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/vmalloc.h>
  43 #include <linux/delay.h>
  44 #include <linux/interrupt.h>
  45 #include <linux/fb.h>
  46 #include <linux/init.h>
  47 #include <linux/arcfb.h>
  48 #include <linux/platform_device.h>
  49
  50 #include <linux/uaccess.h>
  51
  52 #define floor8(a) (a&(~0x07))
  53 #define floorXres(a,xres) (a&(~(xres - 1)))
  54 #define iceil8(a) (((int)((a+7)/8))*8)
  55 #define ceil64(a) (a|0x3F)
  56 #define ceilXres(a,xres) (a|(xres - 1))
  57
  58 /* ks108 chipset specific defines and code */
  59
  60 #define KS_SET_DPY_START_LINE   0xC0
  61 #define KS_SET_PAGE_NUM         0xB8
  62 #define KS_SET_X                0x40
  63 #define KS_CEHI                 0x01
  64 #define KS_CELO                 0x00
  65 #define KS_SEL_CMD              0x08
  66 #define KS_SEL_DATA             0x00
  67 #define KS_DPY_ON               0x3F
  68 #define KS_DPY_OFF              0x3E
  69 #define KS_INTACK               0x40
  70 #define KS_CLRINT               0x02
  71
  72 struct arcfb_par {
  73         unsigned long dio_addr;
  74         unsigned long cio_addr;
  75         unsigned long c2io_addr;
  76         atomic_t ref_count;
  77         unsigned char cslut[9];
  78         struct fb_info *info;
  79         unsigned int irq;
  80         spinlock_t lock;
  81 };
  82
  83 static struct fb_fix_screeninfo arcfb_fix __devinitdata = {
  84         .id =           "arcfb",
  85         .type =         FB_TYPE_PACKED_PIXELS,
  86         .visual =       FB_VISUAL_MONO01,
  87         .xpanstep =     0,
  88         .ypanstep =     1,
  89         .ywrapstep =    0,
  90         .accel =        FB_ACCEL_NONE,
  91 };
  92
  93 static struct fb_var_screeninfo arcfb_var __devinitdata = {
  94         .xres           = 128,
  95         .yres           = 64,
  96         .xres_virtual   = 128,
  97         .yres_virtual   = 64,
  98         .bits_per_pixel = 1,
  99         .nonstd         = 1,
 100 };
 101
 102 static unsigned long num_cols;
 103 static unsigned long num_rows;
 104 static unsigned long dio_addr;
 105 static unsigned long cio_addr;
 106 static unsigned long c2io_addr;
 107 static unsigned long splashval;
 108 static unsigned long tuhold;
 109 static unsigned int nosplash;
 110 static unsigned int arcfb_enable;
 111 static unsigned int irq;
 112
 113 static DECLARE_WAIT_QUEUE_HEAD(arcfb_waitq);
 114
 115 static void ks108_writeb_ctl(struct arcfb_par *par,
 116                                 unsigned int chipindex, unsigned char value)
 117 {
 118         unsigned char chipselval = par->cslut[chipindex];
 119
 120         outb(chipselval|KS_CEHI|KS_SEL_CMD, par->cio_addr);
 121         outb(value, par->dio_addr);
 122         udelay(tuhold);
 123         outb(chipselval|KS_CELO|KS_SEL_CMD, par->cio_addr);
 124 }
 125
 126 static void ks108_writeb_mainctl(struct arcfb_par *par, unsigned char value)
 127 {
 128
 129         outb(value, par->cio_addr);
 130         udelay(tuhold);
 131 }
 132
 133 static unsigned char ks108_readb_ctl2(struct arcfb_par *par)
 134 {
 135         return inb(par->c2io_addr);
 136 }
 137
 138 static void ks108_writeb_data(struct arcfb_par *par,
 139                                 unsigned int chipindex, unsigned char value)
 140 {
 141         unsigned char chipselval = par->cslut[chipindex];
 142
 143         outb(chipselval|KS_CEHI|KS_SEL_DATA, par->cio_addr);
 144         outb(value, par->dio_addr);
