173 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * drivers/net/ethernet/ibm/emac/tah.c4 *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 25int 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 37void 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 46void 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 67int tah_get_regs_len(struct platform_device *ofdev)68{69 return sizeof(struct emac_ethtool_regs_subhdr) +70 sizeof(struct tah_regs);71}72 73void *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 one81 * zmii ? if yes, then we'll add a cell_index82 * like we do for emac83 */84 memcpy_fromio(regs, dev->base, sizeof(struct tah_regs));85 return regs + 1;86}87 88static 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 133static 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 143static 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 155static 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 164int __init tah_init(void)165{166 return platform_driver_register(&tah_driver);167}168 169void tah_exit(void)170{171 platform_driver_unregister(&tah_driver);172}173