From 51f3baad7de943780ce0c17bd7975df567dd6e14 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Remigiusz=20Ko=C5=82=C5=82=C4=85taj?= Date: Fri, 14 Apr 2017 20:32:28 +0200 Subject: [PATCH] can: mcba_usb: Add support for Microchip CAN BUS Analyzer MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit SocketCAN driver for Microchip CAN BUS Analyzer (http://www.microchip.com/development-tools/) Changes in v4: - possible memory leak fixed in mcba_usb_write_bulk_callback - LED support added - failure handling in mcba_usb_probe improved - C99 initializers for structs on stack Changes in v3: - improved/simplified CAN ID conversion - functions for transmission of skb and cmd separated - fixed/improved netif_stop_queue handling - style/cosmetic corrections Changes in v2: - Termination handling reimplemented to fit new netlink API (IFLA_CAN_TERMINATION) - Bitrate handling reimplemented to fit new netlink API (IFLA_CAN_BITRATE) - CAN ID conversion refactored (changed from macro to inline functions) - CAN DLC handling using get_can_dlc() - Endianness handling for can_speed introduced - Debugging removed - Redundant error prints removed - Style/cosmetic corrections (i.e. macro names, redefs, inits etc.) Signed-off-by: Remigiusz Kołłątaj Signed-off-by: Marc Kleine-Budde --- drivers/net/can/usb/Kconfig | 6 + drivers/net/can/usb/Makefile | 1 + drivers/net/can/usb/mcba_usb.c | 904 +++++++++++++++++++++++++++++++++ 3 files changed, 911 insertions(+) create mode 100644 drivers/net/can/usb/mcba_usb.c diff --git a/drivers/net/can/usb/Kconfig b/drivers/net/can/usb/Kconfig index 8483a40e7e9e..2d0313eb31c0 100644 --- a/drivers/net/can/usb/Kconfig +++ b/drivers/net/can/usb/Kconfig @@ -81,4 +81,10 @@ config CAN_8DEV_USB This driver supports the USB2CAN interface from 8 devices (http://www.8devices.com). +config CAN_MCBA_USB + tristate "Microchip CAN BUS Analyzer interface" + ---help--- + This driver supports the CAN BUS Analyzer interface + from Microchip (http://www.microchip.com/development-tools/). + endmenu diff --git a/drivers/net/can/usb/Makefile b/drivers/net/can/usb/Makefile index a64cf983fb87..164453fd55d0 100644 --- a/drivers/net/can/usb/Makefile +++ b/drivers/net/can/usb/Makefile @@ -8,3 +8,4 @@ obj-$(CONFIG_CAN_GS_USB) += gs_usb.o obj-$(CONFIG_CAN_KVASER_USB) += kvaser_usb.o obj-$(CONFIG_CAN_PEAK_USB) += peak_usb/ obj-$(CONFIG_CAN_8DEV_USB) += usb_8dev.o +obj-$(CONFIG_CAN_MCBA_USB) += mcba_usb.o diff --git a/drivers/net/can/usb/mcba_usb.c b/drivers/net/can/usb/mcba_usb.c new file mode 100644 index 000000000000..7f0272558bef --- /dev/null +++ b/drivers/net/can/usb/mcba_usb.c @@ -0,0 +1,904 @@ +/* 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* 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 mcba_usb_free_ctx(struct mcba_usb_ctx *ctx) +{ + /* Increase number of free ctxs before freeing ctx */ + atomic_inc(&ctx->priv->free_ctx_cnt); + + ctx->ndx = MCBA_CTX_FREE; + + /* Wake up the queue once ctx is marked free */ + netif_wake_queue(ctx->priv->netdev); +} + +static void mcba_usb_write_bulk_callback(struct urb *urb) +{ + struct mcba_usb_ctx *ctx = urb->context; + struct net_device *netdev; + + WARN_ON(!ctx); + + netdev = ctx->priv->netdev; + + /* free