110 lines
2.5 KiB
C
110 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* tsunami_flash.c
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*
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* flash chip on alpha ds10...
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*/
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#include <asm/io.h>
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#include <asm/core_tsunami.h>
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#include <linux/init.h>
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#include <linux/mtd/map.h>
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#include <linux/mtd/mtd.h>
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#define FLASH_ENABLE_PORT 0x00C00001
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#define FLASH_ENABLE_BYTE 0x01
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#define FLASH_DISABLE_BYTE 0x00
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#define MAX_TIG_FLASH_SIZE (12*1024*1024)
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static inline map_word tsunami_flash_read8(struct map_info *map, unsigned long offset)
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{
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map_word val;
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val.x[0] = tsunami_tig_readb(offset);
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return val;
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}
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static void tsunami_flash_write8(struct map_info *map, map_word value, unsigned long offset)
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{
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tsunami_tig_writeb(value.x[0], offset);
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}
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static void tsunami_flash_copy_from(
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struct map_info *map, void *addr, unsigned long offset, ssize_t len)
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{
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unsigned char *dest;
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dest = addr;
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while(len && (offset < MAX_TIG_FLASH_SIZE)) {
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*dest = tsunami_tig_readb(offset);
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offset++;
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dest++;
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len--;
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}
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}
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static void tsunami_flash_copy_to(
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struct map_info *map, unsigned long offset,
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const void *addr, ssize_t len)
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{
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const unsigned char *src;
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src = addr;
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while(len && (offset < MAX_TIG_FLASH_SIZE)) {
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tsunami_tig_writeb(*src, offset);
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offset++;
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src++;
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len--;
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}
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}
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/*
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* Deliberately don't provide operations wider than 8 bits. I don't
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* have then and it scares me to think how you could mess up if
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* you tried to use them. Buswidth is correctly so I'm safe.
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*/
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static struct map_info tsunami_flash_map = {
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.name = "flash chip on the Tsunami TIG bus",
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.size = MAX_TIG_FLASH_SIZE,
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.phys = NO_XIP,
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.bankwidth = 1,
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.read = tsunami_flash_read8,
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.copy_from = tsunami_flash_copy_from,
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.write = tsunami_flash_write8,
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.copy_to = tsunami_flash_copy_to,
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};
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static struct mtd_info *tsunami_flash_mtd;
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static void __exit cleanup_tsunami_flash(void)
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{
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struct mtd_info *mtd;
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mtd = tsunami_flash_mtd;
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if (mtd) {
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mtd_device_unregister(mtd);
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map_destroy(mtd);
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}
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tsunami_flash_mtd = 0;
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}
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static const char * const rom_probe_types[] = {
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"cfi_probe", "jedec_probe", "map_rom", NULL };
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static int __init init_tsunami_flash(void)
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{
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const char * const *type;
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tsunami_tig_writeb(FLASH_ENABLE_BYTE, FLASH_ENABLE_PORT);
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tsunami_flash_mtd = 0;
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type = rom_probe_types;
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for(; !tsunami_flash_mtd && *type; type++) {
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tsunami_flash_mtd = do_map_probe(*type, &tsunami_flash_map);
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}
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if (tsunami_flash_mtd) {
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tsunami_flash_mtd->owner = THIS_MODULE;
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mtd_device_register(tsunami_flash_mtd, NULL, 0);
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return 0;
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}
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return -ENXIO;
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}
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module_init(init_tsunami_flash);
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module_exit(cleanup_tsunami_flash);
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