usb: renesas_usbhs: fixup comment-out
[linux-2.6/next.git] / drivers / char / nvram.c
blob166f1e7aaa7ee844c4a36b8950cb9f343e0f5c82
1 /*
2 * CMOS/NV-RAM driver for Linux
4 * Copyright (C) 1997 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
5 * idea by and with help from Richard Jelinek <rj@suse.de>
6 * Portions copyright (c) 2001,2002 Sun Microsystems (thockin@sun.com)
8 * This driver allows you to access the contents of the non-volatile memory in
9 * the mc146818rtc.h real-time clock. This chip is built into all PCs and into
10 * many Atari machines. In the former it's called "CMOS-RAM", in the latter
11 * "NVRAM" (NV stands for non-volatile).
13 * The data are supplied as a (seekable) character device, /dev/nvram. The
14 * size of this file is dependent on the controller. The usual size is 114,
15 * the number of freely available bytes in the memory (i.e., not used by the
16 * RTC itself).
18 * Checksums over the NVRAM contents are managed by this driver. In case of a
19 * bad checksum, reads and writes return -EIO. The checksum can be initialized
20 * to a sane state either by ioctl(NVRAM_INIT) (clear whole NVRAM) or
21 * ioctl(NVRAM_SETCKS) (doesn't change contents, just makes checksum valid
22 * again; use with care!)
24 * This file also provides some functions for other parts of the kernel that
25 * want to access the NVRAM: nvram_{read,write,check_checksum,set_checksum}.
26 * Obviously this can be used only if this driver is always configured into
27 * the kernel and is not a module. Since the functions are used by some Atari
28 * drivers, this is the case on the Atari.
31 * 1.1 Cesar Barros: SMP locking fixes
32 * added changelog
33 * 1.2 Erik Gilling: Cobalt Networks support
34 * Tim Hockin: general cleanup, Cobalt support
35 * 1.3 Wim Van Sebroeck: convert PRINT_PROC to seq_file
38 #define NVRAM_VERSION "1.3"
40 #include <linux/module.h>
41 #include <linux/nvram.h>
43 #define PC 1
44 #define ATARI 2
46 /* select machine configuration */
47 #if defined(CONFIG_ATARI)
48 # define MACH ATARI
49 #elif defined(__i386__) || defined(__x86_64__) || defined(__arm__) /* and ?? */
50 # define MACH PC
51 #else
52 # error Cannot build nvram driver for this machine configuration.
53 #endif
55 #if MACH == PC
57 /* RTC in a PC */
58 #define CHECK_DRIVER_INIT() 1
60 /* On PCs, the checksum is built only over bytes 2..31 */
61 #define PC_CKS_RANGE_START 2
62 #define PC_CKS_RANGE_END 31
63 #define PC_CKS_LOC 32
64 #define NVRAM_BYTES (128-NVRAM_FIRST_BYTE)
66 #define mach_check_checksum pc_check_checksum
67 #define mach_set_checksum pc_set_checksum
68 #define mach_proc_infos pc_proc_infos
70 #endif
72 #if MACH == ATARI
74 /* Special parameters for RTC in Atari machines */
75 #include <asm/atarihw.h>
76 #include <asm/atariints.h>
77 #define RTC_PORT(x) (TT_RTC_BAS + 2*(x))
78 #define CHECK_DRIVER_INIT() (MACH_IS_ATARI && ATARIHW_PRESENT(TT_CLK))
80 #define NVRAM_BYTES 50
82 /* On Ataris, the checksum is over all bytes except the checksum bytes
83 * themselves; these are at the very end */
84 #define ATARI_CKS_RANGE_START 0
85 #define ATARI_CKS_RANGE_END 47
86 #define ATARI_CKS_LOC 48
88 #define mach_check_checksum atari_check_checksum
89 #define mach_set_checksum atari_set_checksum
90 #define mach_proc_infos atari_proc_infos
92 #endif
94 /* Note that *all* calls to CMOS_READ and CMOS_WRITE must be done with
95 * rtc_lock held. Due to the index-port/data-port design of the RTC, we
96 * don't want two different things trying to get to it at once. (e.g. the
97 * periodic 11 min sync from time.c vs. this driver.)