up our allocated buffer */ + usb_free_coherent(urb->dev, urb->transfer_buffer_length, + urb->transfer_buffer, urb->transfer_dma); + + if (ctx->can) { + if (!netif_device_present(netdev)) + return; + + netdev->stats.tx_packets++; + netdev->stats.tx_bytes += ctx->dlc; + + can_led_event(netdev, CAN_LED_EVENT_TX); + can_get_echo_skb(netdev, ctx->ndx); + } + + if (urb->status) + netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status); + + /* Release the context */ + mcba_usb_free_ctx(ctx); +} + +/* Send data to device */ +static netdev_tx_t mcba_usb_xmit(struct mcba_priv *priv, + struct mcba_usb_msg *usb_msg, + struct mcba_usb_ctx *ctx) +{ + struct urb *urb; + u8 *buf; + int err; + + /* create a URB, and a buffer for it, and copy the data to the URB */ + urb = usb_alloc_urb(0, GFP_ATOMIC); + if (!urb) + return -ENOMEM; + + buf = usb_alloc_coherent(priv->udev, MCBA_USB_TX_BUFF_SIZE, GFP_ATOMIC, + &urb->transfer_dma); + if (!buf) { + err = -ENOMEM; + goto nomembuf; + } + + memcpy(buf, usb_msg, MCBA_USB_TX_BUFF_SIZE); + + usb_fill_bulk_urb(urb, priv->udev, + usb_sndbulkpipe(priv->udev, MCBA_USB_EP_OUT), buf, + MCBA_USB_TX_BUFF_SIZE, mcba_usb_write_bulk_callback, + ctx); + + urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; + usb_anchor_urb(urb, &priv->tx_submitted); + + err = usb_submit_urb(urb, GFP_ATOMIC); + if (unlikely(err)) + goto failed; + + /* Release our reference to this URB, the USB core will eventually free + * it entirely. + */ + usb_free_urb(urb); + + return 0; + +failed: + usb_unanchor_urb(urb); + usb_free_coherent(priv->udev, MCBA_USB_TX_BUFF_SIZE, buf, + urb->transfer_dma); + + if (err == -ENODEV) + netif_device_detach(priv->netdev); + else + netdev_warn(priv->netdev, "failed tx_urb %d\n", err); + +nomembuf: + usb_free_urb(urb); + + return err; +} + +/* Send data to device */ +static netdev_tx_t mcba_usb_start_xmit(struct sk_buff *skb, + struct net_device *netdev) +{ + struct mcba_priv *priv = netdev_priv(netdev); + struct can_frame *cf = (struct can_frame *)skb->data; + struct mcba_usb_ctx *ctx = NULL; + struct net_device_stats *stats = &priv->netdev->stats; + u16 sid; + int err; + struct mcba_usb_msg_can usb_msg = { + .cmd_id = MBCA_CMD_TRANSMIT_MESSAGE_EV + }; + + if (can_dropped_invalid_skb(netdev, skb)) + return NETDEV_TX_OK; + + ctx = mcba_usb_get_free_ctx(priv, cf); + if (!ctx) + return NETDEV_TX_BUSY; + + can_put_echo_skb(skb, priv->netdev, ctx->ndx); + + if (cf->can_id & CAN_EFF_FLAG) { + /* SIDH | SIDL | EIDH | EIDL + * 28 - 21 | 20 19 18 x x x 17 16 | 15 - 8 | 7 - 0 + */ + sid = MCBA_SIDL_EXID_MASK; + /* store 28-18 bits */ + sid |= (cf->can_id & 0x1ffc0000) >> 13; + /* store 17-16 bits */ + sid |= (cf->can_id & 0x30000) >> 16; + put_unaligned_be16(sid, &usb_msg.sid); + + /* store 15-0 bits */ + put_unaligned_be16(cf->can_id & 0xffff, &usb_msg.eid); + } else { + /* SIDH | SIDL + * 10 - 3 | 2 1 0 x x x x x + */ + put_unaligned_be16((cf->can_id & CAN_SFF_MASK) << 5, + &usb_msg.sid); + usb_msg.eid = 0; + } + + usb_msg.dlc = cf->can_dlc; + + memcpy(usb_msg.data, cf->data, usb_msg.dlc); + + if (cf->can_id & CAN_RTR_FLAG) + usb_msg.dlc |= MCBA_DLC_RTR_MASK; + + err = mcba_usb_xmit(priv, (struct mcba_usb_msg *)&usb_msg, ctx); + if (err) + goto xmit_failed; + + return NETDEV_TX_OK; + +xmit_failed: + can_free_echo_skb(priv->netdev, ctx->ndx); + mcba_usb_free_ctx(ctx); + dev_kfree_skb(skb); + stats->tx_dropped++; + + return NETDEV_TX_OK; +} + +/* Send cmd to device */ +static void mcba_usb_xmit_cmd(struct mcba_priv *priv, + struct mcba_usb_msg *usb_msg) +{ + struct mcba_usb_ctx *ctx = NULL; + int err; + + ctx = mcba_usb_get_free_ctx(priv, NULL); + if (!ctx) { + netdev_err(priv->netdev, + "Lack of free ctx. Sending (%d) cmd aborted", + usb_msg->cmd_id); + + return; + } + + err = mcba_usb_xmit(priv, usb_msg, ctx); + if (err) + netdev_err(priv->netdev, "Failed to send cmd (%d)", + usb_msg->cmd_id); +} + +static void mcba_usb_xmit_change_bitrate(struct mcba_priv *priv, u16 bitrate) +{ + struct mcba_usb_msg_change_bitrate usb_msg = { + .cmd_id = MBCA_CMD_CHANGE_BIT_RATE + }; + + put_unaligned_be16(bitrate, &usb_msg.bitrate); + + mcba_usb_xmit_cmd(priv, (struct mcba_usb_msg *)&usb_msg); +} + +static void mcba_usb_xmit_read_fw_ver(struct mcba_priv *priv, u8 pic) +{ + struct mcba_usb_msg_fw_ver usb_msg = { + .cmd_id = MBCA_CMD_READ_FW_VERSION, + .pic = pic + }; + + mcba_usb_xmit_cmd(priv, (struct mcba_usb_msg *)&usb_msg); +} + +static void mcba_usb_process_can(struct mcba_priv *priv, + struct mcba_usb_msg_can *msg) +{ + struct can_frame *cf; + struct sk_buff *skb; + struct net_device_stats *stats = &priv->netdev->stats; + u16 sid; + + skb = alloc_can_skb(priv->netdev, &cf); + if (!skb) + return; + + sid = get_unaligned_be16(&msg->sid); + + if (sid & MCBA_SIDL_EXID_MASK) { + /* SIDH | SIDL | EIDH | EIDL + * 28 - 21 | 20 19 18 x x x 17 16 | 15 - 8 | 7 - 0 + */ + cf->can_id = CAN_EFF_FLAG; + + /* store 28-18 bits */ + cf->can_id |= (sid & 0xffe0) << 13; + /* store 17-16 bits */ + cf->can_id |= (sid & 3) << 16; + /* store 15-0 bits */ + cf->can_id |= get_unaligned_be16(&msg->eid); + } else { + /* SIDH | SIDL + * 10 - 3 | 2 1 0 x x x x x + */ + cf->can_id = (sid & 0xffe0) >> 5; + } + + if (msg->dlc & MCBA_DLC_RTR_MASK) + cf->can_id |= CAN_RTR_FLAG; + + cf->can_dlc = get_can_dlc(msg->dlc & MCBA_DLC_MASK); + + memcpy(cf->data, msg->data, cf->can_dlc); + + stats->rx_packets++; + stats->rx_bytes += cf->can_dlc; + + can_led_event(priv->netdev, CAN_LED_EVENT_RX); + netif_rx(skb); +} + +static void mcba_usb_process_ka_usb(struct mcba_priv *priv, + struct mcba_usb_msg_ka_usb *msg) +{ + if (unlikely(priv->usb_ka_first_pass)) { + netdev_info(priv->netdev, "PIC USB version %hhu.%hhu\n", + msg->soft_ver_major, msg->soft_ver_minor); + + priv->usb_ka_first_pass = false; + } + + if (msg->termination_state) + priv->can.termination = MCBA_TERMINATION_ENABLED; + else + priv->can.termination = MCBA_TERMINATION_DISABLED; +} + +static u32 convert_can2host_bitrate(struct mcba_usb_msg_ka_can *msg) +{ + const u32 bitrate = get_unaligned_be16(&msg->can_bitrate); + + if ((bitrate == 33) || (bitrate == 83)) + return bitrate * 1000 + 333; + else + return bitrate * 1000; +} + +static void mcba_usb_process_ka_can(struct mcba_priv *priv, + struct mcba_usb_msg_ka_can *msg) +{ + if (unlikely(priv->can_ka_first_pass)) { + netdev_info(priv->netdev, "PIC CAN version %hhu.