1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * tsunami_flash.c 4 * 5 * flash chip on alpha ds10... 6 */ 7 #include <asm/io.h> 8 #include <asm/core_tsunami.h> 9 #include <linux/init.h> 10 #include <linux/mtd/map.h> 11 #include <linux/mtd/mtd.h> 12 13 #define FLASH_ENABLE_PORT 0x00C00001 14 #define FLASH_ENABLE_BYTE 0x01 15 #define FLASH_DISABLE_BYTE 0x00 16 17 #define MAX_TIG_FLASH_SIZE (12*1024*1024) 18 static inline map_word tsunami_flash_read8(struct map_info *map, unsigned long offset) 19 { 20 map_word val; 21 val.x[0] = tsunami_tig_readb(offset); 22 return val; 23 } 24 25 static void tsunami_flash_write8(struct map_info *map, map_word value, unsigned long offset) 26 { 27 tsunami_tig_writeb(value.x[0], offset); 28 } 29 30 static void tsunami_flash_copy_from( 31 struct map_info *map, void *addr, unsigned long offset, ssize_t len) 32 { 33 unsigned char *dest; 34 dest = addr; 35 while(len && (offset < MAX_TIG_FLASH_SIZE)) { 36 *dest = tsunami_tig_readb(offset); 37 offset++; 38 dest++; 39 len--; 40 } 41 } 42 43 static void tsunami_flash_copy_to( 44 struct map_info *map, unsigned long offset, 45 const void *addr, ssize_t len) 46 { 47 const unsigned char *src; 48 src = addr; 49 while(len && (offset < MAX_TIG_FLASH_SIZE)) { 50 tsunami_tig_writeb(*src, offset); 51 offset++; 52 src++; 53 len--; 54 } 55 } 56 57 /* 58 * Deliberately don't provide operations wider than 8 bits. I don't 59 * have then and it scares me to think how you could mess up if 60 * you tried to use them. Buswidth is correctly so I'm safe. 61 */ 62 static struct map_info tsunami_flash_map = { 63 .name = "flash chip on the Tsunami TIG bus", 64 .size = MAX_TIG_FLASH_SIZE, 65 .phys = NO_XIP, 66 .bankwidth = 1, 67 .read = tsunami_flash_read8, 68 .copy_from = tsunami_flash_copy_from, 69 .write = tsunami_flash_write8, 70 .copy_to = tsunami_flash_copy_to, 71 }; 72 73 static struct mtd_info *tsunami_flash_mtd; 74 75 static void __exit cleanup_tsunami_flash(void) 76 { 77 struct mtd_info *mtd; 78 mtd = tsunami_flash_mtd; 79 if (mtd) { 80 mtd_device_unregister(mtd); 81 map_destroy(mtd); 82 } 83 tsunami_flash_mtd = 0; 84 } 85 86 static const char * const rom_probe_types[] = { 87 "cfi_probe", "jedec_probe", "map_rom", NULL }; 88 89 static int __init init_tsunami_flash(void) 90 { 91 const char * const *type; 92 93 tsunami_tig_writeb(FLASH_ENABLE_BYTE, FLASH_ENABLE_PORT); 94 95 tsunami_flash_mtd = 0; 96 type = rom_probe_types; 97 for(; !tsunami_flash_mtd && *type; type++) { 98 tsunami_flash_mtd = do_map_probe(*type, &tsunami_flash_map); 99 } 100 if (tsunami_flash_mtd) { 101 tsunami_flash_mtd->owner = THIS_MODULE; 102 mtd_device_register(tsunami_flash_mtd, NULL, 0); 103 return 0; 104 } 105 return -ENXIO; 106 } 107 108 module_init(init_tsunami_flash); 109 module_exit(cleanup_tsunami_flash); 110