drivers/mtd/devices/ms02-nv.c

   1 /*
   2  *      Copyright (c) 2001 Maciej W. Rozycki
   3  *
   4  *      This program is free software; you can redistribute it and/or
   5  *      modify it under the terms of the GNU General Public License
   6  *      as published by the Free Software Foundation; either version
   7  *      2 of the License, or (at your option) any later version.
   8  *
   9  *      $Id: ms02-nv.c,v 1.11 2005/11/14 13:41:47 macro Exp $
  10  */
  11
  12 #include <linux/init.h>
  13 #include <linux/ioport.h>
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/mtd/mtd.h>
  17 #include <linux/slab.h>
  18 #include <linux/types.h>
  19
  20 #include <asm/addrspace.h>
  21 #include <asm/bootinfo.h>
  22 #include <asm/dec/ioasic_addrs.h>
  23 #include <asm/dec/kn02.h>
  24 #include <asm/dec/kn03.h>
  25 #include <asm/io.h>
  26 #include <asm/paccess.h>
  27
  28 #include "ms02-nv.h"
  29
  30
  31 static char version[] __initdata =
  32         "ms02-nv.c: v.1.0.0  13 Aug 2001  Maciej W. Rozycki.\n";
  33
  34 MODULE_AUTHOR("Maciej W. Rozycki <macro@linux-mips.org>");
  35 MODULE_DESCRIPTION("DEC MS02-NV NVRAM module driver");
  36 MODULE_LICENSE("GPL");
  37
  38
  39 /*
  40  * Addresses we probe for an MS02-NV at.  Modules may be located
  41  * at any 8MiB boundary within a 0MiB up to 112MiB range or at any 32MiB
  42  * boundary within a 0MiB up to 448MiB range.  We don't support a module
  43  * at 0MiB, though.
  44  */
  45 static ulong ms02nv_addrs[] __initdata = {
  46         0x07000000, 0x06800000, 0x06000000, 0x05800000, 0x05000000,
  47         0x04800000, 0x04000000, 0x03800000, 0x03000000, 0x02800000,
  48         0x02000000, 0x01800000, 0x01000000, 0x00800000
  49 };
  50
  51 static const char ms02nv_name[] = "DEC MS02-NV NVRAM";
  52 static const char ms02nv_res_diag_ram[] = "Diagnostic RAM";
  53 static const char ms02nv_res_user_ram[] = "General-purpose RAM";
  54 static const char ms02nv_res_csr[] = "Control and status register";
  55
  56 static struct mtd_info *root_ms02nv_mtd;
  57
  58
  59 static int ms02nv_read(struct mtd_info *mtd, loff_t from,
  60                         size_t len, size_t *retlen, u_char *buf)
  61 {
  62         struct ms02nv_private *mp = mtd->priv;
  63
  64         if (from + len > mtd->size)
  65                 return -EINVAL;
  66
  67         memcpy(buf, mp->uaddr + from, len);
  68         *retlen = len;
  69
  70         return 0;
  71 }
  72
  73 static int ms02nv_write(struct mtd_info *mtd, loff_t to,
  74                         size_t len, size_t *retlen, const u_char *buf)
  75 {
  76         struct ms02nv_private *mp = mtd->priv;
  77
  78         if (to + len > mtd->size)
  79                 return -EINVAL;
  80
  81         memcpy(mp->uaddr + to, buf, len);
  82         *retlen = len;
  83
  84         return 0;
  85 }
  86
  87
  88 static inline uint ms02nv_probe_one(ulong addr)
  89 {
  90         ms02nv_uint *ms02nv_diagp;
  91         ms02nv_uint *ms02nv_magicp;
  92         uint ms02nv_diag;
  93         uint ms02nv_magic;
  94         size_t size;
  95
  96         int err;
  97
  98         /*
  99          * The firmware writes MS02NV_ID at MS02NV_MAGIC and also
 100          * a diagnostic status at MS02NV_DIAG.