100 #include <linux/types.h>
101 #include <linux/errno.h>
102 #include <linux/miscdevice.h>
103 #include <linux/ioport.h>
104 #include <linux/fcntl.h>
105 #include <linux/mc146818rtc.h>
106 #include <linux/init.h>
107 #include <linux/proc_fs.h>
108 #include <linux/seq_file.h>
109 #include <linux/spinlock.h>
110 #include <linux/io.h>
111 #include <linux/uaccess.h>
112 #include <linux/mutex.h>
114 #include <asm/system.h>
116 static DEFINE_MUTEX(nvram_mutex);
117 static DEFINE_SPINLOCK(nvram_state_lock);
118 static int nvram_open_cnt; /* #times opened */
119 static int nvram_open_mode; /* special open modes */
120 #define NVRAM_WRITE 1 /* opened for writing (exclusive) */
121 #define NVRAM_EXCL 2 /* opened with O_EXCL */
123 static int mach_check_checksum(void);
124 static void mach_set_checksum(void);
126 #ifdef CONFIG_PROC_FS
127 static void mach_proc_infos(unsigned char *contents, struct seq_file *seq,
128 void *offset);
129 #endif
132 * These functions are provided to be called internally or by other parts of
133 * the kernel. It's up to the caller to ensure correct checksum before reading
134 * or after writing (needs to be done only once).
136 * It is worth noting that these functions all access bytes of general
137 * purpose memory in the NVRAM - that is to say, they all add the
138 * NVRAM_FIRST_BYTE offset. Pass them offsets into NVRAM as if you did not
139 * know about the RTC cruft.
142 unsigned char __nvram_read_byte(int i)
144 return CMOS_READ(NVRAM_FIRST_BYTE + i);
146 EXPORT_SYMBOL(__nvram_read_byte);
148 unsigned char nvram_read_byte(int i)
150 unsigned long flags;
151 unsigned char c;
153 spin_lock_irqsave(&rtc_lock, flags);
154 c = __nvram_read_byte(i);
155 spin_unlock_irqrestore(&rtc_lock, flags);
156 return c;
158 EXPORT_SYMBOL(nvram_read_byte);
160 /* This races nicely with trying to read with checksum checking (nvram_read) */
161 void __nvram_write_byte(unsigned char c, int i)
163 CMOS_WRITE(c, NVRAM_FIRST_BYTE + i);
165 EXPORT_SYMBOL(__nvram_write_byte);
167 void nvram_write_byte(unsigned char c, int i)
169 unsigned long flags;
171 spin_lock_irqsave(&rtc_lock, flags);
172 __nvram_write_byte(c, i);
173 spin_unlock_irqrestore(&rtc_lock, flags);
175 EXPORT_SYMBOL(nvram_write_byte);
177 int __nvram_check_checksum(void)
179 return mach_check_checksum();
181 EXPORT_SYMBOL(__nvram_check_checksum);
183 int nvram_check_checksum(void)
185 unsigned long flags;
186 int rv;
188 spin_lock_irqsave(&rtc_lock, flags);
189 rv = __nvram_check_checksum();
190 spin_unlock_irqrestore(&rtc_lock, flags);
191 return rv;
193 EXPORT_SYMBOL(nvram_check_checksum);
195 static void __nvram_set_checksum(void)
197 mach_set_checksum();
200 #if 0
201 void nvram_set_checksum(void)
203 unsigned long flags;
205 spin_lock_irqsave(&rtc_lock, flags);
206 __nvram_set_checksum();
207 spin_unlock_irqrestore(&rtc_lock, flags);
209 #endif /* 0 */
212 * The are the file operation function for user access to /dev/nvram
215 static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
217 switch (origin) {
218 case 0:
219 /* nothing to do */
220 break;
221 case 1:
222 offset += file->f_pos;
223 break;
224 case 2:
225 offset += NVRAM_BYTES;
