drivers/video/fbdev/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  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License. See the file COPYING in the main directory of this archive for
   8  * more details.
   9  *
  10  * Layout is based on skeletonfb.c by James Simmons and Geert Uytterhoeven.
  11  *
  12  * This driver was written to be used with the Arc LCD board. Arc uses a
  13  * set of KS108 chips that control individual 64x64 LCD matrices. The board
  14  * can be paneled in a variety of setups such as 2x1=128x64, 4x4=256x256 and
  15  * so on. The interface between the board and the host is TTL based GPIO. The
  16  * GPIO requirements are 8 writable data lines and 4+n lines for control. On a
  17  * GPIO-less system, the board can be tested by connecting the respective sigs
  18  * up to a parallel port connector. The driver requires the IO addresses for
  19  * data and control GPIO at load time. It is unable to probe for the
  20  * existence of the LCD so it must be told at load time whether it should
  21  * be enabled or not.
  22  *
  23  * Todo:
  24  * - testing with 4x4
  25  * - testing with interrupt hw
  26  *
  27  * General notes:
  28  * - User must set tuhold. It's in microseconds. According to the 108 spec,
  29  *   the hold time is supposed to be at least 1 microsecond.
  30  * - User must set num_cols=x num_rows=y, eg: x=2 means 128
  31  * - User must set arcfb_enable=1 to enable it
  32  * - User must set dio_addr=0xIOADDR cio_addr=0xIOADDR
  33  *
  34  */
  35
  36 #include <linux/module.h>
  37 #include <linux/kernel.h>
  38 #include <linux/errno.h>
  39 #include <linux/string.h>
  40 #include <linux/mm.h>
  41 #include <linux/vmalloc.h>
  42 #include <linux/delay.h>
  43 #include <linux/interrupt.h>
  44 #include <linux/io.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 const struct fb_fix_screeninfo arcfb_fix = {
  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 const struct fb_var_screeninfo arcfb_var = {
  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 *)par->info->screen_buffer + (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 splitting out the fb update into
 341  * individual blocks of pixels. we end up splitting 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 int arcfb_ioctl(struct fb_info *info,
 367                           unsigned int cmd, unsigned long arg)
 368 {
 369         void __user *argp = (void __user *)arg;
 370         struct arcfb_par *par = info->par;
 371         unsigned long flags;
 372
 373         switch (cmd) {
 374                 case FBIO_WAITEVENT:
 375                 {
 376                         DEFINE_WAIT(wait);
 377                         /* illegal to wait on arc if no irq will occur */
 378                         if (!par->irq)
 379                                 return -EINVAL;
 380
 381                         /* wait until the Arc has generated an interrupt
 382                          * which will wake us up */
 383                         spin_lock_irqsave(&par->lock, flags);
 384                         prepare_to_wait(&arcfb_waitq, &wait,
 385                                         TASK_INTERRUPTIBLE);
 386                         spin_unlock_irqrestore(&par->lock, flags);
 387                         schedule();
 388                         finish_wait(&arcfb_waitq, &wait);
 389                 }
 390                 fallthrough;
 391
 392                 case FBIO_GETCONTROL2:
 393                 {
 394                         unsigned char ctl2;
 395
 396                         ctl2 = ks108_readb_ctl2(info->par);
 397                         if (copy_to_user(argp, &ctl2, sizeof(ctl2)))
 398                                 return -EFAULT;
 399                         return 0;
 400                 }
 401                 default:
 402                         return -EINVAL;
 403         }
 404 }
 405
