| /* | 
 |  * linux/drivers/video/skeletonfb.c -- Skeleton for a frame buffer device | 
 |  * | 
 |  *  Modified to new api Jan 2001 by James Simmons (jsimmons@transvirtual.com) | 
 |  * | 
 |  *  Created 28 Dec 1997 by Geert Uytterhoeven | 
 |  * | 
 |  * | 
 |  *  I have started rewriting this driver as a example of the upcoming new API | 
 |  *  The primary goal is to remove the console code from fbdev and place it | 
 |  *  into fbcon.c. This reduces the code and makes writing a new fbdev driver | 
 |  *  easy since the author doesn't need to worry about console internals. It | 
 |  *  also allows the ability to run fbdev without a console/tty system on top  | 
 |  *  of it.  | 
 |  * | 
 |  *  First the roles of struct fb_info and struct display have changed. Struct | 
 |  *  display will go away. The way the the new framebuffer console code will | 
 |  *  work is that it will act to translate data about the tty/console in  | 
 |  *  struct vc_data to data in a device independent way in struct fb_info. Then | 
 |  *  various functions in struct fb_ops will be called to store the device  | 
 |  *  dependent state in the par field in struct fb_info and to change the  | 
 |  *  hardware to that state. This allows a very clean separation of the fbdev | 
 |  *  layer from the console layer. It also allows one to use fbdev on its own | 
 |  *  which is a bounus for embedded devices. The reason this approach works is   | 
 |  *  for each framebuffer device when used as a tty/console device is allocated | 
 |  *  a set of virtual terminals to it. Only one virtual terminal can be active  | 
 |  *  per framebuffer device. We already have all the data we need in struct  | 
 |  *  vc_data so why store a bunch of colormaps and other fbdev specific data | 
 |  *  per virtual terminal.  | 
 |  * | 
 |  *  As you can see doing this makes the con parameter pretty much useless | 
 |  *  for struct fb_ops functions, as it should be. Also having struct   | 
 |  *  fb_var_screeninfo and other data in fb_info pretty much eliminates the  | 
 |  *  need for get_fix and get_var. Once all drivers use the fix, var, and cmap | 
 |  *  fbcon can be written around these fields. This will also eliminate the | 
 |  *  need to regenerate struct fb_var_screeninfo, struct fb_fix_screeninfo | 
 |  *  struct fb_cmap every time get_var, get_fix, get_cmap functions are called | 
 |  *  as many drivers do now.  | 
 |  * | 
 |  *  This file is subject to the terms and conditions of the GNU General Public | 
 |  *  License. See the file COPYING in the main directory of this archive for | 
 |  *  more details. | 
 |  */ | 
 |  | 
 | #include <linux/module.h> | 
 | #include <linux/kernel.h> | 
 | #include <linux/errno.h> | 
 | #include <linux/string.h> | 
 | #include <linux/mm.h> | 
 | #include <linux/tty.h> | 
 | #include <linux/slab.h> | 
 | #include <linux/delay.h> | 
 | #include <linux/fb.h> | 
 | #include <linux/init.h> | 
 |  | 
 |     /* | 
 |      *  This is just simple sample code. | 
 |      * | 
 |      *  No warranty that it actually compiles. | 
 |      *  Even less warranty that it actually works :-) | 
 |      */ | 
 |  | 
 | /* | 
 |  *  If your driver supports multiple boards, you should make the   | 
 |  *  below data types arrays, or allocate them dynamically (using kmalloc()).  | 
 |  */  | 
 |  | 
 | /*  | 
 |  * This structure defines the hardware state of the graphics card. Normally | 
 |  * you place this in a header file in linux/include/video. This file usually | 
 |  * also includes register information. That allows other driver subsystems | 
 |  * and userland applications the ability to use the same header file to  | 
 |  * avoid duplicate work and easy porting of software.  | 
 |  */ | 
 | struct xxx_par; | 
 |  | 
 | /* | 
 |  * Here we define the default structs fb_fix_screeninfo and fb_var_screeninfo | 
 |  * if we don't use modedb. If we do use modedb see xxxfb_init how to use it | 
 |  * to get a fb_var_screeninfo. Otherwise define a default var as well.  | 
 |  */ | 
 | static struct fb_fix_screeninfo xxxfb_fix __initdata = { | 
 | 	.id =		"FB's name",  | 
 | 	.type =		FB_TYPE_PACKED_PIXELS, | 
 | 	.visual =	FB_VISUAL_PSEUDOCOLOR, | 
 | 	.xpanstep =	1, | 
 | 	.ypanstep =	1, | 
 | 	.ywrapstep =	1,  | 
 | 	.accel =	FB_ACCEL_NONE, | 
 | }; | 
 |  | 
 |     /* | 
 |      * 	Modern graphical hardware not only supports pipelines but some  | 
 |      *  also support multiple monitors where each display can have its   | 
 |      *  its own unique data. In this case each display could be   | 
 |      *  represented by a separate framebuffer device thus a separate  | 
 |      *  struct fb_info. Now the struct xxx_par represents the graphics | 
 |      *  hardware state thus only one exist per card. In this case the  | 
 |      *  struct xxx_par for each graphics card would be shared between  | 
 |      *  every struct fb_info that represents a framebuffer on that card.  | 
 |      *  This allows when one display changes it video resolution (info->var)  | 
 |      *  the other displays know instantly. Each display can always be | 
