Function efm_eth_rx

bsp/efm32/drv_ethernet.c:712–825

/ * @brief * Packet receiving function * * @details * * @note * * @param[in] dev * Pointer to device descriptor * * @return * Pointer to packet buffer ******************************************************************************/

*   Pointer to packet buffer
******************************************************************************/
struct pbuf *efm_eth_rx(rt_device_t dev)
{
    rt_uint8_t buf_ins[5], buf_read[6];
    rt_uint8_t data, reg_eie;
    rt_uint16_t len_rx, sta_rx;
    struct pbuf* p;

    /* Lock device */
    rt_sem_take(&ethLock, RT_WAITING_FOREVER);

    /* Disable interrupts */
    data = EIE_INTIE;
    efm_eth_sendCmd(ENC28J60_BIT_FIELD_CLR, EIE, &data);

    p = RT_NULL;
    reg_eie = 0;
    if (efm_eth_readReg(EPKTCNT))
    {
        /* Set read pointer to the start of RX packet */
        efm_eth_writeReg(ERDPTL, ethNxtPkt & 0xFF);
        efm_eth_writeReg(ERDPTH, ethNxtPkt >> 8);

        /* Send read buffer command */
        efm_eth_sendCmd(ENC28J60_READ_BUF_MEM, EFM32_NO_DATA, EFM32_NO_POINTER);
        /* Build instruction buffer */
        buf_ins[0] = 0x00;
        *(rt_uint8_t **)(&buf_ins[1]) = buf_read;
        /* Read packet header */
        if (spi->read(spi, EFM32_NO_DATA, buf_ins, sizeof(buf_read)) == 0)
        {
            eth_debug("ETH: RX header failed!\n");
        }

        ethNxtPkt = buf_read[0] | (buf_read[1] << 8);
        len_rx = buf_read[2] | (buf_read[3] << 8);
        sta_rx = buf_read[4] | (buf_read[5] << 8);
        eth_debug("ETH: RX header ethNxtPkt %x, len_rx %x, sta_rx %x\n",
            ethNxtPkt, len_rx, sta_rx);
        /* Check if OK */
        if (sta_rx & 0x80)
        {
            /* Allocate pbuf */
            p = pbuf_alloc(PBUF_LINK, len_rx - 4, PBUF_RAM);
            if (p != RT_NULL)
            {
                struct pbuf* q;

                for (q = p; q != RT_NULL; q= q->next)
                {
                    /* Build instruction buffer */
                    buf_ins[0] = 0x00;
                    *(rt_uint8_t **)(&buf_ins[1]) = q->payload;
                    /* Read packet header */
                    if (spi->read(spi, EFM32_NO_DATA, buf_ins, q->len) == 0)
                    {
                        eth_debug("ETH: RX payload failed!\n");
                    }
#ifdef EFM32_ETHERNET_DEBUG