 145         udelay(tuhold);
 146         outb(chipselval|KS_CELO|KS_SEL_DATA, par->cio_addr);
 147 }
 148
 149 static void ks108_set_start_line(struct arcfb_par *par,
 150                                 unsigned int chipindex, unsigned char y)
 151 {
 152         ks108_writeb_ctl(par, chipindex, KS_SET_DPY_START_LINE|y);
 153 }
 154
 155 static void ks108_set_yaddr(struct arcfb_par *par,
 156                                 unsigned int chipindex, unsigned char y)
 157 {
 158         ks108_writeb_ctl(par, chipindex, KS_SET_PAGE_NUM|y);
 159 }
 160
 161 static void ks108_set_xaddr(struct arcfb_par *par,
 162                                 unsigned int chipindex, unsigned char x)
 163 {
 164         ks108_writeb_ctl(par, chipindex, KS_SET_X|x);
 165 }
 166
 167 static void ks108_clear_lcd(struct arcfb_par *par, unsigned int chipindex)
 168 {
 169         int i,j;
 170
 171         for (i = 0; i <= 8; i++) {
 172                 ks108_set_yaddr(par, chipindex, i);
 173                 ks108_set_xaddr(par, chipindex, 0);
 174                 for (j = 0; j < 64; j++) {
 175                         ks108_writeb_data(par, chipindex,
 176                                 (unsigned char) splashval);
 177                 }
 178         }
 179 }
 180
 181 /* main arcfb functions */
 182
 183 static int arcfb_open(struct fb_info *info, int user)
 184 {
 185         struct arcfb_par *par = info->par;
 186
 187         atomic_inc(&par->ref_count);
 188         return 0;
 189 }
 190
 191 static int arcfb_release(struct fb_info *info, int user)
 192 {
 193         struct arcfb_par *par = info->par;
 194         int count = atomic_read(&par->ref_count);
 195
 196         if (!count)
 197                 return -EINVAL;
 198         atomic_dec(&par->ref_count);
 199         return 0;
 200 }
 201
 202 static int arcfb_pan_display(struct fb_var_screeninfo *var,
 203                                 struct fb_info *info)
 204 {
 205         int i;
 206         struct arcfb_par *par = info->par;
 207
 208         if ((var->vmode & FB_VMODE_YWRAP) && (var->yoffset < 64)
 209                 && (info->var.yres <= 64)) {
 210                 for (i = 0; i < num_cols; i++) {
 211                         ks108_set_start_line(par, i, var->yoffset);
 212                 }
 213                 info->var.yoffset = var->yoffset;
 214                 return 0;
 215         }
 216
 217         return -EINVAL;
 218 }
 219
 220 static irqreturn_t arcfb_interrupt(int vec, void *dev_instance)
 221 {
 222         struct fb_info *info = dev_instance;
 223         unsigned char ctl2status;
 224         struct arcfb_par *par = info->par;
 225
 226         ctl2status = ks108_readb_ctl2(par);
 227
 228         if (!(ctl2status & KS_INTACK)) /* not arc generated interrupt */
 229                 return IRQ_NONE;
 230
 231         ks108_writeb_mainctl(par, KS_CLRINT);
 232
 233         spin_lock(&par->lock);
 234         if (waitqueue_active(&arcfb_waitq)) {
 235                 wake_up(&arcfb_waitq);
 236         }
 237         spin_unlock(&par->lock);
 238
 239         return IRQ_HANDLED;
 240 }
 241
 242 /*
 243  * here we handle a specific page on the lcd. the complexity comes from
 244  * the fact that the fb is laidout in 8xX vertical columns. we extract
 245  * each write of 8 vertical pixels. then we shift out as we move along
 246  * X. That's what rightshift does. bitmask selects the desired input bit.