 |      *  aware of the entire hardware state that affects it because they share | 
 |      *  the same xxx_par struct. The other side of the coin is multiple | 
 |      *  graphics cards that pass data around until it is finally displayed | 
 |      *  on one monitor. Such examples are the voodoo 1 cards and high end | 
 |      *  NUMA graphics servers. For this case we have a bunch of pars, each | 
 |      *  one that represents a graphics state, that belong to one struct  | 
 |      *  fb_info. Their you would want to have *par point to a array of device | 
 |      *  states and have each struct fb_ops function deal with all those  | 
 |      *  states. I hope this covers every possible hardware design. If not | 
 |      *  feel free to send your ideas at jsimmons@users.sf.net  | 
 |      */ | 
 |  | 
 |     /* | 
 |      *  If your driver supports multiple boards or it supports multiple  | 
 |      *  framebuffers, you should make these arrays, or allocate them  | 
 |      *  dynamically using framebuffer_alloc() and free them with | 
 |      *  framebuffer_release(). | 
 |      */  | 
 | static struct fb_info info; | 
 |  | 
 |     /*  | 
 |      * Each one represents the state of the hardware. Most hardware have | 
 |      * just one hardware state. These here represent the default state(s).  | 
 |      */ | 
 | static struct xxx_par __initdata current_par; | 
 |  | 
 | int xxxfb_init(void); | 
 | int xxxfb_setup(char*); | 
 |  | 
 | /** | 
 |  *	xxxfb_open - Optional function. Called when the framebuffer is | 
 |  *		     first accessed. | 
 |  *	@info: frame buffer structure that represents a single frame buffer | 
 |  *	@user: tell us if the userland (value=1) or the console is accessing | 
 |  *	       the framebuffer.  | 
 |  * | 
 |  *	This function is the first function called in the framebuffer api. | 
 |  *	Usually you don't need to provide this function. The case where it  | 
 |  *	is used is to change from a text mode hardware state to a graphics | 
 |  * 	mode state.  | 
 |  * | 
 |  *	Returns negative errno on error, or zero on success. | 
 |  */ | 
 | static int xxxfb_open(const struct fb_info *info, int user) | 
 | { | 
 |     return 0; | 
 | } | 
 |  | 
 | /** | 
 |  *	xxxfb_release - Optional function. Called when the framebuffer  | 
 |  *			device is closed.  | 
 |  *	@info: frame buffer structure that represents a single frame buffer | 
 |  *	@user: tell us if the userland (value=1) or the console is accessing | 
 |  *	       the framebuffer.  | 
 |  *	 | 
 |  *	Thus function is called when we close /dev/fb or the framebuffer  | 
 |  *	console system is released. Usually you don't need this function. | 
 |  *	The case where it is usually used is to go from a graphics state | 
 |  *	to a text mode state. | 
 |  * | 
 |  *	Returns negative errno on error, or zero on success. | 
 |  */ | 
 | static int xxxfb_release(const struct fb_info *info, int user) | 
 | { | 
 |     return 0; | 
 | } | 
 |  | 
 | /** | 
 |  *      xxxfb_check_var - Optional function. Validates a var passed in.  | 
 |  *      @var: frame buffer variable screen structure | 
 |  *      @info: frame buffer structure that represents a single frame buffer  | 
 |  * | 
 |  *	Checks to see if the hardware supports the state requested by | 
 |  *	var passed in. This function does not alter the hardware state!!!  | 
 |  *	This means the data stored in struct fb_info and struct xxx_par do  | 
 |  *      not change. This includes the var inside of struct fb_info.  | 
 |  *	Do NOT change these. This function can be called on its own if we | 
 |  *	intent to only test a mode and not actually set it. The stuff in  | 
 |  *	modedb.c is a example of this. If the var passed in is slightly  | 
 |  *	off by what the hardware can support then we alter the var PASSED in | 
 |  *	to what we can do. | 
 |  * | 
 |  *      For values that are off, this function must round them _up_ to the | 
 |  *      next value that is supported by the hardware.  If the value is | 
 |  *      greater than the highest value supported by the hardware, then this | 
 |  *      function must return -EINVAL. | 
 |  * | 
 |  *      Exception to the above rule:  Some drivers have a fixed mode, ie, | 
 |  *      the hardware is already set at boot up, and cannot be changed.  In | 
 |  *      this case, it is more acceptable that this function just return | 
 |  *      a copy of the currently working var (info->var). Better is to not | 
 |  *      implement this function, as the upper layer will do the copying | 
 |  *      of the current var for you. | 
 |  * | 
 |  *      Note:  This is the only function where the contents of var can be | 
 |  *      freely adjusted after the driver has been registered. If you find | 
 |  *      that you have code outside of this function that alters the content | 
 |  *      of var, then you are doing something wrong.  Note also that the | 
 |  *      contents of info->var must be left untouched at all times after | 
 |  *      driver registration. | 
 |  * | 
 |  *	Returns negative errno on error, or zero on success. | 
