/*
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* Copyright (C) 2006 Jan Kiszka <jan.kiszka@web.de>
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*
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software Foundation,
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* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#include <linux/module.h>
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#include <rtdm/driver.h>
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#include <rtdm/can.h>
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#include "rtcan_dev.h"
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#include "rtcan_raw.h"
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#define RTCAN_DEV_NAME "rtcan%d"
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#define RTCAN_DRV_NAME "VIRT"
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#define RTCAN_MAX_VIRT_DEVS 8
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#define VIRT_TX_BUFS 1
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static char *virt_ctlr_name = "<virtual>";
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static char *virt_board_name = "<virtual>";
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MODULE_AUTHOR("Jan Kiszka <jan.kiszka@web.de>");
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MODULE_DESCRIPTION("Virtual RT-Socket-CAN driver");
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MODULE_LICENSE("GPL");
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static unsigned int devices = 2;
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module_param(devices, uint, 0400);
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MODULE_PARM_DESC(devices, "Number of devices on the virtual bus");
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static struct rtcan_device *rtcan_virt_devs[RTCAN_MAX_VIRT_DEVS];
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static int rtcan_virt_start_xmit(struct rtcan_device *tx_dev,
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can_frame_t *tx_frame)
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{
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int i;
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struct rtcan_device *rx_dev;
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struct rtcan_skb skb;
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struct rtcan_rb_frame *rx_frame = &skb.rb_frame;
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rtdm_lockctx_t lock_ctx;
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/* we can transmit immediately again */
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rtdm_sem_up(&tx_dev->tx_sem);
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tx_dev->tx_count++;
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skb.rb_frame_size = EMPTY_RB_FRAME_SIZE;
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rx_frame->can_dlc = tx_frame->can_dlc;
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rx_frame->can_id = tx_frame->can_id;
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if (!(tx_frame->can_id & CAN_RTR_FLAG)) {
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memcpy(rx_frame->data, tx_frame->data, tx_frame->can_dlc);
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skb.rb_frame_size += tx_frame->can_dlc;
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}
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rtdm_lock_get_irqsave(&rtcan_recv_list_lock, lock_ctx);
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rtdm_lock_get(&rtcan_socket_lock);
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/* Deliver to all other devices on the virtual bus */
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for (i = 0; i < devices; i++) {
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rx_dev = rtcan_virt_devs[i];
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if (rx_dev->state == CAN_STATE_ACTIVE) {
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if (tx_dev != rx_dev) {
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rx_frame->can_ifindex = rx_dev->ifindex;
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rtcan_rcv(rx_dev, &skb);
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} else if (rtcan_loopback_pending(tx_dev))
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rtcan_loopback(tx_dev);
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}
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}
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rtdm_lock_put(&rtcan_socket_lock);
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rtdm_lock_put_irqrestore(&rtcan_recv_list_lock, lock_ctx);
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return 0;
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}
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static int rtcan_virt_set_mode(struct rtcan_device *dev, can_mode_t mode,
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rtdm_lockctx_t *lock_ctx)
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{
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int err = 0;
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switch (mode) {
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case CAN_MODE_STOP:
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dev->state = CAN_STATE_STOPPED;
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/* Wake up waiting senders */
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rtdm_sem_destroy(&dev->tx_sem);
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break;
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case CAN_MODE_START:
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rtdm_sem_init(&dev->tx_sem, VIRT_TX_BUFS);
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dev->state = CAN_STATE_ACTIVE;
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break;
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default:
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err = -EOPNOTSUPP;
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}
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return err;
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}
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static int __init rtcan_virt_init_one(int idx)
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{
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struct rtcan_device *dev;
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int err;
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if ((dev = rtcan_dev_alloc(0, 0)) == NULL)
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return -ENOMEM;
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dev->ctrl_name = virt_ctlr_name;
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dev->board_name = virt_board_name;
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rtcan_virt_set_mode(dev, CAN_MODE_STOP, NULL);
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strncpy(dev->name, RTCAN_DEV_NAME, IFNAMSIZ);
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dev->hard_start_xmit = rtcan_virt_start_xmit;
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dev->do_set_mode = rtcan_virt_set_mode;
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/* Register RTDM device */
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err = rtcan_dev_register(dev);
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if (err) {
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printk(KERN_ERR "ERROR %d while trying to register RTCAN device!\n", err);
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goto error_out;
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}
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/* Remember initialized devices */
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rtcan_virt_devs[idx] = dev;
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printk("%s: %s driver loaded\n", dev->name, RTCAN_DRV_NAME);
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return 0;
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error_out:
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rtcan_dev_free(dev);
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return err;
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}
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/** Init module */
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static int __init rtcan_virt_init(void)
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{
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int i, err = 0;
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if (!rtdm_available())
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return -ENOSYS;
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for (i = 0; i < devices; i++) {
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err = rtcan_virt_init_one(i);
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if (err) {
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while (--i >= 0) {
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struct rtcan_device *dev = rtcan_virt_devs[i];
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rtcan_dev_unregister(dev);
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rtcan_dev_free(dev);
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}
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break;
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}
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}
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return err;
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}
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/** Cleanup module */
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static void __exit rtcan_virt_exit(void)
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{
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int i;
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struct rtcan_device *dev;
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for (i = 0; i < devices; i++) {
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dev = rtcan_virt_devs[i];
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printk("Unloading %s device %s\n", RTCAN_DRV_NAME, dev->name);
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rtcan_virt_set_mode(dev, CAN_MODE_STOP, NULL);
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rtcan_dev_unregister(dev);
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rtcan_dev_free(dev);
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}
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}
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module_init(rtcan_virt_init);
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module_exit(rtcan_virt_exit);
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