drivers/mtd/maps/latch-addr-flash.c

   1 /*
   2  * Interface for NOR flash driver whose high address lines are latched
   3  *
   4  * Copyright © 2000 Nicolas Pitre <nico@cam.org>
   5  * Copyright © 2005-2008 Analog Devices Inc.
   6  * Copyright © 2008 MontaVista Software, Inc. <source@mvista.com>
   7  *
   8  * This file is licensed under the terms of the GNU General Public License
   9  * version 2. This program is licensed "as is" without any warranty of any
  10  * kind, whether express or implied.
  11  */
  12
  13 #include <linux/init.h>
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/mtd/mtd.h>
  17 #include <linux/mtd/map.h>
  18 #include <linux/mtd/partitions.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/mtd/latch-addr-flash.h>
  21 #include <linux/slab.h>
  22
  23 #define DRIVER_NAME "latch-addr-flash"
  24
  25 struct latch_addr_flash_info {
  26         struct mtd_info         *mtd;
  27         struct map_info         map;
  28         struct resource         *res;
  29
  30         void                    (*set_window)(unsigned long offset, void *data);
  31         void                    *data;
  32
  33         /* cache; could be found out of res */
  34         unsigned long           win_mask;
  35
  36         int                     nr_parts;
  37         struct mtd_partition    *parts;
  38
  39         spinlock_t              lock;
  40 };
  41
  42 static map_word lf_read(struct map_info *map, unsigned long ofs)
  43 {
  44         struct latch_addr_flash_info *info;
  45         map_word datum;
  46
  47         info = (struct latch_addr_flash_info *)map->map_priv_1;
  48
  49         spin_lock(&info->lock);
  50
  51         info->set_window(ofs, info->data);
  52         datum = inline_map_read(map, info->win_mask & ofs);
  53
  54         spin_unlock(&info->lock);
  55
  56         return datum;
  57 }
  58
  59 static void lf_write(struct map_info *map, map_word datum, unsigned long ofs)
  60 {
  61         struct latch_addr_flash_info *info;
  62
  63         info = (struct latch_addr_flash_info *)map->map_priv_1;
  64
  65         spin_lock(&info->lock);
  66
  67         info->set_window(ofs, info->data);
  68         inline_map_write(map, datum, info->win_mask & ofs);
  69
  70         spin_unlock(&info->lock);
  71 }
  72
  73 static void lf_copy_from(struct map_info *map, void *to,
  74                 unsigned long from, ssize_t len)
  75 {
  76         struct latch_addr_flash_info *info =
  77                 (struct latch_addr_flash_info *) map->map_priv_1;
  78         unsigned n;
  79
  80         while (len > 0) {
  81                 n = info->win_mask + 1 - (from & info->win_mask);
  82                 if (n > len)
  83                         n = len;
  84
  85                 spin_lock(&info->lock);
  86
  87                 info->set_window(from, info->data);
  88                 memcpy_fromio(to, map->virt + (from & info->win_mask), n);
  89
  90                 spin_unlock(&info->lock);
  91
  92                 to += n;
  93                 from += n;
  94                 len -= n;
  95         }
  96 }
  97
  98 static char *rom_probe_types[] = { "cfi_probe", NULL };
  99
 100 static char *part_probe_types[] = { "cmdlinepart", NULL };
 101
 102 static int latch_addr_flash_remove(struct platform_device *dev)
 103 {
 104         struct latch_addr_flash_info *info;
 105         struct latch_addr_flash_data *latch_addr_data;
 106
 107         info = platform_get_drvdata(dev);
 108         if (info == NULL)
 109                 return 0;
 110         platform_set_drvdata(dev, NULL);
 111
 112         latch_addr_data = dev->dev.platform_data;
 113
 114         if (info->mtd != NULL) {
 115                 if (info->nr_parts)
 116                         kfree(info->parts);
 117                 mtd_device_unregister(info->mtd);
 118                 map_destroy(info->mtd);
 119         }
 120
 121         if (info->map.virt != NULL)
 122                 iounmap(info->map.virt);
 123
 124         if (info->res != NULL)
 125                 release_mem_region(info->res->start, resource_size(info->res));
 126
 127         kfree(info);
 128
 129         if (latch_addr_data->done)
 130                 latch_addr_data->done(latch_addr_data->data);
 131
 132         return 0;
 133 }
 134
 135 static int __devinit latch_addr_flash_probe(struct platform_device *dev)
 136 {
 137         struct latch_addr_flash_data *latch_addr_data;
 138         struct latch_addr_flash_info *info;
 139         resource_size_t win_base = dev->resource->start;
