diff options
Diffstat (limited to 'drivers/net/can/usb/peak_usb/pcan_usb.c')
| -rw-r--r-- | drivers/net/can/usb/peak_usb/pcan_usb.c | 1031 |
1 files changed, 1031 insertions, 0 deletions
diff --git a/drivers/net/can/usb/peak_usb/pcan_usb.c b/drivers/net/can/usb/peak_usb/pcan_usb.c new file mode 100644 index 000000000..ce2d0761c --- /dev/null +++ b/drivers/net/can/usb/peak_usb/pcan_usb.c @@ -0,0 +1,1031 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * CAN driver for PEAK System PCAN-USB adapter + * Derived from the PCAN project file driver/src/pcan_usb.c + * + * Copyright (C) 2003-2010 PEAK System-Technik GmbH + * Copyright (C) 2011-2012 Stephane Grosjean <s.grosjean@peak-system.com> + * + * Many thanks to Klaus Hitschler <klaus.hitschler@gmx.de> + */ +#include <linux/netdevice.h> +#include <linux/usb.h> +#include <linux/module.h> + +#include <linux/can.h> +#include <linux/can/dev.h> +#include <linux/can/error.h> + +#include "pcan_usb_core.h" + +MODULE_SUPPORTED_DEVICE("PEAK-System PCAN-USB adapter"); + +/* PCAN-USB Endpoints */ +#define PCAN_USB_EP_CMDOUT 1 +#define PCAN_USB_EP_CMDIN (PCAN_USB_EP_CMDOUT | USB_DIR_IN) +#define PCAN_USB_EP_MSGOUT 2 +#define PCAN_USB_EP_MSGIN (PCAN_USB_EP_MSGOUT | USB_DIR_IN) + +/* PCAN-USB command struct */ +#define PCAN_USB_CMD_FUNC 0 +#define PCAN_USB_CMD_NUM 1 +#define PCAN_USB_CMD_ARGS 2 +#define PCAN_USB_CMD_ARGS_LEN 14 +#define PCAN_USB_CMD_LEN (PCAN_USB_CMD_ARGS + \ + PCAN_USB_CMD_ARGS_LEN) + +/* PCAN-USB commands */ +#define PCAN_USB_CMD_BITRATE 1 +#define PCAN_USB_CMD_SET_BUS 3 +#define PCAN_USB_CMD_DEVID 4 +#define PCAN_USB_CMD_SN 6 +#define PCAN_USB_CMD_REGISTER 9 +#define PCAN_USB_CMD_EXT_VCC 10 +#define PCAN_USB_CMD_ERR_FR 11 + +/* PCAN_USB_CMD_SET_BUS number arg */ +#define PCAN_USB_BUS_XCVER 2 +#define PCAN_USB_BUS_SILENT_MODE 3 + +/* PCAN_USB_CMD_xxx functions */ +#define PCAN_USB_GET 1 +#define PCAN_USB_SET 2 + +/* PCAN-USB command timeout (ms.) */ +#define PCAN_USB_COMMAND_TIMEOUT 1000 + +/* PCAN-USB startup timeout (ms.) */ +#define PCAN_USB_STARTUP_TIMEOUT 10 + +/* PCAN-USB rx/tx buffers size */ +#define PCAN_USB_RX_BUFFER_SIZE 64 +#define PCAN_USB_TX_BUFFER_SIZE 64 + +#define PCAN_USB_MSG_HEADER_LEN 2 + +/* PCAN-USB adapter internal clock (MHz) */ +#define PCAN_USB_CRYSTAL_HZ 16000000 + +/* PCAN-USB USB message record status/len field */ +#define PCAN_USB_STATUSLEN_TIMESTAMP (1 << 7) +#define PCAN_USB_STATUSLEN_INTERNAL (1 << 6) +#define PCAN_USB_STATUSLEN_EXT_ID (1 << 5) +#define PCAN_USB_STATUSLEN_RTR (1 << 4) +#define PCAN_USB_STATUSLEN_DLC (0xf) + +/* PCAN-USB error flags */ +#define PCAN_USB_ERROR_TXFULL 0x01 +#define PCAN_USB_ERROR_RXQOVR 0x02 +#define PCAN_USB_ERROR_BUS_LIGHT 0x04 +#define PCAN_USB_ERROR_BUS_HEAVY 0x08 +#define PCAN_USB_ERROR_BUS_OFF 0x10 +#define PCAN_USB_ERROR_RXQEMPTY 0x20 +#define PCAN_USB_ERROR_QOVR 0x40 +#define PCAN_USB_ERROR_TXQFULL 0x80 + +#define PCAN_USB_ERROR_BUS (PCAN_USB_ERROR_BUS_LIGHT | \ + PCAN_USB_ERROR_BUS_HEAVY | \ + PCAN_USB_ERROR_BUS_OFF) + +/* SJA1000 modes */ +#define SJA1000_MODE_NORMAL 0x00 +#define SJA1000_MODE_INIT 0x01 + +/* + * tick duration = 