File: /usr/src/linux/drivers/mtd/devices/slram.c
1 /*======================================================================
2
3 $Id: slram.c,v 1.19 2001/06/02 20:33:20 dwmw2 Exp $
4
5 ======================================================================*/
6
7
8 #include <linux/module.h>
9 #include <asm/uaccess.h>
10 #include <linux/types.h>
11 #include <linux/kernel.h>
12 #include <linux/sched.h>
13 #include <linux/ptrace.h>
14 #include <linux/slab.h>
15 #include <linux/string.h>
16 #include <linux/timer.h>
17 #include <linux/major.h>
18 #include <linux/fs.h>
19 #include <linux/ioctl.h>
20 #include <linux/init.h>
21 #include <asm/io.h>
22 #include <asm/system.h>
23 #include <asm/segment.h>
24 #include <stdarg.h>
25
26 #include <linux/mtd/mtd.h>
27
28 #define SLRAM_MAX_DEVICES_PARAMS 6 /* 3 parameters / device */
29
30 #define T(fmt, args...) printk(KERN_DEBUG fmt, ## args)
31 #define E(fmt, args...) printk(KERN_NOTICE fmt, ## args)
32
33 typedef struct slram_priv {
34 u_char *start;
35 u_char *end;
36 } slram_priv_t;
37
38 typedef struct slram_mtd_list {
39 struct mtd_info *mtdinfo;
40 struct slram_mtd_list *next;
41 } slram_mtd_list_t;
42
43 #ifdef MODULE
44 static char *map[SLRAM_MAX_DEVICES_PARAMS];
45 #else
46 static char *map;
47 #endif
48
49 #ifdef MODULE
50 #if LINUX_VERSION_CODE < 0x20212
51 #define init_slram init_module
52 #define cleanup_slram cleanup_module
53 #endif
54
55 MODULE_PARM(map, "3-" __MODULE_STRING(SLRAM_MAX_DEVICES_PARAMS) "s");
56 MODULE_PARM_DESC(map, "List of memory regions to map. \"map=<name>, <start>, <length / end>\"");
57 #endif
58
59 static slram_mtd_list_t *slram_mtdlist = NULL;
60
61 int slram_erase(struct mtd_info *, struct erase_info *);
62 int slram_point(struct mtd_info *, loff_t, size_t, size_t *, u_char **);
63 void slram_unpoint(struct mtd_info *, u_char *);
64 int slram_read(struct mtd_info *, loff_t, size_t, size_t *, u_char *);
65 int slram_write(struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
66
67 int slram_erase(struct mtd_info *mtd, struct erase_info *instr)
68 {
69 slram_priv_t *priv = mtd->priv;
70
71 if (instr->addr + instr->len > mtd->size) {
72 return(-EINVAL);
73 }
74
75 memset(priv->start + instr->addr, 0xff, instr->len);
76
77 /* This'll catch a few races. Free the thing before returning :)
78 * I don't feel at all ashamed. This kind of thing is possible anyway
79 * with flash, but unlikely.
