linux/drivers/video/skeletonfb.c
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   1/*
   2 * linux/drivers/video/skeletonfb.c -- Skeleton for a frame buffer device
   3 *
   4 *  Modified to new api Jan 2001 by James Simmons (jsimmons@transvirtual.com)
   5 *
   6 *  Created 28 Dec 1997 by Geert Uytterhoeven
   7 *
   8 *
   9 *  I have started rewriting this driver as a example of the upcoming new API
  10 *  The primary goal is to remove the console code from fbdev and place it
  11 *  into fbcon.c. This reduces the code and makes writing a new fbdev driver
  12 *  easy since the author doesn't need to worry about console internals. It
  13 *  also allows the ability to run fbdev without a console/tty system on top 
  14 *  of it. 
  15 *
  16 *  First the roles of struct fb_info and struct display have changed. Struct
  17 *  display will go away. The way the new framebuffer console code will
  18 *  work is that it will act to translate data about the tty/console in 
  19 *  struct vc_data to data in a device independent way in struct fb_info. Then
  20 *  various functions in struct fb_ops will be called to store the device 
  21 *  dependent state in the par field in struct fb_info and to change the 
  22 *  hardware to that state. This allows a very clean separation of the fbdev
  23 *  layer from the console layer. It also allows one to use fbdev on its own
  24 *  which is a bounus for embedded devices. The reason this approach works is  
  25 *  for each framebuffer device when used as a tty/console device is allocated
  26 *  a set of virtual terminals to it. Only one virtual terminal can be active 
  27 *  per framebuffer device. We already have all the data we need in struct 
  28 *  vc_data so why store a bunch of colormaps and other fbdev specific data
  29 *  per virtual terminal. 
  30 *
  31 *  As you can see doing this makes the con parameter pretty much useless
  32 *  for struct fb_ops functions, as it should be. Also having struct  
  33 *  fb_var_screeninfo and other data in fb_info pretty much eliminates the 
  34 *  need for get_fix and get_var. Once all drivers use the fix, var, and cmap
  35 *  fbcon can be written around these fields. This will also eliminate the
  36 *  need to regenerate struct fb_var_screeninfo, struct fb_fix_screeninfo
  37 *  struct fb_cmap every time get_var, get_fix, get_cmap functions are called
  38 *  as many drivers do now. 
  39 *
  40 *  This file is subject to the terms and conditions of the GNU General Public
  41 *  License. See the file COPYING in the main directory of this archive for
  42 *  more details.
  43 */
  44
  45#include <linux/module.h>
  46#include <linux/kernel.h>
  47#include <linux/errno.h>
  48#include <linux/string.h>
  49#include <linux/mm.h>
  50#include <linux/slab.h>
  51#include <linux/delay.h>
  52#include <linux/fb.h>
  53#include <linux/init.h>
  54#include <linux/pci.h>
  55
  56    /*
  57     *  This is just simple sample code.
  58     *
  59     *  No warranty that it actually compiles.
  60     *  Even less warranty that it actually works :-)
  61     */
  62
  63/*
  64 * Driver data
  65 */
  66static char *mode_option;
  67
  68/*
  69 *  If your driver supports multiple boards, you should make the  
  70 *  below data types arrays, or allocate them dynamically (using kmalloc()). 
  71 */ 
  72
  73/* 
  74 * This structure defines the hardware state of the graphics card. Normally
  75 * you place this in a header file in linux/include/video. This file usually
  76 * also includes register information. That allows other driver subsystems
  77 * and userland applications the ability to use the same header file to 
  78 * avoid duplicate work and easy porting of software. 
  79 */
  80struct xxx_par;
  81
  82/*
  83 * Here we define the default structs fb_fix_screeninfo and fb_var_screeninfo
  84 * if we don't use modedb. If we do use modedb see xxxfb_init how to use it
  85 * to get a fb_var_screeninfo. Otherwise define a default var as well. 
  86 */
  87static struct fb_fix_screeninfo xxxfb_fix = {
  88        .id =           "FB's name", 
  89        .type =         FB_TYPE_PACKED_PIXELS,
  90        .visual =       FB_VISUAL_PSEUDOCOLOR,
  91        .xpanstep =     1,
  92        .ypanstep =     1,
  93        .ywrapstep =    1, 
  94        .accel =        FB_ACCEL_NONE,
  95};
  96
  97    /*
  98     *  Modern graphical hardware not only supports pipelines but some 
  99     *  also support multiple monitors where each display can have its  
 100     *  its own unique data. In this case each display could be  
 101     *  represented by a separate framebuffer device thus a separate 
 102     *  struct fb_info. Now the struct xxx_par represents the graphics
 103     *  hardware state thus only one exist per card. In this case the 
 104     *  struct xxx_par for each graphics card would be shared between 
 105     *  every struct fb_info that represents a framebuffer on that card. 
 106     *  This allows when one display changes it video resolution (info->var) 
 107     *  the other displays know instantly. Each display can always be
 108     *  aware of the entire hardware state that affects it because they share
 109     *  the same xxx_par struct. The other side of the coin is multiple
 110     *  graphics cards that pass data around until it is finally displayed
 111     *  on one monitor. Such examples are the voodoo 1 cards and high end
 112     *  NUMA graphics servers. For this case we have a bunch of pars, each
 113     *  one that represents a graphics state, that belong to one struct 
 114     *  fb_info. Their you would want to have *par point to a array of device
 115     *  states and have each struct fb_ops function deal with all those 
 116     *  states. I hope this covers every possible hardware design. If not
 117     *  feel free to send your ideas at jsimmons@users.sf.net 
 118     */
 119
 120    /*
 121     *  If your driver supports multiple boards or it supports multiple 
 122     *  framebuffers, you should make these arrays, or allocate them 
 123     *  dynamically using framebuffer_alloc() and free them with
 124     *  framebuffer_release().