226 break;
229 return (offset >= 0) ? (file->f_pos = offset) : -EINVAL;
232 static ssize_t nvram_read(struct file *file, char __user *buf,
233 size_t count, loff_t *ppos)
235 unsigned char contents[NVRAM_BYTES];
236 unsigned i = *ppos;
237 unsigned char *tmp;
239 spin_lock_irq(&rtc_lock);
241 if (!__nvram_check_checksum())
242 goto checksum_err;
244 for (tmp = contents; count-- > 0 && i < NVRAM_BYTES; ++i, ++tmp)
245 *tmp = __nvram_read_byte(i);
247 spin_unlock_irq(&rtc_lock);
249 if (copy_to_user(buf, contents, tmp - contents))
250 return -EFAULT;
252 *ppos = i;
254 return tmp - contents;
256 checksum_err:
257 spin_unlock_irq(&rtc_lock);
258 return -EIO;
261 static ssize_t nvram_write(struct file *file, const char __user *buf,
262 size_t count, loff_t *ppos)
264 unsigned char contents[NVRAM_BYTES];
265 unsigned i = *ppos;
266 unsigned char *tmp;
268 if (i >= NVRAM_BYTES)
269 return 0; /* Past EOF */
271 if (count > NVRAM_BYTES - i)
272 count = NVRAM_BYTES - i;
273 if (count > NVRAM_BYTES)
274 return -EFAULT; /* Can't happen, but prove it to gcc */
276 if (copy_from_user(contents, buf, count))
277 return -EFAULT;
279 spin_lock_irq(&rtc_lock);
281 if (!__nvram_check_checksum())
282 goto checksum_err;
284 for (tmp = contents; count--; ++i, ++tmp)
285 __nvram_write_byte(*tmp, i);
287 __nvram_set_checksum();
289 spin_unlock_irq(&rtc_lock);
291 *ppos = i;
293 return tmp - contents;
295 checksum_err:
296 spin_unlock_irq(&rtc_lock);
297 return -EIO;
300 static long nvram_ioctl(struct file *file, unsigned int cmd,
301 unsigned long arg)
303 int i;
305 switch (cmd) {
307 case NVRAM_INIT:
308 /* initialize NVRAM contents and checksum */
309 if (!capable(CAP_SYS_ADMIN))
310 return -EACCES;
312 mutex_lock(&nvram_mutex);
313 spin_lock_irq(&rtc_lock);
315 for (i = 0; i < NVRAM_BYTES; ++i)
316 __nvram_write_byte(0, i);
317 __nvram_set_checksum();
319 spin_unlock_irq(&rtc_lock);
320 mutex_unlock(&nvram_mutex);
321 return 0;
323 case NVRAM_SETCKS:
324 /* just set checksum, contents unchanged (maybe useful after
325 * checksum garbaged somehow...) */
326 if (!capable(CAP_SYS_ADMIN))
327 return -EACCES;
329 mutex_lock(&nvram_mutex);
330 spin_lock_irq(&rtc_lock);
331 __nvram_set_checksum();
332 spin_unlock_irq(&rtc_lock);
333 mutex_unlock(&nvram_mutex);
334 return 0;
336 default:
337 return -ENOTTY;
341 static int nvram_open(struct inode *inode, struct file *file)
343 spin_lock(&nvram_state_lock);
345 if ((nvram_open_cnt && (file->f_flags & O_EXCL)) ||
346 (nvram_open_mode & NVRAM_EXCL) ||
347 ((file->f_mode & FMODE_WRITE) && (nvram_open_mode & NVRAM_WRITE))) {
348 spin_unlock(&nvram_state_lock);
349 return -EBUSY;
352 if (file->f_flags & O_EXCL)
353 nvram_open_mode |= NVRAM_EXCL;
354 if (file->f_mode & FMODE_WRITE)
355 nvram_open_mode |= NVRAM_WRITE;
356 nvram_open_cnt++;
358 spin_unlock(&nvram_state_lock);
360 return 0;
363 static int nvram_release(struct inode *inode, struct file *file)
365 spin_lock(&nvram_state_lock);
367 nvram_open_cnt--;
369 /* if only one instance is open, clear the EXCL bit */
370 if (nvram_open_mode & NVRAM_EXCL)
371 nvram_open_mode &= ~NVRAM_EXCL;
372 if (file->f_mode & FMODE_WRITE)
373 nvram_open_mode &= ~NVRAM_WRITE;