 140         resource_size_t win_size = resource_size(dev->resource);
 141         char **probe_type;
 142         int chipsel;
 143         int err;
 144
 145         latch_addr_data = dev->dev.platform_data;
 146         if (latch_addr_data == NULL)
 147                 return -ENODEV;
 148
 149         pr_notice("latch-addr platform flash device: %#llx byte "
 150                   "window at %#.8llx\n",
 151                   (unsigned long long)win_size, (unsigned long long)win_base);
 152
 153         chipsel = dev->id;
 154
 155         if (latch_addr_data->init) {
 156                 err = latch_addr_data->init(latch_addr_data->data, chipsel);
 157                 if (err != 0)
 158                         return err;
 159         }
 160
 161         info = kzalloc(sizeof(struct latch_addr_flash_info), GFP_KERNEL);
 162         if (info == NULL) {
 163                 err = -ENOMEM;
 164                 goto done;
 165         }
 166
 167         platform_set_drvdata(dev, info);
 168
 169         info->res = request_mem_region(win_base, win_size, DRIVER_NAME);
 170         if (info->res == NULL) {
 171                 dev_err(&dev->dev, "Could not reserve memory region\n");
 172                 err = -EBUSY;
 173                 goto free_info;
 174         }
 175
 176         info->map.name          = DRIVER_NAME;
 177         info->map.size          = latch_addr_data->size;
 178         info->map.bankwidth     = latch_addr_data->width;
 179
 180         info->map.phys          = NO_XIP;
 181         info->map.virt          = ioremap(win_base, win_size);
 182         if (!info->map.virt) {
 183                 err = -ENOMEM;
 184                 goto free_res;
 185         }
 186
 187         info->map.map_priv_1    = (unsigned long)info;
 188
 189         info->map.read          = lf_read;
 190         info->map.copy_from     = lf_copy_from;
 191         info->map.write         = lf_write;
 192         info->set_window        = latch_addr_data->set_window;
 193         info->data              = latch_addr_data->data;
 194         info->win_mask          = win_size - 1;
 195
 196         spin_lock_init(&info->lock);
 197
 198         for (probe_type = rom_probe_types; !info->mtd && *probe_type;
 199                 probe_type++)
 200                 info->mtd = do_map_probe(*probe_type, &info->map);
 201
 202         if (info->mtd == NULL) {
 203                 dev_err(&dev->dev, "map_probe failed\n");
 204                 err = -ENODEV;
 205                 goto iounmap;
 206         }
 207         info->mtd->owner = THIS_MODULE;
 208
 209         err = parse_mtd_partitions(info->mtd, (const char **)part_probe_types,
 210                                    &info->parts, 0);
 211         if (err > 0) {
 212                 mtd_device_register(info->mtd, info->parts, err);
 213                 return 0;
 214         }
 215         if (latch_addr_data->nr_parts) {
 216                 pr_notice("Using latch-addr-flash partition information\n");
 217                 mtd_device_register(info->mtd,
 218                                     latch_addr_data->parts,
 219                                     latch_addr_data->nr_parts);
 220                 return 0;
 221         }
 222
 223         mtd_device_register(info->mtd, NULL, 0);
 224         return 0;
 225
 226 iounmap:
 227         iounmap(info->map.virt);
 228 free_res:
 229         release_mem_region(info->res->start, resource_size(info->res));
 230 free_info:
 231         kfree(info);
 232 done:
 233         if (latch_addr_data->done)
 234                 latch_addr_data->done(latch_addr_data->data);
 235         return err;
 236 }
 237
 238 static struct platform_driver latch_addr_flash_driver = {
 239         .probe          = latch_addr_flash_probe,
 240         .remove         = __devexit_p(latch_addr_flash_remove),
 241         .driver         = {
 242                 .name   = DRIVER_NAME,
 243         },
 244 };
 245
 246 static int __init latch_addr_flash_init(void)
 247 {
 248         return platform_driver_register(&latch_addr_flash_driver);
 249 }
 250 module_init(latch_addr_flash_init);
 251
 252 static void __exit latch_addr_flash_exit(void)
 253 {
 254         platform_driver_unregister(&latch_addr_flash_driver);
 255 }
 256 module_exit(latch_addr_flash_exit);
 257
 258 MODULE_AUTHOR("David Griego <dgriego@mvista.com>");
 259 MODULE_DESCRIPTION("MTD map driver for flashes addressed physically with upper "
 260                 "address lines being set board specifically");
 261 MODULE_LICENSE("GPL v2");