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