 |  */ | 
 | static int xxxfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info) | 
 | { | 
 |     /* ... */ | 
 |     return 0;	   	 | 
 | } | 
 |  | 
 | /** | 
 |  *      xxxfb_set_par - Optional function. Alters the hardware state. | 
 |  *      @info: frame buffer structure that represents a single frame buffer | 
 |  * | 
 |  *	Using the fb_var_screeninfo in fb_info we set the resolution of the | 
 |  *	this particular framebuffer. This function alters the par AND the | 
 |  *	fb_fix_screeninfo stored in fb_info. It doesn't not alter var in  | 
 |  *	fb_info since we are using that data. This means we depend on the | 
 |  *	data in var inside fb_info to be supported by the hardware.  | 
 |  * | 
 |  *      This function is also used to recover/restore the hardware to a | 
 |  *      known working state. | 
 |  * | 
 |  *	xxxfb_check_var is always called before xxxfb_set_par to ensure that | 
 |  *      the contents of var is always valid. | 
 |  * | 
 |  *	Again if you can't change the resolution you don't need this function. | 
 |  * | 
 |  *      However, even if your hardware does not support mode changing, | 
 |  *      a set_par might be needed to at least initialize the hardware to | 
 |  *      a known working state, especially if it came back from another | 
 |  *      process that also modifies the same hardware, such as X. | 
 |  * | 
 |  *      If this is the case, a combination such as the following should work: | 
 |  * | 
 |  *      static int xxxfb_check_var(struct fb_var_screeninfo *var, | 
 |  *                                struct fb_info *info) | 
 |  *      { | 
 |  *              *var = info->var; | 
 |  *              return 0; | 
 |  *      } | 
 |  * | 
 |  *      static int xxxfb_set_par(struct fb_info *info) | 
 |  *      { | 
 |  *              init your hardware here | 
 |  *      } | 
 |  * | 
 |  *	Returns negative errno on error, or zero on success. | 
 |  */ | 
 | static int xxxfb_set_par(struct fb_info *info) | 
 | { | 
 |     struct xxx_par *par = info->par; | 
 |     /* ... */ | 
 |     return 0;	 | 
 | } | 
 |  | 
 | /** | 
 |  *  	xxxfb_setcolreg - Optional function. Sets a color register. | 
 |  *      @regno: Which register in the CLUT we are programming  | 
 |  *      @red: The red value which can be up to 16 bits wide  | 
 |  *	@green: The green value which can be up to 16 bits wide  | 
 |  *	@blue:  The blue value which can be up to 16 bits wide. | 
 |  *	@transp: If supported, the alpha value which can be up to 16 bits wide. | 
 |  *      @info: frame buffer info structure | 
 |  *  | 
 |  *  	Set a single color register. The values supplied have a 16 bit | 
 |  *  	magnitude which needs to be scaled in this function for the hardware.  | 
 |  *	Things to take into consideration are how many color registers, if | 
 |  *	any, are supported with the current color visual. With truecolor mode | 
 |  *	no color palettes are supported. Here a pseudo palette is created | 
 |  *	which we store the value in pseudo_palette in struct fb_info. For | 
 |  *	pseudocolor mode we have a limited color palette. To deal with this | 
 |  *	we can program what color is displayed for a particular pixel value. | 
 |  *	DirectColor is similar in that we can program each color field. If | 
 |  *	we have a static colormap we don't need to implement this function.  | 
 |  *  | 
 |  *	Returns negative errno on error, or zero on success. | 
 |  */ | 
 | static int xxxfb_setcolreg(unsigned regno, unsigned red, unsigned green, | 
 | 			   unsigned blue, unsigned transp, | 
 | 			   const struct fb_info *info) | 
 | { | 
 |     if (regno >= 256)  /* no. of hw registers */ | 
 |        return -EINVAL; | 
 |     /* | 
 |      * Program hardware... do anything you want with transp | 
 |      */ | 
 |  | 
 |     /* grayscale works only partially under directcolor */ | 
 |     if (info->var.grayscale) { | 
 |        /* grayscale = 0.30*R + 0.59*G + 0.11*B */ | 
 |        red = green = blue = (red * 77 + green * 151 + blue * 28) >> 8; | 
 |     } | 
 |  | 
 |     /* Directcolor: | 
 |      *   var->{color}.offset contains start of bitfield | 
 |      *   var->{color}.length contains length of bitfield | 
 |      *   {hardwarespecific} contains width of DAC | 
 |      *   pseudo_palette[X] is programmed to (X << red.offset) | | 
 |      *                                      (X << green.offset) | | 
 |      *                                      (X << blue.offset) | 
 |      *   RAMDAC[X] is programmed to (red, green, blue) | 
 |      *   color depth = SUM(var->{color}.length) | 
 |      * | 
 |      * Pseudocolor: | 
 |      *    var->{color}.offset is 0 | 
 |      *    var->{color}.length contains width of DAC or the number of unique | 
 |      *                        colors available (color depth) | 
 |      *    pseudo_palette is not used | 
 |      *    RAMDAC[X] is programmed to (red, green, blue) | 
 |      *    color depth = var->{color}.length | 
 |      * | 
 |      * Static pseudocolor: | 
 |      *    same as Pseudocolor, but the RAMDAC is not programmed (read-only) | 
