drivers/video/arcfb.c

   1 /*
   2  * linux/drivers/video/arcfb.c -- FB driver for Arc monochrome LCD board
   3  *
   4  * Copyright (C) 2005, Jaya Kumar <jayalk@intworks.biz>
   5  * http://www.intworks.biz/arclcd
   6  *
   7  * This file is subject to the terms and conditions of the GNU General Public
   8  * License. See the file COPYING in the main directory of this archive for
   9  * more details.
  10  *
  11  * Layout is based on skeletonfb.c by James Simmons and Geert Uytterhoeven.
  12  *
  13  * This driver was written to be used with the Arc LCD board. Arc uses a
  14  * set of KS108 chips that control individual 64x64 LCD matrices. The board
  15  * can be paneled in a variety of setups such as 2x1=128x64, 4x4=256x256 and
  16  * so on. The interface between the board and the host is TTL based GPIO. The
  17  * GPIO requirements are 8 writable data lines and 4+n lines for control. On a
  18  * GPIO-less system, the board can be tested by connecting the respective sigs
  19  * up to a parallel port connector. The driver requires the IO addresses for
  20  * data and control GPIO at load time. It is unable to probe for the
  21  * existence of the LCD so it must be told at load time whether it should
  22  * be enabled or not.
  23  *
  24  * Todo:
  25  * - testing with 4x4
  26  * - testing with interrupt hw
  27  *
  28  * General notes:
  29  * - User must set tuhold. It's in microseconds. According to the 108 spec,
  30  *   the hold time is supposed to be at least 1 microsecond.
  31  * - User must set num_cols=x num_rows=y, eg: x=2 means 128
  32  * - User must set arcfb_enable=1 to enable it
  33  * - User must set dio_addr=0xIOADDR cio_addr=0xIOADDR
  34  *
  35  */
  36
  37 #include <linux/module.h>
  38 #include <linux/kernel.h>
  39 #include <linux/errno.h>
  40 #include <linux/string.h>
  41 #include <linux/mm.h>
  42 #include <linux/slab.h>
  43 #include <linux/vmalloc.h>
  44 #include <linux/delay.h>
  45 #include <linux/interrupt.h>
  46 #include <linux/fb.h>
  47 #include <linux/init.h>
  48 #include <linux/arcfb.h>
  49 #include <linux/platform_device.h>
  50
  51 #include <asm/uaccess.h>
  52
  53 #define floor8(a) (a&(~0x07))
  54 #define floorXres(a,xres) (a&(~(xres - 1)))
  55 #define iceil8(a) (((int)((a+7)/8))*8)
  56 #define ceil64(a) (a|0x3F)
  57 #define ceilXres(a,xres) (a|(xres - 1))
  58
  59 /* ks108 chipset specific defines and code */
  60
  61 #define KS_SET_DPY_START_LINE   0xC0
  62 #define KS_SET_PAGE_NUM         0xB8
  63 #define KS_SET_X                0x40
  64 #define KS_CEHI                 0x01
  65 #define KS_CELO                 0x00
  66 #define KS_SEL_CMD              0x08
  67 #define KS_SEL_DATA             0x00
  68 #define KS_DPY_ON               0x3F
  69 #define KS_DPY_OFF              0x3E
  70 #define KS_INTACK               0x40
  71 #define KS_CLRINT               0x02
  72
  73 struct arcfb_par {
  74         unsigned long dio_addr;
  75         unsigned long cio_addr;
  76         unsigned long c2io_addr;
  77         atomic_t ref_count;
  78         unsigned char cslut[9];
  79         struct fb_info *info;
  80         unsigned int irq;
  81         spinlock_t lock;
  82 };
  83
  84 static struct fb_fix_screeninfo arcfb_fix __initdata = {
  85         .id =           "arcfb",
  86         .type =         FB_TYPE_PACKED_PIXELS,
  87         .visual =       FB_VISUAL_MONO01,
  88         .xpanstep =     0,
  89         .ypanstep =     1,
  90         .ywrapstep =    0,
  91         .accel =        FB_ACCEL_NONE,
  92 };
  93
  94 static struct fb_var_screeninfo arcfb_var __initdata = {
  95         .xres           = 128,
  96         .yres           = 64,
  97         .xres_virtual   = 128,
  98         .yres_virtual   = 64,
  99         .bits_per_pixel = 1,
 100         .nonstd         = 1,
 101 };
 102
 103 static unsigned long num_cols;
 104 static unsigned long num_rows;
 105 static unsigned long dio_addr;
 106 static unsigned long cio_addr;
 107 static unsigned long c2io_addr;
 108 static unsigned long splashval;
 109 static unsigned long tuhold;
 110 static unsigned int nosplash;
 111 static unsigned int arcfb_enable;
 112 static unsigned int irq;
 113
 114 static DECLARE_WAIT_QUEUE_HEAD(arcfb_waitq);
 115
 116 static void ks108_writeb_ctl(struct arcfb_par *par,
 117                                 unsigned int chipindex, unsigned char value)
