xref: /openbmc/linux/drivers/net/ethernet/ibm/emac/tah.c (revision 3d40aed8)
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/mod_devicetable.h>
18 #include <linux/of_address.h>
19 #include <linux/platform_device.h>
20 #include <asm/io.h>
21 
22 #include "emac.h"
23 #include "core.h"
24 
tah_attach(struct platform_device * ofdev,int channel)25 int tah_attach(struct platform_device *ofdev, int channel)
26 {
27 	struct tah_instance *dev = platform_get_drvdata(ofdev);
28 
29 	mutex_lock(&dev->lock);
30 	/* Reset has been done at probe() time... nothing else to do for now */
31 	++dev->users;
32 	mutex_unlock(&dev->lock);
33 
34 	return 0;
35 }
36 
tah_detach(struct platform_device * ofdev,int channel)37 void tah_detach(struct platform_device *ofdev, int channel)
38 {
39 	struct tah_instance *dev = platform_get_drvdata(ofdev);
40 
41 	mutex_lock(&dev->lock);
42 	--dev->users;
43 	mutex_unlock(&dev->lock);
44 }
45 
tah_reset(struct platform_device * ofdev)46 void tah_reset(struct platform_device *ofdev)
47 {
48 	struct tah_instance *dev = platform_get_drvdata(ofdev);
49 	struct tah_regs __iomem *p = dev->base;
50 	int n;
51 
52 	/* Reset TAH */
53 	out_be32(&p->mr, TAH_MR_SR);
54 	n = 100;
55 	while ((in_be32(&p->mr) & TAH_MR_SR) && n)
56 		--n;
57 
58 	if (unlikely(!n))
59 		printk(KERN_ERR "%pOF: reset timeout\n", ofdev->dev.of_node);
60 
61 	/* 10KB TAH TX FIFO accommodates the max MTU of 9000 */
62 	out_be32(&p->mr,
63 		 TAH_MR_CVR | TAH_MR_ST_768 | TAH_MR_TFS_10KB | TAH_MR_DTFP |
64 		 TAH_MR_DIG);
65 }
66 
tah_get_regs_len(struct platform_device * ofdev)67 int tah_get_regs_len(struct platform_device *ofdev)
68 {
69 	return sizeof(struct emac_ethtool_regs_subhdr) +
70 		sizeof(struct tah_regs);
71 }
72 
tah_dump_regs(struct platform_device * ofdev,void * buf)73 void *tah_dump_regs(struct platform_device *ofdev, void *buf)
74 {
75 	struct tah_instance *dev = platform_get_drvdata(ofdev);
76 	struct emac_ethtool_regs_subhdr *hdr = buf;
77 	struct tah_regs *regs = (struct tah_regs *)(hdr + 1);
78 
79 	hdr->version = 0;
80 	hdr->index = 0; /* for now, are there chips with more than one
81 			 * zmii ? if yes, then we'll add a cell_index
82 			 * like we do for emac
83 			 */
84 	memcpy_fromio(regs, dev->base, sizeof(struct tah_regs));
85 	return regs + 1;
86 }
87 
tah_probe(struct platform_device * ofdev)88 static int tah_probe(struct platform_device *ofdev)
89 {
90 	struct device_node *np = ofdev->dev.of_node;
91 	struct tah_instance *dev;
92 	struct resource regs;
93 	int rc;
94 
95 	rc = -ENOMEM;
96 	dev = kzalloc(sizeof(struct tah_instance), GFP_KERNEL);
97 	if (dev == NULL)
98 		goto err_gone;
99 
100 	mutex_init(&dev->lock);
101 	dev->ofdev = ofdev;
102 
103 	rc = -ENXIO;
104 	if (of_address_to_resource(np, 0, &regs)) {
105 		printk(KERN_ERR "%pOF: Can't get registers address\n", np);
106 		goto err_free;
107 	}
108 
109 	rc = -ENOMEM;
110 	dev->base = (struct tah_regs __iomem *)ioremap(regs.start,
111 					       sizeof(struct tah_regs));
112 	if (dev->base == NULL) {
113 		printk(KERN_ERR "%pOF: Can't map device registers!\n", np);
114 		goto err_free;
115 	}
116 
117 	platform_set_drvdata(ofdev, dev);
118 
119 	/* Initialize TAH and enable IPv4 checksum verification, no TSO yet */
120 	tah_reset(ofdev);
121 
122 	printk(KERN_INFO "TAH %pOF initialized\n", ofdev->dev.of_node);
123 	wmb();
124 
125 	return 0;
126 
127  err_free:
128 	kfree(dev);
129  err_gone:
130 	return rc;
131 }
132 
tah_remove(struct platform_device * ofdev)133 static int tah_remove(struct platform_device *ofdev)
134 {
135 	struct tah_instance *dev = platform_get_drvdata(ofdev);
136 
137 	WARN_ON(dev->users != 0);
138 
139 	iounmap(dev->base);
140 	kfree(dev);
141 
142 	return 0;
143 }
144 
145 static const struct of_device_id tah_match[] =
146 {
147 	{
148 		.compatible	= "ibm,tah",
149 	},
150 	/* For backward compat with old DT */
151 	{
152 		.type		= "tah",
153 	},
154 	{},
155 };
156 
157 static struct platform_driver tah_driver = {
158 	.driver = {
159 		.name = "emac-tah",
160 		.of_match_table = tah_match,
161 	},
162 	.probe = tah_probe,
163 	.remove = tah_remove,
164 };
165 
tah_init(void)166 int __init tah_init(void)
167 {
168 	return platform_driver_register(&tah_driver);
169 }
170 
tah_exit(void)171 void tah_exit(void)
172 {
173 	platform_driver_unregister(&tah_driver);
174 }
175