linux/drivers/video/acornfb.c
<<
>>
Prefs
   1/*
   2 *  linux/drivers/video/acornfb.c
   3 *
   4 *  Copyright (C) 1998-2001 Russell King
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License version 2 as
   8 * published by the Free Software Foundation.
   9 *
  10 * Frame buffer code for Acorn platforms
  11 *
  12 * NOTE: Most of the modes with X!=640 will disappear shortly.
  13 * NOTE: Startup setting of HS & VS polarity not supported.
  14 *       (do we need to support it if we're coming up in 640x480?)
  15 *
  16 * FIXME: (things broken by the "new improved" FBCON API)
  17 *  - Blanking 8bpp displays with VIDC
  18 */
  19
  20#include <linux/module.h>
  21#include <linux/kernel.h>
  22#include <linux/errno.h>
  23#include <linux/string.h>
  24#include <linux/ctype.h>
  25#include <linux/mm.h>
  26#include <linux/init.h>
  27#include <linux/fb.h>
  28#include <linux/platform_device.h>
  29#include <linux/dma-mapping.h>
  30#include <linux/io.h>
  31#include <linux/gfp.h>
  32
  33#include <mach/hardware.h>
  34#include <asm/irq.h>
  35#include <asm/mach-types.h>
  36#include <asm/pgtable.h>
  37
  38#include "acornfb.h"
  39
  40/*
  41 * VIDC machines can't do 16 or 32BPP modes.
  42 */
  43#ifdef HAS_VIDC
  44#undef FBCON_HAS_CFB16
  45#undef FBCON_HAS_CFB32
  46#endif
  47
  48/*
  49 * Default resolution.
  50 * NOTE that it has to be supported in the table towards
  51 * the end of this file.
  52 */
  53#define DEFAULT_XRES    640
  54#define DEFAULT_YRES    480
  55#define DEFAULT_BPP     4
  56
  57/*
  58 * define this to debug the video mode selection
  59 */
  60#undef DEBUG_MODE_SELECTION
  61
  62/*
  63 * Translation from RISC OS monitor types to actual
  64 * HSYNC and VSYNC frequency ranges.  These are
  65 * probably not right, but they're the best info I
  66 * have.  Allow 1% either way on the nominal for TVs.
  67 */
  68#define NR_MONTYPES     6
  69static struct fb_monspecs monspecs[NR_MONTYPES] = {
  70        {       /* TV           */
  71                .hfmin  = 15469,
  72                .hfmax  = 15781,
  73                .vfmin  = 49,
  74                .vfmax  = 51,
  75        }, {    /* Multi Freq   */
  76                .hfmin  = 0,
  77                .hfmax  = 99999,
  78                .vfmin  = 0,
  79                .vfmax  = 199,
  80        }, {    /* Hi-res mono  */
  81                .hfmin  = 58608,
  82                .hfmax  = 58608,
  83                .vfmin  = 64,
  84                .vfmax  = 64,
  85        }, {    /* VGA          */
  86                .hfmin  = 30000,
  87                .hfmax  = 70000,
  88                .vfmin  = 60,
  89                .vfmax  = 60,
  90        }, {    /* SVGA         */
  91                .hfmin  = 30000,
  92                .hfmax  = 70000,
  93                .vfmin  = 56,
  94                .vfmax  = 75,
  95        }, {
  96                .hfmin  = 30000,
  97                .hfmax  = 70000,
  98                .vfmin  = 60,
  99                .vfmax  = 60,
 100        }
 101};
 102
 103static struct fb_info fb_info;
 104static struct acornfb_par current_par;
 105static struct vidc_timing current_vidc;
 106
 107extern unsigned int vram_size;  /* set by setup.c */
 108
 109#ifdef HAS_VIDC
 110
 111#define MAX_SIZE        480*1024
 112
 113/* CTL     VIDC Actual
 114 * 24.000  0     8.000
 115 * 25.175  0     8.392
 116 * 36.000  0    12.000
 117 * 24.000  1    12.000
 118 * 25.175  1    12.588
 119 * 24.000  2    16.000
 120 * 25.175  2    16.783
 121 * 36.000  1    18.000
 122 * 24.000  3    24.000
 123 * 36.000  2    24.000
 124 * 25.175  3    25.175
 125 * 36.000  3    36.000
 126 */
 127struct pixclock {
 128        u_long  min_clock;
 129        u_long  max_clock;
 130        u_int   vidc_ctl;
 131        u_int   vid_ctl;
 132};
 133
 134static struct pixclock arc_clocks[] = {
 135        /* we allow +/-1% on these */
 136        { 123750, 126250, VIDC_CTRL_DIV3,   VID_CTL_24MHz },    /*  8.000MHz */
 137        {  82500,  84167, VIDC_CTRL_DIV2,   VID_CTL_24MHz },    /* 12.000MHz */
 138        {  61875,  63125, VIDC_CTRL_DIV1_5, VID_CTL_24MHz },    /* 16.000MHz */
 139        {  41250,  42083, VIDC_CTRL_DIV1,   VID_CTL_24MHz },    /* 24.000MHz */
 140};
 141
 142static struct pixclock *
 143acornfb_valid_pixrate(struct fb_var_screeninfo *var)
 144{
 145        u_long pixclock = var->pixclock;
 146        u_int i;
 147
 148        if (!var->pixclock)
 149                return NULL;
 150
 151        for (i = 0; i < ARRAY_SIZE(arc_clocks); i++)
 152                if (pixclock > arc_clocks[i].min_clock &&
 153                    pixclock < arc_clocks[i].max_clock)
 154                        return arc_clocks + i;
 155
 156        return NULL;
 157}
 158
 159/* VIDC Rules:
 160 * hcr  : must be even (interlace, hcr/2 must be even)
 161 * hswr : must be even
 162 * hdsr : must be odd
 163 * hder : must be odd
 164 *
 165 * vcr  : must be odd
 166 * vswr : >= 1
 167 * vdsr : >= 1
 168 * vder : >= vdsr
 169 * if interlaced, then hcr/2 must be even
 170 */
 171static void
 172acornfb_set_timing(struct fb_var_screeninfo *var)
 173{
 174        struct pixclock *pclk;
 175        struct vidc_timing vidc;
 176        u_int horiz_correction;
 177        u_int sync_len, display_start, display_end, cycle;
 178        u_int is_interlaced;
 179        u_int vid_ctl, vidc_ctl;
 180        u_int bandwidth;
 181
 182        memset(&vidc, 0, sizeof(vidc));
 183
 184        pclk = acornfb_valid_pixrate(var);
 185        vidc_ctl = pclk->vidc_ctl;
 186        vid_ctl  = pclk->vid_ctl;
 187
 188        bandwidth = var->pixclock * 8 / var->bits_per_pixel;
 189        /* 25.175, 4bpp = 79.444ns per byte, 317.776ns per word: fifo = 2,6 */