 125     */ 
 126static struct fb_info info;
 127
 128    /* 
 129     * Each one represents the state of the hardware. Most hardware have
 130     * just one hardware state. These here represent the default state(s). 
 131     */
 132static struct xxx_par __initdata current_par;
 133
 134int xxxfb_init(void);
 135
 136/**
 137 *      xxxfb_open - Optional function. Called when the framebuffer is
 138 *                   first accessed.
 139 *      @info: frame buffer structure that represents a single frame buffer
 140 *      @user: tell us if the userland (value=1) or the console is accessing
 141 *             the framebuffer. 
 142 *
 143 *      This function is the first function called in the framebuffer api.
 144 *      Usually you don't need to provide this function. The case where it 
 145 *      is used is to change from a text mode hardware state to a graphics
 146 *      mode state. 
 147 *
 148 *      Returns negative errno on error, or zero on success.
 149 */
 150static int xxxfb_open(struct fb_info *info, int user)
 151{
 152    return 0;
 153}
 154
 155/**
 156 *      xxxfb_release - Optional function. Called when the framebuffer 
 157 *                      device is closed. 
 158 *      @info: frame buffer structure that represents a single frame buffer
 159 *      @user: tell us if the userland (value=1) or the console is accessing
 160 *             the framebuffer. 
 161 *      
 162 *      Thus function is called when we close /dev/fb or the framebuffer 
 163 *      console system is released. Usually you don't need this function.
 164 *      The case where it is usually used is to go from a graphics state
 165 *      to a text mode state.
 166 *
 167 *      Returns negative errno on error, or zero on success.
 168 */
 169static int xxxfb_release(struct fb_info *info, int user)
 170{
 171    return 0;
 172}
 173
 174/**
 175 *      xxxfb_check_var - Optional function. Validates a var passed in. 
 176 *      @var: frame buffer variable screen structure
 177 *      @info: frame buffer structure that represents a single frame buffer 
 178 *
 179 *      Checks to see if the hardware supports the state requested by
 180 *      var passed in. This function does not alter the hardware state!!! 
 181 *      This means the data stored in struct fb_info and struct xxx_par do 
 182 *      not change. This includes the var inside of struct fb_info. 
 183 *      Do NOT change these. This function can be called on its own if we
 184 *      intent to only test a mode and not actually set it. The stuff in 
 185 *      modedb.c is a example of this. If the var passed in is slightly 
 186 *      off by what the hardware can support then we alter the var PASSED in
 187 *      to what we can do.
 188 *
 189 *      For values that are off, this function must round them _up_ to the
 190 *      next value that is supported by the hardware.  If the value is
 191 *      greater than the highest value supported by the hardware, then this
 192 *      function must return -EINVAL.
 193 *
 194 *      Exception to the above rule:  Some drivers have a fixed mode, ie,
 195 *      the hardware is already set at boot up, and cannot be changed.  In
 196 *      this case, it is more acceptable that this function just return
 197 *      a copy of the currently working var (info->var). Better is to not
 198 *      implement this function, as the upper layer will do the copying
 199 *      of the current var for you.
 200 *
 201 *      Note:  This is the only function where the contents of var can be
 202 *      freely adjusted after the driver has been registered. If you find
 203 *      that you have code outside of this function that alters the content
 204 *      of var, then you are doing something wrong.  Note also that the
 205 *      contents of info->var must be left untouched at all times after
 206 *      driver registration.
 207 *
 208 *      Returns negative errno on error, or zero on success.
 209 */
 210static int xxxfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
 211{
 212    /* ... */
 213    return 0;           
 214}
 215
 216/**
 217 *      xxxfb_set_par - Optional function. Alters the hardware state.
 218 *      @info: frame buffer structure that represents a single frame buffer
 219 *
 220 *      Using the fb_var_screeninfo in fb_info we set the resolution of the
 221 *      this particular framebuffer. This function alters the par AND the
 222 *      fb_fix_screeninfo stored in fb_info. It doesn't not alter var in 
 223 *      fb_info since we are using that data. This means we depend on the
 224 *      data in var inside fb_info to be supported by the hardware. 
 225 *
 226 *      This function is also used to recover/restore the hardware to a
 227 *      known working state.
 228 *
 229 *      xxxfb_check_var is always called before xxxfb_set_par to ensure that
 230 *      the contents of var is always valid.
 231 *
 232 *      Again if you can't change the resolution you don't need this function.
 233 *
 234 *      However, even if your hardware does not support mode changing,
 235 *      a set_par might be needed to at least initialize the hardware to
 236 *      a known working state, especially if it came back from another
 237 *      process that also modifies the same hardware, such as X.
