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/fb.h> 45 #include <linux/init.h> 46 #include <linux/arcfb.h> 47 #include <linux/platform_device.h> 48 49 #include <linux/uaccess.h> 50 51 #define floor8(a) (a&(~0x07)) 52 #define floorXres(a,xres) (a&(~(xres - 1))) 53 #define iceil8(a) (((int)((a+7)/8))*8) 54 #define ceil64(a) (a|0x3F) 55 #define ceilXres(a,xres) (a|(xres - 1)) 56 57 /* ks108 chipset specific defines and code */ 58 59 #define KS_SET_DPY_START_LINE 0xC0 60 #define KS_SET_PAGE_NUM 0xB8 61 #define KS_SET_X 0x40 62 #define KS_CEHI 0x01 63 #define KS_CELO 0x00 64 #define KS_SEL_CMD 0x08 65 #define KS_SEL_DATA 0x00 66 #define KS_DPY_ON 0x3F 67 #define KS_DPY_OFF 0x3E 68 #define KS_INTACK 0x40 69 #define KS_CLRINT 0x02 70 71 struct arcfb_par { 72 unsigned long dio_addr; 73 unsigned long cio_addr; 74 unsigned long c2io_addr; 75 atomic_t ref_count; 76 unsigned char cslut[9]; 77 struct fb_info *info; 78 unsigned int irq; 79 spinlock_t lock; 80 }; 81 82 static const struct fb_fix_screeninfo arcfb_fix = { 83 .id = "arcfb", 84 .type = FB_TYPE_PACKED_PIXELS, 85 .visual = FB_VISUAL_MONO01, 86 .xpanstep = 0, 87 .ypanstep = 1, 88 .ywrapstep = 0, 89 .accel = FB_ACCEL_NONE, 90 }; 91 92 static const struct fb_var_screeninfo arcfb_var = { 93 .xres = 128, 94 .yres = 64, 95 .xres_virtual = 128, 96 .yres_virtual = 64, 97 .bits_per_pixel = 1, 98 .nonstd = 1, 99 }; 100 101 static unsigned long num_cols; 102 static unsigned long num_rows; 103 static unsigned long dio_addr; 104 static unsigned long cio_addr; 105 static unsigned long c2io_addr; 106 static unsigned long splashval; 107 static unsigned long tuhold; 108 static unsigned int nosplash; 109 static unsigned int arcfb_enable; 110 static unsigned int irq; 111 112 static DECLARE_WAIT_QUEUE_HEAD(arcfb_waitq); 113 114 static void ks108_writeb_ctl(struct arcfb_par *par, 115 unsigned int chipindex, unsigned char value) 116 { 117 unsigned char chipselval = par->cslut[chipindex]; 118 119 outb(chipselval|KS_CEHI|KS_SEL_CMD, par->cio_addr); 120 outb(value, par->dio_addr); 121 udelay(tuhold); 122 outb(chipselval|KS_CELO|KS_SEL_CMD, par->cio_addr); 123 } 124 125 static void ks108_writeb_mainctl(struct arcfb_par *par, unsigned char value) 126 { 127 128 outb(value, par->cio_addr); 129 udelay(tuhold); 130 } 131 132 static unsigned char ks108_readb_ctl2(struct arcfb_par *par) 133 { 134 return inb(par->c2io_addr); 135 } 136 137 static void ks108_writeb_data(struct arcfb_par *par, 138 unsigned int chipindex, unsigned char value) 139 { 140 unsigned char chipselval = par->cslut[chipindex]; 141 142 outb(chipselval|KS_CEHI|KS_SEL_DATA, par->cio_addr); 143 outb(value, par->dio_addr); 144 udelay(tuhold); 145 outb(chipselval|KS_CELO|KS_SEL_DATA, par->cio_addr); 146 } 147 148 static void ks108_set_start_line(struct arcfb_par *par, 149 unsigned int chipindex, unsigned char y) 150 { 151 ks108_writeb_ctl(par, chipindex, KS_SET_DPY_START_LINE|y); 152 } 153 154 static void ks108_set_yaddr(struct arcfb_par *par, 155 unsigned int chipindex, unsigned char y) 156 { 157 ks108_writeb_ctl(par, chipindex, KS_SET_PAGE_NUM|y); 158 } 159 160 static void ks108_set_xaddr(struct arcfb_par *par, 161 unsigned int chipindex, unsigned char x) 162 { 163 ks108_writeb_ctl(par, chipindex, KS_SET_X|x); 164 } 165 166 static void ks108_clear_lcd(struct arcfb_par *par, unsigned int chipindex) 167 { 168 int i,j; 169 170 for (i = 0; i <= 8; i++) { 171 ks108_set_yaddr(par, chipindex, i); 172 ks108_set_xaddr(par, chipindex, 0); 173 for (j = 0; j < 64; j++) { 174 ks108_writeb_data(par, chipindex, 175 (unsigned char) splashval); 176 } 177 } 178 } 179 180 /* main arcfb functions */ 181 182 static int arcfb_open(struct fb_info *info, int user) 183 { 184 struct arcfb_par *par = info->par; 185 186 atomic_inc(&par->ref_count); 187 return 0; 188 } 189 190 static int arcfb_release(struct fb_info *info, int user) 191 { 192 struct arcfb_par *par = info->par; 193 int count = atomic_read(&par->ref_count); 194 195 if (!count) 