 190        if (bandwidth > 143500)
 191                vidc_ctl |= VIDC_CTRL_FIFO_3_7;
 192        else if (bandwidth > 71750)
 193                vidc_ctl |= VIDC_CTRL_FIFO_2_6;
 194        else if (bandwidth > 35875)
 195                vidc_ctl |= VIDC_CTRL_FIFO_1_5;
 196        else
 197                vidc_ctl |= VIDC_CTRL_FIFO_0_4;
 198
 199        switch (var->bits_per_pixel) {
 200        case 1:
 201                horiz_correction = 19;
 202                vidc_ctl |= VIDC_CTRL_1BPP;
 203                break;
 204
 205        case 2:
 206                horiz_correction = 11;
 207                vidc_ctl |= VIDC_CTRL_2BPP;
 208                break;
 209
 210        case 4:
 211                horiz_correction = 7;
 212                vidc_ctl |= VIDC_CTRL_4BPP;
 213                break;
 214
 215        default:
 216        case 8:
 217                horiz_correction = 5;
 218                vidc_ctl |= VIDC_CTRL_8BPP;
 219                break;
 220        }
 221
 222        if (var->sync & FB_SYNC_COMP_HIGH_ACT) /* should be FB_SYNC_COMP */
 223                vidc_ctl |= VIDC_CTRL_CSYNC;
 224        else {
 225                if (!(var->sync & FB_SYNC_HOR_HIGH_ACT))
 226                        vid_ctl |= VID_CTL_HS_NHSYNC;
 227
 228                if (!(var->sync & FB_SYNC_VERT_HIGH_ACT))
 229                        vid_ctl |= VID_CTL_VS_NVSYNC;
 230        }
 231
 232        sync_len        = var->hsync_len;
 233        display_start   = sync_len + var->left_margin;
 234        display_end     = display_start + var->xres;
 235        cycle           = display_end + var->right_margin;
 236
 237        /* if interlaced, then hcr/2 must be even */
 238        is_interlaced = (var->vmode & FB_VMODE_MASK) == FB_VMODE_INTERLACED;
 239
 240        if (is_interlaced) {
 241                vidc_ctl |= VIDC_CTRL_INTERLACE;
 242                if (cycle & 2) {
 243                        cycle += 2;
 244                        var->right_margin += 2;
 245                }
 246        }
 247
 248        vidc.h_cycle            = (cycle - 2) / 2;
 249        vidc.h_sync_width       = (sync_len - 2) / 2;
 250        vidc.h_border_start     = (display_start - 1) / 2;
 251        vidc.h_display_start    = (display_start - horiz_correction) / 2;
 252        vidc.h_display_end      = (display_end - horiz_correction) / 2;
 253        vidc.h_border_end       = (display_end - 1) / 2;
 254        vidc.h_interlace        = (vidc.h_cycle + 1) / 2;
 255
 256        sync_len        = var->vsync_len;
 257        display_start   = sync_len + var->upper_margin;
 258        display_end     = display_start + var->yres;
 259        cycle           = display_end + var->lower_margin;
 260
 261        if (is_interlaced)
 262                cycle = (cycle - 3) / 2;
 263        else
 264                cycle = cycle - 1;
 265
 266        vidc.v_cycle            = cycle;
 267        vidc.v_sync_width       = sync_len - 1;
 268        vidc.v_border_start     = display_start - 1;
 269        vidc.v_display_start    = vidc.v_border_start;
 270        vidc.v_display_end      = display_end - 1;
 271        vidc.v_border_end       = vidc.v_display_end;
 272
 273        if (machine_is_a5k())
 274                __raw_writeb(vid_ctl, IOEB_VID_CTL);
 275
 276        if (memcmp(&current_vidc, &vidc, sizeof(vidc))) {
 277                current_vidc = vidc;
 278
 279                vidc_writel(0xe0000000 | vidc_ctl);
 280                vidc_writel(0x80000000 | (vidc.h_cycle << 14));
 281                vidc_writel(0x84000000 | (vidc.h_sync_width << 14));
 282                vidc_writel(0x88000000 | (vidc.h_border_start << 14));
 283                vidc_writel(0x8c000000 | (vidc.h_display_start << 14));
 284                vidc_writel(0x90000000 | (vidc.h_display_end << 14));
 285                vidc_writel(0x94000000 | (vidc.h_border_end << 14));
 286                vidc_writel(0x98000000);
 287                vidc_writel(0x9c000000 | (vidc.h_interlace << 14));
 288                vidc_writel(0xa0000000 | (vidc.v_cycle << 14));
 289                vidc_writel(0xa4000000 | (vidc.v_sync_width << 14));
 290                vidc_writel(0xa8000000 | (vidc.v_border_start << 14));
 291                vidc_writel(0xac000000 | (vidc.v_display_start << 14));
 292                vidc_writel(0xb0000000 | (vidc.v_display_end << 14));
 293                vidc_writel(0xb4000000 | (vidc.v_border_end << 14));
 294                vidc_writel(0xb8000000);
 295                vidc_writel(0xbc000000);
 296        }
 297#ifdef DEBUG_MODE_SELECTION
 298        printk(KERN_DEBUG "VIDC registers for %dx%dx%d:\n", var->xres,
 299               var->yres, var->bits_per_pixel);
 300        printk(KERN_DEBUG " H-cycle          : %d\n", vidc.h_cycle);
 301        printk(KERN_DEBUG " H-sync-width     : %d\n", vidc.h_sync_width);
 302        printk(KERN_DEBUG " H-border-start   : %d\n", vidc.h_border_start);
 303        printk(KERN_DEBUG " H-display-start  : %d\n", vidc.h_display_start);
 304        printk(KERN_DEBUG " H-display-end    : %d\n", vidc.h_display_end);
 305        printk(KERN_DEBUG " H-border-end     : %d\n", vidc.h_border_end);
 306        printk(KERN_DEBUG " H-interlace      : %d\n", vidc.h_interlace);
 307        printk(KERN_DEBUG " V-cycle          : %d\n", vidc.v_cycle);
 308        printk(KERN_DEBUG " V-sync-width     : %d\n", vidc.v_sync_width);
 309        printk(KERN_DEBUG " V-border-start   : %d\n", vidc.v_border_start);
 310        printk(KERN_DEBUG " V-display-start  : %d\n", vidc.v_display_start);
 311        printk(KERN_DEBUG " V-display-end    : %d\n", vidc.v_display_end);
 312        printk(KERN_DEBUG " V-border-end     : %d\n", vidc.v_border_end);
