1 /* 2 * CMOS/NV-RAM driver for Linux 3 * 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) 7 * 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). 12 * 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). 17 * 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!) 23 * 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. 29 * 30 * 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 36 */ 37 38 #define NVRAM_VERSION "1.3" 39 40 #include <linux/module.h> 41 #include <linux/nvram.h> 42 43 #define PC 1 44 #define ATARI 2 45 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 54 55 #if MACH == PC 56 57 /* RTC in a PC */ 58 #define CHECK_DRIVER_INIT() 1 59 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) 65 66 #define mach_check_checksum pc_check_checksum 67 #define mach_set_checksum pc_set_checksum 68 #define mach_proc_infos pc_proc_infos 69 70 #endif 71 72 #if MACH == ATARI 73 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)) 79 80 #define NVRAM_BYTES 50 81 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 87 88 #define mach_check_checksum atari_check_checksum 89 #define mach_set_checksum atari_set_checksum 90 #define mach_proc_infos atari_proc_infos 91 92 #endif 93 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 kernel/time/ntp.c vs. this driver.) 98 */ 99 100 #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> 113 114 115 static DEFINE_MUTEX(nvram_mutex); 116 static DEFINE_SPINLOCK(nvram_state_lock); 117 static int nvram_open_cnt; /* #times opened */ 118 static int nvram_open_mode; /* special open modes */ 119 #define NVRAM_WRITE 1 /* opened for writing (exclusive) */ 120 #define NVRAM_EXCL 2 /* opened with O_EXCL */ 121 122 static int mach_check_checksum(void); 123 static void mach_set_checksum(void); 124 125 #ifdef CONFIG_PROC_FS 126 static void mach_proc_infos(unsigned char *contents, struct seq_file *seq, 127 void *offset); 128 #endif 129 130 /* 131 * These functions are provided to be called internally or by other parts of 132 * the kernel. It's up to the caller to ensure correct checksum before reading 133 * or after writing (needs to be done only once). 134 * 135 * It is worth noting that these functions all access bytes of general 136 * purpose memory in the NVRAM - that is to say, they all add the 137 * NVRAM_FIRST_BYTE offset. Pass them offsets into NVRAM as if you did not 138 * know about the RTC cruft. 139 */ 140 141 unsigned char __nvram_read_byte(int i) 142 { 143 return CMOS_READ(NVRAM_FIRST_BYTE + i); 144 } 145 EXPORT_SYMBOL(__nvram_read_byte); 146 147 unsigned char nvram_read_byte(int i) 148 { 149 unsigned long flags; 150 unsigned char c; 151 152 spin_lock_irqsave(&rtc_lock, flags); 153 c = __nvram_read_byte(i); 154 spin_unlock_irqrestore(&rtc_lock, flags); 155 return c; 156 } 157 EXPORT_SYMBOL(nvram_read_byte); 158 159 /* This races nicely with trying to read with checksum checking (nvram_read) */ 160 void __nvram_write_byte(unsigned char c, int i) 161 { 162 CMOS_WRITE(c, NVRAM_FIRST_BYTE + i); 163 } 164 EXPORT_SYMBOL(__nvram_write_byte); 165 166 void nvram_write_byte(unsigned char c, int i) 167 { 168 unsigned long flags; 169 170 spin_lock_irqsave(&rtc_lock, flags); 171 __nvram_write_byte(c, i); 172 spin_unlock_irqrestore(&rtc_lock, flags); 173 } 174 EXPORT_SYMBOL(nvram_write_byte); 175 176 int __nvram_check_checksum(void) 177 { 178 return