linux/drivers/video/grvga.c
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   1/*
   2 * Driver for Aeroflex Gaisler SVGACTRL framebuffer device.
   3 *
   4 * 2011 (c) Aeroflex Gaisler AB
   5 *
   6 * Full documentation of the core can be found here:
   7 * http://www.gaisler.com/products/grlib/grip.pdf
   8 *
   9 * This program is free software; you can redistribute it and/or modify it
  10 * under the terms of the GNU General Public License as published by the
  11 * Free Software Foundation; either version 2 of the License, or (at your
  12 * option) any later version.
  13 *
  14 * Contributors: Kristoffer Glembo <kristoffer@gaisler.com>
  15 *
  16 */
  17
  18#include <linux/platform_device.h>
  19#include <linux/dma-mapping.h>
  20#include <linux/of_platform.h>
  21#include <linux/of_device.h>
  22#include <linux/module.h>
  23#include <linux/kernel.h>
  24#include <linux/string.h>
  25#include <linux/delay.h>
  26#include <linux/errno.h>
  27#include <linux/init.h>
  28#include <linux/slab.h>
  29#include <linux/tty.h>
  30#include <linux/mm.h>
  31#include <linux/fb.h>
  32#include <linux/io.h>
  33
  34struct grvga_regs {
  35        u32 status;             /* 0x00 */
  36        u32 video_length;       /* 0x04 */
  37        u32 front_porch;        /* 0x08 */
  38        u32 sync_length;        /* 0x0C */
  39        u32 line_length;        /* 0x10 */
  40        u32 fb_pos;             /* 0x14 */
  41        u32 clk_vector[4];      /* 0x18 */
  42        u32 clut;               /* 0x20 */
  43};
  44
  45struct grvga_par {
  46        struct grvga_regs *regs;
  47        u32 color_palette[16];  /* 16 entry pseudo palette used by fbcon in true color mode */
  48        int clk_sel;
  49        int fb_alloced;         /* = 1 if framebuffer is allocated in main memory */
  50};
  51
  52
  53static const struct fb_videomode grvga_modedb[] = {
  54    {
  55        /* 640x480 @ 60 Hz */
  56        NULL, 60, 640, 480, 40000, 48, 16, 39, 11, 96, 2,
  57        0, FB_VMODE_NONINTERLACED
  58    }, {
  59        /* 800x600 @ 60 Hz */
  60        NULL, 60, 800, 600, 25000, 88, 40, 23, 1, 128, 4,
  61        0, FB_VMODE_NONINTERLACED
  62    }, {
  63        /* 800x600 @ 72 Hz */
  64        NULL, 72, 800, 600, 20000, 64, 56, 23, 37, 120, 6,
  65        0, FB_VMODE_NONINTERLACED
  66    }, {
  67        /* 1024x768 @ 60 Hz */
  68        NULL, 60, 1024, 768, 15385, 160, 24, 29, 3, 136, 6,
  69        0, FB_VMODE_NONINTERLACED
  70    }
  71 };
  72
  73static struct fb_fix_screeninfo grvga_fix = {
  74        .id =           "AG SVGACTRL",
  75        .type =         FB_TYPE_PACKED_PIXELS,
  76        .visual =       FB_VISUAL_PSEUDOCOLOR,
  77        .xpanstep =     0,
  78        .ypanstep =     1,
  79        .ywrapstep =    0,
  80        .accel =        FB_ACCEL_NONE,
  81};
  82
  83static int grvga_check_var(struct fb_var_screeninfo *var,
  84                           struct fb_info *info)
  85{
  86        struct grvga_par *par = info->par;
  87        int i;
  88
  89        if (!var->xres)
  90                var->xres = 1;
  91        if (!var->yres)
  92                var->yres = 1;
  93        if (var->bits_per_pixel <= 8)
  94                var->bits_per_pixel = 8;
  95        else if (var->bits_per_pixel <= 16)
  96                var->bits_per_pixel = 16;
  97        else if (var->bits_per_pixel <= 24)
  98                var->bits_per_pixel = 24;
  99        else if (var->bits_per_pixel <= 32)
 100                var->bits_per_pixel = 32;
 101        else
 102                return -EINVAL;
 103
 104        var->xres_virtual = var->xres;
 105        var->yres_virtual = 2*var->yres;
 106
 107        if (info->fix.smem_len) {
 108                if ((var->yres_virtual*var->xres_virtual*var->bits_per_pixel/8) > info->fix.smem_len)
 109                        return -ENOMEM;
 110        }
 111
 112        /* Which clocks that are available can be read out in these registers */
 113        for (i = 0; i <= 3 ; i++) {
 114                if (var->pixclock == par->regs->clk_vector[i])
 115                        break;
 116        }
 117        if (i <= 3)
 118                par->clk_sel = i;
 119        else
 120                return -EINVAL;
 121
 122        switch (info->var.bits_per_pixel) {
 123        case 8:
 124                var->red   = (struct fb_bitfield) {0, 8, 0};      /* offset, length, msb-right */
 125                var->green = (struct fb_bitfield) {0, 8, 0};