80 */
81
82 instr->state = MTD_ERASE_DONE;
83
84 if (instr->callback) {
85 (*(instr->callback))(instr);
86 }
87 else {
88 kfree(instr);
89 }
90
91 return(0);
92 }
93
94 int slram_point(struct mtd_info *mtd, loff_t from, size_t len,
95 size_t *retlen, u_char **mtdbuf)
96 {
97 slram_priv_t *priv = (slram_priv_t *)mtd->priv;
98
99 *mtdbuf = priv->start + from;
100 *retlen = len;
101 return(0);
102 }
103
104 void slram_unpoint(struct mtd_info *mtd, u_char *addr)
105 {
106 }
107
108 int slram_read(struct mtd_info *mtd, loff_t from, size_t len,
109 size_t *retlen, u_char *buf)
110 {
111 slram_priv_t *priv = (slram_priv_t *)mtd->priv;
112
113 memcpy(buf, priv->start + from, len);
114
115 *retlen = len;
116 return(0);
117 }
118
119 int slram_write(struct mtd_info *mtd, loff_t to, size_t len,
120 size_t *retlen, const u_char *buf)
121 {
122 slram_priv_t *priv = (slram_priv_t *)mtd->priv;
123
124 memcpy(priv->start + to, buf, len);
125
126 *retlen = len;
127 return(0);
128 }
129
130 /*====================================================================*/
131
132 int register_device(char *name, long start, long length)
133 {
134 slram_mtd_list_t **curmtd;
135
136 curmtd = &slram_mtdlist;
137 while (*curmtd) {
138 curmtd = &(*curmtd)->next;
139 }
140
141 *curmtd = kmalloc(sizeof(slram_mtd_list_t), GFP_KERNEL);
142 if (!curmtd) {
143 E("slram: Cannot allocate new MTD device.\n");
144 return(-ENOMEM);
145 }
146 (*curmtd)->mtdinfo = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
147 (*curmtd)->next = NULL;
148
149 if ((*curmtd)->mtdinfo) {
150 memset((char *)(*curmtd)->mtdinfo, 0, sizeof(struct mtd_info));
151 (*curmtd)->mtdinfo->priv =
152 (void *)kmalloc(sizeof(slram_priv_t), GFP_KERNEL);
153
154 if (!(*curmtd)->mtdinfo->priv) {
155 kfree((*curmtd)->mtdinfo);
156 (*curmtd)->mtdinfo = NULL;
157 } else {
158 memset((*curmtd)->mtdinfo->priv,0,sizeof(slram_priv_t));
159 }
160 }
161
162 if (!(*curmtd)->mtdinfo) {
163 E("slram: Cannot allocate new MTD device.\n");
164 return(-ENOMEM);
165 }
166
167 if (!(((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start =
168 ioremap(start, length))) {
169 E("slram: ioremap failed\n");
170 return -EIO;
171 }
172 ((slram_priv_t *)(*curmtd)->mtdinfo->priv)->end =
173 ((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start + length;
174
175
176 (*curmtd)->mtdinfo->name = name;
177 (*curmtd)->mtdinfo->size = length;
178 (*curmtd)->mtdinfo->flags = MTD_CLEAR_BITS | MTD_SET_BITS |
179 MTD_WRITEB_WRITEABLE | MTD_VOLATILE;
180 (*curmtd)->mtdinfo->erase = slram_erase;
181 (*curmtd)->mtdinfo->point = slram_point;
182 (*curmtd)->mtdinfo->unpoint = slram_unpoint;
183 (*curmtd)->mtdinfo->read = slram_read;
184 (*curmtd)->mtdinfo->write = slram_write;
185 (*curmtd)->mtdinfo->module = THIS_MODULE;
186 (*curmtd)->mtdinfo->type = MTD_RAM;
187 (*curmtd)->mtdinfo->erasesize = 0x10000;
188
189 if (add_mtd_device((*curmtd)->mtdinfo)) {
190 E("slram: Failed to register new device\n");
191 iounmap(((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start);
192 kfree((*curmtd)->mtdinfo->priv);
193 kfree((*curmtd)->mtdinfo);
194 return(-EAGAIN);
195 }
196 T("slram: Registered device %s from %dKiB to %dKiB\n", name,
197 (int)(start / 1024), (int)((start + length) / 1024));
198 T("slram: Mapped from 0x%p to 0x%p\n",
199 ((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start,