mach_check_checksum(); 179 } 180 EXPORT_SYMBOL(__nvram_check_checksum); 181 182 int nvram_check_checksum(void) 183 { 184 unsigned long flags; 185 int rv; 186 187 spin_lock_irqsave(&rtc_lock, flags); 188 rv = __nvram_check_checksum(); 189 spin_unlock_irqrestore(&rtc_lock, flags); 190 return rv; 191 } 192 EXPORT_SYMBOL(nvram_check_checksum); 193 194 static void __nvram_set_checksum(void) 195 { 196 mach_set_checksum(); 197 } 198 199 #if 0 200 void nvram_set_checksum(void) 201 { 202 unsigned long flags; 203 204 spin_lock_irqsave(&rtc_lock, flags); 205 __nvram_set_checksum(); 206 spin_unlock_irqrestore(&rtc_lock, flags); 207 } 208 #endif /* 0 */ 209 210 /* 211 * The are the file operation function for user access to /dev/nvram 212 */ 213 214 static loff_t nvram_llseek(struct file *file, loff_t offset, int origin) 215 { 216 switch (origin) { 217 case 0: 218 /* nothing to do */ 219 break; 220 case 1: 221 offset += file->f_pos; 222 break; 223 case 2: 224 offset += NVRAM_BYTES; 225 break; 226 default: 227 return -EINVAL; 228 } 229 230 return (offset >= 0) ? (file->f_pos = offset) : -EINVAL; 231 } 232 233 static ssize_t nvram_read(struct file *file, char __user *buf, 234 size_t count, loff_t *ppos) 235 { 236 unsigned char contents[NVRAM_BYTES]; 237 unsigned i = *ppos; 238 unsigned char *tmp; 239 240 spin_lock_irq(&rtc_lock); 241 242 if (!__nvram_check_checksum()) 243 goto checksum_err; 244 245 for (tmp = contents; count-- > 0 && i < NVRAM_BYTES; ++i, ++tmp) 246 *tmp = __nvram_read_byte(i); 247 248 spin_unlock_irq(&rtc_lock); 249 250 if (copy_to_user(buf, contents, tmp - contents)) 251 return -EFAULT; 252 253 *ppos = i; 254 255 return tmp - contents; 256 257 checksum_err: 258 spin_unlock_irq(&rtc_lock); 259 return -EIO; 260 } 261 262 static ssize_t nvram_write(struct file *file, const char __user *buf, 263 size_t count, loff_t *ppos) 264 { 265 unsigned char contents[NVRAM_BYTES]; 266 unsigned i = *ppos; 267 unsigned char *tmp; 268 269 if (i >= NVRAM_BYTES) 270 return 0; /* Past EOF */ 271 272 if (count > NVRAM_BYTES - i) 273 count = NVRAM_BYTES - i; 274 if (count > NVRAM_BYTES) 275 return -EFAULT; /* Can't happen, but prove it to gcc */ 276 277 if (copy_from_user(contents, buf, count)) 278 return -EFAULT; 279 280 spin_lock_irq(&rtc_lock); 281 282 if (!__nvram_check_checksum()) 283 goto checksum_err; 284 285 for (tmp = contents; count--; ++i, ++tmp) 286 __nvram_write_byte(*tmp, i); 287 288 __nvram_set_checksum(); 289 290 spin_unlock_irq(&rtc_lock); 291 292 *ppos = i; 293 294 return tmp - contents; 295 296 checksum_err: 297 spin_unlock_irq(&rtc_lock); 298 return -EIO; 299 } 300 301 static long nvram_ioctl(struct file *file, unsigned int cmd, 302 unsigned long arg) 303 { 304 int i; 305 306 switch (cmd) { 307 308 case NVRAM_INIT: 309 /* initialize NVRAM contents and checksum */ 310 if (!capable(CAP_SYS_ADMIN)) 311 return -EACCES; 312 313 mutex_lock(&nvram_mutex); 314 spin_lock_irq(&rtc_lock); 315 316 for (i = 0; i < NVRAM_BYTES; ++i) 317 __nvram_write_byte(0, i); 318 __nvram_set_checksum(); 319 320 spin_unlock_irq(&rtc_lock); 321 mutex_unlock(&nvram_mutex); 322 return 0; 323 324 case NVRAM_SETCKS: 325 /* just set checksum, contents unchanged (maybe useful after 326 * checksum garbaged somehow...) */ 327 if (!capable(CAP_SYS_ADMIN)) 328 return -EACCES; 329 330 mutex_lock(&nvram_mutex); 331 spin_lock_irq(&rtc_lock); 332 __nvram_set_checksum(); 333 spin_unlock_irq(&rtc_lock); 334 mutex_unlock(&nvram_mutex); 335 return 0; 336 337 default: 338 return -ENOTTY; 339 } 340 } 341 342 static int nvram_open(struct inode *inode, struct file *file) 343 { 344 spin_lock(&nvram_state_lock); 345 346 if ((nvram_open_cnt && (file->f_flags & O_EXCL)) || 347 (nvram_open_mode & NVRAM_EXCL) || 348 ((file->f_mode & FMODE_WRITE) && (nvram_open_mode & NVRAM_WRITE))) { 349 spin_unlock(&nvram_state_lock); 350 return -EBUSY; 351 } 352 353 if (file->f_flags & O_EXCL) 354 nvram_open_mode |= NVRAM_EXCL; 355 if (file->f_mode & FMODE_WRITE) 356 nvram_open_mode |= NVRAM_WRITE; 357 nvram_open_cnt++; 358 359 spin_unlock(&nvram_state_lock); 360 361 return 0; 362 } 363 364 static int nvram_release(struct inode *inode, struct file *file) 365 { 366 spin_lock(&nvram_state_lock); 367 368 nvram_open_cnt--; 369 370 /* if only one instance is open, clear the EXCL bit */ 371 if (nvram_open_mode & NVRAM_EXCL) 372 nvram_open_mode &= ~NVRAM_EXCL; 373 if (file->f_mode & FMODE_WRITE) 374 nvram_open_mode &= ~NVRAM_WRITE; 375 376 spin_unlock(&nvram_state_lock); 377 378 return 0; 379 } 380 381 #ifndef CONFIG_PROC_FS 382 static int nvram_add_proc_fs(void) 383 { 384 return 0; 385 } 386 387 #else 388 389 static int nvram_proc_read(struct seq_file *seq, void *offset) 390 { 391 unsigned char contents[NVRAM_BYTES]; 392 int i = 0; 393 394 spin_lock_irq(&rtc_lock); 395 for (i = 0; i < NVRAM_BYTES; ++i) 396 contents[i] = __nvram_read_byte(i); 397 spin_unlock_irq(&rtc_lock); 398 399 mach_proc_infos(contents, seq, offset); 400 401 return 0; 402 } 403 404 static int nvram_proc_open(struct inode *inode, struct file *file) 405 { 406 return single_open(file, nvram_proc_read, NULL); 407 } 408 409 static const struct file_operations nvram_proc_fops = { 410 .owner = THIS_MODULE, 411 .open = nvram_proc_open, 412 .read = seq_read, 413 .llseek = seq_lseek, 414 .release = single_release, 415 }; 416 417 static int nvram_add_proc_fs(void) 418 { 419 if (!proc_create("driver/nvram", 0, NULL, &nvram_proc_fops)) 420 return -ENOMEM; 421 return 0; 422 } 423 424 #endif /* CONFIG_PROC_FS */ 425 426 static const struct file_operations nvram_fops = { 427 .owner = THIS_MODULE, 428 .llseek = nvram_llseek, 429 .read = nvram_read, 430 .write = nvram_write, 431 .unlocked_ioctl = nvram_ioctl, 432 .open = nvram_open, 433 .release = nvram_release, 434 }; 435 436 static struct miscdevice nvram_dev = { 437 NVRAM_MINOR, 438 "nvram", 439 &nvram_fops 440 }; 441 442 static int __init nvram_init(void) 443 { 444 int ret; 445 446 /* First test whether the driver should init at all */ 447 if (!CHECK_DRIVER_INIT()) 448 return -ENODEV; 449 450 ret = misc_register(&nvram_dev); 451 if (ret) { 452 printk(KERN_ERR "nvram: can't misc_register on minor=%d\n", 453 NVRAM_MINOR); 454 goto out; 455 } 456 ret = nvram_add_proc_fs(); 457 if (ret) { 458 printk(KERN_ERR "nvram: can't create /proc/driver/nvram\n"); 459 goto outmisc; 460 } 461 ret = 0; 462 printk(KERN_INFO "Non-volatile memory driver v" NVRAM_VERSION "\n"); 463 out: 464 return ret; 465 outmisc: 466 misc_deregister(&nvram_dev); 467 goto out; 468 } 469 470 static void __exit nvram_cleanup_module(void) 471 { 472 remove_proc_entry("driver/nvram", NULL); 473 misc_deregister(&nvram_dev); 474 } 475 476 module_init(nvram_init); 477 module_exit(nvram_cleanup_module); 478 479 /* 480 * Machine