 313        printk(KERN_DEBUG " VIDC Ctrl (E)    : 0x%08X\n", vidc_ctl);
 314        printk(KERN_DEBUG " IOEB Ctrl        : 0x%08X\n", vid_ctl);
 315#endif
 316}
 317
 318static int
 319acornfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
 320                  u_int trans, struct fb_info *info)
 321{
 322        union palette pal;
 323
 324        if (regno >= current_par.palette_size)
 325                return 1;
 326
 327        pal.p = 0;
 328        pal.vidc.reg   = regno;
 329        pal.vidc.red   = red >> 12;
 330        pal.vidc.green = green >> 12;
 331        pal.vidc.blue  = blue >> 12;
 332
 333        current_par.palette[regno] = pal;
 334
 335        vidc_writel(pal.p);
 336
 337        return 0;
 338}
 339#endif
 340
 341#ifdef HAS_VIDC20
 342#include <mach/acornfb.h>
 343
 344#define MAX_SIZE        2*1024*1024
 345
 346/* VIDC20 has a different set of rules from the VIDC:
 347 *  hcr  : must be multiple of 4
 348 *  hswr : must be even
 349 *  hdsr : must be even
 350 *  hder : must be even
 351 *  vcr  : >= 2, (interlace, must be odd)
 352 *  vswr : >= 1
 353 *  vdsr : >= 1
 354 *  vder : >= vdsr
 355 */
 356static void acornfb_set_timing(struct fb_info *info)
 357{
 358        struct fb_var_screeninfo *var = &info->var;
 359        struct vidc_timing vidc;
 360        u_int vcr, fsize;
 361        u_int ext_ctl, dat_ctl;
 362        u_int words_per_line;
 363
 364        memset(&vidc, 0, sizeof(vidc));
 365
 366        vidc.h_sync_width       = var->hsync_len - 8;
 367        vidc.h_border_start     = vidc.h_sync_width + var->left_margin + 8 - 12;
 368        vidc.h_display_start    = vidc.h_border_start + 12 - 18;
 369        vidc.h_display_end      = vidc.h_display_start + var->xres;
 370        vidc.h_border_end       = vidc.h_display_end + 18 - 12;
 371        vidc.h_cycle            = vidc.h_border_end + var->right_margin + 12 - 8;
 372        vidc.h_interlace        = vidc.h_cycle / 2;
 373        vidc.v_sync_width       = var->vsync_len - 1;
 374        vidc.v_border_start     = vidc.v_sync_width + var->upper_margin;
 375        vidc.v_display_start    = vidc.v_border_start;
 376        vidc.v_display_end      = vidc.v_display_start + var->yres;
 377        vidc.v_border_end       = vidc.v_display_end;
 378        vidc.control            = acornfb_default_control();
 379
 380        vcr = var->vsync_len + var->upper_margin + var->yres +
 381              var->lower_margin;
 382
 383        if ((var->vmode & FB_VMODE_MASK) == FB_VMODE_INTERLACED) {
 384                vidc.v_cycle = (vcr - 3) / 2;
 385                vidc.control |= VIDC20_CTRL_INT;
 386        } else
 387                vidc.v_cycle = vcr - 2;
 388
 389        switch (var->bits_per_pixel) {
 390        case  1: vidc.control |= VIDC20_CTRL_1BPP;      break;
 391        case  2: vidc.control |= VIDC20_CTRL_2BPP;      break;
 392        case  4: vidc.control |= VIDC20_CTRL_4BPP;      break;
 393        default:
 394        case  8: vidc.control |= VIDC20_CTRL_8BPP;      break;
 395        case 16: vidc.control |= VIDC20_CTRL_16BPP;     break;
 396        case 32: vidc.control |= VIDC20_CTRL_32BPP;     break;
 397        }
 398
 399        acornfb_vidc20_find_rates(&vidc, var);
 400        fsize = var->vsync_len + var->upper_margin + var->lower_margin - 1;
 401
 402        if (memcmp(&current_vidc, &vidc, sizeof(vidc))) {
 403                current_vidc = vidc;
 404
 405                vidc_writel(VIDC20_CTRL| vidc.control);
 406                vidc_writel(0xd0000000 | vidc.pll_ctl);
 407                vidc_writel(0x80000000 | vidc.h_cycle);
 408                vidc_writel(0x81000000 | vidc.h_sync_width);
 409                vidc_writel(0x82000000 | vidc.h_border_start);
 410                vidc_writel(0x83000000 | vidc.h_display_start);
 411                vidc_writel(0x84000000 | vidc.h_display_end);
 412                vidc_writel(0x85000000 | vidc.h_border_end);
 413                vidc_writel(0x86000000);
 414                vidc_writel(0x87000000 | vidc.h_interlace);
 415                vidc_writel(0x90000000 | vidc.v_cycle);
 416                vidc_writel(0x91000000 | vidc.v_sync_width);
 417                vidc_writel(0x92000000 | vidc.v_border_start);
 418                vidc_writel(0x93000000 | vidc.v_display_start);
 419                vidc_writel(0x94000000 | vidc.v_display_end);
 420                vidc_writel(0x95000000 | vidc.v_border_end);
 421                vidc_writel(0x96000000);
 422                vidc_writel(0x97000000);
 423        }
 424
 425        iomd_writel(fsize, IOMD_FSIZE);
 426
 427        ext_ctl = acornfb_default_econtrol();
 428
 429        if (var->sync & FB_SYNC_COMP_HIGH_ACT) /* should be FB_SYNC_COMP */
 430                ext_ctl |= VIDC20_ECTL_HS_NCSYNC | VIDC20_ECTL_VS_NCSYNC;
 431        else {
 432                if (var->sync & FB_SYNC_HOR_HIGH_ACT)
 433                        ext_ctl |= VIDC20_ECTL_HS_HSYNC;
 434                else
 435                        ext_ctl |= VIDC20_ECTL_HS_NHSYNC;
 436
 437                if (var->sync & FB_SYNC_VERT_HIGH_ACT)
 438                        ext_ctl |= VIDC20_ECTL_VS_VSYNC;
 439                else
 440                        ext_ctl |= VIDC20_ECTL_VS_NVSYNC;
 441        }
 442
 443        vidc_writel(VIDC20_ECTL | ext_ctl);
 444
 445        words_per_line = var->xres * var->bits_per_pixel / 32;
 446
 447        if (current_par.using_vram && info->fix.smem_len == 2048*1024)
 448                words_per_line /= 2;
 449
 450        /* RiscPC doesn't use the VIDC's VRAM control. */
 451        dat_ctl = VIDC20_DCTL_VRAM_DIS | VIDC20_DCTL_SNA | words_per_line;
 452
 453        /* The data bus width is dependent on both the type
 454         * and amount of video memory.
