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 <linux/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 = (unsigned char __force *) par->info->screen_base + (left/8) +
 266                 (upper * linesize);
 267         ks108_set_xaddr(par, chipindex, left);
 268
 269         bitmask=1;
 270         rightshift=0;
 271         while (left <= right) {
 272                 val = 0;
 273                 for (i = 0; i < 8; i++) {
 274                         if ( i > rightshift) {
 275                                 val |= (*(src + (i*linesize)) & bitmask)
 276                                                 << (i - rightshift);
 277                         } else {
 278                                 val |= (*(src + (i*linesize)) & bitmask)
 279                                                  >> (rightshift - i);
 280                         }
 281                 }
 282                 ks108_writeb_data(par, chipindex, val);
 283                 left++;
 284                 if (bitmask == 0x80) {
 285                         bitmask = 1;
 286                         src++;
 287                         rightshift=0;
 288                 } else {
 289                         bitmask <<= 1;
 290                         rightshift++;
 291                 }
 292         }
 293 }
 294
 295 /*
 296  * here we handle the entire vertical page of the update. we write across
 297  * lcd chips. update_page uses the upper/left values to decide which
 298  * chip to select for the right. upper is needed for setting the page
 299  * desired for the write.
 300  */
 301 static void arcfb_lcd_update_vert(struct arcfb_par *par, unsigned int top,
 302                 unsigned int bottom, unsigned int left, unsigned int right)
 303 {
 304         unsigned int distance, upper, lower;
 305
 306         distance = (bottom - top) + 1;
 307         upper = top;
 308         lower = top + 7;
 309
 310         while (distance > 0) {
 311                 distance -= 8;
 312                 arcfb_lcd_update_page(par, upper, left, right, 8);
 313                 upper = lower + 1;
 314                 lower = upper + 7;
 315         }
 316 }
 317
 318 /*
 319  * here we handle horizontal blocks for the update. update_vert will
 320  * handle spaning multiple pages. we break out each horizontal
 321  * block in to individual blocks no taller than 64 pixels.
 322  */
 323 static void arcfb_lcd_update_horiz(struct arcfb_par *par, unsigned int left,
 324                         unsigned int right, unsigned int top, unsigned int h)
 325 {
 326         unsigned int distance, upper, lower;
 327
 328         distance = h;
 329         upper = floor8(top);
 330         lower = min(upper + distance - 1, ceil64(upper));
 331
 332         while (distance > 0) {
 333                 distance -= ((lower - upper) + 1 );
 334                 arcfb_lcd_update_vert(par, upper, lower, left, right);
 335                 upper = lower + 1;
 336                 lower = min(upper + distance - 1, ceil64(upper));
 337         }
 338 }
 339
 340 /*
 341  * here we start the process of spliting out the fb update into
 342  * individual blocks of pixels. we end up spliting into 64x64 blocks
 343  * and finally down to 64x8 pages.
 344  */
 345 static void arcfb_lcd_update(struct arcfb_par *par, unsigned int dx,
 346                         unsigned int dy, unsigned int w, unsigned int h)
 347 {
 348         unsigned int left, right, distance, y;
 349
 350         /* align the request first */
 351         y = floor8(dy);
 352         h += dy - y;
 353         h = iceil8(h);
 354
 355         distance = w;
 356         left = dx;
 357         right = min(left + w - 1, ceil64(left));
 358
 359         while (distance > 0) {
 360                 arcfb_lcd_update_horiz(par, left, right, y, h);
 361                 distance -= ((right - left) + 1);
 362                 left = right + 1;
 363                 right = min(left + distance - 1, ceil64(left));
 364         }
 365 }
 366
 367 static void arcfb_fillrect(struct fb_info *info,
 368                            const struct fb_fillrect *rect)
 369 {
 370         struct arcfb_par *par = info->par;
 371
 372         sys_fillrect(info, rect);
 373
 374         /* update the physical lcd */
 375         arcfb_lcd_update(par, rect->dx, rect->dy, rect->width, rect->height);
 376 }
 377
 378 static void arcfb_copyarea(struct fb_info *info,
 379                            const struct fb_copyarea *area)
 380 {
 381         struct arcfb_par *par = info->par;
 382
 383         sys_copyarea(info, area);
 384
 385         /* update the physical lcd */
 386         arcfb_lcd_update(par, area->dx, area->dy, area->width, area->height);
 387 }
 388
 389 static void arcfb_imageblit(struct fb_info *info, const struct fb_image *image)
 390 {
 391         struct arcfb_par *par = info->par;
 392
 393         sys_imageblit(info, image);
 394
 395         /* update the physical lcd */
 396         arcfb_lcd_update(par, image->dx, image->dy, image->width,
 397                                 image->height);
 398 }
 399
 400 static int arcfb_ioctl(struct fb_info *info,
 401                           unsigned int cmd, unsigned long arg)
 402 {
 403         void __user *argp = (void __user *)arg;
 404         struct arcfb_par *par = info->par;
 405         unsigned long flags;
 406
 407         switch (cmd) {
 408                 case FBIO_WAITEVENT:
 409                 {
 410                         DEFINE_WAIT(wait);
 411                         /* illegal to wait on arc if no irq will occur */
 412                         if (!par->irq)
 413                                 return -EINVAL;
 414
 415                         /* wait until the Arc has generated an interrupt
 416                          * which will wake us up */
 417                         spin_lock_irqsave(&par->lock, flags);
 418                         prepare_to_wait(&arcfb_waitq, &wait,
 419                                         TASK_INTERRUPTIBLE);
 420                         spin_unlock_irqrestore(&par->lock, flags);
 421                         schedule();
 422                         finish_wait(&arcfb_waitq, &wait);
 423                 }
 424                 case FBIO_GETCONTROL2:
 425                 {
 426                         unsigned char ctl2;
 427
 428                         ctl2 = ks108_readb_ctl2(info->par);
 429                         if (copy_to_user(argp, &ctl2, sizeof(ctl2)))
 430                                 return -EFAULT;
 431                         return 0;
 432                 }
 433                 default:
 434                         return -EINVAL;
 435         }
 436 }
 437
 438 /*
 439  * this is the access path from userspace. they can seek and write to
 440  * the fb. it's inefficient for them to do anything less than 64*8
 441  * writes since we update the lcd in each write() anyway.