 101          */
 102         ms02nv_diagp = (ms02nv_uint *)(CKSEG1ADDR(addr + MS02NV_DIAG));
 103         ms02nv_magicp = (ms02nv_uint *)(CKSEG1ADDR(addr + MS02NV_MAGIC));
 104         err = get_dbe(ms02nv_magic, ms02nv_magicp);
 105         if (err)
 106                 return 0;
 107         if (ms02nv_magic != MS02NV_ID)
 108                 return 0;
 109
 110         ms02nv_diag = *ms02nv_diagp;
 111         size = (ms02nv_diag & MS02NV_DIAG_SIZE_MASK) << MS02NV_DIAG_SIZE_SHIFT;
 112         if (size > MS02NV_CSR)
 113                 size = MS02NV_CSR;
 114
 115         return size;
 116 }
 117
 118 static int __init ms02nv_init_one(ulong addr)
 119 {
 120         struct mtd_info *mtd;
 121         struct ms02nv_private *mp;
 122         struct resource *mod_res;
 123         struct resource *diag_res;
 124         struct resource *user_res;
 125         struct resource *csr_res;
 126         ulong fixaddr;
 127         size_t size, fixsize;
 128
 129         static int version_printed;
 130
 131         int ret = -ENODEV;
 132
 133         /* The module decodes 8MiB of address space. */
 134         mod_res = kzalloc(sizeof(*mod_res), GFP_KERNEL);
 135         if (!mod_res)
 136                 return -ENOMEM;
 137
 138         mod_res->name = ms02nv_name;
 139         mod_res->start = addr;
 140         mod_res->end = addr + MS02NV_SLOT_SIZE - 1;
 141         mod_res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 142         if (request_resource(&iomem_resource, mod_res) < 0)
 143                 goto err_out_mod_res;
 144
 145         size = ms02nv_probe_one(addr);
 146         if (!size)
 147                 goto err_out_mod_res_rel;
 148
 149         if (!version_printed) {
 150                 printk(KERN_INFO "%s", version);
 151                 version_printed = 1;
 152         }
 153
 154         ret = -ENOMEM;
 155         mtd = kzalloc(sizeof(*mtd), GFP_KERNEL);
 156         if (!mtd)
 157                 goto err_out_mod_res_rel;
 158         mp = kzalloc(sizeof(*mp), GFP_KERNEL);
 159         if (!mp)
 160                 goto err_out_mtd;
 161
 162         mtd->priv = mp;
 163         mp->resource.module = mod_res;
 164
 165         /* Firmware's diagnostic NVRAM area. */
 166         diag_res = kzalloc(sizeof(*diag_res), GFP_KERNEL);
 167         if (!diag_res)
 168                 goto err_out_mp;
 169
 170         diag_res->name = ms02nv_res_diag_ram;
 171         diag_res->start = addr;
 172         diag_res->end = addr + MS02NV_RAM - 1;
 173         diag_res->flags = IORESOURCE_BUSY;
 174         request_resource(mod_res, diag_res);
 175
 176         mp->resource.diag_ram = diag_res;
 177
 178         /* User-available general-purpose NVRAM area. */
 179         user_res = kzalloc(sizeof(*user_res), GFP_KERNEL);
 180         if (!user_res)
 181                 goto err_out_diag_res;
 182
 183         user_res->name = ms02nv_res_user_ram;
 184         user_res->start = addr + MS02NV_RAM;
 185         user_res->end = addr + size - 1;
 186         user_res->flags = IORESOURCE_BUSY;
 187         request_resource(mod_res, user_res);
 188
 189         mp->resource.user_ram = user_res;
 190
 191         /* Control and status register. */
 192         csr_res = kzalloc(sizeof(*csr_res), GFP_KERNEL);
 193         if (!csr_res)
 194                 goto err_out_user_res;
 195
 196         csr_res->name = ms02nv_res_csr;
 197         csr_res->start = addr + MS02NV_CSR;
 198         csr_res->end = addr + MS02NV_CSR + 3;
 199         csr_res->flags = IORESOURCE_BUSY;
 200         request_resource(mod_res, csr_res);
 201
 202         mp->resource.csr = csr_res;
 203
 204         mp->addr = phys_to_virt(addr);
 205         mp->size = size;
 206
 207         /*
 208          * Hide the firmware's diagnostic area.  It may get destroyed
 209          * upon a reboot.  Take paging into account for mapping support.