 455         *     DRAM     32bit low
 456         * 1MB VRAM     32bit
 457         * 2MB VRAM     64bit
 458         */
 459        if (current_par.using_vram && current_par.vram_half_sam == 2048)
 460                dat_ctl |= VIDC20_DCTL_BUS_D63_0;
 461        else
 462                dat_ctl |= VIDC20_DCTL_BUS_D31_0;
 463
 464        vidc_writel(VIDC20_DCTL | dat_ctl);
 465
 466#ifdef DEBUG_MODE_SELECTION
 467        printk(KERN_DEBUG "VIDC registers for %dx%dx%d:\n", var->xres,
 468               var->yres, var->bits_per_pixel);
 469        printk(KERN_DEBUG " H-cycle          : %d\n", vidc.h_cycle);
 470        printk(KERN_DEBUG " H-sync-width     : %d\n", vidc.h_sync_width);
 471        printk(KERN_DEBUG " H-border-start   : %d\n", vidc.h_border_start);
 472        printk(KERN_DEBUG " H-display-start  : %d\n", vidc.h_display_start);
 473        printk(KERN_DEBUG " H-display-end    : %d\n", vidc.h_display_end);
 474        printk(KERN_DEBUG " H-border-end     : %d\n", vidc.h_border_end);
 475        printk(KERN_DEBUG " H-interlace      : %d\n", vidc.h_interlace);
 476        printk(KERN_DEBUG " V-cycle          : %d\n", vidc.v_cycle);
 477        printk(KERN_DEBUG " V-sync-width     : %d\n", vidc.v_sync_width);
 478        printk(KERN_DEBUG " V-border-start   : %d\n", vidc.v_border_start);
 479        printk(KERN_DEBUG " V-display-start  : %d\n", vidc.v_display_start);
 480        printk(KERN_DEBUG " V-display-end    : %d\n", vidc.v_display_end);
 481        printk(KERN_DEBUG " V-border-end     : %d\n", vidc.v_border_end);
 482        printk(KERN_DEBUG " Ext Ctrl  (C)    : 0x%08X\n", ext_ctl);
 483        printk(KERN_DEBUG " PLL Ctrl  (D)    : 0x%08X\n", vidc.pll_ctl);
 484        printk(KERN_DEBUG " Ctrl      (E)    : 0x%08X\n", vidc.control);
 485        printk(KERN_DEBUG " Data Ctrl (F)    : 0x%08X\n", dat_ctl);
 486        printk(KERN_DEBUG " Fsize            : 0x%08X\n", fsize);
 487#endif
 488}
 489
 490/*
 491 * We have to take note of the VIDC20's 16-bit palette here.
 492 * The VIDC20 looks up a 16 bit pixel as follows:
 493 *
 494 *   bits   111111
 495 *          5432109876543210
 496 *   red            ++++++++  (8 bits,  7 to 0)
 497 *  green       ++++++++      (8 bits, 11 to 4)
 498 *   blue   ++++++++          (8 bits, 15 to 8)
 499 *
 500 * We use a pixel which looks like:
 501 *
 502 *   bits   111111
 503 *          5432109876543210
 504 *   red               +++++  (5 bits,  4 to  0)
 505 *  green         +++++       (5 bits,  9 to  5)
 506 *   blue    +++++            (5 bits, 14 to 10)
 507 */
 508static int
 509acornfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
 510                  u_int trans, struct fb_info *info)
 511{
 512        union palette pal;
 513
 514        if (regno >= current_par.palette_size)
 515                return 1;
 516
 517        if (regno < 16 && info->fix.visual == FB_VISUAL_DIRECTCOLOR) {
 518                u32 pseudo_val;
 519
 520                pseudo_val  = regno << info->var.red.offset;
 521                pseudo_val |= regno << info->var.green.offset;
 522                pseudo_val |= regno << info->var.blue.offset;
 523
 524                ((u32 *)info->pseudo_palette)[regno] = pseudo_val;
 525        }
 526
 527        pal.p = 0;
 528        pal.vidc20.red   = red >> 8;
 529        pal.vidc20.green = green >> 8;
 530        pal.vidc20.blue  = blue >> 8;
 531
 532        current_par.palette[regno] = pal;
 533
 534        if (info->var.bits_per_pixel == 16) {
 535                int i;
 536
 537                pal.p = 0;
 538                vidc_writel(0x10000000);
 539                for (i = 0; i < 256; i += 1) {
 540                        pal.vidc20.red   = current_par.palette[ i       & 31].vidc20.red;
 541                        pal.vidc20.green = current_par.palette[(i >> 1) & 31].vidc20.green;
 542                        pal.vidc20.blue  = current_par.palette[(i >> 2) & 31].vidc20.blue;
 543                        vidc_writel(pal.p);
 544                        /* Palette register pointer auto-increments */
 545                }
 546        } else {
 547                vidc_writel(0x10000000 | regno);
 548                vidc_writel(pal.p);
 549        }
 550
 551        return 0;
 552}
 553#endif
 554
 555/*
 556 * Before selecting the timing parameters, adjust
 557 * the resolution to fit the rules.
 558 */
 559static int
 560acornfb_adjust_timing(struct fb_info *info, struct fb_var_screeninfo *var, u_int fontht)
 561{
 562        u_int font_line_len, sam_size, min_size, size, nr_y;
 563
 564        /* xres must be even */
 565        var->xres = (var->xres + 1) & ~1;
 566
 567        /*
 568         * We don't allow xres_virtual to differ from xres
 569         */
 570        var->xres_virtual = var->xres;
 571        var->xoffset = 0;
 572
 573        if (current_par.using_vram)
 574                sam_size = current_par.vram_half_sam * 2;
 575        else
 576                sam_size = 16;
 577
 578        /*
 579         * Now, find a value for yres_virtual which allows
 580         * us to do ywrap scrolling.  The value of
 581         * yres_virtual must be such that the end of the
 582         * displayable frame buffer must be aligned with
 583         * the start of a font line.
 584         */
 585        font_line_len = var->xres * var->bits_per_pixel * fontht / 8;
 586        min_size = var->xres * var->yres * var->bits_per_pixel / 8;
 587
 588        /*
 589         * If minimum screen size is greater than that we have
 590         * available, reject it.
 591         */
 592        if (min_size > info->fix.smem_len)
 593                return -EINVAL;
 594
 595        /* Find int 'y', such that y * fll == s * sam < maxsize
 596         * y = s * sam / fll; s = maxsize / sam
 597         */
 598        for (size = info->fix.smem_len;
 599             nr_y = size / font_line_len, min_size <= size;
 600             size -= sam_size) {
 601                if (nr_y * font_line_len == size)
 602                        break;
 603        }
 604        nr_y *= fontht;
 605
 606        if (var->accel_flags & FB_ACCELF_TEXT) {
 607                if (min_size > size) {
 608                        /*
 609                         * failed, use ypan
 610                         */
 611                        size = info->fix.smem_len;
 612                        var->yres_virtual = size / (font_line_len / fontht);
 613                } else
 614                        var->yres_virtual = nr_y;
 615        } else if (var->yres_virtual > nr_y)
 616                var->yres_virtual = nr_y;
 617
 618        current_par.screen_end = info->fix.smem_start + size;
 619
 620        /*
 621         * Fix yres & yoffset if needed.
