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