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 (mtd_has_partitions()) {
 116                         if (info->nr_parts) {
 117                                 del_mtd_partitions(info->mtd);
 118                                 kfree(info->parts);
 119                         } else if (latch_addr_data->nr_parts) {
 120                                 del_mtd_partitions(info->mtd);
 121                         } else {
 122                                 del_mtd_device(info->mtd);
 123                         }
 124                 } else {
 125                         del_mtd_device(info->mtd);
 126                 }
 127                 map_destroy(info->mtd);
 128         }
 129
 130         if (info->map.virt != NULL)
 131                 iounmap(info->map.virt);
 132
 133         if (info->res != NULL)
 134                 release_mem_region(info->res->start, resource_size(info->res));
 135
 136         kfree(info);
 137
 138         if (latch_addr_data->done)
 139                 latch_addr_data->done(latch_addr_data->data);
 140
 141         return 0;
 142 }
 143
 144 static int __devinit latch_addr_flash_probe(struct platform_device *dev)
 145 {
 146         struct latch_addr_flash_data *latch_addr_data;
 147         struct latch_addr_flash_info *info;
 148         resource_size_t win_base = dev->resource->start;
 149         resource_size_t win_size = resource_size(dev->resource);
 150         char **probe_type;
 151         int chipsel;
 152         int err;
 153
 154         latch_addr_data = dev->dev.platform_data;
 155         if (latch_addr_data == NULL)
 156                 return -ENODEV;
 157
 158         pr_notice("latch-addr platform flash device: %#llx byte "
 159                   "window at %#.8llx\n",
 160                   (unsigned long long)win_size, (unsigned long long)win_base);
 161
 162         chipsel = dev->id;
 163
 164         if (latch_addr_data->init) {
 165                 err = latch_addr_data->init(latch_addr_data->data, chipsel);
 166                 if (err != 0)
 167                         return err;
 168         }
 169
 170         info = kzalloc(sizeof(struct latch_addr_flash_info), GFP_KERNEL);
 171         if (info == NULL) {
 172                 err = -ENOMEM;
 173                 goto done;
 174         }
 175
 176         platform_set_drvdata(dev, info);
 177
 178         info->res = request_mem_region(win_base, win_size, DRIVER_NAME);
 179         if (info->res == NULL) {
 180                 dev_err(&dev->dev, "Could not reserve memory region\n");
 181                 err = -EBUSY;
 182                 goto free_info;
 183         }
 184
 185         info->map.name          = DRIVER_NAME;
 186         info->map.size          = latch_addr_data->size;
 187         info->map.bankwidth     = latch_addr_data->width;
 188
 189         info->map.phys          = NO_XIP;
 190         info->map.virt          = ioremap(win_base, win_size);
 191         if (!info->map.virt) {
 192                 err = -ENOMEM;
 193                 goto free_res;
 194         }
 195
 196         info->map.map_priv_1    = (unsigned long)info;
 197
 198         info->map.read          = lf_read;
 199         info->map.copy_from     = lf_copy_from;
 200         info->map.write         = lf_write;
 201         info->set_window        = latch_addr_data->set_window;
 202         info->data              = latch_addr_data->data;
 203         info->win_mask          = win_size - 1;
 204
 205         spin_lock_init(&info->lock);
 206
 207         for (probe_type = rom_probe_types; !info->mtd && *probe_type;
 208                 probe_type++)
 209                 info->mtd = do_map_probe(*probe_type, &info->map);
 210
 211         if (info->mtd == NULL) {
 212                 dev_err(&dev->dev, "map_probe failed\n");
 213                 err = -ENODEV;
 214                 goto iounmap;
 215         }
 216         info->mtd->owner = THIS_MODULE;
 217
 218         if (mtd_has_partitions()) {
 219
 220                 err = parse_mtd_partitions(info->mtd,
 221                                            (const char **)part_probe_types,
 222                                            &info->parts, 0);
 223                 if (err > 0) {
 224                         add_mtd_partitions(info->mtd, info->parts, err);
 225                         return 0;
 226                 }
 227                 if (latch_addr_data->nr_parts) {
 228                         pr_notice("Using latch-addr-flash partition information\n");
 229                         add_mtd_partitions(info->mtd, latch_addr_data->parts,
 230                                         latch_addr_data->nr_parts);
 231                         return 0;
 232                 }
 233         }
 234         add_mtd_device(info->mtd);
 235         return 0;
 236
 237 iounmap:
 238         iounmap(info->map.virt);
 239 free_res:
 240         release_mem_region(info->res->start, resource_size(info->res));
 241 free_info:
 242         kfree(info);
 243 done:
 244         if (latch_addr_data->done)
 245                 latch_addr_data->done(latch_addr_data->data);
 246         return err;
 247 }
 248
 249 static struct platform_driver latch_addr_flash_driver = {
 250         .probe          = latch_addr_flash_probe,
 251         .remove         = __devexit_p(latch_addr_flash_remove),
 252         .driver         = {
 253                 .name   = DRIVER_NAME,
 254         },
 255 };
 256
 257 static int __init latch_addr_flash_init(void)
 258 {
 259         return platform_driver_register(&latch_addr_flash_driver);
 260 }
 261 module_init(latch_addr_flash_init);
 262
 263 static void __exit latch_addr_flash_exit(void)
 264 {
 265         platform_driver_unregister(&latch_addr_flash_driver);
 266 }
 267 module_exit(latch_addr_flash_exit);
 268
 269 MODULE_AUTHOR("David Griego <dgriego@mvista.com>");
 270 MODULE_DESCRIPTION("MTD map driver for flashes addressed physically with upper "
 271                 "address lines being set board specifically");
 272 MODULE_LICENSE("GPL v2");