 126                var->blue  = (struct fb_bitfield) {0, 8, 0};
 127                var->transp = (struct fb_bitfield) {0, 0, 0};
 128                break;
 129        case 16:
 130                var->red   = (struct fb_bitfield) {11, 5, 0};
 131                var->green = (struct fb_bitfield) {5, 6, 0};
 132                var->blue  = (struct fb_bitfield) {0, 5, 0};
 133                var->transp = (struct fb_bitfield) {0, 0, 0};
 134                break;
 135        case 24:
 136        case 32:
 137                var->red   = (struct fb_bitfield) {16, 8, 0};
 138                var->green = (struct fb_bitfield) {8, 8, 0};
 139                var->blue  = (struct fb_bitfield) {0, 8, 0};
 140                var->transp = (struct fb_bitfield) {24, 8, 0};
 141                break;
 142        default:
 143                return -EINVAL;
 144        }
 145
 146        return 0;
 147}
 148
 149static int grvga_set_par(struct fb_info *info)
 150{
 151
 152        u32 func = 0;
 153        struct grvga_par *par = info->par;
 154
 155        __raw_writel(((info->var.yres - 1) << 16) | (info->var.xres - 1),
 156                     &par->regs->video_length);
 157
 158        __raw_writel((info->var.lower_margin << 16) | (info->var.right_margin),
 159                     &par->regs->front_porch);
 160
 161        __raw_writel((info->var.vsync_len << 16) | (info->var.hsync_len),
 162                     &par->regs->sync_length);
 163
 164        __raw_writel(((info->var.yres + info->var.lower_margin + info->var.upper_margin + info->var.vsync_len - 1) << 16) |
 165                     (info->var.xres + info->var.right_margin + info->var.left_margin + info->var.hsync_len - 1),
 166                     &par->regs->line_length);
 167
 168        switch (info->var.bits_per_pixel) {
 169        case 8:
 170                info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
 171                func = 1;
 172                break;
 173        case 16:
 174                info->fix.visual = FB_VISUAL_TRUECOLOR;
 175                func = 2;
 176                break;
 177        case 24:
 178        case 32:
 179                info->fix.visual = FB_VISUAL_TRUECOLOR;
 180                func = 3;
 181                break;
 182        default:
 183                return -EINVAL;
 184        }
 185
 186        __raw_writel((par->clk_sel << 6) | (func << 4) | 1,
 187                     &par->regs->status);
 188
 189        info->fix.line_length = (info->var.xres_virtual*info->var.bits_per_pixel)/8;
 190        return 0;
 191}
 192
 193static int grvga_setcolreg(unsigned regno, unsigned red, unsigned green, unsigned blue, unsigned transp, struct fb_info *info)
 194{
 195        struct grvga_par *par;
 196        par = info->par;
 197
 198        if (regno >= 256)       /* Size of CLUT */
 199                return -EINVAL;
 200
 201        if (info->var.grayscale) {
 202                /* grayscale = 0.30*R + 0.59*G + 0.11*B */
 203                red = green = blue = (red * 77 + green * 151 + blue * 28) >> 8;
 204        }
 205
 206
 207
 208#define CNVT_TOHW(val, width) ((((val)<<(width))+0x7FFF-(val))>>16)
 209
 210        red    = CNVT_TOHW(red,   info->var.red.length);
 211        green  = CNVT_TOHW(green, info->var.green.length);
 212        blue   = CNVT_TOHW(blue,  info->var.blue.length);
 213        transp = CNVT_TOHW(transp, info->var.transp.length);
 214
 215#undef CNVT_TOHW
 216
 217        /* In PSEUDOCOLOR we use the hardware CLUT */
 218        if (info->fix.visual == FB_VISUAL_PSEUDOCOLOR)
 219                __raw_writel((regno << 24) | (red << 16) | (green << 8) | blue,
 220                             &par->regs->clut);
 221
 222        /* Truecolor uses the pseudo palette */
 223        else if (info->fix.visual == FB_VISUAL_TRUECOLOR) {
 224                u32 v;
 225                if (regno >= 16)
 226                        return -EINVAL;
 227
 228
 229                v =     (red    << info->var.red.offset)   |
 230                        (green  << info->var.green.offset) |
 231                        (blue   << info->var.blue.offset)  |
 232                        (transp << info->var.transp.offset);
 233
 234                ((u32 *) (info->pseudo_palette))[regno] = v;
 235        }
 236        return 0;
 237}
 238
 239static int grvga_pan_display(struct fb_var_screeninfo *var,
 240                             struct fb_info *info)
 241{
 242        struct grvga_par *par = info->par;