196 return -EINVAL; 197 atomic_dec(&par->ref_count); 198 return 0; 199 } 200 201 static int arcfb_pan_display(struct fb_var_screeninfo *var, 202 struct fb_info *info) 203 { 204 int i; 205 struct arcfb_par *par = info->par; 206 207 if ((var->vmode & FB_VMODE_YWRAP) && (var->yoffset < 64) 208 && (info->var.yres <= 64)) { 209 for (i = 0; i < num_cols; i++) { 210 ks108_set_start_line(par, i, var->yoffset); 211 } 212 info->var.yoffset = var->yoffset; 213 return 0; 214 } 215 216 return -EINVAL; 217 } 218 219 static irqreturn_t arcfb_interrupt(int vec, void *dev_instance) 220 { 221 struct fb_info *info = dev_instance; 222 unsigned char ctl2status; 223 struct arcfb_par *par = info->par; 224 225 ctl2status = ks108_readb_ctl2(par); 226 227 if (!(ctl2status & KS_INTACK)) /* not arc generated interrupt */ 228 return IRQ_NONE; 229 230 ks108_writeb_mainctl(par, KS_CLRINT); 231 232 spin_lock(&par->lock); 233 if (waitqueue_active(&arcfb_waitq)) { 234 wake_up(&arcfb_waitq); 235 } 236 spin_unlock(&par->lock); 237 238 return IRQ_HANDLED; 239 } 240 241 /* 242 * here we handle a specific page on the lcd. the complexity comes from 243 * the fact that the fb is laidout in 8xX vertical columns. we extract 244 * each write of 8 vertical pixels. then we shift out as we move along 245 * X. That's what rightshift does. bitmask selects the desired input bit. 246 */ 247 static void arcfb_lcd_update_page(struct arcfb_par *par, unsigned int upper, 248 unsigned int left, unsigned int right, unsigned int distance) 249 { 250 unsigned char *src; 251 unsigned int xindex, yindex, chipindex, linesize; 252 int i; 253 unsigned char val; 254 unsigned char bitmask, rightshift; 255 256 xindex = left >> 6; 257 yindex = upper >> 6; 258 chipindex = (xindex + (yindex*num_cols)); 259 260 ks108_set_yaddr(par, chipindex, upper/8); 261 262 linesize = par->info->var.xres/8; 263 src = (unsigned char __force *) par->info->screen_base + (left/8) + 264 (upper * linesize); 265 ks108_set_xaddr(par, chipindex, left); 266 267 bitmask=1; 268 rightshift=0; 269 while (left <= right) { 270 val = 0; 271 for (i = 0; i < 8; i++) { 272 if ( i > rightshift) { 273 val |= (*(src + (i*linesize)) & bitmask) 274 << (i - rightshift); 275 } else { 276 val |= (*(src + (i*linesize)) & bitmask) 277 >> (rightshift - i); 278 } 279 } 280 ks108_writeb_data(par, chipindex, val); 281 left++; 282 if (bitmask == 0x80) { 283 bitmask = 1; 284 src++; 285 rightshift=0; 286 } else { 287 bitmask <<= 1; 288 rightshift++; 289 } 290 } 291 } 292 293 /* 294 * here we handle the entire vertical page of the update. we write across 295 * lcd chips. update_page uses the upper/left values to decide which 296 * chip to select for the right. upper is needed for setting the page 297 * desired for the write. 298 */ 299 static void arcfb_lcd_update_vert(struct arcfb_par *par, unsigned int top, 300 unsigned int bottom, unsigned int left, unsigned int right) 301 { 302 unsigned int distance, upper, lower; 303 304 distance = (bottom - top) + 1; 305 upper = top; 306 lower = top + 7; 307 308 while (distance > 0) { 309 distance -= 8; 310 arcfb_lcd_update_page(par, upper, left, right, 8); 311 upper = lower + 1; 312 lower = upper + 7; 313 } 314 } 315 316 /* 317 * here we handle horizontal blocks for the update. update_vert will 318 * handle spaning multiple pages. we break out each horizontal 319 * block in to individual blocks no taller than 64 pixels. 320 */ 321 static void arcfb_lcd_update_horiz(struct arcfb_par *par, unsigned int left, 322 unsigned int right, unsigned int top, unsigned int h) 323 { 324 unsigned int distance, upper, lower; 325 326 distance = h; 327 upper = floor8(top); 328 lower = min(upper + distance - 1, ceil64(upper)); 329 330 while (distance > 0) { 331 distance -= ((lower - upper) + 1 ); 332 arcfb_lcd_update_vert(par, upper, lower, left, right); 333 upper = lower + 1; 334 lower = min(upper + distance - 1, ceil64(upper)); 335 } 336 } 337 338 /* 339 * here we start the process of splitting out the fb update into 340 * individual blocks of pixels. we end up splitting into 64x64 blocks 341 * and finally down to 64x8 pages. 