2 * Copyright (c) ???? Jochen Schäuble <psionic@psionic.de>
3 * Copyright (c) 2003-2004 Joern Engel <joern@wh.fh-wedel.de>
7 * one commend line parameter per device, each in the form:
8 * phram=<name>,<start>,<len>
9 * <name> may be up to 63 characters.
10 * <start> and <len> can be octal, decimal or hexadecimal. If followed
11 * by "ki", "Mi" or "Gi", the numbers will be interpreted as kilo, mega or
15 * phram=swap,64Mi,128Mi phram=test,900Mi,1Mi
18 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21 #include <linux/init.h>
22 #include <linux/kernel.h>
23 #include <linux/list.h>
24 #include <linux/module.h>
25 #include <linux/moduleparam.h>
26 #include <linux/slab.h>
27 #include <linux/mtd/mtd.h>
29 struct phram_mtd_list
{
31 struct list_head list
;
34 static LIST_HEAD(phram_list
);
37 static int phram_erase(struct mtd_info
*mtd
, struct erase_info
*instr
)
39 u_char
*start
= mtd
->priv
;
41 if (instr
->addr
+ instr
->len
> mtd
->size
)
44 memset(start
+ instr
->addr
, 0xff, instr
->len
);
46 /* This'll catch a few races. Free the thing before returning :)
47 * I don't feel at all ashamed. This kind of thing is possible anyway
48 * with flash, but unlikely.
51 instr
->state
= MTD_ERASE_DONE
;
53 mtd_erase_callback(instr
);
58 static int phram_point(struct mtd_info
*mtd
, loff_t from
, size_t len
,
59 size_t *retlen
, void **virt
, resource_size_t
*phys
)
61 if (from
+ len
> mtd
->size
)
64 /* can we return a physical address with this driver? */
68 *virt
= mtd
->priv
+ from
;
73 static void phram_unpoint(struct mtd_info
*mtd
, loff_t from
, size_t len
)
77 static int phram_read(struct mtd_info
*mtd
, loff_t from
, size_t len
,
78 size_t *retlen
, u_char
*buf
)
80 u_char
*start
= mtd
->priv
;
82 if (from
>= mtd
->size
)
85 if (len
> mtd
->size
- from
)
86 len
= mtd
->size
- from
;
88 memcpy(buf
, start
+ from
, len
);
94 static int phram_write(struct mtd_info
*mtd
, loff_t to
, size_t len
,
95 size_t *retlen
, const u_char
*buf
)
97 u_char
*start
= mtd
->priv
;
102 if (len
> mtd
->size
- to
)
103 len
= mtd
->size
- to
;
105 memcpy(start
+ to
, buf
, len
);
113 static void unregister_devices(void)
115 struct phram_mtd_list
*this, *safe
;
117 list_for_each_entry_safe(this, safe
, &phram_list
, list
) {
118 mtd_device_unregister(&this->mtd
);
119 iounmap(this->mtd
.priv
);
120 kfree(this->mtd
.name
);
125 static int register_device(char *name
, unsigned long start
, unsigned long len
)
127 struct phram_mtd_list
*new;
130 new = kzalloc(sizeof(*new), GFP_KERNEL
);
135 new->mtd
.priv
= ioremap(start
, len
);
136 if (!new->mtd
.priv
) {
137 pr_err("ioremap failed\n");
142 new->mtd
.name
= name
;
144 new->mtd
.flags
= MTD_CAP_RAM
;
145 new->mtd
.erase
= phram_erase
;
146 new->mtd
.point
= phram_point
;
147 new->mtd
.unpoint
= phram_unpoint
;
148 new->mtd
.read
= phram_read
;
149 new->mtd
.write
= phram_write
;
150 new->mtd
.owner
= THIS_MODULE
;
151 new->mtd
.type
= MTD_RAM
;
152 new->mtd
.erasesize
= PAGE_SIZE
;
153 new->mtd
.writesize
= 1;
156 if (mtd_device_register(&new->mtd
, NULL
, 0)) {
157 pr_err("Failed to register new device\n");
161 list_add_tail(&new->list
, &phram_list
);
165 iounmap(new->mtd
.priv
);
172 static int ustrtoul(const char *cp
, char **endp
, unsigned int base
)
174 unsigned long result
= simple_strtoul(cp
, endp
, base
);
183 /* By dwmw2 editorial decree, "ki", "Mi" or "Gi" are to be used. */
184 if ((*endp
)[1] == 'i')
190 static int parse_num32(uint32_t *num32
, const char *token
)
195 n
= ustrtoul(token
, &endp
, 0);
203 static int parse_name(char **pname
, const char *token
)
208 len
= strlen(token
) + 1;
212 name
= kmalloc(len
, GFP_KERNEL
);
223 static inline void kill_final_newline(char *str
)
225 char *newline
= strrchr(str
, '\n');
226 if (newline
&& !newline
[1])
231 #define parse_err(fmt, args...) do { \
232 pr_err(fmt , ## args); \
236 static int phram_setup(const char *val
, struct kernel_param
*kp
)
238 char buf
[64+12+12], *str
= buf
;
245 if (strnlen(val
, sizeof(buf
)) >= sizeof(buf
))
246 parse_err("parameter too long\n");
249 kill_final_newline(str
);
252 token
[i
] = strsep(&str
, ",");
255 parse_err("too many arguments\n");
258 parse_err("not enough arguments\n");
260 ret
= parse_name(&name
, token
[0]);
264 ret
= parse_num32(&start
, token
[1]);
267 parse_err("illegal start address\n");
270 ret
= parse_num32(&len
, token
[2]);
273 parse_err("illegal device length\n");
276 ret
= register_device(name
, start
, len
);
278 pr_info("%s device: %#x at %#x\n", name
, len
, start
);
285 module_param_call(phram
, phram_setup
, NULL
, NULL
, 000);
286 MODULE_PARM_DESC(phram
, "Memory region to map. \"phram=<name>,<start>,<length>\"");
289 static int __init
init_phram(void)
294 static void __exit
cleanup_phram(void)
296 unregister_devices();
299 module_init(init_phram
);
300 module_exit(cleanup_phram
);
302 MODULE_LICENSE("GPL");
303 MODULE_AUTHOR("Joern Engel <joern@wh.fh-wedel.de>");
304 MODULE_DESCRIPTION("MTD driver for physical RAM");
This page took 0.036625 seconds and 5 git commands to generate.