tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1/*
2 * $Id: walnut.c,v 1.2 2004/12/10 12:07:42 holindho Exp $
3 *
4 * Mapping for Walnut flash
5 * (used ebony.c as a "framework")
6 *
7 * Heikki Lindholm <holindho@infradead.org>
8 *
9 *
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by the
12 * Free Software Foundation; either version 2 of the License, or (at your
13 * option) any later version.
14 */
15
16#include <linux/module.h>
17#include <linux/types.h>
18#include <linux/kernel.h>
19#include <linux/init.h>
20#include <linux/mtd/mtd.h>
21#include <linux/mtd/map.h>
22#include <linux/mtd/partitions.h>
23#include <linux/config.h>
24#include <linux/version.h>
25#include <asm/io.h>
26#include <asm/ibm4xx.h>
27#include <platforms/4xx/walnut.h>
28
29/* these should be in platforms/4xx/walnut.h ? */
30#define WALNUT_FLASH_ONBD_N(x) (x & 0x02)
31#define WALNUT_FLASH_SRAM_SEL(x) (x & 0x01)
32#define WALNUT_FLASH_LOW 0xFFF00000
33#define WALNUT_FLASH_HIGH 0xFFF80000
34#define WALNUT_FLASH_SIZE 0x80000
35
36static struct mtd_info *flash;
37
38static struct map_info walnut_map = {
39 .name = "Walnut flash",
40 .size = WALNUT_FLASH_SIZE,
41 .bankwidth = 1,
42};
43
44/* Actually, OpenBIOS is the last 128 KiB of the flash - better
45 * partitioning could be made */
46static struct mtd_partition walnut_partitions[] = {
47 {
48 .name = "OpenBIOS",
49 .offset = 0x0,
50 .size = WALNUT_FLASH_SIZE,
51 /*.mask_flags = MTD_WRITEABLE, */ /* force read-only */
52 }
53};
54
55int __init init_walnut(void)
56{
57 u8 fpga_brds1;
58 void *fpga_brds1_adr;
59 void *fpga_status_adr;
60 unsigned long flash_base;
61
62 /* this should already be mapped (platform/4xx/walnut.c) */
63 fpga_status_adr = ioremap(WALNUT_FPGA_BASE, 8);
64 if (!fpga_status_adr)
65 return -ENOMEM;
66
67 fpga_brds1_adr = fpga_status_adr+5;
68 fpga_brds1 = readb(fpga_brds1_adr);
69 /* iounmap(fpga_status_adr); */
70
71 if (WALNUT_FLASH_ONBD_N(fpga_brds1)) {
72 printk("The on-board flash is disabled (U79 sw 5)!");
73 return -EIO;
74 }
75 if (WALNUT_FLASH_SRAM_SEL(fpga_brds1))
76 flash_base = WALNUT_FLASH_LOW;
77 else
78 flash_base = WALNUT_FLASH_HIGH;
79
80 walnut_map.phys = flash_base;
81 walnut_map.virt =
82 (void __iomem *)ioremap(flash_base, walnut_map.size);
83
84 if (!walnut_map.virt) {
85 printk("Failed to ioremap flash.\n");
86 return -EIO;
87 }
88
89 simple_map_init(&walnut_map);
90
91 flash = do_map_probe("jedec_probe", &walnut_map);
92 if (flash) {
93 flash->owner = THIS_MODULE;
94 add_mtd_partitions(flash, walnut_partitions,
95 ARRAY_SIZE(walnut_partitions));
96 } else {
97 printk("map probe failed for flash\n");
98 return -ENXIO;
99 }
100
101 return 0;
102}
103
104static void __exit cleanup_walnut(void)
105{
106 if (flash) {
107 del_mtd_partitions(flash);
108 map_destroy(flash);
109 }
110
111 if (walnut_map.virt) {
112 iounmap((void *)walnut_map.virt);
113 walnut_map.virt = 0;
114 }
115}
116
117module_init(init_walnut);
118module_exit(cleanup_walnut);
119
120MODULE_LICENSE("GPL");
121MODULE_AUTHOR("Heikki Lindholm <holindho@infradead.org>");
122MODULE_DESCRIPTION("MTD map and partitions for IBM 405GP Walnut boards");