 622         */
 623        if (var->yres > var->yres_virtual)
 624                var->yres = var->yres_virtual;
 625
 626        if (var->vmode & FB_VMODE_YWRAP) {
 627                if (var->yoffset > var->yres_virtual)
 628                        var->yoffset = var->yres_virtual;
 629        } else {
 630                if (var->yoffset + var->yres > var->yres_virtual)
 631                        var->yoffset = var->yres_virtual - var->yres;
 632        }
 633
 634        /* hsync_len must be even */
 635        var->hsync_len = (var->hsync_len + 1) & ~1;
 636
 637#ifdef HAS_VIDC
 638        /* left_margin must be odd */
 639        if ((var->left_margin & 1) == 0) {
 640                var->left_margin -= 1;
 641                var->right_margin += 1;
 642        }
 643
 644        /* right_margin must be odd */
 645        var->right_margin |= 1;
 646#elif defined(HAS_VIDC20)
 647        /* left_margin must be even */
 648        if (var->left_margin & 1) {
 649                var->left_margin += 1;
 650                var->right_margin -= 1;
 651        }
 652
 653        /* right_margin must be even */
 654        if (var->right_margin & 1)
 655                var->right_margin += 1;
 656#endif
 657
 658        if (var->vsync_len < 1)
 659                var->vsync_len = 1;
 660
 661        return 0;
 662}
 663
 664static int
 665acornfb_validate_timing(struct fb_var_screeninfo *var,
 666                        struct fb_monspecs *monspecs)
 667{
 668        unsigned long hs, vs;
 669
 670        /*
 671         * hs(Hz) = 10^12 / (pixclock * xtotal)
 672         * vs(Hz) = hs(Hz) / ytotal
 673         *
 674         * No need to do long long divisions or anything
 675         * like that if you factor it correctly
 676         */
 677        hs = 1953125000 / var->pixclock;
 678        hs = hs * 512 /
 679             (var->xres + var->left_margin + var->right_margin + var->hsync_len);
 680        vs = hs /
 681             (var->yres + var->upper_margin + var->lower_margin + var->vsync_len);
 682
 683        return (vs >= monspecs->vfmin && vs <= monspecs->vfmax &&
 684                hs >= monspecs->hfmin && hs <= monspecs->hfmax) ? 0 : -EINVAL;
 685}
 686
 687static inline void
 688acornfb_update_dma(struct fb_info *info, struct fb_var_screeninfo *var)
 689{
 690        u_int off = var->yoffset * info->fix.line_length;
 691
 692#if defined(HAS_MEMC)
 693        memc_write(VDMA_INIT, off >> 2);
 694#elif defined(HAS_IOMD)
 695        iomd_writel(info->fix.smem_start + off, IOMD_VIDINIT);
 696#endif
 697}
 698
 699static int
 700acornfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
 701{
 702        u_int fontht;
 703        int err;
 704
 705        /*
 706         * FIXME: Find the font height
 707         */
 708        fontht = 8;
 709
 710        var->red.msb_right = 0;
 711        var->green.msb_right = 0;
 712        var->blue.msb_right = 0;
 713        var->transp.msb_right = 0;
 714
 715        switch (var->bits_per_pixel) {
 716        case 1: case 2: case 4: case 8:
 717                var->red.offset    = 0;
 718                var->red.length    = var->bits_per_pixel;
 719                var->green         = var->red;
 720                var->blue          = var->red;
 721                var->transp.offset = 0;
 722                var->transp.length = 0;
 723                break;
 724
 725#ifdef HAS_VIDC20
 726        case 16:
 727                var->red.offset    = 0;
 728                var->red.length    = 5;
 729                var->green.offset  = 5;
 730                var->green.length  = 5;
 731                var->blue.offset   = 10;
 732                var->blue.length   = 5;
 733                var->transp.offset = 15;
 734                var->transp.length = 1;
 735                break;
 736
 737        case 32:
 738                var->red.offset    = 0;
 739                var->red.length    = 8;
 740                var->green.offset  = 8;
 741                var->green.length  = 8;
 742                var->blue.offset   = 16;
 743                var->blue.length   = 8;
 744                var->transp.offset = 24;
 745                var->transp.length = 4;
 746                break;
 747#endif
 748        default:
 749                return -EINVAL;
 750        }
 751
 752        /*
 753         * Check to see if the pixel rate is valid.
 754         */
 755        if (!acornfb_valid_pixrate(var))
 756                return -EINVAL;
 757
 758        /*
 759         * Validate and adjust the resolution to
 760         * match the video generator hardware.
 761         */
 762        err = acornfb_adjust_timing(info, var, fontht);
 763        if (err)
 764                return err;
 765
 766        /*
 767         * Validate the timing against the
 768         * monitor hardware.
 769         */
 770        return acornfb_validate_timing(var, &info->monspecs);
 771}
 772
 773static int acornfb_set_par(struct fb_info *info)
 774{
 775        switch (info->var.bits_per_pixel) {
 776        case 1:
 777                current_par.palette_size = 2;
 778                info->fix.visual = FB_VISUAL_MONO10;
 779                break;
 780        case 2:
 781                current_par.palette_size = 4;
 782                info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
 783                break;
 784        case 4:
 785                current_par.palette_size = 16;
 786                info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
 787                break;
 788        case 8:
 789                current_par.palette_size = VIDC_PALETTE_SIZE;
 790#ifdef HAS_VIDC
 791                info->fix.visual = FB_VISUAL_STATIC_PSEUDOCOLOR;
 792#else
 793                info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
 794#endif
 795                break;
 796#ifdef HAS_VIDC20
 797        case 16:
 798                current_par.palette_size = 32;
 799                info->fix.visual = FB_VISUAL_DIRECTCOLOR;
 800                break;
 801        case 32:
 802                current_par.palette_size = VIDC_PALETTE_SIZE;
 803                info->fix.visual = FB_VISUAL_DIRECTCOLOR;
 804                break;
 805#endif
 806        default:
 807                BUG();
 808        }
 809
 810        info->fix.line_length   = (info->var.xres * info->var.bits_per_pixel) / 8;
 811
 812#if defined(HAS_MEMC)
 813        {
 814                unsigned long size = info->fix.smem_len - VDMA_XFERSIZE;
 815
 816                memc_write(VDMA_START, 0);
 817                memc_write(VDMA_END, size >> 2);
 818        }
 819#elif defined(HAS_IOMD)
 820        {
 821                unsigned long start, size;
 822                u_int control;
 823
 824                start = info->fix.smem_start;
 825                size  = current_par.screen_end;
 826
 827                if (current_par.using_vram) {
 828                        size -= current_par.vram_half_sam;
 829                        control = DMA_CR_E | (current_par.vram_half_sam / 256);
 830                } else {
 831                        size -= 16;
 832                        control = DMA_CR_E | DMA_CR_D | 16;
 833                }
 834
 835                iomd_writel(start,   IOMD_VIDSTART);
 836                iomd_writel(size,    IOMD_VIDEND);
 837                iomd_writel(control, IOMD_VIDCR);
 838        }
 839#endif
 840
 841        acornfb_update_dma(info, &info->var);
 842        acornfb_set_timing(info);
 843
 844        return 0;
 845}
 846
 847static int
 848acornfb_pan_display(struct fb_var_screeninfo *var, struct fb_info *info)
 849{
 850        u_int y_bottom = var->yoffset;
 851
 852        if (!(var->vmode & FB_VMODE_YWRAP))
 853                y_bottom += info->var.yres;
 854
 855        if (y_bottom > info->var.yres_virtual)
 856                return -EINVAL;
 857
 858        acornfb_update_dma(info, var);
 859
 860        return 0;
 861}
 862
 863static struct fb_ops acornfb_ops = {
 864        .owner          = THIS_MODULE,
 865        .fb_check_var   = acornfb_check_var,
 866        .fb_set_par     = acornfb_set_par,
 867        .fb_setcolreg   = acornfb_setcolreg,
 868        .fb_pan_display = acornfb_pan_display,
 869        .fb_fillrect    = cfb_fillrect,
 870        .fb_copyarea    = cfb_copyarea,
 871        .fb_imageblit   = cfb_imageblit,
 872};
 873
 874/*
 875 * Everything after here is initialisation!!!