 118 {
 119         unsigned char chipselval = par->cslut[chipindex];
 120
 121         outb(chipselval|KS_CEHI|KS_SEL_CMD, par->cio_addr);
 122         outb(value, par->dio_addr);
 123         udelay(tuhold);
 124         outb(chipselval|KS_CELO|KS_SEL_CMD, par->cio_addr);
 125 }
 126
 127 static void ks108_writeb_mainctl(struct arcfb_par *par, unsigned char value)
 128 {
 129
 130         outb(value, par->cio_addr);
 131         udelay(tuhold);
 132 }
 133
 134 static unsigned char ks108_readb_ctl2(struct arcfb_par *par)
 135 {
 136         return inb(par->c2io_addr);
 137 }
 138
 139 static void ks108_writeb_data(struct arcfb_par *par,
 140                                 unsigned int chipindex, unsigned char value)
 141 {
 142         unsigned char chipselval = par->cslut[chipindex];
 143
 144         outb(chipselval|KS_CEHI|KS_SEL_DATA, par->cio_addr);
 145         outb(value, par->dio_addr);
 146         udelay(tuhold);
 147         outb(chipselval|KS_CELO|KS_SEL_DATA, par->cio_addr);
 148 }
 149
 150 static void ks108_set_start_line(struct arcfb_par *par,
 151                                 unsigned int chipindex, unsigned char y)
 152 {
 153         ks108_writeb_ctl(par, chipindex, KS_SET_DPY_START_LINE|y);
 154 }
 155
 156 static void ks108_set_yaddr(struct arcfb_par *par,
 157                                 unsigned int chipindex, unsigned char y)
 158 {
 159         ks108_writeb_ctl(par, chipindex, KS_SET_PAGE_NUM|y);
 160 }
 161
 162 static void ks108_set_xaddr(struct arcfb_par *par,
 163                                 unsigned int chipindex, unsigned char x)
 164 {
 165         ks108_writeb_ctl(par, chipindex, KS_SET_X|x);
 166 }
 167
 168 static void ks108_clear_lcd(struct arcfb_par *par, unsigned int chipindex)
 169 {
 170         int i,j;
 171
 172         for (i = 0; i <= 8; i++) {
 173                 ks108_set_yaddr(par, chipindex, i);
 174                 ks108_set_xaddr(par, chipindex, 0);
 175                 for (j = 0; j < 64; j++) {
 176                         ks108_writeb_data(par, chipindex,
 177                                 (unsigned char) splashval);
 178                 }
 179         }
 180 }
 181
 182 /* main arcfb functions */
 183
 184 static int arcfb_open(struct fb_info *info, int user)
 185 {
 186         struct arcfb_par *par = info->par;
 187
 188         atomic_inc(&par->ref_count);
 189         return 0;
 190 }
 191
 192 static int arcfb_release(struct fb_info *info, int user)
 193 {
 194         struct arcfb_par *par = info->par;
 195         int count = atomic_read(&par->ref_count);
 196
 197         if (!count)
 198                 return -EINVAL;
 199         atomic_dec(&par->ref_count);
 200         return 0;
 201 }
 202
 203 static int arcfb_pan_display(struct fb_var_screeninfo *var,
 204                                 struct fb_info *info)
 205 {
 206         int i;
 207         struct arcfb_par *par = info->par;
 208
 209         if ((var->vmode & FB_VMODE_YWRAP) && (var->yoffset < 64)
 210                 && (info->var.yres <= 64)) {
 211                 for (i = 0; i < num_cols; i++) {
 212                         ks108_set_start_line(par, i, var->yoffset);
 213                 }
 214                 info->var.yoffset = var->yoffset;
 215                 return 0;
 216         }
 217
 218         return -EINVAL;
 219 }
 220
 221 static irqreturn_t arcfb_interrupt(int vec, void *dev_instance)
 222 {
 223         struct fb_info *info = dev_instance;
 224         unsigned char ctl2status;
 225         struct arcfb_par *par = info->par;
 226
 227         ctl2status = ks108_readb_ctl2(par);
 228
 229         if (!(ctl2status & KS_INTACK)) /* not arc generated interrupt */
 230                 return IRQ_NONE;
 231
 232         ks108_writeb_mainctl(par, KS_CLRINT);
 233
 234         spin_lock(&par->lock);
 235         if (waitqueue_active(&arcfb_waitq)) {
 236                 wake_up(&arcfb_waitq);
 237         }
 238         spin_unlock(&par->lock);
 239
 240         return IRQ_HANDLED;
 241 }
 242
 243 /*
 244  * here we handle a specific page on the lcd. the complexity comes from
 245  * the fact that the fb is laidout in 8xX vertical columns. we extract
 246  * each write of 8 vertical pixels. then we shift out as we move along
 247  * X. That's what rightshift does. bitmask selects the desired input bit.