 442  */
 443 static ssize_t arcfb_write(struct fb_info *info, const char __user *buf,
 444                            size_t count, loff_t *ppos)
 445 {
 446         /* modded from epson 1355 */
 447
 448         unsigned long p;
 449         int err=-EINVAL;
 450         unsigned int fbmemlength,x,y,w,h, bitppos, startpos, endpos, bitcount;
 451         struct arcfb_par *par;
 452         unsigned int xres;
 453
 454         p = *ppos;
 455         par = info->par;
 456         xres = info->var.xres;
 457         fbmemlength = (xres * info->var.yres)/8;
 458
 459         if (p > fbmemlength)
 460                 return -ENOSPC;
 461
 462         err = 0;
 463         if ((count + p) > fbmemlength) {
 464                 count = fbmemlength - p;
 465                 err = -ENOSPC;
 466         }
 467
 468         if (count) {
 469                 char *base_addr;
 470
 471                 base_addr = (char __force *)info->screen_base;
 472                 count -= copy_from_user(base_addr + p, buf, count);
 473                 *ppos += count;
 474                 err = -EFAULT;
 475         }
 476
 477
 478         bitppos = p*8;
 479         startpos = floorXres(bitppos, xres);
 480         endpos = ceilXres((bitppos + (count*8)), xres);
 481         bitcount = endpos - startpos;
 482
 483         x = startpos % xres;
 484         y = startpos / xres;
 485         w = xres;
 486         h = bitcount / xres;
 487         arcfb_lcd_update(par, x, y, w, h);
 488
 489         if (count)
 490                 return count;
 491         return err;
 492 }
 493
 494 static struct fb_ops arcfb_ops = {
 495         .owner          = THIS_MODULE,
 496         .fb_open        = arcfb_open,
 497         .fb_read        = fb_sys_read,
 498         .fb_write       = arcfb_write,
 499         .fb_release     = arcfb_release,
 500         .fb_pan_display = arcfb_pan_display,
 501         .fb_fillrect    = arcfb_fillrect,
 502         .fb_copyarea    = arcfb_copyarea,
 503         .fb_imageblit   = arcfb_imageblit,
 504         .fb_ioctl       = arcfb_ioctl,
 505 };
 506
 507 static int __init arcfb_probe(struct platform_device *dev)
 508 {
 509         struct fb_info *info;
 510         int retval = -ENOMEM;
 511         int videomemorysize;
 512         unsigned char *videomemory;
 513         struct arcfb_par *par;
 514         int i;
 515
 516         videomemorysize = (((64*64)*num_cols)*num_rows)/8;
 517
 518         /* We need a flat backing store for the Arc's
 519            less-flat actual paged framebuffer */
 520         if (!(videomemory = vmalloc(videomemorysize)))
 521                 return retval;
 522
 523         memset(videomemory, 0, videomemorysize);
 524
 525         info = framebuffer_alloc(sizeof(struct arcfb_par), &dev->dev);
 526         if (!info)
 527                 goto err;
 528
 529         info->screen_base = (char __iomem *)videomemory;
 530         info->fbops = &arcfb_ops;
 531
 532         info->var = arcfb_var;
 533         info->fix = arcfb_fix;
 534         par = info->par;
 535         par->info = info;
 536
 537         if (!dio_addr || !cio_addr || !c2io_addr) {
 538                 printk(KERN_WARNING "no IO addresses supplied\n");
 539                 goto err1;
 540         }
 541         par->dio_addr = dio_addr;
 542         par->cio_addr = cio_addr;
 543         par->c2io_addr = c2io_addr;
 544         par->cslut[0] = 0x00;
 545         par->cslut[1] = 0x06;
 546         info->flags = FBINFO_FLAG_DEFAULT;
 547         spin_lock_init(&par->lock);
 548         retval = register_framebuffer(info);
 549         if (retval < 0)
 550                 goto err1;
 551         platform_set_drvdata(dev, info);
 552         if (irq) {
 553                 par->irq = irq;
 554                 if (request_irq(par->irq, &arcfb_interrupt, IRQF_SHARED,
 555                                 "arcfb", info)) {
 556                         printk(KERN_INFO
 557                                 "arcfb: Failed req IRQ %d\n", par->irq);
 558                         goto err1;
 559                 }
 560         }
