3 * $Id: phram.c,v 1.1 2003/08/21 17:52:30 joern Exp $
5 * Copyright (c) Jochen Schaeuble <psionic@psionic.de>
6 * 07/2003 rewritten by Joern Engel <joern@wh.fh-wedel.de>
8 * DISCLAIMER: This driver makes use of Rusty's excellent module code,
9 * so it will not work for 2.4 without changes and it wont work for 2.4
10 * as a module without major changes. Oh well!
14 * one commend line parameter per device, each in the form:
15 * phram=<name>,<start>,<len>
16 * <name> may be up to 63 characters.
17 * <start> and <len> can be octal, decimal or hexadecimal. If followed
18 * by "k", "M" or "G", the numbers will be interpreted as kilo, mega or
24 #include <linux/init.h>
25 #include <linux/kernel.h>
26 #include <linux/list.h>
27 #include <linux/module.h>
28 #include <linux/moduleparam.h>
29 #include <linux/mtd/mtd.h>
31 #define ERROR(fmt, args...) printk(KERN_ERR "phram: " fmt , ## args)
33 struct phram_mtd_list {
34 struct list_head list;
35 struct mtd_info *mtdinfo;
38 static LIST_HEAD(phram_list);
42 int phram_erase(struct mtd_info *mtd, struct erase_info *instr)
44 u_char *start = (u_char *)mtd->priv;
46 if (instr->addr + instr->len > mtd->size)
49 memset(start + instr->addr, 0xff, instr->len);
51 /* This'll catch a few races. Free the thing before returning :)
52 * I don't feel at all ashamed. This kind of thing is possible anyway
53 * with flash, but unlikely.
56 instr->state = MTD_ERASE_DONE;
59 (*(instr->callback))(instr);
66 int phram_point(struct mtd_info *mtd, loff_t from, size_t len,
67 size_t *retlen, u_char **mtdbuf)
69 u_char *start = (u_char *)mtd->priv;
71 if (from + len > mtd->size)
74 *mtdbuf = start + from;
79 void phram_unpoint(struct mtd_info *mtd, u_char *addr, loff_t from, size_t len)
83 int phram_read(struct mtd_info *mtd, loff_t from, size_t len,
84 size_t *retlen, u_char *buf)
86 u_char *start = (u_char *)mtd->priv;
88 if (from + len > mtd->size)
91 memcpy(buf, start + from, len);
97 int phram_write(struct mtd_info *mtd, loff_t to, size_t len,
98 size_t *retlen, const u_char *buf)
100 u_char *start = (u_char *)mtd->priv;
102 if (to + len > mtd->size)
105 memcpy(start + to, buf, len);
113 static void unregister_devices(void)
115 struct phram_mtd_list *this;
117 list_for_each_entry(this, &phram_list, list) {
118 del_mtd_device(this->mtdinfo);
119 iounmap(this->mtdinfo->priv);
120 kfree(this->mtdinfo);
125 static int register_device(char *name, unsigned long start, unsigned long len)
127 struct phram_mtd_list *new;
130 new = kmalloc(sizeof(*new), GFP_KERNEL);
134 new->mtdinfo = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
138 memset(new->mtdinfo, 0, sizeof(struct mtd_info));
141 new->mtdinfo->priv = ioremap(start, len);
142 if (!new->mtdinfo->priv) {
143 ERROR("ioremap failed\n");
148 new->mtdinfo->name = name;
149 new->mtdinfo->size = len;
150 new->mtdinfo->flags = MTD_CAP_RAM | MTD_ERASEABLE | MTD_VOLATILE;
151 new->mtdinfo->erase = phram_erase;
152 new->mtdinfo->point = phram_point;
153 new->mtdinfo->unpoint = phram_unpoint;
154 new->mtdinfo->read = phram_read;
155 new->mtdinfo->write = phram_write;
156 new->mtdinfo->owner = THIS_MODULE;
157 new->mtdinfo->type = MTD_RAM;
158 new->mtdinfo->erasesize = 0x0;
161 if (add_mtd_device(new->mtdinfo)) {
162 ERROR("Failed to register new device\n");
166 list_add_tail(&new->list, &phram_list);
170 iounmap(new->mtdinfo->priv);
179 static int ustrtoul(const char *cp, char **endp, unsigned int base)
181 unsigned long result = simple_strtoul(cp, endp, base);
195 static int parse_num32(uint32_t *num32, const char *token)
200 n = ustrtoul(token, &endp, 0);
208 static int parse_name(char **pname, const char *token)
213 len = strlen(token) + 1;
217 name = kmalloc(len, GFP_KERNEL);
227 #define parse_err(fmt, args...) do { \
228 ERROR(fmt , ## args); \
232 static int phram_setup(const char *val, struct kernel_param *kp)
234 char buf[64+12+12], *str = buf;
241 if (strnlen(val, sizeof(str)) >= sizeof(str))
242 parse_err("parameter too long\n");
247 token[i] = strsep(&str, ",");
250 parse_err("too many arguments\n");
253 parse_err("not enough arguments\n");
255 ret = parse_name(&name, token[0]);
257 parse_err("out of memory\n");
259 parse_err("name too long\n");
263 ret = parse_num32(&start, token[1]);
265 parse_err("illegal start address\n");
267 ret = parse_num32(&len, token[2]);
269 parse_err("illegal device length\n");
271 register_device(name, start, len);
276 module_param_call(phram, phram_setup, NULL, NULL, 000);
277 MODULE_PARM_DESC(phram, "Memory region to map. \"map=<name>,<start><length>\"");
280 * Just for compatibility with slram, this is horrible and should go someday.
282 static int __init slram_setup(const char *val, struct kernel_param *kp)
284 char buf[256], *str = buf;
287 parse_err("no arguments to \"slram=\"\n");
289 if (strnlen(val, sizeof(str)) >= sizeof(str))
290 parse_err("parameter too long\n");
301 for (i=0; i<3; i++) {
302 token[i] = strsep(&str, ",");
305 parse_err("wrong number of arguments to \"slram=\"\n");
309 ret = parse_name(&name, token[0]);
311 parse_err("of memory\n");
313 parse_err("too long\n");
318 ret = parse_num32(&start, token[1]);
320 parse_err("illegal start address\n");
323 if (token[2][0] == '+')
324 ret = parse_num32(&len, token[2] + 1);
326 ret = parse_num32(&len, token[2]);
329 parse_err("illegal device length\n");
331 if (token[2][0] != '+') {
333 parse_err("end < start\n");
337 register_device(name, start, len);
342 module_param_call(slram, slram_setup, NULL, NULL, 000);
343 MODULE_PARM_DESC(slram, "List of memory regions to map. \"map=<name>,<start><length/end>\"");
346 int __init init_phram(void)
348 printk(KERN_ERR "phram loaded\n");
352 static void __exit cleanup_phram(void)
354 unregister_devices();
357 module_init(init_phram);
358 module_exit(cleanup_phram);
360 MODULE_LICENSE("GPL");
361 MODULE_AUTHOR("Jörn Engel <joern@wh.fh-wedel.de>");
362 MODULE_DESCRIPTION("MTD driver for physical RAM");