drivers/mtd/maps/sa1100-flash.c

   1 /*
   2  * Flash memory access on SA11x0 based devices
   3  *
   4  * (C) 2000 Nicolas Pitre <nico@fluxnic.net>
   5  */
   6 #include <linux/module.h>
   7 #include <linux/types.h>
   8 #include <linux/ioport.h>
   9 #include <linux/kernel.h>
  10 #include <linux/init.h>
  11 #include <linux/errno.h>
  12 #include <linux/slab.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/err.h>
  15 #include <linux/io.h>
  16
  17 #include <linux/mtd/mtd.h>
  18 #include <linux/mtd/map.h>
  19 #include <linux/mtd/partitions.h>
  20 #include <linux/mtd/concat.h>
  21
  22 #include <mach/hardware.h>
  23 #include <asm/sizes.h>
  24 #include <asm/mach/flash.h>
  25
  26 struct sa_subdev_info {
  27         char name[16];
  28         struct map_info map;
  29         struct mtd_info *mtd;
  30         struct flash_platform_data *plat;
  31 };
  32
  33 struct sa_info {
  34         struct mtd_info         *mtd;
  35         int                     num_subdev;
  36         struct sa_subdev_info   subdev[0];
  37 };
  38
  39 static DEFINE_SPINLOCK(sa1100_vpp_lock);
  40 static int sa1100_vpp_refcnt;
  41 static void sa1100_set_vpp(struct map_info *map, int on)
  42 {
  43         struct sa_subdev_info *subdev = container_of(map, struct sa_subdev_info, map);
  44         unsigned long flags;
  45
  46         spin_lock_irqsave(&sa1100_vpp_lock, flags);
  47         if (on) {
  48                 if (++sa1100_vpp_refcnt == 1)   /* first nested 'on' */
  49                         subdev->plat->set_vpp(1);
  50         } else {
  51                 if (--sa1100_vpp_refcnt == 0)   /* last nested 'off' */
  52                         subdev->plat->set_vpp(0);
  53         }
  54         spin_unlock_irqrestore(&sa1100_vpp_lock, flags);
  55 }
  56
  57 static void sa1100_destroy_subdev(struct sa_subdev_info *subdev)
  58 {
  59         if (subdev->mtd)
  60                 map_destroy(subdev->mtd);
  61         if (subdev->map.virt)
  62                 iounmap(subdev->map.virt);
  63         release_mem_region(subdev->map.phys, subdev->map.size);
  64 }
  65
  66 static int sa1100_probe_subdev(struct sa_subdev_info *subdev, struct resource *res)
  67 {
  68         unsigned long phys;
  69         unsigned int size;
  70         int ret;
  71
  72         phys = res->start;
  73         size = res->end - phys + 1;
  74
  75         /*
  76          * Retrieve the bankwidth from the MSC registers.
  77          * We currently only implement CS0 and CS1 here.
  78          */
  79         switch (phys) {
  80         default:
  81                 printk(KERN_WARNING "SA1100 flash: unknown base address "
  82                        "0x%08lx, assuming CS0\n", phys);
  83
  84         case SA1100_CS0_PHYS:
  85                 subdev->map.bankwidth = (MSC0 & MSC_RBW) ? 2 : 4;
  86                 break;
  87
  88         case SA1100_CS1_PHYS:
  89                 subdev->map.bankwidth = ((MSC0 >> 16) & MSC_RBW) ? 2 : 4;
  90                 break;
  91         }
  92
  93         if (!request_mem_region(phys, size, subdev->name)) {
  94                 ret = -EBUSY;
  95                 goto out;
  96         }
  97
  98         if (subdev->plat->set_vpp)
  99                 subdev->map.set_vpp = sa1100_set_vpp;
 100
 101         subdev->map.phys = phys;
 102         subdev->map.size = size;
 103         subdev->map.virt = ioremap(phys, size);
 104         if (!subdev->map.virt) {
 105                 ret = -ENOMEM;
 106                 goto err;
 107         }
 108
 109         simple_map_init(&subdev->map);
 110
 111         /*
 112          * Now let's probe for the actual flash.  Do it here since
 113          * specific machine settings might have been set above.
 114          */
 115         subdev->mtd = do_map_probe(subdev->plat->map_name, &subdev->map);
 116         if (subdev->mtd == NULL) {
 117                 ret = -ENXIO;
 118                 goto err;
 119         }
 120         subdev->mtd->owner = THIS_MODULE;
 121
 122         printk(KERN_INFO "SA1100 flash: CFI device at 0x%08lx, %uMiB, %d-bit\n",
 123                 phys, (unsigned)(subdev->mtd->size >> 20),
 124                 subdev->map.bankwidth * 8);
 125
 126         return 0;
 127
 128  err:
 129         sa1100_destroy_subdev(subdev);
 130  out:
 131         return ret;
 132 }
 133
 134 static void sa1100_destroy(struct sa_info *info, struct flash_platform_data *plat)
 135 {
 136         int i;
 137
 138         if (info->mtd) {
 139                 mtd_device_unregister(info->mtd);
 140                 if (info->mtd != info->subdev[0].mtd)
 141                         mtd_concat_destroy(info->mtd);
 142         }
 143
 144         for (i = info->num_subdev - 1; i >= 0; i--)
 145                 sa1100_destroy_subdev(&info->subdev[i]);
 146         kfree(info);
 147
 148         if (plat->exit)
 149                 plat->exit();
 150 }
 151
 152 static struct sa_info *sa1100_setup_mtd(struct platform_device *pdev,
 153                                         struct flash_platform_data *plat)
 154 {
 155         struct sa_info *info;
 156         int nr, size, i, ret = 0;
 157
 158         /*
 159          * Count number of devices.
