2 * NVRAM variable manipulation (Linux kernel half)
4 * Copyright 2006, Broadcom Corporation
7 * THIS SOFTWARE IS OFFERED "AS IS", AND BROADCOM GRANTS NO WARRANTIES OF ANY
8 * KIND, EXPRESS OR IMPLIED, BY STATUTE, COMMUNICATION OR OTHERWISE. BROADCOM
9 * SPECIFICALLY DISCLAIMS ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS
10 * FOR A SPECIFIC PURPOSE OR NONINFRINGEMENT CONCERNING THIS SOFTWARE.
12 * $Id: nvram_linux.c,v 1.19 2006/04/08 07:12:42 honor Exp $
15 #include <linux/config.h>
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/kernel.h>
19 #include <linux/string.h>
20 #include <linux/interrupt.h>
21 #include <linux/spinlock.h>
22 #include <linux/slab.h>
23 #include <linux/bootmem.h>
24 #include <linux/wrapper.h>
26 #include <linux/miscdevice.h>
27 #include <linux/mtd/mtd.h>
28 #include <asm/addrspace.h>
30 #include <asm/uaccess.h>
34 #include <bcmendian.h>
43 /* In BSS to minimize text size and page aligned so it can be mmap()-ed */
44 static char nvram_buf[NVRAM_SPACE] __attribute__((aligned(PAGE_SIZE)));
48 #define early_nvram_get(name) nvram_get(name)
52 /* Global SB handle */
53 extern void *bcm947xx_sbh;
54 extern spinlock_t bcm947xx_sbh_lock;
57 #define sbh bcm947xx_sbh
58 #define sbh_lock bcm947xx_sbh_lock
60 #define MB * 1024 * 1024
62 /* Probe for NVRAM header */
64 early_nvram_init(void)
66 struct nvram_header *header;
68 struct sflash *info = NULL;
70 uint32 base, off, lim;
73 if ((cc = sb_setcore(sbh, SB_CC, 0)) != NULL) {
74 base = KSEG1ADDR(SB_FLASH2);
75 switch (readl(&cc->capabilities) & CAP_FLASH_MASK) {
82 if ((info = sflash_init(cc)) == NULL)
92 /* extif assumed, Stop at 4 MB */
93 base = KSEG1ADDR(SB_FLASH1);
97 /* XXX: hack for supporting the CFE environment stuff on WGT634U */
98 src = (u32 *) KSEG1ADDR(base + 8 * 1024 * 1024 - 0x2000);
99 dst = (u32 *) nvram_buf;
100 if ((lim == 0x02000000) && ((*src & 0xff00ff) == 0x000001)) {
101 printk("early_nvram_init: WGT634U NVRAM found.\n");
103 for (i = 0; i < 0x1ff0; i++) {
104 if (*src == 0xFFFFFFFF)
113 /* Windowed flash access */
114 header = (struct nvram_header *) KSEG1ADDR(base + off - NVRAM_SPACE);
115 if (header->magic == NVRAM_MAGIC)
120 /* Try embedded NVRAM at 4 KB and 1 KB as last resorts */
121 header = (struct nvram_header *) KSEG1ADDR(base + 4 KB);
122 if (header->magic == NVRAM_MAGIC)
125 header = (struct nvram_header *) KSEG1ADDR(base + 1 KB);
126 if (header->magic == NVRAM_MAGIC)
129 printk("early_nvram_init: NVRAM not found\n");
133 src = (u32 *) header;
134 dst = (u32 *) nvram_buf;
135 for (i = 0; i < sizeof(struct nvram_header); i += 4)
137 for (; i < header->len && i < NVRAM_SPACE; i += 4)
138 *dst++ = ltoh32(*src++);
141 /* Early (before mm or mtd) read-only access to NVRAM */
143 early_nvram_get(const char *name)
145 char *var, *value, *end, *eq;
157 /* Look for name=value and return value */
158 var = &nvram_buf[sizeof(struct nvram_header)];
159 end = nvram_buf + sizeof(nvram_buf) - 2;
160 end[0] = end[1] = '\0';
161 for (; *var; var = value + strlen(value) + 1) {
162 if (!(eq = strchr(var, '=')))
165 if ((eq - var) == strlen(name) && strncmp(var, name, (eq - var)) == 0)
173 early_nvram_getall(char *buf, int count)
187 /* Write name=value\0 ... \0\0 */