 210          */
 211         fixaddr = (addr + MS02NV_RAM + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1);
 212         fixsize = (size - (fixaddr - addr)) & ~(PAGE_SIZE - 1);
 213         mp->uaddr = phys_to_virt(fixaddr);
 214
 215         mtd->type = MTD_RAM;
 216         mtd->flags = MTD_CAP_RAM;
 217         mtd->size = fixsize;
 218         mtd->name = (char *)ms02nv_name;
 219         mtd->owner = THIS_MODULE;
 220         mtd->read = ms02nv_read;
 221         mtd->write = ms02nv_write;
 222         mtd->writesize = 1;
 223
 224         ret = -EIO;
 225         if (add_mtd_device(mtd)) {
 226                 printk(KERN_ERR
 227                         "ms02-nv: Unable to register MTD device, aborting!\n");
 228                 goto err_out_csr_res;
 229         }
 230
 231         printk(KERN_INFO "mtd%d: %s at 0x%08lx, size %zuMiB.\n",
 232                 mtd->index, ms02nv_name, addr, size >> 20);
 233
 234         mp->next = root_ms02nv_mtd;
 235         root_ms02nv_mtd = mtd;
 236
 237         return 0;
 238
 239
 240 err_out_csr_res:
 241         release_resource(csr_res);
 242         kfree(csr_res);
 243 err_out_user_res:
 244         release_resource(user_res);
 245         kfree(user_res);
 246 err_out_diag_res:
 247         release_resource(diag_res);
 248         kfree(diag_res);
 249 err_out_mp:
 250         kfree(mp);
 251 err_out_mtd:
 252         kfree(mtd);
 253 err_out_mod_res_rel:
 254         release_resource(mod_res);
 255 err_out_mod_res:
 256         kfree(mod_res);
 257         return ret;
 258 }
 259
 260 static void __exit ms02nv_remove_one(void)
 261 {
 262         struct mtd_info *mtd = root_ms02nv_mtd;
 263         struct ms02nv_private *mp = mtd->priv;
 264
 265         root_ms02nv_mtd = mp->next;
 266
 267         del_mtd_device(mtd);
 268
 269         release_resource(mp->resource.csr);
 270         kfree(mp->resource.csr);
 271         release_resource(mp->resource.user_ram);
 272         kfree(mp->resource.user_ram);
 273         release_resource(mp->resource.diag_ram);
 274         kfree(mp->resource.diag_ram);
 275         release_resource(mp->resource.module);
 276         kfree(mp->resource.module);
 277         kfree(mp);
 278         kfree(mtd);
 279 }
 280
 281
 282 static int __init ms02nv_init(void)
 283 {
 284         volatile u32 *csr;
 285         uint stride = 0;
 286         int count = 0;
 287         int i;
 288
 289         switch (mips_machtype) {
 290         case MACH_DS5000_200:
 291                 csr = (volatile u32 *)CKSEG1ADDR(KN02_SLOT_BASE + KN02_CSR);
 292                 if (*csr & KN02_CSR_BNK32M)
 293                         stride = 2;
 294                 break;
 295         case MACH_DS5000_2X0:
 296         case MACH_DS5900:
 297                 csr = (volatile u32 *)CKSEG1ADDR(KN03_SLOT_BASE + IOASIC_MCR);
 298                 if (*csr & KN03_MCR_BNK32M)
 299                         stride = 2;
 300                 break;
 301         default:
 302                 return -ENODEV;
 303                 break;
 304         }
 305
 306         for (i = 0; i < ARRAY_SIZE(ms02nv_addrs); i++)
 307                 if (!ms02nv_init_one(ms02nv_addrs[i] << stride))
 308                         count++;
 309
 310         return (count > 0) ? 0 : -ENODEV;
 311 }
 312
 313 static void __exit ms02nv_cleanup(void)
 314 {
 315         while (root_ms02nv_mtd)
 316                 ms02nv_remove_one();
 317 }
 318
 319
 320 module_init(ms02nv_init);
 321 module_exit(ms02nv_cleanup);