 243        struct fb_fix_screeninfo *fix = &info->fix;
 244        u32 base_addr;
 245
 246        if (var->xoffset != 0)
 247                return -EINVAL;
 248
 249        base_addr = fix->smem_start + (var->yoffset * fix->line_length);
 250        base_addr &= ~3UL;
 251
 252        /* Set framebuffer base address  */
 253        __raw_writel(base_addr,
 254                     &par->regs->fb_pos);
 255
 256        return 0;
 257}
 258
 259static struct fb_ops grvga_ops = {
 260        .owner          = THIS_MODULE,
 261        .fb_check_var   = grvga_check_var,
 262        .fb_set_par     = grvga_set_par,
 263        .fb_setcolreg   = grvga_setcolreg,
 264        .fb_pan_display = grvga_pan_display,
 265        .fb_fillrect    = cfb_fillrect,
 266        .fb_copyarea    = cfb_copyarea,
 267        .fb_imageblit   = cfb_imageblit
 268};
 269
 270static int grvga_parse_custom(char *options,
 271                              struct fb_var_screeninfo *screendata)
 272{
 273        char *this_opt;
 274        int count = 0;
 275        if (!options || !*options)
 276                return -1;
 277
 278        while ((this_opt = strsep(&options, " ")) != NULL) {
 279                if (!*this_opt)
 280                        continue;
 281
 282                switch (count) {
 283                case 0:
 284                        screendata->pixclock = simple_strtoul(this_opt, NULL, 0);
 285                        count++;
 286                        break;
 287                case 1:
 288                        screendata->xres = screendata->xres_virtual = simple_strtoul(this_opt, NULL, 0);
 289                        count++;
 290                        break;
 291                case 2:
 292                        screendata->right_margin = simple_strtoul(this_opt, NULL, 0);
 293                        count++;
 294                        break;
 295                case 3:
 296                        screendata->hsync_len = simple_strtoul(this_opt, NULL, 0);
 297                        count++;
 298                        break;
 299                case 4:
 300                        screendata->left_margin = simple_strtoul(this_opt, NULL, 0);
 301                        count++;
 302                        break;
 303                case 5:
 304                        screendata->yres = screendata->yres_virtual = simple_strtoul(this_opt, NULL, 0);
 305                        count++;
 306                        break;
 307                case 6:
 308                        screendata->lower_margin = simple_strtoul(this_opt, NULL, 0);
 309                        count++;
 310                        break;
 311                case 7:
 312                        screendata->vsync_len = simple_strtoul(this_opt, NULL, 0);
 313                        count++;
 314                        break;
 315                case 8:
 316                        screendata->upper_margin = simple_strtoul(this_opt, NULL, 0);
 317                        count++;
 318                        break;
 319                case 9:
 320                        screendata->bits_per_pixel = simple_strtoul(this_opt, NULL, 0);
 321                        count++;
 322                        break;
 323                default:
 324                        return -1;
 325                }
 326        }
 327        screendata->activate  = FB_ACTIVATE_NOW;
 328        screendata->vmode     = FB_VMODE_NONINTERLACED;
 329        return 0;
 330}
 331
 332static int grvga_probe(struct platform_device *dev)
 333{
 334        struct fb_info *info;
 335        int retval = -ENOMEM;
 336        unsigned long virtual_start;
 337        unsigned long grvga_fix_addr = 0;
 338        unsigned long physical_start = 0;
 339        unsigned long grvga_mem_size = 0;
 340        struct grvga_par *par = NULL;
 341        char *options = NULL, *mode_opt = NULL;
 342
 343        info = framebuffer_alloc(sizeof(struct grvga_par), &dev->dev);
 344        if (!info) {
 345                dev_err(&dev->dev, "framebuffer_alloc failed\n");
 346                return -ENOMEM;
 347        }
 348
 349        /* Expecting: "grvga: modestring, [addr:<framebuffer physical address>], [size:<framebuffer size>]
 350         *
 351         * If modestring is custom:<custom mode string> we parse the string which then contains all videoparameters
 352         * If address is left out, we allocate memory,
 353         * if size is left out we only allocate enough to support the given mode.
