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)
tsunami_flash_read8(struct map_info * map,unsigned long offset)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
tsunami_flash_write8(struct map_info * map,map_word value,unsigned long offset)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
tsunami_flash_copy_from(struct map_info * map,void * addr,unsigned long offset,ssize_t len)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
tsunami_flash_copy_to(struct map_info * map,unsigned long offset,const void * addr,ssize_t len)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
cleanup_tsunami_flash(void)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
init_tsunami_flash(void)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