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 time.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 #include <asm/system.h> 115 116 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 */ 122 123 static int mach_check_checksum(void); 124 static void mach_set_checksum(void); 125 126 #ifdef CONFIG_PROC_FS 127 static void mach_proc_infos(unsigned char *contents, struct seq_file *seq, 128 void *offset); 129 #endif 130 131 /* 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). 135 * 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. 140 */ 141 142 unsigned char __nvram_read_byte(int i) 143 { 144 return CMOS_READ(NVRAM_FIRST_BYTE + i); 145 } 146 EXPORT_SYMBOL(__nvram_read_byte); 147 148 unsigned char nvram_read_byte(int i) 149 { 150 unsigned long flags; 151 unsigned char c; 152 153 spin_lock_irqsave(&rtc_lock, flags); 154 c = __nvram_read_byte(i); 155 spin_unlock_irqrestore(&rtc_lock, flags); 156 return c; 157 } 158 EXPORT_SYMBOL(nvram_read_byte); 159 160 /* This races nicely with trying to read with checksum checking (nvram_read) */ 161 void __nvram_write_byte(unsigned char c, int i) 162 { 163 CMOS_WRITE(c, NVRAM_FIRST_BYTE + i); 164 } 165 EXPORT_SYMBOL(__nvram_write_byte); 166 167 void nvram_write_byte(unsigned char c, int i) 168 { 169 unsigned long flags; 170 171 spin_lock_irqsave(&rtc_lock, flags); 172 __nvram_write_byte(c, i); 173 spin_unlock_irqrestore(&rtc_lock, flags); 174 } 175 EXPORT_SYMBOL(nvram_write_byte); 176 177 int __nvram_check_checksum(void) 178 { 179 return mach_check_checksum(); 180 } 181 EXPORT_SYMBOL(__nvram_check_checksum); 182 183 int nvram_check_checksum(void) 184 { 185 unsigned long flags; 186 int rv; 187 188 spin_lock_irqsave(&rtc_lock, flags); 189 rv = __nvram_check_checksum(); 190 spin_unlock_irqrestore(&rtc_lock, flags); 191 return rv; 192 } 193 EXPORT_SYMBOL(nvram_check_checksum); 194 195 static void __nvram_set_checksum(void) 196 { 197 mach_set_checksum(); 198 } 199 200 #if 0 201 void nvram_set_checksum(void) 202 { 203 unsigned long flags; 204 205 spin_lock_irqsave(&rtc_lock, flags); 206 __nvram_set_checksum(); 207 spin_unlock_irqrestore(&rtc_lock, flags); 208 } 209 #endif /* 0 */ 210 211 /* 212 * The are the file operation function for user access to /dev/nvram 213 */ 214 215 static loff_t nvram_llseek(struct file *file, loff_t offset, int origin) 216 { 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; 227 default: 228 return -EINVAL; 229 } 230 231 return (offset >= 0) ? (file->f_pos = offset) : -EINVAL; 232 } 233 234 static ssize_t nvram_read(struct file *file, char __user *buf, 235 size_t count, loff_t *ppos) 236 { 237 unsigned char contents[NVRAM_BYTES]; 238 unsigned i = *ppos; 239 unsigned char *tmp; 240 241 spin_lock_irq(&rtc_lock); 242 243 if (!