drivers/net/xilinx_ll_temac_fifo.c

   1 /*
   2  * Xilinx xps_ll_temac ethernet driver for u-boot
   3  *
   4  * FIFO sub-controller
   5  *
   6  * Copyright (C) 2011 - 2012 Stephan Linz <linz@li-pro.net>
   7  * Copyright (C) 2008 - 2011 Michal Simek <monstr@monstr.eu>
   8  * Copyright (C) 2008 - 2011 PetaLogix
   9  *
  10  * Based on Yoshio Kashiwagi kashiwagi@co-nss.co.jp driver
  11  * Copyright (C) 2008 Nissin Systems Co.,Ltd.
  12  * March 2008 created
  13  *
  14  * CREDITS: tsec driver
  15  *
  16  * This program is free software; you can redistribute it and/or modify it
  17  * under the terms of the GNU General Public License as published by the
  18  * Free Software Foundation; either version 2 of the License, or (at your
  19  * option) any later version.
  20  *
  21  * [0]: http://www.xilinx.com/support/documentation
  22  *
  23  * [F]: [0]/ip_documentation/xps_ll_fifo.pdf
  24  * [S]: [0]/ip_documentation/xps_ll_temac.pdf
  25  * [A]: [0]/application_notes/xapp1041.pdf
  26  */
  27
  28 #include <config.h>
  29 #include <common.h>
  30 #include <net.h>
  31
  32 #include <asm/types.h>
  33 #include <asm/io.h>
  34
  35 #include "xilinx_ll_temac.h"
  36 #include "xilinx_ll_temac_fifo.h"
  37
  38 int ll_temac_reset_fifo(struct eth_device *dev)
  39 {
  40         struct ll_temac *ll_temac = dev->priv;
  41         struct fifo_ctrl *fifo_ctrl = (void *)ll_temac->ctrladdr;
  42
  43         out_be32(&fifo_ctrl->tdfr, LL_FIFO_TDFR_KEY);
  44         out_be32(&fifo_ctrl->rdfr, LL_FIFO_RDFR_KEY);
  45         out_be32(&fifo_ctrl->isr, ~0UL);
  46         out_be32(&fifo_ctrl->ier, 0);
  47
  48         return 0;
  49 }
  50
  51 int ll_temac_recv_fifo(struct eth_device *dev)
  52 {
  53         int i, length = 0;
  54         u32 *buf = (u32 *)NetRxPackets[0];
  55         struct ll_temac *ll_temac = dev->priv;
  56         struct fifo_ctrl *fifo_ctrl = (void *)ll_temac->ctrladdr;
  57
  58         if (in_be32(&fifo_ctrl->isr) & LL_FIFO_ISR_RC) {
  59
  60                 /* reset isr */
  61                 out_be32(&fifo_ctrl->isr, ~0UL);
  62
  63                 /*
  64                  * MAYBE here:
  65                  *   while (fifo_ctrl->isr);
  66                  */
  67
  68                 /*
  69                  * The length is written (into RLR) by the XPS LL FIFO
  70                  * when the packet is received across the RX LocalLink
  71                  * interface and the receive data FIFO had enough
  72                  * locations that all of the packet data has been saved.
  73                  * The RLR should only be read when a receive packet is
  74                  * available for processing (the receive occupancy is
  75                  * not zero). Once the RLR is read, the receive packet
  76                  * data should be read from the receive data FIFO before
  77                  * the RLR is read again.
  78                  *
  79                  * [F] page 17, Receive Length Register (RLR)
  80                  */
  81                 if (in_be32(&fifo_ctrl->rdfo) & LL_FIFO_RDFO_MASK) {
  82                         length = in_be32(&fifo_ctrl->rlf) & LL_FIFO_RLF_MASK;
  83                 } else {
  84                         printf("%s: Got error, no receive occupancy\n",
  85                                         __func__);
  86                         return -1;
  87                 }
  88
  89                 if (length > PKTSIZE_ALIGN) {
  90                         printf("%s: Got error, receive package too big (%i)\n",
  91                                         __func__, length);
  92                         ll_temac_reset_fifo(dev);
  93                         return -1;
  94                 }
  95
  96                 for (i = 0; i < length; i += 4)
  97                         *buf++ = in_be32(&fifo_ctrl->rdfd);
  98
  99                 NetReceive(NetRxPackets[0], length);
 100         }
 101
 102         return 0;
 103 }
 104
 105 int ll_temac_send_fifo(struct eth_device *dev, void *packet, int length)
 106 {
 107         int i;
 108         u32 *buf = (u32 *)packet;
 109         struct ll_temac *ll_temac = dev->priv;
 110         struct fifo_ctrl *fifo_ctrl = (void *)ll_temac->ctrladdr;
 111
 112         if (length < LL_FIFO_TLF_MIN) {
 113                 printf("%s: Got error, transmit package too small (%i)\n",
 114                                 __func__, length);
 115                 return -1;
 116         }
 117
 118         if (length > LL_FIFO_TLF_MAX) {
 119                 printf("%s: Got error, transmit package too big (%i)\n",
 120                                 __func__, length);
 121                 return -1;
 122         }
 123
 124         for (i = 0; i < length; i += 4)
 125                 out_be32(&fifo_ctrl->tdfd, *buf++);
 126
 127         /*
 128          * Once the packet length is written to the TLR it is
 129          * automatically moved to the transmit data FIFO with
 130          * the packet data freeing up the TLR for another value.
 131          * The packet length must be written to the TLR after
 132          * the packet data is written to the transmit data FIFO.
 133          * It is not valid to write data for multiple packets
 134          * to the transmit data FIFO before writing the packet
 135          * length values.
 136          *
 137          * [F] page 17, Transmit Length Register (TLR)
 138          */
 139         out_be32(&fifo_ctrl->tlf, length);
 140
 141         return 0;
 142 }