drivers/mtd/maps/ixp4xx.c

   1 /*
   2  * $Id: ixp4xx.c,v 1.7 2004/11/04 13:24:15 gleixner Exp $
   3  *
   4  * drivers/mtd/maps/ixp4xx.c
   5  *
   6  * MTD Map file for IXP4XX based systems. Please do not make per-board
   7  * changes in here. If your board needs special setup, do it in your
   8  * platform level code in arch/arm/mach-ixp4xx/board-setup.c
   9  *
  10  * Original Author: Intel Corporation
  11  * Maintainer: Deepak Saxena <dsaxena@mvista.com>
  12  *
  13  * Copyright (C) 2002 Intel Corporation
  14  * Copyright (C) 2003-2004 MontaVista Software, Inc.
  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/mtd/mtd.h>
  24 #include <linux/mtd/map.h>
  25 #include <linux/mtd/partitions.h>
  26 #include <linux/ioport.h>
  27 #include <linux/device.h>
  28 #include <asm/io.h>
  29 #include <asm/mach-types.h>
  30 #include <asm/mach/flash.h>
  31
  32 #include <linux/reboot.h>
  33
  34 #ifndef __ARMEB__
  35 #define BYTE0(h)        ((h) & 0xFF)
  36 #define BYTE1(h)        (((h) >> 8) & 0xFF)
  37 #else
  38 #define BYTE0(h)        (((h) >> 8) & 0xFF)
  39 #define BYTE1(h)        ((h) & 0xFF)
  40 #endif
  41
  42 static map_word ixp4xx_read16(struct map_info *map, unsigned long ofs)
  43 {
  44         map_word val;
  45         val.x[0] = *(__u16 *) (map->map_priv_1 + ofs);
  46         return val;
  47 }
  48
  49 /*
  50  * The IXP4xx expansion bus only allows 16-bit wide acceses
  51  * when attached to a 16-bit wide device (such as the 28F128J3A),
  52  * so we can't just memcpy_fromio().
  53  */
  54 static void ixp4xx_copy_from(struct map_info *map, void *to,
  55                              unsigned long from, ssize_t len)
  56 {
  57         int i;
  58         u8 *dest = (u8 *) to;
  59         u16 *src = (u16 *) (map->map_priv_1 + from);
  60         u16 data;
  61
  62         for (i = 0; i < (len / 2); i++) {
  63                 data = src[i];
  64                 dest[i * 2] = BYTE0(data);
  65                 dest[i * 2 + 1] = BYTE1(data);
  66         }
  67
  68         if (len & 1)
  69                 dest[len - 1] = BYTE0(src[i]);
  70 }
  71
  72 /*
  73  * Unaligned writes are ignored, causing the 8-bit
  74  * probe to fail and proceed to the 16-bit probe (which succeeds).
  75  */
  76 static void ixp4xx_probe_write16(struct map_info *map, map_word d, unsigned long adr)
  77 {
  78         if (!(adr & 1))
  79                *(__u16 *) (map->map_priv_1 + adr) = d.x[0];
  80 }
  81
  82 /*
  83  * Fast write16 function without the probing check above
  84  */
  85 static void ixp4xx_write16(struct map_info *map, map_word d, unsigned long adr)
  86 {
  87        *(__u16 *) (map->map_priv_1 + adr) = d.x[0];
  88 }
  89
  90 struct ixp4xx_flash_info {
  91         struct mtd_info *mtd;
  92         struct map_info map;
  93         struct mtd_partition *partitions;
  94         struct resource *res;
  95 };
  96
  97 static const char *probes[] = { "RedBoot", "cmdlinepart", NULL };
  98
  99 static int ixp4xx_flash_remove(struct device *_dev)
 100 {
 101         struct platform_device *dev = to_platform_device(_dev);
 102         struct flash_platform_data *plat = dev->dev.platform_data;
 103         struct ixp4xx_flash_info *info = dev_get_drvdata(&dev->dev);
 104         map_word d;
 105
 106         dev_set_drvdata(&dev->dev, NULL);
 107
 108         if(!info)
 109                 return 0;
 110
 111         /*
 112          * This is required for a soft reboot to work.
