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   1 /*
   2  * $Id: ixp2000.c,v 1.9 2005/11/07 11:14:27 gleixner Exp $
   3  *
   4  * drivers/mtd/maps/ixp2000.c
   5  *
   6  * Mapping for the Intel XScale IXP2000 based systems
   7  *
   8  * Copyright (C) 2002 Intel Corp.
   9  * Copyright (C) 2003-2004 MontaVista Software, Inc.
  10  *
  11  * Original Author: Naeem M Afzal <naeem.m.afzal@intel.com>
  12  * Maintainer: Deepak Saxena <dsaxena@plexity.net>
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License version 2 as
  16  * published by the Free Software Foundation.
  17  *
  18  */
  19
  20 #include <linux/module.h>
  21 #include <linux/types.h>
  22 #include <linux/init.h>
  23 #include <linux/kernel.h>
  24 #include <linux/string.h>
  25 #include <linux/slab.h>
  26 #include <linux/ioport.h>
  27 #include <linux/device.h>
  28 #include <linux/platform_device.h>
  29
  30 #include <linux/mtd/mtd.h>
  31 #include <linux/mtd/map.h>
  32 #include <linux/mtd/partitions.h>
  33
  34 #include <asm/io.h>
  35 #include <asm/hardware.h>
  36 #include <asm/mach/flash.h>
  37
  38 #include <linux/reboot.h>
  39
  40 struct ixp2000_flash_info {
  41         struct          mtd_info *mtd;
  42         struct          map_info map;
  43         struct          mtd_partition *partitions;
  44         struct          resource *res;
  45         int             nr_banks;
  46 };
  47
  48 static inline unsigned long flash_bank_setup(struct map_info *map, unsigned long ofs)
  49 {
  50         unsigned long (*set_bank)(unsigned long) =
  51                 (unsigned long(*)(unsigned long))map->map_priv_2;
  52
  53         return (set_bank ? set_bank(ofs) : ofs);
  54 }
  55
  56 #ifdef __ARMEB__
  57 /*
  58  * Rev A0 and A1 of IXP2400 silicon have a broken addressing unit which
  59  * causes the lower address bits to be XORed with 0x11 on 8 bit accesses
  60  * and XORed with 0x10 on 16 bit accesses. See the spec update, erratum 44.
  61  */
  62 static int erratum44_workaround = 0;
  63
  64 static inline unsigned long address_fix8_write(unsigned long addr)
  65 {
  66         if (erratum44_workaround) {
  67                 return (addr ^ 3);
  68         }
  69         return addr;
  70 }
  71 #else
  72
  73 #define address_fix8_write(x)   (x)
  74 #endif
  75
  76 static map_word ixp2000_flash_read8(struct map_info *map, unsigned long ofs)
  77 {
  78         map_word val;
  79
  80         val.x[0] =  *((u8 *)(map->map_priv_1 + flash_bank_setup(map, ofs)));
  81         return val;
  82 }
  83
  84 /*
  85  * We can't use the standard memcpy due to the broken SlowPort
  86  * address translation on rev A0 and A1 silicon and the fact that
  87  * we have banked flash.
  88  */
  89 static void ixp2000_flash_copy_from(struct map_info *map, void *to,
  90                               unsigned long from, ssize_t len)
  91 {
  92         from = flash_bank_setup(map, from);
  93         while(len--)
  94                 *(__u8 *) to++ = *(__u8 *)(map->map_priv_1 + from++);
  95 }
  96
  97 static void ixp2000_flash_write8(struct map_info *map, map_word d, unsigned long ofs)
  98 {
  99         *(__u8 *) (address_fix8_write(map->map_priv_1 +
 100                                       flash_bank_setup(map, ofs))) = d.x[0];
 101 }
 102
 103 static void ixp2000_flash_copy_to(struct map_info *map, unsigned long to,
 104                             const void *from, ssize_t len)
 105 {
 106         to = flash_bank_setup(map, to);
 107         while(len--) {
 108                 unsigned long tmp = address_fix8_write(map->map_priv_1 + to++);
 109                 *(__u8 *)(tmp) = *(__u8 *)(from++);
 110         }
 111 }
 112
 113
 114 static int ixp2000_flash_remove(struct device *_dev)
 115 {
 116         struct platform_device *dev = to_platform_device(_dev);
 117         struct flash_platform_data *plat = dev->dev.platform_data;
 118         struct ixp2000_flash_info *info = dev_get_drvdata(&dev->dev);
 119
 120         dev_set_drvdata(&dev->dev, NULL);
 121
 122         if(!info)
 123                 return 0;
 124
 125         if (info->mtd) {
 126                 del_mtd_partitions(info->mtd);
 127                 map_destroy(info->mtd);
 128         }
 129         if (info->map.map_priv_1)
 130                 iounmap((void *) info->map.map_priv_1);
 131
 132         kfree(info->partitions);
 133
 134         if (info->res) {
 135                 release_resource(info->res);
 136                 kfree(info->res);
 137         }
 138
 139         if (plat->exit)
 140                 plat->exit();
 141
 142         return 0;
 143 }
 144
 145
 146 static int ixp2000_flash_probe(struct device *_dev)
 147 {