 248  */
 249 static void arcfb_lcd_update_page(struct arcfb_par *par, unsigned int upper,
 250                 unsigned int left, unsigned int right, unsigned int distance)
 251 {
 252         unsigned char *src;
 253         unsigned int xindex, yindex, chipindex, linesize;
 254         int i;
 255         unsigned char val;
 256         unsigned char bitmask, rightshift;
 257
 258         xindex = left >> 6;
 259         yindex = upper >> 6;
 260         chipindex = (xindex + (yindex*num_cols));
 261
 262         ks108_set_yaddr(par, chipindex, upper/8);
 263
 264         linesize = par->info->var.xres/8;
 265         src = par->info->screen_base + (left/8) + (upper * linesize);
 266         ks108_set_xaddr(par, chipindex, left);
 267
 268         bitmask=1;
 269         rightshift=0;
 270         while (left <= right) {
 271                 val = 0;
 272                 for (i = 0; i < 8; i++) {
 273                         if ( i > rightshift) {
 274                                 val |= (*(src + (i*linesize)) & bitmask)
 275                                                 << (i - rightshift);
 276                         } else {
 277                                 val |= (*(src + (i*linesize)) & bitmask)
 278                                                  >> (rightshift - i);
 279                         }
 280                 }
 281                 ks108_writeb_data(par, chipindex, val);
 282                 left++;
 283                 if (bitmask == 0x80) {
 284                         bitmask = 1;
 285                         src++;
 286                         rightshift=0;
 287                 } else {
 288                         bitmask <<= 1;
 289                         rightshift++;
 290                 }
 291         }
 292 }
 293
 294 /*
 295  * here we handle the entire vertical page of the update. we write across
 296  * lcd chips. update_page uses the upper/left values to decide which
 297  * chip to select for the right. upper is needed for setting the page
 298  * desired for the write.
 299  */
 300 static void arcfb_lcd_update_vert(struct arcfb_par *par, unsigned int top,
 301                 unsigned int bottom, unsigned int left, unsigned int right)
 302 {
 303         unsigned int distance, upper, lower;
 304
 305         distance = (bottom - top) + 1;
 306         upper = top;
 307         lower = top + 7;
 308
 309         while (distance > 0) {
 310                 distance -= 8;
 311                 arcfb_lcd_update_page(par, upper, left, right, 8);
 312                 upper = lower + 1;
 313                 lower = upper + 7;
 314         }
 315 }
 316
 317 /*
 318  * here we handle horizontal blocks for the update. update_vert will
 319  * handle spaning multiple pages. we break out each horizontal
 320  * block in to individual blocks no taller than 64 pixels.
 321  */
 322 static void arcfb_lcd_update_horiz(struct arcfb_par *par, unsigned int left,
 323                         unsigned int right, unsigned int top, unsigned int h)
 324 {
 325         unsigned int distance, upper, lower;
 326
 327         distance = h;
 328         upper = floor8(top);
 329         lower = min(upper + distance - 1, ceil64(upper));
 330
 331         while (distance > 0) {
 332                 distance -= ((lower - upper) + 1 );
 333                 arcfb_lcd_update_vert(par, upper, lower, left, right);
 334                 upper = lower + 1;
 335                 lower = min(upper + distance - 1, ceil64(upper));
 336         }
 337 }
 338
 339 /*
 340  * here we start the process of spliting out the fb update into
 341  * individual blocks of pixels. we end up spliting into 64x64 blocks
 342  * and finally down to 64x8 pages.