 406 static void arcfb_damage_range(struct fb_info *info, off_t off, size_t len)
 407 {
 408         struct arcfb_par *par = info->par;
 409         unsigned int xres = info->var.xres;
 410         unsigned int bitppos, startpos, endpos, bitcount;
 411         unsigned int x, y, width, height;
 412
 413         bitppos = off * 8;
 414         startpos = floorXres(bitppos, xres);
 415         endpos = ceilXres((bitppos + (len * 8)), xres);
 416         bitcount = endpos - startpos;
 417
 418         x = startpos % xres;
 419         y = startpos / xres;
 420         width = xres;
 421         height = bitcount / xres;
 422
 423         arcfb_lcd_update(par, x, y, width, height);
 424 }
 425
 426 static void arcfb_damage_area(struct fb_info *info, u32 x, u32 y,
 427                               u32 width, u32 height)
 428 {
 429         struct arcfb_par *par = info->par;
 430
 431         /* update the physical lcd */
 432         arcfb_lcd_update(par, x, y, width, height);
 433 }
 434
 435 FB_GEN_DEFAULT_DEFERRED_SYSMEM_OPS(arcfb,
 436                                    arcfb_damage_range,
 437                                    arcfb_damage_area)
 438
 439 static const struct fb_ops arcfb_ops = {
 440         .owner          = THIS_MODULE,
 441         .fb_open        = arcfb_open,
 442         __FB_DEFAULT_DEFERRED_OPS_RDWR(arcfb),
 443         .fb_release     = arcfb_release,
 444         .fb_pan_display = arcfb_pan_display,
 445         __FB_DEFAULT_DEFERRED_OPS_DRAW(arcfb),
 446         .fb_ioctl       = arcfb_ioctl,
 447         // .fb_mmap reqires deferred I/O
 448 };
 449
 450 static int arcfb_probe(struct platform_device *dev)
 451 {
 452         struct fb_info *info;
 453         int retval = -ENOMEM;
 454         int videomemorysize;
 455         unsigned char *videomemory;
 456         struct arcfb_par *par;
 457         int i;
 458
 459         videomemorysize = (((64*64)*num_cols)*num_rows)/8;
 460
 461         /* We need a flat backing store for the Arc's
 462            less-flat actual paged framebuffer */
 463         videomemory = vzalloc(videomemorysize);
 464         if (!videomemory)
 465                 return retval;
 466
 467         info = framebuffer_alloc(sizeof(struct arcfb_par), &dev->dev);
 468         if (!info)
 469                 goto err_fb_alloc;
 470
 471         info->flags |= FBINFO_VIRTFB;
 472         info->screen_buffer = videomemory;
 473         info->fbops = &arcfb_ops;
 474
 475         info->var = arcfb_var;
 476         info->fix = arcfb_fix;
 477         par = info->par;
 478         par->info = info;
 479
 480         if (!dio_addr || !cio_addr || !c2io_addr) {
 481                 printk(KERN_WARNING "no IO addresses supplied\n");
 482                 goto err_addr;
 483         }
 484         par->dio_addr = dio_addr;
 485         par->cio_addr = cio_addr;
 486         par->c2io_addr = c2io_addr;
 487         par->cslut[0] = 0x00;
 488         par->cslut[1] = 0x06;
 489         spin_lock_init(&par->lock);
 490         if (irq) {
 491                 par->irq = irq;
 492                 if (request_irq(par->irq, &arcfb_interrupt, IRQF_SHARED,
 493                                 "arcfb", info)) {
 494                         printk(KERN_INFO
 495                                 "arcfb: Failed req IRQ %d\n", par->irq);
 496                         retval = -EBUSY;
 497                         goto err_addr;
 498                 }
 499         }
 500         retval = register_framebuffer(info);
 501         if (retval < 0)
 502                 goto err_register_fb;
 503         platform_set_drvdata(dev, info);
 504         fb_info(info, "Arc frame buffer device, using %dK of video memory\n",
 505                 videomemorysize >> 10);
 506
 507         /* this inits the lcd but doesn't clear dirty pixels */
 508         for (i = 0; i < num_cols * num_rows; i++) {