%hhu\n", + msg->soft_ver_major, msg->soft_ver_minor); + + priv->can_ka_first_pass = false; + } + + if (unlikely(priv->can_speed_check)) { + const u32 bitrate = convert_can2host_bitrate(msg); + + priv->can_speed_check = false; + + if (bitrate != priv->can.bittiming.bitrate) + netdev_err( + priv->netdev, + "Wrong bitrate reported by the device (%u). Expected %u", + bitrate, priv->can.bittiming.bitrate); + } + + priv->bec.txerr = msg->tx_err_cnt; + priv->bec.rxerr = msg->rx_err_cnt; + + if (msg->tx_bus_off) + priv->can.state = CAN_STATE_BUS_OFF; + + else if ((priv->bec.txerr > MCBA_CAN_STATE_ERR_PSV_TH) || + (priv->bec.rxerr > MCBA_CAN_STATE_ERR_PSV_TH)) + priv->can.state = CAN_STATE_ERROR_PASSIVE; + + else if ((priv->bec.txerr > MCBA_CAN_STATE_WRN_TH) || + (priv->bec.rxerr > MCBA_CAN_STATE_WRN_TH)) + priv->can.state = CAN_STATE_ERROR_WARNING; +} + +static void mcba_usb_process_rx(struct mcba_priv *priv, + struct mcba_usb_msg *msg) +{ + switch (msg->cmd_id) { + case MBCA_CMD_I_AM_ALIVE_FROM_CAN: + mcba_usb_process_ka_can(priv, + (struct mcba_usb_msg_ka_can *)msg); + break; + + case MBCA_CMD_I_AM_ALIVE_FROM_USB: + mcba_usb_process_ka_usb(priv, + (struct mcba_usb_msg_ka_usb *)msg); + break; + + case MBCA_CMD_RECEIVE_MESSAGE: + mcba_usb_process_can(priv, (struct mcba_usb_msg_can *)msg); + break; + + case MBCA_CMD_NOTHING_TO_SEND: + /* Side effect of communication between PIC_USB and PIC_CAN. + * PIC_CAN is telling us that it has nothing to send + */ + break; + + case MBCA_CMD_TRANSMIT_MESSAGE_RSP: + /* Transmission response from the device containing timestamp */ + break; + + default: + netdev_warn(priv->netdev, "Unsupported msg (0x%hhX)", + msg->cmd_id); + break; + } +} + +/* Callback for reading data from device + * + * Check urb status, call read function and resubmit urb read operation. + */ +static void mcba_usb_read_bulk_callback(struct urb *urb) +{ + struct mcba_priv *priv = urb->context; + struct net_device *netdev; + int retval; + int pos = 0; + + netdev = priv->netdev; + + if (!netif_device_present(netdev)) + return; + + switch (urb->status) { + case 0: /* success */ + break; + + case -ENOENT: + case -ESHUTDOWN: + return; + + default: + netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status); + + goto resubmit_urb; + } + + while (pos < urb->actual_length) { + struct mcba_usb_msg *msg; + + if (pos + sizeof(struct mcba_usb_msg) > urb->actual_length) { + netdev_err(priv->netdev, "format error\n"); + break; + } + + msg = (struct mcba_usb_msg *)(urb->transfer_buffer + pos); + mcba_usb_process_rx(priv, msg); + + pos += sizeof(struct mcba_usb_msg); + } + +resubmit_urb: + + usb_fill_bulk_urb(urb, priv->udev, + usb_rcvbulkpipe(priv->udev, MCBA_USB_EP_OUT), + urb->transfer_buffer, MCBA_USB_RX_BUFF_SIZE, + mcba_usb_read_bulk_callback, priv); + + retval = usb_submit_urb(urb, GFP_ATOMIC); + + if (retval == -ENODEV) + netif_device_detach(netdev); + else if (retval) + netdev_err(netdev, "failed resubmitting read bulk urb: %d\n", + retval); +} + +/* Start USB device */ +static int mcba_usb_start(struct mcba_priv *priv) +{ + struct net_device *netdev = priv->netdev; + int err, i; + + mcba_init_ctx(priv); + + for (i = 0; i < MCBA_MAX_RX_URBS; i++) { + struct urb *urb = NULL; + u8 *buf; + + /* create a URB, and a buffer for it */ + urb = usb_alloc_urb(0, GFP_KERNEL); + if (!urb) { + err = -ENOMEM; + break; + } + + buf = usb_alloc_coherent(priv->udev, MCBA_USB_RX_BUFF_SIZE, + GFP_KERNEL, &urb->transfer_dma); + if (!buf) { + netdev_err(netdev, "No memory left for USB buffer\n"); + usb_free_urb(urb); + err = -ENOMEM; + break; + } + + usb_fill_bulk_urb(urb, priv->udev, + usb_rcvbulkpipe(priv->udev, MCBA_USB_EP_IN), + buf, MCBA_USB_RX_BUFF_SIZE, + mcba_usb_read_bulk_callback, priv); + urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; + usb_anchor_urb(urb, &priv->rx_submitted); + + err = usb_submit_urb(urb, GFP_KERNEL); + if (err) { + usb_unanchor_urb(urb); + usb_free_coherent(priv->udev, MCBA_USB_RX_BUFF_SIZE, + buf, urb->transfer_dma); + usb_free_urb(urb); + break; + } + + /* Drop reference, USB core will take care of freeing it */ + usb_free_urb(urb); + } + + /* Did we submit any URBs */ + if (i == 0) { + netdev_warn(netdev, "couldn't setup read URBs\n"); + return err; + } + + /* Warn if we've couldn't transmit all the URBs */ + if (i < MCBA_MAX_RX_URBS) + netdev_warn(netdev, "rx performance may be slow\n"); + + mcba_usb_xmit_read_fw_ver(priv, MCBA_VER_REQ_USB); + mcba_usb_xmit_read_fw_ver(priv, MCBA_VER_REQ_CAN); + + return err; +} + +/* Open USB device */ +static int mcba_usb_open(struct net_device *netdev) +{ + struct mcba_priv *priv = netdev_priv(netdev); + int err; + + /* common open */ + err = open_candev(netdev); + if (err) + return err; + + priv->can_speed_check = true; + priv->can.state = CAN_STATE_ERROR_ACTIVE; + + can_led_event(netdev, CAN_LED_EVENT_OPEN); + netif_start_queue(netdev); + + return 0; +} + +static void mcba_urb_unlink(struct mcba_priv *priv) +{ + usb_kill_anchored_urbs(&priv->rx_submitted); + usb_kill_anchored_urbs(&priv->tx_submitted); +} + +/* Close USB device */ +static int mcba_usb_close(struct net_device *netdev) +{ + struct mcba_priv *priv = netdev_priv(netdev); + + priv->can.state = CAN_STATE_STOPPED; + + netif_stop_queue(netdev); + + /* Stop polling */ + mcba_urb_unlink(priv); + + close_candev(netdev); + can_led_event(netdev, CAN_LED_EVENT_STOP); + + return 0; +} + +/* Set network device mode + * + * Maybe we should leave this function empty, because the device + * set mode variable with open command. + */ +static int mcba_net_set_mode(struct net_device *netdev, enum can_mode mode) +{ + return 0; +} + +static int mcba_net_get_berr_counter(const struct net_device *netdev, + struct can_berr_counter *bec) +{ + struct mcba_priv *priv = netdev_priv(netdev); + + bec->txerr = priv->bec.txerr; + bec->rxerr = priv->bec.rxerr; + + return 0; +} + +static const struct net_device_ops mcba_netdev_ops = { + .ndo_open = mcba_usb_open, + .ndo_stop = mcba_usb_close, + .ndo_start_xmit = mcba_usb_start_xmit, +}; + +/* Microchip CANBUS has hardcoded bittiming values by default. + * This function sends request via USB to change the speed and align bittiming + * values for presentation purposes only + */ +static int mcba_net_set_bittiming(struct net_device *netdev) +{ + struct mcba_priv *priv = netdev_priv(netdev); + const u16 bitrate_kbps = priv->can.bittiming.bitrate / 