 876 */
 877static struct fb_videomode modedb[] = {
 878        {       /* 320x256 @ 50Hz */
 879                NULL, 50,  320,  256, 125000,  92,  62,  35, 19,  38, 2,
 880                FB_SYNC_COMP_HIGH_ACT,
 881                FB_VMODE_NONINTERLACED
 882        }, {    /* 640x250 @ 50Hz, 15.6 kHz hsync */
 883                NULL, 50,  640,  250,  62500, 185, 123,  38, 21,  76, 3,
 884                0,
 885                FB_VMODE_NONINTERLACED
 886        }, {    /* 640x256 @ 50Hz, 15.6 kHz hsync */
 887                NULL, 50,  640,  256,  62500, 185, 123,  35, 18,  76, 3,
 888                0,
 889                FB_VMODE_NONINTERLACED
 890        }, {    /* 640x512 @ 50Hz, 26.8 kHz hsync */
 891                NULL, 50,  640,  512,  41667, 113,  87,  18,  1,  56, 3,
 892                0,
 893                FB_VMODE_NONINTERLACED
 894        }, {    /* 640x250 @ 70Hz, 31.5 kHz hsync */
 895                NULL, 70,  640,  250,  39722,  48,  16, 109, 88,  96, 2,
 896                0,
 897                FB_VMODE_NONINTERLACED
 898        }, {    /* 640x256 @ 70Hz, 31.5 kHz hsync */
 899                NULL, 70,  640,  256,  39722,  48,  16, 106, 85,  96, 2,
 900                0,
 901                FB_VMODE_NONINTERLACED
 902        }, {    /* 640x352 @ 70Hz, 31.5 kHz hsync */
 903                NULL, 70,  640,  352,  39722,  48,  16,  58, 37,  96, 2,
 904                0,
 905                FB_VMODE_NONINTERLACED
 906        }, {    /* 640x480 @ 60Hz, 31.5 kHz hsync */
 907                NULL, 60,  640,  480,  39722,  48,  16,  32, 11,  96, 2,
 908                0,
 909                FB_VMODE_NONINTERLACED
 910        }, {    /* 800x600 @ 56Hz, 35.2 kHz hsync */
 911                NULL, 56,  800,  600,  27778, 101,  23,  22,  1, 100, 2,
 912                0,
 913                FB_VMODE_NONINTERLACED
 914        }, {    /* 896x352 @ 60Hz, 21.8 kHz hsync */
 915                NULL, 60,  896,  352,  41667,  59,  27,   9,  0, 118, 3,
 916                0,
 917                FB_VMODE_NONINTERLACED
 918        }, {    /* 1024x 768 @ 60Hz, 48.4 kHz hsync */
 919                NULL, 60, 1024,  768,  15385, 160,  24,  29,  3, 136, 6,
 920                0,
 921                FB_VMODE_NONINTERLACED
 922        }, {    /* 1280x1024 @ 60Hz, 63.8 kHz hsync */
 923                NULL, 60, 1280, 1024,   9090, 186,  96,  38,  1, 160, 3,
 924                0,
 925                FB_VMODE_NONINTERLACED
 926        }
 927};
 928
 929static struct fb_videomode acornfb_default_mode = {
 930        .name =         NULL,
 931        .refresh =      60,
 932        .xres =         640,
 933        .yres =         480,
 934        .pixclock =     39722,
 935        .left_margin =  56,
 936        .right_margin = 16,
 937        .upper_margin = 34,
 938        .lower_margin = 9,
 939        .hsync_len =    88,
 940        .vsync_len =    2,
 941        .sync =         0,
 942        .vmode =        FB_VMODE_NONINTERLACED
 943};
 944
 945static void acornfb_init_fbinfo(void)
 946{
 947        static int first = 1;
 948
 949        if (!first)
 950                return;
 951        first = 0;
 952
 953        fb_info.fbops           = &acornfb_ops;
 954        fb_info.flags           = FBINFO_DEFAULT | FBINFO_HWACCEL_YPAN;
 955        fb_info.pseudo_palette  = current_par.pseudo_palette;
 956
 957        strcpy(fb_info.fix.id, "Acorn");
 958        fb_info.fix.type        = FB_TYPE_PACKED_PIXELS;
 959        fb_info.fix.type_aux    = 0;
 960        fb_info.fix.xpanstep    = 0;
 961        fb_info.fix.ypanstep    = 1;
 962        fb_info.fix.ywrapstep   = 1;
 963        fb_info.fix.line_length = 0;
 964        fb_info.fix.accel       = FB_ACCEL_NONE;
 965
 966        /*
 967         * setup initial parameters
 968         */
 969        memset(&fb_info.var, 0, sizeof(fb_info.var));
 970
 971#if defined(HAS_VIDC20)
 972        fb_info.var.red.length     = 8;
 973        fb_info.var.transp.length  = 4;
 974#elif defined(HAS_VIDC)
 975        fb_info.var.red.length     = 4;
 976        fb_info.var.transp.length  = 1;
 977#endif
 978        fb_info.var.green          = fb_info.var.red;
 979        fb_info.var.blue           = fb_info.var.red;
 980        fb_info.var.nonstd         = 0;
 981        fb_info.var.activate       = FB_ACTIVATE_NOW;
 982        fb_info.var.height         = -1;
 983        fb_info.var.width          = -1;
 984        fb_info.var.vmode          = FB_VMODE_NONINTERLACED;
 985        fb_info.var.accel_flags    = FB_ACCELF_TEXT;
 986
 987        current_par.dram_size      = 0;
 988        current_par.montype        = -1;
 989        current_par.dpms           = 0;
 990}
 991
 992/*
 993 * setup acornfb options:
 994 *
 995 *  mon:hmin-hmax:vmin-vmax:dpms:width:height
 996 *      Set monitor parameters:
 997 *              hmin   = horizontal minimum frequency (Hz)
 998 *              hmax   = horizontal maximum frequency (Hz)      (optional)
 999 *              vmin   = vertical minimum frequency (Hz)
1000 *              vmax   = vertical maximum frequency (Hz)        (optional)
1001 *              dpms   = DPMS supported?                        (optional)
1002 *              width  = width of picture in mm.                (optional)
1003 *              height = height of picture in mm.               (optional)
1004 *
1005 * montype:type
1006 *      Set RISC-OS style monitor type:
1007 *              0 (or tv)       - TV frequency
1008 *              1 (or multi)    - Multi frequency
1009 *              2 (or hires)    - Hi-res monochrome
1010 *              3 (or vga)      - VGA
1011 *              4 (or svga)     - SVGA
1012 *              auto, or option missing
1013 *                              - try hardware detect
1014 *
1015 * dram:size
1016 *      Set the amount of DRAM to use for the frame buffer
1017 *      (even if you have VRAM).
