drivers/video/fbdev/grvga.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Driver for Aeroflex Gaisler SVGACTRL framebuffer device.
   4  *
   5  * 2011 (c) Aeroflex Gaisler AB
   6  *
   7  * Full documentation of the core can be found here:
   8  * https://www.gaisler.com/products/grlib/grip.pdf
   9  *
  10  * Contributors: Kristoffer Glembo <kristoffer@gaisler.com>
  11  */
  12
  13 #include <linux/platform_device.h>
  14 #include <linux/dma-mapping.h>
  15 #include <linux/of.h>
  16 #include <linux/module.h>
  17 #include <linux/kernel.h>
  18 #include <linux/string.h>
  19 #include <linux/delay.h>
  20 #include <linux/errno.h>
  21 #include <linux/init.h>
  22 #include <linux/slab.h>
  23 #include <linux/tty.h>
  24 #include <linux/mm.h>
  25 #include <linux/fb.h>
  26 #include <linux/io.h>
  27
  28 struct grvga_regs {
  29         u32 status;             /* 0x00 */
  30         u32 video_length;       /* 0x04 */
  31         u32 front_porch;        /* 0x08 */
  32         u32 sync_length;        /* 0x0C */
  33         u32 line_length;        /* 0x10 */
  34         u32 fb_pos;             /* 0x14 */
  35         u32 clk_vector[4];      /* 0x18 */
  36         u32 clut;               /* 0x20 */
  37 };
  38
  39 struct grvga_par {
  40         struct grvga_regs *regs;
  41         u32 color_palette[16];  /* 16 entry pseudo palette used by fbcon in true color mode */
  42         int clk_sel;
  43         int fb_alloced;         /* = 1 if framebuffer is allocated in main memory */
  44 };
  45
  46
  47 static const struct fb_videomode grvga_modedb[] = {
  48     {
  49         /* 640x480 @ 60 Hz */
  50         NULL, 60, 640, 480, 40000, 48, 16, 39, 11, 96, 2,
  51         0, FB_VMODE_NONINTERLACED
  52     }, {
  53         /* 800x600 @ 60 Hz */
  54         NULL, 60, 800, 600, 25000, 88, 40, 23, 1, 128, 4,
  55         0, FB_VMODE_NONINTERLACED
  56     }, {
  57         /* 800x600 @ 72 Hz */
  58         NULL, 72, 800, 600, 20000, 64, 56, 23, 37, 120, 6,
  59         0, FB_VMODE_NONINTERLACED
  60     }, {
  61         /* 1024x768 @ 60 Hz */
  62         NULL, 60, 1024, 768, 15385, 160, 24, 29, 3, 136, 6,
  63         0, FB_VMODE_NONINTERLACED
  64     }
  65  };
  66
  67 static const struct fb_fix_screeninfo grvga_fix = {
  68         .id =           "AG SVGACTRL",
  69         .type =         FB_TYPE_PACKED_PIXELS,
  70         .visual =       FB_VISUAL_PSEUDOCOLOR,
  71         .xpanstep =     0,
  72         .ypanstep =     1,
  73         .ywrapstep =    0,
  74         .accel =        FB_ACCEL_NONE,
  75 };
  76
  77 static int grvga_check_var(struct fb_var_screeninfo *var,
  78                            struct fb_info *info)
  79 {
  80         struct grvga_par *par = info->par;
  81         int i;
  82
  83         if (!var->xres)
  84                 var->xres = 1;
  85         if (!var->yres)
  86                 var->yres = 1;
  87         if (var->bits_per_pixel <= 8)
  88                 var->bits_per_pixel = 8;
  89         else if (var->bits_per_pixel <= 16)
  90                 var->bits_per_pixel = 16;
  91         else if (var->bits_per_pixel <= 24)
  92                 var->bits_per_pixel = 24;
  93         else if (var->bits_per_pixel <= 32)
  94                 var->bits_per_pixel = 32;
  95         else
  96                 return -EINVAL;
  97
  98         var->xres_virtual = var->xres;
  99         var->yres_virtual = 2*var->yres;
 100
 101         if (info->fix.smem_len) {
 102                 if ((var->yres_virtual*var->xres_virtual*var->bits_per_pixel/8) > info->fix.smem_len)
 103                         return -ENOMEM;
 104         }
 105
 106         /* Which clocks that are available can be read out in these registers */
 107         for (i = 0; i <= 3 ; i++) {
 108                 if (var->pixclock == par->regs->clk_vector[i])
 109                         break;
 110         }
 111         if (i <= 3)
 112                 par->clk_sel = i;
 113         else
 114                 return -EINVAL;
 115
 116         switch (info->var.bits_per_pixel) {
 117         case 8:
 118                 var->red   = (struct fb_bitfield) {0, 8, 0};      /* offset, length, msb-right */
 119                 var->green = (struct fb_bitfield) {0, 8, 0};
 120                 var->blue  = (struct fb_bitfield) {0, 8, 0};
 121                 var->transp = (struct fb_bitfield) {0, 0, 0};
 122                 break;
