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

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * drivers/net/ethernet/ibm/emac/tah.c
   4  *
   5  * Driver for PowerPC 4xx on-chip ethernet controller, TAH support.
   6  *
   7  * Copyright 2007 Benjamin Herrenschmidt, IBM Corp.
   8  *                <benh@kernel.crashing.org>
   9  *
  10  * Based on the arch/ppc version of the driver:
  11  *
  12  * Copyright 2004 MontaVista Software, Inc.
  13  * Matt Porter <mporter@kernel.crashing.org>
  14  *
  15  * Copyright (c) 2005 Eugene Surovegin <ebs@ebshome.net>
  16  */
  17 #include <linux/of_address.h>
  18 #include <asm/io.h>
  19
  20 #include "emac.h"
  21 #include "core.h"
  22
  23 int tah_attach(struct platform_device *ofdev, int channel)
  24 {
  25         struct tah_instance *dev = platform_get_drvdata(ofdev);
  26
  27         mutex_lock(&dev->lock);
  28         /* Reset has been done at probe() time... nothing else to do for now */
  29         ++dev->users;
  30         mutex_unlock(&dev->lock);
  31
  32         return 0;
  33 }
  34
  35 void tah_detach(struct platform_device *ofdev, int channel)
  36 {
  37         struct tah_instance *dev = platform_get_drvdata(ofdev);
  38
  39         mutex_lock(&dev->lock);
  40         --dev->users;
  41         mutex_unlock(&dev->lock);
  42 }
  43
  44 void tah_reset(struct platform_device *ofdev)
  45 {
  46         struct tah_instance *dev = platform_get_drvdata(ofdev);
  47         struct tah_regs __iomem *p = dev->base;
  48         int n;
  49
  50         /* Reset TAH */
  51         out_be32(&p->mr, TAH_MR_SR);
  52         n = 100;
  53         while ((in_be32(&p->mr) & TAH_MR_SR) && n)
  54                 --n;
  55
  56         if (unlikely(!n))
  57                 printk(KERN_ERR "%pOF: reset timeout\n", ofdev->dev.of_node);
  58
  59         /* 10KB TAH TX FIFO accommodates the max MTU of 9000 */
  60         out_be32(&p->mr,
  61                  TAH_MR_CVR | TAH_MR_ST_768 | TAH_MR_TFS_10KB | TAH_MR_DTFP |
  62                  TAH_MR_DIG);
  63 }
  64
  65 int tah_get_regs_len(struct platform_device *ofdev)
  66 {
  67         return sizeof(struct emac_ethtool_regs_subhdr) +
  68                 sizeof(struct tah_regs);
  69 }
  70
  71 void *tah_dump_regs(struct platform_device *ofdev, void *buf)
  72 {
  73         struct tah_instance *dev = platform_get_drvdata(ofdev);
  74         struct emac_ethtool_regs_subhdr *hdr = buf;
  75         struct tah_regs *regs = (struct tah_regs *)(hdr + 1);
  76
  77         hdr->version = 0;
  78         hdr->index = 0; /* for now, are there chips with more than one
  79                          * zmii ? if yes, then we'll add a cell_index
  80                          * like we do for emac
  81                          */
  82         memcpy_fromio(regs, dev->base, sizeof(struct tah_regs));
  83         return regs + 1;
  84 }
  85
  86 static int tah_probe(struct platform_device *ofdev)
  87 {
  88         struct device_node *np = ofdev->dev.of_node;
  89         struct tah_instance *dev;
  90         struct resource regs;
  91         int rc;
  92
  93         rc = -ENOMEM;
  94         dev = kzalloc(sizeof(struct tah_instance), GFP_KERNEL);
  95         if (dev == NULL)
  96                 goto err_gone;
  97
  98         mutex_init(&dev->lock);
  99         dev->ofdev = ofdev;
 100
 101         rc = -ENXIO;
 102         if (of_address_to_resource(np, 0, &regs)) {
 103                 printk(KERN_ERR "%pOF: Can't get registers address\n", np);
 104                 goto err_free;
 105         }
 106
 107         rc = -ENOMEM;
 108         dev->base = (struct tah_regs __iomem *)ioremap(regs.start,
 109                                                sizeof(struct tah_regs));
 110         if (dev->base == NULL) {
 111                 printk(KERN_ERR "%pOF: Can't map device registers!\n", np);
 112                 goto err_free;
 113         }
 114
 115         platform_set_drvdata(ofdev, dev);
 116
 117         /* Initialize TAH and enable IPv4 checksum verification, no TSO yet */
 118         tah_reset(ofdev);
 119
 120         printk(KERN_INFO "TAH %pOF initialized\n", ofdev->dev.of_node);
 121         wmb();
 122
 123         return 0;
 124
 125  err_free:
 126         kfree(dev);
 127  err_gone:
 128         return rc;
 129 }
 130
 131 static int tah_remove(struct platform_device *ofdev)
 132 {
 133         struct tah_instance *dev = platform_get_drvdata(ofdev);
 134
 135         WARN_ON(dev->users != 0);
 136
 137         iounmap(dev->base);
 138         kfree(dev);
 139
 140         return 0;
 141 }
 142
 143 static const struct of_device_id tah_match[] =
 144 {
 145         {
 146                 .compatible     = "ibm,tah",
 147         },
 148         /* For backward compat with old DT */
 149         {
 150                 .type           = "tah",
 151         },
 152         {},
 153 };
 154
 155 static struct platform_driver tah_driver = {
 156         .driver = {
 157                 .name = "emac-tah",
 158                 .of_match_table = tah_match,
 159         },
 160         .probe = tah_probe,
 161         .remove = tah_remove,
 162 };
 163
 164 int __init tah_init(void)
 165 {
 166         return platform_driver_register(&tah_driver);
 167 }
 168
 169 void tah_exit(void)
 170 {
 171         platform_driver_unregister(&tah_driver);
 172 }