 160          */
 161         for (nr = 0; ; nr++)
 162                 if (!platform_get_resource(pdev, IORESOURCE_MEM, nr))
 163                         break;
 164
 165         if (nr == 0) {
 166                 ret = -ENODEV;
 167                 goto out;
 168         }
 169
 170         size = sizeof(struct sa_info) + sizeof(struct sa_subdev_info) * nr;
 171
 172         /*
 173          * Allocate the map_info structs in one go.
 174          */
 175         info = kzalloc(size, GFP_KERNEL);
 176         if (!info) {
 177                 ret = -ENOMEM;
 178                 goto out;
 179         }
 180
 181         if (plat->init) {
 182                 ret = plat->init();
 183                 if (ret)
 184                         goto err;
 185         }
 186
 187         /*
 188          * Claim and then map the memory regions.
 189          */
 190         for (i = 0; i < nr; i++) {
 191                 struct sa_subdev_info *subdev = &info->subdev[i];
 192                 struct resource *res;
 193
 194                 res = platform_get_resource(pdev, IORESOURCE_MEM, i);
 195                 if (!res)
 196                         break;
 197
 198                 subdev->map.name = subdev->name;
 199                 sprintf(subdev->name, "%s-%d", plat->name, i);
 200                 subdev->plat = plat;
 201
 202                 ret = sa1100_probe_subdev(subdev, res);
 203                 if (ret)
 204                         break;
 205         }
 206
 207         info->num_subdev = i;
 208
 209         /*
 210          * ENXIO is special.  It means we didn't find a chip when we probed.
 211          */
 212         if (ret != 0 && !(ret == -ENXIO && info->num_subdev > 0))
 213                 goto err;
 214
 215         /*
 216          * If we found one device, don't bother with concat support.  If
 217          * we found multiple devices, use concat if we have it available,
 218          * otherwise fail.  Either way, it'll be called "sa1100".
 219          */
 220         if (info->num_subdev == 1) {
 221                 strcpy(info->subdev[0].name, plat->name);
 222                 info->mtd = info->subdev[0].mtd;
 223                 ret = 0;
 224         } else if (info->num_subdev > 1) {
 225                 struct mtd_info *cdev[nr];
 226                 /*
 227                  * We detected multiple devices.  Concatenate them together.
 228                  */
 229                 for (i = 0; i < info->num_subdev; i++)
 230                         cdev[i] = info->subdev[i].mtd;
 231
 232                 info->mtd = mtd_concat_create(cdev, info->num_subdev,
 233                                               plat->name);
 234                 if (info->mtd == NULL)
 235                         ret = -ENXIO;
 236         }
 237
 238         if (ret == 0)
 239                 return info;
 240
 241  err:
 242         sa1100_destroy(info, plat);
 243  out:
 244         return ERR_PTR(ret);
 245 }
 246
 247 static const char *part_probes[] = { "cmdlinepart", "RedBoot", NULL };
 248
 249 static int sa1100_mtd_probe(struct platform_device *pdev)
 250 {
 251         struct flash_platform_data *plat = pdev->dev.platform_data;
 252         struct sa_info *info;
 253         int err;
 254
 255         if (!plat)
 256                 return -ENODEV;
 257
 258         info = sa1100_setup_mtd(pdev, plat);
 259         if (IS_ERR(info)) {
 260                 err = PTR_ERR(info);
 261                 goto out;
 262         }
 263
 264         /*
 265          * Partition selection stuff.
 266          */
 267         mtd_device_parse_register(info->mtd, part_probes, NULL, plat->parts,
 268                                   plat->nr_parts);
 269
 270         platform_set_drvdata(pdev, info);
 271         err = 0;
 272
 273  out:
 274         return err;
 275 }
 276
 277 static int __exit sa1100_mtd_remove(struct platform_device *pdev)
 278 {
 279         struct sa_info *info = platform_get_drvdata(pdev);
 280         struct flash_platform_data *plat = pdev->dev.platform_data;
 281
 282         platform_set_drvdata(pdev, NULL);
 283         sa1100_destroy(info, plat);
 284
 285         return 0;
 286 }
 287
 288 static struct platform_driver sa1100_mtd_driver = {
 289         .probe          = sa1100_mtd_probe,
 290         .remove         = __exit_p(sa1100_mtd_remove),
 291         .driver         = {
 292                 .name   = "sa1100-mtd",
 293                 .owner  = THIS_MODULE,
 294         },
 295 };
 296
 297 module_platform_driver(sa1100_mtd_driver);
 298
 299 MODULE_AUTHOR("Nicolas Pitre");
 300 MODULE_DESCRIPTION("SA1100 CFI map driver");
 301 MODULE_LICENSE("GPL");
 302 MODULE_ALIAS("platform:sa1100-mtd");