 123         case 16:
 124                 var->red   = (struct fb_bitfield) {11, 5, 0};
 125                 var->green = (struct fb_bitfield) {5, 6, 0};
 126                 var->blue  = (struct fb_bitfield) {0, 5, 0};
 127                 var->transp = (struct fb_bitfield) {0, 0, 0};
 128                 break;
 129         case 24:
 130         case 32:
 131                 var->red   = (struct fb_bitfield) {16, 8, 0};
 132                 var->green = (struct fb_bitfield) {8, 8, 0};
 133                 var->blue  = (struct fb_bitfield) {0, 8, 0};
 134                 var->transp = (struct fb_bitfield) {24, 8, 0};
 135                 break;
 136         default:
 137                 return -EINVAL;
 138         }
 139
 140         return 0;
 141 }
 142
 143 static int grvga_set_par(struct fb_info *info)
 144 {
 145
 146         u32 func = 0;
 147         struct grvga_par *par = info->par;
 148
 149         __raw_writel(((info->var.yres - 1) << 16) | (info->var.xres - 1),
 150                      &par->regs->video_length);
 151
 152         __raw_writel((info->var.lower_margin << 16) | (info->var.right_margin),
 153                      &par->regs->front_porch);
 154
 155         __raw_writel((info->var.vsync_len << 16) | (info->var.hsync_len),
 156                      &par->regs->sync_length);
 157
 158         __raw_writel(((info->var.yres + info->var.lower_margin + info->var.upper_margin + info->var.vsync_len - 1) << 16) |
 159                      (info->var.xres + info->var.right_margin + info->var.left_margin + info->var.hsync_len - 1),
 160                      &par->regs->line_length);
 161
 162         switch (info->var.bits_per_pixel) {
 163         case 8:
 164                 info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
 165                 func = 1;
 166                 break;
 167         case 16:
 168                 info->fix.visual = FB_VISUAL_TRUECOLOR;
 169                 func = 2;
 170                 break;
 171         case 24:
 172         case 32:
 173                 info->fix.visual = FB_VISUAL_TRUECOLOR;
 174                 func = 3;
 175                 break;
 176         default:
 177                 return -EINVAL;
 178         }
 179
 180         __raw_writel((par->clk_sel << 6) | (func << 4) | 1,
 181                      &par->regs->status);
 182
 183         info->fix.line_length = (info->var.xres_virtual*info->var.bits_per_pixel)/8;
 184         return 0;
 185 }
 186
 187 static int grvga_setcolreg(unsigned regno, unsigned red, unsigned green, unsigned blue, unsigned transp, struct fb_info *info)
 188 {
 189         struct grvga_par *par;
 190         par = info->par;
 191
 192         if (regno >= 256)       /* Size of CLUT */
 193                 return -EINVAL;
 194
 195         if (info->var.grayscale) {
 196                 /* grayscale = 0.30*R + 0.59*G + 0.11*B */
 197                 red = green = blue = (red * 77 + green * 151 + blue * 28) >> 8;
 198         }
 199
 200
 201
 202 #define CNVT_TOHW(val, width) ((((val)<<(width))+0x7FFF-(val))>>16)
 203
 204         red    = CNVT_TOHW(red,   info->var.red.length);
 205         green  = CNVT_TOHW(green, info->var.green.length);
 206         blue   = CNVT_TOHW(blue,  info->var.blue.length);
 207         transp = CNVT_TOHW(transp, info->var.transp.length);
 208
 209 #undef CNVT_TOHW
 210
 211         /* In PSEUDOCOLOR we use the hardware CLUT */
 212         if (info->fix.visual == FB_VISUAL_PSEUDOCOLOR)
 213                 __raw_writel((regno << 24) | (red << 16) | (green << 8) | blue,
 214                              &par->regs->clut);
 215
 216         /* Truecolor uses the pseudo palette */
 217         else if (info->fix.visual == FB_VISUAL_TRUECOLOR) {
 218                 u32 v;
 219                 if (regno >= 16)
 220                         return -EINVAL;
 221
 222
 223                 v =     (red    << info->var.red.offset)   |
 224                         (green  << info->var.green.offset) |
 225                         (blue   << info->var.blue.offset)  |
 226                         (transp << info->var.transp.offset);
 227
 228                 ((u32 *) (info->pseudo_palette))[regno] = v;
 229         }
 230         return 0;
 231 }
 232
 233 static int grvga_pan_display(struct fb_var_screeninfo *var,
 234                              struct fb_info *info)
 235 {
 236         struct grvga_par *par = info->par;