 |      * | 
 |      * Mono01/Mono10: | 
 |      *    Has only 2 values, black on white or white on black (fg on bg), | 
 |      *    var->{color}.offset is 0 | 
 |      *    white = (1 << var->{color}.length) - 1, black = 0 | 
 |      *    pseudo_palette is not used | 
 |      *    RAMDAC does not exist | 
 |      *    color depth is always 2 | 
 |      * | 
 |      * Truecolor: | 
 |      *    does not use RAMDAC (usually has 3 of them). | 
 |      *    var->{color}.offset contains start of bitfield | 
 |      *    var->{color}.length contains length of bitfield | 
 |      *    pseudo_palette is programmed to (red << red.offset) | | 
 |      *                                    (green << green.offset) | | 
 |      *                                    (blue << blue.offset) | | 
 |      *                                    (transp << transp.offset) | 
 |      *    RAMDAC does not exist | 
 |      *    color depth = SUM(var->{color}.length}) | 
 |      * | 
 |      *  The color depth is used by fbcon for choosing the logo and also | 
 |      *  for color palette transformation if color depth < 4 | 
 |      * | 
 |      *  As can be seen from the above, the field bits_per_pixel is _NOT_ | 
 |      *  a criteria for describing the color visual. | 
 |      * | 
 |      *  A common mistake is assuming that bits_per_pixel <= 8 is pseudocolor, | 
 |      *  and higher than that, true/directcolor.  This is incorrect, one needs | 
 |      *  to look at the fix->visual. | 
 |      * | 
 |      *  Another common mistake is using bits_per_pixel to calculate the color | 
 |      *  depth.  The bits_per_pixel field does not directly translate to color | 
 |      *  depth. You have to compute for the color depth (using the color | 
 |      *  bitfields) and fix->visual as seen above. | 
 |      */ | 
 |  | 
 |     /* | 
 |      * This is the point where the color is converted to something that | 
 |      * is acceptable by the hardware. | 
 |      */ | 
 | #define CNVT_TOHW(val,width) ((((val)<<(width))+0x7FFF-(val))>>16) | 
 |     red = CNVT_TOHW(red, info->var.red.length); | 
 |     green = CNVT_TOHW(green, info->var.green.length); | 
 |     blue = CNVT_TOHW(blue, info->var.blue.length); | 
 |     transp = CNVT_TOHW(transp, info->var.transp.length); | 
 | #undef CNVT_TOHW | 
 |     /* | 
 |      * This is the point where the function feeds the color to the hardware | 
 |      * palette after converting the colors to something acceptable by | 
 |      * the hardware. Note, only FB_VISUAL_DIRECTCOLOR and | 
 |      * FB_VISUAL_PSEUDOCOLOR visuals need to write to the hardware palette. | 
 |      * If you have code that writes to the hardware CLUT, and it's not | 
 |      * any of the above visuals, then you are doing something wrong. | 
 |      */ | 
 |     if (info->fix.visual == FB_VISUAL_DIRECTCOLOR || | 
 | 	info->fix.visual == FB_VISUAL_TRUECOLOR) | 
 | 	    write_{red|green|blue|transp}_to_clut(); | 
 |  | 
 |     /* This is the point were you need to fill up the contents of | 
 |      * info->pseudo_palette. This structure is used _only_ by fbcon, thus | 
 |      * it only contains 16 entries to match the number of colors supported | 
 |      * by the console. The pseudo_palette is used only if the visual is | 
 |      * in directcolor or truecolor mode.  With other visuals, the | 
 |      * pseudo_palette is not used. (This might change in the future.) | 
 |      * | 
 |      * The contents of the pseudo_palette is in raw pixel format.  Ie, each | 
 |      * entry can be written directly to the framebuffer without any conversion. | 
 |      * The pseudo_palette is (void *).  However, if using the generic | 
 |      * drawing functions (cfb_imageblit, cfb_fillrect), the pseudo_palette | 
 |      * must be casted to (u32 *) _regardless_ of the bits per pixel. If the | 
 |      * driver is using its own drawing functions, then it can use whatever | 
 |      * size it wants. | 
 |      */ | 
 |     if (info->fix.visual == FB_VISUAL_TRUECOLOR || | 
 | 	info->fix.visual == FB_VISUAL_DIRECTCOLOR) { | 
 | 	    u32 v; | 
 |  | 
 | 	    if (regno >= 16) | 
 | 		    return -EINVAL; | 
 |  | 
 | 	    v = (red << info->var.red.offset) | | 
 | 		    (green << info->var.green.offset) | | 
 | 		    (blue << info->var.blue.offset) | | 
 | 		    (transp << info->var.transp.offset); | 
 |  | 
 | 	    ((u32*)(info->pseudo_palette))[regno] = v; | 
 |     } | 
 |  | 
 |     /* ... */ | 
 |     return 0; | 
 | } | 
 |  | 
 | /** | 
 |  *      xxxfb_pan_display - NOT a required function. Pans the display. | 
 |  *      @var: frame buffer variable screen structure | 
 |  *      @info: frame buffer structure that represents a single frame buffer | 
 |  * | 
 |  *	Pan (or wrap, depending on the `vmode' field) the display using the | 
 |  *  	`xoffset' and `yoffset' fields of the `var' structure. | 
 |  *  	If the values don't fit, return -EINVAL. | 
 |  * | 
 |  *      Returns negative errno on error, or zero on success. | 
 |  */ | 
 | static int xxxfb_pan_display(struct fb_var_screeninfo *var, | 
 | 			     const struct fb_info *info) | 
