drivers/mtd/maps/ixp2000.c

   1 /*
   2  * $Id: ixp2000.c,v 1.1 2004/09/02 00:13:41 dsaxena 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/mtd/mtd.h>
  26 #include <linux/mtd/map.h>
  27 #include <linux/mtd/partitions.h>
  28 #include <linux/ioport.h>
  29 #include <linux/device.h>
  30
  31 #include <asm/io.h>
  32 #include <asm/hardware.h>
  33 #include <asm/mach-types.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         int             nr_banks;
  44 };
  45
  46 static inline unsigned long flash_bank_setup(struct map_info *map, unsigned long ofs)
  47 {
  48         unsigned long (*set_bank)(unsigned long) =
  49                 (unsigned long(*)(unsigned long))map->map_priv_2;
  50
  51         return (set_bank ? set_bank(ofs) : ofs);
  52 }
  53
  54 #ifdef __ARMEB__
  55 /*
  56  * Rev A0 and A1 of IXP2400 silicon have a broken addressing unit which
  57  * causes the lower address bits to be XORed with 0x11 on 8 bit accesses
  58  * and XORed with 0x10 on 16 bit accesses. See the spec update, erratta 44.
  59  */
  60 static int errata44_workaround = 0;
  61
  62 static inline unsigned long address_fix8_write(unsigned long addr)
  63 {
  64         if (errata44_workaround) {
  65                 return (addr ^ 3);
  66         }
  67         return addr;
  68 }
  69 #else
  70
  71 #define address_fix8_write(x)   (x)
  72 #endif
  73
  74 static map_word ixp2000_flash_read8(struct map_info *map, unsigned long ofs)
  75 {
  76         map_word val;
  77
  78         val.x[0] =  *((u8 *)(map->map_priv_1 + flash_bank_setup(map, ofs)));
  79         return val;
  80 }
  81
  82 /*
  83  * We can't use the standard memcpy due to the broken SlowPort
  84  * address translation on rev A0 and A1 silicon and the fact that
  85  * we have banked flash.
  86  */
  87 static void ixp2000_flash_copy_from(struct map_info *map, void *to,
  88                               unsigned long from, ssize_t len)
  89 {
  90         from = flash_bank_setup(map, from);
  91         while(len--)
  92                 *(__u8 *) to++ = *(__u8 *)(map->map_priv_1 + from++);
  93 }
  94
  95 static void ixp2000_flash_write8(struct map_info *map, map_word d, unsigned long ofs)
  96 {
  97         *(__u8 *) (address_fix8_write(map->map_priv_1 +
  98                                       flash_bank_setup(map, ofs))) = d.x[0];
  99 }
 100
 101 static void ixp2000_flash_copy_to(struct map_info *map, unsigned long to,
 102                             const void *from, ssize_t len)
 103 {
 104         to = flash_bank_setup(map, to);
 105         while(len--) {
 106                 unsigned long tmp = address_fix8_write(map->map_priv_1 + to++);
 107                 *(__u8 *)(tmp) = *(__u8 *)(from++);
 108         }
 109 }
 110
 111
 112 static int ixp2000_flash_remove(struct device *_dev)
 113 {
 114         struct platform_device *dev = to_platform_device(_dev);
 115         struct flash_platform_data *plat = dev->dev.platform_data;
 116         struct ixp2000_flash_info *info = dev_get_drvdata(&dev->dev);
 117
 118         dev_set_drvdata(&dev->dev, NULL);
 119
 120         if(!info)
 121                 return 0;
 122
 123         if (info->mtd) {
 124                 del_mtd_partitions(info->mtd);
 125                 map_destroy(info->mtd);
 126         }
 127         if (info->map.map_priv_1)
 128                 iounmap((void *) info->map.map_priv_1);
 129
 130         if (info->partitions)
 131                 kfree(info->partitions);
 132
 133         if (info->res) {
 134                 release_resource(info->res);
 135                 kfree(info->res);
 136         }
 137
 138         if (plat->exit)
 139                 plat->exit();
 140
 141         return 0;
 142 }
 143
 144
 145 static int ixp2000_flash_probe(struct device *_dev)
 146 {
 147         static const char *probes[] = { "RedBoot", "cmdlinepart", NULL };
 148         struct platform_device *dev = to_platform_device(_dev);
 149         struct ixp2000_flash_data *ixp_data = dev->dev.platform_data;
 150         struct flash_platform_data *plat;
 151         struct ixp2000_flash_info *info;
 152         unsigned long window_size;
 153         int err = -1;
 154
 155         if (!ixp_data)
 156                 return -ENODEV;
 157
 158         plat = ixp_data->platform_data;
 159         if (!plat)
 160                 return -ENODEV;
 161
 162         window_size = dev->resource->end - dev->resource->start + 1;
 163         dev_info(_dev, "Probe of IXP2000 flash(%d banks x %dM)\n",
 164                         ixp_data->nr_banks, ((u32)window_size >> 20));
 165
 166         if (plat->width != 1) {
 167                 dev_err(_dev, "IXP2000 MTD map only supports 8-bit mode, asking for %d\n",
 168                                 plat->width * 8);
 169                 return -EIO;
 170         }
 171
 172         info = kmalloc(sizeof(struct ixp2000_flash_info), GFP_KERNEL);
 173         if(!info) {
 174                 err = -ENOMEM;
 175                 goto Error;
 176         }
 177         memzero(info, sizeof(struct ixp2000_flash_info));
 178
 179         dev_set_drvdata(&dev->dev, info);
 180
 181         /*
 182          * Tell the MTD layer we're not 1:1 mapped so that it does
 183          * not attempt to do a direct access on us.
