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
27int 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
39void 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
48void 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
70int tah_get_regs_len(struct platform_device *ofdev)
71{
72	return sizeof(struct emac_ethtool_regs_subhdr) +
73		sizeof(struct tah_regs);
74}
75
76void *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
91static 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
139static 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
151static const 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
163static struct platform_driver tah_driver = {
164	.driver = {
165		.name = "emac-tah",
166		.of_match_table = tah_match,
167	},
168	.probe = tah_probe,
169	.remove = tah_remove,
170};
171
172int __init tah_init(void)
173{
174	return platform_driver_register(&tah_driver);
175}
176
177void tah_exit(void)
178{
179	platform_driver_unregister(&tah_driver);
180}
181