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
tah_attach(struct platform_device * ofdev,int channel)27 int 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
tah_detach(struct platform_device * ofdev,int channel)39 void 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
tah_reset(struct platform_device * ofdev)48 void 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 "%pOF: reset timeout\n", ofdev->dev.of_node);
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
tah_get_regs_len(struct platform_device * ofdev)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
tah_dump_regs(struct platform_device * ofdev,void * buf)75 void *tah_dump_regs(struct platform_device *ofdev, void *buf)
76 {
77 struct tah_instance *dev = platform_get_drvdata(ofdev);
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
tah_probe(struct platform_device * ofdev)90 static int 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, ®s)) {
107 printk(KERN_ERR "%pOF: Can't get registers address\n", np);
108 goto err_free;
109 }
110
111 rc = -ENOMEM;
112 dev->base = (struct tah_regs __iomem *)ioremap(regs.start,
113 sizeof(struct tah_regs));
114 if (dev->base == NULL) {
115 printk(KERN_ERR "%pOF: Can't map device registers!\n", np);
116 goto err_free;
117 }
118
119 platform_set_drvdata(ofdev, dev);
120
121 /* Initialize TAH and enable IPv4 checksum verification, no TSO yet */
122 tah_reset(ofdev);
123
124 printk(KERN_INFO "TAH %pOF initialized\n", ofdev->dev.of_node);
125 wmb();
126
127 return 0;
128
129 err_free:
130 kfree(dev);
131 err_gone:
132 return rc;
133 }
134
tah_remove(struct platform_device * ofdev)135 static int tah_remove(struct platform_device *ofdev)
136 {
137 struct tah_instance *dev = platform_get_drvdata(ofdev);
138
139 WARN_ON(dev->users != 0);
140
141 iounmap(dev->base);
142 kfree(dev);
143
144 return 0;
145 }
146
147 static const struct of_device_id tah_match[] =
148 {
149 {
150 .compatible = "ibm,tah",
151 },
152 /* For backward compat with old DT */
153 {
154 .type = "tah",
155 },
156 {},
157 };
158
159 static struct platform_driver tah_driver = {
160 .driver = {
161 .name = "emac-tah",
162 .of_match_table = tah_match,
163 },
164 .probe = tah_probe,
165 .remove = tah_remove,
166 };
167
tah_init(void)168 int __init tah_init(void)
169 {
170 return platform_driver_register(&tah_driver);
171 }
172
tah_exit(void)173 void tah_exit(void)
174 {
175 platform_driver_unregister(&tah_driver);
176 }
177