 343  */
 344 static void arcfb_lcd_update(struct arcfb_par *par, unsigned int dx,
 345                         unsigned int dy, unsigned int w, unsigned int h)
 346 {
 347         unsigned int left, right, distance, y;
 348
 349         /* align the request first */
 350         y = floor8(dy);
 351         h += dy - y;
 352         h = iceil8(h);
 353
 354         distance = w;
 355         left = dx;
 356         right = min(left + w - 1, ceil64(left));
 357
 358         while (distance > 0) {
 359                 arcfb_lcd_update_horiz(par, left, right, y, h);
 360                 distance -= ((right - left) + 1);
 361                 left = right + 1;
 362                 right = min(left + distance - 1, ceil64(left));
 363         }
 364 }
 365
 366 static void arcfb_fillrect(struct fb_info *info,
 367                            const struct fb_fillrect *rect)
 368 {
 369         struct arcfb_par *par = info->par;
 370
 371         cfb_fillrect(info, rect);
 372
 373         /* update the physical lcd */
 374         arcfb_lcd_update(par, rect->dx, rect->dy, rect->width, rect->height);
 375 }
 376
 377 static void arcfb_copyarea(struct fb_info *info,
 378                            const struct fb_copyarea *area)
 379 {
 380         struct arcfb_par *par = info->par;
 381
 382         cfb_copyarea(info, area);
 383
 384         /* update the physical lcd */
 385         arcfb_lcd_update(par, area->dx, area->dy, area->width, area->height);
 386 }
 387
 388 static void arcfb_imageblit(struct fb_info *info, const struct fb_image *image)
 389 {
 390         struct arcfb_par *par = info->par;
 391
 392         cfb_imageblit(info, image);
 393
 394         /* update the physical lcd */
 395         arcfb_lcd_update(par, image->dx, image->dy, image->width,
 396                                 image->height);
 397 }
 398
 399 static int arcfb_ioctl(struct fb_info *info,
 400                           unsigned int cmd, unsigned long arg)
 401 {
 402         void __user *argp = (void __user *)arg;
 403         struct arcfb_par *par = info->par;
 404         unsigned long flags;
 405
 406         switch (cmd) {
 407                 case FBIO_WAITEVENT:
 408                 {
 409                         DEFINE_WAIT(wait);
 410                         /* illegal to wait on arc if no irq will occur */
 411                         if (!par->irq)
 412                                 return -EINVAL;
 413
 414                         /* wait until the Arc has generated an interrupt
 415                          * which will wake us up */
 416                         spin_lock_irqsave(&par->lock, flags);
 417                         prepare_to_wait(&arcfb_waitq, &wait,
 418                                         TASK_INTERRUPTIBLE);
 419                         spin_unlock_irqrestore(&par->lock, flags);
 420                         schedule();
 421                         finish_wait(&arcfb_waitq, &wait);
 422                 }
 423                 case FBIO_GETCONTROL2:
 424                 {
 425                         unsigned char ctl2;
 426
 427                         ctl2 = ks108_readb_ctl2(info->par);
 428                         if (copy_to_user(argp, &ctl2, sizeof(ctl2)))
 429                                 return -EFAULT;
 430                         return 0;
 431                 }
 432                 default:
 433                         return -EINVAL;
 434         }
 435 }
 436
 437 /*
 438  * this is the access path from userspace. they can seek and write to
 439  * the fb. it's inefficient for them to do anything less than 64*8
 440  * writes since we update the lcd in each write() anyway.