 237         struct fb_fix_screeninfo *fix = &info->fix;
 238         u32 base_addr;
 239
 240         if (var->xoffset != 0)
 241                 return -EINVAL;
 242
 243         base_addr = fix->smem_start + (var->yoffset * fix->line_length);
 244         base_addr &= ~3UL;
 245
 246         /* Set framebuffer base address  */
 247         __raw_writel(base_addr,
 248                      &par->regs->fb_pos);
 249
 250         return 0;
 251 }
 252
 253 static const struct fb_ops grvga_ops = {
 254         .owner          = THIS_MODULE,
 255         FB_DEFAULT_IOMEM_OPS,
 256         .fb_check_var   = grvga_check_var,
 257         .fb_set_par     = grvga_set_par,
 258         .fb_setcolreg   = grvga_setcolreg,
 259         .fb_pan_display = grvga_pan_display,
 260 };
 261
 262 static int grvga_parse_custom(char *options,
 263                               struct fb_var_screeninfo *screendata)
 264 {
 265         char *this_opt;
 266         int count = 0;
 267         if (!options || !*options)
 268                 return -1;
 269
 270         while ((this_opt = strsep(&options, " ")) != NULL) {
 271                 if (!*this_opt)
 272                         continue;
 273
 274                 switch (count) {
 275                 case 0:
 276                         screendata->pixclock = simple_strtoul(this_opt, NULL, 0);
 277                         count++;
 278                         break;
 279                 case 1:
 280                         screendata->xres = screendata->xres_virtual = simple_strtoul(this_opt, NULL, 0);
 281                         count++;
 282                         break;
 283                 case 2:
 284                         screendata->right_margin = simple_strtoul(this_opt, NULL, 0);
 285                         count++;
 286                         break;
 287                 case 3:
 288                         screendata->hsync_len = simple_strtoul(this_opt, NULL, 0);
 289                         count++;
 290                         break;
 291                 case 4:
 292                         screendata->left_margin = simple_strtoul(this_opt, NULL, 0);
 293                         count++;
 294                         break;
 295                 case 5:
 296                         screendata->yres = screendata->yres_virtual = simple_strtoul(this_opt, NULL, 0);
 297                         count++;
 298                         break;
 299                 case 6:
 300                         screendata->lower_margin = simple_strtoul(this_opt, NULL, 0);
 301                         count++;
 302                         break;
 303                 case 7:
 304                         screendata->vsync_len = simple_strtoul(this_opt, NULL, 0);
 305                         count++;
 306                         break;
 307                 case 8:
 308                         screendata->upper_margin = simple_strtoul(this_opt, NULL, 0);
 309                         count++;
 310                         break;
 311                 case 9:
 312                         screendata->bits_per_pixel = simple_strtoul(this_opt, NULL, 0);
 313                         count++;
 314                         break;
 315                 default:
 316                         return -1;
 317                 }
 318         }
 319         screendata->activate  = FB_ACTIVATE_NOW;
 320         screendata->vmode     = FB_VMODE_NONINTERLACED;
 321         return 0;
 322 }
 323
 324 static int grvga_probe(struct platform_device *dev)
 325 {
 326         struct fb_info *info;
 327         int retval = -ENOMEM;
 328         unsigned long virtual_start;
 329         unsigned long grvga_fix_addr = 0;
 330         unsigned long physical_start = 0;
 331         unsigned long grvga_mem_size = 0;
 332         struct grvga_par *par = NULL;
 333         char *options = NULL, *mode_opt = NULL;
 334
 335         info = framebuffer_alloc(sizeof(struct grvga_par), &dev->dev);
 336         if (!info)
 337                 return -ENOMEM;
 338
 339         /* Expecting: "grvga: modestring, [addr:<framebuffer physical address>], [size:<framebuffer size>]
 340          *
 341          * If modestring is custom:<custom mode string> we parse the string which then contains all videoparameters
 342          * If address is left out, we allocate memory,
 343          * if size is left out we only allocate enough to support the given mode.
