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 <linux/of_address.h>
  22 #include <asm/io.h>
  23
  24 #include "emac.h"
  25 #include "core.h"
  26
  27 int tah_attach(struct platform_device *ofdev, int channel)
  28 {
  29         struct tah_instance *dev = platform_get_drvdata(ofdev);
  30
  31         mutex_lock(&dev->lock);
  32         /* Reset has been done at probe() time... nothing else to do for now */
  33         ++dev->users;
  34         mutex_unlock(&dev->lock);
  35
  36         return 0;
  37 }
  38
  39 void tah_detach(struct platform_device *ofdev, int channel)
  40 {
  41         struct tah_instance *dev = platform_get_drvdata(ofdev);
  42
  43         mutex_lock(&dev->lock);
  44         --dev->users;
  45         mutex_unlock(&dev->lock);
  46 }
  47
  48 void tah_reset(struct platform_device *ofdev)
  49 {
  50         struct tah_instance *dev = platform_get_drvdata(ofdev);
  51         struct tah_regs __iomem *p = dev->base;
  52         int n;
  53
  54         /* Reset TAH */
  55         out_be32(&p->mr, TAH_MR_SR);
  56         n = 100;
  57         while ((in_be32(&p->mr) & TAH_MR_SR) && n)
  58                 --n;
  59
  60         if (unlikely(!n))
  61                 printk(KERN_ERR "%s: reset timeout\n",
  62                         ofdev->dev.of_node->full_name);
  63
  64         /* 10KB TAH TX FIFO accommodates the max MTU of 9000 */
  65         out_be32(&p->mr,
  66                  TAH_MR_CVR | TAH_MR_ST_768 | TAH_MR_TFS_10KB | TAH_MR_DTFP |
  67                  TAH_MR_DIG);
  68 }
  69
  70 int tah_get_regs_len(struct platform_device *ofdev)
  71 {
  72         return sizeof(struct emac_ethtool_regs_subhdr) +
  73                 sizeof(struct tah_regs);
  74 }
  75
  76 void *tah_dump_regs(struct platform_device *ofdev, void *buf)
  77 {
  78         struct tah_instance *dev = platform_get_drvdata(ofdev);
  79         struct emac_ethtool_regs_subhdr *hdr = buf;
  80         struct tah_regs *regs = (struct tah_regs *)(hdr + 1);
  81
  82         hdr->version = 0;
  83         hdr->index = 0; /* for now, are there chips with more than one
  84                          * zmii ? if yes, then we'll add a cell_index
  85                          * like we do for emac
  86                          */
  87         memcpy_fromio(regs, dev->base, sizeof(struct tah_regs));
  88         return regs + 1;
  89 }
  90
  91 static int tah_probe(struct platform_device *ofdev)
  92 {
  93         struct device_node *np = ofdev->dev.of_node;
  94         struct tah_instance *dev;
  95         struct resource regs;
  96         int rc;
  97
  98         rc = -ENOMEM;
  99         dev = kzalloc(sizeof(struct tah_instance), GFP_KERNEL);
 100         if (dev == NULL)
 101                 goto err_gone;
 102
 103         mutex_init(&dev->lock);
 104         dev->ofdev = ofdev;
 105
 106         rc = -ENXIO;
 107         if (of_address_to_resource(np, 0, &regs)) {
 108                 printk(KERN_ERR "%s: Can't get registers address\n",
 109                        np->full_name);
 110                 goto err_free;
 111         }
 112
 113         rc = -ENOMEM;
 114         dev->base = (struct tah_regs __iomem *)ioremap(regs.start,
 115                                                sizeof(struct tah_regs));
 116         if (dev->base == NULL) {
 117                 printk(KERN_ERR "%s: Can't map device registers!\n",
 118                        np->full_name);
 119                 goto err_free;
 120         }
 121
 122         platform_set_drvdata(ofdev, dev);
 123
 124         /* Initialize TAH and enable IPv4 checksum verification, no TSO yet */
 125         tah_reset(ofdev);
 126
 127         printk(KERN_INFO
 128                "TAH %s initialized\n", ofdev->dev.of_node->full_name);
 129         wmb();
 130
 131         return 0;
 132
 133  err_free:
 134         kfree(dev);
 135  err_gone:
 136         return rc;
 137 }
 138
 139 static int tah_remove(struct platform_device *ofdev)
 140 {
 141         struct tah_instance *dev = platform_get_drvdata(ofdev);
 142
 143         WARN_ON(dev->users != 0);
 144
 145         iounmap(dev->base);
 146         kfree(dev);
 147
 148         return 0;
 149 }
 150
 151 static struct of_device_id tah_match[] =
 152 {
 153         {
 154                 .compatible     = "ibm,tah",
 155         },
 156         /* For backward compat with old DT */
 157         {
 158                 .type           = "tah",
 159         },
 160         {},
 161 };
 162
 163 static struct platform_driver tah_driver = {
 164         .driver = {
 165                 .name = "emac-tah",
 166                 .owner = THIS_MODULE,
 167                 .of_match_table = tah_match,
 168         },
 169         .probe = tah_probe,
 170         .remove = tah_remove,
 171 };
 172
 173 int __init tah_init(void)
 174 {
 175         return platform_driver_register(&tah_driver);
 176 }
 177
 178 void tah_exit(void)
 179 {
 180         platform_driver_unregister(&tah_driver);
 181 }