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 "%pOF: reset timeout\n", ofdev->dev.of_node);
  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 "%pOF: Can't get registers address\n", np);
 108                 goto err_free;
 109         }
 110
 111         rc = -ENOMEM;
 112         dev->base = (struct tah_regs __iomem *)ioremap(regs.start,
 113                                                sizeof(struct tah_regs));
 114         if (dev->base == NULL) {
 115                 printk(KERN_ERR "%pOF: Can't map device registers!\n", np);
 116                 goto err_free;
 117         }
 118
 119         platform_set_drvdata(ofdev, dev);
 120
 121         /* Initialize TAH and enable IPv4 checksum verification, no TSO yet */
 122         tah_reset(ofdev);
 123
 124         printk(KERN_INFO "TAH %pOF initialized\n", ofdev->dev.of_node);
 125         wmb();
 126
 127         return 0;
 128
 129  err_free:
 130         kfree(dev);
 131  err_gone:
 132         return rc;
 133 }
 134
 135 static int tah_remove(struct platform_device *ofdev)
 136 {
 137         struct tah_instance *dev = platform_get_drvdata(ofdev);
 138
 139         WARN_ON(dev->users != 0);
 140
 141         iounmap(dev->base);
 142         kfree(dev);
 143
 144         return 0;
 145 }
 146
 147 static const struct of_device_id tah_match[] =
 148 {
 149         {
 150                 .compatible     = "ibm,tah",
 151         },
 152         /* For backward compat with old DT */
 153         {
 154                 .type           = "tah",
 155         },
 156         {},
 157 };
 158
 159 static struct platform_driver tah_driver = {
 160         .driver = {
 161                 .name = "emac-tah",
 162                 .of_match_table = tah_match,
 163         },
 164         .probe = tah_probe,
 165         .remove = tah_remove,
 166 };
 167
 168 int __init tah_init(void)
 169 {
 170         return platform_driver_register(&tah_driver);
 171 }
 172
 173 void tah_exit(void)
 174 {
 175         platform_driver_unregister(&tah_driver);
 176 }