 | { | 
 |     /* | 
 |      * If your hardware does not support panning, _do_ _not_ implement this | 
 |      * function. Creating a dummy function will just confuse user apps. | 
 |      */ | 
 |  | 
 |     /* | 
 |      * Note that even if this function is fully functional, a setting of | 
 |      * 0 in both xpanstep and ypanstep means that this function will never | 
 |      * get called. | 
 |      */ | 
 |  | 
 |     /* ... */ | 
 |     return 0; | 
 | } | 
 |  | 
 | /** | 
 |  *      xxxfb_blank - NOT a required function. Blanks the display. | 
 |  *      @blank_mode: the blank mode we want.  | 
 |  *      @info: frame buffer structure that represents a single frame buffer | 
 |  * | 
 |  *      Blank the screen if blank_mode != FB_BLANK_UNBLANK, else unblank. | 
 |  *      Return 0 if blanking succeeded, != 0 if un-/blanking failed due to | 
 |  *      e.g. a video mode which doesn't support it. | 
 |  * | 
 |  *      Implements VESA suspend and powerdown modes on hardware that supports | 
 |  *      disabling hsync/vsync: | 
 |  * | 
 |  *      FB_BLANK_NORMAL = display is blanked, syncs are on. | 
 |  *      FB_BLANK_HSYNC_SUSPEND = hsync off | 
 |  *      FB_BLANK_VSYNC_SUSPEND = vsync off | 
 |  *      FB_BLANK_POWERDOWN =  hsync and vsync off | 
 |  * | 
 |  *      If implementing this function, at least support FB_BLANK_UNBLANK. | 
 |  *      Return !0 for any modes that are unimplemented. | 
 |  * | 
 |  */ | 
 | static int xxxfb_blank(int blank_mode, const struct fb_info *info) | 
 | { | 
 |     /* ... */ | 
 |     return 0; | 
 | } | 
 |  | 
 | /* ------------ Accelerated Functions --------------------- */ | 
 |  | 
 | /* | 
 |  * We provide our own functions if we have hardware acceleration | 
 |  * or non packed pixel format layouts. If we have no hardware  | 
 |  * acceleration, we can use a generic unaccelerated function. If using | 
 |  * a pack pixel format just use the functions in cfb_*.c. Each file  | 
 |  * has one of the three different accel functions we support. | 
 |  */ | 
 |  | 
 | /** | 
 |  *      xxxfb_fillrect - REQUIRED function. Can use generic routines if  | 
 |  *		 	 non acclerated hardware and packed pixel based. | 
 |  *			 Draws a rectangle on the screen.		 | 
 |  * | 
 |  *      @info: frame buffer structure that represents a single frame buffer | 
 |  *	@region: The structure representing the rectangular region we  | 
 |  *		 wish to draw to. | 
 |  * | 
 |  *	This drawing operation places/removes a retangle on the screen  | 
 |  *	depending on the rastering operation with the value of color which | 
 |  *	is in the current color depth format. | 
 |  */ | 
 | void xxfb_fillrect(struct fb_info *p, const struct fb_fillrect *region) | 
 | { | 
 | /*	Meaning of struct fb_fillrect | 
 |  * | 
 |  *	@dx: The x and y corrdinates of the upper left hand corner of the  | 
 |  *	@dy: area we want to draw to.  | 
 |  *	@width: How wide the rectangle is we want to draw. | 
 |  *	@height: How tall the rectangle is we want to draw. | 
 |  *	@color:	The color to fill in the rectangle with.  | 
 |  *	@rop: The raster operation. We can draw the rectangle with a COPY | 
 |  *	      of XOR which provides erasing effect.  | 
 |  */ | 
 | } | 
 |  | 
 | /** | 
 |  *      xxxfb_copyarea - REQUIRED function. Can use generic routines if | 
 |  *                       non acclerated hardware and packed pixel based. | 
 |  *                       Copies one area of the screen to another area. | 
 |  * | 
 |  *      @info: frame buffer structure that represents a single frame buffer | 
 |  *      @area: Structure providing the data to copy the framebuffer contents | 
 |  *	       from one region to another. | 
 |  * | 
 |  *      This drawing operation copies a rectangular area from one area of the | 
 |  *	screen to another area. | 
 |  */ | 
 | void xxxfb_copyarea(struct fb_info *p, const struct fb_copyarea *area)  | 
 | { | 
 | /* | 
 |  *      @dx: The x and y coordinates of the upper left hand corner of the | 
 |  *	@dy: destination area on the screen. | 
 |  *      @width: How wide the rectangle is we want to copy. | 
 |  *      @height: How tall the rectangle is we want to copy. | 
 |  *      @sx: The x and y coordinates of the upper left hand corner of the | 
 |  *      @sy: source area on the screen. | 
 |  */ | 
 | } | 
 |  | 
 |  | 
 | /** | 
 |  *      xxxfb_imageblit - REQUIRED function. Can use generic routines if | 
 |  *                        non acclerated hardware and packed pixel based. | 
 |  *                        Copies a image from system memory to the screen.  | 
 |  * | 
 |  *      @info: frame buffer structure that represents a single frame buffer | 
 |  *	@image:	structure defining the image. | 
 |  * | 
 |  *      This drawing operation draws a image on the screen. It can be a  | 
 |  *	mono image (needed for font handling) or a color image (needed for | 
 |  *	tux).  | 
 |  */ | 
 | void xxxfb_imageblit(struct fb_info *p, const struct fb_image *image)  | 
 | { | 
 | /* | 
 |  *      @dx: The x and y coordinates of the upper left hand corner of the | 