1018 *      size can optionally be followed by 'M' or 'K' for
1019 *      MB or KB respectively.
1020 */
1021static void acornfb_parse_mon(char *opt)
1022{
1023        char *p = opt;
1024
1025        current_par.montype = -2;
1026
1027        fb_info.monspecs.hfmin = simple_strtoul(p, &p, 0);
1028        if (*p == '-')
1029                fb_info.monspecs.hfmax = simple_strtoul(p + 1, &p, 0);
1030        else
1031                fb_info.monspecs.hfmax = fb_info.monspecs.hfmin;
1032
1033        if (*p != ':')
1034                goto bad;
1035
1036        fb_info.monspecs.vfmin = simple_strtoul(p + 1, &p, 0);
1037        if (*p == '-')
1038                fb_info.monspecs.vfmax = simple_strtoul(p + 1, &p, 0);
1039        else
1040                fb_info.monspecs.vfmax = fb_info.monspecs.vfmin;
1041
1042        if (*p != ':')
1043                goto check_values;
1044
1045        fb_info.monspecs.dpms = simple_strtoul(p + 1, &p, 0);
1046
1047        if (*p != ':')
1048                goto check_values;
1049
1050        fb_info.var.width = simple_strtoul(p + 1, &p, 0);
1051
1052        if (*p != ':')
1053                goto check_values;
1054
1055        fb_info.var.height = simple_strtoul(p + 1, NULL, 0);
1056
1057check_values:
1058        if (fb_info.monspecs.hfmax < fb_info.monspecs.hfmin ||
1059            fb_info.monspecs.vfmax < fb_info.monspecs.vfmin)
1060                goto bad;
1061        return;
1062
1063bad:
1064        printk(KERN_ERR "Acornfb: bad monitor settings: %s\n", opt);
1065        current_par.montype = -1;
1066}
1067
1068static void acornfb_parse_montype(char *opt)
1069{
1070        current_par.montype = -2;
1071
1072        if (strncmp(opt, "tv", 2) == 0) {
1073                opt += 2;
1074                current_par.montype = 0;
1075        } else if (strncmp(opt, "multi", 5) == 0) {
1076                opt += 5;
1077                current_par.montype = 1;
1078        } else if (strncmp(opt, "hires", 5) == 0) {
1079                opt += 5;
1080                current_par.montype = 2;
1081        } else if (strncmp(opt, "vga", 3) == 0) {
1082                opt += 3;
1083                current_par.montype = 3;
1084        } else if (strncmp(opt, "svga", 4) == 0) {
1085                opt += 4;
1086                current_par.montype = 4;
1087        } else if (strncmp(opt, "auto", 4) == 0) {
1088                opt += 4;
1089                current_par.montype = -1;
1090        } else if (isdigit(*opt))
1091                current_par.montype = simple_strtoul(opt, &opt, 0);
1092
1093        if (current_par.montype == -2 ||
1094            current_par.montype > NR_MONTYPES) {
1095                printk(KERN_ERR "acornfb: unknown monitor type: %s\n",
1096                        opt);
1097                current_par.montype = -1;
1098        } else
1099        if (opt && *opt) {
1100                if (strcmp(opt, ",dpms") == 0)
1101                        current_par.dpms = 1;
1102                else
1103                        printk(KERN_ERR
1104                               "acornfb: unknown monitor option: %s\n",
1105                               opt);
1106        }
1107}
1108
1109static void acornfb_parse_dram(char *opt)
1110{
1111        unsigned int size;
1112
1113        size = simple_strtoul(opt, &opt, 0);
1114
1115        if (opt) {
1116                switch (*opt) {
1117                case 'M':
1118                case 'm':
1119                        size *= 1024;
1120                case 'K':
1121                case 'k':
1122                        size *= 1024;
1123                default:
1124                        break;
1125                }
1126        }
1127
1128        current_par.dram_size = size;
1129}
1130
1131static struct options {
1132        char *name;
1133        void (*parse)(char *opt);
1134} opt_table[] = {
1135        { "mon",     acornfb_parse_mon     },
1136        { "montype", acornfb_parse_montype },
1137        { "dram",    acornfb_parse_dram    },
1138        { NULL, NULL }
1139};
1140
1141static int acornfb_setup(char *options)
1142{
1143        struct options *optp;
1144        char *opt;
1145
1146        if (!options || !*options)
1147                return 0;
1148
1149        acornfb_init_fbinfo();
1150
1151        while ((opt = strsep(&options, ",")) != NULL) {
1152                if (!*opt)
1153                        continue;
1154
1155                for (optp = opt_table; optp->name; optp++) {
1156                        int optlen;
1157
1158                        optlen = strlen(optp->name);
1159
1160                        if (strncmp(opt, optp->name, optlen) == 0 &&
1161                            opt[optlen] == ':') {
1162                                optp->parse(opt + optlen + 1);
1163                                break;
1164                        }
1165                }
1166
1167                if (!optp->name)
1168                        printk(KERN_ERR "acornfb: unknown parameter: %s\n",
1169                               opt);
1170        }
1171        return 0;
1172}
1173
1174/*
1175 * Detect type of monitor connected
1176 *  For now, we just assume SVGA
1177 */
1178static int acornfb_detect_monitortype(void)
1179{
1180        return 4;
1181}
1182
1183/*
1184 * This enables the unused memory to be freed on older Acorn machines.
1185 * We are freeing memory on behalf of the architecture initialisation
1186 * code here.
1187 */
1188static inline void
1189free_unused_pages(unsigned int virtual_start, unsigned int virtual_end)
1190{
1191        int mb_freed = 0;
1192
1193        /*
1194         * Align addresses
1195         */
1196        virtual_start = PAGE_ALIGN(virtual_start);
1197        virtual_end = PAGE_ALIGN(virtual_end);
1198
1199        while (virtual_start < virtual_end) {
1200                struct page *page;
1201
1202                /*
1203                 * Clear page reserved bit,
1204                 * set count to 1, and free
1205                 * the page.
