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(master: 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(name: *type, map: &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 | |