 247  */
 248 static void arcfb_lcd_update_page(struct arcfb_par *par, unsigned int upper,
 249                 unsigned int left, unsigned int right, unsigned int distance)
 250 {
 251         unsigned char *src;
 252         unsigned int xindex, yindex, chipindex, linesize;
 253         int i;
 254         unsigned char val;
 255         unsigned char bitmask, rightshift;
 256
 257         xindex = left >> 6;
 258         yindex = upper >> 6;
 259         chipindex = (xindex + (yindex*num_cols));
 260
 261         ks108_set_yaddr(par, chipindex, upper/8);
 262
 263         linesize = par->info->var.xres/8;
 264         src = (unsigned char __force *) par->info->screen_base + (left/8) +
 265                 (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         sys_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         sys_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         sys_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 fb_info *info, const char __user *buf,
 443                            size_t count, loff_t *ppos)
 444 {
 445         /* modded from epson 1355 */
 446
 447         unsigned long p;
 448         int err=-EINVAL;
 449         unsigned int fbmemlength,x,y,w,h, bitppos, startpos, endpos, bitcount;
 450         struct arcfb_par *par;
 451         unsigned int xres;
 452
 453         p = *ppos;
 454         par = info->par;
 455         xres = info->var.xres;
 456         fbmemlength = (xres * info->var.yres)/8;
 457
 458         if (p > fbmemlength)
 459                 return -ENOSPC;
 460
 461         err = 0;
 462         if ((count + p) > fbmemlength) {
 463                 count = fbmemlength - p;
 464                 err = -ENOSPC;
 465         }
 466
 467         if (count) {
 468                 char *base_addr;
 469
 470                 base_addr = (char __force *)info->screen_base;
 471                 count -= copy_from_user(base_addr + p, buf, count);
 472                 *ppos += count;
 473                 err = -EFAULT;
 474         }
 475
 476
 477         bitppos = p*8;
 478         startpos = floorXres(bitppos, xres);
 479         endpos = ceilXres((bitppos + (count*8)), xres);
 480         bitcount = endpos - startpos;
 481
 482         x = startpos % xres;
 483         y = startpos / xres;
 484         w = xres;
 485         h = bitcount / xres;
 486         arcfb_lcd_update(par, x, y, w, h);
 487
 488         if (count)
 489                 return count;
 490         return err;
 491 }
 492
 493 static struct fb_ops arcfb_ops = {
 494         .owner          = THIS_MODULE,
 495         .fb_open        = arcfb_open,
 496         .fb_read        = fb_sys_read,
 497         .fb_write       = arcfb_write,
 498         .fb_release     = arcfb_release,
 499         .fb_pan_display = arcfb_pan_display,
 500         .fb_fillrect    = arcfb_fillrect,
 501         .fb_copyarea    = arcfb_copyarea,
 502         .fb_imageblit   = arcfb_imageblit,
 503         .fb_ioctl       = arcfb_ioctl,
 504 };
 505
 506 static int __devinit arcfb_probe(struct platform_device *dev)
 507 {
 508         struct fb_info *info;
 509         int retval = -ENOMEM;
 510         int videomemorysize;
 511         unsigned char *videomemory;
 512         struct arcfb_par *par;
 513         int i;
 514
 515         videomemorysize = (((64*64)*num_cols)*num_rows)/8;
 516
 517         /* We need a flat backing store for the Arc's
 518            less-flat actual paged framebuffer */
 519         if (!(videomemory = vmalloc(videomemorysize)))
 520                 return retval;
 521
 522         memset(videomemory, 0, videomemorysize);
 523
 524         info = framebuffer_alloc(sizeof(struct arcfb_par), &dev->dev);
 525         if (!info)
 526                 goto err;
 527
 528         info->screen_base = (char __iomem *)videomemory;
 529         info->fbops = &arcfb_ops;
 530
 531         info->var = arcfb_var;
 532         info->fix = arcfb_fix;
 533         par = info->par;
 534         par->info = info;
 535
 536         if (!dio_addr || !cio_addr || !c2io_addr) {
 537                 printk(KERN_WARNING "no IO addresses supplied\n");
 538                 goto err1;
 539         }
 540         par->dio_addr = dio_addr;
 541         par->cio_addr = cio_addr;
 542         par->c2io_addr = c2io_addr;
 543         par->cslut[0] = 0x00;
 544         par->cslut[1] = 0x06;
 545         info->flags = FBINFO_FLAG_DEFAULT;
 546         spin_lock_init(&par->lock);
 547         retval = register_framebuffer(info);
 548         if (retval < 0)
 549                 goto err1;