1000; + + mcba_usb_xmit_change_bitrate(priv, bitrate_kbps); + + return 0; +} + +static int mcba_set_termination(struct net_device *netdev, u16 term) +{ + struct mcba_priv *priv = netdev_priv(netdev); + struct mcba_usb_msg_termination usb_msg = { + .cmd_id = MBCA_CMD_SETUP_TERMINATION_RESISTANCE + }; + + if (term == MCBA_TERMINATION_ENABLED) + usb_msg.termination = 1; + else + usb_msg.termination = 0; + + mcba_usb_xmit_cmd(priv, (struct mcba_usb_msg *)&usb_msg); + + return 0; +} + +static int mcba_usb_probe(struct usb_interface *intf, + const struct usb_device_id *id) +{ + struct net_device *netdev; + struct mcba_priv *priv; + int err = -ENOMEM; + struct usb_device *usbdev = interface_to_usbdev(intf); + + netdev = alloc_candev(sizeof(struct mcba_priv), MCBA_MAX_TX_URBS); + if (!netdev) { + dev_err(&intf->dev, "Couldn't alloc candev\n"); + return -ENOMEM; + } + + priv = netdev_priv(netdev); + + priv->udev = usbdev; + priv->netdev = netdev; + priv->usb_ka_first_pass = true; + priv->can_ka_first_pass = true; + priv->can_speed_check = false; + + init_usb_anchor(&priv->rx_submitted); + init_usb_anchor(&priv->tx_submitted); + + usb_set_intfdata(intf, priv); + + /* Init CAN device */ + priv->can.state = CAN_STATE_STOPPED; + priv->can.termination_const = mcba_termination; + priv->can.termination_const_cnt = ARRAY_SIZE(mcba_termination); + priv->can.bitrate_const = mcba_bitrate; + priv->can.bitrate_const_cnt = ARRAY_SIZE(mcba_bitrate); + + priv->can.do_set_termination = mcba_set_termination; + priv->can.do_set_mode = mcba_net_set_mode; + priv->can.do_get_berr_counter = mcba_net_get_berr_counter; + priv->can.do_set_bittiming = mcba_net_set_bittiming; + + netdev->netdev_ops = &mcba_netdev_ops; + + netdev->flags |= IFF_ECHO; /* we support local echo */ + + SET_NETDEV_DEV(netdev, &intf->dev); + + err = register_candev(netdev); + if (err) { + netdev_err(netdev, "couldn't register CAN device: %d\n", err); + + goto cleanup_free_candev; + } + + devm_can_led_init(netdev); + + /* Start USB dev only if we have successfully registered CAN device */ + err = mcba_usb_start(priv); + if (err) { + if (err == -ENODEV) + netif_device_detach(priv->netdev); + + netdev_warn(netdev, "couldn't start device: %d\n", err); + + goto cleanup_unregister_candev; + } + + dev_info(&intf->dev, "Microchip CAN BUS analizer connected\n"); + + return 0; + +cleanup_unregister_candev: + unregister_candev(priv->netdev); + +cleanup_free_candev: + free_candev(netdev); + + return err; +} + +/* Called by the usb core when driver is unloaded or device is removed */ +static void mcba_usb_disconnect(struct usb_interface *intf) +{ + struct mcba_priv *priv = usb_get_intfdata(intf); + + usb_set_intfdata(intf, NULL); + + netdev_info(priv->netdev, "device disconnected\n"); + + unregister_candev(priv->netdev); + free_candev(priv->netdev); + + mcba_urb_unlink(priv); +} + +static struct usb_driver mcba_usb_driver = { + .name = MCBA_MODULE_NAME, + .probe = mcba_usb_probe, + .disconnect = mcba_usb_disconnect, + .id_table = mcba_usb_table, +}; + +module_usb_driver(mcba_usb_driver); + +MODULE_AUTHOR("Remigiusz Kołłątaj "); +MODULE_DESCRIPTION("SocketCAN driver for Microchip CAN BUS Analyzer Tool"); +MODULE_LICENSE("GPL v2"); -- GitLab