375 spin_unlock(&nvram_state_lock);
377 return 0;
380 #ifndef CONFIG_PROC_FS
381 static int nvram_add_proc_fs(void)
383 return 0;
386 #else
388 static int nvram_proc_read(struct seq_file *seq, void *offset)
390 unsigned char contents[NVRAM_BYTES];
391 int i = 0;
393 spin_lock_irq(&rtc_lock);
394 for (i = 0; i < NVRAM_BYTES; ++i)
395 contents[i] = __nvram_read_byte(i);
396 spin_unlock_irq(&rtc_lock);
398 mach_proc_infos(contents, seq, offset);
400 return 0;
403 static int nvram_proc_open(struct inode *inode, struct file *file)
405 return single_open(file, nvram_proc_read, NULL);
408 static const struct file_operations nvram_proc_fops = {
409 .owner = THIS_MODULE,
410 .open = nvram_proc_open,
411 .read = seq_read,
412 .llseek = seq_lseek,
413 .release = single_release,
416 static int nvram_add_proc_fs(void)
418 if (!proc_create("driver/nvram", 0, NULL, &nvram_proc_fops))
419 return -ENOMEM;
420 return 0;
423 #endif /* CONFIG_PROC_FS */
425 static const struct file_operations nvram_fops = {
426 .owner = THIS_MODULE,
427 .llseek = nvram_llseek,
428 .read = nvram_read,
429 .write = nvram_write,
430 .unlocked_ioctl = nvram_ioctl,
431 .open = nvram_open,
432 .release = nvram_release,
435 static struct miscdevice nvram_dev = {
436 NVRAM_MINOR,
437 "nvram",
438 &nvram_fops
441 static int __init nvram_init(void)
443 int ret;
445 /* First test whether the driver should init at all */
446 if (!CHECK_DRIVER_INIT())
447 return -ENODEV;
449 ret = misc_register(&nvram_dev);
450 if (ret) {
451 printk(KERN_ERR "nvram: can't misc_register on minor=%d\n",
452 NVRAM_MINOR);
453 goto out;
455 ret = nvram_add_proc_fs();
456 if (ret) {
457 printk(KERN_ERR "nvram: can't create /proc/driver/nvram\n");
458 goto outmisc;
460 ret = 0;
461 printk(KERN_INFO "Non-volatile memory driver v" NVRAM_VERSION "\n");
462 out:
463 return ret;
464 outmisc:
465 misc_deregister(&nvram_dev);
466 goto out;
469 static void __exit nvram_cleanup_module(void)
471 remove_proc_entry("driver/nvram", NULL);
472 misc_deregister(&nvram_dev);
475 module_init(nvram_init);
476 module_exit(nvram_cleanup_module);
479 * Machine specific functions
482 #if MACH == PC
484 static int pc_check_checksum(void)
486 int i;
487 unsigned short sum = 0;
488 unsigned short expect;
490 for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i)
491 sum += __nvram_read_byte(i);
492 expect = __nvram_read_byte(PC_CKS_LOC)<<8 |
493 __nvram_read_byte(PC_CKS_LOC+1);
494 return (sum & 0xffff) == expect;
497 static void pc_set_checksum(void)
499 int i;
500 unsigned short sum = 0;
502 for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i)
503 sum += __nvram_read_byte(i);
504 __nvram_write_byte(sum >> 8, PC_CKS_LOC);
505 __nvram_write_byte(sum & 0xff, PC_CKS_LOC + 1);
508 #ifdef CONFIG_PROC_FS
510 static char *floppy_types[] = {
511 "none", "5.25'' 360k", "5.25'' 1.2M", "3.5'' 720k", "3.5'' 1.44M",
512 "3.5'' 2.88M", "3.5'' 2.88M"
515 static char *gfx_types[] = {
516 "EGA, VGA, ... (with BIOS)",
517 "CGA (40 cols)",
518 "CGA (80 cols)",
519 "monochrome",
522 static void pc_proc_infos(unsigned char *nvram, struct seq_file *seq,
523 void *offset)
525 int checksum;
526 int type;
