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32#include <linux/module.h>
33#include <linux/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 <linux/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 memremap(start, length,
167 MEMREMAP_WB | MEMREMAP_WT | MEMREMAP_WC))) {
168 E("slram: memremap failed\n");
169 return -EIO;
170 }
171 ((slram_priv_t *)(*curmtd)->mtdinfo->priv)->end =
172 ((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start + length;
173
174
175 (*curmtd)->mtdinfo->name = name;
176 (*curmtd)->mtdinfo->size = length;
177 (*curmtd)->mtdinfo->flags = MTD_CAP_RAM;
178 (*curmtd)->mtdinfo->_erase = slram_erase;
179 (*curmtd)->mtdinfo->_point = slram_point;
180 (*curmtd)->mtdinfo->_unpoint = slram_unpoint;
181 (*curmtd)->mtdinfo->_read = slram_read;
182 (*curmtd)->mtdinfo->_write = slram_write;
183 (*curmtd)->mtdinfo->owner = THIS_MODULE;
184 (*curmtd)->mtdinfo->type = MTD_RAM;
185 (*curmtd)->mtdinfo->erasesize = SLRAM_BLK_SZ;
186 (*curmtd)->mtdinfo->writesize = 1;
187
188 if (mtd_device_register((*curmtd)->mtdinfo, NULL, 0)) {
189 E("slram: Failed to register new device\n");
190 memunmap(((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start);
191 kfree((*curmtd)->mtdinfo->priv);
192 kfree((*curmtd)->mtdinfo);
193 return(-EAGAIN);
194 }
195 T("slram: Registered device %s from %luKiB to %luKiB\n", name,
196 (start / 1024), ((start + length) / 1024));
197 T("slram: Mapped from 0x%p to 0x%p\n",
198 ((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start,
199 ((slram_priv_t *)(*curmtd)->mtdinfo->priv)->end);
200 return(0);
201}
202
203static void unregister_devices(void)
204{
205 slram_mtd_list_t *nextitem;
206
207 while (slram_mtdlist) {
208 nextitem = slram_mtdlist->next;
209 mtd_device_unregister(slram_mtdlist->mtdinfo);
210 memunmap(((slram_priv_t *)slram_mtdlist->mtdinfo->priv)->start);
211 kfree(slram_mtdlist->mtdinfo->priv);
212 kfree(slram_mtdlist->mtdinfo);
213 kfree(slram_mtdlist);
214 slram_mtdlist = nextitem;
215 }
216}
217
218static unsigned long handle_unit(unsigned long value, char *unit)
219{
220 if ((*unit == 'M') || (*unit == 'm')) {
221 return(value * 1024 * 1024);
222 } else if ((*unit == 'K') || (*unit == 'k')) {
223 return(value * 1024);
224 }
225 return(value);
226}
227
228static int parse_cmdline(char *devname, char *szstart, char *szlength)
229{
230 char *buffer;
231 unsigned long devstart;
232 unsigned long devlength;
233
234 if ((!devname) || (!szstart) || (!szlength)) {
235 unregister_devices();
236 return(-EINVAL);
237 }
238
239 devstart = simple_strtoul(szstart, &buffer, 0);
240 devstart = handle_unit(devstart, buffer);
241
242 if (*(szlength) != '+') {
243 devlength = simple_strtoul(szlength, &buffer, 0);
244 devlength = handle_unit(devlength, buffer);
245 if (devlength < devstart)
246 goto err_out;
247
248 devlength -= devstart;
249 } else {
250 devlength = simple_strtoul(szlength + 1, &buffer, 0);
251 devlength = handle_unit(devlength, buffer);
252 }
253 T("slram: devname=%s, devstart=0x%lx, devlength=0x%lx\n",
254 devname, devstart, devlength);
255 if (devlength % SLRAM_BLK_SZ != 0)
256 goto err_out;
257
258 if ((devstart = register_device(devname, devstart, devlength))){
259 unregister_devices();
260 return((int)devstart);
261 }
262 return(0);
263
264err_out:
265 E("slram: Illegal length parameter.\n");
266 return(-EINVAL);
267}
268
269#ifndef MODULE
270
271static int __init mtd_slram_setup(char *str)
272{
273 map = str;
274 return(1);
275}
276
277__setup("slram=", mtd_slram_setup);
278
279#endif
280
281static int __init init_slram(void)
282{
283 char *devname;
284
285#ifndef MODULE
286 char *devstart;
287 char *devlength;
288
289 if (!map) {
290 E("slram: not enough parameters.\n");
291 return(-EINVAL);
292 }
293 while (map) {
294 devname = devstart = devlength = NULL;
295
296 if (!(devname = strsep(&map, ","))) {
297 E("slram: No devicename specified.\n");
298 break;
299 }
300 T("slram: devname = %s\n", devname);
301 if ((!map) || (!(devstart = strsep(&map, ",")))) {
302 E("slram: No devicestart specified.\n");
303 }
304 T("slram: devstart = %s\n", devstart);
305 if ((!map) || (!(devlength = strsep(&map, ",")))) {
306 E("slram: No devicelength / -end specified.\n");
307 }
308 T("slram: devlength = %s\n", devlength);
309 if (parse_cmdline(devname, devstart, devlength) != 0) {
310 return(-EINVAL);
311 }
312 }
313#else
314 int count;
315 int i;
316
317 for (count = 0; count < SLRAM_MAX_DEVICES_PARAMS && map[count];
318 count++) {
319 }
320
321 if ((count % 3 != 0) || (count == 0)) {
322 E("slram: not enough parameters.\n");
323 return(-EINVAL);
324 }
325 for (i = 0; i < (count / 3); i++) {
326 devname = map[i * 3];
327
328 if (parse_cmdline(devname, map[i * 3 + 1], map[i * 3 + 2])!=0) {
329 return(-EINVAL);
330 }
331
332 }
333#endif
334
335 return(0);
336}
337
338static void __exit cleanup_slram(void)
339{
340 unregister_devices();
341}
342
343module_init(init_slram);
344module_exit(cleanup_slram);
345
346MODULE_LICENSE("GPL");
347MODULE_AUTHOR("Jochen Schaeuble <psionic@psionic.de>");
348MODULE_DESCRIPTION("MTD driver for uncached system RAM");
349
