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 <[email protected]>
   5  * Copyright © 2005-2008 Analog Devices Inc.
   6  * Copyright © 2008 MontaVista Software, Inc. <[email protected]>
   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/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/mtd/mtd.h>
  16 #include <linux/mtd/map.h>
  17 #include <linux/mtd/partitions.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/mtd/latch-addr-flash.h>
  20 #include <linux/slab.h>
  21
  22 #define DRIVER_NAME "latch-addr-flash"
  23
  24 struct latch_addr_flash_info {
  25         struct mtd_info         *mtd;
  26         struct map_info         map;
  27         struct resource         *res;
  28
  29         void                    (*set_window)(unsigned long offset, void *data);
  30         void                    *data;
  31
  32         /* cache; could be found out of res */
  33         unsigned long           win_mask;
  34
  35         spinlock_t              lock;
  36 };
  37
  38 static map_word lf_read(struct map_info *map, unsigned long ofs)
  39 {
  40         struct latch_addr_flash_info *info;
  41         map_word datum;
  42
  43         info = (struct latch_addr_flash_info *)map->map_priv_1;
  44
  45         spin_lock(&info->lock);
  46
  47         info->set_window(ofs, info->data);
  48         datum = inline_map_read(map, info->win_mask & ofs);
  49
  50         spin_unlock(&info->lock);
  51
  52         return datum;
  53 }
  54
  55 static void lf_write(struct map_info *map, map_word datum, unsigned long ofs)
  56 {
  57         struct latch_addr_flash_info *info;
  58
  59         info = (struct latch_addr_flash_info *)map->map_priv_1;
  60
  61         spin_lock(&info->lock);
  62
  63         info->set_window(ofs, info->data);
  64         inline_map_write(map, datum, info->win_mask & ofs);
  65
  66         spin_unlock(&info->lock);
  67 }
  68
  69 static void lf_copy_from(struct map_info *map, void *to,
  70                 unsigned long from, ssize_t len)
  71 {
  72         struct latch_addr_flash_info *info =
  73                 (struct latch_addr_flash_info *) map->map_priv_1;
  74         unsigned n;
  75
  76         while (len > 0) {
  77                 n = info->win_mask + 1 - (from & info->win_mask);
  78                 if (n > len)
  79                         n = len;
  80
  81                 spin_lock(&info->lock);
  82
  83                 info->set_window(from, info->data);
  84                 memcpy_fromio(to, map->virt + (from & info->win_mask), n);
  85
  86                 spin_unlock(&info->lock);
  87
  88                 to += n;
  89                 from += n;
  90                 len -= n;
  91         }
  92 }
  93
  94 static char *rom_probe_types[] = { "cfi_probe", NULL };
  95
  96 static int latch_addr_flash_remove(struct platform_device *dev)
  97 {
  98         struct latch_addr_flash_info *info;
  99         struct latch_addr_flash_data *latch_addr_data;
 100
 101         info = platform_get_drvdata(dev);
 102         if (info == NULL)
 103                 return 0;
 104
 105         latch_addr_data = dev_get_platdata(&dev->dev);
 106
 107         if (info->mtd != NULL) {
 108                 mtd_device_unregister(info->mtd);
 109                 map_destroy(info->mtd);
 110         }
 111
 112         if (info->map.virt != NULL)
 113                 iounmap(info->map.virt);
 114
 115         if (info->res != NULL)
 116                 release_mem_region(info->res->start, resource_size(info->res));
 117
 118         kfree(info);
 119
 120         if (latch_addr_data->done)
 121                 latch_addr_data->done(latch_addr_data->data);
 122
 123         return 0;
 124 }
 125
 126 static int latch_addr_flash_probe(struct platform_device *dev)
 127 {
 128         struct latch_addr_flash_data *latch_addr_data;
 129         struct latch_addr_flash_info *info;
 130         resource_size_t win_base = dev->resource->start;
 131         resource_size_t win_size = resource_size(dev->resource);
 132         char **probe_type;
 133         int chipsel;
 134         int err;
 135
 136         latch_addr_data = dev_get_platdata(&dev->dev);
 137         if (latch_addr_data == NULL)
 138                 return -ENODEV;
 139
 140         pr_notice("latch-addr platform flash device: %#llx byte "
 141                   "window at %#.8llx\n",
 142                   (unsigned long long)win_size, (unsigned long long)win_base);
 143
 144         chipsel = dev->id;
 145
 146         if (latch_addr_data->init) {
 147                 err = latch_addr_data->init(latch_addr_data->data, chipsel);
 148                 if (err != 0)
 149                         return err;
 150         }
 151
 152         info = kzalloc(sizeof(struct latch_addr_flash_info), GFP_KERNEL);
 153         if (info == NULL) {
 154                 err = -ENOMEM;
 155                 goto done;
 156         }
 157
 158         platform_set_drvdata(dev, info);
 159
 160         info->res = request_mem_region(win_base, win_size, DRIVER_NAME);
 161         if (info->res == NULL) {
 162                 dev_err(&dev->dev, "Could not reserve memory region\n");
 163                 err = -EBUSY;
 164                 goto free_info;
 165         }
 166
 167         info->map.name          = DRIVER_NAME;
 168         info->map.size          = latch_addr_data->size;
 169         info->map.bankwidth     = latch_addr_data->width;
 170
 171         info->map.phys          = NO_XIP;
 172         info->map.virt          = ioremap(win_base, win_size);
 173         if (!info->map.virt) {
 174                 err = -ENOMEM;
 175                 goto free_res;
 176         }
 177
 178         info->map.map_priv_1    = (unsigned long)info;
 179
 180         info->map.read          = lf_read;
 181         info->map.copy_from     = lf_copy_from;
 182         info->map.write         = lf_write;
 183         info->set_window        = latch_addr_data->set_window;
 184         info->data              = latch_addr_data->data;
 185         info->win_mask          = win_size - 1;
 186
 187         spin_lock_init(&info->lock);
 188
 189         for (probe_type = rom_probe_types; !info->mtd && *probe_type;
 190                 probe_type++)
 191                 info->mtd = do_map_probe(*probe_type, &info->map);
 192
 193         if (info->mtd == NULL) {
 194                 dev_err(&dev->dev, "map_probe failed\n");
 195                 err = -ENODEV;
 196                 goto iounmap;
 197         }
 198         info->mtd->owner = THIS_MODULE;
 199
 200         mtd_device_parse_register(info->mtd, NULL, NULL,
 201                                   latch_addr_data->parts,
 202                                   latch_addr_data->nr_parts);
 203         return 0;
 204
 205 iounmap:
 206         iounmap(info->map.virt);
 207 free_res:
 208         release_mem_region(info->res->start, resource_size(info->res));
 209 free_info:
 210         kfree(info);
 211 done:
 212         if (latch_addr_data->done)
 213                 latch_addr_data->done(latch_addr_data->data);
 214         return err;
 215 }
 216
 217 static struct platform_driver latch_addr_flash_driver = {
 218         .probe          = latch_addr_flash_probe,
 219         .remove         = latch_addr_flash_remove,
 220         .driver         = {
 221                 .name   = DRIVER_NAME,
 222         },
 223 };
 224
 225 module_platform_driver(latch_addr_flash_driver);
 226
 227 MODULE_AUTHOR("David Griego <[email protected]>");
 228 MODULE_DESCRIPTION("MTD map driver for flashes addressed physically with upper "
 229                 "address lines being set board specifically");
 230 MODULE_LICENSE("GPL v2");