drivers/mtd/maps/ixp2000.c

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