__nvram_check_checksum()) 244 goto checksum_err; 245 246 for (tmp = contents; count-- > 0 && i < NVRAM_BYTES; ++i, ++tmp) 247 *tmp = __nvram_read_byte(i); 248 249 spin_unlock_irq(&rtc_lock); 250 251 if (copy_to_user(buf, contents, tmp - contents)) 252 return -EFAULT; 253 254 *ppos = i; 255 256 return tmp - contents; 257 258 checksum_err: 259 spin_unlock_irq(&rtc_lock); 260 return -EIO; 261 } 262 263 static ssize_t nvram_write(struct file *file, const char __user *buf, 264 size_t count, loff_t *ppos) 265 { 266 unsigned char contents[NVRAM_BYTES]; 267 unsigned i = *ppos; 268 unsigned char *tmp; 269 270 if (i >= NVRAM_BYTES) 271 return 0; /* Past EOF */ 272 273 if (count > NVRAM_BYTES - i) 274 count = NVRAM_BYTES - i; 275 if (count > NVRAM_BYTES) 276 return -EFAULT; /* Can't happen, but prove it to gcc */ 277 278 if (copy_from_user(contents, buf, count)) 279 return -EFAULT; 280 281 spin_lock_irq(&rtc_lock); 282 283 if (!__nvram_check_checksum()) 284 goto checksum_err; 285 286 for (tmp = contents; count--; ++i, ++tmp) 287 __nvram_write_byte(*tmp, i); 288 289 __nvram_set_checksum(); 290 291 spin_unlock_irq(&rtc_lock); 292 293 *ppos = i; 294 295 return tmp - contents; 296 297 checksum_err: 298 spin_unlock_irq(&rtc_lock); 299 return -EIO; 300 } 301 302 static long nvram_ioctl(struct file *file, unsigned int cmd, 303 unsigned long arg) 304 { 305 int i; 306 307 switch (cmd) { 308 309 case NVRAM_INIT: 310 /* initialize NVRAM contents and checksum */ 311 if (!capable(CAP_SYS_ADMIN)) 312 return -EACCES; 313 314 mutex_lock(&nvram_mutex); 315 spin_lock_irq(&rtc_lock); 316 317 for (i = 0; i < NVRAM_BYTES; ++i) 318 __nvram_write_byte(0, i); 319 __nvram_set_checksum(); 320 321 spin_unlock_irq(&rtc_lock); 322 mutex_unlock(&nvram_mutex); 323 return 0; 324 325 case NVRAM_SETCKS: 326 /* just set checksum, contents unchanged (maybe useful after 327 * checksum garbaged somehow...) */ 328 if (!capable(CAP_SYS_ADMIN)) 329 return -EACCES; 330 331 mutex_lock(&nvram_mutex); 332 spin_lock_irq(&rtc_lock); 333 __nvram_set_checksum(); 334 spin_unlock_irq(&rtc_lock); 335 mutex_unlock(&nvram_mutex); 336 return 0; 337 338 default: 339 return -ENOTTY; 340 } 341 } 342 343 static int nvram_open(struct inode *inode, struct file *file) 344 { 345 spin_lock(&nvram_state_lock); 346 347 if ((nvram_open_cnt && (file->f_flags & O_EXCL)) || 348 (nvram_open_mode & NVRAM_EXCL) || 349 ((file->f_mode & FMODE_WRITE) && (nvram_open_mode & NVRAM_WRITE))) { 350 spin_unlock(&nvram_state_lock); 351 return -EBUSY; 352 } 353 354 if (file->f_flags & O_EXCL) 355 nvram_open_mode |= NVRAM_EXCL; 356 if (file->f_mode & FMODE_WRITE) 357 nvram_open_mode |= NVRAM_WRITE; 358 nvram_open_cnt++; 359 360 spin_unlock(&nvram_state_lock); 361 362 return 0; 363 } 364 365 static int nvram_release(struct inode *inode, struct file *file) 366 { 367 spin_lock(&nvram_state_lock); 368 369 nvram_open_cnt--; 370 371 /* if only one instance is open, clear the EXCL bit */ 372 if (nvram_open_mode & NVRAM_EXCL) 373 nvram_open_mode &= ~NVRAM_EXCL; 374 if (file->f_mode & FMODE_WRITE) 375 nvram_open_mode &= ~NVRAM_WRITE; 376 377 spin_unlock(&nvram_state_lock); 378 379 return 0; 380 } 381 382 #ifndef CONFIG_PROC_FS 383 static int