 441  */
 442 static ssize_t arcfb_write(struct file *file, const char __user *buf, size_t count,
 443                                 loff_t *ppos)
 444 {
 445         /* modded from epson 1355 */
 446
 447         struct inode *inode;
 448         int fbidx;
 449         struct fb_info *info;
 450         unsigned long p;
 451         int err=-EINVAL;
 452         unsigned int fbmemlength,x,y,w,h, bitppos, startpos, endpos, bitcount;
 453         struct arcfb_par *par;
 454         unsigned int xres;
 455
 456         p = *ppos;
 457         inode = file->f_path.dentry->d_inode;
 458         fbidx = iminor(inode);
 459         info = registered_fb[fbidx];
 460
 461         if (!info || !info->screen_base)
 462                 return -ENODEV;
 463
 464         par = info->par;
 465         xres = info->var.xres;
 466         fbmemlength = (xres * info->var.yres)/8;
 467
 468         if (p > fbmemlength)
 469                 return -ENOSPC;
 470
 471         err = 0;
 472         if ((count + p) > fbmemlength) {
 473                 count = fbmemlength - p;
 474                 err = -ENOSPC;
 475         }
 476
 477         if (count) {
 478                 char *base_addr;
 479
 480                 base_addr = info->screen_base;
 481                 count -= copy_from_user(base_addr + p, buf, count);
 482                 *ppos += count;
 483                 err = -EFAULT;
 484         }
 485
 486
 487         bitppos = p*8;
 488         startpos = floorXres(bitppos, xres);
 489         endpos = ceilXres((bitppos + (count*8)), xres);
 490         bitcount = endpos - startpos;
 491
 492         x = startpos % xres;
 493         y = startpos / xres;
 494         w = xres;
 495         h = bitcount / xres;
 496         arcfb_lcd_update(par, x, y, w, h);
 497
 498         if (count)
 499                 return count;
 500         return err;
 501 }
 502
 503 static struct fb_ops arcfb_ops = {
 504         .owner          = THIS_MODULE,
 505         .fb_open        = arcfb_open,
 506         .fb_write       = arcfb_write,
 507         .fb_release     = arcfb_release,
 508         .fb_pan_display = arcfb_pan_display,
 509         .fb_fillrect    = arcfb_fillrect,
 510         .fb_copyarea    = arcfb_copyarea,
 511         .fb_imageblit   = arcfb_imageblit,
 512         .fb_ioctl       = arcfb_ioctl,
 513 };
 514
 515 static int __init arcfb_probe(struct platform_device *dev)
 516 {
 517         struct fb_info *info;
 518         int retval = -ENOMEM;
 519         int videomemorysize;
 520         unsigned char *videomemory;
 521         struct arcfb_par *par;
 522         int i;
 523
 524         videomemorysize = (((64*64)*num_cols)*num_rows)/8;
 525
 526         /* We need a flat backing store for the Arc's
 527            less-flat actual paged framebuffer */
 528         if (!(videomemory = vmalloc(videomemorysize)))
 529                 return retval;
 530
 531         memset(videomemory, 0, videomemorysize);
 532
 533         info = framebuffer_alloc(sizeof(struct arcfb_par), &dev->dev);
 534         if (!info)
 535                 goto err;
 536
 537         info->screen_base = (char __iomem *)videomemory;
 538         info->fbops = &arcfb_ops;
 539
 540         info->var = arcfb_var;
 541         info->fix = arcfb_fix;
 542         par = info->par;
 543         par->info = info;
 544
 545         if (!dio_addr || !cio_addr || !c2io_addr) {
 546                 printk(KERN_WARNING "no IO addresses supplied\n");
 547                 goto err1;
 548         }
 549         par->dio_addr = dio_addr;
 550         par->cio_addr = cio_addr;
 551         par->c2io_addr = c2io_addr;
 552         par->cslut[0] = 0x00;
 553         par->cslut[1] = 0x06;
 554         info->flags = FBINFO_FLAG_DEFAULT;
 555         spin_lock_init(&par->lock);
 556         retval = register_framebuffer(info);
 557         if (retval < 0)
 558                 goto err1;
 559         platform_set_drvdata(dev, info);
 560         if (irq) {
 561                 par->irq = irq;
 562                 if (request_irq(par->irq, &arcfb_interrupt, IRQF_SHARED,
 563                                 "arcfb", info)) {
 564                         printk(KERN_INFO