 344          */
 345         if (fb_get_options("grvga", &options)) {
 346                 retval = -ENODEV;
 347                 goto free_fb;
 348         }
 349
 350         if (!options || !*options)
 351                 options =  "640x480-8@60";
 352
 353         while (1) {
 354                 char *this_opt = strsep(&options, ",");
 355
 356                 if (!this_opt)
 357                         break;
 358
 359                 if (!strncmp(this_opt, "custom", 6)) {
 360                         if (grvga_parse_custom(this_opt, &info->var) < 0) {
 361                                 dev_err(&dev->dev, "Failed to parse custom mode (%s).\n", this_opt);
 362                                 retval = -EINVAL;
 363                                 goto free_fb;
 364                         }
 365                 } else if (!strncmp(this_opt, "addr", 4))
 366                         grvga_fix_addr = simple_strtoul(this_opt + 5, NULL, 16);
 367                 else if (!strncmp(this_opt, "size", 4))
 368                         grvga_mem_size = simple_strtoul(this_opt + 5, NULL, 0);
 369                 else
 370                         mode_opt = this_opt;
 371         }
 372
 373         par = info->par;
 374         info->fbops = &grvga_ops;
 375         info->fix = grvga_fix;
 376         info->pseudo_palette = par->color_palette;
 377         info->flags = FBINFO_PARTIAL_PAN_OK | FBINFO_HWACCEL_YPAN;
 378         info->fix.smem_len = grvga_mem_size;
 379
 380         if (!devm_request_mem_region(&dev->dev, dev->resource[0].start,
 381                     resource_size(&dev->resource[0]), "grlib-svgactrl regs")) {
 382                 dev_err(&dev->dev, "registers already mapped\n");
 383                 retval = -EBUSY;
 384                 goto free_fb;
 385         }
 386
 387         par->regs = of_ioremap(&dev->resource[0], 0,
 388                                resource_size(&dev->resource[0]),
 389                                "grlib-svgactrl regs");
 390
 391         if (!par->regs) {
 392                 dev_err(&dev->dev, "failed to map registers\n");
 393                 retval = -ENOMEM;
 394                 goto free_fb;
 395         }
 396
 397         retval = fb_alloc_cmap(&info->cmap, 256, 0);
 398         if (retval < 0) {
 399                 dev_err(&dev->dev, "failed to allocate mem with fb_alloc_cmap\n");
 400                 retval = -ENOMEM;
 401                 goto unmap_regs;
 402         }
 403
 404         if (mode_opt) {
 405                 retval = fb_find_mode(&info->var, info, mode_opt,
 406                                       grvga_modedb, sizeof(grvga_modedb), &grvga_modedb[0], 8);
 407                 if (!retval || retval == 4) {
 408                         retval = -EINVAL;
 409                         goto dealloc_cmap;
 410                 }
 411         }
 412
 413         if (!grvga_mem_size)
 414                 grvga_mem_size = info->var.xres_virtual * info->var.yres_virtual * info->var.bits_per_pixel/8;
 415
 416         if (grvga_fix_addr) {
 417                 /* Got framebuffer base address from argument list */
 418
 419                 physical_start = grvga_fix_addr;
 420
 421                 if (!devm_request_mem_region(&dev->dev, physical_start,
 422                                              grvga_mem_size, dev->name)) {
 423                         dev_err(&dev->dev, "failed to request memory region\n");
 424                         retval = -ENOMEM;
 425                         goto dealloc_cmap;
 426                 }
 427
 428                 virtual_start = (unsigned long) ioremap(physical_start, grvga_mem_size);
 429
 430                 if (!virtual_start) {
 431                         dev_err(&dev->dev, "error mapping framebuffer memory\n");
 432                         retval = -ENOMEM;
 433                         goto dealloc_cmap;
 434                 }
 435         } else {        /* Allocate frambuffer memory */
 436
 437                 unsigned long page;
 438
 439                 virtual_start = (unsigned long) __get_free_pages(GFP_DMA,
 440                                                                  get_order(grvga_mem_size));
 441                 if (!virtual_start) {
 442                         dev_err(&dev->dev,
 443                                 "unable to allocate framebuffer memory (%lu bytes)\n",
 444                                 grvga_mem_size);
 445                         retval = -ENOMEM;
 446                         goto dealloc_cmap;
 447                 }
 448
 449                 physical_start = dma_map_single(&dev->dev, (void *)virtual_start, grvga_mem_size, DMA_TO_DEVICE);
 450
 451                 /* Set page reserved so that mmap will work. This is necessary
 452                  * since we'll be remapping normal memory.