specific functions 481 */ 482 483 #if MACH == PC 484 485 static int pc_check_checksum(void) 486 { 487 int i; 488 unsigned short sum = 0; 489 unsigned short expect; 490 491 for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i) 492 sum += __nvram_read_byte(i); 493 expect = __nvram_read_byte(PC_CKS_LOC)<<8 | 494 __nvram_read_byte(PC_CKS_LOC+1); 495 return (sum & 0xffff) == expect; 496 } 497 498 static void pc_set_checksum(void) 499 { 500 int i; 501 unsigned short sum = 0; 502 503 for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i) 504 sum += __nvram_read_byte(i); 505 __nvram_write_byte(sum >> 8, PC_CKS_LOC); 506 __nvram_write_byte(sum & 0xff, PC_CKS_LOC + 1); 507 } 508 509 #ifdef CONFIG_PROC_FS 510 511 static char *floppy_types[] = { 512 "none", "5.25'' 360k", "5.25'' 1.2M", "3.5'' 720k", "3.5'' 1.44M", 513 "3.5'' 2.88M", "3.5'' 2.88M" 514 }; 515 516 static char *gfx_types[] = { 517 "EGA, VGA, ... (with BIOS)", 518 "CGA (40 cols)", 519 "CGA (80 cols)", 520 "monochrome", 521 }; 522 523 static void pc_proc_infos(unsigned char *nvram, struct seq_file *seq, 524 void *offset) 525 { 526 int checksum; 527 int type; 528 529 spin_lock_irq(&rtc_lock); 530 checksum = __nvram_check_checksum(); 531 spin_unlock_irq(&rtc_lock); 532 533 seq_printf(seq, "Checksum status: %svalid\n", checksum ? "" : "not "); 534 535 seq_printf(seq, "# floppies : %d\n", 536 (nvram[6] & 1) ? (nvram[6] >> 6) + 1 : 0); 537 seq_printf(seq, "Floppy 0 type : "); 538 type = nvram[2] >> 4; 539 if (type < ARRAY_SIZE(floppy_types)) 540 seq_printf(seq, "%s\n", floppy_types[type]); 541 else 542 seq_printf(seq, "%d (unknown)\n", type); 543 seq_printf(seq, "Floppy 1 type : "); 544 type = nvram[2] & 0x0f; 545 if (type < ARRAY_SIZE(floppy_types)) 546 seq_printf(seq, "%s\n", floppy_types[type]); 547 else 548 seq_printf(seq, "%d (unknown)\n", type); 549 550 seq_printf(seq, "HD 0 type : "); 551 type = nvram[4] >> 4; 552 if (type) 553 seq_printf(seq, "%02x\n", type == 0x0f ? nvram[11] : type); 554 else 555 seq_printf(seq, "none\n"); 556 557 seq_printf(seq, "HD 1 type : "); 558 type = nvram[4] & 0x0f; 559 if (type) 560 seq_printf(seq, "%02x\n", type == 0x0f ? nvram[12] : type); 561 else 562 seq_printf(seq, "none\n"); 563 564 seq_printf(seq, "HD type 48 data: %d/%d/%d C/H/S, precomp %d, lz %d\n", 565 nvram[18] | (nvram[19] << 8), 566 nvram[20], nvram[25], 567 nvram[21] | (nvram[22] << 8), nvram[23] | (nvram[24] << 8)); 568 seq_printf(seq, "HD type 49 data: %d/%d/%d C/H/S, precomp %d, lz %d\n", 569 nvram[39] | (nvram[40] << 8), 570 nvram[41], nvram[46], 571 nvram[42] | (nvram[43] << 8), nvram[44] | (nvram[45] << 8)); 572 573 seq_printf(seq, "DOS base memory: %d kB\n", nvram[7] | (nvram[8] << 8)); 574 seq_printf(seq, "Extended memory: %d kB (configured), %d kB (tested)\n", 575 nvram[9] | (nvram[10] << 8), nvram[34] | (nvram[35] << 8)); 576 577 seq_printf(seq, "Gfx adapter : %s\n", 578 gfx_types[(nvram[6] >> 4) & 3]); 579 580 seq_printf(seq, "FPU : %sinstalled\n", 581 (nvram[6] & 2) ? "" : "not "); 582 583 return; 584 } 585 #endif 586 587 #endif /* MACH == PC */ 588 589 #if MACH == ATARI 590 591 static int atari_check_checksum(void) 592 { 593 int i; 594 unsigned char sum = 0; 595 596 for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i) 597 sum += __nvram_read_byte(i); 598 return (__nvram_read_byte(ATARI_CKS_LOC) == (~sum & 0xff)) && 599 (__nvram_read_byte(ATARI_CKS_LOC + 1) == (sum & 0xff)); 600 } 601 602 static void atari_set_checksum(void) 603 { 604 int i; 605 unsigned char sum = 0; 606 607 for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i) 608 sum += __nvram_read_byte(i); 609 __nvram_write_byte(~sum, ATARI_CKS_LOC); 610 __nvram_write_byte(sum, ATARI_CKS_LOC + 1); 611 } 612 613 #ifdef CONFIG_PROC_FS 614 615 static struct { 616 unsigned char val; 617 char *name; 618 } boot_prefs[] = { 619 { 0x80, "TOS" }, 620 { 0x40, "ASV" }, 621 { 0x20, "NetBSD (?)" }, 622 { 0x10, "Linux" }, 623 { 0x00, "unspecified" } 624 }; 625 626 static char *languages[] = { 627 "English (US)", 628 "German", 629 "French", 630 "English (UK)", 631 "Spanish", 632 "Italian", 633 "6 (undefined)", 634 "Swiss (French)", 635 "Swiss (German)" 636 }; 637 638 static char *dateformat[] = { 639 "MM%cDD%cYY", 640 "DD%cMM%cYY", 641 "YY%cMM%cDD", 642 "YY%cDD%cMM", 643 "4 (undefined)", 644 "5 (undefined)", 645 "6 (undefined)", 646 "7 (undefined)" 647 }; 648 649 static char *colors[] = { 650 "2", "4", "16", "256", "65536", "??", "??", "??" 651 }; 652 653 static void atari_proc_infos(unsigned char *nvram, struct seq_file *seq, 654 void *offset) 655 { 656 int checksum = nvram_check_checksum(); 657 int i; 658 unsigned vmode; 659 660 seq_printf(seq, "Checksum status : %svalid\n", checksum ? "" : "not "); 661 662 seq_printf(seq, "Boot preference : "); 663 for (i = ARRAY_SIZE(boot_prefs) - 1; i >= 0; --i) { 664 if (nvram[1] == boot_prefs[i].val) { 665 seq_printf(seq, "%s\n", boot_prefs[i].name); 666 break; 667 } 668 } 669 if (i < 0) 670 seq_printf(seq, "0x%02x (undefined)\n", nvram[1]); 671 672 seq_printf(seq, "SCSI arbitration : %s\n", 673 (nvram[16] & 0x80) ? "on" : "off"); 674 seq_printf(seq, "SCSI host ID : "); 675 if (nvram[16] & 0x80) 676 seq_printf(seq, "%d\n", nvram[16] & 7); 677 else 678 seq_printf(seq, "n/a\n"); 679 680 /* the following entries are defined only for the Falcon */ 681 if ((atari_mch_cookie >> 16) != ATARI_MCH_FALCON) 682 return; 683 684 seq_printf(seq, "OS language : "); 685 if (nvram[6] < ARRAY_SIZE(languages)) 686 seq_printf(seq, "%s\n", languages[nvram[6]]); 687 else 688 seq_printf(seq, "%u (undefined)\n", nvram[6]); 689 seq_printf(seq, "Keyboard language: "); 690 if (nvram[7] < ARRAY_SIZE(languages)) 691 seq_printf(seq, "%s\n", languages[nvram[7]]); 692 else 693 seq_printf(seq, "%u (undefined)\n", nvram[7]); 694 seq_printf(seq, "Date format : "); 695 seq_printf(seq, dateformat[nvram[8] & 7], 696 nvram[9] ? nvram[9] : '/', nvram[9] ? nvram[9] : '/'); 697 seq_printf(seq, ", %dh clock\n", nvram[8] & 16 ? 24 : 12); 698 seq_printf(seq, "Boot delay : "); 699 if (nvram[10] == 0) 700 seq_printf(seq, "default"); 701 else 702 seq_printf(seq, "%ds%s\n", nvram[10], 703 nvram[10] < 8 ? ", no memory test" : ""); 704 705 vmode = (nvram[14] << 8) || nvram[15]; 706 seq_printf(seq, 707 "Video mode : %s colors, %d columns, %s %s monitor\n", 708 colors[vmode & 7], 709 vmode & 8 ? 80 : 40, 710 vmode & 16 ? "VGA" : "TV", vmode & 32 ? "PAL" : "NTSC"); 711 seq_printf(seq, " %soverscan, compat. mode %s%s\n", 712 vmode & 64 ? "" : "no ", 713 vmode & 128 ? "on" : "off", 714 vmode & 256 ? 715 (vmode & 16 ? ", line doubling" : ", half screen") : ""); 716 717 return; 718 } 719 #endif 720 721 #endif /* MACH == ATARI */ 722 723 MODULE_LICENSE("GPL"); 724 MODULE_ALIAS_MISCDEV(NVRAM_MINOR); 725