xref: /openbmc/linux/drivers/mtd/maps/tsunami_flash.c (revision 293d5b43)
1 /*
2  * tsunami_flash.c
3  *
4  * flash chip on alpha ds10...
5  */
6 #include <asm/io.h>
7 #include <asm/core_tsunami.h>
8 #include <linux/init.h>
9 #include <linux/mtd/map.h>
10 #include <linux/mtd/mtd.h>
11 
12 #define FLASH_ENABLE_PORT 0x00C00001
13 #define FLASH_ENABLE_BYTE 0x01
14 #define FLASH_DISABLE_BYTE 0x00
15 
16 #define MAX_TIG_FLASH_SIZE (12*1024*1024)
17 static inline map_word tsunami_flash_read8(struct map_info *map, unsigned long offset)
18 {
19 	map_word val;
20 	val.x[0] = tsunami_tig_readb(offset);
21 	return val;
22 }
23 
24 static void tsunami_flash_write8(struct map_info *map, map_word value, unsigned long offset)
25 {
26 	tsunami_tig_writeb(value.x[0], offset);
27 }
28 
29 static void tsunami_flash_copy_from(
30 	struct map_info *map, void *addr, unsigned long offset, ssize_t len)
31 {
32 	unsigned char *dest;
33 	dest = addr;
34 	while(len && (offset < MAX_TIG_FLASH_SIZE)) {
35 		*dest = tsunami_tig_readb(offset);
36 		offset++;
37 		dest++;
38 		len--;
39 	}
40 }
41 
42 static void tsunami_flash_copy_to(
43 	struct map_info *map, unsigned long offset,
44 	const void *addr, ssize_t len)
45 {
46 	const unsigned char *src;
47 	src = addr;
48 	while(len && (offset < MAX_TIG_FLASH_SIZE)) {
49 		tsunami_tig_writeb(*src, offset);
50 		offset++;
51 		src++;
52 		len--;
53 	}
54 }
55 
56 /*
57  * Deliberately don't provide operations wider than 8 bits.  I don't
58  * have then and it scares me to think how you could mess up if
59  * you tried to use them.   Buswidth is correctly so I'm safe.
60  */
61 static struct map_info tsunami_flash_map = {
62 	.name = "flash chip on the Tsunami TIG bus",
63 	.size = MAX_TIG_FLASH_SIZE,
64 	.phys = NO_XIP,
65 	.bankwidth = 1,
66 	.read = tsunami_flash_read8,
67 	.copy_from = tsunami_flash_copy_from,
68 	.write = tsunami_flash_write8,
69 	.copy_to = tsunami_flash_copy_to,
70 };
71 
72 static struct mtd_info *tsunami_flash_mtd;
73 
74 static void __exit  cleanup_tsunami_flash(void)
75 {
76 	struct mtd_info *mtd;
77 	mtd = tsunami_flash_mtd;
78 	if (mtd) {
79 		mtd_device_unregister(mtd);
80 		map_destroy(mtd);
81 	}
82 	tsunami_flash_mtd = 0;
83 }
84 
85 static const char * const rom_probe_types[] = {
86 	"cfi_probe", "jedec_probe", "map_rom", NULL };
87 
88 static int __init init_tsunami_flash(void)
89 {
90 	const char * const *type;
91 
92 	tsunami_tig_writeb(FLASH_ENABLE_BYTE, FLASH_ENABLE_PORT);
93 
94 	tsunami_flash_mtd = 0;
95 	type = rom_probe_types;
96 	for(; !tsunami_flash_mtd && *type; type++) {
97 		tsunami_flash_mtd = do_map_probe(*type, &tsunami_flash_map);
98 	}
99 	if (tsunami_flash_mtd) {
100 		tsunami_flash_mtd->owner = THIS_MODULE;
101 		mtd_device_register(tsunami_flash_mtd, NULL, 0);
102 		return 0;
103 	}
104 	return -ENXIO;
105 }
106 
107 module_init(init_tsunami_flash);
108 module_exit(cleanup_tsunami_flash);
109