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
 26int __devinit tah_attach(struct platform_device *ofdev, int channel)
 27{
 28	struct tah_instance *dev = dev_get_drvdata(&ofdev->dev);
 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
 38void tah_detach(struct platform_device *ofdev, int channel)
 39{
 40	struct tah_instance *dev = dev_get_drvdata(&ofdev->dev);
 41
 42	mutex_lock(&dev->lock);
 43	--dev->users;
 44	mutex_unlock(&dev->lock);
 45}
 46
 47void tah_reset(struct platform_device *ofdev)
 48{
 49	struct tah_instance *dev = dev_get_drvdata(&ofdev->dev);
 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
 69int tah_get_regs_len(struct platform_device *ofdev)
 70{
 71	return sizeof(struct emac_ethtool_regs_subhdr) +
 72		sizeof(struct tah_regs);
 73}
 74
 75void *tah_dump_regs(struct platform_device *ofdev, void *buf)
 76{
 77	struct tah_instance *dev = dev_get_drvdata(&ofdev->dev);
 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
 90static int __devinit 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	dev_set_drvdata(&ofdev->dev, 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
138static int __devexit tah_remove(struct platform_device *ofdev)
139{
140	struct tah_instance *dev = dev_get_drvdata(&ofdev->dev);
141
142	dev_set_drvdata(&ofdev->dev, NULL);
143
144	WARN_ON(dev->users != 0);
145
146	iounmap(dev->base);
147	kfree(dev);
148
149	return 0;
150}
151
152static struct of_device_id tah_match[] =
153{
154	{
155		.compatible	= "ibm,tah",
156	},
157	/* For backward compat with old DT */
158	{
159		.type		= "tah",
160	},
161	{},
162};
163
164static struct platform_driver tah_driver = {
165	.driver = {
166		.name = "emac-tah",
167		.owner = THIS_MODULE,
168		.of_match_table = tah_match,
169	},
170	.probe = tah_probe,
171	.remove = tah_remove,
172};
173
174int __init tah_init(void)
175{
176	return platform_driver_register(&tah_driver);
177}
178
179void tah_exit(void)
180{
181	platform_driver_unregister(&tah_driver);
182}