xref: /linux/drivers/net/ethernet/ibm/emac/tah.c (revision 4413e16d9d21673bb5048a2e542f1aaa00015c2e)
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 
26 int __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 
38 void 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 
47 void 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 
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 = 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 
90 static 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 
138 static 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 
152 static 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 
164 static 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 
174 int __init tah_init(void)
175 {
176 	return platform_driver_register(&tah_driver);
177 }
178 
179 void tah_exit(void)
180 {
181 	platform_driver_unregister(&tah_driver);
182 }
183