342 */ 343 static void arcfb_lcd_update(struct arcfb_par *par, unsigned int dx, 344 unsigned int dy, unsigned int w, unsigned int h) 345 { 346 unsigned int left, right, distance, y; 347 348 /* align the request first */ 349 y = floor8(dy); 350 h += dy - y; 351 h = iceil8(h); 352 353 distance = w; 354 left = dx; 355 right = min(left + w - 1, ceil64(left)); 356 357 while (distance > 0) { 358 arcfb_lcd_update_horiz(par, left, right, y, h); 359 distance -= ((right - left) + 1); 360 left = right + 1; 361 right = min(left + distance - 1, ceil64(left)); 362 } 363 } 364 365 static void arcfb_fillrect(struct fb_info *info, 366 const struct fb_fillrect *rect) 367 { 368 struct arcfb_par *par = info->par; 369 370 sys_fillrect(info, rect); 371 372 /* update the physical lcd */ 373 arcfb_lcd_update(par, rect->dx, rect->dy, rect->width, rect->height); 374 } 375 376 static void arcfb_copyarea(struct fb_info *info, 377 const struct fb_copyarea *area) 378 { 379 struct arcfb_par *par = info->par; 380 381 sys_copyarea(info, area); 382 383 /* update the physical lcd */ 384 arcfb_lcd_update(par, area->dx, area->dy, area->width, area->height); 385 } 386 387 static void arcfb_imageblit(struct fb_info *info, const struct fb_image *image) 388 { 389 struct arcfb_par *par = info->par; 390 391 sys_imageblit(info, image); 392 393 /* update the physical lcd */ 394 arcfb_lcd_update(par, image->dx, image->dy, image->width, 395 image->height); 396 } 397 398 static int arcfb_ioctl(struct fb_info *info, 399 unsigned int cmd, unsigned long arg) 400 { 401 void __user *argp = (void __user *)arg; 402 struct arcfb_par *par = info->par; 403 unsigned long flags; 404 405 switch (cmd) { 406 case FBIO_WAITEVENT: 407 { 408 DEFINE_WAIT(wait); 409 /* illegal to wait on arc if no irq will occur */ 410 if (!par->irq) 411 return -EINVAL; 412 413 /* wait until the Arc has generated an interrupt 414 * which will wake us up */ 415 spin_lock_irqsave(&par->lock, flags); 416 prepare_to_wait(&arcfb_waitq, &wait, 417 TASK_INTERRUPTIBLE); 418 spin_unlock_irqrestore(&par->lock, flags); 419 schedule(); 420 finish_wait(&arcfb_waitq, &wait); 421 } 422 fallthrough; 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 const 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 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 videomemory = vzalloc(videomemorysize); 521 if (!videomemory) 522 return retval; 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 if (irq) { 548 par->irq = irq; 549 if (request_irq(par->irq, &arcfb_interrupt, IRQF_SHARED, 550 "arcfb", info)) { 551 printk(KERN_INFO 552 "arcfb: Failed req IRQ %d\n", par->irq); 553 retval = -EBUSY; 554 goto err1; 555 } 556 } 557 retval = register_framebuffer(info); 558 if (retval < 0) 559 goto err1; 560 platform_set_drvdata(dev, info); 561 fb_info(info, "Arc frame buffer device, using %dK of video memory\n", 562 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 fb_info(info, "splashing lcd %d\n", i); 577 ks108_set_start_line(par, i, 0); 578 ks108_clear_lcd(par, i); 579 } 580 } 581 582 return 0; 583 err1: 584 framebuffer_release(info); 585 err: 586 vfree(videomemory); 587 return retval; 588 } 589 590 static int arcfb_remove(struct platform_device *dev) 591 { 592 struct fb_info *info = platform_get_drvdata(dev); 593 594 if (info) { 595 unregister_framebuffer(info); 596 if (irq) 597 free_irq(((struct arcfb_par *)(info->par))->irq, 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_hw(dio_addr, ulong, ioport, 0); 653 MODULE_PARM_DESC(dio_addr, "IO address for data, eg: 0x480"); 654 module_param_hw(cio_addr, ulong, ioport, 0); 655 MODULE_PARM_DESC(cio_addr, "IO address for control, eg: 0x400"); 656 module_param_hw(c2io_addr, ulong, ioport, 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_hw(irq, uint, irq, 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"); 671 672