xref: /openbmc/linux/drivers/net/ethernet/ibm/emac/tah.c (revision da733563be5a9da26fe81d9f007262d00b846e22)
1 /*
2  * drivers/net/ibm_newemac/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 		printk(KERN_ERR "%s: could not allocate TAH device!\n",
101 		       np->full_name);
102 		goto err_gone;
103 	}
104 
105 	mutex_init(&dev->lock);
106 	dev->ofdev = ofdev;
107 
108 	rc = -ENXIO;
109 	if (of_address_to_resource(np, 0, &regs)) {
110 		printk(KERN_ERR "%s: Can't get registers address\n",
111 		       np->full_name);
112 		goto err_free;
113 	}
114 
115 	rc = -ENOMEM;
116 	dev->base = (struct tah_regs __iomem *)ioremap(regs.start,
117 					       sizeof(struct tah_regs));
118 	if (dev->base == NULL) {
119 		printk(KERN_ERR "%s: Can't map device registers!\n",
120 		       np->full_name);
121 		goto err_free;
122 	}
123 
124 	dev_set_drvdata(&ofdev->dev, dev);
125 
126 	/* Initialize TAH and enable IPv4 checksum verification, no TSO yet */
127 	tah_reset(ofdev);
128 
129 	printk(KERN_INFO
130 	       "TAH %s initialized\n", ofdev->dev.of_node->full_name);
131 	wmb();
132 
133 	return 0;
134 
135  err_free:
136 	kfree(dev);
137  err_gone:
138 	return rc;
139 }
140 
141 static int __devexit tah_remove(struct platform_device *ofdev)
142 {
143 	struct tah_instance *dev = dev_get_drvdata(&ofdev->dev);
144 
145 	dev_set_drvdata(&ofdev->dev, NULL);
146 
147 	WARN_ON(dev->users != 0);
148 
149 	iounmap(dev->base);
150 	kfree(dev);
151 
152 	return 0;
153 }
154 
155 static struct of_device_id tah_match[] =
156 {
157 	{
158 		.compatible	= "ibm,tah",
159 	},
160 	/* For backward compat with old DT */
161 	{
162 		.type		= "tah",
163 	},
164 	{},
165 };
166 
167 static struct platform_driver tah_driver = {
168 	.driver = {
169 		.name = "emac-tah",
170 		.owner = THIS_MODULE,
171 		.of_match_table = tah_match,
172 	},
173 	.probe = tah_probe,
174 	.remove = tah_remove,
175 };
176 
177 int __init tah_init(void)
178 {
179 	return platform_driver_register(&tah_driver);
180 }
181 
182 void tah_exit(void)
183 {
184 	platform_driver_unregister(&tah_driver);
185 }
186