drivers/mtd/maps/sa1100-flash.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Flash memory access on SA11x0 based devices
   4  *
   5  * (C) 2000 Nicolas Pitre <nico@fluxnic.net>
   6  */
   7 #include <linux/module.h>
   8 #include <linux/types.h>
   9 #include <linux/ioport.h>
  10 #include <linux/kernel.h>
  11 #include <linux/init.h>
  12 #include <linux/errno.h>
  13 #include <linux/slab.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/err.h>
  16 #include <linux/io.h>
  17
  18 #include <linux/mtd/mtd.h>
  19 #include <linux/mtd/map.h>
  20 #include <linux/mtd/partitions.h>
  21 #include <linux/mtd/concat.h>
  22
  23 #include <mach/hardware.h>
  24 #include <linux/sizes.h>
  25 #include <asm/mach/flash.h>
  26
  27 struct sa_subdev_info {
  28         char name[16];
  29         struct map_info map;
  30         struct mtd_info *mtd;
  31         struct flash_platform_data *plat;
  32 };
  33
  34 struct sa_info {
  35         struct mtd_info         *mtd;
  36         int                     num_subdev;
  37         struct sa_subdev_info   subdev[];
  38 };
  39
  40 static DEFINE_SPINLOCK(sa1100_vpp_lock);
  41 static int sa1100_vpp_refcnt;
  42 static void sa1100_set_vpp(struct map_info *map, int on)
  43 {
  44         struct sa_subdev_info *subdev = container_of(map, struct sa_subdev_info, map);
  45         unsigned long flags;
  46
  47         spin_lock_irqsave(&sa1100_vpp_lock, flags);
  48         if (on) {
  49                 if (++sa1100_vpp_refcnt == 1)   /* first nested 'on' */
  50                         subdev->plat->set_vpp(1);
  51         } else {
  52                 if (--sa1100_vpp_refcnt == 0)   /* last nested 'off' */
  53                         subdev->plat->set_vpp(0);
  54         }
  55         spin_unlock_irqrestore(&sa1100_vpp_lock, flags);
  56 }
  57
  58 static void sa1100_destroy_subdev(struct sa_subdev_info *subdev)
  59 {
  60         if (subdev->mtd)
  61                 map_destroy(subdev->mtd);
  62         if (subdev->map.virt)
  63                 iounmap(subdev->map.virt);
  64         release_mem_region(subdev->map.phys, subdev->map.size);
  65 }
  66
  67 static int sa1100_probe_subdev(struct sa_subdev_info *subdev, struct resource *res)
  68 {
  69         unsigned long phys;
  70         unsigned int size;
  71         int ret;
  72
  73         phys = res->start;
  74         size = res->end - phys + 1;
  75
  76         /*
  77          * Retrieve the bankwidth from the MSC registers.
  78          * We currently only implement CS0 and CS1 here.
  79          */
  80         switch (phys) {
  81         default:
  82                 printk(KERN_WARNING "SA1100 flash: unknown base address "
  83                        "0x%08lx, assuming CS0\n", phys);
  84                 fallthrough;
  85         case SA1100_CS0_PHYS:
  86                 subdev->map.bankwidth = (MSC0 & MSC_RBW) ? 2 : 4;
  87                 break;
  88
  89         case SA1100_CS1_PHYS:
  90                 subdev->map.bankwidth = ((MSC0 >> 16) & MSC_RBW) ? 2 : 4;
  91                 break;
  92         }
  93
  94         if (!request_mem_region(phys, size, subdev->name)) {
  95                 ret = -EBUSY;
  96                 goto out;
  97         }
  98
  99         if (subdev->plat->set_vpp)
 100                 subdev->map.set_vpp = sa1100_set_vpp;
 101
 102         subdev->map.phys = phys;
 103         subdev->map.size = size;
 104         subdev->map.virt = ioremap(phys, size);
 105         if (!subdev->map.virt) {
 106                 ret = -ENOMEM;
 107                 goto err;
 108         }
 109
 110         simple_map_init(&subdev->map);
 111
 112         /*
 113          * Now let's probe for the actual flash.  Do it here since
 114          * specific machine settings might have been set above.
 115          */
 116         subdev->mtd = do_map_probe(subdev->plat->map_name, &subdev->map);
 117         if (subdev->mtd == NULL) {
 118                 ret = -ENXIO;
 119                 goto err;
 120         }
 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;
 226
 227                 cdev = kmalloc_array(nr, sizeof(*cdev), GFP_KERNEL);
 228                 if (!cdev) {
 229                         ret = -ENOMEM;
 230                         goto err;
 231                 }
 232
 233                 /*
 234                  * We detected multiple devices.  Concatenate them together.
 235                  */
 236                 for (i = 0; i < info->num_subdev; i++)
 237                         cdev[i] = info->subdev[i].mtd;
 238
 239                 info->mtd = mtd_concat_create(cdev, info->num_subdev,
 240                                               plat->name);
 241                 kfree(cdev);
 242                 if (info->mtd == NULL) {
 243                         ret = -ENXIO;
 244                         goto err;
 245                 }
 246         }
 247         info->mtd->dev.parent = &pdev->dev;
 248
 249         if (ret == 0)
 250                 return info;
 251
 252  err:
 253         sa1100_destroy(info, plat);
 254  out:
 255         return ERR_PTR(ret);
 256 }
 257
 258 static const char * const part_probes[] = { "cmdlinepart", "RedBoot", NULL };
 259
 260 static int sa1100_mtd_probe(struct platform_device *pdev)
 261 {
 262         struct flash_platform_data *plat = dev_get_platdata(&pdev->dev);
 263         struct sa_info *info;
 264         int err;
 265
 266         if (!plat)
 267                 return -ENODEV;
 268
 269         info = sa1100_setup_mtd(pdev, plat);
 270         if (IS_ERR(info)) {
 271                 err = PTR_ERR(info);
 272                 goto out;
 273         }
 274
 275         /*
 276          * Partition selection stuff.
 277          */
 278         mtd_device_parse_register(info->mtd, part_probes, NULL, plat->parts,
 279                                   plat->nr_parts);
 280
 281         platform_set_drvdata(pdev, info);
 282         err = 0;
 283
 284  out:
 285         return err;
 286 }
 287
 288 static int sa1100_mtd_remove(struct platform_device *pdev)
 289 {
 290         struct sa_info *info = platform_get_drvdata(pdev);
 291         struct flash_platform_data *plat = dev_get_platdata(&pdev->dev);
 292
 293         sa1100_destroy(info, plat);
 294
 295         return 0;
 296 }
 297
 298 static struct platform_driver sa1100_mtd_driver = {
 299         .probe          = sa1100_mtd_probe,
 300         .remove         = sa1100_mtd_remove,
 301         .driver         = {
 302                 .name   = "sa1100-mtd",
 303         },
 304 };
 305
 306 module_platform_driver(sa1100_mtd_driver);
 307
 308 MODULE_AUTHOR("Nicolas Pitre");
 309 MODULE_DESCRIPTION("SA1100 CFI map driver");
 310 MODULE_LICENSE("GPL");
 311 MODULE_ALIAS("platform:sa1100-mtd");