 113          */
 114         d.x[0] = 0xff;
 115         ixp4xx_write16(&info->map, d, 0x55 * 0x2);
 116
 117         if (info->mtd) {
 118                 del_mtd_partitions(info->mtd);
 119                 map_destroy(info->mtd);
 120         }
 121         if (info->map.map_priv_1)
 122                 iounmap((void *) info->map.map_priv_1);
 123
 124         if (info->partitions)
 125                 kfree(info->partitions);
 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         /* Disable flash write */
 136         *IXP4XX_EXP_CS0 &= ~IXP4XX_FLASH_WRITABLE;
 137
 138         return 0;
 139 }
 140
 141 static int ixp4xx_flash_probe(struct device *_dev)
 142 {
 143         struct platform_device *dev = to_platform_device(_dev);
 144         struct flash_platform_data *plat = dev->dev.platform_data;
 145         struct ixp4xx_flash_info *info;
 146         int err = -1;
 147
 148         if (!plat)
 149                 return -ENODEV;
 150
 151         if (plat->init) {
 152                 err = plat->init();
 153                 if (err)
 154                         return err;
 155         }
 156
 157         info = kmalloc(sizeof(struct ixp4xx_flash_info), GFP_KERNEL);
 158         if(!info) {
 159                 err = -ENOMEM;
 160                 goto Error;
 161         }
 162         memzero(info, sizeof(struct ixp4xx_flash_info));
 163
 164         dev_set_drvdata(&dev->dev, info);
 165
 166         /*
 167          * Enable flash write
 168          * TODO: Move this out to board specific code
 169          */
 170         *IXP4XX_EXP_CS0 |= IXP4XX_FLASH_WRITABLE;
 171
 172         /*
 173          * Tell the MTD layer we're not 1:1 mapped so that it does
 174          * not attempt to do a direct access on us.
 175          */
 176         info->map.phys = NO_XIP;
 177         info->map.size = dev->resource->end - dev->resource->start + 1;
 178
 179         /*
 180          * We only support 16-bit accesses for now. If and when
 181          * any board use 8-bit access, we'll fixup the driver to
 182          * handle that.
 183          */
 184         info->map.bankwidth = 2;
 185         info->map.name = dev->dev.bus_id;
 186         info->map.read = ixp4xx_read16,
 187         info->map.write = ixp4xx_probe_write16,
 188         info->map.copy_from = ixp4xx_copy_from,
 189
 190         info->res = request_mem_region(dev->resource->start,
 191                         dev->resource->end - dev->resource->start + 1,
 192                         "IXP4XXFlash");
 193         if (!info->res) {
 194                 printk(KERN_ERR "IXP4XXFlash: Could not reserve memory region\n");
 195                 err = -ENOMEM;
 196                 goto Error;
 197         }
 198
 199         info->map.map_priv_1 = ioremap(dev->resource->start,
 200                             dev->resource->end - dev->resource->start + 1);
 201         if (!info->map.map_priv_1) {
 202                 printk(KERN_ERR "IXP4XXFlash: Failed to ioremap region\n");
 203                 err = -EIO;
 204                 goto Error;
 205         }
 206
 207         info->mtd = do_map_probe(plat->map_name, &info->map);
 208         if (!info->mtd) {
 209                 printk(KERN_ERR "IXP4XXFlash: map_probe failed\n");
 210                 err = -ENXIO;
 211                 goto Error;
 212         }
 213         info->mtd->owner = THIS_MODULE;
 214
 215         /* Use the fast version */
 216         info->map.write = ixp4xx_write16,
 217
 218         err = parse_mtd_partitions(info->mtd, probes, &info->partitions, 0);
 219         if (err > 0) {
 220                 err = add_mtd_partitions(info->mtd, info->partitions, err);
 221                 if(err)
 222                         printk(KERN_ERR "Could not parse partitions\n");
 223         }
 224
 225         if (err)
 226                 goto Error;
 227
 228         return 0;
 229
 230 Error:
 231         ixp4xx_flash_remove(_dev);
 232         return err;
 233 }
 234
 235 static struct device_driver ixp4xx_flash_driver = {
 236         .name           = "IXP4XX-Flash",
 237         .bus            = &platform_bus_type,
 238         .probe          = ixp4xx_flash_probe,
 239         .remove         = ixp4xx_flash_remove,
 240 };
 241
 242 static int __init ixp4xx_flash_init(void)
 243 {
 244         return driver_register(&ixp4xx_flash_driver);
 245 }
 246
 247 static void __exit ixp4xx_flash_exit(void)
 248 {
 249         driver_unregister(&ixp4xx_flash_driver);
 250 }
 251
 252
 253 module_init(ixp4xx_flash_init);
 254 module_exit(ixp4xx_flash_exit);
 255
 256 MODULE_LICENSE("GPL");
 257 MODULE_DESCRIPTION("MTD map driver for Intel IXP4xx systems")
 258 MODULE_AUTHOR("Deepak Saxena");
 259