 238 *
 239 *      If this is the case, a combination such as the following should work:
 240 *
 241 *      static int xxxfb_check_var(struct fb_var_screeninfo *var,
 242 *                                struct fb_info *info)
 243 *      {
 244 *              *var = info->var;
 245 *              return 0;
 246 *      }
 247 *
 248 *      static int xxxfb_set_par(struct fb_info *info)
 249 *      {
 250 *              init your hardware here
 251 *      }
 252 *
 253 *      Returns negative errno on error, or zero on success.
 254 */
 255static int xxxfb_set_par(struct fb_info *info)
 256{
 257    struct xxx_par *par = info->par;
 258    /* ... */
 259    return 0;   
 260}
 261
 262/**
 263 *      xxxfb_setcolreg - Optional function. Sets a color register.
 264 *      @regno: Which register in the CLUT we are programming 
 265 *      @red: The red value which can be up to 16 bits wide 
 266 *      @green: The green value which can be up to 16 bits wide 
 267 *      @blue:  The blue value which can be up to 16 bits wide.
 268 *      @transp: If supported, the alpha value which can be up to 16 bits wide.
 269 *      @info: frame buffer info structure
 270 * 
 271 *      Set a single color register. The values supplied have a 16 bit
 272 *      magnitude which needs to be scaled in this function for the hardware. 
 273 *      Things to take into consideration are how many color registers, if
 274 *      any, are supported with the current color visual. With truecolor mode
 275 *      no color palettes are supported. Here a pseudo palette is created
 276 *      which we store the value in pseudo_palette in struct fb_info. For
 277 *      pseudocolor mode we have a limited color palette. To deal with this
 278 *      we can program what color is displayed for a particular pixel value.
 279 *      DirectColor is similar in that we can program each color field. If
 280 *      we have a static colormap we don't need to implement this function. 
 281 * 
 282 *      Returns negative errno on error, or zero on success.
 283 */
 284static int xxxfb_setcolreg(unsigned regno, unsigned red, unsigned green,
 285                           unsigned blue, unsigned transp,
 286                           struct fb_info *info)
 287{
 288    if (regno >= 256)  /* no. of hw registers */
 289       return -EINVAL;
 290    /*
 291     * Program hardware... do anything you want with transp
 292     */
 293
 294    /* grayscale works only partially under directcolor */
 295    if (info->var.grayscale) {
 296       /* grayscale = 0.30*R + 0.59*G + 0.11*B */
 297       red = green = blue = (red * 77 + green * 151 + blue * 28) >> 8;
 298    }
 299
 300    /* Directcolor:
 301     *   var->{color}.offset contains start of bitfield
 302     *   var->{color}.length contains length of bitfield
 303     *   {hardwarespecific} contains width of DAC
 304     *   pseudo_palette[X] is programmed to (X << red.offset) |
 305     *                                      (X << green.offset) |
 306     *                                      (X << blue.offset)
 307     *   RAMDAC[X] is programmed to (red, green, blue)
 308     *   color depth = SUM(var->{color}.length)
 309     *
 310     * Pseudocolor:
 311     *    var->{color}.offset is 0 unless the palette index takes less than
 312     *                        bits_per_pixel bits and is stored in the upper
 313     *                        bits of the pixel value
 314     *    var->{color}.length is set so that 1 << length is the number of
 315     *                        available palette entries
 316     *    pseudo_palette is not used
 317     *    RAMDAC[X] is programmed to (red, green, blue)
 318     *    color depth = var->{color}.length
 319     *
 320     * Static pseudocolor:
 321     *    same as Pseudocolor, but the RAMDAC is not programmed (read-only)
 322     *
 323     * Mono01/Mono10:
 324     *    Has only 2 values, black on white or white on black (fg on bg),
 325     *    var->{color}.offset is 0
 326     *    white = (1 << var->{color}.length) - 1, black = 0
 327     *    pseudo_palette is not used
 328     *    RAMDAC does not exist
 329     *    color depth is always 2
 330     *
 331     * Truecolor:
 332     *    does not use RAMDAC (usually has 3 of them).
 333     *    var->{color}.offset contains start of bitfield
 334     *    var->{color}.length contains length of bitfield
 335     *    pseudo_palette is programmed to (red << red.offset) |
 336     *                                    (green << green.offset) |
 337     *                                    (blue << blue.offset) |
 338     *                                    (transp << transp.offset)
 339     *    RAMDAC does not exist
 340     *    color depth = SUM(var->{color}.length})
 341     *
 342     *  The color depth is used by fbcon for choosing the logo and also
 343     *  for color palette transformation if color depth < 4
 344     *
 345     *  As can be seen from the above, the field bits_per_pixel is _NOT_
 346     *  a criteria for describing the color visual.
 347     *
 348     *  A common mistake is assuming that bits_per_pixel <= 8 is pseudocolor,
 349     *  and higher than that, true/directcolor.  This is incorrect, one needs
 350     *  to look at the fix->visual.
 351     *
 352     *  Another common mistake is using bits_per_pixel to calculate the color
 353     *  depth.  The bits_per_pixel field does not directly translate to color
 354     *  depth. You have to compute for the color depth (using the color
 355     *  bitfields) and fix->visual as seen above.
 356     */
 357
 358    /*
 359     * This is the point where the color is converted to something that
 360     * is acceptable by the hardware.
