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 1.20 2004/07/12 22:38:29 dwmw2 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
  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         extern spinlock_t gpio_lock;
  37         unsigned long flags;
  38
  39         /*
  40          * we want to write a bit pattern XXX1 to Xilinx to enable
  41          * the write gate, which will be open for about the next 2ms.
  42          */
  43         spin_lock_irqsave(&gpio_lock, flags);
  44         cpld_modify(1, 1);
  45         spin_unlock_irqrestore(&gpio_lock, flags);
  46
  47         /*
  48          * let the ISA bus to catch on...
  49          */
  50         udelay(25);
  51 }
  52 #else
  53 #define nw_en_write() do { } while (0)
  54 #endif
  55
  56 static map_word dc21285_read8(struct map_info *map, unsigned long ofs)
  57 {
  58         return *(uint8_t*)(map->map_priv_1 + ofs);
  59 }
  60
  61 static map_word dc21285_read16(struct map_info *map, unsigned long ofs)
  62 {
  63         return *(uint16_t*)(map->map_priv_1 + ofs);
  64 }
  65
  66 static map_word dc21285_read32(struct map_info *map, unsigned long ofs)
  67 {
  68         return *(uint32_t*)(map->map_priv_1 + ofs);
  69 }
  70
  71 static void dc21285_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
  72 {
  73         memcpy(to, (void*)(map->map_priv_1 + from), len);
  74 }
  75
  76 static void dc21285_write(struct map_info *map, map_word d, unsigned long adr)
  77 {
  78         if (machine_is_netwinder())
  79                 nw_en_write();
  80         *CSR_ROMWRITEREG = adr & 3;
  81         adr &= ~3;
  82         *(uint8_t*)(map->map_priv_1 + adr) = d.x[0];
  83 }
  84
  85 static void dc21285_write16(struct map_info *map, map_word d, unsigned long adr)
  86 {
  87         if (machine_is_netwinder())
  88                 nw_en_write();
  89         *CSR_ROMWRITEREG = adr & 3;
  90         adr &= ~3;
  91         *(uint16_t*)(map->map_priv_1 + adr) = d.x[0];
  92 }
  93
  94 static void dc21285_write32(struct map_info *map, map_word d, unsigned long adr)
  95 {
  96         if (machine_is_netwinder())
  97                 nw_en_write();
  98         *(uint32_t*)(map->map_priv_1 + adr) = d.x[0];
  99 }
 100
 101 static void dc21285_copy_to_32(struct map_info *map, unsigned long to, const void *from, ssize_t len)
 102 {
 103         while (len > 0) {
 104                 uint32_t d = *((uint32_t*)from)++;
 105                 dc21285_write32(map, d, to);
 106                 to += 4;
 107                 len -= 4;
 108         }
 109 }
 110
 111 static void dc21285_copy_to_16(struct map_info *map, unsigned long to, const void *from, ssize_t len)
 112 {
 113         while (len > 0) {
 114                 uint16_t d = *((uint16_t*)from)++;
 115                 dc21285_write16(map, d, to);
 116                 to += 2;
 117                 len -= 2;
 118         }
 119 }
 120
 121 static void dc21285_copy_to_8(struct map_info *map, unsigned long to, const void *from, ssize_t len)
 122 {
 123         uint8_t d = *((uint8_t*)from)++;
 124         dc21285_write8(map, d, to);
 125         to++;
 126         len--;
 127 }
 128
 129 static struct map_info dc21285_map = {
 130         .name = "DC21285 flash",
 131         .phys = NO_XIP,
 132         .size = 16*1024*1024,
 133         .copy_from = dc21285_copy_from,
 134 };
 135
 136
 137 /* Partition stuff */
 138 static struct mtd_partition *dc21285_parts;
 139 #ifdef CONFIG_MTD_PARTITIONS
 140 static const char *probes[] = { "RedBoot", "cmdlinepart", NULL };
 141 #endif
 142
 143 static int __init init_dc21285(void)
 144 {
 145
 146 #ifdef CONFIG_MTD_PARTITIONS
 147         int nrparts;
 148 #endif
 149
 150         /* Determine bankwidth */
 151         switch (*CSR_SA110_CNTL & (3<<14)) {
