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 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 to += 4; 115 len -= 4; 116 } 117 } 118 119 static void dc21285_copy_to_16(struct map_info *map, unsigned long to, const void *from, ssize_t len) 120 { 121 while (len > 0) { 122 map_word d; 123 d.x[0] = *((uint16_t*)from)++; 124 dc21285_write16(map, d, to); 125 to += 2; 126 len -= 2; 127 } 128 } 129 130 static void dc21285_copy_to_8(struct map_info *map, unsigned long to, const void *from, ssize_t len) 131 { 132 map_word d; 133 d.x[0] = *((uint8_t*)from)++; 134 dc21285_write8(map, d, to); 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 #ifdef CONFIG_MTD_PARTITIONS 149 static struct mtd_partition *dc21285_parts; 150 static const char *probes[] = { "RedBoot", "cmdlinepart", NULL }; 151 #endif 152 153 static int __init init_dc21285(void) 154 { 155 156 #ifdef CONFIG_MTD_PARTITIONS 157 int nrparts; 158 #endif 159 160 /* Determine bankwidth */ 161 switch (*CSR_SA110_CNTL & (3<<14)) { 162 case SA110_CNTL_ROMWIDTH_8: 163 dc21285_map.bankwidth = 1; 164 dc21285_map.read = dc21285_read8; 165 dc21285_map.write = dc21285_write8; 166 dc21285_map.copy_to = dc21285_copy_to_8; 167 break; 168 case SA110_CNTL_ROMWIDTH_16: 169 dc21285_map.bankwidth = 2; 170 dc21285_map.read = dc21285_read16; 171 dc21285_map.write = dc21285_write16; 172 dc21285_map.copy_to = dc21285_copy_to_16; 173 break; 174 case SA110_CNTL_ROMWIDTH_32: 175 dc21285_map.bankwidth = 4; 176 dc21285_map.read = dc21285_read32; 177 dc21285_map.write = dc21285_write32; 178 dc21285_map.copy_to = dc21285_copy_to_32; 179 break; 180 default: 181 printk (KERN_ERR "DC21285 flash: undefined bankwidth\n"); 182 return -ENXIO; 183 } 184 printk (KERN_NOTICE "DC21285 flash support (%d-bit bankwidth)\n", 185 dc21285_map.bankwidth*8); 186 187 /* Let's map the flash area */ 188 dc21285_map.virt = ioremap(DC21285_FLASH, 16*1024*1024); 189 if (!dc21285_map.virt) { 190 printk("Failed to ioremap\n"); 191 return -EIO; 192 } 193 194 if (machine_is_ebsa285()) { 195 dc21285_mtd = do_map_probe("cfi_probe", &dc21285_map); 196 } else { 197 dc21285_mtd = do_map_probe("jedec_probe", &dc21285_map); 198 } 199 200 if (!dc21285_mtd) { 201 iounmap(dc21285_map.virt); 202 return -ENXIO; 203 } 204 205 dc21285_mtd->owner = THIS_MODULE; 206 207 #ifdef CONFIG_MTD_PARTITIONS 208 nrparts = parse_mtd_partitions(dc21285_mtd, probes, &dc21285_parts, 0); 209 if (nrparts > 0) 210 add_mtd_partitions(dc21285_mtd, dc21285_parts, nrparts); 211 else 212 #endif 213 add_mtd_device(dc21285_mtd); 214 215 if(machine_is_ebsa285()) { 216 /* 217 * Flash timing is determined with bits 19-16 of the 218 * CSR_SA110_CNTL. The value is the number of wait cycles, or 219 * 0 for 16 cycles (the default). Cycles are 20 ns. 220 * Here we use 7 for 140 ns flash chips. 221 */ 222 /* access time */ 223 *CSR_SA110_CNTL = ((*CSR_SA110_CNTL & ~0x000f0000) | (7 << 16)); 224 /* burst time */ 225 *CSR_SA110_CNTL = ((*CSR_SA110_CNTL & ~0x00f00000) | (7 << 20)); 226 /* tristate time */ 227 *CSR_SA110_CNTL = ((*CSR_SA110_CNTL & ~0x0f000000) | (7 << 24)); 228 } 229 230 return 0; 231 } 232 233 static void __exit cleanup_dc21285(void) 234 { 235 #ifdef CONFIG_MTD_PARTITIONS 236 if (dc21285_parts) { 237 del_mtd_partitions(dc21285_mtd); 238 kfree(dc21285_parts); 239 } else 240 #endif 241 del_mtd_device(dc21285_mtd); 242 243 map_destroy(dc21285_mtd); 244 iounmap(dc21285_map.virt); 245 } 246 247 module_init(init_dc21285); 248 module_exit(cleanup_dc21285); 249 250 251 MODULE_LICENSE("GPL"); 252 MODULE_AUTHOR("Nicolas Pitre <nico@cam.org>"); 253 MODULE_DESCRIPTION("MTD map driver for DC21285 boards"); 254