 361     */
 362#define CNVT_TOHW(val,width) ((((val)<<(width))+0x7FFF-(val))>>16)
 363    red = CNVT_TOHW(red, info->var.red.length);
 364    green = CNVT_TOHW(green, info->var.green.length);
 365    blue = CNVT_TOHW(blue, info->var.blue.length);
 366    transp = CNVT_TOHW(transp, info->var.transp.length);
 367#undef CNVT_TOHW
 368    /*
 369     * This is the point where the function feeds the color to the hardware
 370     * palette after converting the colors to something acceptable by
 371     * the hardware. Note, only FB_VISUAL_DIRECTCOLOR and
 372     * FB_VISUAL_PSEUDOCOLOR visuals need to write to the hardware palette.
 373     * If you have code that writes to the hardware CLUT, and it's not
 374     * any of the above visuals, then you are doing something wrong.
 375     */
 376    if (info->fix.visual == FB_VISUAL_DIRECTCOLOR ||
 377        info->fix.visual == FB_VISUAL_TRUECOLOR)
 378            write_{red|green|blue|transp}_to_clut();
 379
 380    /* This is the point were you need to fill up the contents of
 381     * info->pseudo_palette. This structure is used _only_ by fbcon, thus
 382     * it only contains 16 entries to match the number of colors supported
 383     * by the console. The pseudo_palette is used only if the visual is
 384     * in directcolor or truecolor mode.  With other visuals, the
 385     * pseudo_palette is not used. (This might change in the future.)
 386     *
 387     * The contents of the pseudo_palette is in raw pixel format.  Ie, each
 388     * entry can be written directly to the framebuffer without any conversion.
 389     * The pseudo_palette is (void *).  However, if using the generic
 390     * drawing functions (cfb_imageblit, cfb_fillrect), the pseudo_palette
 391     * must be casted to (u32 *) _regardless_ of the bits per pixel. If the
 392     * driver is using its own drawing functions, then it can use whatever
 393     * size it wants.
 394     */
 395    if (info->fix.visual == FB_VISUAL_TRUECOLOR ||
 396        info->fix.visual == FB_VISUAL_DIRECTCOLOR) {
 397            u32 v;
 398
 399            if (regno >= 16)
 400                    return -EINVAL;
 401
 402            v = (red << info->var.red.offset) |
 403                    (green << info->var.green.offset) |
 404                    (blue << info->var.blue.offset) |
 405                    (transp << info->var.transp.offset);
 406
 407            ((u32*)(info->pseudo_palette))[regno] = v;
 408    }
 409
 410    /* ... */
 411    return 0;
 412}
 413
 414/**
 415 *      xxxfb_pan_display - NOT a required function. Pans the display.
 416 *      @var: frame buffer variable screen structure
 417 *      @info: frame buffer structure that represents a single frame buffer
 418 *
 419 *      Pan (or wrap, depending on the `vmode' field) the display using the
 420 *      `xoffset' and `yoffset' fields of the `var' structure.
 421 *      If the values don't fit, return -EINVAL.
 422 *
 423 *      Returns negative errno on error, or zero on success.
 424 */
 425static int xxxfb_pan_display(struct fb_var_screeninfo *var,
 426                             struct fb_info *info)
 427{
 428    /*
 429     * If your hardware does not support panning, _do_ _not_ implement this
 430     * function. Creating a dummy function will just confuse user apps.
 431     */
 432
 433    /*
 434     * Note that even if this function is fully functional, a setting of
 435     * 0 in both xpanstep and ypanstep means that this function will never
 436     * get called.
 437     */
 438
 439    /* ... */
 440    return 0;
 441}
 442
 443/**
 444 *      xxxfb_blank - NOT a required function. Blanks the display.
 445 *      @blank_mode: the blank mode we want. 
 446 *      @info: frame buffer structure that represents a single frame buffer
 447 *
 448 *      Blank the screen if blank_mode != FB_BLANK_UNBLANK, else unblank.
 449 *      Return 0 if blanking succeeded, != 0 if un-/blanking failed due to
 450 *      e.g. a video mode which doesn't support it.
 451 *
 452 *      Implements VESA suspend and powerdown modes on hardware that supports
 453 *      disabling hsync/vsync:
 454 *
 455 *      FB_BLANK_NORMAL = display is blanked, syncs are on.
 456 *      FB_BLANK_HSYNC_SUSPEND = hsync off
 457 *      FB_BLANK_VSYNC_SUSPEND = vsync off
 458 *      FB_BLANK_POWERDOWN =  hsync and vsync off
 459 *
 460 *      If implementing this function, at least support FB_BLANK_UNBLANK.
 461 *      Return !0 for any modes that are unimplemented.
 462 *
 463 */
 464static int xxxfb_blank(int blank_mode, struct fb_info *info)
 465{
 466    /* ... */
 467    return 0;
 468}
 469
 470/* ------------ Accelerated Functions --------------------- */
 471
 472/*
 473 * We provide our own functions if we have hardware acceleration
 474 * or non packed pixel format layouts. If we have no hardware 
 475 * acceleration, we can use a generic unaccelerated function. If using
 476 * a pack pixel format just use the functions in cfb_*.c. Each file 
 477 * has one of the three different accel functions we support.
 478 */
 479
 480/**
 481 *      xxxfb_fillrect - REQUIRED function. Can use generic routines if 
 482 *                       non acclerated hardware and packed pixel based.
 483 *                       Draws a rectangle on the screen.               
 484 *
 485 *      @info: frame buffer structure that represents a single frame buffer
 486 *      @region: The structure representing the rectangular region we 
 487 *               wish to draw to.