528 spin_lock_irq(&rtc_lock);
529 checksum = __nvram_check_checksum();
530 spin_unlock_irq(&rtc_lock);
532 seq_printf(seq, "Checksum status: %svalid\n", checksum ? "" : "not ");
534 seq_printf(seq, "# floppies : %d\n",
535 (nvram[6] & 1) ? (nvram[6] >> 6) + 1 : 0);
536 seq_printf(seq, "Floppy 0 type : ");
537 type = nvram[2] >> 4;
538 if (type < ARRAY_SIZE(floppy_types))
539 seq_printf(seq, "%s\n", floppy_types[type]);
540 else
541 seq_printf(seq, "%d (unknown)\n", type);
542 seq_printf(seq, "Floppy 1 type : ");
543 type = nvram[2] & 0x0f;
544 if (type < ARRAY_SIZE(floppy_types))
545 seq_printf(seq, "%s\n", floppy_types[type]);
546 else
547 seq_printf(seq, "%d (unknown)\n", type);
549 seq_printf(seq, "HD 0 type : ");
550 type = nvram[4] >> 4;
551 if (type)
552 seq_printf(seq, "%02x\n", type == 0x0f ? nvram[11] : type);
553 else
554 seq_printf(seq, "none\n");
556 seq_printf(seq, "HD 1 type : ");
557 type = nvram[4] & 0x0f;
558 if (type)
559 seq_printf(seq, "%02x\n", type == 0x0f ? nvram[12] : type);
560 else
561 seq_printf(seq, "none\n");
563 seq_printf(seq, "HD type 48 data: %d/%d/%d C/H/S, precomp %d, lz %d\n",
564 nvram[18] | (nvram[19] << 8),
565 nvram[20], nvram[25],
566 nvram[21] | (nvram[22] << 8), nvram[23] | (nvram[24] << 8));
567 seq_printf(seq, "HD type 49 data: %d/%d/%d C/H/S, precomp %d, lz %d\n",
568 nvram[39] | (nvram[40] << 8),
569 nvram[41], nvram[46],
570 nvram[42] | (nvram[43] << 8), nvram[44] | (nvram[45] << 8));
572 seq_printf(seq, "DOS base memory: %d kB\n", nvram[7] | (nvram[8] << 8));
573 seq_printf(seq, "Extended memory: %d kB (configured), %d kB (tested)\n",
574 nvram[9] | (nvram[10] << 8), nvram[34] | (nvram[35] << 8));
576 seq_printf(seq, "Gfx adapter : %s\n",
577 gfx_types[(nvram[6] >> 4) & 3]);
579 seq_printf(seq, "FPU : %sinstalled\n",
580 (nvram[6] & 2) ? "" : "not ");
582 return;
584 #endif
586 #endif /* MACH == PC */
588 #if MACH == ATARI
590 static int atari_check_checksum(void)
592 int i;
593 unsigned char sum = 0;
595 for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i)
596 sum += __nvram_read_byte(i);
597 return (__nvram_read_byte(ATARI_CKS_LOC) == (~sum & 0xff)) &&
598 (__nvram_read_byte(ATARI_CKS_LOC + 1) == (sum & 0xff));
601 static void atari_set_checksum(void)
603 int i;
604 unsigned char sum = 0;
606 for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i)
607 sum += __nvram_read_byte(i);
608 __nvram_write_byte(~sum, ATARI_CKS_LOC);
609 __nvram_write_byte(sum, ATARI_CKS_LOC + 1);
612 #ifdef CONFIG_PROC_FS
614 static struct {
615 unsigned char val;
616 char *name;
617 } boot_prefs[] = {
618 { 0x80, "TOS" },
619 { 0x40, "ASV" },
620 { 0x20, "NetBSD (?)" },
621 { 0x10, "Linux" },
622 { 0x00, "unspecified" }
625 static char *languages[] = {
626 "English (US)",
627 "German",
628 "French",
629 "English (UK)",
630 "Spanish",
631 "Italian",
632 "6 (undefined)",
633 "Swiss (French)",
634 "Swiss (German)"
637 static char *dateformat[] = {
638 "MM%cDD%cYY",
639 "DD%cMM%cYY",
640 "YY%cMM%cDD",
641 "YY%cDD%cMM",
642 "4 (undefined)",
643 "5 (undefined)",
644 "6 (undefined)",
645 "7 (undefined)"
648 static char *colors[] = {
649 "2", "4", "16", "256", "65536", "??", "??", "??"