 509                 ks108_writeb_ctl(par, i, KS_DPY_OFF);
 510                 ks108_set_start_line(par, i, 0);
 511                 ks108_set_yaddr(par, i, 0);
 512                 ks108_set_xaddr(par, i, 0);
 513                 ks108_writeb_ctl(par, i, KS_DPY_ON);
 514         }
 515
 516         /* if we were told to splash the screen, we just clear it */
 517         if (!nosplash) {
 518                 for (i = 0; i < num_cols * num_rows; i++) {
 519                         fb_info(info, "splashing lcd %d\n", i);
 520                         ks108_set_start_line(par, i, 0);
 521                         ks108_clear_lcd(par, i);
 522                 }
 523         }
 524
 525         return 0;
 526
 527 err_register_fb:
 528         free_irq(par->irq, info);
 529 err_addr:
 530         framebuffer_release(info);
 531 err_fb_alloc:
 532         vfree(videomemory);
 533         return retval;
 534 }
 535
 536 static void arcfb_remove(struct platform_device *dev)
 537 {
 538         struct fb_info *info = platform_get_drvdata(dev);
 539
 540         if (info) {
 541                 unregister_framebuffer(info);
 542                 if (irq)
 543                         free_irq(((struct arcfb_par *)(info->par))->irq, info);
 544                 vfree(info->screen_buffer);
 545                 framebuffer_release(info);
 546         }
 547 }
 548
 549 static struct platform_driver arcfb_driver = {
 550         .probe  = arcfb_probe,
 551         .remove = arcfb_remove,
 552         .driver = {
 553                 .name   = "arcfb",
 554         },
 555 };
 556
 557 static struct platform_device *arcfb_device;
 558
 559 static int __init arcfb_init(void)
 560 {
 561         int ret;
 562
 563         if (!arcfb_enable)
 564                 return -ENXIO;
 565
 566         ret = platform_driver_register(&arcfb_driver);
 567         if (!ret) {
 568                 arcfb_device = platform_device_alloc("arcfb", 0);
 569                 if (arcfb_device) {
 570                         ret = platform_device_add(arcfb_device);
 571                 } else {
 572                         ret = -ENOMEM;
 573                 }
 574                 if (ret) {
 575                         platform_device_put(arcfb_device);
 576                         platform_driver_unregister(&arcfb_driver);
 577                 }
 578         }
 579         return ret;
 580
 581 }
 582
 583 static void __exit arcfb_exit(void)
 584 {
 585         platform_device_unregister(arcfb_device);
 586         platform_driver_unregister(&arcfb_driver);
 587 }
 588
 589 module_param(num_cols, ulong, 0);
 590 MODULE_PARM_DESC(num_cols, "Num horiz panels, eg: 2 = 128 bit wide");
 591 module_param(num_rows, ulong, 0);
 592 MODULE_PARM_DESC(num_rows, "Num vert panels, eg: 1 = 64 bit high");
 593 module_param(nosplash, uint, 0);
 594 MODULE_PARM_DESC(nosplash, "Disable doing the splash screen");
 595 module_param(arcfb_enable, uint, 0);
 596 MODULE_PARM_DESC(arcfb_enable, "Enable communication with Arc board");
 597 module_param_hw(dio_addr, ulong, ioport, 0);
 598 MODULE_PARM_DESC(dio_addr, "IO address for data, eg: 0x480");
 599 module_param_hw(cio_addr, ulong, ioport, 0);
 600 MODULE_PARM_DESC(cio_addr, "IO address for control, eg: 0x400");
 601 module_param_hw(c2io_addr, ulong, ioport, 0);
 602 MODULE_PARM_DESC(c2io_addr, "IO address for secondary control, eg: 0x408");
 603 module_param(splashval, ulong, 0);
 604 MODULE_PARM_DESC(splashval, "Splash pattern: 0xFF is black, 0x00 is green");
 605 module_param(tuhold, ulong, 0);
 606 MODULE_PARM_DESC(tuhold, "Time to hold between strobing data to Arc board");
 607 module_param_hw(irq, uint, irq, 0);
 608 MODULE_PARM_DESC(irq, "IRQ for the Arc board");
 609
 610 module_init(arcfb_init);
 611 module_exit(arcfb_exit);
 612
 613 MODULE_DESCRIPTION("fbdev driver for Arc monochrome LCD board");
 614 MODULE_AUTHOR("Jaya Kumar");
 615 MODULE_LICENSE("GPL");
 616