188 var = &nvram_buf[sizeof(struct nvram_header)];
189 end = nvram_buf + sizeof(nvram_buf) - 2;
190 end[0] = end[1] = '\0';
191 for (; *var; var += strlen(var) + 1) {
192 if ((count - len) <= (strlen(var) + 1))
194 len += sprintf(buf + len, "%s", var) + 1;
201 extern char * _nvram_get(const char *name);
202 extern int _nvram_set(const char *name, const char *value);
203 extern int _nvram_unset(const char *name);
204 extern int _nvram_getall(char *buf, int count);
205 extern int _nvram_commit(struct nvram_header *header);
206 extern int _nvram_init(void *sbh);
207 extern void _nvram_exit(void);
210 static spinlock_t nvram_lock = SPIN_LOCK_UNLOCKED;
211 static struct semaphore nvram_sem;
212 static unsigned long nvram_offset = 0;
213 static int nvram_major = -1;
214 static devfs_handle_t nvram_handle = NULL;
215 static struct mtd_info *nvram_mtd = NULL;
218 _nvram_read(char *buf)
220 struct nvram_header *header = (struct nvram_header *) buf;
224 MTD_READ(nvram_mtd, nvram_mtd->size - NVRAM_SPACE, NVRAM_SPACE, &len, buf) ||
225 len != NVRAM_SPACE ||
226 header->magic != NVRAM_MAGIC) {
227 /* Maybe we can recover some data from early initialization */
228 memcpy(buf, nvram_buf, NVRAM_SPACE);
235 _nvram_realloc(struct nvram_tuple *t, const char *name, const char *value)
237 if ((nvram_offset + strlen(value) + 1) > NVRAM_SPACE)
241 if (!(t = kmalloc(sizeof(struct nvram_tuple) + strlen(name) + 1, GFP_ATOMIC)))
245 t->name = (char *) &t[1];
246 strcpy(t->name, name);
252 if (!t->value || strcmp(t->value, value)) {
253 t->value = &nvram_buf[nvram_offset];
254 strcpy(t->value, value);
255 nvram_offset += strlen(value) + 1;
262 _nvram_free(struct nvram_tuple *t)
271 nvram_set(const char *name, const char *value)
275 struct nvram_header *header;
277 spin_lock_irqsave(&nvram_lock, flags);
278 if ((ret = _nvram_set(name, value))) {
279 /* Consolidate space and try again */
280 if ((header = kmalloc(NVRAM_SPACE, GFP_ATOMIC))) {
281 if (_nvram_commit(header) == 0)
282 ret = _nvram_set(name, value);
286 spin_unlock_irqrestore(&nvram_lock, flags);
292 real_nvram_get(const char *name)
297 spin_lock_irqsave(&nvram_lock, flags);
298 value = _nvram_get(name);
299 spin_unlock_irqrestore(&nvram_lock, flags);
305 nvram_get(const char *name)
307 if (nvram_major >= 0)
308 return real_nvram_get(name);
310 return early_nvram_get(name);
314 nvram_unset(const char *name)
319 spin_lock_irqsave(&nvram_lock, flags);
320 ret = _nvram_unset(name);
321 spin_unlock_irqrestore(&nvram_lock, flags);
327 erase_callback(struct erase_info *done)
329 wait_queue_head_t *wait_q = (wait_queue_head_t *) done->priv;
337 size_t erasesize, len, magic_len;
340 struct nvram_header *header;
343 DECLARE_WAITQUEUE(wait, current);
344 wait_queue_head_t wait_q;
345 struct erase_info erase;
346 u_int32_t magic_offset = 0; /* Offset for writing MAGIC # */
349 printk("nvram_commit: NVRAM not found\n");
353 if (in_interrupt()) {
354 printk("nvram_commit: not committing in interrupt\n");
358 /* Backup sector blocks to be erased */
359 erasesize = ROUNDUP(NVRAM_SPACE, nvram_mtd->erasesize);
360 if (!(buf = kmalloc(erasesize, GFP_KERNEL))) {
361 printk("nvram_commit: out of memory\n");
367 if ((i = erasesize - NVRAM_SPACE) > 0) {