 |  *	@dy: destination area to place the image on the screen. | 
 |  *      @width: How wide the image is we want to copy. | 
 |  *      @height: How tall the image is we want to copy. | 
 |  *      @fg_color: For mono bitmap images this is color data for      | 
 |  *      @bg_color: the foreground and background of the image to | 
 |  *		   write directly to the frmaebuffer. | 
 |  *	@depth:	How many bits represent a single pixel for this image. | 
 |  *	@data: The actual data used to construct the image on the display. | 
 |  *	@cmap: The colormap used for color images.    | 
 |  */ | 
 |  | 
 | /* | 
 |  * The generic function, cfb_imageblit, expects that the bitmap scanlines are | 
 |  * padded to the next byte.  Most hardware accelerators may require padding to | 
 |  * the next u16 or the next u32.  If that is the case, the driver can specify | 
 |  * this by setting info->pixmap.scan_align = 2 or 4.  See a more | 
 |  * comprehensive description of the pixmap below. | 
 |  */ | 
 | } | 
 |  | 
 | /** | 
 |  *	xxxfb_cursor - 	OPTIONAL. If your hardware lacks support | 
 |  *			for a cursor, leave this field NULL. | 
 |  * | 
 |  *      @info: frame buffer structure that represents a single frame buffer | 
 |  *	@cursor: structure defining the cursor to draw. | 
 |  * | 
 |  *      This operation is used to set or alter the properities of the | 
 |  *	cursor. | 
 |  * | 
 |  *	Returns negative errno on error, or zero on success. | 
 |  */ | 
 | int xxxfb_cursor(struct fb_info *info, struct fb_cursor *cursor) | 
 | { | 
 | /* | 
 |  *      @set: 	Which fields we are altering in struct fb_cursor  | 
 |  *	@enable: Disable or enable the cursor  | 
 |  *      @rop: 	The bit operation we want to do.  | 
 |  *      @mask:  This is the cursor mask bitmap.  | 
 |  *      @dest:  A image of the area we are going to display the cursor. | 
 |  *		Used internally by the driver.	  | 
 |  *      @hot:	The hot spot.  | 
 |  *	@image:	The actual data for the cursor image. | 
 |  * | 
 |  *      NOTES ON FLAGS (cursor->set): | 
 |  * | 
 |  *      FB_CUR_SETIMAGE - the cursor image has changed (cursor->image.data) | 
 |  *      FB_CUR_SETPOS   - the cursor position has changed (cursor->image.dx|dy) | 
 |  *      FB_CUR_SETHOT   - the cursor hot spot has changed (cursor->hot.dx|dy) | 
 |  *      FB_CUR_SETCMAP  - the cursor colors has changed (cursor->fg_color|bg_color) | 
 |  *      FB_CUR_SETSHAPE - the cursor bitmask has changed (cursor->mask) | 
 |  *      FB_CUR_SETSIZE  - the cursor size has changed (cursor->width|height) | 
 |  *      FB_CUR_SETALL   - everything has changed | 
 |  * | 
 |  *      NOTES ON ROPs (cursor->rop, Raster Operation) | 
 |  * | 
 |  *      ROP_XOR         - cursor->image.data XOR cursor->mask | 
 |  *      ROP_COPY        - curosr->image.data AND cursor->mask | 
 |  * | 
 |  *      OTHER NOTES: | 
 |  * | 
 |  *      - fbcon only supports a 2-color cursor (cursor->image.depth = 1) | 
 |  *      - The fb_cursor structure, @cursor, _will_ always contain valid | 
 |  *        fields, whether any particular bitfields in cursor->set is set | 
 |  *        or not. | 
 |  */ | 
 | } | 
 |  | 
 | /** | 
 |  *	xxxfb_rotate -  NOT a required function. If your hardware | 
 |  *			supports rotation the whole screen then  | 
 |  *			you would provide a hook for this.  | 
 |  * | 
 |  *      @info: frame buffer structure that represents a single frame buffer | 
 |  *	@angle: The angle we rotate the screen.    | 
 |  * | 
 |  *      This operation is used to set or alter the properities of the | 
 |  *	cursor. | 
 |  */ | 
 | void xxxfb_rotate(struct fb_info *info, int angle) | 
 | { | 
 | /* Will be deprecated */ | 
 | } | 
 |  | 
 | /** | 
 |  *	xxxfb_poll - NOT a required function. The purpose of this | 
 |  *		     function is to provide a way for some process | 
 |  *		     to wait until a specific hardware event occurs | 
 |  *		     for the framebuffer device. | 
 |  * 				  | 
 |  *      @info: frame buffer structure that represents a single frame buffer | 
 |  *	@wait: poll table where we store process that await a event.      | 
 |  */ | 
 | void xxxfb_poll(struct fb_info *info, poll_table *wait) | 
 | { | 
 | } | 
 |  | 
 | /** | 
 |  *	xxxfb_sync - NOT a required function. Normally the accel engine  | 
 |  *		     for a graphics card take a specific amount of time. | 
 |  *		     Often we have to wait for the accelerator to finish | 
 |  *		     its operation before we can write to the framebuffer | 
 |  *		     so we can have consistent display output.  | 
 |  * | 
 |  *      @info: frame buffer structure that represents a single frame buffer | 
 |  * | 
 |  *      If the driver has implemented its own hardware-based drawing function, | 
 |  *      implementing this function is highly recommended. | 
 |  */ | 
 | void xxxfb_sync(struct fb_info *info) | 
 | { | 
 | } | 
 |  | 
 |     /* | 
 |      *  Initialization | 
 |      */ | 
 |  | 
 | /* static int __init xxfb_probe (struct device *device) -- for platform devs */ | 
 | static int __init xxxfb_probe(struct pci_dev *dev, | 