 550         platform_set_drvdata(dev, info);
 551         if (irq) {
 552                 par->irq = irq;
 553                 if (request_irq(par->irq, &arcfb_interrupt, IRQF_SHARED,
 554                                 "arcfb", info)) {
 555                         printk(KERN_INFO
 556                                 "arcfb: Failed req IRQ %d\n", par->irq);
 557                         goto err1;
 558                 }
 559         }
 560         printk(KERN_INFO
 561                "fb%d: Arc frame buffer device, using %dK of video memory\n",
 562                info->node, videomemorysize >> 10);
 563
 564         /* this inits the lcd but doesn't clear dirty pixels */
 565         for (i = 0; i < num_cols * num_rows; i++) {
 566                 ks108_writeb_ctl(par, i, KS_DPY_OFF);
 567                 ks108_set_start_line(par, i, 0);
 568                 ks108_set_yaddr(par, i, 0);
 569                 ks108_set_xaddr(par, i, 0);
 570                 ks108_writeb_ctl(par, i, KS_DPY_ON);
 571         }
 572
 573         /* if we were told to splash the screen, we just clear it */
 574         if (!nosplash) {
 575                 for (i = 0; i < num_cols * num_rows; i++) {
 576                         printk(KERN_INFO "fb%d: splashing lcd %d\n",
 577                                 info->node, i);
 578                         ks108_set_start_line(par, i, 0);
 579                         ks108_clear_lcd(par, i);
 580                 }
 581         }
 582
 583         return 0;
 584 err1:
 585         framebuffer_release(info);
 586 err:
 587         vfree(videomemory);
 588         return retval;
 589 }
 590
 591 static int __devexit arcfb_remove(struct platform_device *dev)
 592 {
 593         struct fb_info *info = platform_get_drvdata(dev);
 594
 595         if (info) {
 596                 unregister_framebuffer(info);
 597                 vfree((void __force *)info->screen_base);
 598                 framebuffer_release(info);
 599         }
 600         return 0;
 601 }
 602
 603 static struct platform_driver arcfb_driver = {
 604         .probe  = arcfb_probe,
 605         .remove = __devexit_p(arcfb_remove),
 606         .driver = {
 607                 .name   = "arcfb",
 608         },
 609 };
 610
 611 static struct platform_device *arcfb_device;
 612
 613 static int __init arcfb_init(void)
 614 {
 615         int ret;
 616
 617         if (!arcfb_enable)
 618                 return -ENXIO;
 619
 620         ret = platform_driver_register(&arcfb_driver);
 621         if (!ret) {
 622                 arcfb_device = platform_device_alloc("arcfb", 0);
 623                 if (arcfb_device) {
 624                         ret = platform_device_add(arcfb_device);
 625                 } else {
 626                         ret = -ENOMEM;
 627                 }
 628                 if (ret) {
 629                         platform_device_put(arcfb_device);
 630                         platform_driver_unregister(&arcfb_driver);
 631                 }
 632         }
 633         return ret;
 634
 635 }
 636
 637 static void __exit arcfb_exit(void)
 638 {
 639         platform_device_unregister(arcfb_device);
 640         platform_driver_unregister(&arcfb_driver);
 641 }
 642
 643 module_param(num_cols, ulong, 0);
 644 MODULE_PARM_DESC(num_cols, "Num horiz panels, eg: 2 = 128 bit wide");
 645 module_param(num_rows, ulong, 0);
 646 MODULE_PARM_DESC(num_rows, "Num vert panels, eg: 1 = 64 bit high");
 647 module_param(nosplash, uint, 0);
 648 MODULE_PARM_DESC(nosplash, "Disable doing the splash screen");
 649 module_param(arcfb_enable, uint, 0);
 650 MODULE_PARM_DESC(arcfb_enable, "Enable communication with Arc board");
 651 module_param(dio_addr, ulong, 0);
 652 MODULE_PARM_DESC(dio_addr, "IO address for data, eg: 0x480");
 653 module_param(cio_addr, ulong, 0);
 654 MODULE_PARM_DESC(cio_addr, "IO address for control, eg: 0x400");
 655 module_param(c2io_addr, ulong, 0);
 656 MODULE_PARM_DESC(c2io_addr, "IO address for secondary control, eg: 0x408");
 657 module_param(splashval, ulong, 0);
 658 MODULE_PARM_DESC(splashval, "Splash pattern: 0xFF is black, 0x00 is green");
 659 module_param(tuhold, ulong, 0);
 660 MODULE_PARM_DESC(tuhold, "Time to hold between strobing data to Arc board");
 661 module_param(irq, uint, 0);
 662 MODULE_PARM_DESC(irq, "IRQ for the Arc board");
 663
 664 module_init(arcfb_init);
 665 module_exit(arcfb_exit);
 666
 667 MODULE_DESCRIPTION("fbdev driver for Arc monochrome LCD board");
 668 MODULE_AUTHOR("Jaya Kumar");
 669 MODULE_LICENSE("GPL");
 670