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32#include <linux/module.h>
33#include <asm/uaccess.h>
34#include <linux/types.h>
35#include <linux/kernel.h>
36#include <linux/ptrace.h>
37#include <linux/slab.h>
38#include <linux/string.h>
39#include <linux/timer.h>
40#include <linux/major.h>
41#include <linux/fs.h>
42#include <linux/ioctl.h>
43#include <linux/init.h>
44#include <asm/io.h>
45
46#include <linux/mtd/mtd.h>
47
48#define SLRAM_MAX_DEVICES_PARAMS 6
49#define SLRAM_BLK_SZ 0x4000
50
51#define T(fmt, args...) printk(KERN_DEBUG fmt, ## args)
52#define E(fmt, args...) printk(KERN_NOTICE fmt, ## args)
53
54typedef struct slram_priv {
55 u_char *start;
56 u_char *end;
57} slram_priv_t;
58
59typedef struct slram_mtd_list {
60 struct mtd_info *mtdinfo;
61 struct slram_mtd_list *next;
62} slram_mtd_list_t;
63
64#ifdef MODULE
65static char *map[SLRAM_MAX_DEVICES_PARAMS];
66
67module_param_array(map, charp, NULL, 0);
68MODULE_PARM_DESC(map, "List of memory regions to map. \"map=<name>, <start>, <length / end>\"");
69#else
70static char *map;
71#endif
72
73static slram_mtd_list_t *slram_mtdlist = NULL;
74
75static int slram_erase(struct mtd_info *, struct erase_info *);
76static int slram_point(struct mtd_info *, loff_t, size_t, size_t *, void **,
77 resource_size_t *);
78static int slram_unpoint(struct mtd_info *, loff_t, size_t);
79static int slram_read(struct mtd_info *, loff_t, size_t, size_t *, u_char *);
80static int slram_write(struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
81
82static int slram_erase(struct mtd_info *mtd, struct erase_info *instr)
83{
84 slram_priv_t *priv = mtd->priv;
85
86 memset(priv->start + instr->addr, 0xff, instr->len);
87
88
89
90
91 instr->state = MTD_ERASE_DONE;
92 mtd_erase_callback(instr);
93 return(0);
94}
95
96static int slram_point(struct mtd_info *mtd, loff_t from, size_t len,
97 size_t *retlen, void **virt, resource_size_t *phys)
98{
99 slram_priv_t *priv = mtd->priv;
100
101 *virt = priv->start + from;
102 *retlen = len;
103 return(0);
104}
105
106static int slram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
107{
108 return 0;
109}
110
111static int slram_read(struct mtd_info *mtd, loff_t from, size_t len,
112 size_t *retlen, u_char *buf)
113{
114 slram_priv_t *priv = mtd->priv;
115
116 memcpy(buf, priv->start + from, len);
117 *retlen = len;
118 return(0);
119}
120
121static int slram_write(struct mtd_info *mtd, loff_t to, size_t len,
122 size_t *retlen, const u_char *buf)
123{
124 slram_priv_t *priv = mtd->priv;
125
126 memcpy(priv->start + to, buf, len);
127 *retlen = len;
128 return(0);
129}
130
131
132
133static int register_device(char *name, unsigned long start, unsigned long length)
134{
135 slram_mtd_list_t **curmtd;
136
137 curmtd = &slram_mtdlist;
138 while (*curmtd) {
139 curmtd = &(*curmtd)->next;
140 }
141
142 *curmtd = kmalloc(sizeof(slram_mtd_list_t), GFP_KERNEL);
143 if (!(*curmtd)) {
144 E("slram: Cannot allocate new MTD device.\n");
145 return(-ENOMEM);
146 }
147 (*curmtd)->mtdinfo = kzalloc(sizeof(struct mtd_info), GFP_KERNEL);
148 (*curmtd)->next = NULL;
149
150 if ((*curmtd)->mtdinfo) {
151 (*curmtd)->mtdinfo->priv =
152 kzalloc(sizeof(slram_priv_t), GFP_KERNEL);
153
154 if (!(*curmtd)->mtdinfo->priv) {
155 kfree((*curmtd)->mtdinfo);
156 (*curmtd)->mtdinfo = NULL;
157 }
158 }
159
160 if (!(*curmtd)->mtdinfo) {
161 E("slram: Cannot allocate new MTD device.\n");
162 return(-ENOMEM);
163 }
164
165 if (!(((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start =
166 ioremap(start, length))) {
167 E("slram: ioremap failed\n");
168 return -EIO;
169 }
170 ((slram_priv_t *)(*curmtd)->mtdinfo->priv)->end =
171 ((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start + length;
172
173
174 (*curmtd)->mtdinfo->name = name;
175 (*curmtd)->mtdinfo->size = length;
176 (*curmtd)->mtdinfo->flags = MTD_CAP_RAM;
177 (*curmtd)->mtdinfo->_erase = slram_erase;
178 (*curmtd)->mtdinfo->_point = slram_point;
179 (*curmtd)->mtdinfo->_unpoint = slram_unpoint;
180 (*curmtd)->mtdinfo->_read = slram_read;
181 (*curmtd)->mtdinfo->_write = slram_write;
182 (*curmtd)->mtdinfo->owner = THIS_MODULE;
183 (*curmtd)->mtdinfo->type = MTD_RAM;