42.666 us => + * (tick_number * 44739243) >> 20 ~ (tick_number * 42666) / 1000 + * accuracy = 10^-7 + */ +#define PCAN_USB_TS_DIV_SHIFTER 20 +#define PCAN_USB_TS_US_PER_TICK 44739243 + +/* PCAN-USB messages record types */ +#define PCAN_USB_REC_ERROR 1 +#define PCAN_USB_REC_ANALOG 2 +#define PCAN_USB_REC_BUSLOAD 3 +#define PCAN_USB_REC_TS 4 +#define PCAN_USB_REC_BUSEVT 5 + +/* CAN bus events notifications selection mask */ +#define PCAN_USB_ERR_RXERR 0x02 /* ask for rxerr counter */ +#define PCAN_USB_ERR_TXERR 0x04 /* ask for txerr counter */ + +/* This mask generates an usb packet each time the state of the bus changes. + * In other words, its interest is to know which side among rx and tx is + * responsible of the change of the bus state. + */ +#define PCAN_USB_BERR_MASK (PCAN_USB_ERR_RXERR | PCAN_USB_ERR_TXERR) + +/* identify bus event packets with rx/tx error counters */ +#define PCAN_USB_ERR_CNT_DEC 0x00 /* counters are decreasing */ +#define PCAN_USB_ERR_CNT_INC 0x80 /* counters are increasing */ + +/* private to PCAN-USB adapter */ +struct pcan_usb { + struct peak_usb_device dev; + struct peak_time_ref time_ref; + struct timer_list restart_timer; + struct can_berr_counter bec; +}; + +/* incoming message context for decoding */ +struct pcan_usb_msg_context { + u16 ts16; + u8 prev_ts8; + u8 *ptr; + u8 *end; + u8 rec_cnt; + u8 rec_idx; + u8 rec_ts_idx; + struct net_device *netdev; + struct pcan_usb *pdev; +}; + +/* + * send a command + */ +static int pcan_usb_send_cmd(struct peak_usb_device *dev, u8 f, u8 n, u8 *p) +{ + int err; + int actual_length; + + /* usb device unregistered? */ + if (!(dev->state & PCAN_USB_STATE_CONNECTED)) + return 0; + + dev->cmd_buf[PCAN_USB_CMD_FUNC] = f; + dev->cmd_buf[PCAN_USB_CMD_NUM] = n; + + if (p) + memcpy(dev->cmd_buf + PCAN_USB_CMD_ARGS, + p, PCAN_USB_CMD_ARGS_LEN); + + err = usb_bulk_msg(dev->udev, + usb_sndbulkpipe(dev->udev, PCAN_USB_EP_CMDOUT), + dev->cmd_buf, PCAN_USB_CMD_LEN, &actual_length, + PCAN_USB_COMMAND_TIMEOUT); + if (err) + netdev_err(dev->netdev, + "sending cmd f=0x%x n=0x%x failure: %d\n", + f, n, err); + return err; +} + +/* + * send a command then wait for its response + */ +static int pcan_usb_wait_rsp(struct peak_usb_device *dev, u8 f, u8 n, u8 *p) +{ + int err; + int actual_length; + + /* usb device unregistered? */ + if (!(dev->state & PCAN_USB_STATE_CONNECTED)) + return 0; + + /* first, send command */ + err = pcan_usb_send_cmd(dev, f, n, NULL); + if (err) + return err; + + err = usb_bulk_msg(dev->udev, + usb_rcvbulkpipe(dev->udev, PCAN_USB_EP_CMDIN), + dev->cmd_buf, PCAN_USB_CMD_LEN, &actual_length, + PCAN_USB_COMMAND_TIMEOUT); + if (err) + netdev_err(dev->netdev, + "waiting rsp f=0x%x n=0x%x failure: %d\n", f, n, err); + else if (p) + memcpy(p, dev->cmd_buf + PCAN_USB_CMD_ARGS, + PCAN_USB_CMD_ARGS_LEN); + + return err; +} + +static int pcan_usb_set_sja1000(struct peak_usb_device *dev, u8 mode) +{ + u8 args[PCAN_USB_CMD_ARGS_LEN] = { + [1] = mode, + }; + + return pcan_usb_send_cmd(dev, PCAN_USB_CMD_REGISTER, PCAN_USB_SET, + args); +} + +static int pcan_usb_set_bus(struct peak_usb_device *dev, u8 