1206                 */
1207                page = virt_to_page(virtual_start);
1208                ClearPageReserved(page);
1209                init_page_count(page);
1210                free_page(virtual_start);
1211
1212                virtual_start += PAGE_SIZE;
1213                mb_freed += PAGE_SIZE / 1024;
1214        }
1215
1216        printk("acornfb: freed %dK memory\n", mb_freed);
1217}
1218
1219static int acornfb_probe(struct platform_device *dev)
1220{
1221        unsigned long size;
1222        u_int h_sync, v_sync;
1223        int rc, i;
1224        char *option = NULL;
1225
1226        if (fb_get_options("acornfb", &option))
1227                return -ENODEV;
1228        acornfb_setup(option);
1229
1230        acornfb_init_fbinfo();
1231
1232        current_par.dev = &dev->dev;
1233
1234        if (current_par.montype == -1)
1235                current_par.montype = acornfb_detect_monitortype();
1236
1237        if (current_par.montype == -1 || current_par.montype > NR_MONTYPES)
1238                current_par.montype = 4;
1239
1240        if (current_par.montype >= 0) {
1241                fb_info.monspecs = monspecs[current_par.montype];
1242                fb_info.monspecs.dpms = current_par.dpms;
1243        }
1244
1245        /*
1246         * Try to select a suitable default mode
1247         */
1248        for (i = 0; i < ARRAY_SIZE(modedb); i++) {
1249                unsigned long hs;
1250
1251                hs = modedb[i].refresh *
1252                     (modedb[i].yres + modedb[i].upper_margin +
1253                      modedb[i].lower_margin + modedb[i].vsync_len);
1254                if (modedb[i].xres == DEFAULT_XRES &&
1255                    modedb[i].yres == DEFAULT_YRES &&
1256                    modedb[i].refresh >= fb_info.monspecs.vfmin &&
1257                    modedb[i].refresh <= fb_info.monspecs.vfmax &&
1258                    hs                >= fb_info.monspecs.hfmin &&
1259                    hs                <= fb_info.monspecs.hfmax) {
1260                        acornfb_default_mode = modedb[i];
1261                        break;
1262                }
1263        }
1264
1265        fb_info.screen_base    = (char *)SCREEN_BASE;
1266        fb_info.fix.smem_start = SCREEN_START;
1267        current_par.using_vram = 0;
1268
1269        /*
1270         * If vram_size is set, we are using VRAM in
1271         * a Risc PC.  However, if the user has specified
1272         * an amount of DRAM then use that instead.
1273         */
1274        if (vram_size && !current_par.dram_size) {
1275                size = vram_size;
1276                current_par.vram_half_sam = vram_size / 1024;
1277                current_par.using_vram = 1;
1278        } else if (current_par.dram_size)
1279                size = current_par.dram_size;
1280        else
1281                size = MAX_SIZE;
1282
1283        /*
1284         * Limit maximum screen size.
1285         */
1286        if (size > MAX_SIZE)
1287                size = MAX_SIZE;
1288
1289        size = PAGE_ALIGN(size);
1290
1291#if defined(HAS_VIDC20)
1292        if (!current_par.using_vram) {
1293                dma_addr_t handle;
1294                void *base;
1295
1296                /*
1297                 * RiscPC needs to allocate the DRAM memory
1298                 * for the framebuffer if we are not using
1299                 * VRAM.
1300                 */
1301                base = dma_alloc_writecombine(current_par.dev, size, &handle,
1302                                              GFP_KERNEL);
1303                if (base == NULL) {
1304                        printk(KERN_ERR "acornfb: unable to allocate screen "
1305                               "memory\n");
1306                        return -ENOMEM;
1307                }
1308
1309                fb_info.screen_base = base;
1310                fb_info.fix.smem_start = handle;
1311        }
1312#endif
1313#if defined(HAS_VIDC)
1314        /*
1315         * Archimedes/A5000 machines use a fixed address for their
1316         * framebuffers.  Free unused pages
1317         */
1318        free_unused_pages(PAGE_OFFSET + size, PAGE_OFFSET + MAX_SIZE);
1319#endif
1320
1321        fb_info.fix.smem_len = size;
1322        current_par.palette_size   = VIDC_PALETTE_SIZE;
1323
1324        /*
1325         * Lookup the timing for this resolution.  If we can't
1326         * find it, then we can't restore it if we change
1327         * the resolution, so we disable this feature.
1328         */
1329        do {
1330                rc = fb_find_mode(&fb_info.var, &fb_info, NULL, modedb,
1331                                 ARRAY_SIZE(modedb),
1332                                 &acornfb_default_mode, DEFAULT_BPP);
1333                /*
1334                 * If we found an exact match, all ok.
1335                 */
1336                if (rc == 1)
1337                        break;
1338
1339                rc = fb_find_mode(&fb_info.var, &fb_info, NULL, NULL, 0,
1340                                  &acornfb_default_mode, DEFAULT_BPP);
1341                /*
1342                 * If we found an exact match, all ok.
1343                 */
1344                if (rc == 1)
1345                        break;
1346
1347                rc = fb_find_mode(&fb_info.var, &fb_info, NULL, modedb,
1348                                 ARRAY_SIZE(modedb),
1349                                 &acornfb_default_mode, DEFAULT_BPP);
1350                if (rc)
1351                        break;
1352
1353                rc = fb_find_mode(&fb_info.var, &fb_info, NULL, NULL, 0,
1354                                  &acornfb_default_mode, DEFAULT_BPP);
1355        } while (0);
1356
1357        /*
1358         * If we didn't find an exact match, try the
1359         * generic database.
1360         */
1361        if (rc == 0) {
1362                printk("Acornfb: no valid mode found\n");
1363                return -EINVAL;
1364        }
1365
1366        h_sync = 1953125000 / fb_info.var.pixclock;
1367        h_sync = h_sync * 512 / (fb_info.var.xres + fb_info.var.left_margin +
1368                 fb_info.var.right_margin + fb_info.var.hsync_len);
1369        v_sync = h_sync / (fb_info.var.yres + fb_info.var.upper_margin +
1370                 fb_info.var.lower_margin + fb_info.var.vsync_len);
1371
1372        printk(KERN_INFO "Acornfb: %dkB %cRAM, %s, using %dx%d, "
1373                "%d.%03dkHz, %dHz\n",
1374                fb_info.fix.smem_len / 1024,
1375                current_par.using_vram ? 'V' : 'D',
1376                VIDC_NAME, fb_info.var.xres, fb_info.var.yres,
1377                h_sync / 1000, h_sync % 1000, v_sync);
1378
1379        printk(KERN_INFO "Acornfb: Monitor: %d.%03d-%d.%03dkHz, %d-%dHz%s\n",
1380                fb_info.monspecs.hfmin / 1000, fb_info.monspecs.hfmin % 1000,
1381                fb_info.monspecs.hfmax / 1000, fb_info.monspecs.hfmax % 1000,
1382                fb_info.monspecs.vfmin, fb_info.monspecs.vfmax,
1383                fb_info.monspecs.dpms ? ", DPMS" : "");
1384
1385        if (fb_set_var(&fb_info, &fb_info.var))
1386                printk(KERN_ERR "Acornfb: unable to set display parameters\n");
1387
1388        if (register_framebuffer(&fb_info) < 0)
1389                return -EINVAL;
1390        return 0;
1391}
1392
1393static struct platform_driver acornfb_driver = {
1394        .probe  = acornfb_probe,
1395        .driver = {
1396                .name   = "acornfb",
1397        },
1398};
1399
1400static int __init acornfb_init(void)
1401{
1402        return platform_driver_register(&acornfb_driver);
1403}
1404
1405module_init(acornfb_init);
1406
1407MODULE_AUTHOR("Russell King");
1408MODULE_DESCRIPTION("VIDC 1/1a/20 framebuffer driver");
1409MODULE_LICENSE("GPL");
1410