200 ((slram_priv_t *)(*curmtd)->mtdinfo->priv)->end);
201 return(0);
202 }
203
204 void unregister_devices(void)
205 {
206 slram_mtd_list_t *nextitem;
207
208 while (slram_mtdlist) {
209 nextitem = slram_mtdlist->next;
210 del_mtd_device(slram_mtdlist->mtdinfo);
211 iounmap(((slram_priv_t *)slram_mtdlist->mtdinfo->priv)->start);
212 kfree(slram_mtdlist->mtdinfo->priv);
213 kfree(slram_mtdlist->mtdinfo);
214 kfree(slram_mtdlist);
215 slram_mtdlist = nextitem;
216 }
217 }
218
219 int handle_unit(long value, char *unit)
220 {
221 if ((*unit == 'M') || (*unit == 'm')) {
222 return(value * 1024 * 1024);
223 } else if ((*unit == 'K') || (*unit == 'k')) {
224 return(value * 1024);
225 }
226 return(value);
227 }
228
229 int parse_cmdline(char *devname, char *szstart, char *szlength)
230 {
231 char *buffer;
232 long devstart;
233 long devlength;
234
235 if ((!devname) || (!szstart) || (!szlength)) {
236 unregister_devices();
237 return(-EINVAL);
238 }
239
240 devstart = simple_strtoul(szstart, &buffer, 0);
241 devstart = handle_unit(devstart, buffer);
242
243 if (*(szlength) != '+') {
244 devlength = simple_strtoul(szlength, &buffer, 0);
245 devlength = handle_unit(devlength, buffer) - devstart;
246 } else {
247 devlength = simple_strtoul(szlength + 1, &buffer, 0);
248 devlength = handle_unit(devlength, buffer);
249 }
250 T("slram: devname=%s, devstart=%li, devlength=%li\n",
251 devname, devstart, devlength);
252 if ((devstart < 0) || (devlength < 0)) {
253 E("slram: Illegal start / length parameter.\n");
254 return(-EINVAL);
255 }
256
257 if ((devstart = register_device(devname, devstart, devlength))){
258 unregister_devices();
259 return((int)devstart);
260 }
261 return(0);
262 }
263
264 #ifndef MODULE
265
266 static int __init mtd_slram_setup(char *str)
267 {
268 map = str;
269 return(1);
270 }
271
272 __setup("slram=", mtd_slram_setup);
273
274 #endif
275
276 int init_slram(void)
277 {
278 char *devname;
279 int i;
280
281 #ifndef MODULE
282 char *devstart;
283 char *devlength;
284
285 i = 0;
286
287 if (!map) {
288 E("slram: not enough parameters.\n");
289 return(-EINVAL);
290 }
291 while (map) {
292 devname = devstart = devlength = NULL;
293
294 if (!(devname = strsep(&map, ","))) {
295 E("slram: No devicename specified.\n");
296 break;
297 }
298 T("slram: devname = %s\n", devname);
299 if ((!map) || (!(devstart = strsep(&map, ",")))) {
300 E("slram: No devicestart specified.\n");
301 }
302 T("slram: devstart = %s\n", devstart);
303 if ((!map) || (!(devlength = strsep(&map, ",")))) {
304 E("slram: No devicelength / -end specified.\n");
305 }
306 T("slram: devlength = %s\n", devlength);
307 if (parse_cmdline(devname, devstart, devlength) != 0) {
308 return(-EINVAL);
309 }
310 }
311 #else
312 int count;
313
314 for (count = 0; (map[count]) && (count < SLRAM_MAX_DEVICES_PARAMS);
315 count++) {
316 }
317
318 if ((count % 3 != 0) || (count == 0)) {
319 E("slram: not enough parameters.\n");
320 return(-EINVAL);
321 }
322 for (i = 0; i < (count / 3); i++) {
323 devname = map[i * 3];
324
325 if (parse_cmdline(devname, map[i * 3 + 1], map[i * 3 + 2])!=0) {
326 return(-EINVAL);
327 }
328
329 }
330 #endif /* !MODULE */
331
332 return(0);
333 }
334
335 static void __exit cleanup_slram(void)
336 {
337 unregister_devices();
338 }
339
340 module_init(init_slram);
341 module_exit(cleanup_slram);
342