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          resource *res;
  42 };
  43
  44 static inline unsigned long flash_bank_setup(struct map_info *map, unsigned long ofs)
  45 {
  46         unsigned long (*set_bank)(unsigned long) =
  47                 (unsigned long(*)(unsigned long))map->map_priv_2;
  48
  49         return (set_bank ? set_bank(ofs) : ofs);
  50 }
  51
  52 #ifdef __ARMEB__
  53 /*
  54  * Rev A0 and A1 of IXP2400 silicon have a broken addressing unit which
  55  * causes the lower address bits to be XORed with 0x11 on 8 bit accesses
  56  * and XORed with 0x10 on 16 bit accesses. See the spec update, erratum 44.
  57  */
  58 static int erratum44_workaround = 0;
  59
  60 static inline unsigned long address_fix8_write(unsigned long addr)
  61 {
  62         if (erratum44_workaround) {
  63                 return (addr ^ 3);
  64         }
  65         return addr;
  66 }
  67 #else
  68
  69 #define address_fix8_write(x)   (x)
  70 #endif
  71
  72 static map_word ixp2000_flash_read8(struct map_info *map, unsigned long ofs)
  73 {
  74         map_word val;
  75
  76         val.x[0] =  *((u8 *)(map->map_priv_1 + flash_bank_setup(map, ofs)));
  77         return val;
  78 }
  79
  80 /*
  81  * We can't use the standard memcpy due to the broken SlowPort
  82  * address translation on rev A0 and A1 silicon and the fact that
  83  * we have banked flash.
  84  */
  85 static void ixp2000_flash_copy_from(struct map_info *map, void *to,
  86                               unsigned long from, ssize_t len)
  87 {
  88         from = flash_bank_setup(map, from);
  89         while(len--)
  90                 *(__u8 *) to++ = *(__u8 *)(map->map_priv_1 + from++);
  91 }
  92
  93 static void ixp2000_flash_write8(struct map_info *map, map_word d, unsigned long ofs)
  94 {
  95         *(__u8 *) (address_fix8_write(map->map_priv_1 +
  96                                       flash_bank_setup(map, ofs))) = d.x[0];
  97 }
  98
  99 static void ixp2000_flash_copy_to(struct map_info *map, unsigned long to,
 100                             const void *from, ssize_t len)
 101 {
 102         to = flash_bank_setup(map, to);
 103         while(len--) {
 104                 unsigned long tmp = address_fix8_write(map->map_priv_1 + to++);
 105                 *(__u8 *)(tmp) = *(__u8 *)(from++);
 106         }
 107 }
 108
 109
 110 static int ixp2000_flash_remove(struct platform_device *dev)
 111 {
 112         struct flash_platform_data *plat = dev->dev.platform_data;
 113         struct ixp2000_flash_info *info = platform_get_drvdata(dev);
 114
 115         platform_set_drvdata(dev, NULL);
 116
 117         if(!info)
 118                 return 0;
 119
 120         if (info->mtd) {
 121                 mtd_device_unregister(info->mtd);
 122                 map_destroy(info->mtd);
 123         }
 124         if (info->map.map_priv_1)
 125                 iounmap((void *) info->map.map_priv_1);
 126
 127         if (info->res) {
 128                 release_resource(info->res);
 129                 kfree(info->res);
 130         }
 131
 132         if (plat->exit)
 133                 plat->exit();
 134
 135         return 0;
 136 }
 137
 138
 139 static int ixp2000_flash_probe(struct platform_device *dev)
 140 {
 141         static const char *probes[] = { "RedBoot", "cmdlinepart", NULL };
 142         struct ixp2000_flash_data *ixp_data = dev->dev.platform_data;
 143         struct flash_platform_data *plat;
 144         struct ixp2000_flash_info *info;
 145         unsigned long window_size;
 146         int err = -1;
 147
 148         if (!ixp_data)
 149                 return -ENODEV;
 150
 151         plat = ixp_data->platform_data;
 152         if (!plat)
 153                 return -ENODEV;
 154
 155         window_size = resource_size(dev->resource);
 156         dev_info(&dev->dev, "Probe of IXP2000 flash(%d banks x %dMiB)\n",
 157                  ixp_data->nr_banks, ((u32)window_size >> 20));
 158
 159         if (plat->width != 1) {
 160                 dev_err(&dev->dev, "IXP2000 MTD map only supports 8-bit mode, asking for %d\n",
 161                         plat->width * 8);
 162                 return -EIO;
 163         }
 164
 165         info = kzalloc(sizeof(struct ixp2000_flash_info), GFP_KERNEL);
 166         if(!info) {
 167                 err = -ENOMEM;
 168                 goto Error;
 169         }
 170
 171         platform_set_drvdata(dev, info);
 172
 173         /*
 174          * Tell the MTD layer we're not 1:1 mapped so that it does
 175          * not attempt to do a direct access on us.