 453                  */
 454                 for (page = virtual_start;
 455                      page < PAGE_ALIGN(virtual_start + grvga_mem_size);
 456                      page += PAGE_SIZE) {
 457                         SetPageReserved(virt_to_page(page));
 458                 }
 459
 460                 par->fb_alloced = 1;
 461         }
 462
 463         memset((unsigned long *) virtual_start, 0, grvga_mem_size);
 464
 465         info->screen_base = (char __iomem *) virtual_start;
 466         info->fix.smem_start = physical_start;
 467         info->fix.smem_len   = grvga_mem_size;
 468
 469         dev_set_drvdata(&dev->dev, info);
 470
 471         dev_info(&dev->dev,
 472                  "Aeroflex Gaisler framebuffer device (fb%d), %dx%d-%d, using %luK of video memory @ %p\n",
 473                  info->node, info->var.xres, info->var.yres, info->var.bits_per_pixel,
 474                  grvga_mem_size >> 10, info->screen_base);
 475
 476         retval = register_framebuffer(info);
 477         if (retval < 0) {
 478                 dev_err(&dev->dev, "failed to register framebuffer\n");
 479                 goto free_mem;
 480         }
 481
 482         __raw_writel(physical_start, &par->regs->fb_pos);
 483         __raw_writel(__raw_readl(&par->regs->status) | 1,  /* Enable framebuffer */
 484                      &par->regs->status);
 485
 486         return 0;
 487
 488 free_mem:
 489         if (grvga_fix_addr)
 490                 iounmap((void *)virtual_start);
 491         else
 492                 kfree((void *)virtual_start);
 493 dealloc_cmap:
 494         fb_dealloc_cmap(&info->cmap);
 495 unmap_regs:
 496         of_iounmap(&dev->resource[0], par->regs,
 497                    resource_size(&dev->resource[0]));
 498 free_fb:
 499         framebuffer_release(info);
 500
 501         return retval;
 502 }
 503
 504 static void grvga_remove(struct platform_device *device)
 505 {
 506         struct fb_info *info = dev_get_drvdata(&device->dev);
 507         struct grvga_par *par;
 508
 509         if (info) {
 510                 par = info->par;
 511                 unregister_framebuffer(info);
 512                 fb_dealloc_cmap(&info->cmap);
 513
 514                 of_iounmap(&device->resource[0], par->regs,
 515                            resource_size(&device->resource[0]));
 516
 517                 if (!par->fb_alloced)
 518                         iounmap(info->screen_base);
 519                 else
 520                         kfree((void *)info->screen_base);
 521
 522                 framebuffer_release(info);
 523         }
 524 }
 525
 526 static struct of_device_id svgactrl_of_match[] = {
 527         {
 528                 .name = "GAISLER_SVGACTRL",
 529         },
 530         {
 531                 .name = "01_063",
 532         },
 533         {},
 534 };
 535 MODULE_DEVICE_TABLE(of, svgactrl_of_match);
 536
 537 static struct platform_driver grvga_driver = {
 538         .driver = {
 539                 .name = "grlib-svgactrl",
 540                 .of_match_table = svgactrl_of_match,
 541         },
 542         .probe          = grvga_probe,
 543         .remove_new     = grvga_remove,
 544 };
 545
 546 module_platform_driver(grvga_driver);
 547
 548 MODULE_LICENSE("GPL");
 549 MODULE_AUTHOR("Aeroflex Gaisler");
 550 MODULE_DESCRIPTION("Aeroflex Gaisler framebuffer device driver");