3 * $Id: phram.c,v 1.2 2004/08/09 13:19:44 dwmw2 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;
58 mtd_erase_callback(instr);
63 int phram_point(struct mtd_info *mtd, loff_t from, size_t len,
64 size_t *retlen, u_char **mtdbuf)
66 u_char *start = (u_char *)mtd->priv;
68 if (from + len > mtd->size)
71 *mtdbuf = start + from;
76 void phram_unpoint(struct mtd_info *mtd, u_char *addr, loff_t from, size_t len)
80 int phram_read(struct mtd_info *mtd, loff_t from, size_t len,
81 size_t *retlen, u_char *buf)
83 u_char *start = (u_char *)mtd->priv;
85 if (from + len > mtd->size)
88 memcpy(buf, start + from, len);
94 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 = (u_char *)mtd->priv;
99 if (to + len > mtd->size)
102 memcpy(start + to, buf, len);
110 static void unregister_devices(void)
112 struct phram_mtd_list *this;
114 list_for_each_entry(this, &phram_list, list) {
115 del_mtd_device(this->mtdinfo);
116 iounmap(this->mtdinfo->priv);
117 kfree(this->mtdinfo);
122 static int register_device(char *name, unsigned long start, unsigned long len)
124 struct phram_mtd_list *new;
127 new = kmalloc(sizeof(*new), GFP_KERNEL);
131 new->mtdinfo = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
135 memset(new->mtdinfo, 0, sizeof(struct mtd_info));
138 new->mtdinfo->priv = ioremap(start, len);
139 if (!new->mtdinfo->priv) {
140 ERROR("ioremap failed\n");
145 new->mtdinfo->name = name;
146 new->mtdinfo->size = len;
147 new->mtdinfo->flags = MTD_CAP_RAM | MTD_ERASEABLE | MTD_VOLATILE;
148 new->mtdinfo->erase = phram_erase;
149 new->mtdinfo->point = phram_point;
150 new->mtdinfo->unpoint = phram_unpoint;
151 new->mtdinfo->read = phram_read;
152 new->mtdinfo->write = phram_write;
153 new->mtdinfo->owner = THIS_MODULE;
154 new->mtdinfo->type = MTD_RAM;
155 new->mtdinfo->erasesize = 0x0;
158 if (add_mtd_device(new->mtdinfo)) {
159 ERROR("Failed to register new device\n");
163 list_add_tail(&new->list, &phram_list);
167 iounmap(new->mtdinfo->priv);
176 static int ustrtoul(const char *cp, char **endp, unsigned int base)
178 unsigned long result = simple_strtoul(cp, endp, base);
192 static int parse_num32(uint32_t *num32, const char *token)
197 n = ustrtoul(token, &endp, 0);
205 static int parse_name(char **pname, const char *token)
210 len = strlen(token) + 1;
214 name = kmalloc(len, GFP_KERNEL);
224 #define parse_err(fmt, args...) do { \
225 ERROR(fmt , ## args); \
229 static int phram_setup(const char *val, struct kernel_param *kp)
231 char buf[64+12+12], *str = buf;
238 if (strnlen(val, sizeof(str)) >= sizeof(str))
239 parse_err("parameter too long\n");
244 token[i] = strsep(&str, ",");
247 parse_err("too many arguments\n");
250 parse_err("not enough arguments\n");
252 ret = parse_name(&name, token[0]);
254 parse_err("out of memory\n");
256 parse_err("name too long\n");
260 ret = parse_num32(&start, token[1]);
262 parse_err("illegal start address\n");
264 ret = parse_num32(&len, token[2]);
266 parse_err("illegal device length\n");
268 register_device(name, start, len);
273 module_param_call(phram, phram_setup, NULL, NULL, 000);
274 MODULE_PARM_DESC(phram, "Memory region to map. \"map=<name>,<start><length>\"");
277 * Just for compatibility with slram, this is horrible and should go someday.
279 static int __init slram_setup(const char *val, struct kernel_param *kp)
281 char buf[256], *str = buf;
284 parse_err("no arguments to \"slram=\"\n");
286 if (strnlen(val, sizeof(str)) >= sizeof(str))
287 parse_err("parameter too long\n");
298 for (i=0; i<3; i++) {
299 token[i] = strsep(&str, ",");
302 parse_err("wrong number of arguments to \"slram=\"\n");
306 ret = parse_name(&name, token[0]);
308 parse_err("of memory\n");
310 parse_err("too long\n");
315 ret = parse_num32(&start, token[1]);
317 parse_err("illegal start address\n");
320 if (token[2][0] == '+')
321 ret = parse_num32(&len, token[2] + 1);
323 ret = parse_num32(&len, token[2]);
326 parse_err("illegal device length\n");
328 if (token[2][0] != '+') {
330 parse_err("end < start\n");
334 register_device(name, start, len);
339 module_param_call(slram, slram_setup, NULL, NULL, 000);
340 MODULE_PARM_DESC(slram, "List of memory regions to map. \"map=<name>,<start><length/end>\"");
343 int __init init_phram(void)
345 printk(KERN_ERR "phram loaded\n");
349 static void __exit cleanup_phram(void)
351 unregister_devices();
354 module_init(init_phram);
355 module_exit(cleanup_phram);
357 MODULE_LICENSE("GPL");
358 MODULE_AUTHOR("Jörn Engel <joern@wh.fh-wedel.de>");
359 MODULE_DESCRIPTION("MTD driver for physical RAM");