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         spinlock_t              lock;
  37 };
  38
  39 static map_word lf_read(struct map_info *map, unsigned long ofs)
  40 {
  41         struct latch_addr_flash_info *info;
  42         map_word datum;
  43
  44         info = (struct latch_addr_flash_info *)map->map_priv_1;
  45
  46         spin_lock(&info->lock);
  47
  48         info->set_window(ofs, info->data);
  49         datum = inline_map_read(map, info->win_mask & ofs);
  50
  51         spin_unlock(&info->lock);
  52
  53         return datum;
  54 }
  55
  56 static void lf_write(struct map_info *map, map_word datum, unsigned long ofs)
  57 {
  58         struct latch_addr_flash_info *info;
  59
  60         info = (struct latch_addr_flash_info *)map->map_priv_1;
  61
  62         spin_lock(&info->lock);
  63
  64         info->set_window(ofs, info->data);
  65         inline_map_write(map, datum, info->win_mask & ofs);
  66
  67         spin_unlock(&info->lock);
  68 }
  69
  70 static void lf_copy_from(struct map_info *map, void *to,
  71                 unsigned long from, ssize_t len)
  72 {
  73         struct latch_addr_flash_info *info =
  74                 (struct latch_addr_flash_info *) map->map_priv_1;
  75         unsigned n;
  76
  77         while (len > 0) {
  78                 n = info->win_mask + 1 - (from & info->win_mask);
  79                 if (n > len)
  80                         n = len;
  81
  82                 spin_lock(&info->lock);
  83
  84                 info->set_window(from, info->data);
  85                 memcpy_fromio(to, map->virt + (from & info->win_mask), n);
  86
  87                 spin_unlock(&info->lock);
  88
  89                 to += n;
  90                 from += n;
  91                 len -= n;
  92         }
  93 }
  94
  95 static char *rom_probe_types[] = { "cfi_probe", NULL };
  96
  97 static int latch_addr_flash_remove(struct platform_device *dev)
  98 {
  99         struct latch_addr_flash_info *info;
 100         struct latch_addr_flash_data *latch_addr_data;
 101
 102         info = platform_get_drvdata(dev);
 103         if (info == NULL)
 104                 return 0;
 105
 106         latch_addr_data = dev_get_platdata(&dev->dev);
 107
 108         if (info->mtd != NULL) {
 109                 mtd_device_unregister(info->mtd);
 110                 map_destroy(info->mtd);
 111         }
 112
 113         if (info->map.virt != NULL)
 114                 iounmap(info->map.virt);
 115
 116         if (info->res != NULL)
 117                 release_mem_region(info->res->start, resource_size(info->res));
 118
 119         kfree(info);
 120
 121         if (latch_addr_data->done)
 122                 latch_addr_data->done(latch_addr_data->data);
 123
 124         return 0;
 125 }
 126
 127 static int latch_addr_flash_probe(struct platform_device *dev)
 128 {
 129         struct latch_addr_flash_data *latch_addr_data;
 130         struct latch_addr_flash_info *info;
 131         resource_size_t win_base = dev->resource->start;
 132         resource_size_t win_size = resource_size(dev->resource);
 133         char **probe_type;
 134         int chipsel;
 135         int err;
 136
 137         latch_addr_data = dev_get_platdata(&dev->dev);
 138         if (latch_addr_data == NULL)
 139                 return -ENODEV;
 140
 141         pr_notice("latch-addr platform flash device: %#llx byte "
 142                   "window at %#.8llx\n",
 143                   (unsigned long long)win_size, (unsigned long long)win_base);
 144
 145         chipsel = dev->id;
 146
 147         if (latch_addr_data->init) {
 148                 err = latch_addr_data->init(latch_addr_data->data, chipsel);
 149                 if (err != 0)
 150                         return err;
 151         }
 152
 153         info = kzalloc(sizeof(struct latch_addr_flash_info), GFP_KERNEL);
 154         if (info == NULL) {
 155                 err = -ENOMEM;
 156                 goto done;
 157         }
 158
 159         platform_set_drvdata(dev, info);
 160
 161         info->res = request_mem_region(win_base, win_size, DRIVER_NAME);
 162         if (info->res == NULL) {
 163                 dev_err(&dev->dev, "Could not reserve memory region\n");
 164                 err = -EBUSY;
 165                 goto free_info;
 166         }
 167
 168         info->map.name          = DRIVER_NAME;
 169         info->map.size          = latch_addr_data->size;
 170         info->map.bankwidth     = latch_addr_data->width;
 171
 172         info->map.phys          = NO_XIP;
 173         info->map.virt          = ioremap(win_base, win_size);
 174         if (!info->map.virt) {
 175                 err = -ENOMEM;
 176                 goto free_res;
 177         }
 178
 179         info->map.map_priv_1    = (unsigned long)info;
 180
 181         info->map.read          = lf_read;
 182         info->map.copy_from     = lf_copy_from;
 183         info->map.write         = lf_write;
 184         info->set_window        = latch_addr_data->set_window;
 185         info->data              = latch_addr_data->data;
 186         info->win_mask          = win_size - 1;
 187
 188         spin_lock_init(&info->lock);
 189
 190         for (probe_type = rom_probe_types; !info->mtd && *probe_type;
 191                 probe_type++)
 192                 info->mtd = do_map_probe(*probe_type, &info->map);
 193
 194         if (info->mtd == NULL) {
 195                 dev_err(&dev->dev, "map_probe failed\n");
 196                 err = -ENODEV;
 197                 goto iounmap;
 198         }
 199         info->mtd->owner = THIS_MODULE;
 200
 201         mtd_device_parse_register(info->mtd, NULL, NULL,
 202                                   latch_addr_data->parts,
 203                                   latch_addr_data->nr_parts);
 204         return 0;
 205
 206 iounmap:
 207         iounmap(info->map.virt);
 208 free_res:
 209         release_mem_region(info->res->start, resource_size(info->res));
 210 free_info:
 211         kfree(info);
 212 done:
 213         if (latch_addr_data->done)
 214                 latch_addr_data->done(latch_addr_data->data);
 215         return err;
 216 }
 217
 218 static struct platform_driver latch_addr_flash_driver = {
 219         .probe          = latch_addr_flash_probe,
 220         .remove         = latch_addr_flash_remove,
 221         .driver         = {
 222                 .name   = DRIVER_NAME,
 223         },
 224 };
 225
 226 module_platform_driver(latch_addr_flash_driver);
 227
 228 MODULE_AUTHOR("David Griego <dgriego@mvista.com>");
 229 MODULE_DESCRIPTION("MTD map driver for flashes addressed physically with upper "
 230                 "address lines being set board specifically");
 231 MODULE_LICENSE("GPL v2");