 354         */
 355        if (fb_get_options("grvga", &options)) {
 356                retval = -ENODEV;
 357                goto free_fb;
 358        }
 359
 360        if (!options || !*options)
 361                options =  "640x480-8@60";
 362
 363        while (1) {
 364                char *this_opt = strsep(&options, ",");
 365
 366                if (!this_opt)
 367                        break;
 368
 369                if (!strncmp(this_opt, "custom", 6)) {
 370                        if (grvga_parse_custom(this_opt, &info->var) < 0) {
 371                                dev_err(&dev->dev, "Failed to parse custom mode (%s).\n", this_opt);
 372                                retval = -EINVAL;
 373                                goto free_fb;
 374                        }
 375                } else if (!strncmp(this_opt, "addr", 4))
 376                        grvga_fix_addr = simple_strtoul(this_opt + 5, NULL, 16);
 377                else if (!strncmp(this_opt, "size", 4))
 378                        grvga_mem_size = simple_strtoul(this_opt + 5, NULL, 0);
 379                else
 380                        mode_opt = this_opt;
 381        }
 382
 383        par = info->par;
 384        info->fbops = &grvga_ops;
 385        info->fix = grvga_fix;
 386        info->pseudo_palette = par->color_palette;
 387        info->flags = FBINFO_DEFAULT | FBINFO_PARTIAL_PAN_OK | FBINFO_HWACCEL_YPAN;
 388        info->fix.smem_len = grvga_mem_size;
 389
 390        if (!devm_request_mem_region(&dev->dev, dev->resource[0].start,
 391                    resource_size(&dev->resource[0]), "grlib-svgactrl regs")) {
 392                dev_err(&dev->dev, "registers already mapped\n");
 393                retval = -EBUSY;
 394                goto free_fb;
 395        }
 396
 397        par->regs = of_ioremap(&dev->resource[0], 0,
 398                               resource_size(&dev->resource[0]),
 399                               "grlib-svgactrl regs");
 400
 401        if (!par->regs) {
 402                dev_err(&dev->dev, "failed to map registers\n");
 403                retval = -ENOMEM;
 404                goto free_fb;
 405        }
 406
 407        retval = fb_alloc_cmap(&info->cmap, 256, 0);
 408        if (retval < 0) {
 409                dev_err(&dev->dev, "failed to allocate mem with fb_alloc_cmap\n");
 410                retval = -ENOMEM;
 411                goto unmap_regs;
 412        }
 413
 414        if (mode_opt) {
 415                retval = fb_find_mode(&info->var, info, mode_opt,
 416                                      grvga_modedb, sizeof(grvga_modedb), &grvga_modedb[0], 8);
 417                if (!retval || retval == 4) {
 418                        retval = -EINVAL;
 419                        goto dealloc_cmap;
 420                }
 421        }
 422
 423        if (!grvga_mem_size)
 424                grvga_mem_size = info->var.xres_virtual * info->var.yres_virtual * info->var.bits_per_pixel/8;
 425
 426        if (grvga_fix_addr) {
 427                /* Got framebuffer base address from argument list */
 428
 429                physical_start = grvga_fix_addr;
 430
 431                if (!devm_request_mem_region(&dev->dev, physical_start,
 432                                             grvga_mem_size, dev->name)) {
 433                        dev_err(&dev->dev, "failed to request memory region\n");
 434                        retval = -ENOMEM;
 435                        goto dealloc_cmap;
 436                }
 437
 438                virtual_start = (unsigned long) ioremap(physical_start, grvga_mem_size);
 439
 440                if (!virtual_start) {
 441                        dev_err(&dev->dev, "error mapping framebuffer memory\n");
 442                        retval = -ENOMEM;
 443                        goto dealloc_cmap;
 444                }
 445        } else {        /* Allocate frambuffer memory */
 446
 447                unsigned long page;
 448
 449                virtual_start = (unsigned long) __get_free_pages(GFP_DMA,
 450                                                                 get_order(grvga_mem_size));
 451                if (!virtual_start) {
 452                        dev_err(&dev->dev,
 453                                "unable to allocate framebuffer memory (%lu bytes)\n",
 454                                grvga_mem_size);
 455                        retval = -ENOMEM;
 456                        goto dealloc_cmap;
 457                }
 458
 459                physical_start = dma_map_single(&dev->dev, (void *)virtual_start, grvga_mem_size, DMA_TO_DEVICE);
 460
 461                /* Set page reserved so that mmap will work. This is necessary
 462                 * since we'll be remapping normal memory.