 | 			      const_struct pci_device_id *ent) | 
 | { | 
 |     struct fb_info *info; | 
 |     struct xxx_par *par; | 
 |     struct device = &dev->dev; /* for pci drivers */ | 
 |     int cmap_len, retval;	 | 
 |     | 
 |     /* | 
 |      * Dynamically allocate info and par | 
 |      */ | 
 |     info = framebuffer_alloc(sizeof(struct xxx_par), device); | 
 |  | 
 |     if (!info) { | 
 | 	    /* goto error path */ | 
 |     } | 
 |  | 
 |     par = info->par; | 
 |  | 
 |     /*  | 
 |      * Here we set the screen_base to the virtual memory address | 
 |      * for the framebuffer. Usually we obtain the resource address | 
 |      * from the bus layer and then translate it to virtual memory | 
 |      * space via ioremap. Consult ioport.h.  | 
 |      */ | 
 |     info->screen_base = framebuffer_virtual_memory; | 
 |     info->fbops = &xxxfb_ops; | 
 |     info->fix = xxxfb_fix; /* this will be the only time xxxfb_fix will be | 
 | 			    * used, so mark it as __initdata | 
 | 			    */ | 
 |     info->pseudo_palette = pseudo_palette; /* The pseudopalette is an | 
 | 					    * 16-member array | 
 | 					    */ | 
 |     /* | 
 |      * Set up flags to indicate what sort of acceleration your | 
 |      * driver can provide (pan/wrap/copyarea/etc.) and whether it | 
 |      * is a module -- see FBINFO_* in include/linux/fb.h | 
 |      * | 
 |      * If your hardware can support any of the hardware accelerated functions | 
 |      * fbcon performance will improve if info->flags is set properly. | 
 |      * | 
 |      * FBINFO_HWACCEL_COPYAREA - hardware moves | 
 |      * FBINFO_HWACCEL_FILLRECT - hardware fills | 
 |      * FBINFO_HWACCEL_IMAGEBLIT - hardware mono->color expansion | 
 |      * FBINFO_HWACCEL_YPAN - hardware can pan display in y-axis | 
 |      * FBINFO_HWACCEL_YWRAP - hardware can wrap display in y-axis | 
 |      * FBINFO_HWACCEL_DISABLED - supports hardware accels, but disabled | 
 |      * FBINFO_READS_FAST - if set, prefer moves over mono->color expansion | 
 |      * FBINFO_MISC_TILEBLITTING - hardware can do tile blits | 
 |      * | 
 |      * NOTE: These are for fbcon use only. | 
 |      */ | 
 |     info->flags = FBINFO_DEFAULT; | 
 |  | 
 | /********************* This stage is optional ******************************/ | 
 |      /* | 
 |      * The struct pixmap is a scratch pad for the drawing functions. This | 
 |      * is where the monochrome bitmap is constructed by the higher layers | 
 |      * and then passed to the accelerator.  For drivers that uses | 
 |      * cfb_imageblit, you can skip this part.  For those that have a more | 
 |      * rigorous requirement, this stage is needed | 
 |      */ | 
 |  | 
 |     /* PIXMAP_SIZE should be small enough to optimize drawing, but not | 
 |      * large enough that memory is wasted.  A safe size is | 
 |      * (max_xres * max_font_height/8). max_xres is driver dependent, | 
 |      * max_font_height is 32. | 
 |      */ | 
 |     info->pixmap.addr = kmalloc(PIXMAP_SIZE, GFP_KERNEL); | 
 |     if (!info->pixmap.addr) { | 
 | 	    /* goto error */ | 
 |     } | 
 |  | 
 |     info->pixmap.size = PIXMAP_SIZE; | 
 |  | 
 |     /* | 
 |      * FB_PIXMAP_SYSTEM - memory is in system ram | 
 |      * FB_PIXMAP_IO     - memory is iomapped | 
 |      * FB_PIXMAP_SYNC   - if set, will call fb_sync() per access to pixmap, | 
 |      *                    usually if FB_PIXMAP_IO is set. | 
 |      * | 
 |      * Currently, FB_PIXMAP_IO is unimplemented. | 
 |      */ | 
 |     info->pixmap.flags = FB_PIXMAP_SYSTEM; | 
 |  | 
 |     /* | 
 |      * scan_align is the number of padding for each scanline.  It is in bytes. | 
 |      * Thus for accelerators that need padding to the next u32, put 4 here. | 
 |      */ | 
 |     info->pixmap.scan_align = 4; | 
 |  | 
 |     /* | 
 |      * buf_align is the amount to be padded for the buffer. For example, | 
 |      * the i810fb needs a scan_align of 2 but expects it to be fed with | 
 |      * dwords, so a buf_align = 4 is required. | 
 |      */ | 
 |     info->pixmap.buf_align = 4; | 
 |  | 
 |     /* access_align is how many bits can be accessed from the framebuffer | 
 |      * ie. some epson cards allow 16-bit access only.  Most drivers will | 
 |      * be safe with u32 here. | 
 |      * | 
 |      * NOTE: This field is currently unused. | 
 |      */ | 
 |     info->pixmap.scan_align = 32 | 
 | /***************************** End optional stage ***************************/ | 
 |  | 
 |     /* | 
 |      * This should give a reasonable default video mode. The following is | 
 |      * done when we can set a video mode.  | 
 |      */ | 
 |     if (!mode_option) | 
 | 	mode_option = "640x480@60";	 	 | 
 |  | 
 |     retval = fb_find_mode(info->var, info, mode_option, NULL, 0, NULL, 8); | 
 |    | 
 |     if (!retval || retval == 4) | 
 | 	return -EINVAL;			 | 
 |  | 
 |     /* This has to been done !!! */	 | 
 |     fb_alloc_cmap(info->cmap, cmap_len, 0); | 
 | 	 | 
 |     /*  | 
 |      * The following is done in the case of having hardware with a static  | 
 |      * mode. If we are setting the mode ourselves we don't call this.  | 