 148         static const char *probes[] = { "RedBoot", "cmdlinepart", NULL };
 149         struct platform_device *dev = to_platform_device(_dev);
 150         struct ixp2000_flash_data *ixp_data = dev->dev.platform_data;
 151         struct flash_platform_data *plat;
 152         struct ixp2000_flash_info *info;
 153         unsigned long window_size;
 154         int err = -1;
 155
 156         if (!ixp_data)
 157                 return -ENODEV;
 158
 159         plat = ixp_data->platform_data;
 160         if (!plat)
 161                 return -ENODEV;
 162
 163         window_size = dev->resource->end - dev->resource->start + 1;
 164         dev_info(_dev, "Probe of IXP2000 flash(%d banks x %dMiB)\n",
 165                         ixp_data->nr_banks, ((u32)window_size >> 20));
 166
 167         if (plat->width != 1) {
 168                 dev_err(_dev, "IXP2000 MTD map only supports 8-bit mode, asking for %d\n",
 169                                 plat->width * 8);
 170                 return -EIO;
 171         }
 172
 173         info = kmalloc(sizeof(struct ixp2000_flash_info), GFP_KERNEL);
 174         if(!info) {
 175                 err = -ENOMEM;
 176                 goto Error;
 177         }
 178         memzero(info, sizeof(struct ixp2000_flash_info));
 179
 180         dev_set_drvdata(&dev->dev, info);
 181
 182         /*
 183          * Tell the MTD layer we're not 1:1 mapped so that it does
 184          * not attempt to do a direct access on us.
 185          */
 186         info->map.phys = NO_XIP;
 187
 188         info->nr_banks = ixp_data->nr_banks;
 189         info->map.size = ixp_data->nr_banks * window_size;
 190         info->map.bankwidth = 1;
 191
 192         /*
 193          * map_priv_2 is used to store a ptr to to the bank_setup routine
 194          */
 195         info->map.map_priv_2 = (unsigned long) ixp_data->bank_setup;
 196
 197         info->map.name = dev->dev.bus_id;
 198         info->map.read = ixp2000_flash_read8;
 199         info->map.write = ixp2000_flash_write8;
 200         info->map.copy_from = ixp2000_flash_copy_from;
 201         info->map.copy_to = ixp2000_flash_copy_to;
 202
 203         info->res = request_mem_region(dev->resource->start,
 204                         dev->resource->end - dev->resource->start + 1,
 205                         dev->dev.bus_id);
 206         if (!info->res) {
 207                 dev_err(_dev, "Could not reserve memory region\n");
 208                 err = -ENOMEM;
 209                 goto Error;
 210         }
 211
 212         info->map.map_priv_1 = (unsigned long) ioremap(dev->resource->start,
 213                                 dev->resource->end - dev->resource->start + 1);
 214         if (!info->map.map_priv_1) {
 215                 dev_err(_dev, "Failed to ioremap flash region\n");
 216                 err = -EIO;
 217                 goto Error;
 218         }
 219
 220 #if defined(__ARMEB__)
 221         /*
 222          * Enable erratum 44 workaround for NPUs with broken slowport
 223          */
 224
 225         erratum44_workaround = ixp2000_has_broken_slowport();
 226         dev_info(_dev, "Erratum 44 workaround %s\n",
 227                erratum44_workaround ? "enabled" : "disabled");
 228 #endif
 229
 230         info->mtd = do_map_probe(plat->map_name, &info->map);
 231         if (!info->mtd) {
 232                 dev_err(_dev, "map_probe failed\n");
 233                 err = -ENXIO;
 234                 goto Error;
 235         }
 236         info->mtd->owner = THIS_MODULE;
 237
 238         err = parse_mtd_partitions(info->mtd, probes, &info->partitions, 0);
 239         if (err > 0) {
 240                 err = add_mtd_partitions(info->mtd, info->partitions, err);
 241                 if(err)
 242                         dev_err(_dev, "Could not parse partitions\n");
 243         }
 244
 245         if (err)
 246                 goto Error;
 247
 248         return 0;
 249
 250 Error:
 251         ixp2000_flash_remove(_dev);
 252         return err;
 253 }
 254
 255 static struct device_driver ixp2000_flash_driver = {
 256         .name           = "IXP2000-Flash",
 257         .bus            = &platform_bus_type,
 258         .probe          = &ixp2000_flash_probe,
 259         .remove         = &ixp2000_flash_remove
 260 };
 261
 262 static int __init ixp2000_flash_init(void)
 263 {
 264         return driver_register(&ixp2000_flash_driver);
 265 }
 266
 267 static void __exit ixp2000_flash_exit(void)
 268 {
 269         driver_unregister(&ixp2000_flash_driver);
 270 }
 271
 272 module_init(ixp2000_flash_init);
 273 module_exit(ixp2000_flash_exit);
 274 MODULE_LICENSE("GPL");
 275 MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>");
 276