 488 *
 489 *      This drawing operation places/removes a retangle on the screen 
 490 *      depending on the rastering operation with the value of color which
 491 *      is in the current color depth format.
 492 */
 493void xxxfb_fillrect(struct fb_info *p, const struct fb_fillrect *region)
 494{
 495/*      Meaning of struct fb_fillrect
 496 *
 497 *      @dx: The x and y corrdinates of the upper left hand corner of the 
 498 *      @dy: area we want to draw to. 
 499 *      @width: How wide the rectangle is we want to draw.
 500 *      @height: How tall the rectangle is we want to draw.
 501 *      @color: The color to fill in the rectangle with. 
 502 *      @rop: The raster operation. We can draw the rectangle with a COPY
 503 *            of XOR which provides erasing effect. 
 504 */
 505}
 506
 507/**
 508 *      xxxfb_copyarea - REQUIRED function. Can use generic routines if
 509 *                       non acclerated hardware and packed pixel based.
 510 *                       Copies one area of the screen to another area.
 511 *
 512 *      @info: frame buffer structure that represents a single frame buffer
 513 *      @area: Structure providing the data to copy the framebuffer contents
 514 *             from one region to another.
 515 *
 516 *      This drawing operation copies a rectangular area from one area of the
 517 *      screen to another area.
 518 */
 519void xxxfb_copyarea(struct fb_info *p, const struct fb_copyarea *area) 
 520{
 521/*
 522 *      @dx: The x and y coordinates of the upper left hand corner of the
 523 *      @dy: destination area on the screen.
 524 *      @width: How wide the rectangle is we want to copy.
 525 *      @height: How tall the rectangle is we want to copy.
 526 *      @sx: The x and y coordinates of the upper left hand corner of the
 527 *      @sy: source area on the screen.
 528 */
 529}
 530
 531
 532/**
 533 *      xxxfb_imageblit - REQUIRED function. Can use generic routines if
 534 *                        non acclerated hardware and packed pixel based.
 535 *                        Copies a image from system memory to the screen. 
 536 *
 537 *      @info: frame buffer structure that represents a single frame buffer
 538 *      @image: structure defining the image.
 539 *
 540 *      This drawing operation draws a image on the screen. It can be a 
 541 *      mono image (needed for font handling) or a color image (needed for
 542 *      tux). 
 543 */
 544void xxxfb_imageblit(struct fb_info *p, const struct fb_image *image) 
 545{
 546/*
 547 *      @dx: The x and y coordinates of the upper left hand corner of the
 548 *      @dy: destination area to place the image on the screen.
 549 *      @width: How wide the image is we want to copy.
 550 *      @height: How tall the image is we want to copy.
 551 *      @fg_color: For mono bitmap images this is color data for     
 552 *      @bg_color: the foreground and background of the image to
 553 *                 write directly to the frmaebuffer.
 554 *      @depth: How many bits represent a single pixel for this image.
 555 *      @data: The actual data used to construct the image on the display.
 556 *      @cmap: The colormap used for color images.   
 557 */
 558
 559/*
 560 * The generic function, cfb_imageblit, expects that the bitmap scanlines are
 561 * padded to the next byte.  Most hardware accelerators may require padding to
 562 * the next u16 or the next u32.  If that is the case, the driver can specify
 563 * this by setting info->pixmap.scan_align = 2 or 4.  See a more
 564 * comprehensive description of the pixmap below.
 565 */
 566}
 567
 568/**
 569 *      xxxfb_cursor -  OPTIONAL. If your hardware lacks support
 570 *                      for a cursor, leave this field NULL.
 571 *
 572 *      @info: frame buffer structure that represents a single frame buffer
 573 *      @cursor: structure defining the cursor to draw.
 574 *
 575 *      This operation is used to set or alter the properities of the
 576 *      cursor.
 577 *
 578 *      Returns negative errno on error, or zero on success.
 579 */
 580int xxxfb_cursor(struct fb_info *info, struct fb_cursor *cursor)
 581{
 582/*
 583 *      @set:   Which fields we are altering in struct fb_cursor 
 584 *      @enable: Disable or enable the cursor 
 585 *      @rop:   The bit operation we want to do. 
 586 *      @mask:  This is the cursor mask bitmap. 
 587 *      @dest:  A image of the area we are going to display the cursor.
 588 *              Used internally by the driver.   
 589 *      @hot:   The hot spot. 
 590 *      @image: The actual data for the cursor image.
 591 *
 592 *      NOTES ON FLAGS (cursor->set):
 593 *
 594 *      FB_CUR_SETIMAGE - the cursor image has changed (cursor->image.data)
 595 *      FB_CUR_SETPOS   - the cursor position has changed (cursor->image.dx|dy)
 596 *      FB_CUR_SETHOT   - the cursor hot spot has changed (cursor->hot.dx|dy)
 597 *      FB_CUR_SETCMAP  - the cursor colors has changed (cursor->fg_color|bg_color)
 598 *      FB_CUR_SETSHAPE - the cursor bitmask has changed (cursor->mask)
 599 *      FB_CUR_SETSIZE  - the cursor size has changed (cursor->width|height)
 600 *      FB_CUR_SETALL   - everything has changed
 601 *
 602 *      NOTES ON ROPs (cursor->rop, Raster Operation)
 603 *
 604 *      ROP_XOR         - cursor->image.data XOR cursor->mask
 605 *      ROP_COPY        - curosr->image.data AND cursor->mask
 606 *
 607 *      OTHER NOTES:
 608 *
 609 *      - fbcon only supports a 2-color cursor (cursor->image.depth = 1)
 610 *      - The fb_cursor structure, @cursor, _will_ always contain valid
 611 *        fields, whether any particular bitfields in cursor->set is set
 612 *        or not.