 |      */	 | 
 |     info->var = xxxfb_var; | 
 |  | 
 |     /* | 
 |      * For drivers that can... | 
 |      */ | 
 |     xxxfb_check_var(&info->var, info); | 
 |  | 
 |     /* | 
 |      * Does a call to fb_set_par() before register_framebuffer needed?  This | 
 |      * will depend on you and the hardware.  If you are sure that your driver | 
 |      * is the only device in the system, a call to fb_set_par() is safe. | 
 |      * | 
 |      * Hardware in x86 systems has a VGA core.  Calling set_par() at this | 
 |      * point will corrupt the VGA console, so it might be safer to skip a | 
 |      * call to set_par here and just allow fbcon to do it for you. | 
 |      */ | 
 |     /* xxxfb_set_par(info); */ | 
 |  | 
 |     if (register_framebuffer(info) < 0) | 
 | 	return -EINVAL; | 
 |     printk(KERN_INFO "fb%d: %s frame buffer device\n", info->node, | 
 | 	   info->fix.id); | 
 |     pci_set_drvdata(dev, info); /* or dev_set_drvdata(device, info) */ | 
 |     return 0; | 
 | } | 
 |  | 
 |     /* | 
 |      *  Cleanup | 
 |      */ | 
 | /* static void __exit xxxfb_remove(struct device *device) */ | 
 | static void __exit xxxfb_remove(struct pci_dev *dev) | 
 | { | 
 | 	struct fb_info *info = pci_get_drv_data(dev); | 
 | 	/* or dev_get_drv_data(device); */ | 
 |  | 
 | 	if (info) { | 
 | 		unregister_framebuffer(info); | 
 | 		fb_dealloc_cmap(&info.cmap); | 
 | 		/* ... */ | 
 | 		framebuffer_release(info); | 
 | 	} | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | #if CONFIG_PCI | 
 | /* For PCI drivers */ | 
 | static struct pci_driver xxxfb_driver = { | 
 | 	.name =		"xxxfb", | 
 | 	.id_table =	xxxfb_devices, | 
 | 	.probe =	xxxfb_probe, | 
 | 	.remove =	__devexit_p(xxxfb_remove), | 
 | 	.suspend =      xxxfb_suspend, /* optional */ | 
 | 	.resume =       xxxfb_resume,  /* optional */ | 
 | }; | 
 |  | 
 | static int __init xxxfb_init(void) | 
 | { | 
 | 	/* | 
 | 	 *  For kernel boot options (in 'video=xxxfb:<options>' format) | 
 | 	 */ | 
 | #ifndef MODULE | 
 | 	char *option = NULL; | 
 |  | 
 | 	if (fb_get_options("xxxfb", &option)) | 
 | 		return -ENODEV; | 
 | 	xxxfb_setup(option); | 
 | #endif | 
 |  | 
 | 	return pci_register_driver(&xxxfb_driver); | 
 | } | 
 |  | 
 | static void __exit xxxfb_exit(void) | 
 | { | 
 | 	pci_unregister_driver(&xxxfb_driver); | 
 | } | 
 | #else | 
 | #include <linux/platform_device.h> | 
 | /* for platform devices */ | 
 | static struct device_driver xxxfb_driver = { | 
 | 	.name = "xxxfb", | 
 | 	.bus  = &platform_bus_type, | 
 | 	.probe = xxxfb_probe, | 
 | 	.remove = xxxfb_remove, | 
 | 	.suspend = xxxfb_suspend, /* optional */ | 
 | 	.resume = xxxfb_resume,   /* optional */ | 
 | }; | 
 |  | 
 | static struct platform_device xxxfb_device = { | 
 | 	.name = "xxxfb", | 
 | }; | 
 |  | 
 | static int __init xxxfb_init(void) | 
 | { | 
 | 	int ret; | 
 | 	/* | 
 | 	 *  For kernel boot options (in 'video=xxxfb:<options>' format) | 
 | 	 */ | 
 | #ifndef MODULE | 
 | 	char *option = NULL; | 
 |  | 
 | 	if (fb_get_options("xxxfb", &option)) | 
 | 		return -ENODEV; | 
 | 	xxxfb_setup(option); | 
 | #endif | 
 | 	ret = driver_register(&xxxfb_driver); | 
 |  | 
 | 	if (!ret) { | 
 | 		ret = platform_device_register(&xxxfb_device); | 
 | 		if (ret) | 
 | 			driver_unregister(&xxxfb_driver); | 
 | 	} | 
 |  | 
 | 	return ret; | 
 | } | 
 |  | 
 | static void __exit xxxfb_exit(void) | 
 | { | 
 | 	platform_device_unregister(&xxxfb_device); | 
 | 	driver_unregister(&xxxfb_driver); | 
 | } | 
 | #endif | 
 |  | 
 |     /* | 
 |      *  Setup | 
 |      */ | 
 |  | 
 | /*  | 
 |  * Only necessary if your driver takes special options, | 
 |  * otherwise we fall back on the generic fb_setup(). | 
 |  */ | 
 | int __init xxxfb_setup(char *options) | 
 | { | 
 |     /* Parse user speficied options (`video=xxxfb:') */ | 
 | } | 
 |  | 
 | /* ------------------------------------------------------------------------- */ | 
 |  | 
 |     /* | 
 |      *  Frame buffer operations | 
 |      */ | 
 |  | 
 | static struct fb_ops xxxfb_ops = { | 
 | 	.owner		= THIS_MODULE, | 
 | 	.fb_open	= xxxfb_open, | 
 | 	.fb_read	= xxxfb_read, | 
 | 	.fb_write	= xxxfb_write, | 
 | 	.fb_release	= xxxfb_release, | 
 | 	.fb_check_var	= xxxfb_check_var, | 
 | 	.fb_set_par	= xxxfb_set_par,	 | 
 | 	.fb_setcolreg	= xxxfb_setcolreg, | 
 | 	.fb_blank	= xxxfb_blank, | 
 | 	.fb_pan_display	= xxxfb_pan_display,	 | 
 | 	.fb_fillrect	= xxxfb_fillrect, 	/* Needed !!! */  | 
 | 	.fb_copyarea	= xxxfb_copyarea,	/* Needed !!! */  | 
 | 	.fb_imageblit	= xxxfb_imageblit,	/* Needed !!! */ | 
 | 	.fb_cursor	= xxxfb_cursor,		/* Optional !!! */ | 
 | 	.fb_rotate	= xxxfb_rotate, | 
 | 	.fb_poll	= xxxfb_poll, | 
 | 	.fb_sync	= xxxfb_sync, | 
 | 	.fb_ioctl	= xxxfb_ioctl, | 
 | 	.fb_mmap	= xxxfb_mmap,	 | 
 | }; | 
 |  | 
 | /* ------------------------------------------------------------------------- */ | 
 |  | 
 |  | 
 |     /* | 
 |      *  Modularization | 
 |      */ | 
 |  | 
 | module_init(xxxfb_init); | 
 | module_exit(xxxfb_cleanup); | 
 |  | 
 | MODULE_LICENSE("GPL"); |