onoff) +{ + u8 args[PCAN_USB_CMD_ARGS_LEN] = { + [0] = !!onoff, + }; + + return pcan_usb_send_cmd(dev, PCAN_USB_CMD_SET_BUS, PCAN_USB_BUS_XCVER, + args); +} + +static int pcan_usb_set_silent(struct peak_usb_device *dev, u8 onoff) +{ + u8 args[PCAN_USB_CMD_ARGS_LEN] = { + [0] = !!onoff, + }; + + return pcan_usb_send_cmd(dev, PCAN_USB_CMD_SET_BUS, + PCAN_USB_BUS_SILENT_MODE, args); +} + +/* send the cmd to be notified from bus errors */ +static int pcan_usb_set_err_frame(struct peak_usb_device *dev, u8 err_mask) +{ + u8 args[PCAN_USB_CMD_ARGS_LEN] = { + [0] = err_mask, + }; + + return pcan_usb_send_cmd(dev, PCAN_USB_CMD_ERR_FR, PCAN_USB_SET, args); +} + +static int pcan_usb_set_ext_vcc(struct peak_usb_device *dev, u8 onoff) +{ + u8 args[PCAN_USB_CMD_ARGS_LEN] = { + [0] = !!onoff, + }; + + return pcan_usb_send_cmd(dev, PCAN_USB_CMD_EXT_VCC, PCAN_USB_SET, args); +} + +/* + * set bittiming value to can + */ +static int pcan_usb_set_bittiming(struct peak_usb_device *dev, + struct can_bittiming *bt) +{ + u8 args[PCAN_USB_CMD_ARGS_LEN]; + u8 btr0, btr1; + + btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); + btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | + (((bt->phase_seg2 - 1) & 0x7) << 4); + if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) + btr1 |= 0x80; + + netdev_info(dev->netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", + btr0, btr1); + + args[0] = btr1; + args[1] = btr0; + + return pcan_usb_send_cmd(dev, PCAN_USB_CMD_BITRATE, PCAN_USB_SET, args); +} + +/* + * init/reset can + */ +static int pcan_usb_write_mode(struct peak_usb_device *dev, u8 onoff) +{ + int err; + + err = pcan_usb_set_bus(dev, onoff); + if (err) + return err; + + if (!onoff) { + err = pcan_usb_set_sja1000(dev, SJA1000_MODE_INIT); + } else { + /* the PCAN-USB needs time to init */ + set_current_state(TASK_INTERRUPTIBLE); + schedule_timeout(msecs_to_jiffies(PCAN_USB_STARTUP_TIMEOUT)); + } + + return err; +} + +/* + * handle end of waiting for the device to reset + */ +static void pcan_usb_restart(struct timer_list *t) +{ + struct pcan_usb *pdev = from_timer(pdev, t, restart_timer); + struct peak_usb_device *dev = &pdev->dev; + + /* notify candev and netdev */ + peak_usb_restart_complete(dev); +} + +/* + * handle the submission of the restart urb + */ +static void pcan_usb_restart_pending(struct urb *urb) +{ + struct pcan_usb *pdev = urb->context; + + /* the PCAN-USB needs time to restart */ + mod_timer(&pdev->restart_timer, + jiffies + msecs_to_jiffies(PCAN_USB_STARTUP_TIMEOUT)); + + /* can delete usb resources */ + peak_usb_async_complete(urb); +} + +/* + * handle asynchronous restart + */ +static int pcan_usb_restart_async(struct peak_usb_device *dev, struct urb *urb, + u8 *buf) +{ + struct pcan_usb *pdev = container_of(dev, struct pcan_usb, dev); + + if (timer_pending(&pdev->restart_timer)) + return -EBUSY; + + /* set bus on */ + buf[PCAN_USB_CMD_FUNC] = 3; + buf[PCAN_USB_CMD_NUM] = 2; + buf[PCAN_USB_CMD_ARGS] = 1; + + usb_fill_bulk_urb(urb, dev->udev, + usb_sndbulkpipe(dev->udev, PCAN_USB_EP_CMDOUT), + buf, PCAN_USB_CMD_LEN, + pcan_usb_restart_pending, pdev); + + return