 152                 case SA110_CNTL_ROMWIDTH_8:
 153                         dc21285_map.bankwidth = 1;
 154                         dc21285_map.read = dc21285_read8;
 155                         dc21285_map.write = dc21285_write8;
 156                         dc21285_map.copy_to = dc21285_copy_to_8;
 157                         break;
 158                 case SA110_CNTL_ROMWIDTH_16:
 159                         dc21285_map.bankwidth = 2;
 160                         dc21285_map.read = dc21285_read16;
 161                         dc21285_map.write = dc21285_write16;
 162                         dc21285_map.copy_to = dc21285_copy_to_16;
 163                         break;
 164                 case SA110_CNTL_ROMWIDTH_32:
 165                         dc21285_map.bankwidth = 4;
 166                         break;
 167                         dc21285_map.read = dc21285_read32;
 168                         dc21285_map.write = dc21285_write32;
 169                         dc21285_map.copy_to = dc21285_copy_to_32;
 170                 default:
 171                         printk (KERN_ERR "DC21285 flash: undefined bankwidth\n");
 172                         return -ENXIO;
 173         }
 174         printk (KERN_NOTICE "DC21285 flash support (%d-bit bankwidth)\n",
 175                 dc21285_map.bankwidth*8);
 176
 177         /* Let's map the flash area */
 178         dc21285_map.map_priv_1 = (unsigned long)ioremap(DC21285_FLASH, 16*1024*1024);
 179         if (!dc21285_map.map_priv_1) {
 180                 printk("Failed to ioremap\n");
 181                 return -EIO;
 182         }
 183
 184         if (machine_is_ebsa285()) {
 185                 dc21285_mtd = do_map_probe("cfi_probe", &dc21285_map);
 186         } else {
 187                 dc21285_mtd = do_map_probe("jedec_probe", &dc21285_map);
 188         }
 189
 190         if (!dc21285_mtd) {
 191                 iounmap((void *)dc21285_map.map_priv_1);
 192                 return -ENXIO;
 193         }
 194
 195         dc21285_mtd->owner = THIS_MODULE;
 196
 197 #ifdef CONFIG_MTD_PARTITIONS
 198         nrparts = parse_mtd_partitions(dc21285_mtd, probes, &dc21285_parts, (void *)0);
 199         if (nrparts > 0)
 200                 add_mtd_partitions(dc21285_mtd, dc21285_parts, nrparts);
 201         else
 202 #endif
 203                 add_mtd_device(dc21285_mtd);
 204
 205         if(machine_is_ebsa285()) {
 206                 /*
 207                  * Flash timing is determined with bits 19-16 of the
 208                  * CSR_SA110_CNTL.  The value is the number of wait cycles, or
 209                  * 0 for 16 cycles (the default).  Cycles are 20 ns.
 210                  * Here we use 7 for 140 ns flash chips.
 211                  */
 212                 /* access time */
 213                 *CSR_SA110_CNTL = ((*CSR_SA110_CNTL & ~0x000f0000) | (7 << 16));
 214                 /* burst time */
 215                 *CSR_SA110_CNTL = ((*CSR_SA110_CNTL & ~0x00f00000) | (7 << 20));
 216                 /* tristate time */
 217                 *CSR_SA110_CNTL = ((*CSR_SA110_CNTL & ~0x0f000000) | (7 << 24));
 218         }
 219
 220         return 0;
 221 }
 222
 223 static void __exit cleanup_dc21285(void)
 224 {
 225 #ifdef CONFIG_MTD_PARTITIONS
 226         if (dc21285_parts) {
 227                 del_mtd_partitions(dc21285_mtd);
 228                 kfree(dc21285_parts);
 229         } else
 230 #endif
 231                 del_mtd_device(dc21285_mtd);
 232
 233         map_destroy(dc21285_mtd);
 234         iounmap((void *)dc21285_map.map_priv_1);
 235 }
 236
 237 module_init(init_dc21285);
 238 module_exit(cleanup_dc21285);
 239
 240
 241 MODULE_LICENSE("GPL");
 242 MODULE_AUTHOR("Nicolas Pitre <nico@cam.org>");
 243 MODULE_DESCRIPTION("MTD map driver for DC21285 boards");