368 offset = nvram_mtd->size - erasesize;
370 ret = MTD_READ(nvram_mtd, offset, i, &len, buf);
371 if (ret || len != i) {
372 printk("nvram_commit: read error ret = %d, len = %d/%d\n", ret, len, i);
376 header = (struct nvram_header *)(buf + i);
377 magic_offset = i + ((void *)&header->magic - (void *)header);
379 offset = nvram_mtd->size - NVRAM_SPACE;
380 magic_offset = ((void *)&header->magic - (void *)header);
381 header = (struct nvram_header *)buf;
384 /* clear the existing magic # to mark the NVRAM as unusable
385 we can pull MAGIC bits low without erase */
386 header->magic = NVRAM_CLEAR_MAGIC; /* All zeros magic */
388 /* Unlock sector blocks (for Intel 28F320C3B flash) , 20060309 */
389 if(nvram_mtd->unlock)
390 nvram_mtd->unlock(nvram_mtd, offset, nvram_mtd->erasesize);
392 ret = MTD_WRITE(nvram_mtd, offset + magic_offset, sizeof(header->magic),
393 &magic_len, (char *)&header->magic);
394 if (ret || magic_len != sizeof(header->magic)) {
395 printk("nvram_commit: clear MAGIC error\n");
400 header->magic = NVRAM_MAGIC; /* reset MAGIC before we regenerate the NVRAM,
401 otherwise we'll have an incorrect CRC */
402 /* Regenerate NVRAM */
403 spin_lock_irqsave(&nvram_lock, flags);
404 ret = _nvram_commit(header);
405 spin_unlock_irqrestore(&nvram_lock, flags);
409 /* Erase sector blocks */
410 init_waitqueue_head(&wait_q);
411 for (; offset < nvram_mtd->size - NVRAM_SPACE + header->len; offset += nvram_mtd->erasesize) {
412 erase.mtd = nvram_mtd;
414 erase.len = nvram_mtd->erasesize;
415 erase.callback = erase_callback;
416 erase.priv = (u_long) &wait_q;
418 set_current_state(TASK_INTERRUPTIBLE);
419 add_wait_queue(&wait_q, &wait);
421 /* Unlock sector blocks */
422 if (nvram_mtd->unlock)
423 nvram_mtd->unlock(nvram_mtd, offset, nvram_mtd->erasesize);
425 if ((ret = MTD_ERASE(nvram_mtd, &erase))) {
426 set_current_state(TASK_RUNNING);
427 remove_wait_queue(&wait_q, &wait);
428 printk("nvram_commit: erase error\n");
432 /* Wait for erase to finish */
434 remove_wait_queue(&wait_q, &wait);
437 /* Write partition up to end of data area */
438 header->magic = NVRAM_INVALID_MAGIC; /* All ones magic */
439 offset = nvram_mtd->size - erasesize;
440 i = erasesize - NVRAM_SPACE + header->len;
441 ret = MTD_WRITE(nvram_mtd, offset, i, &len, buf);
442 if (ret || len != i) {
443 printk("nvram_commit: write error\n");
448 /* Now mark the NVRAM in flash as "valid" by setting the correct
450 header->magic = NVRAM_MAGIC;
451 ret = MTD_WRITE(nvram_mtd, offset + magic_offset, sizeof(header->magic),
452 &magic_len, (char *)&header->magic);
453 if (ret || magic_len != sizeof(header->magic)) {
454 printk("nvram_commit: write MAGIC error\n");
460 * Reading a few bytes back here will put the device
461 * back to the correct mode on certain flashes */
462 offset = nvram_mtd->size - erasesize;
463 ret = MTD_READ(nvram_mtd, offset, 4, &len, buf);
473 nvram_getall(char *buf, int count)
478 spin_lock_irqsave(&nvram_lock, flags);
479 if (nvram_major >= 0)
480 ret = _nvram_getall(buf, count);
482 ret = early_nvram_getall(buf, count);
483 spin_unlock_irqrestore(&nvram_lock, flags);
494 /* User mode interface below */
497 dev_nvram_read(struct file *file, char *buf, size_t count, loff_t *ppos)
