drivers/mtd/maps/ixp4xx.c

   1 /*
   2  * $Id: ixp4xx.c,v 1.4 2004/10/19 06:41:34 gerg Exp $
   3  *
   4  * drivers/mtd/maps/ixp425.c
   5  *
   6  * MTD Map file for IXP4XX based systems. Please do not make per-board
   7  * map driver as the code will be 90% identical. For now just add
   8  * if(machine_is_XXX()) checks to the code. I'll clean this stuff to
   9  * use platform_data in the the future so we can get rid of that too.
  10  *
  11  * Original Author: Intel Corporation
  12  * Maintainer: Deepak Saxena <dsaxena@mvista.com>
  13  *
  14  * Copyright (C) 2002 Intel Corporation
  15  * Copyright (C) 2003 MontaVista Software, Inc.
  16  *
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/types.h>
  21 #include <linux/init.h>
  22 #include <linux/kernel.h>
  23 #include <linux/string.h>
  24 #include <linux/mtd/mtd.h>
  25 #include <linux/mtd/map.h>
  26 #include <linux/mtd/partitions.h>
  27 #include <linux/ioport.h>
  28 #include <linux/device.h>
  29 #include <asm/io.h>
  30 #include <asm/mach-types.h>
  31 #include <asm/mach/flash.h>
  32
  33 #include <linux/reboot.h>
  34
  35 #ifndef __ARMEB__
  36 #define BYTE0(h)        ((h) & 0xFF)
  37 #define BYTE1(h)        (((h) >> 8) & 0xFF)
  38 #else
  39 #define BYTE0(h)        (((h) >> 8) & 0xFF)
  40 #define BYTE1(h)        ((h) & 0xFF)
  41 #endif
  42
  43 static map_word ixp4xx_read16(struct map_info *map, unsigned long ofs)
  44 {
  45         map_word val;
  46         val.x[0] = *(__u16 *) (map->map_priv_1 + ofs);
  47         return val;
  48 }
  49
  50 /*
  51  * The IXP4XX expansion bus only allows 16-bit wide acceses
  52  * when attached to a 16-bit wide device (such as the 28F128J3A),
  53  * so we can't just memcpy_fromio().
  54  */
  55 static void ixp4xx_copy_from(struct map_info *map, void *to,
  56                              unsigned long from, ssize_t len)
  57 {
  58         int i;
  59         u8 *dest = (u8 *) to;
  60         u16 *src = (u16 *) (map->map_priv_1 + from);
  61         u16 data;
  62
  63         for (i = 0; i < (len / 2); i++) {
  64 #ifdef __ARMEB__
  65                 data = src[i];
  66 #else
  67                 data = src[i ^ 1];
  68 #endif
  69                 dest[i * 2] = BYTE0(data);
  70                 dest[i * 2 + 1] = BYTE1(data);
  71         }
  72
  73         if (len & 1)
  74 #ifdef __ARMEB__
  75                 dest[len - 1] = BYTE0(src[i]);
  76 #else
  77                 dest[len - 1] = BYTE0(src[i ^ 1]);
  78 #endif
  79 }
  80
  81 /*
  82  * Unaligned writes are ignored, causing the 8-bit
  83  * probe to fail and proceed to the 16-bit probe (which succeeds).
  84  */
  85 static void ixp4xx_probe_write16(struct map_info *map, map_word d, unsigned long adr)
  86 {
  87         if (!(adr & 1))
  88                *(__u16 *) (map->map_priv_1 + adr) = d.x[0];
  89 }
  90
  91 /*
  92  * Fast write16 function without the probing check above
  93  */
  94 static void ixp4xx_write16(struct map_info *map, map_word d, unsigned long adr)
  95 {
  96        *(__u16 *) (map->map_priv_1 + adr) = d.x[0];
  97 }
  98
  99 struct ixp425_flash_info {
 100         struct mtd_info *mtd;
 101         struct map_info map;
 102         struct mtd_partition *partitions;
 103         struct resource *res;
 104 };
 105
 106 static const char *probes[] = { "RedBoot", "cmdlinepart", NULL };
 107
 108 static int ixp4xx_flash_remove(struct device *_dev)
 109 {
 110         struct platform_device *dev = to_platform_device(_dev);
 111         struct flash_platform_data *plat = dev->dev.platform_data;
 112         struct ixp4xx_flash_info *info = dev_get_drvdata(&dev->dev);
 113         map_word d;
 114
 115         dev_set_drvdata(&dev->dev, NULL);
 116
 117         /*
 118          * Reboot hack...