 463                 */
 464                for (page = virtual_start;
 465                     page < PAGE_ALIGN(virtual_start + grvga_mem_size);
 466                     page += PAGE_SIZE) {
 467                        SetPageReserved(virt_to_page(page));
 468                }
 469
 470                par->fb_alloced = 1;
 471        }
 472
 473        memset((unsigned long *) virtual_start, 0, grvga_mem_size);
 474
 475        info->screen_base = (char __iomem *) virtual_start;
 476        info->fix.smem_start = physical_start;
 477        info->fix.smem_len   = grvga_mem_size;
 478
 479        dev_set_drvdata(&dev->dev, info);
 480
 481        dev_info(&dev->dev,
 482                 "Aeroflex Gaisler framebuffer device (fb%d), %dx%d-%d, using %luK of video memory @ %p\n",
 483                 info->node, info->var.xres, info->var.yres, info->var.bits_per_pixel,
 484                 grvga_mem_size >> 10, info->screen_base);
 485
 486        retval = register_framebuffer(info);
 487        if (retval < 0) {
 488                dev_err(&dev->dev, "failed to register framebuffer\n");
 489                goto free_mem;
 490        }
 491
 492        __raw_writel(physical_start, &par->regs->fb_pos);
 493        __raw_writel(__raw_readl(&par->regs->status) | 1,  /* Enable framebuffer */
 494                     &par->regs->status);
 495
 496        return 0;
 497
 498free_mem:
 499        dev_set_drvdata(&dev->dev, NULL);
 500        if (grvga_fix_addr)
 501                iounmap((void *)virtual_start);
 502        else
 503                kfree((void *)virtual_start);
 504dealloc_cmap:
 505        fb_dealloc_cmap(&info->cmap);
 506unmap_regs:
 507        of_iounmap(&dev->resource[0], par->regs,
 508                   resource_size(&dev->resource[0]));
 509free_fb:
 510        framebuffer_release(info);
 511
 512        return retval;
 513}
 514
 515static int grvga_remove(struct platform_device *device)
 516{
 517        struct fb_info *info = dev_get_drvdata(&device->dev);
 518        struct grvga_par *par = info->par;
 519
 520        if (info) {
 521                unregister_framebuffer(info);
 522                fb_dealloc_cmap(&info->cmap);
 523
 524                of_iounmap(&device->resource[0], par->regs,
 525                           resource_size(&device->resource[0]));
 526
 527                if (!par->fb_alloced)
 528                        iounmap(info->screen_base);
 529                else
 530                        kfree((void *)info->screen_base);
 531
 532                framebuffer_release(info);
 533                dev_set_drvdata(&device->dev, NULL);
 534        }
 535
 536        return 0;
 537}
 538
 539static struct of_device_id svgactrl_of_match[] = {
 540        {
 541                .name = "GAISLER_SVGACTRL",
 542        },
 543        {
 544                .name = "01_063",
 545        },
 546        {},
 547};
 548MODULE_DEVICE_TABLE(of, svgactrl_of_match);
 549
 550static struct platform_driver grvga_driver = {
 551        .driver = {
 552                .name = "grlib-svgactrl",
 553                .owner = THIS_MODULE,
 554                .of_match_table = svgactrl_of_match,
 555        },
 556        .probe          = grvga_probe,
 557        .remove         = grvga_remove,
 558};
 559
 560
 561static int __init grvga_init(void)
 562{
 563        return platform_driver_register(&grvga_driver);
 564}
 565
 566static void __exit grvga_exit(void)
 567{
 568        platform_driver_unregister(&grvga_driver);
 569}
 570
 571module_init(grvga_init);
 572module_exit(grvga_exit);
 573
 574MODULE_LICENSE("GPL");
 575MODULE_AUTHOR("Aeroflex Gaisler");
 576MODULE_DESCRIPTION("Aeroflex Gaisler framebuffer device driver");
 577
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