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 1.22 2004/11/01 13:39:21 rmk 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                 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                 to += 2;
 127                 len -= 2;
 128         }
 129 }
 130
 131 static void dc21285_copy_to_8(struct map_info *map, unsigned long to, const void *from, ssize_t len)
 132 {
 133         map_word d;
 134         d.x[0] = *((uint8_t*)from)++;
 135         dc21285_write8(map, d, to);
 136         to++;
 137         len--;
 138 }
 139
 140 static struct map_info dc21285_map = {
 141         .name = "DC21285 flash",
 142         .phys = NO_XIP,
 143         .size = 16*1024*1024,
 144         .copy_from = dc21285_copy_from,
 145 };
 146
 147
 148 /* Partition stuff */
 149 #ifdef CONFIG_MTD_PARTITIONS
 150 static struct mtd_partition *dc21285_parts;
 151 static const char *probes[] = { "RedBoot", "cmdlinepart", NULL };
 152 #endif
 153
 154 static int __init init_dc21285(void)
 155 {
 156
 157 #ifdef CONFIG_MTD_PARTITIONS
 158         int nrparts;
 159 #endif
 160
 161         /* Determine bankwidth */
 162         switch (*CSR_SA110_CNTL & (3<<14)) {
 163                 case SA110_CNTL_ROMWIDTH_8:
 164                         dc21285_map.bankwidth = 1;
 165                         dc21285_map.read = dc21285_read8;
 166                         dc21285_map.write = dc21285_write8;
 167                         dc21285_map.copy_to = dc21285_copy_to_8;
 168                         break;
 169                 case SA110_CNTL_ROMWIDTH_16:
 170                         dc21285_map.bankwidth = 2;
 171                         dc21285_map.read = dc21285_read16;
 172                         dc21285_map.write = dc21285_write16;
 173                         dc21285_map.copy_to = dc21285_copy_to_16;
 174                         break;
 175                 case SA110_CNTL_ROMWIDTH_32:
 176                         dc21285_map.bankwidth = 4;
 177                         dc21285_map.read = dc21285_read32;
 178                         dc21285_map.write = dc21285_write32;
 179                         dc21285_map.copy_to = dc21285_copy_to_32;
 180                         break;
 181                 default:
 182                         printk (KERN_ERR "DC21285 flash: undefined bankwidth\n");
 183                         return -ENXIO;
 184         }
 185         printk (KERN_NOTICE "DC21285 flash support (%d-bit bankwidth)\n",
 186                 dc21285_map.bankwidth*8);
 187
 188         /* Let's map the flash area */
 189         dc21285_map.virt = ioremap(DC21285_FLASH, 16*1024*1024);
 190         if (!dc21285_map.virt) {
 191                 printk("Failed to ioremap\n");
 192                 return -EIO;
 193         }
 194
 195         if (machine_is_ebsa285()) {
 196                 dc21285_mtd = do_map_probe("cfi_probe", &dc21285_map);
 197         } else {
 198                 dc21285_mtd = do_map_probe("jedec_probe", &dc21285_map);
 199         }
 200
 201         if (!dc21285_mtd) {
 202                 iounmap(dc21285_map.virt);
 203                 return -ENXIO;
 204         }
 205
 206         dc21285_mtd->owner = THIS_MODULE;
 207
 208 #ifdef CONFIG_MTD_PARTITIONS
 209         nrparts = parse_mtd_partitions(dc21285_mtd, probes, &dc21285_parts, 0);
 210         if (nrparts > 0)
 211                 add_mtd_partitions(dc21285_mtd, dc21285_parts, nrparts);
 212         else
 213 #endif
 214                 add_mtd_device(dc21285_mtd);
 215
 216         if(machine_is_ebsa285()) {
 217                 /*
 218                  * Flash timing is determined with bits 19-16 of the
 219                  * CSR_SA110_CNTL.  The value is the number of wait cycles, or
 220                  * 0 for 16 cycles (the default).  Cycles are 20 ns.
 221                  * Here we use 7 for 140 ns flash chips.
 222                  */
 223                 /* access time */
 224                 *CSR_SA110_CNTL = ((*CSR_SA110_CNTL & ~0x000f0000) | (7 << 16));
 225                 /* burst time */
 226                 *CSR_SA110_CNTL = ((*CSR_SA110_CNTL & ~0x00f00000) | (7 << 20));
 227                 /* tristate time */
 228                 *CSR_SA110_CNTL = ((*CSR_SA110_CNTL & ~0x0f000000) | (7 << 24));
 229         }
 230
 231         return 0;
 232 }
 233
 234 static void __exit cleanup_dc21285(void)
 235 {
 236 #ifdef CONFIG_MTD_PARTITIONS
 237         if (dc21285_parts) {
 238                 del_mtd_partitions(dc21285_mtd);
 239                 kfree(dc21285_parts);
 240         } else
 241 #endif
 242                 del_mtd_device(dc21285_mtd);
 243
 244         map_destroy(dc21285_mtd);
 245         iounmap(dc21285_map.virt);
 246 }
 247
 248 module_init(init_dc21285);
 249 module_exit(cleanup_dc21285);
 250
 251
 252 MODULE_LICENSE("GPL");
 253 MODULE_AUTHOR("Nicolas Pitre <nico@cam.org>");
 254 MODULE_DESCRIPTION("MTD map driver for DC21285 boards");