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