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 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 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 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 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 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 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, ®s)) { 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 } 132 133 static void 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 } 142 143 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_new = 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