main.c

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/*
 * SBE 2T3E3 synchronous serial card driver for Linux
 *
 * Copyright (C) 2009-2010 Krzysztof Halasa <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License
 * as published by the Free Software Foundation.
 *
 * This code is based on a driver written by SBE Inc.
 */

#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include "2t3e3.h"

void t3e3_init(struct channel *sc)
{
    cpld_init(sc);
    dc_reset(sc);
    dc_init(sc);
    exar7250_init(sc);
    exar7300_init(sc);
}

int t3e3_if_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
    struct channel *sc = dev_to_priv(dev);
    u32 current_write, last_write;
    unsigned long flags;
    struct sk_buff *skb2;

    if (skb == NULL) {
        sc->s.out_errors++;
        return 0;
    }

    if (sc->p.transmitter_on != SBE_2T3E3_ON) {
        sc->s.out_errors++;
        sc->s.out_dropped++;
        dev_kfree_skb_any(skb);
        return 0;
    }

    if (sc->s.OOF && sc->p.loopback == SBE_2T3E3_LOOPBACK_NONE) {
        sc->s.out_dropped++;
        dev_kfree_skb_any(skb);
        return 0;
    }

    spin_lock_irqsave(&sc->ether.tx_lock, flags);

    current_write = sc->ether.tx_ring_current_write;
    for (skb2 = skb; skb2 != NULL; skb2 = NULL) {
        if (skb2->len) {
            if ((sc->ether.tx_ring[current_write].tdes1 &
                 SBE_2T3E3_TX_DESC_BUFFER_1_SIZE) > 0)
                break;
            current_write = (current_write + 1) % SBE_2T3E3_TX_DESC_RING_SIZE;
            /*
             * Leave at least 1 tx desc free so that dc_intr_tx() can
             * identify empty list
             */
            if (current_write == sc->ether.tx_ring_current_read)
                break;
        }
    }
    if (skb2 != NULL) {
        netif_stop_queue(sc->dev);
        sc->ether.tx_full = 1;
        dev_dbg(&sc->pdev->dev, "SBE 2T3E3: out of descriptors\n");
        spin_unlock_irqrestore(&sc->ether.tx_lock, flags);
        return NETDEV_TX_BUSY;
    }

    current_write = last_write = sc->ether.tx_ring_current_write;
    dev_dbg(&sc->pdev->dev, "sending mbuf (current_write = %d)\n",
        current_write);

    for (skb2 = skb; skb2 != NULL; skb2 = NULL) {
        if (skb2->len) {
            dev_dbg(&sc->pdev->dev,
                "sending mbuf (len = %d, next = %p)\n",
                skb2->len, NULL);

            sc->ether.tx_free_cnt--;
            sc->ether.tx_ring[current_write].tdes0 = 0;
            sc->ether.tx_ring[current_write].tdes1 &=
                SBE_2T3E3_TX_DESC_END_OF_RING |
                SBE_2T3E3_TX_DESC_SECOND_ADDRESS_CHAINED;
/* DISABLE_PADDING sometimes gets lost somehow, hands off... */
            sc->ether.tx_ring[current_write].tdes1 |=
                SBE_2T3E3_TX_DESC_DISABLE_PADDING | skb2->len;

            if (current_write == sc->ether.tx_ring_current_write) {
                sc->ether.tx_ring[current_write].tdes1 |=
                    SBE_2T3E3_TX_DESC_FIRST_SEGMENT;
            } else {
                sc->ether.tx_ring[current_write].tdes0 =
                    SBE_2T3E3_TX_DESC_21143_OWN;
            }

            sc->ether.tx_ring[current_write].tdes2 = virt_to_phys(skb2->data);
            sc->ether.tx_data[current_write] = NULL;

            last_write = current_write;
            current_write = (current_write + 1) % SBE_2T3E3_TX_DESC_RING_SIZE;
        }
    }

    sc->ether.tx_data[last_write] = skb;
    sc->ether.tx_ring[last_write].tdes1 |=
        SBE_2T3E3_TX_DESC_LAST_SEGMENT |
        SBE_2T3E3_TX_DESC_INTERRUPT_ON_COMPLETION;
    sc->ether.tx_ring[sc->ether.tx_ring_current_write].tdes0 |=
        SBE_2T3E3_TX_DESC_21143_OWN;
    sc->ether.tx_ring_current_write = current_write;

    dev_dbg(&sc->pdev->dev, "txput: tdes0 = %08X        tdes1 = %08X\n",
        sc->ether.tx_ring[last_write].tdes0,
        sc->ether.tx_ring[last_write].tdes1);

    dc_write(sc->addr, SBE_2T3E3_21143_REG_TRANSMIT_POLL_DEMAND,
         0xffffffff);

    spin_unlock_irqrestore(&sc->ether.tx_lock, flags);
    return 0;
}


void t3e3_read_card_serial_number(struct channel *sc)
{
    u32 i;

    for (i = 0; i < 3; i++)
        sc->ether.card_serial_number[i] = t3e3_eeprom_read_word(sc, 10 + i);

    printk(KERN_INFO "SBE wanPMC-2T3E3 serial number: %04X%04X%04X\n",
           sc->ether.card_serial_number[0], sc->ether.card_serial_number[1],
           sc->ether.card_serial_number[2]);
}

/*
  bit 0 led1 (green)
  bit 1 led1 (yellow)

  bit 2 led2 (green)
  bit 3 led2 (yellow)

  bit 4 led3 (green)
  bit 5 led3 (yellow)

  bit 6 led4 (green)
  bit 7 led4 (yellow)
*/

void update_led(struct channel *sc, int blinker)
{
    int leds;
    if (sc->s.LOS)
        leds = 0; /* led1 = off */
    else if (sc->s.OOF)
        leds = 2; /* led1 = yellow */
    else if ((blinker & 1) && sc->rcv_count) {
        leds = 0; /* led1 = off */
        sc->rcv_count = 0;
    } else
        leds = 1; /* led1 = green */
    cpld_write(sc, SBE_2T3E3_CPLD_REG_LEDR, leds);
    sc->leds = leds;
}