 561         printk(KERN_INFO
 562                "fb%d: Arc frame buffer device, using %dK of video memory\n",
 563                info->node, videomemorysize >> 10);
 564
 565         /* this inits the lcd but doesn't clear dirty pixels */
 566         for (i = 0; i < num_cols * num_rows; i++) {
 567                 ks108_writeb_ctl(par, i, KS_DPY_OFF);
 568                 ks108_set_start_line(par, i, 0);
 569                 ks108_set_yaddr(par, i, 0);
 570                 ks108_set_xaddr(par, i, 0);
 571                 ks108_writeb_ctl(par, i, KS_DPY_ON);
 572         }
 573
 574         /* if we were told to splash the screen, we just clear it */
 575         if (!nosplash) {
 576                 for (i = 0; i < num_cols * num_rows; i++) {
 577                         printk(KERN_INFO "fb%d: splashing lcd %d\n",
 578                                 info->node, i);
 579                         ks108_set_start_line(par, i, 0);
 580                         ks108_clear_lcd(par, i);
 581                 }
 582         }
 583
 584         return 0;
 585 err1:
 586         framebuffer_release(info);
 587 err:
 588         vfree(videomemory);
 589         return retval;
 590 }
 591
 592 static int arcfb_remove(struct platform_device *dev)
 593 {
 594         struct fb_info *info = platform_get_drvdata(dev);
 595
 596         if (info) {
 597                 unregister_framebuffer(info);
 598                 vfree((void __force *)info->screen_base);
 599                 framebuffer_release(info);
 600         }
 601         return 0;
 602 }
 603
 604 static struct platform_driver arcfb_driver = {
 605         .probe  = arcfb_probe,
 606         .remove = arcfb_remove,
 607         .driver = {
 608                 .name   = "arcfb",
 609         },
 610 };
 611
 612 static struct platform_device *arcfb_device;
 613
 614 static int __init arcfb_init(void)
 615 {
 616         int ret;
 617
 618         if (!arcfb_enable)
 619                 return -ENXIO;
 620
 621         ret = platform_driver_register(&arcfb_driver);
 622         if (!ret) {
 623                 arcfb_device = platform_device_alloc("arcfb", 0);
 624                 if (arcfb_device) {
 625                         ret = platform_device_add(arcfb_device);
 626                 } else {
 627                         ret = -ENOMEM;
 628                 }
 629                 if (ret) {
 630                         platform_device_put(arcfb_device);
 631                         platform_driver_unregister(&arcfb_driver);
 632                 }
 633         }
 634         return ret;
 635
 636 }
 637
 638 static void __exit arcfb_exit(void)
 639 {
 640         platform_device_unregister(arcfb_device);
 641         platform_driver_unregister(&arcfb_driver);
 642 }
 643
 644 module_param(num_cols, ulong, 0);
 645 MODULE_PARM_DESC(num_cols, "Num horiz panels, eg: 2 = 128 bit wide");
 646 module_param(num_rows, ulong, 0);
 647 MODULE_PARM_DESC(num_rows, "Num vert panels, eg: 1 = 64 bit high");
 648 module_param(nosplash, uint, 0);
 649 MODULE_PARM_DESC(nosplash, "Disable doing the splash screen");
 650 module_param(arcfb_enable, uint, 0);
 651 MODULE_PARM_DESC(arcfb_enable, "Enable communication with Arc board");
 652 module_param(dio_addr, ulong, 0);
 653 MODULE_PARM_DESC(dio_addr, "IO address for data, eg: 0x480");
 654 module_param(cio_addr, ulong, 0);
 655 MODULE_PARM_DESC(cio_addr, "IO address for control, eg: 0x400");
 656 module_param(c2io_addr, ulong, 0);
 657 MODULE_PARM_DESC(c2io_addr, "IO address for secondary control, eg: 0x408");
 658 module_param(splashval, ulong, 0);
 659 MODULE_PARM_DESC(splashval, "Splash pattern: 0xFF is black, 0x00 is green");
 660 module_param(tuhold, ulong, 0);
 661 MODULE_PARM_DESC(tuhold, "Time to hold between strobing data to Arc board");
 662 module_param(irq, uint, 0);
 663 MODULE_PARM_DESC(irq, "IRQ for the Arc board");
 664
 665 module_init(arcfb_init);
 666 module_exit(arcfb_exit);
 667
 668 MODULE_DESCRIPTION("fbdev driver for Arc monochrome LCD board");
 669 MODULE_AUTHOR("Jaya Kumar");
 670 MODULE_LICENSE("GPL");
 671