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)
18static 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
25static 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
30static 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
43static 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 */
62static 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
73static struct mtd_info *tsunami_flash_mtd;
74
75static 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
86static const char * const rom_probe_types[] = {
87	"cfi_probe", "jedec_probe", "map_rom", NULL };
88
89static 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
108module_init(init_tsunami_flash);
109module_exit(cleanup_tsunami_flash);
110