xF5
#define MBCA_CMD_I_AM_ALIVE_FROM_USB 0xF7
#define MBCA_CMD_CHANGE_BIT_RATE 0xA1
#define MBCA_CMD_TRANSMIT_MESSAGE_EV 0xA3
#define MBCA_CMD_SETUP_TERMINATION_RESISTANCE 0xA8
#define MBCA_CMD_READ_FW_VERSION 0xA9
#define MBCA_CMD_NOTHING_TO_SEND 0xFF
#define MBCA_CMD_TRANSMIT_MESSAGE_RSP 0xE2
#define MCBA_VER_REQ_USB 1
#define MCBA_VER_REQ_CAN 2
#define MCBA_SIDL_EXID_MASK 0x8
#define MCBA_DLC_MASK 0xf
#define MCBA_DLC_RTR_MASK 0x40
#define MCBA_CAN_STATE_WRN_TH 95
#define MCBA_CAN_STATE_ERR_PSV_TH 127
#define MCBA_TERMINATION_DISABLED CAN_TERMINATION_DISABLED
#define MCBA_TERMINATION_ENABLED 120
struct mcba_usb_ctx {
struct mcba_priv *priv;
u32 ndx;
u8 dlc;
bool can;
};
/* Structure to hold all of our device specific stuff */
struct mcba_priv {
struct can_priv can; /* must be the first member */
struct sk_buff *echo_skb[MCBA_MAX_TX_URBS];
struct mcba_usb_ctx tx_context[MCBA_MAX_TX_URBS];
struct usb_device *udev;
struct net_device *netdev;
struct usb_anchor tx_submitted;
struct usb_anchor rx_submitted;
struct can_berr_counter bec;
bool usb_ka_first_pass;
bool can_ka_first_pass;
bool can_speed_check;
atomic_t free_ctx_cnt;
};
/* CAN frame */
struct __packed mcba_usb_msg_can {
u8 cmd_id;
__be16 eid;
__be16 sid;
u8 dlc;
u8 data[8];
u8 timestamp[4];
u8 checksum;
};
/* command frame */
struct __packed mcba_usb_msg {
u8 cmd_id;
u8 unused[18];
};
struct __packed mcba_usb_msg_ka_usb {
u8 cmd_id;
u8 termination_state;
u8 soft_ver_major;
u8 soft_ver_minor;
u8 unused[15];
};
struct __packed mcba_usb_msg_ka_can {
u8 cmd_id;
u8 tx_err_cnt;
u8 rx_err_cnt;
u8 rx_buff_ovfl;
u8 tx_bus_off;
__be16 can_bitrate;
__le16 rx_lost;
u8 can_stat;
u8 soft_ver_major;
u8 soft_ver_minor;
u8 debug_mode;
u8 test_complete;
u8 test_result;
u8 unused[4];
};
struct __packed mcba_usb_msg_change_bitrate {
u8 cmd_id;
__be16 bitrate;
u8 unused[16];
};
struct __packed mcba_usb_msg_termination {
u8 cmd_id;
u8 termination;
u8 unused[17];
};
struct __packed mcba_usb_msg_fw_ver {
u8 cmd_id;
u8 pic;
u8 unused[17];
};
static const struct usb_device_id mcba_usb_table[] = {
{ USB_DEVICE(MCBA_VENDOR_ID, MCBA_PRODUCT_ID) },
{} /* Terminating entry */
};
MODULE_DEVICE_TABLE(usb, mcba_usb_table);
static const u16 mcba_termination[] = { MCBA_TERMINATION_DISABLED,
MCBA_TERMINATION_ENABLED };
static const u32 mcba_bitrate[] = { 20000, 33333, 50000, 80000, 83333,
100000, 125000, 150000, 175000, 200000,
225000, 250000, 275000, 300000, 500000,
625000, 800000, 1000000 };
static inline void mcba_init_ctx(struct mcba_priv *priv)
{
int i = 0;
for (i = 0; i < MCBA_MAX_TX_URBS; i++) {
priv->tx_context[i].ndx = MCBA_CTX_FREE;
priv->tx_context[i].priv = priv;
}
atomic_set(&priv->free_ctx_cnt, ARRAY_SIZE(priv->tx_context));
}
static inline struct mcba_usb_ctx *mcba_usb_get_free_ctx(struct mcba_priv *priv,
struct can_frame *cf)
{
int i = 0;
struct mcba_usb_ctx *ctx = NULL;
for (i = 0; i < MCBA_MAX_TX_URBS; i++) {
if (priv->tx_context[i].ndx == MCBA_CTX_FREE) {
ctx = &priv->tx_context[i];
ctx->ndx = i;
if (cf) {
ctx->can = true;
ctx->dlc = cf->can_dlc;
} else {
ctx->can = false;
ctx->dlc = 0;
}
atomic_dec(&priv->free_ctx_cnt);
break;
}
}
if (!atomic_read(&priv->free_ctx_cnt))
/* That was the last free ctx. Slow down tx path */
netif_stop_queue(priv->netdev);
return ctx;
}
/* mcba_usb_free_ctx and mcba_usb_get_free_ctx are executed by different
* threads. The order of execution in below function is important.
*/
static inline void
|