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 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 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 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 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 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 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 } 130 131 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 }; 163 164 int __init tah_init(void) 165 { 166 return platform_driver_register(&tah_driver); 167 } 168 169 void tah_exit(void) 170 { 171 platform_driver_unregister(&tah_driver); 172 } 173