 565                                 "arcfb: Failed req IRQ %d\n", par->irq);
 566                         goto err1;
 567                 }
 568         }
 569         printk(KERN_INFO
 570                "fb%d: Arc frame buffer device, using %dK of video memory\n",
 571                info->node, videomemorysize >> 10);
 572
 573         /* this inits the lcd but doesn't clear dirty pixels */
 574         for (i = 0; i < num_cols * num_rows; i++) {
 575                 ks108_writeb_ctl(par, i, KS_DPY_OFF);
 576                 ks108_set_start_line(par, i, 0);
 577                 ks108_set_yaddr(par, i, 0);
 578                 ks108_set_xaddr(par, i, 0);
 579                 ks108_writeb_ctl(par, i, KS_DPY_ON);
 580         }
 581
 582         /* if we were told to splash the screen, we just clear it */
 583         if (!nosplash) {
 584                 for (i = 0; i < num_cols * num_rows; i++) {
 585                         printk(KERN_INFO "fb%d: splashing lcd %d\n",
 586                                 info->node, i);
 587                         ks108_set_start_line(par, i, 0);
 588                         ks108_clear_lcd(par, i);
 589                 }
 590         }
 591
 592         return 0;
 593 err1:
 594         framebuffer_release(info);
 595 err:
 596         vfree(videomemory);
 597         return retval;
 598 }
 599
 600 static int arcfb_remove(struct platform_device *dev)
 601 {
 602         struct fb_info *info = platform_get_drvdata(dev);
 603
 604         if (info) {
 605                 unregister_framebuffer(info);
 606                 vfree(info->screen_base);
 607                 framebuffer_release(info);
 608         }
 609         return 0;
 610 }
 611
 612 static struct platform_driver arcfb_driver = {
 613         .probe  = arcfb_probe,
 614         .remove = arcfb_remove,
 615         .driver = {
 616                 .name   = "arcfb",
 617         },
 618 };
 619
 620 static struct platform_device *arcfb_device;
 621
 622 static int __init arcfb_init(void)
 623 {
 624         int ret;
 625
 626         if (!arcfb_enable)
 627                 return -ENXIO;
 628
 629         ret = platform_driver_register(&arcfb_driver);
 630         if (!ret) {
 631                 arcfb_device = platform_device_alloc("arcfb", 0);
 632                 if (arcfb_device) {
 633                         ret = platform_device_add(arcfb_device);
 634                 } else {
 635                         ret = -ENOMEM;
 636                 }
 637                 if (ret) {
 638                         platform_device_put(arcfb_device);
 639                         platform_driver_unregister(&arcfb_driver);
 640                 }
 641         }
 642         return ret;
 643
 644 }
 645
 646 static void __exit arcfb_exit(void)
 647 {
 648         platform_device_unregister(arcfb_device);
 649         platform_driver_unregister(&arcfb_driver);
 650 }
 651
 652 module_param(num_cols, ulong, 0);
 653 MODULE_PARM_DESC(num_cols, "Num horiz panels, eg: 2 = 128 bit wide");
 654 module_param(num_rows, ulong, 0);
 655 MODULE_PARM_DESC(num_rows, "Num vert panels, eg: 1 = 64 bit high");
 656 module_param(nosplash, uint, 0);
 657 MODULE_PARM_DESC(nosplash, "Disable doing the splash screen");
 658 module_param(arcfb_enable, uint, 0);
 659 MODULE_PARM_DESC(arcfb_enable, "Enable communication with Arc board");
 660 module_param(dio_addr, ulong, 0);
 661 MODULE_PARM_DESC(dio_addr, "IO address for data, eg: 0x480");
 662 module_param(cio_addr, ulong, 0);
 663 MODULE_PARM_DESC(cio_addr, "IO address for control, eg: 0x400");
 664 module_param(c2io_addr, ulong, 0);
 665 MODULE_PARM_DESC(c2io_addr, "IO address for secondary control, eg: 0x408");
 666 module_param(splashval, ulong, 0);
 667 MODULE_PARM_DESC(splashval, "Splash pattern: 0xFF is black, 0x00 is green");
 668 module_param(tuhold, ulong, 0);
 669 MODULE_PARM_DESC(tuhold, "Time to hold between strobing data to Arc board");
 670 module_param(irq, uint, 0);
 671 MODULE_PARM_DESC(irq, "IRQ for the Arc board");
 672
 673 module_init(arcfb_init);
 674 module_exit(arcfb_exit);
 675
 676 MODULE_DESCRIPTION("fbdev driver for Arc monochrome LCD board");
 677 MODULE_AUTHOR("Jaya Kumar");
 678 MODULE_LICENSE("GPL");
 679