close.c

HMS30C7202下的CAN驱动

/** close.c
 *
 * Written by Sebastian Stolzenberg email:[e-mail]
 * Version 1.0  04 Feb 2003
 */

#ifndef __KERNEL__
# define __KERNEL__
#endif
#ifndef MODULE
# define MODULE
#endif

#include <linux/module.h>
#include "../include/candrv.h"
#include "../include/hms30c7202_can.h"
#include "../include/c_can.h"
#include "../include/irq.h"

///////////////////////////////////////////////////////////////////////////////
/**
 * Close function called by the user.
 */

int can_close( struct inode *inode, struct file *filp )
{
        struct msgobj_t *pmsgobj = NULL;

        unsigned short tempreg = 0;
        unsigned short readMaskCM = IFXCM_CNTRL | IFXCM_ARB;
        unsigned short writeMaskCM = IFXCM_CNTRL | IFXCM_ARB;

        /* Check if message object exists */
        if ( NULL == ( pmsgobj = filp->private_data )) {
                CANMSG("No object defined");
                return -ENODEV;
        }

        /* Wait for end sending and receiving process */
        while ( ( pmsgobj->fifo->flags & (TX_IN_PROGRESS | RX_IN_PROGRESS) ) &&
                !(pmsgobj->hostchip->chip_status & SR_EPASS) )
                CANMSG("Still working");

        spin_lock( &pmsgobj->hostchip->if1lock );

        /* load Message Object in IF1 */
        if (c_can_if1_busycheck(pmsgobj->hostchip)) return -ENODEV;
        pmsgobj->hostchip->write_register(readMaskCM, pmsgobj->hostchip, CCIF1CM);
        pmsgobj->hostchip->write_register(pmsgobj->object+1, pmsgobj->hostchip, CCIF1CR);

        /* setting Message Valid Bit to zero */
        if (c_can_if1_busycheck(pmsgobj->hostchip)) return -ENODEV;
        tempreg = pmsgobj->hostchip->read_register(pmsgobj->hostchip, CCIF1A2);
        pmsgobj->hostchip->write_register(tempreg & ~IFXARB2_MVAL, pmsgobj->hostchip, CCIF1A2);
        pmsgobj->hostchip->write_register(writeMaskCM, pmsgobj->hostchip, CCIF1CM);
        pmsgobj->hostchip->write_register(pmsgobj->object+1, pmsgobj->hostchip, CCIF1CR);

        spin_unlock( &pmsgobj->hostchip->if1lock );


        /* Reset flags */
        pmsgobj->flags &= ~CHANNEL_OPENED;

        pmsgobj->hostchip->active_obj_cnt--;
        /* release chip io and interrupt if no message object is active anymore */
        if (pmsgobj->hostchip->active_obj_cnt == 0) {

                if ( ! pmsgobj->hostchip->time_triggered ) {
                        /* disable interrupt generation */
                        c_can_config_irqs(pmsgobj->hostchip, 0);
                        /* Free the interrupt */
                        free_irq( pmsgobj->hostchip->irq, pmsgobj->hostchip );
                }

                if ( pmsgobj->hostchip->time_triggered ||
                     (pmsgobj->hostchip->chip_status & (SR_EPASS | SR_BOFF)) ) {
                        stop_time_trig(pmsgobj->hostchip);
                }

                /* Release I/O */
                pmsgobj->hostchip->release_io( pmsgobj->hostchip );

                /* Reset flags */
                pmsgobj->hostchip->flags &= ~CHANNEL_OPENED;
                pmsgobj->hostchip->flags &= ~CHANNEL_CONFIGURED;
        }

        if (NULL != pmsgobj->fifo) {

                /* Give up tx message buffer memory */
                if ( NULL != pmsgobj->fifo->ptxbuf ) {
                        del_mem_from_list( pmsgobj->fifo->ptxbuf );
                } else {
                        CANMSG("pmsgobj->fifo->buf_tx_entry is NULL");
                }

                /* Give up rx message buffer memory */
                if ( NULL != pmsgobj->fifo->prxbuf ) {
                        del_mem_from_list( pmsgobj->fifo->prxbuf );
                } else {
                        CANMSG("pmsgobj->fifo->buf_rx_entry is NULL");
                }

                /* Give up fifo memory */
                del_mem_from_list( pmsgobj->fifo );

        } else
                CANMSG("pmsg->fifo is NULL");

        MOD_DEC_USE_COUNT;

        return 0;
}