usb_submit_urb(urb, GFP_ATOMIC); +} + +/* + * read serial number from device + */ +static int pcan_usb_get_serial(struct peak_usb_device *dev, u32 *serial_number) +{ + u8 args[PCAN_USB_CMD_ARGS_LEN]; + int err; + + err = pcan_usb_wait_rsp(dev, PCAN_USB_CMD_SN, PCAN_USB_GET, args); + if (err) { + netdev_err(dev->netdev, "getting serial failure: %d\n", err); + } else if (serial_number) { + __le32 tmp32; + + memcpy(&tmp32, args, 4); + *serial_number = le32_to_cpu(tmp32); + } + + return err; +} + +/* + * read device id from device + */ +static int pcan_usb_get_device_id(struct peak_usb_device *dev, u32 *device_id) +{ + u8 args[PCAN_USB_CMD_ARGS_LEN]; + int err; + + err = pcan_usb_wait_rsp(dev, PCAN_USB_CMD_DEVID, PCAN_USB_GET, args); + if (err) + netdev_err(dev->netdev, "getting device id failure: %d\n", err); + else if (device_id) + *device_id = args[0]; + + return err; +} + +/* + * update current time ref with received timestamp + */ +static int pcan_usb_update_ts(struct pcan_usb_msg_context *mc) +{ + __le16 tmp16; + + if ((mc->ptr+2) > mc->end) + return -EINVAL; + + memcpy(&tmp16, mc->ptr, 2); + + mc->ts16 = le16_to_cpu(tmp16); + + if (mc->rec_idx > 0) + peak_usb_update_ts_now(&mc->pdev->time_ref, mc->ts16); + else + peak_usb_set_ts_now(&mc->pdev->time_ref, mc->ts16); + + return 0; +} + +/* + * decode received timestamp + */ +static int pcan_usb_decode_ts(struct pcan_usb_msg_context *mc, u8 first_packet) +{ + /* only 1st packet supplies a word timestamp */ + if (first_packet) { + __le16 tmp16; + + if ((mc->ptr + 2) > mc->end) + return -EINVAL; + + memcpy(&tmp16, mc->ptr, 2); + mc->ptr += 2; + + mc->ts16 = le16_to_cpu(tmp16); + mc->prev_ts8 = mc->ts16 & 0x00ff; + } else { + u8 ts8; + + if ((mc->ptr + 1) > mc->end) + return -EINVAL; + + ts8 = *mc->ptr++; + + if (ts8 < mc->prev_ts8) + mc->ts16 += 0x100; + + mc->ts16 &= 0xff00; + mc->ts16 |= ts8; + mc->prev_ts8 = ts8; + } + + return 0; +} + +static int pcan_usb_decode_error(struct pcan_usb_msg_context *mc, u8 n, + u8 status_len) +{ + struct sk_buff *skb; + struct can_frame *cf; + enum can_state new_state; + + /* ignore this error until 1st ts received */ + if (n == PCAN_USB_ERROR_QOVR) + if (!mc->pdev->time_ref.tick_count) + return 0; + + new_state = mc->pdev->dev.can.state; + + switch (mc->pdev->dev.can.state) { + case CAN_STATE_ERROR_ACTIVE: + if (n & PCAN_USB_ERROR_BUS_LIGHT) { + new_state = CAN_STATE_ERROR_WARNING; + break; + } + fallthrough; + + case CAN_STATE_ERROR_WARNING: + if (n & PCAN_USB_ERROR_BUS_HEAVY) { + new_state = CAN_STATE_ERROR_PASSIVE; + break; + } + if (n & PCAN_USB_ERROR_BUS_OFF) { + new_state = CAN_STATE_BUS_OFF; + break; + } + if (n & ~PCAN_USB_ERROR_BUS) { + /* + * trick to bypass next comparison and process other + * errors + */ + new_state = CAN_STATE_MAX; + break; + } + if ((n & PCAN_USB_ERROR_BUS_LIGHT) == 0) { + /* no error (back to active state) */ + new_state = CAN_STATE_ERROR_ACTIVE; + break; + } + break; + + case CAN_STATE_ERROR_PASSIVE: + if (n & PCAN_USB_ERROR_BUS_OFF) { + new_state = CAN_STATE_BUS_OFF; + break; + } + if (n & PCAN_USB_ERROR_BUS_LIGHT) { + new_state = CAN_STATE_ERROR_WARNING; + break; + } + if (n & ~PCAN_USB_ERROR_BUS) { + /* + * trick to bypass next comparison and process other + * errors + */ + new_state = CAN_STATE_MAX; + break; + } + + if ((n & PCAN_USB_ERROR_BUS_HEAVY) == 0) { + /* no error (back to warning state) */ + new_state = CAN_STATE_ERROR_WARNING; + break; + } + break; + + default: + /* do nothing waiting for restart */ + return 0; + } + + /* donot post any error if current state didn't change */ + if (mc->pdev->dev.can.state == new_state) + return 0; + + /* allocate an skb to store the error frame */ + skb = alloc_can_err_skb(mc->netdev, &cf); + if (!skb) + return -ENOMEM; + + switch (new_state) { + case CAN_STATE_BUS_OFF: + cf->can_id |= CAN_ERR_BUSOFF; + mc->pdev->dev.can.can_stats.bus_off++; + can_bus_off(mc->netdev); + break; + + case CAN_STATE_ERROR_PASSIVE: + cf->can_id |= CAN_ERR_CRTL; + cf->data[1] = (mc->pdev->bec.txerr > mc->pdev->bec.rxerr) ? + CAN_ERR_CRTL_TX_PASSIVE : + CAN_ERR_CRTL_RX_PASSIVE; + cf->data[6] = mc->pdev->bec.txerr; + cf->data[7] = mc->pdev->bec.rxerr; + + mc->pdev->dev.can.can_stats.error_passive++; + break; + + case CAN_STATE_ERROR_WARNING: + cf->can_id |= CAN_ERR_CRTL; + cf->data[1] = (mc->pdev->bec.txerr > mc->pdev->bec.rxerr) ? + CAN_ERR_CRTL_TX_WARNING : + CAN_ERR_CRTL_RX_WARNING; + cf->data[6] = mc->pdev->bec.txerr; + cf->data[7] = mc->pdev->bec.rxerr; + + mc->pdev->dev.can.can_stats.error_warning++; + break; + + case CAN_STATE_ERROR_ACTIVE: + cf->can_id |= CAN_ERR_CRTL; + cf->data[1] = CAN_ERR_CRTL_ACTIVE; + + /* sync local copies of rxerr/txerr counters */ + mc->pdev->bec.txerr = 0; + mc->pdev->bec.rxerr = 0; + break; + + default: + /* CAN_STATE_MAX (trick to handle other errors) */ + if (n & PCAN_USB_ERROR_TXQFULL) + netdev_dbg(mc->netdev, "device Tx queue full)\n"); + + if (n & PCAN_USB_ERROR_RXQOVR) { + netdev_dbg(mc->netdev, "data overrun interrupt\n"); + cf->can_id |= CAN_ERR_CRTL; + cf->data[1] |= CAN_ERR_CRTL_RX_OVERFLOW; + mc->netdev->stats.rx_over_errors++; + mc->netdev->stats.rx_errors++; + } + + cf->data[6] = mc->pdev->bec.txerr; + cf->data[7] = mc->pdev->bec.rxerr; + + new_state = mc->pdev->dev.can.state; + break; + } + + mc->pdev->dev.can.state = new_state; + + if (status_len & PCAN_USB_STATUSLEN_TIMESTAMP) { + struct skb_shared_hwtstamps *hwts = skb_hwtstamps(skb); + + peak_usb_get_ts_time(&mc->pdev->time_ref, mc->ts16, + &hwts->hwtstamp); + } + + mc->netdev->stats.rx_packets++; + mc->netdev->stats.rx_bytes += cf->can_dlc; + netif_rx(skb); + + return 0; +} + +/* decode bus event usb packet: first byte contains rxerr while 2nd one contains + * txerr. + */ +static int pcan_usb_handle_bus_evt(struct pcan_usb_msg_context *mc, u8 ir) +{ + struct pcan_usb *pdev = mc->pdev; + + /* acccording to the content of the packet */ + switch (ir) { + case PCAN_USB_ERR_CNT_DEC: + case PCAN_USB_ERR_CNT_INC: + + /* save rx/tx error counters from in the device context */ + pdev->bec.rxerr = mc->ptr[1]; + pdev->bec.txerr = mc->ptr[2]; + break; + + default: + /* reserved */ + break; + } + + return 0; +} + +/* + * decode non-data usb message + */ +static int