drivers/net/ethernet/ibm/emac/tah.c

   1 /*
   2  * drivers/net/ethernet/ibm/emac/tah.c
   3  *
   4  * Driver for PowerPC 4xx on-chip ethernet controller, TAH support.
   5  *
   6  * Copyright 2007 Benjamin Herrenschmidt, IBM Corp.
   7  *                <benh@kernel.crashing.org>
   8  *
   9  * Based on the arch/ppc version of the driver:
  10  *
  11  * Copyright 2004 MontaVista Software, Inc.
  12  * Matt Porter <mporter@kernel.crashing.org>
  13  *
  14  * Copyright (c) 2005 Eugene Surovegin <ebs@ebshome.net>
  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 #include <asm/io.h>
  22
  23 #include "emac.h"
  24 #include "core.h"
  25
  26 int tah_attach(struct platform_device *ofdev, int channel)
  27 {
  28         struct tah_instance *dev = platform_get_drvdata(ofdev);
  29
  30         mutex_lock(&dev->lock);
  31         /* Reset has been done at probe() time... nothing else to do for now */
  32         ++dev->users;
  33         mutex_unlock(&dev->lock);
  34
  35         return 0;
  36 }
  37
  38 void tah_detach(struct platform_device *ofdev, int channel)
  39 {
  40         struct tah_instance *dev = platform_get_drvdata(ofdev);
  41
  42         mutex_lock(&dev->lock);
  43         --dev->users;
  44         mutex_unlock(&dev->lock);
  45 }
  46
  47 void tah_reset(struct platform_device *ofdev)
  48 {
  49         struct tah_instance *dev = platform_get_drvdata(ofdev);
  50         struct tah_regs __iomem *p = dev->base;
  51         int n;
  52
  53         /* Reset TAH */
  54         out_be32(&p->mr, TAH_MR_SR);
  55         n = 100;
  56         while ((in_be32(&p->mr) & TAH_MR_SR) && n)
  57                 --n;
  58
  59         if (unlikely(!n))
  60                 printk(KERN_ERR "%s: reset timeout\n",
  61                         ofdev->dev.of_node->full_name);
  62
  63         /* 10KB TAH TX FIFO accommodates the max MTU of 9000 */
  64         out_be32(&p->mr,
  65                  TAH_MR_CVR | TAH_MR_ST_768 | TAH_MR_TFS_10KB | TAH_MR_DTFP |
  66                  TAH_MR_DIG);
  67 }
  68
  69 int tah_get_regs_len(struct platform_device *ofdev)
  70 {
  71         return sizeof(struct emac_ethtool_regs_subhdr) +
  72                 sizeof(struct tah_regs);
  73 }
  74
  75 void *tah_dump_regs(struct platform_device *ofdev, void *buf)
  76 {
  77         struct tah_instance *dev = platform_get_drvdata(ofdev);
  78         struct emac_ethtool_regs_subhdr *hdr = buf;
  79         struct tah_regs *regs = (struct tah_regs *)(hdr + 1);
  80
  81         hdr->version = 0;
  82         hdr->index = 0; /* for now, are there chips with more than one
  83                          * zmii ? if yes, then we'll add a cell_index
  84                          * like we do for emac
  85                          */
  86         memcpy_fromio(regs, dev->base, sizeof(struct tah_regs));
  87         return regs + 1;
  88 }
  89
  90 static int tah_probe(struct platform_device *ofdev)
  91 {
  92         struct device_node *np = ofdev->dev.of_node;
  93         struct tah_instance *dev;
  94         struct resource regs;
  95         int rc;
  96
  97         rc = -ENOMEM;
  98         dev = kzalloc(sizeof(struct tah_instance), GFP_KERNEL);
  99         if (dev == NULL)
 100                 goto err_gone;
 101
 102         mutex_init(&dev->lock);
 103         dev->ofdev = ofdev;
 104
 105         rc = -ENXIO;
 106         if (of_address_to_resource(np, 0, &regs)) {
 107                 printk(KERN_ERR "%s: Can't get registers address\n",
 108                        np->full_name);
 109                 goto err_free;
 110         }
 111
 112         rc = -ENOMEM;
 113         dev->base = (struct tah_regs __iomem *)ioremap(regs.start,
 114                                                sizeof(struct tah_regs));
 115         if (dev->base == NULL) {
 116                 printk(KERN_ERR "%s: Can't map device registers!\n",
 117                        np->full_name);
 118                 goto err_free;
 119         }
 120
 121         platform_set_drvdata(ofdev, dev);
 122
 123         /* Initialize TAH and enable IPv4 checksum verification, no TSO yet */
 124         tah_reset(ofdev);
 125
 126         printk(KERN_INFO
 127                "TAH %s initialized\n", ofdev->dev.of_node->full_name);
 128         wmb();
 129
 130         return 0;
 131
 132  err_free:
 133         kfree(dev);
 134  err_gone:
 135         return rc;
 136 }
 137
 138 static int tah_remove(struct platform_device *ofdev)
 139 {
 140         struct tah_instance *dev = platform_get_drvdata(ofdev);
 141
 142         WARN_ON(dev->users != 0);
 143
 144         iounmap(dev->base);
 145         kfree(dev);
 146
 147         return 0;
 148 }
 149
 150 static struct of_device_id tah_match[] =
 151 {
 152         {
 153                 .compatible     = "ibm,tah",
 154         },
 155         /* For backward compat with old DT */
 156         {
 157                 .type           = "tah",
 158         },
 159         {},
 160 };
 161
 162 static struct platform_driver tah_driver = {
 163         .driver = {
 164                 .name = "emac-tah",
 165                 .owner = THIS_MODULE,
 166                 .of_match_table = tah_match,
 167         },
 168         .probe = tah_probe,
 169         .remove = tah_remove,
 170 };
 171
 172 int __init tah_init(void)
 173 {
 174         return platform_driver_register(&tah_driver);
 175 }
 176
 177 void tah_exit(void)
 178 {
 179         platform_driver_unregister(&tah_driver);
 180 }