 184          */
 185         info->map.phys = NO_XIP;
 186
 187         info->nr_banks = ixp_data->nr_banks;
 188         info->map.size = ixp_data->nr_banks * window_size;
 189         info->map.bankwidth = 1;
 190
 191         /*
 192          * map_priv_2 is used to store a ptr to to the bank_setup routine
 193          */
 194         info->map.map_priv_2 = (u32) ixp_data->bank_setup;
 195
 196         info->map.name = dev->dev.bus_id;
 197         info->map.read = ixp2000_flash_read8;
 198         info->map.write = ixp2000_flash_write8;
 199         info->map.copy_from = ixp2000_flash_copy_from;
 200         info->map.copy_to = ixp2000_flash_copy_to;
 201
 202         info->res = request_mem_region(dev->resource->start,
 203                         dev->resource->end - dev->resource->start + 1,
 204                         dev->dev.bus_id);
 205         if (!info->res) {
 206                 dev_err(_dev, "Could not reserve memory region\n");
 207                 err = -ENOMEM;
 208                 goto Error;
 209         }
 210
 211         info->map.map_priv_1 =
 212             (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         /*
 221          * Setup read mode for FLASH
 222          */
 223         *IXP2000_SLOWPORT_FRM = 1;
 224
 225 #if defined(__ARMEB__)
 226         /*
 227          * Enable errata 44 workaround for NPUs with broken slowport
 228          */
 229
 230         errata44_workaround = ixp2000_has_broken_slowport();
 231         dev_info(_dev, "Errata 44 workaround %s\n",
 232                errata44_workaround ? "enabled" : "disabled");
 233 #endif
 234
 235         info->mtd = do_map_probe(plat->map_name, &info->map);
 236         if (!info->mtd) {
 237                 dev_err(_dev, "map_probe failed\n");
 238                 err = -ENXIO;
 239                 goto Error;
 240         }
 241         info->mtd->owner = THIS_MODULE;
 242
 243         err = parse_mtd_partitions(info->mtd, probes, &info->partitions, 0);
 244         if (err > 0) {
 245                 err = add_mtd_partitions(info->mtd, info->partitions, err);
 246                 if(err)
 247                         dev_err(_dev, "Could not parse partitions\n");
 248         }
 249
 250         if (err)
 251                 goto Error;
 252
 253         return 0;
 254
 255 Error:
 256         ixp2000_flash_remove(_dev);
 257         return err;
 258 }
 259
 260 static struct device_driver ixp2000_flash_driver = {
 261         .name           = "IXP2000-Flash",
 262         .bus            = &platform_bus_type,
 263         .probe          = &ixp2000_flash_probe,
 264         .remove         = &ixp2000_flash_remove
 265 };
 266
 267 static int __init ixp2000_flash_init(void)
 268 {
 269         return driver_register(&ixp2000_flash_driver);
 270 }
 271
 272 static void __exit ixp2000_flash_exit(void)
 273 {
 274         driver_unregister(&ixp2000_flash_driver);
 275 }
 276
 277 module_init(ixp2000_flash_init);
 278 module_exit(ixp2000_flash_exit);
 279 MODULE_LICENSE("GPL");
 280 MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>");
 281