drivers/mtd/maps/dc21285.c

   1 /*
   2  * MTD map driver for flash on the DC21285 (the StrongARM-110 companion chip)
   3  *
   4  * (C) 2000  Nicolas Pitre <nico@cam.org>
   5  *
   6  * This code is GPL
   7  *
   8  * $Id: dc21285.c,v 1.24 2005/11/07 11:14:26 gleixner Exp $
   9  */
  10 #include <linux/config.h>
  11 #include <linux/module.h>
  12 #include <linux/types.h>
  13 #include <linux/kernel.h>
  14 #include <linux/init.h>
  15 #include <linux/delay.h>
  16 #include <linux/slab.h>
  17
  18 #include <linux/mtd/mtd.h>
  19 #include <linux/mtd/map.h>
  20 #include <linux/mtd/partitions.h>
  21
  22 #include <asm/io.h>
  23 #include <asm/hardware/dec21285.h>
  24 #include <asm/mach-types.h>
  25
  26
  27 static struct mtd_info *dc21285_mtd;
  28
  29 #ifdef CONFIG_ARCH_NETWINDER
  30 /*
  31  * This is really ugly, but it seams to be the only
  32  * realiable way to do it, as the cpld state machine
  33  * is unpredictible. So we have a 25us penalty per
  34  * write access.
  35  */
  36 static void nw_en_write(void)
  37 {
  38         extern spinlock_t gpio_lock;
  39         unsigned long flags;
  40
  41         /*
  42          * we want to write a bit pattern XXX1 to Xilinx to enable
  43          * the write gate, which will be open for about the next 2ms.
  44          */
  45         spin_lock_irqsave(&gpio_lock, flags);
  46         cpld_modify(1, 1);
  47         spin_unlock_irqrestore(&gpio_lock, flags);
  48
  49         /*
  50          * let the ISA bus to catch on...
  51          */
  52         udelay(25);
  53 }
  54 #else
  55 #define nw_en_write() do { } while (0)
  56 #endif
  57
  58 static map_word dc21285_read8(struct map_info *map, unsigned long ofs)
  59 {
  60         map_word val;
  61         val.x[0] = *(uint8_t*)(map->virt + ofs);
  62         return val;
  63 }
  64
  65 static map_word dc21285_read16(struct map_info *map, unsigned long ofs)
  66 {
  67         map_word val;
  68         val.x[0] = *(uint16_t*)(map->virt + ofs);
  69         return val;
  70 }
  71
  72 static map_word dc21285_read32(struct map_info *map, unsigned long ofs)
  73 {
  74         map_word val;
  75         val.x[0] = *(uint32_t*)(map->virt + ofs);
  76         return val;
  77 }
  78
  79 static void dc21285_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
  80 {
  81         memcpy(to, (void*)(map->virt + from), len);
  82 }
  83
  84 static void dc21285_write8(struct map_info *map, const map_word d, unsigned long adr)
  85 {
  86         if (machine_is_netwinder())
  87                 nw_en_write();
  88         *CSR_ROMWRITEREG = adr & 3;
  89         adr &= ~3;
  90         *(uint8_t*)(map->virt + adr) = d.x[0];
  91 }
  92
  93 static void dc21285_write16(struct map_info *map, const map_word d, unsigned long adr)
  94 {
  95         if (machine_is_netwinder())
  96                 nw_en_write();
  97         *CSR_ROMWRITEREG = adr & 3;
  98         adr &= ~3;
  99         *(uint16_t*)(map->virt + adr) = d.x[0];
 100 }
 101
 102 static void dc21285_write32(struct map_info *map, const map_word d, unsigned long adr)
 103 {
 104         if (machine_is_netwinder())
 105                 nw_en_write();
 106         *(uint32_t*)(map->virt + adr) = d.x[0];
 107 }
 108
 109 static void dc21285_copy_to_32(struct map_info *map, unsigned long to, const void *from, ssize_t len)
 110 {
 111         while (len > 0) {
 112                 map_word d;
 113                 d.x[0] = *((uint32_t*)from);
 114                 dc21285_write32(map, d, to);
 115                 from += 4;
 116                 to += 4;
 117                 len -= 4;
 118         }
 119 }
 120
 121 static void dc21285_copy_to_16(struct map_info *map, unsigned long to, const void *from, ssize_t len)
 122 {
 123         while (len > 0) {
 124                 map_word d;
 125                 d.x[0] = *((uint16_t*)from);
 126                 dc21285_write16(map, d, to);
 127                 from += 2;
 128                 to += 2;
 129                 len -= 2;
 130         }
 131 }
 132
 133 static void dc21285_copy_to_8(struct map_info *map, unsigned long to, const void *from, ssize_t len)
 134 {
 135         map_word d;
 136         d.x[0] = *((uint8_t*)from);
 137         dc21285_write8(map, d, to);
 138         from++;
 139         to++;
 140         len--;
 141 }
 142