 613 */
 614}
 615
 616/**
 617 *      xxxfb_rotate -  NOT a required function. If your hardware
 618 *                      supports rotation the whole screen then 
 619 *                      you would provide a hook for this. 
 620 *
 621 *      @info: frame buffer structure that represents a single frame buffer
 622 *      @angle: The angle we rotate the screen.   
 623 *
 624 *      This operation is used to set or alter the properities of the
 625 *      cursor.
 626 */
 627void xxxfb_rotate(struct fb_info *info, int angle)
 628{
 629/* Will be deprecated */
 630}
 631
 632/**
 633 *      xxxfb_sync - NOT a required function. Normally the accel engine 
 634 *                   for a graphics card take a specific amount of time.
 635 *                   Often we have to wait for the accelerator to finish
 636 *                   its operation before we can write to the framebuffer
 637 *                   so we can have consistent display output. 
 638 *
 639 *      @info: frame buffer structure that represents a single frame buffer
 640 *
 641 *      If the driver has implemented its own hardware-based drawing function,
 642 *      implementing this function is highly recommended.
 643 */
 644int xxxfb_sync(struct fb_info *info)
 645{
 646        return 0;
 647}
 648
 649    /*
 650     *  Frame buffer operations
 651     */
 652
 653static struct fb_ops xxxfb_ops = {
 654        .owner          = THIS_MODULE,
 655        .fb_open        = xxxfb_open,
 656        .fb_read        = xxxfb_read,
 657        .fb_write       = xxxfb_write,
 658        .fb_release     = xxxfb_release,
 659        .fb_check_var   = xxxfb_check_var,
 660        .fb_set_par     = xxxfb_set_par,
 661        .fb_setcolreg   = xxxfb_setcolreg,
 662        .fb_blank       = xxxfb_blank,
 663        .fb_pan_display = xxxfb_pan_display,
 664        .fb_fillrect    = xxxfb_fillrect,       /* Needed !!! */
 665        .fb_copyarea    = xxxfb_copyarea,       /* Needed !!! */
 666        .fb_imageblit   = xxxfb_imageblit,      /* Needed !!! */
 667        .fb_cursor      = xxxfb_cursor,         /* Optional !!! */
 668        .fb_rotate      = xxxfb_rotate,
 669        .fb_sync        = xxxfb_sync,
 670        .fb_ioctl       = xxxfb_ioctl,
 671        .fb_mmap        = xxxfb_mmap,
 672};
 673
 674/* ------------------------------------------------------------------------- */
 675
 676    /*
 677     *  Initialization
 678     */
 679
 680/* static int __init xxfb_probe (struct platform_device *pdev) -- for platform devs */
 681static int xxxfb_probe(struct pci_dev *dev, const struct pci_device_id *ent)
 682{
 683    struct fb_info *info;
 684    struct xxx_par *par;
 685    struct device *device = &dev->dev; /* or &pdev->dev */
 686    int cmap_len, retval;       
 687   
 688    /*
 689     * Dynamically allocate info and par
 690     */
 691    info = framebuffer_alloc(sizeof(struct xxx_par), device);
 692
 693    if (!info) {
 694            /* goto error path */
 695    }
 696
 697    par = info->par;
 698
 699    /* 
 700     * Here we set the screen_base to the virtual memory address
 701     * for the framebuffer. Usually we obtain the resource address
 702     * from the bus layer and then translate it to virtual memory
 703     * space via ioremap. Consult ioport.h. 
 704     */
 705    info->screen_base = framebuffer_virtual_memory;
 706    info->fbops = &xxxfb_ops;
 707    info->fix = xxxfb_fix;
 708    info->pseudo_palette = pseudo_palette; /* The pseudopalette is an
 709                                            * 16-member array
 710                                            */
 711    /*
 712     * Set up flags to indicate what sort of acceleration your
 713     * driver can provide (pan/wrap/copyarea/etc.) and whether it
 714     * is a module -- see FBINFO_* in include/linux/fb.h
 715     *
 716     * If your hardware can support any of the hardware accelerated functions
 717     * fbcon performance will improve if info->flags is set properly.
 718     *
 719     * FBINFO_HWACCEL_COPYAREA - hardware moves
 720     * FBINFO_HWACCEL_FILLRECT - hardware fills
 721     * FBINFO_HWACCEL_IMAGEBLIT - hardware mono->color expansion
 722     * FBINFO_HWACCEL_YPAN - hardware can pan display in y-axis
 723     * FBINFO_HWACCEL_YWRAP - hardware can wrap display in y-axis
 724     * FBINFO_HWACCEL_DISABLED - supports hardware accels, but disabled
 725     * FBINFO_READS_FAST - if set, prefer moves over mono->color expansion
 726     * FBINFO_MISC_TILEBLITTING - hardware can do tile blits
 727     *
 728     * NOTE: These are for fbcon use only.
