1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * drivers/net/ethernet/ibm/emac/tah.c
4 *
5 * Driver for PowerPC 4xx on-chip ethernet controller, TAH support.
6 *
7 * Copyright 2007 Benjamin Herrenschmidt, IBM Corp.
8 * <benh@kernel.crashing.org>
9 *
10 * Based on the arch/ppc version of the driver:
11 *
12 * Copyright 2004 MontaVista Software, Inc.
13 * Matt Porter <mporter@kernel.crashing.org>
14 *
15 * Copyright (c) 2005 Eugene Surovegin <ebs@ebshome.net>
16 */
17 #include <linux/of_address.h>
18 #include <asm/io.h>
19
20 #include "emac.h"
21 #include "core.h"
22
tah_attach(struct platform_device * ofdev,int channel)23 int tah_attach(struct platform_device *ofdev, int channel)
24 {
25 struct tah_instance *dev = platform_get_drvdata(ofdev);
26
27 mutex_lock(&dev->lock);
28 /* Reset has been done at probe() time... nothing else to do for now */
29 ++dev->users;
30 mutex_unlock(&dev->lock);
31
32 return 0;
33 }
34
tah_detach(struct platform_device * ofdev,int channel)35 void tah_detach(struct platform_device *ofdev, int channel)
36 {
37 struct tah_instance *dev = platform_get_drvdata(ofdev);
38
39 mutex_lock(&dev->lock);
40 --dev->users;
41 mutex_unlock(&dev->lock);
42 }
43
tah_reset(struct platform_device * ofdev)44 void tah_reset(struct platform_device *ofdev)
45 {
46 struct tah_instance *dev = platform_get_drvdata(ofdev);
47 struct tah_regs __iomem *p = dev->base;
48 int n;
49
50 /* Reset TAH */
51 out_be32(&p->mr, TAH_MR_SR);
52 n = 100;
53 while ((in_be32(&p->mr) & TAH_MR_SR) && n)
54 --n;
55
56 if (unlikely(!n))
57 printk(KERN_ERR "%pOF: reset timeout\n", ofdev->dev.of_node);
58
59 /* 10KB TAH TX FIFO accommodates the max MTU of 9000 */
60 out_be32(&p->mr,
61 TAH_MR_CVR | TAH_MR_ST_768 | TAH_MR_TFS_10KB | TAH_MR_DTFP |
62 TAH_MR_DIG);
63 }
64
tah_get_regs_len(struct platform_device * ofdev)65 int tah_get_regs_len(struct platform_device *ofdev)
66 {
67 return sizeof(struct emac_ethtool_regs_subhdr) +
68 sizeof(struct tah_regs);
69 }
70
tah_dump_regs(struct platform_device * ofdev,void * buf)71 void *tah_dump_regs(struct platform_device *ofdev, void *buf)
72 {
73 struct tah_instance *dev = platform_get_drvdata(ofdev);
74 struct emac_ethtool_regs_subhdr *hdr = buf;
75 struct tah_regs *regs = (struct tah_regs *)(hdr + 1);
76
77 hdr->version = 0;
78 hdr->index = 0; /* for now, are there chips with more than one
79 * zmii ? if yes, then we'll add a cell_index
80 * like we do for emac
81 */
82 memcpy_fromio(regs, dev->base, sizeof(struct tah_regs));
83 return regs + 1;
84 }
85
tah_probe(struct platform_device * ofdev)86 static int tah_probe(struct platform_device *ofdev)
87 {
88 struct device_node *np = ofdev->dev.of_node;
89 struct tah_instance *dev;
90 struct resource regs;
91 int rc;
92
93 rc = -ENOMEM;
94 dev = kzalloc(sizeof(struct tah_instance), GFP_KERNEL);
95 if (dev == NULL)
96 goto err_gone;
97
98 mutex_init(&dev->lock);
99 dev->ofdev = ofdev;
100
101 rc = -ENXIO;
102 if (of_address_to_resource(np, 0, ®s)) {
103 printk(KERN_ERR "%pOF: Can't get registers address\n", np);
104 goto err_free;
105 }
106
107 rc = -ENOMEM;
108 dev->base = (struct tah_regs __iomem *)ioremap(regs.start,
109 sizeof(struct tah_regs));
110 if (dev->base == NULL) {
111 printk(KERN_ERR "%pOF: Can't map device registers!\n", np);
112 goto err_free;
113 }
114
115 platform_set_drvdata(ofdev, dev);
116
117 /* Initialize TAH and enable IPv4 checksum verification, no TSO yet */
118 tah_reset(ofdev);
119
120 printk(KERN_INFO "TAH %pOF initialized\n", ofdev->dev.of_node);
121 wmb();
122
123 return 0;
124
125 err_free:
126 kfree(dev);
127 err_gone:
128 return rc;
129 }
130
tah_remove(struct platform_device * ofdev)131 static int tah_remove(struct platform_device *ofdev)
132 {
133 struct tah_instance *dev = platform_get_drvdata(ofdev);
134
135 WARN_ON(dev->users != 0);
136
137 iounmap(dev->base);
138 kfree(dev);
139
140 return 0;
141 }
142
143 static const struct of_device_id tah_match[] =
144 {
145 {
146 .compatible = "ibm,tah",
147 },
148 /* For backward compat with old DT */
149 {
150 .type = "tah",
151 },
152 {},
153 };
154
155 static struct platform_driver tah_driver = {
156 .driver = {
157 .name = "emac-tah",
158 .of_match_table = tah_match,
159 },
160 .probe = tah_probe,
161 .remove = tah_remove,
162 };
163
tah_init(void)164 int __init tah_init(void)
165 {
166 return platform_driver_register(&tah_driver);
167 }
168
tah_exit(void)169 void tah_exit(void)
170 {
171 platform_driver_unregister(&tah_driver);
172 }
173