184 (*curmtd)->mtdinfo->erasesize = SLRAM_BLK_SZ;
185 (*curmtd)->mtdinfo->writesize = 1;
186
187 if (mtd_device_register((*curmtd)->mtdinfo, NULL, 0)) {
188 E("slram: Failed to register new device\n");
189 iounmap(((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start);
190 kfree((*curmtd)->mtdinfo->priv);
191 kfree((*curmtd)->mtdinfo);
192 return(-EAGAIN);
193 }
194 T("slram: Registered device %s from %luKiB to %luKiB\n", name,
195 (start / 1024), ((start + length) / 1024));
196 T("slram: Mapped from 0x%p to 0x%p\n",
197 ((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start,
198 ((slram_priv_t *)(*curmtd)->mtdinfo->priv)->end);
199 return(0);
200}
201
202static void unregister_devices(void)
203{
204 slram_mtd_list_t *nextitem;
205
206 while (slram_mtdlist) {
207 nextitem = slram_mtdlist->next;
208 mtd_device_unregister(slram_mtdlist->mtdinfo);
209 iounmap(((slram_priv_t *)slram_mtdlist->mtdinfo->priv)->start);
210 kfree(slram_mtdlist->mtdinfo->priv);
211 kfree(slram_mtdlist->mtdinfo);
212 kfree(slram_mtdlist);
213 slram_mtdlist = nextitem;
214 }
215}
216
217static unsigned long handle_unit(unsigned long value, char *unit)
218{
219 if ((*unit == 'M') || (*unit == 'm')) {
220 return(value * 1024 * 1024);
221 } else if ((*unit == 'K') || (*unit == 'k')) {
222 return(value * 1024);
223 }
224 return(value);
225}
226
227static int parse_cmdline(char *devname, char *szstart, char *szlength)
228{
229 char *buffer;
230 unsigned long devstart;
231 unsigned long devlength;
232
233 if ((!devname) || (!szstart) || (!szlength)) {
234 unregister_devices();
235 return(-EINVAL);
236 }
237
238 devstart = simple_strtoul(szstart, &buffer, 0);
239 devstart = handle_unit(devstart, buffer);
240
241 if (*(szlength) != '+') {
242 devlength = simple_strtoul(szlength, &buffer, 0);
243 devlength = handle_unit(devlength, buffer);
244 if (devlength < devstart)
245 goto err_out;
246
247 devlength -= devstart;
248 } else {
249 devlength = simple_strtoul(szlength + 1, &buffer, 0);
250 devlength = handle_unit(devlength, buffer);
251 }
252 T("slram: devname=%s, devstart=0x%lx, devlength=0x%lx\n",
253 devname, devstart, devlength);
254 if (devlength % SLRAM_BLK_SZ != 0)
255 goto err_out;
256
257 if ((devstart = register_device(devname, devstart, devlength))){
258 unregister_devices();
259 return((int)devstart);
260 }
261 return(0);
262
263err_out:
264 E("slram: Illegal length parameter.\n");
265 return(-EINVAL);
266}
267
268#ifndef MODULE
269
270static int __init mtd_slram_setup(char *str)
271{
272 map = str;
273 return(1);
274}
275
276__setup("slram=", mtd_slram_setup);
277
278#endif
279
280static int __init init_slram(void)
281{
282 char *devname;
283 int i;
284
285#ifndef MODULE
286 char *devstart;
287 char *devlength;
288
289 i = 0;
290
291 if (!map) {
292 E("slram: not enough parameters.\n");
293 return(-EINVAL);
294 }
295 while (map) {
296 devname = devstart = devlength = NULL;
297
298 if (!(devname = strsep(&map, ","))) {
299 E("slram: No devicename specified.\n");
300 break;
301 }
302 T("slram: devname = %s\n", devname);
303 if ((!map) || (!(devstart = strsep(&map, ",")))) {
304 E("slram: No devicestart specified.\n");
305 }
306 T("slram: devstart = %s\n", devstart);
307 if ((!map) || (!(devlength = strsep(&map, ",")))) {
308 E("slram: No devicelength / -end specified.\n");
309 }
310 T("slram: devlength = %s\n", devlength);
311 if (parse_cmdline(devname, devstart, devlength) != 0) {
312 return(-EINVAL);
313 }
314 }
315#else
316 int count;
317
318 for (count = 0; count < SLRAM_MAX_DEVICES_PARAMS && map[count];
319 count++) {
320 }
321
322 if ((count % 3 != 0) || (count == 0)) {
323 E("slram: not enough parameters.\n");
324 return(-EINVAL);
325 }
326 for (i = 0; i < (count / 3); i++) {
327 devname = map[i * 3];
328
329 if (parse_cmdline(devname, map[i * 3 + 1], map[i * 3 + 2])!=0) {
330 return(-EINVAL);
331 }
332
333 }
334#endif
335
336 return(0);
337}
338
339static void __exit cleanup_slram(void)
340{
341 unregister_devices();
342}
343
344module_init(init_slram);
345module_exit(cleanup_slram);
346
347MODULE_LICENSE("GPL");
348MODULE_AUTHOR("Jochen Schaeuble <psionic@psionic.de>");
349MODULE_DESCRIPTION("MTD driver for uncached system RAM");
350