 176          */
 177         info->map.phys = NO_XIP;
 178
 179         info->map.size = ixp_data->nr_banks * window_size;
 180         info->map.bankwidth = 1;
 181
 182         /*
 183          * map_priv_2 is used to store a ptr to the bank_setup routine
 184          */
 185         info->map.map_priv_2 = (unsigned long) ixp_data->bank_setup;
 186
 187         info->map.name = dev_name(&dev->dev);
 188         info->map.read = ixp2000_flash_read8;
 189         info->map.write = ixp2000_flash_write8;
 190         info->map.copy_from = ixp2000_flash_copy_from;
 191         info->map.copy_to = ixp2000_flash_copy_to;
 192
 193         info->res = request_mem_region(dev->resource->start,
 194                                        resource_size(dev->resource),
 195                                        dev_name(&dev->dev));
 196         if (!info->res) {
 197                 dev_err(&dev->dev, "Could not reserve memory region\n");
 198                 err = -ENOMEM;
 199                 goto Error;
 200         }
 201
 202         info->map.map_priv_1 =
 203                 (unsigned long)ioremap(dev->resource->start,
 204                                        resource_size(dev->resource));
 205         if (!info->map.map_priv_1) {
 206                 dev_err(&dev->dev, "Failed to ioremap flash region\n");
 207                 err = -EIO;
 208                 goto Error;
 209         }
 210
 211 #if defined(__ARMEB__)
 212         /*
 213          * Enable erratum 44 workaround for NPUs with broken slowport
 214          */
 215
 216         erratum44_workaround = ixp2000_has_broken_slowport();
 217         dev_info(&dev->dev, "Erratum 44 workaround %s\n",
 218                erratum44_workaround ? "enabled" : "disabled");
 219 #endif
 220
 221         info->mtd = do_map_probe(plat->map_name, &info->map);
 222         if (!info->mtd) {
 223                 dev_err(&dev->dev, "map_probe failed\n");
 224                 err = -ENXIO;
 225                 goto Error;
 226         }
 227         info->mtd->owner = THIS_MODULE;
 228
 229         err = mtd_device_parse_register(info->mtd, probes, 0, NULL, 0);
 230         if (err)
 231                 goto Error;
 232
 233         return 0;
 234
 235 Error:
 236         ixp2000_flash_remove(dev);
 237         return err;
 238 }
 239
 240 static struct platform_driver ixp2000_flash_driver = {
 241         .probe          = ixp2000_flash_probe,
 242         .remove         = ixp2000_flash_remove,
 243         .driver         = {
 244                 .name   = "IXP2000-Flash",
 245                 .owner  = THIS_MODULE,
 246         },
 247 };
 248
 249 module_platform_driver(ixp2000_flash_driver);
 250
 251 MODULE_LICENSE("GPL");
 252 MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>");
 253 MODULE_ALIAS("platform:IXP2000-Flash");