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