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
 121         printk(KERN_INFO "SA1100 flash: CFI device at 0x%08lx, %uMiB, %d-bit\n",
 122                 phys, (unsigned)(subdev->mtd->size >> 20),
 123                 subdev->map.bankwidth * 8);
 124
 125         return 0;
 126
 127  err:
 128         sa1100_destroy_subdev(subdev);
 129  out:
 130         return ret;
 131 }
 132
 133 static void sa1100_destroy(struct sa_info *info, struct flash_platform_data *plat)
 134 {
 135         int i;
 136
 137         if (info->mtd) {
 138                 mtd_device_unregister(info->mtd);
 139                 if (info->mtd != info->subdev[0].mtd)
 140                         mtd_concat_destroy(info->mtd);
 141         }
 142
 143         for (i = info->num_subdev - 1; i >= 0; i--)
 144                 sa1100_destroy_subdev(&info->subdev[i]);
 145         kfree(info);
 146
 147         if (plat->exit)
 148                 plat->exit();
 149 }
 150
 151 static struct sa_info *sa1100_setup_mtd(struct platform_device *pdev,
 152                                         struct flash_platform_data *plat)
 153 {
 154         struct sa_info *info;
 155         int nr, size, i, ret = 0;
 156
 157         /*
 158          * Count number of devices.
 159          */
 160         for (nr = 0; ; nr++)
 161                 if (!platform_get_resource(pdev, IORESOURCE_MEM, nr))
 162                         break;
 163
 164         if (nr == 0) {
 165                 ret = -ENODEV;
 166                 goto out;
 167         }
 168
 169         size = sizeof(struct sa_info) + sizeof(struct sa_subdev_info) * nr;
 170
 171         /*
 172          * Allocate the map_info structs in one go.
 173          */
 174         info = kzalloc(size, GFP_KERNEL);
 175         if (!info) {
 176                 ret = -ENOMEM;
 177                 goto out;
 178         }
 179
 180         if (plat->init) {
 181                 ret = plat->init();
 182                 if (ret)
 183                         goto err;
 184         }
 185
 186         /*
 187          * Claim and then map the memory regions.
 188          */
 189         for (i = 0; i < nr; i++) {
 190                 struct sa_subdev_info *subdev = &info->subdev[i];
 191                 struct resource *res;
 192
 193                 res = platform_get_resource(pdev, IORESOURCE_MEM, i);
 194                 if (!res)
 195                         break;
 196
 197                 subdev->map.name = subdev->name;
 198                 sprintf(subdev->name, "%s-%d", plat->name, i);
 199                 subdev->plat = plat;
 200
 201                 ret = sa1100_probe_subdev(subdev, res);
 202                 if (ret)
 203                         break;
 204         }
 205
 206         info->num_subdev = i;
 207
 208         /*
 209          * ENXIO is special.  It means we didn't find a chip when we probed.
 210          */
 211         if (ret != 0 && !(ret == -ENXIO && info->num_subdev > 0))
 212                 goto err;
 213
 214         /*
 215          * If we found one device, don't bother with concat support.  If
 216          * we found multiple devices, use concat if we have it available,
 217          * otherwise fail.  Either way, it'll be called "sa1100".
 218          */
 219         if (info->num_subdev == 1) {
 220                 strcpy(info->subdev[0].name, plat->name);
 221                 info->mtd = info->subdev[0].mtd;
 222                 ret = 0;
 223         } else if (info->num_subdev > 1) {
 224                 struct mtd_info *cdev[nr];
 225                 /*
 226                  * We detected multiple devices.  Concatenate them together.
 227                  */
 228                 for (i = 0; i < info->num_subdev; i++)
 229                         cdev[i] = info->subdev[i].mtd;
 230
 231                 info->mtd = mtd_concat_create(cdev, info->num_subdev,
 232                                               plat->name);
 233                 if (info->mtd == NULL) {
 234                         ret = -ENXIO;
 235                         goto err;
 236                 }
 237         }
 238         info->mtd->dev.parent = &pdev->dev;
 239
 240         if (ret == 0)
 241                 return info;
 242
 243  err:
 244         sa1100_destroy(info, plat);
 245  out:
 246         return ERR_PTR(ret);
 247 }
 248
 249 static const char * const part_probes[] = { "cmdlinepart", "RedBoot", NULL };
 250
 251 static int sa1100_mtd_probe(struct platform_device *pdev)
 252 {
 253         struct flash_platform_data *plat = dev_get_platdata(&pdev->dev);
 254         struct sa_info *info;
 255         int err;
 256
 257         if (!plat)
 258                 return -ENODEV;
 259
 260         info = sa1100_setup_mtd(pdev, plat);
 261         if (IS_ERR(info)) {
 262                 err = PTR_ERR(info);
 263                 goto out;
 264         }
 265
 266         /*
 267          * Partition selection stuff.
 268          */
 269         mtd_device_parse_register(info->mtd, part_probes, NULL, plat->parts,
 270                                   plat->nr_parts);
 271
 272         platform_set_drvdata(pdev, info);
 273         err = 0;
 274
 275  out:
 276         return err;
 277 }
 278
 279 static int sa1100_mtd_remove(struct platform_device *pdev)
 280 {
 281         struct sa_info *info = platform_get_drvdata(pdev);
 282         struct flash_platform_data *plat = dev_get_platdata(&pdev->dev);
 283
 284         sa1100_destroy(info, plat);
 285
 286         return 0;
 287 }
 288
 289 static struct platform_driver sa1100_mtd_driver = {
 290         .probe          = sa1100_mtd_probe,
 291         .remove         = sa1100_mtd_remove,
 292         .driver         = {
 293                 .name   = "sa1100-mtd",
 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");