nvram_add_proc_fs(void) 384 { 385 return 0; 386 } 387 388 #else 389 390 static int nvram_proc_read(struct seq_file *seq, void *offset) 391 { 392 unsigned char contents[NVRAM_BYTES]; 393 int i = 0; 394 395 spin_lock_irq(&rtc_lock); 396 for (i = 0; i < NVRAM_BYTES; ++i) 397 contents[i] = __nvram_read_byte(i); 398 spin_unlock_irq(&rtc_lock); 399 400 mach_proc_infos(contents, seq, offset); 401 402 return 0; 403 } 404 405 static int nvram_proc_open(struct inode *inode, struct file *file) 406 { 407 return single_open(file, nvram_proc_read, NULL); 408 } 409 410 static const struct file_operations nvram_proc_fops = { 411 .owner = THIS_MODULE, 412 .open = nvram_proc_open, 413 .read = seq_read, 414 .llseek = seq_lseek, 415 .release = single_release, 416 }; 417 418 static int nvram_add_proc_fs(void) 419 { 420 if (!proc_create("driver/nvram", 0, NULL, &nvram_proc_fops)) 421 return -ENOMEM; 422 return 0; 423 } 424 425 #endif /* CONFIG_PROC_FS */ 426 427 static const struct file_operations nvram_fops = { 428 .owner = THIS_MODULE, 429 .llseek = nvram_llseek, 430 .read = nvram_read, 431 .write = nvram_write, 432 .unlocked_ioctl = nvram_ioctl, 433 .open = nvram_open, 434 .release = nvram_release, 435 }; 436 437 static struct miscdevice nvram_dev = { 438 NVRAM_MINOR, 439 "nvram", 440 &nvram_fops 441 }; 442 443 static int __init nvram_init(void) 444 { 445 int ret; 446 447 /* First test whether the driver should init at all */ 448 if (!CHECK_DRIVER_INIT()) 449 return -ENODEV; 450 451 ret = misc_register(&nvram_dev); 452 if (ret) { 453 printk(KERN_ERR "nvram: can't misc_register on minor=%d\n", 454 NVRAM_MINOR); 455 goto out; 456 } 457 ret = nvram_add_proc_fs(); 458 if (ret) { 459 printk(KERN_ERR "nvram: can't create /proc/driver/nvram\n"); 460 goto outmisc; 461 } 462 ret = 0; 463 printk(KERN_INFO "Non-volatile memory driver v" NVRAM_VERSION "\n"); 464 out: 465 return ret; 466 outmisc: 467 misc_deregister(&nvram_dev); 468 goto out; 469 } 470 471 static void __exit nvram_cleanup_module(void) 472 { 473 remove_proc_entry("driver/nvram", NULL); 474 misc_deregister(&nvram_dev); 475 } 476 477 module_init(nvram_init); 478 module_exit(nvram_cleanup_module); 479 480 /* 481 * Machine specific functions 482 */ 483 484 #if MACH == PC 485 486 static int pc_check_checksum(void) 487 { 488 int i; 489 unsigned short sum = 0; 490 unsigned short expect; 491 492 for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i) 493 sum += __nvram_read_byte(i); 494 expect = __nvram_read_byte(PC_CKS_LOC)<<8 | 495 __nvram_read_byte(PC_CKS_LOC+1); 496 return (sum & 0xffff) == expect; 497 } 498 499 static void pc_set_checksum(void) 500 { 501 int i; 502 unsigned short sum = 0; 503 504 for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i) 505 sum += __nvram_read_byte(i); 506 __nvram_write_byte(sum >> 8, PC_CKS_LOC); 507 __nvram_write_byte(sum & 0xff, PC_CKS_LOC + 1); 508 } 509 510 #ifdef CONFIG_PROC_FS 511 512 static char *floppy_types[] = { 513 "none", "5.25'' 