 729     */
 730    info->flags = FBINFO_DEFAULT;
 731
 732/********************* This stage is optional ******************************/
 733     /*
 734     * The struct pixmap is a scratch pad for the drawing functions. This
 735     * is where the monochrome bitmap is constructed by the higher layers
 736     * and then passed to the accelerator.  For drivers that uses
 737     * cfb_imageblit, you can skip this part.  For those that have a more
 738     * rigorous requirement, this stage is needed
 739     */
 740
 741    /* PIXMAP_SIZE should be small enough to optimize drawing, but not
 742     * large enough that memory is wasted.  A safe size is
 743     * (max_xres * max_font_height/8). max_xres is driver dependent,
 744     * max_font_height is 32.
 745     */
 746    info->pixmap.addr = kmalloc(PIXMAP_SIZE, GFP_KERNEL);
 747    if (!info->pixmap.addr) {
 748            /* goto error */
 749    }
 750
 751    info->pixmap.size = PIXMAP_SIZE;
 752
 753    /*
 754     * FB_PIXMAP_SYSTEM - memory is in system ram
 755     * FB_PIXMAP_IO     - memory is iomapped
 756     * FB_PIXMAP_SYNC   - if set, will call fb_sync() per access to pixmap,
 757     *                    usually if FB_PIXMAP_IO is set.
 758     *
 759     * Currently, FB_PIXMAP_IO is unimplemented.
 760     */
 761    info->pixmap.flags = FB_PIXMAP_SYSTEM;
 762
 763    /*
 764     * scan_align is the number of padding for each scanline.  It is in bytes.
 765     * Thus for accelerators that need padding to the next u32, put 4 here.
 766     */
 767    info->pixmap.scan_align = 4;
 768
 769    /*
 770     * buf_align is the amount to be padded for the buffer. For example,
 771     * the i810fb needs a scan_align of 2 but expects it to be fed with
 772     * dwords, so a buf_align = 4 is required.
 773     */
 774    info->pixmap.buf_align = 4;
 775
 776    /* access_align is how many bits can be accessed from the framebuffer
 777     * ie. some epson cards allow 16-bit access only.  Most drivers will
 778     * be safe with u32 here.
 779     *
 780     * NOTE: This field is currently unused.
 781     */
 782    info->pixmap.access_align = 32;
 783/***************************** End optional stage ***************************/
 784
 785    /*
 786     * This should give a reasonable default video mode. The following is
 787     * done when we can set a video mode. 
 788     */
 789    if (!mode_option)
 790        mode_option = "640x480@60";             
 791
 792    retval = fb_find_mode(&info->var, info, mode_option, NULL, 0, NULL, 8);
 793  
 794    if (!retval || retval == 4)
 795        return -EINVAL;                 
 796
 797    /* This has to be done! */
 798    if (fb_alloc_cmap(&info->cmap, cmap_len, 0))
 799        return -ENOMEM;
 800        
 801    /* 
 802     * The following is done in the case of having hardware with a static 
 803     * mode. If we are setting the mode ourselves we don't call this. 
 804     */ 
 805    info->var = xxxfb_var;
 806
 807    /*
 808     * For drivers that can...
 809     */
 810    xxxfb_check_var(&info->var, info);
 811
 812    /*
 813     * Does a call to fb_set_par() before register_framebuffer needed?  This
 814     * will depend on you and the hardware.  If you are sure that your driver
 815     * is the only device in the system, a call to fb_set_par() is safe.
 816     *
 817     * Hardware in x86 systems has a VGA core.  Calling set_par() at this
 818     * point will corrupt the VGA console, so it might be safer to skip a
 819     * call to set_par here and just allow fbcon to do it for you.
 820     */
 821    /* xxxfb_set_par(info); */
 822
 823    if (register_framebuffer(info) < 0) {
 824        fb_dealloc_cmap(&info->cmap);
 825        return -EINVAL;
 826    }
 827    printk(KERN_INFO "fb%d: %s frame buffer device\n", info->node,
 828           info->fix.id);
 829    pci_set_drvdata(dev, info); /* or platform_set_drvdata(pdev, info) */
 830    return 0;
 831}
 832
 833    /*
 834     *  Cleanup
 835     */
 836/* static void xxxfb_remove(struct platform_device *pdev) */
 837static void xxxfb_remove(struct pci_dev *dev)
 838{
 839        struct fb_info *info = pci_get_drvdata(dev);
 840        /* or platform_get_drvdata(pdev); */
 841
 842        if (info) {
 843                unregister_framebuffer(info);
 844                fb_dealloc_cmap(&info->cmap);
 845                /* ... */
 846                framebuffer_release(info);
 847        }
 848}
 849
 850#ifdef CONFIG_PCI
 851#ifdef CONFIG_PM
 852/**
 853 *      xxxfb_suspend - Optional but recommended function. Suspend the device.
 854 *      @dev: PCI device
 855 *      @msg: the suspend event code.
 856 *
 857 *      See Documentation/power/devices.txt for more information
 858 */
 859static int xxxfb_suspend(struct pci_dev *dev, pm_message_t msg)
 860{
 861        struct fb_info *info = pci_get_drvdata(dev);
 862        struct xxxfb_par *par = info->par;
 863
 864        /* suspend here */
 865        return 0;
 866}
 867
 868/**
 869 *      xxxfb_resume - Optional but recommended function. Resume the device.
