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         if (from + len > mtd->size)
  63                 return -EINVAL;
  64
  65         memcpy(buf, mp->uaddr + from, len);
  66         *retlen = len;
  67
  68         return 0;
  69 }
  70
  71 static int ms02nv_write(struct mtd_info *mtd, loff_t to,
  72                         size_t len, size_t *retlen, const u_char *buf)
  73 {
  74         struct ms02nv_private *mp = mtd->priv;
  75
  76         if (to + len > mtd->size)
  77                 return -EINVAL;
  78
  79         memcpy(mp->uaddr + to, buf, len);
  80         *retlen = len;
  81
  82         return 0;
  83 }
  84
  85
  86 static inline uint ms02nv_probe_one(ulong addr)
  87 {
  88         ms02nv_uint *ms02nv_diagp;
  89         ms02nv_uint *ms02nv_magicp;
  90         uint ms02nv_diag;
  91         uint ms02nv_magic;
  92         size_t size;
  93
  94         int err;
  95
  96         /*
  97          * The firmware writes MS02NV_ID at MS02NV_MAGIC and also
  98          * a diagnostic status at MS02NV_DIAG.
  99          */
 100         ms02nv_diagp = (ms02nv_uint *)(CKSEG1ADDR(addr + MS02NV_DIAG));
 101         ms02nv_magicp = (ms02nv_uint *)(CKSEG1ADDR(addr + MS02NV_MAGIC));
 102         err = get_dbe(ms02nv_magic, ms02nv_magicp);
 103         if (err)
 104                 return 0;
 105         if (ms02nv_magic != MS02NV_ID)
 106                 return 0;
 107
 108         ms02nv_diag = *ms02nv_diagp;
 109         size = (ms02nv_diag & MS02NV_DIAG_SIZE_MASK) << MS02NV_DIAG_SIZE_SHIFT;
 110         if (size > MS02NV_CSR)
 111                 size = MS02NV_CSR;
 112
 113         return size;
 114 }
 115
 116 static int __init ms02nv_init_one(ulong addr)
 117 {
 118         struct mtd_info *mtd;
 119         struct ms02nv_private *mp;
 120         struct resource *mod_res;
 121         struct resource *diag_res;
 122         struct resource *user_res;
 123         struct resource *csr_res;
 124         ulong fixaddr;
 125         size_t size, fixsize;
 126
 127         static int version_printed;
 128
 129         int ret = -ENODEV;
 130
 131         /* The module decodes 8MiB of address space. */
 132         mod_res = kzalloc(sizeof(*mod_res), GFP_KERNEL);
 133         if (!mod_res)
 134                 return -ENOMEM;
 135
 136         mod_res->name = ms02nv_name;
 137         mod_res->start = addr;
 138         mod_res->end = addr + MS02NV_SLOT_SIZE - 1;
 139         mod_res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 140         if (request_resource(&iomem_resource, mod_res) < 0)
 141                 goto err_out_mod_res;
 142
 143         size = ms02nv_probe_one(addr);
 144         if (!size)
 145                 goto err_out_mod_res_rel;
 146
 147         if (!version_printed) {
 148                 printk(KERN_INFO "%s", version);
 149                 version_printed = 1;
 150         }
 151
 152         ret = -ENOMEM;
 153         mtd = kzalloc(sizeof(*mtd), GFP_KERNEL);
 154         if (!mtd)
 155                 goto err_out_mod_res_rel;
 156         mp = kzalloc(sizeof(*mp), GFP_KERNEL);
 157         if (!mp)
 158                 goto err_out_mtd;
 159
 160         mtd->priv = mp;
 161         mp->resource.module = mod_res;
 162
 163         /* Firmware's diagnostic NVRAM area. */
 164         diag_res = kzalloc(sizeof(*diag_res), GFP_KERNEL);
 165         if (!diag_res)
 166                 goto err_out_mp;
 167
 168         diag_res->name = ms02nv_res_diag_ram;
 169         diag_res->start = addr;
 170         diag_res->end = addr + MS02NV_RAM - 1;
 171         diag_res->flags = IORESOURCE_BUSY;
 172         request_resource(mod_res, diag_res);
 173
 174         mp->resource.diag_ram = diag_res;
 175
 176         /* User-available general-purpose NVRAM area. */
 177         user_res = kzalloc(sizeof(*user_res), GFP_KERNEL);
 178         if (!user_res)
 179                 goto err_out_diag_res;
 180
 181         user_res->name = ms02nv_res_user_ram;
 182         user_res->start = addr + MS02NV_RAM;
 183         user_res->end = addr + size - 1;
 184         user_res->flags = IORESOURCE_BUSY;
 185         request_resource(mod_res, user_res);
 186
 187         mp->resource.user_ram = user_res;
 188
 189         /* Control and status register. */
 190         csr_res = kzalloc(sizeof(*csr_res), GFP_KERNEL);
 191         if (!csr_res)
 192                 goto err_out_user_res;
 193
 194         csr_res->name = ms02nv_res_csr;
 195         csr_res->start = addr + MS02NV_CSR;
 196         csr_res->end = addr + MS02NV_CSR + 3;
 197         csr_res->flags = IORESOURCE_BUSY;
 198         request_resource(mod_res, csr_res);
 199
 200         mp->resource.csr = csr_res;
 201
 202         mp->addr = phys_to_virt(addr);
 203         mp->size = size;
 204
 205         /*
 206          * Hide the firmware's diagnostic area.  It may get destroyed
 207          * upon a reboot.  Take paging into account for mapping support.
