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/mod_devicetable.h>
  18 #include <linux/of_address.h>
  19 #include <linux/platform_device.h>
  20 #include <asm/io.h>
  21
  22 #include "emac.h"
  23 #include "core.h"
  24
  25 int tah_attach(struct platform_device *ofdev, int channel)
  26 {
  27         struct tah_instance *dev = platform_get_drvdata(ofdev);
  28
  29         mutex_lock(&dev->lock);
  30         /* Reset has been done at probe() time... nothing else to do for now */
  31         ++dev->users;
  32         mutex_unlock(&dev->lock);
  33
  34         return 0;
  35 }
  36
  37 void tah_detach(struct platform_device *ofdev, int channel)
  38 {
  39         struct tah_instance *dev = platform_get_drvdata(ofdev);
  40
  41         mutex_lock(&dev->lock);
  42         --dev->users;
  43         mutex_unlock(&dev->lock);
  44 }
  45
  46 void tah_reset(struct platform_device *ofdev)
  47 {
  48         struct tah_instance *dev = platform_get_drvdata(ofdev);
  49         struct tah_regs __iomem *p = dev->base;
  50         int n;
  51
  52         /* Reset TAH */
  53         out_be32(&p->mr, TAH_MR_SR);
  54         n = 100;
  55         while ((in_be32(&p->mr) & TAH_MR_SR) && n)
  56                 --n;
  57
  58         if (unlikely(!n))
  59                 printk(KERN_ERR "%pOF: reset timeout\n", ofdev->dev.of_node);
  60
  61         /* 10KB TAH TX FIFO accommodates the max MTU of 9000 */
  62         out_be32(&p->mr,
  63                  TAH_MR_CVR | TAH_MR_ST_768 | TAH_MR_TFS_10KB | TAH_MR_DTFP |
  64                  TAH_MR_DIG);
  65 }
  66
  67 int tah_get_regs_len(struct platform_device *ofdev)
  68 {
  69         return sizeof(struct emac_ethtool_regs_subhdr) +
  70                 sizeof(struct tah_regs);
  71 }
  72
  73 void *tah_dump_regs(struct platform_device *ofdev, void *buf)
  74 {
  75         struct tah_instance *dev = platform_get_drvdata(ofdev);
  76         struct emac_ethtool_regs_subhdr *hdr = buf;
  77         struct tah_regs *regs = (struct tah_regs *)(hdr + 1);
  78
  79         hdr->version = 0;
  80         hdr->index = 0; /* for now, are there chips with more than one
  81                          * zmii ? if yes, then we'll add a cell_index
  82                          * like we do for emac
  83                          */
  84         memcpy_fromio(regs, dev->base, sizeof(struct tah_regs));
  85         return regs + 1;
  86 }
  87
  88 static int tah_probe(struct platform_device *ofdev)
  89 {
  90         struct tah_instance *dev;
  91         int err;
  92
  93         dev = devm_kzalloc(&ofdev->dev, sizeof(struct tah_instance),
  94                            GFP_KERNEL);
  95         if (!dev)
  96                 return -ENOMEM;
  97
  98         err = devm_mutex_init(&ofdev->dev, &dev->lock);
  99         if (err)
 100                 return err;
 101
 102         dev->ofdev = ofdev;
 103
 104         dev->base = devm_platform_ioremap_resource(ofdev, 0);
 105         if (IS_ERR(dev->base)) {
 106                 dev_err(&ofdev->dev, "can't map device registers");
 107                 return PTR_ERR(dev->base);
 108         }
 109
 110         platform_set_drvdata(ofdev, dev);
 111
 112         /* Initialize TAH and enable IPv4 checksum verification, no TSO yet */
 113         tah_reset(ofdev);
 114
 115         printk(KERN_INFO "TAH %pOF initialized\n", ofdev->dev.of_node);
 116         wmb();
 117
 118         return 0;
 119 }
 120
 121 static const struct of_device_id tah_match[] =
 122 {
 123         {
 124                 .compatible     = "ibm,tah",
 125         },
 126         /* For backward compat with old DT */
 127         {
 128                 .type           = "tah",
 129         },
 130         {},
 131 };
 132
 133 static struct platform_driver tah_driver = {
 134         .driver = {
 135                 .name = "emac-tah",
 136                 .of_match_table = tah_match,
 137         },
 138         .probe = tah_probe,
 139 };
 140
 141 int __init tah_init(void)
 142 {
 143         return platform_driver_register(&tah_driver);
 144 }
 145
 146 void tah_exit(void)
 147 {
 148         platform_driver_unregister(&tah_driver);
 149 }