 870 *      @dev: PCI device
 871 *
 872 *      See Documentation/power/devices.txt for more information
 873 */
 874static int xxxfb_resume(struct pci_dev *dev)
 875{
 876        struct fb_info *info = pci_get_drvdata(dev);
 877        struct xxxfb_par *par = info->par;
 878
 879        /* resume here */
 880        return 0;
 881}
 882#else
 883#define xxxfb_suspend NULL
 884#define xxxfb_resume NULL
 885#endif /* CONFIG_PM */
 886
 887static struct pci_device_id xxxfb_id_table[] = {
 888        { PCI_VENDOR_ID_XXX, PCI_DEVICE_ID_XXX,
 889          PCI_ANY_ID, PCI_ANY_ID, PCI_BASE_CLASS_DISPLAY << 16,
 890          PCI_CLASS_MASK, 0 },
 891        { 0, }
 892};
 893
 894/* For PCI drivers */
 895static struct pci_driver xxxfb_driver = {
 896        .name =         "xxxfb",
 897        .id_table =     xxxfb_id_table,
 898        .probe =        xxxfb_probe,
 899        .remove =       xxxfb_remove,
 900        .suspend =      xxxfb_suspend, /* optional but recommended */
 901        .resume =       xxxfb_resume,  /* optional but recommended */
 902};
 903
 904MODULE_DEVICE_TABLE(pci, xxxfb_id_table);
 905
 906int __init xxxfb_init(void)
 907{
 908        /*
 909         *  For kernel boot options (in 'video=xxxfb:<options>' format)
 910         */
 911#ifndef MODULE
 912        char *option = NULL;
 913
 914        if (fb_get_options("xxxfb", &option))
 915                return -ENODEV;
 916        xxxfb_setup(option);
 917#endif
 918
 919        return pci_register_driver(&xxxfb_driver);
 920}
 921
 922static void __exit xxxfb_exit(void)
 923{
 924        pci_unregister_driver(&xxxfb_driver);
 925}
 926#else /* non PCI, platform drivers */
 927#include <linux/platform_device.h>
 928/* for platform devices */
 929
 930#ifdef CONFIG_PM
 931/**
 932 *      xxxfb_suspend - Optional but recommended function. Suspend the device.
 933 *      @dev: platform device
 934 *      @msg: the suspend event code.
 935 *
 936 *      See Documentation/power/devices.txt for more information
 937 */
 938static int xxxfb_suspend(struct platform_device *dev, pm_message_t msg)
 939{
 940        struct fb_info *info = platform_get_drvdata(dev);
 941        struct xxxfb_par *par = info->par;
 942
 943        /* suspend here */
 944        return 0;
 945}
 946
 947/**
 948 *      xxxfb_resume - Optional but recommended function. Resume the device.
 949 *      @dev: platform device
 950 *
 951 *      See Documentation/power/devices.txt for more information
 952 */
 953static int xxxfb_resume(struct platform_dev *dev)
 954{
 955        struct fb_info *info = platform_get_drvdata(dev);
 956        struct xxxfb_par *par = info->par;
 957
 958        /* resume here */
 959        return 0;
 960}
 961#else
 962#define xxxfb_suspend NULL
 963#define xxxfb_resume NULL
 964#endif /* CONFIG_PM */
 965
 966static struct platform_device_driver xxxfb_driver = {
 967        .probe = xxxfb_probe,
 968        .remove = xxxfb_remove,
 969        .suspend = xxxfb_suspend, /* optional but recommended */
 970        .resume = xxxfb_resume,   /* optional but recommended */
 971        .driver = {
 972                .name = "xxxfb",
 973        },
 974};
 975
 976static struct platform_device *xxxfb_device;
 977
 978#ifndef MODULE
 979    /*
 980     *  Setup
 981     */
 982
 983/*
 984 * Only necessary if your driver takes special options,
 985 * otherwise we fall back on the generic fb_setup().
 986 */
 987int __init xxxfb_setup(char *options)
 988{
 989    /* Parse user specified options (`video=xxxfb:') */
 990}
 991#endif /* MODULE */
 992
 993static int __init xxxfb_init(void)
 994{
 995        int ret;
 996        /*
 997         *  For kernel boot options (in 'video=xxxfb:<options>' format)
 998         */
 999#ifndef MODULE
1000        char *option = NULL;
1001
1002        if (fb_get_options("xxxfb", &option))
1003                return -ENODEV;
1004        xxxfb_setup(option);
1005#endif
1006        ret = platform_driver_register(&xxxfb_driver);
1007
1008        if (!ret) {
1009                xxxfb_device = platform_device_register_simple("xxxfb", 0,
1010                                                                NULL, 0);
1011
1012                if (IS_ERR(xxxfb_device)) {
1013                        platform_driver_unregister(&xxxfb_driver);
1014                        ret = PTR_ERR(xxxfb_device);
1015                }
1016        }
1017
1018        return ret;
1019}
1020
1021static void __exit xxxfb_exit(void)
1022{
1023        platform_device_unregister(xxxfb_device);
1024        platform_driver_unregister(&xxxfb_driver);
1025}
1026#endif /* CONFIG_PCI */
1027
1028/* ------------------------------------------------------------------------- */
1029
1030
1031    /*
1032     *  Modularization
1033     */
1034
1035module_init(xxxfb_init);
1036module_exit(xxxfb_exit);
1037
1038MODULE_LICENSE("GPL");
1039
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