pcan_usb_decode_status(struct pcan_usb_msg_context *mc, + u8 status_len) +{ + u8 rec_len = status_len & PCAN_USB_STATUSLEN_DLC; + u8 f, n; + int err; + + /* check whether function and number can be read */ + if ((mc->ptr + 2) > mc->end) + return -EINVAL; + + f = mc->ptr[PCAN_USB_CMD_FUNC]; + n = mc->ptr[PCAN_USB_CMD_NUM]; + mc->ptr += PCAN_USB_CMD_ARGS; + + if (status_len & PCAN_USB_STATUSLEN_TIMESTAMP) { + int err = pcan_usb_decode_ts(mc, !mc->rec_ts_idx); + + if (err) + return err; + + /* Next packet in the buffer will have a timestamp on a single + * byte + */ + mc->rec_ts_idx++; + } + + switch (f) { + case PCAN_USB_REC_ERROR: + err = pcan_usb_decode_error(mc, n, status_len); + if (err) + return err; + break; + + case PCAN_USB_REC_ANALOG: + /* analog values (ignored) */ + rec_len = 2; + break; + + case PCAN_USB_REC_BUSLOAD: + /* bus load (ignored) */ + rec_len = 1; + break; + + case PCAN_USB_REC_TS: + /* only timestamp */ + if (pcan_usb_update_ts(mc)) + return -EINVAL; + break; + + case PCAN_USB_REC_BUSEVT: + /* bus event notifications (get rxerr/txerr) */ + err = pcan_usb_handle_bus_evt(mc, n); + if (err) + return err; + break; + default: + netdev_err(mc->netdev, "unexpected function %u\n", f); + break; + } + + if ((mc->ptr + rec_len) > mc->end) + return -EINVAL; + + mc->ptr += rec_len; + + return 0; +} + +/* + * decode data usb message + */ +static int pcan_usb_decode_data(struct pcan_usb_msg_context *mc, u8 status_len) +{ + u8 rec_len = status_len & PCAN_USB_STATUSLEN_DLC; + struct sk_buff *skb; + struct can_frame *cf; + struct skb_shared_hwtstamps *hwts; + + skb = alloc_can_skb(mc->netdev, &cf); + if (!skb) + return -ENOMEM; + + if (status_len & PCAN_USB_STATUSLEN_EXT_ID) { + __le32 tmp32; + + if ((mc->ptr + 4) > mc->end) + goto decode_failed; + + memcpy(&tmp32, mc->ptr, 4); + mc->ptr += 4; + + cf->can_id = (le32_to_cpu(tmp32) >> 3) | CAN_EFF_FLAG; + } else { + __le16 tmp16; + + if ((mc->ptr + 2) > mc->end) + goto decode_failed; + + memcpy(&tmp16, mc->ptr, 2); + mc->ptr += 2; + + cf->can_id = le16_to_cpu(tmp16) >> 5; + } + + cf->can_dlc = get_can_dlc(rec_len); + + /* Only first packet timestamp is a word */ + if (pcan_usb_decode_ts(mc, !mc->rec_ts_idx)) + goto decode_failed; + + /* Next packet in the buffer will have a timestamp on a single byte */ + mc->rec_ts_idx++; + + /* read data */ + memset(cf->data, 0x0, sizeof(cf->data)); + if (status_len & PCAN_USB_STATUSLEN_RTR) { + cf->can_id |= CAN_RTR_FLAG; + } else { + if ((mc->ptr + rec_len) > mc->end) + goto decode_failed; + + memcpy(cf->data, mc->ptr, cf->can_dlc); + mc->ptr += rec_len; + } + + /* convert timestamp into kernel time */ + hwts = skb_hwtstamps(skb); + peak_usb_get_ts_time(&mc->pdev->time_ref, mc->ts16, &hwts->hwtstamp); + + /* update statistics */ + mc->netdev->stats.rx_packets++; + mc->netdev->stats.rx_bytes += cf->can_dlc; + /* push the skb */ + netif_rx(skb); + + return 0; + +decode_failed: + dev_kfree_skb(skb); + return -EINVAL; +} + +/* + * process incoming message + */ +static int pcan_usb_decode_msg(struct peak_usb_device *dev, u8 *ibuf, u32 lbuf) +{ + struct pcan_usb_msg_context mc = { + .rec_cnt = ibuf[1], + .ptr = ibuf + PCAN_USB_MSG_HEADER_LEN, + .end = ibuf + lbuf, + .netdev = dev->netdev, + .pdev = container_of(dev, struct pcan_usb, dev), + }; + int err; + + for (err = 0; mc.rec_idx < mc.rec_cnt && !err; mc.rec_idx++) { + u8 sl = *mc.ptr++; + + /* handle status and error frames here */ + if (sl & PCAN_USB_STATUSLEN_INTERNAL) { + err = pcan_usb_decode_status(&mc, sl); + /* handle normal can frames here */ + } else { + err = pcan_usb_decode_data(&mc, sl); + } + } + + return err; +} + +/* + * process any incoming buffer + */ +static int pcan_usb_decode_buf(struct peak_usb_device *dev, struct urb *urb) +{ + int err = 0; + + if (urb->actual_length > PCAN_USB_MSG_HEADER_LEN) { + err = pcan_usb_decode_msg(dev, urb->transfer_buffer, + urb->actual_length); + + } else if (urb->actual_length > 0) { + netdev_err(dev->netdev, "usb message length error (%u)\n", + urb->actual_length); + err = -EINVAL; + } + + return err; +} + +/* + * process outgoing packet + */ +static int pcan_usb_encode_msg(struct peak_usb_device *dev, struct sk_buff *skb, + u8 *obuf, size_t *size) +{ + struct net_device *netdev = dev->netdev; + struct net_device_stats *stats = &netdev->stats; + struct can_frame *cf = (struct can_frame *)skb->data; + u8 *pc; + + obuf[0] = 2; + obuf[1] = 1; + + pc = obuf + PCAN_USB_MSG_HEADER_LEN; + + /* status/len byte */ + *pc = cf->can_dlc; + if (cf->can_id & CAN_RTR_FLAG) + *pc |= PCAN_USB_STATUSLEN_RTR; + + /* can id */ + if (cf->can_id & CAN_EFF_FLAG) { + __le32 tmp32 = cpu_to_le32((cf->can_id & CAN_ERR_MASK) << 3); + + *pc |= PCAN_USB_STATUSLEN_EXT_ID; + memcpy(++pc, &tmp32, 4); + pc += 4; + } else { + __le16 tmp16 = cpu_to_le16((cf->can_id & CAN_ERR_MASK) << 5); + + memcpy(++pc, &tmp16, 2); + pc += 2; + } + + /* can data */ + if (!(cf->can_id & CAN_RTR_FLAG)) { + memcpy(pc, cf->data, cf->can_dlc); + pc += cf->can_dlc; + } + + obuf[(*size)-1] = (u8)(stats->tx_packets & 0xff); + + return 0; +} + +/* socket callback used to copy berr counters values received through USB */ +static int pcan_usb_get_berr_counter(const struct net_device *netdev, + struct can_berr_counter *bec) +{ + struct peak_usb_device *dev = netdev_priv(netdev); + struct pcan_usb *pdev = container_of(dev, struct pcan_usb, dev); + + *bec = pdev->bec; + + /* must return 0 */ + return 0; +} + +/* + * start interface + */ +static int pcan_usb_start(struct peak_usb_device *dev) +{ + struct pcan_usb *pdev = container_of(dev, struct pcan_usb, dev); + int err; + + /* number of bits used in timestamps read from adapter struct */ + peak_usb_init_time_ref(&pdev->time_ref, &pcan_usb); + + pdev->bec.rxerr = 0; + pdev->bec.txerr = 0; + + /* be notified on error counter changes (if requested by user) */ + if (dev->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) { + err = pcan_usb_set_err_frame(dev, PCAN_USB_BERR_MASK); + if (err) + netdev_warn(dev->netdev, + "Asking for BERR reporting error %u\n", + err); + } + + /* if revision greater than 3, can put silent mode on/off */ + if (dev->device_rev > 3) { + err = pcan_usb_set_silent(dev, + dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY); + if (err) + return err; + } + + return pcan_usb_set_ext_vcc(dev, 0); +} + +static int pcan_usb_init(struct peak_usb_device *dev) +{ + struct pcan_usb *pdev = container_of(dev, struct pcan_usb, dev); + u32 serial_number; + int err; + + /* initialize a timer needed to wait for hardware restart */ + timer_setup(&pdev->restart_timer, pcan_usb_restart, 0); + + /* + * explicit use of dev_xxx() instead of netdev_xxx() here: + * information displayed are related to the device itself, not + * to the canx netdevice. + */ + err = pcan_usb_get_serial(dev, &serial_number); + if (err) { + dev_err(dev->netdev->dev.parent, + "unable to read %s serial number (err %d)\n", + pcan_usb.name, err); + return err; + } + + dev_info(dev->netdev->dev.parent, + "PEAK-System %s adapter hwrev %u serial %08X (%u channel)\n", + pcan_usb.name, dev->device_rev, serial_number, + pcan_usb.ctrl_count); + + return 0; +} + +/* + * probe function for new PCAN-USB usb interface + */ +static int pcan_usb_probe(struct usb_interface *intf) +{ + struct usb_host_interface *if_desc; + int i; + + if_desc = intf->altsetting; + + /* check interface endpoint addresses */ + for (i = 0; i < if_desc->desc.bNumEndpoints; i++) { + struct usb_endpoint_descriptor *ep = &if_desc->endpoint[i].desc; + + switch (ep->bEndpointAddress) { + case PCAN_USB_EP_CMDOUT: + case PCAN_USB_EP_CMDIN: + case PCAN_USB_EP_MSGOUT: + case PCAN_USB_EP_MSGIN: + break; + default: + return -ENODEV; + } + } + + return 0; +} + +/* + * describe the PCAN-USB adapter + */ +static const struct can_bittiming_const pcan_usb_const = { + .name = "pcan_usb", + .tseg1_min = 1, + .tseg1_max = 16, + .tseg2_min = 1, + .tseg2_max = 8, + .sjw_max = 4, + .brp_min = 1, + .brp_max = 64, + .brp_inc = 1, +}; + +const struct peak_usb_adapter pcan_usb = { + .name = "PCAN-USB", + .device_id = PCAN_USB_PRODUCT_ID, + .ctrl_count = 1, + .ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_LISTENONLY | + CAN_CTRLMODE_BERR_REPORTING, + .clock = { + .freq = PCAN_USB_CRYSTAL_HZ / 2 , + }, + .bittiming_const = &pcan_usb_const, + + /* size of device private data */ + .sizeof_dev_private = sizeof(struct pcan_usb), + + /* timestamps usage */ + .ts_used_bits = 16, + .ts_period = 24575, /* calibration period in ts. */ + .us_per_ts_scale = PCAN_USB_TS_US_PER_TICK, /* us=(ts*scale) */ + .us_per_ts_shift = PCAN_USB_TS_DIV_SHIFTER, /* >> shift */ + + /* give here messages in/out endpoints */ + .ep_msg_in = PCAN_USB_EP_MSGIN, + .ep_msg_out = {PCAN_USB_EP_MSGOUT}, + + /* size of rx/tx usb buffers */ + .rx_buffer_size = PCAN_USB_RX_BUFFER_SIZE, + .tx_buffer_size = PCAN_USB_TX_BUFFER_SIZE, + + /* device callbacks */ + .intf_probe = pcan_usb_probe, + .dev_init = pcan_usb_init, + .dev_set_bus = pcan_usb_write_mode, + .dev_set_bittiming = pcan_usb_set_bittiming, + .dev_get_device_id = pcan_usb_get_device_id, + .dev_decode_buf = pcan_usb_decode_buf, + .dev_encode_msg = pcan_usb_encode_msg, + .dev_start = pcan_usb_start, + .dev_restart_async = pcan_usb_restart_async, + .do_get_berr_counter = pcan_usb_get_berr_counter, +}; 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