 119          */
 120         d.x[0] = 0xff;
 121         ixp4xx_write16(&info->map, d, 0x55 * 0x2);
 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         /* Disable flash write */
 139         *IXP4XX_EXP_CS0 &= ~IXP4XX_FLASH_WRITABLE;
 140
 141         return 0;
 142 }
 143
 144 static int ixp425_flash_probe(struct device *_dev)
 145 {
 146         struct platform_device *dev = to_platform_device(_dev);
 147         struct flash_platform_data *plat = dev->dev.platform_data;
 148         struct ixp425_flash_info *info;
 149         int err = -1;
 150
 151         info = kmalloc(sizeof(struct ixp425_flash_info), GFP_KERNEL);
 152         if(!info) {
 153                 err = -ENOMEM;
 154                 goto Error;
 155         }
 156         memzero(info, sizeof(struct ixp425_flash_info));
 157
 158         dev_set_drvdata(&dev->dev, info);
 159
 160         /* Enable flash write */
 161         *IXP4XX_EXP_CS0 |= IXP4XX_FLASH_WRITABLE;
 162
 163         /*
 164          * We only support 16-bit accesses for now. If and when
 165          * any board use 8-bit access, we'll fixup the driver to
 166          * handle that.
 167          */
 168         info->map.bankwidth = 2;
 169         info->map.name = dev->dev.bus_id;
 170         info->map.read = ixp4xx_read16,
 171         info->map.write = ixp4xx_probe_write16,
 172         info->map.copy_from = ixp4xx_copy_from,
 173
 174         info->res = request_mem_region(dev->resource->start,
 175                         dev->resource->end - dev->resource->start + 1,
 176                         "IXP4XXFlash");
 177         if (!info->res) {
 178                 printk(KERN_ERR "IXP4XXFlash: Could not reserve memory region\n");
 179                 err = -ENOMEM;
 180                 goto Error;
 181         }
 182
 183         info->map.map_priv_1 =
 184             (void __iomem *) ioremap(dev->resource->start,
 185                                     dev->resource->end - dev->resource->start + 1);
 186         if (!info->map.map_priv_1) {
 187                 printk(KERN_ERR "IXP4XXFlash: Failed to ioremap region\n");
 188                 err = -EIO;
 189                 goto Error;
 190         }
 191
 192         info->mtd = do_map_probe(plat->map_name, &info->map);
 193         if (!info->mtd) {
 194                 printk(KERN_ERR "IXP4XXFlash: map_probe failed\n");
 195                 err = -ENXIO;
 196                 goto Error;
 197         }
 198         info->mtd->owner = THIS_MODULE;
 199
 200         /* Use the fast version */
 201         info->map.write = ixp4xx_write16,
 202
 203         err = parse_mtd_partitions(info->mtd, probes, &info->partitions, 0);
 204         if (err > 0) {
 205                 err = add_mtd_partitions(info->mtd, info->partitions, err);
 206                 if(err)
 207                         printk(KERN_ERR "Could not parse partitions\n");
 208         }
 209
 210         if (err)
 211                 goto Error;
 212
 213         return 0;
 214
 215 Error:
 216         ixp425_flash_remove(_dev);
 217         return err;
 218 }
 219
 220 static struct device_driver ixp425_flash_driver = {
 221         .name           = "IXP4XX-Flash",
 222         .bus            = &platform_bus_type,
 223         .probe          = ixp425_flash_probe,
 224         .remove         = ixp425_flash_remove,
 225 };
 226
 227 static int __init ixp425_flash_init(void)
 228 {
 229         return driver_register(&ixp425_flash_driver);
 230 }
 231
 232 static void __exit ixp425_flash_exit(void)
 233 {
 234         driver_unregister(&ixp425_flash_driver);
 235 }
 236
 237
 238 module_init(ixp425_flash_init);
 239 module_exit(ixp425_flash_exit);
 240
 241 MODULE_LICENSE("GPL");
 242 MODULE_DESCRIPTION("MTD map driver for ixp425 evaluation board");
 243 MODULE_AUTHOR("Deepak Saxena");
 244