652 static void atari_proc_infos(unsigned char *nvram, struct seq_file *seq,
653 void *offset)
655 int checksum = nvram_check_checksum();
656 int i;
657 unsigned vmode;
659 seq_printf(seq, "Checksum status : %svalid\n", checksum ? "" : "not ");
661 seq_printf(seq, "Boot preference : ");
662 for (i = ARRAY_SIZE(boot_prefs) - 1; i >= 0; --i) {
663 if (nvram[1] == boot_prefs[i].val) {
664 seq_printf(seq, "%s\n", boot_prefs[i].name);
665 break;
668 if (i < 0)
669 seq_printf(seq, "0x%02x (undefined)\n", nvram[1]);
671 seq_printf(seq, "SCSI arbitration : %s\n",
672 (nvram[16] & 0x80) ? "on" : "off");
673 seq_printf(seq, "SCSI host ID : ");
674 if (nvram[16] & 0x80)
675 seq_printf(seq, "%d\n", nvram[16] & 7);
676 else
677 seq_printf(seq, "n/a\n");
679 /* the following entries are defined only for the Falcon */
680 if ((atari_mch_cookie >> 16) != ATARI_MCH_FALCON)
681 return;
683 seq_printf(seq, "OS language : ");
684 if (nvram[6] < ARRAY_SIZE(languages))
685 seq_printf(seq, "%s\n", languages[nvram[6]]);
686 else
687 seq_printf(seq, "%u (undefined)\n", nvram[6]);
688 seq_printf(seq, "Keyboard language: ");
689 if (nvram[7] < ARRAY_SIZE(languages))
690 seq_printf(seq, "%s\n", languages[nvram[7]]);
691 else
692 seq_printf(seq, "%u (undefined)\n", nvram[7]);
693 seq_printf(seq, "Date format : ");
694 seq_printf(seq, dateformat[nvram[8] & 7],
695 nvram[9] ? nvram[9] : '/', nvram[9] ? nvram[9] : '/');
696 seq_printf(seq, ", %dh clock\n", nvram[8] & 16 ? 24 : 12);
697 seq_printf(seq, "Boot delay : ");
698 if (nvram[10] == 0)
699 seq_printf(seq, "default");
700 else
701 seq_printf(seq, "%ds%s\n", nvram[10],
702 nvram[10] < 8 ? ", no memory test" : "");
704 vmode = (nvram[14] << 8) || nvram[15];
705 seq_printf(seq,
706 "Video mode : %s colors, %d columns, %s %s monitor\n",
707 colors[vmode & 7],
708 vmode & 8 ? 80 : 40,
709 vmode & 16 ? "VGA" : "TV", vmode & 32 ? "PAL" : "NTSC");
710 seq_printf(seq, " %soverscan, compat. mode %s%s\n",
711 vmode & 64 ? "" : "no ",
712 vmode & 128 ? "on" : "off",
713 vmode & 256 ?
714 (vmode & 16 ? ", line doubling" : ", half screen") : "");
716 return;
718 #endif
720 #endif /* MACH == ATARI */
722 MODULE_LICENSE("GPL");
723 MODULE_ALIAS_MISCDEV(NVRAM_MINOR);