 143 static struct map_info dc21285_map = {
 144         .name = "DC21285 flash",
 145         .phys = NO_XIP,
 146         .size = 16*1024*1024,
 147         .copy_from = dc21285_copy_from,
 148 };
 149
 150
 151 /* Partition stuff */
 152 #ifdef CONFIG_MTD_PARTITIONS
 153 static struct mtd_partition *dc21285_parts;
 154 static const char *probes[] = { "RedBoot", "cmdlinepart", NULL };
 155 #endif
 156
 157 static int __init init_dc21285(void)
 158 {
 159
 160 #ifdef CONFIG_MTD_PARTITIONS
 161         int nrparts;
 162 #endif
 163
 164         /* Determine bankwidth */
 165         switch (*CSR_SA110_CNTL & (3<<14)) {
 166                 case SA110_CNTL_ROMWIDTH_8:
 167                         dc21285_map.bankwidth = 1;
 168                         dc21285_map.read = dc21285_read8;
 169                         dc21285_map.write = dc21285_write8;
 170                         dc21285_map.copy_to = dc21285_copy_to_8;
 171                         break;
 172                 case SA110_CNTL_ROMWIDTH_16:
 173                         dc21285_map.bankwidth = 2;
 174                         dc21285_map.read = dc21285_read16;
 175                         dc21285_map.write = dc21285_write16;
 176                         dc21285_map.copy_to = dc21285_copy_to_16;
 177                         break;
 178                 case SA110_CNTL_ROMWIDTH_32:
 179                         dc21285_map.bankwidth = 4;
 180                         dc21285_map.read = dc21285_read32;
 181                         dc21285_map.write = dc21285_write32;
 182                         dc21285_map.copy_to = dc21285_copy_to_32;
 183                         break;
 184                 default:
 185                         printk (KERN_ERR "DC21285 flash: undefined bankwidth\n");
 186                         return -ENXIO;
 187         }
 188         printk (KERN_NOTICE "DC21285 flash support (%d-bit bankwidth)\n",
 189                 dc21285_map.bankwidth*8);
 190
 191         /* Let's map the flash area */
 192         dc21285_map.virt = ioremap(DC21285_FLASH, 16*1024*1024);
 193         if (!dc21285_map.virt) {
 194                 printk("Failed to ioremap\n");
 195                 return -EIO;
 196         }
 197
 198         if (machine_is_ebsa285()) {
 199                 dc21285_mtd = do_map_probe("cfi_probe", &dc21285_map);
 200         } else {
 201                 dc21285_mtd = do_map_probe("jedec_probe", &dc21285_map);
 202         }
 203
 204         if (!dc21285_mtd) {
 205                 iounmap(dc21285_map.virt);
 206                 return -ENXIO;
 207         }
 208
 209         dc21285_mtd->owner = THIS_MODULE;
 210
 211 #ifdef CONFIG_MTD_PARTITIONS
 212         nrparts = parse_mtd_partitions(dc21285_mtd, probes, &dc21285_parts, 0);
 213         if (nrparts > 0)
 214                 add_mtd_partitions(dc21285_mtd, dc21285_parts, nrparts);
 215         else
 216 #endif
 217                 add_mtd_device(dc21285_mtd);
 218
 219         if(machine_is_ebsa285()) {
 220                 /*
 221                  * Flash timing is determined with bits 19-16 of the
 222                  * CSR_SA110_CNTL.  The value is the number of wait cycles, or
 223                  * 0 for 16 cycles (the default).  Cycles are 20 ns.
 224                  * Here we use 7 for 140 ns flash chips.
 225                  */
 226                 /* access time */
 227                 *CSR_SA110_CNTL = ((*CSR_SA110_CNTL & ~0x000f0000) | (7 << 16));
 228                 /* burst time */
 229                 *CSR_SA110_CNTL = ((*CSR_SA110_CNTL & ~0x00f00000) | (7 << 20));
 230                 /* tristate time */
 231                 *CSR_SA110_CNTL = ((*CSR_SA110_CNTL & ~0x0f000000) | (7 << 24));
 232         }
 233
 234         return 0;
 235 }
 236
 237 static void __exit cleanup_dc21285(void)
 238 {
 239 #ifdef CONFIG_MTD_PARTITIONS
 240         if (dc21285_parts) {
 241                 del_mtd_partitions(dc21285_mtd);
 242                 kfree(dc21285_parts);
 243         } else
 244 #endif
 245                 del_mtd_device(dc21285_mtd);
 246
 247         map_destroy(dc21285_mtd);
 248         iounmap(dc21285_map.virt);
 249 }
 250
 251 module_init(init_dc21285);
 252 module_exit(cleanup_dc21285);
 253
 254
 255 MODULE_LICENSE("GPL");
 256 MODULE_AUTHOR("Nicolas Pitre <nico@cam.org>");
 257 MODULE_DESCRIPTION("MTD map driver for DC21285 boards");