360k", "5.25'' 1.2M", "3.5'' 720k", "3.5'' 1.44M", 514 "3.5'' 2.88M", "3.5'' 2.88M" 515 }; 516 517 static char *gfx_types[] = { 518 "EGA, VGA, ... (with BIOS)", 519 "CGA (40 cols)", 520 "CGA (80 cols)", 521 "monochrome", 522 }; 523 524 static void pc_proc_infos(unsigned char *nvram, struct seq_file *seq, 525 void *offset) 526 { 527 int checksum; 528 int type; 529 530 spin_lock_irq(&rtc_lock); 531 checksum = __nvram_check_checksum(); 532 spin_unlock_irq(&rtc_lock); 533 534 seq_printf(seq, "Checksum status: %svalid\n", checksum ? "" : "not "); 535 536 seq_printf(seq, "# floppies : %d\n", 537 (nvram[6] & 1) ? (nvram[6] >> 6) + 1 : 0); 538 seq_printf(seq, "Floppy 0 type : "); 539 type = nvram[2] >> 4; 540 if (type < ARRAY_SIZE(floppy_types)) 541 seq_printf(seq, "%s\n", floppy_types[type]); 542 else 543 seq_printf(seq, "%d (unknown)\n", type); 544 seq_printf(seq, "Floppy 1 type : "); 545 type = nvram[2] & 0x0f; 546 if (type < ARRAY_SIZE(floppy_types)) 547 seq_printf(seq, "%s\n", floppy_types[type]); 548 else 549 seq_printf(seq, "%d (unknown)\n", type); 550 551 seq_printf(seq, "HD 0 type : "); 552 type = nvram[4] >> 4; 553 if (type) 554 seq_printf(seq, "%02x\n", type == 0x0f ? nvram[11] : type); 555 else 556 seq_printf(seq, "none\n"); 557 558 seq_printf(seq, "HD 1 type : "); 559 type = nvram[4] & 0x0f; 560 if (type) 561 seq_printf(seq, "%02x\n", type == 0x0f ? nvram[12] : type); 562 else 563 seq_printf(seq, "none\n"); 564 565 seq_printf(seq, "HD type 48 data: %d/%d/%d C/H/S, precomp %d, lz %d\n", 566 nvram[18] | (nvram[19] << 8), 567 nvram[20], nvram[25], 568 nvram[21] | (nvram[22] << 8), nvram[23] | (nvram[24] << 8)); 569 seq_printf(seq, "HD type 49 data: %d/%d/%d C/H/S, precomp %d, lz %d\n", 570 nvram[39] | (nvram[40] << 8), 571 nvram[41], nvram[46], 572 nvram[42] | (nvram[43] << 8), nvram[44] | (nvram[45] << 8)); 573 574 seq_printf(seq, "DOS base memory: %d kB\n", nvram[7] | (nvram[8] << 8)); 575 seq_printf(seq, "Extended memory: %d kB (configured), %d kB (tested)\n", 576 nvram[9] | (nvram[10] << 8), nvram[34] | (nvram[35] << 8)); 577 578 seq_printf(seq, "Gfx adapter : %s\n", 579 gfx_types[(nvram[6] >> 4) & 3]); 580 581 seq_printf(seq, "FPU : %sinstalled\n", 582 (nvram[6] & 2) ? "" : "not "); 583 584 return; 585 } 586 #endif 587 588 #endif /* MACH == PC */ 589 590 #if MACH == ATARI 591 592 static int atari_check_checksum(void) 593 { 594 int i; 595 unsigned char sum = 0; 596 597 for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i) 598 sum += __nvram_read_byte(i); 599 return (__nvram_read_byte(ATARI_CKS_LOC) == (~sum & 0xff)) && 600 (__nvram_read_byte(ATARI_CKS_LOC + 1) == (sum & 0xff)); 601 } 602 603 static void atari_set_checksum(void) 604 { 605 int i; 606 unsigned char sum = 0; 607 608 for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i) 609 sum += __nvram_read_byte(i); 610 __nvram_write_byte(~sum, ATARI_CKS_LOC); 611 __nvram_write_byte(sum, ATARI_CKS_LOC + 1); 612 } 613 614 #ifdef CONFIG_PROC_FS 615 616 static struct { 617 unsigned char val; 618 char *name; 619 } boot_prefs[] = { 620 { 0x80, "TOS" }, 621 { 0x40, "ASV" }, 622 { 0x20, "NetBSD (?)" }, 623 { 0x10, "Linux" }, 624 { 0x00, "unspecified" } 625 }; 626 627 static char *languages[] = { 628 "English (US)", 629 "German", 630 "French", 631 "English (UK)", 632 "Spanish", 633 "Italian", 634 "6 (undefined)", 635 "Swiss (French)", 636 "Swiss (German)" 637 }; 638 639 static char *dateformat[] = { 640 "MM%cDD%cYY", 641 "DD%cMM%cYY", 642 "YY%cMM%cDD", 643 "YY%cDD%cMM", 644 "4 (undefined)", 645 "5 (undefined)", 646 "6 (undefined)", 647 "7 (undefined)" 648 }; 649 650 static char *colors[] = { 651 "2", "4", "16", "256", "65536", "??", "??", "??" 652 }; 653 654 static void atari_proc_infos(unsigned char *nvram, struct seq_file *seq, 655 void *offset) 656 { 657 int checksum = nvram_check_checksum(); 658 int i; 659 unsigned vmode; 660 661 seq_printf(seq, "Checksum status : %svalid\n", checksum ? "" : "not "); 662 663 seq_printf(seq, "Boot preference : "); 664 for (i = ARRAY_SIZE(boot_prefs) - 1; i >= 0; --i) { 665 if (nvram[1] == boot_prefs[i].val) { 666 seq_printf(seq, "%s\n", boot_prefs[i].name); 667 break; 668 } 669 } 670 if (i < 0) 671 seq_printf(seq, "0x%02x (undefined)\n", nvram[1]); 672 673 seq_printf(seq, "SCSI arbitration : %s\n", 674 (nvram[16] & 0x80) ? "on" : "off"); 675 seq_printf(seq, "SCSI host ID : "); 676 if (nvram[16] & 0x80) 677 seq_printf(seq, "%d\n", nvram[16] & 7); 678 else 679 seq_printf(seq, "n/a\n"); 680 681 /* the following entries are defined only for the Falcon */ 682 if ((atari_mch_cookie >> 16) != ATARI_MCH_FALCON) 683 return; 684 685 seq_printf(seq, "OS language : "); 686 if (nvram[6] < ARRAY_SIZE(languages)) 687 seq_printf(seq, "%s\n", languages[nvram[6]]); 688 else 689 seq_printf(seq, "%u (undefined)\n", nvram[6]); 690 seq_printf(seq, "Keyboard language: "); 691 if (nvram[7] < ARRAY_SIZE(languages)) 692 seq_printf(seq, "%s\n", languages[nvram[7]]); 693 else 694 seq_printf(seq, "%u (undefined)\n", nvram[7]); 695 seq_printf(seq, "Date format : "); 696 seq_printf(seq, dateformat[nvram[8] & 7], 697 nvram[9] ? nvram[9] : '/', nvram[9] ? nvram[9] : '/'); 698 seq_printf(seq, ", %dh clock\n", nvram[8] & 16 ? 24 : 12); 699 seq_printf(seq, "Boot delay : "); 700 if (nvram[10] == 0) 701 seq_printf(seq, "default"); 702 else 703 seq_printf(seq, "%ds%s\n", nvram[10], 704 nvram[10] < 8 ? ", no memory test" : ""); 705 706 vmode = (nvram[14] << 8) || nvram[15]; 707 seq_printf(seq, 708 "Video mode : %s colors, %d columns, %s %s monitor\n", 709 colors[vmode & 7], 710 vmode & 8 ? 80 : 40, 711 vmode & 16 ? "VGA" : "TV", vmode & 32 ? "PAL" : "NTSC"); 712 seq_printf(seq, " %soverscan, compat. mode %s%s\n", 713 vmode & 64 ? "" : "no ", 714 vmode & 128 ? "on" : "off", 715 vmode & 256 ? 716 (vmode & 16 ? ", line doubling" : ", half screen") : ""); 717 718 return; 719 } 720 #endif 721 722 #endif /* MACH == ATARI */ 723 724 MODULE_LICENSE("GPL"); 725 MODULE_ALIAS_MISCDEV(NVRAM_MINOR); 726