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 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 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 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 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 = 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 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 } 134 135 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 }; 167 168 int __init tah_init(void) 169 { 170 return platform_driver_register(&tah_driver); 171 } 172 173 void tah_exit(void) 174 { 175 platform_driver_unregister(&tah_driver); 176 } 177