drivers/staging/sbe-2t3e3/main.c

   1 /*
   2  * SBE 2T3E3 synchronous serial card driver for Linux
   3  *
   4  * Copyright (C) 2009-2010 Krzysztof Halasa <khc@pm.waw.pl>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of version 2 of the GNU General Public License
   8  * as published by the Free Software Foundation.
   9  *
  10  * This code is based on a driver written by SBE Inc.
  11  */
  12
  13 #include <linux/interrupt.h>
  14 #include <linux/netdevice.h>
  15 #include "2t3e3.h"
  16
  17 void t3e3_init(struct channel *sc)
  18 {
  19         cpld_init(sc);
  20         dc_reset(sc);
  21         dc_init(sc);
  22         exar7250_init(sc);
  23         exar7300_init(sc);
  24 }
  25
  26 int t3e3_if_start_xmit(struct sk_buff *skb, struct net_device *dev)
  27 {
  28         struct channel *sc = dev_to_priv(dev);
  29         u32 current_write, last_write;
  30         unsigned long flags;
  31         struct sk_buff *skb2;
  32
  33         if (skb == NULL) {
  34                 sc->s.out_errors++;
  35                 return 0;
  36         }
  37
  38         if (sc->p.transmitter_on != SBE_2T3E3_ON) {
  39                 sc->s.out_errors++;
  40                 sc->s.out_dropped++;
  41                 dev_kfree_skb_any(skb);
  42                 return 0;
  43         }
  44
  45         if (sc->s.OOF && sc->p.loopback == SBE_2T3E3_LOOPBACK_NONE) {
  46                 sc->s.out_dropped++;
  47                 dev_kfree_skb_any(skb);
  48                 return 0;
  49         }
  50
  51         spin_lock_irqsave(&sc->ether.tx_lock, flags);
  52
  53         current_write = sc->ether.tx_ring_current_write;
  54         for (skb2 = skb; skb2 != NULL; skb2 = NULL) {
  55                 if (skb2->len) {
  56                         if ((sc->ether.tx_ring[current_write].tdes1 &
  57                              SBE_2T3E3_TX_DESC_BUFFER_1_SIZE) > 0)
  58                                 break;
  59                         current_write = (current_write + 1) % SBE_2T3E3_TX_DESC_RING_SIZE;
  60                         /*
  61                          * Leave at least 1 tx desc free so that dc_intr_tx() can
  62                          * identify empty list
  63                          */
  64                         if (current_write == sc->ether.tx_ring_current_read)
  65                                 break;
  66                 }
  67         }
  68         if (skb2 != NULL) {
  69                 netif_stop_queue(sc->dev);
  70                 sc->ether.tx_full = 1;
  71                 dev_dbg(&sc->pdev->dev, "SBE 2T3E3: out of descriptors\n");
  72                 spin_unlock_irqrestore(&sc->ether.tx_lock, flags);
  73                 return NETDEV_TX_BUSY;
  74         }
  75
  76         current_write = last_write = sc->ether.tx_ring_current_write;
  77         dev_dbg(&sc->pdev->dev, "sending mbuf (current_write = %d)\n",
  78                 current_write);
  79
  80         for (skb2 = skb; skb2 != NULL; skb2 = NULL) {
  81                 if (skb2->len) {
  82                         dev_dbg(&sc->pdev->dev,
  83                                 "sending mbuf (len = %d, next = %p)\n",
  84                                 skb2->len, NULL);
  85
  86                         sc->ether.tx_free_cnt--;
  87                         sc->ether.tx_ring[current_write].tdes0 = 0;
  88                         sc->ether.tx_ring[current_write].tdes1 &=
  89                                 SBE_2T3E3_TX_DESC_END_OF_RING |
  90                                 SBE_2T3E3_TX_DESC_SECOND_ADDRESS_CHAINED;
  91 /* DISABLE_PADDING sometimes gets lost somehow, hands off... */
  92                         sc->ether.tx_ring[current_write].tdes1 |=
  93                                 SBE_2T3E3_TX_DESC_DISABLE_PADDING | skb2->len;
  94
  95                         if (current_write == sc->ether.tx_ring_current_write) {
  96                                 sc->ether.tx_ring[current_write].tdes1 |=
  97                                         SBE_2T3E3_TX_DESC_FIRST_SEGMENT;
  98                         } else {
  99                                 sc->ether.tx_ring[current_write].tdes0 =
 100                                         SBE_2T3E3_TX_DESC_21143_OWN;
 101                         }
 102
 103                         sc->ether.tx_ring[current_write].tdes2 = virt_to_phys(skb2->data);
 104                         sc->ether.tx_data[current_write] = NULL;
 105
 106                         last_write = current_write;
 107                         current_write = (current_write + 1) % SBE_2T3E3_TX_DESC_RING_SIZE;
 108                 }
 109         }
 110
 111         sc->ether.tx_data[last_write] = skb;
 112         sc->ether.tx_ring[last_write].tdes1 |=
 113                 SBE_2T3E3_TX_DESC_LAST_SEGMENT |
 114                 SBE_2T3E3_TX_DESC_INTERRUPT_ON_COMPLETION;
 115         sc->ether.tx_ring[sc->ether.tx_ring_current_write].tdes0 |=
 116                 SBE_2T3E3_TX_DESC_21143_OWN;
 117         sc->ether.tx_ring_current_write = current_write;
 118
 119         dev_dbg(&sc->pdev->dev, "txput: tdes0 = %08X        tdes1 = %08X\n",
 120                 sc->ether.tx_ring[last_write].tdes0,
 121                 sc->ether.tx_ring[last_write].tdes1);
 122
 123         dc_write(sc->addr, SBE_2T3E3_21143_REG_TRANSMIT_POLL_DEMAND,
 124                  0xffffffff);
 125
 126         spin_unlock_irqrestore(&sc->ether.tx_lock, flags);
 127         return 0;
 128 }
 129
 130
 131 void t3e3_read_card_serial_number(struct channel *sc)
 132 {
 133         u32 i;
 134
 135         for (i = 0; i < 3; i++)
 136                 sc->ether.card_serial_number[i] = t3e3_eeprom_read_word(sc, 10 + i);
 137
 138         netdev_info(sc->dev, "SBE wanPMC-2T3E3 serial number: %04X%04X%04X\n",
 139                     sc->ether.card_serial_number[0],
 140                     sc->ether.card_serial_number[1],
 141                     sc->ether.card_serial_number[2]);
 142 }
 143
 144 /*
 145   bit 0 led1 (green)
 146   bit 1 led1 (yellow)
 147
 148   bit 2 led2 (green)
 149   bit 3 led2 (yellow)
 150
 151   bit 4 led3 (green)
 152   bit 5 led3 (yellow)
 153
 154   bit 6 led4 (green)
 155   bit 7 led4 (yellow)
 156 */
 157
 158 void update_led(struct channel *sc, int blinker)
 159 {
 160         int leds;
 161         if (sc->s.LOS)
 162                 leds = 0; /* led1 = off */
 163         else if (sc->s.OOF)
 164                 leds = 2; /* led1 = yellow */
 165         else if ((blinker & 1) && sc->rcv_count) {
 166                 leds = 0; /* led1 = off */
 167                 sc->rcv_count = 0;
 168         } else
 169                 leds = 1; /* led1 = green */
 170         cpld_write(sc, SBE_2T3E3_CPLD_REG_LEDR, leds);
 171         sc->leds = leds;
 172 }