499 char tmp[100], *name = tmp, *value;
503 if (count > sizeof(tmp)) {
504 if (!(name = kmalloc(count, GFP_KERNEL)))
508 if (copy_from_user(name, buf, count)) {
514 /* Get all variables */
515 ret = nvram_getall(name, count);
517 if (copy_to_user(buf, name, count)) {
524 if (!(value = nvram_get(name))) {
529 /* Provide the offset into mmap() space */
530 off = (unsigned long) value - (unsigned long) nvram_buf;
532 if (put_user(off, (unsigned long *) buf)) {
537 ret = sizeof(unsigned long);
550 dev_nvram_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
552 char tmp[100], *name = tmp, *value;
555 if (count > sizeof(tmp)) {
556 if (!(name = kmalloc(count, GFP_KERNEL)))
560 if (copy_from_user(name, buf, count)) {
566 name = strsep(&value, "=");
568 ret = nvram_set(name, value) ? : count;
570 ret = nvram_unset(name) ? : count;
580 dev_nvram_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
582 if (cmd != NVRAM_MAGIC)
585 return nvram_commit();
589 dev_nvram_mmap(struct file *file, struct vm_area_struct *vma)
591 unsigned long offset = virt_to_phys(nvram_buf);
593 if (remap_page_range(vma->vm_start, offset, vma->vm_end-vma->vm_start,
601 dev_nvram_open(struct inode *inode, struct file * file)
608 dev_nvram_release(struct inode *inode, struct file * file)
614 static struct file_operations dev_nvram_fops = {
616 open: dev_nvram_open,
617 release: dev_nvram_release,
618 read: dev_nvram_read,
619 write: dev_nvram_write,
620 ioctl: dev_nvram_ioctl,
621 mmap: dev_nvram_mmap,
628 struct page *page, *end;
631 devfs_unregister(nvram_handle);
633 if (nvram_major >= 0)
634 devfs_unregister_chrdev(nvram_major, "nvram");
637 put_mtd_device(nvram_mtd);
639 while ((PAGE_SIZE << order) < NVRAM_SPACE)
641 end = virt_to_page(nvram_buf + (PAGE_SIZE << order) - 1);
642 for (page = virt_to_page(nvram_buf); page <= end; page++)
643 mem_map_unreserve(page);
651 int order = 0, ret = 0;
652 struct page *page, *end;
655 /* Allocate and reserve memory to mmap() */
656 while ((PAGE_SIZE << order) < NVRAM_SPACE)
658 end = virt_to_page(nvram_buf + (PAGE_SIZE << order) - 1);
659 for (page = virt_to_page(nvram_buf); page <= end; page++)
660 mem_map_reserve(page);
663 /* Find associated MTD device */
664 for (i = 0; i < MAX_MTD_DEVICES; i++) {
665 nvram_mtd = get_mtd_device(NULL, i);
667 if (!strcmp(nvram_mtd->name, "nvram") &&
668 nvram_mtd->size >= NVRAM_SPACE)
670 put_mtd_device(nvram_mtd);
673 if (i >= MAX_MTD_DEVICES)
677 /* Initialize hash table lock */
678 spin_lock_init(&nvram_lock);
680 /* Initialize commit semaphore */
681 init_MUTEX(&nvram_sem);
683 /* Register char device */
684 if ((nvram_major = devfs_register_chrdev(0, "nvram", &dev_nvram_fops)) < 0) {
689 /* Initialize hash table */
692 /* Create /dev/nvram handle */
693 nvram_handle = devfs_register(NULL, "nvram", DEVFS_FL_NONE, nvram_major, 0,
694 S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP, &dev_nvram_fops, NULL);
696 /* Set the SDRAM NCDL value into NVRAM if not already done */
697 if (getintvar(NULL, "sdram_ncdl") == 0) {
699 char buf[] = "0x00000000";
701 if ((ncdl = sb_memc_get_ncdl(sbh))) {
702 sprintf(buf, "0x%08x", ncdl);
703 nvram_set("sdram_ncdl", buf);
715 module_init(dev_nvram_init);
716 module_exit(dev_nvram_exit);