 208          */
 209         fixaddr = (addr + MS02NV_RAM + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1);
 210         fixsize = (size - (fixaddr - addr)) & ~(PAGE_SIZE - 1);
 211         mp->uaddr = phys_to_virt(fixaddr);
 212
 213         mtd->type = MTD_RAM;
 214         mtd->flags = MTD_CAP_RAM;
 215         mtd->size = fixsize;
 216         mtd->name = (char *)ms02nv_name;
 217         mtd->owner = THIS_MODULE;
 218         mtd->read = ms02nv_read;
 219         mtd->write = ms02nv_write;
 220         mtd->writesize = 1;
 221
 222         ret = -EIO;
 223         if (mtd_device_register(mtd, NULL, 0)) {
 224                 printk(KERN_ERR
 225                         "ms02-nv: Unable to register MTD device, aborting!\n");
 226                 goto err_out_csr_res;
 227         }
 228
 229         printk(KERN_INFO "mtd%d: %s at 0x%08lx, size %zuMiB.\n",
 230                 mtd->index, ms02nv_name, addr, size >> 20);
 231
 232         mp->next = root_ms02nv_mtd;
 233         root_ms02nv_mtd = mtd;
 234
 235         return 0;
 236
 237
 238 err_out_csr_res:
 239         release_resource(csr_res);
 240         kfree(csr_res);
 241 err_out_user_res:
 242         release_resource(user_res);
 243         kfree(user_res);
 244 err_out_diag_res:
 245         release_resource(diag_res);
 246         kfree(diag_res);
 247 err_out_mp:
 248         kfree(mp);
 249 err_out_mtd:
 250         kfree(mtd);
 251 err_out_mod_res_rel:
 252         release_resource(mod_res);
 253 err_out_mod_res:
 254         kfree(mod_res);
 255         return ret;
 256 }
 257
 258 static void __exit ms02nv_remove_one(void)
 259 {
 260         struct mtd_info *mtd = root_ms02nv_mtd;
 261         struct ms02nv_private *mp = mtd->priv;
 262
 263         root_ms02nv_mtd = mp->next;
 264
 265         mtd_device_unregister(mtd);
 266
 267         release_resource(mp->resource.csr);
 268         kfree(mp->resource.csr);
 269         release_resource(mp->resource.user_ram);
 270         kfree(mp->resource.user_ram);
 271         release_resource(mp->resource.diag_ram);
 272         kfree(mp->resource.diag_ram);
 273         release_resource(mp->resource.module);
 274         kfree(mp->resource.module);
 275         kfree(mp);
 276         kfree(mtd);
 277 }
 278
 279
 280 static int __init ms02nv_init(void)
 281 {
 282         volatile u32 *csr;
 283         uint stride = 0;
 284         int count = 0;
 285         int i;
 286
 287         switch (mips_machtype) {
 288         case MACH_DS5000_200:
 289                 csr = (volatile u32 *)CKSEG1ADDR(KN02_SLOT_BASE + KN02_CSR);
 290                 if (*csr & KN02_CSR_BNK32M)
 291                         stride = 2;
 292                 break;
 293         case MACH_DS5000_2X0:
 294         case MACH_DS5900:
 295                 csr = (volatile u32 *)CKSEG1ADDR(KN03_SLOT_BASE + IOASIC_MCR);
 296                 if (*csr & KN03_MCR_BNK32M)
 297                         stride = 2;
 298                 break;
 299         default:
 300                 return -ENODEV;
 301                 break;
 302         }
 303
 304         for (i = 0; i < ARRAY_SIZE(ms02nv_addrs); i++)
 305                 if (!ms02nv_init_one(ms02nv_addrs[i] << stride))
 306                         count++;
 307
 308         return (count > 0) ? 0 : -ENODEV;
 309 }
 310
 311 static void __exit ms02nv_cleanup(void)
 312 {
 313         while (root_ms02nv_mtd)
 314                 ms02nv_remove_one();
 315 }
 316
 317
 318 module_init(ms02nv_init);
 319 module_exit(ms02nv_cleanup);