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Diffstat (limited to 'drivers/video/skeletonfb.c')
| -rw-r--r-- | drivers/video/skeletonfb.c | 684 |
1 files changed, 684 insertions, 0 deletions
diff --git a/drivers/video/skeletonfb.c b/drivers/video/skeletonfb.c new file mode 100644 index 000000000000..7b43716ab665 --- /dev/null +++ b/drivers/video/skeletonfb.c @@ -0,0 +1,684 @@ +/* + * 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 kmalloc()). + */ +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. If the hardware doesn't support mode change + * a -EINVAL will be returned by the upper layers. You don't need to + * implement this function then. If you hardware doesn't support + * changing the resolution then this function is not needed. In this + * case the driver woudl just provide a var that represents the static + * state the screen is in. + * + * Returns negative errno on error, or zero on success. + */ +static int xxxfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info) +{ + const struct xxx_par *par = (const struct xxx_par *) info->par; + /* ... */ + 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. + * xxxfb_check_var is always called before xxxfb_set_par to ensure this. + * Again if you can't change the resolution you don't need this function. + * + * Returns negative errno on error, or zero on success. + */ +static int xxxfb_set_par(struct fb_info *info) +{ + struct xxx_par *par = (struct xxx_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 + * cmap[X] is programmed to (X << red.offset) | (X << green.offset) | (X << blue.offset) + * RAMDAC[X] is programmed to (red, green, blue) + * + * Pseudocolor: + * uses offset = 0 && length = DAC register width. + * var->{color}.offset is 0 + * var->{color}.length contains widht of DAC + * cmap is not used + * DAC[X] is programmed to (red, green, blue) + * Truecolor: + * does not use RAMDAC (usually has 3 of them). + * var->{color}.offset contains start of bitfield + * var->{color}.length contains length of bitfield + * cmap is programmed to (red << red.offset) | (green << green.offset) | + * (blue << blue.offset) | (transp << transp.offset) + * RAMDAC does not exist + */ +#define CNVT_TOHW(val,width) ((((val)<<(width))+0x7FFF-(val))>>16) + switch (info->fix.visual) { + case FB_VISUAL_TRUECOLOR: + case FB_VISUAL_PSEUDOCOLOR: + 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); + break; + case FB_VISUAL_DIRECTCOLOR: + /* example here assumes 8 bit DAC. Might be different + * for your hardware */ + red = CNVT_TOHW(red, 8); + green = CNVT_TOHW(green, 8); + blue = CNVT_TOHW(blue, 8); + /* hey, there is bug in transp handling... */ + transp = CNVT_TOHW(transp, 8); + break; + } +#undef CNVT_TOHW + /* Truecolor has hardware independent palette */ + if (info->fix.visual == FB_VISUAL_TRUECOLOR) { + 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); + + switch (info->var.bits_per_pixel) { + case 8: + /* Yes some hand held devices have this. */ + ((u8*)(info->pseudo_palette))[regno] = v; + break; + case 16: + ((u16*)(info->pseudo_palette))[regno] = v; + break; + case 24: + case 32: + ((u32*)(info->pseudo_palette))[regno] = v; + break; + } + return 0; + } + /* ... */ + 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) +{ + /* ... */ + 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 != 0, 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: + * blank_mode == 2: suspend vsync + * blank_mode == 3: suspend hsync + * blank_mode == 4: powerdown + * + * Returns negative errno on error, or zero on success. + * + */ +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. + */ +} + +/** + * xxxfb_cursor - REQUIRED function. If your hardware lacks support + * for a cursor you can use the default cursor whose + * function is called soft_cursor. It will always + * work since it uses xxxfb_imageblit function which + * is required. + * + * @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) +{ +} + +/** + * 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 + */ +void xxxfb_sync(struct fb_info *info) +{ +} + + /* + * Initialization + */ + +int __init xxxfb_init(void) +{ + int cmap_len, retval; + + /* + * 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 + + /* + * 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; + info.pseudo_palette = pseudo_palette; + + /* + * 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 + */ + info.flags = FBINFO_DEFAULT; + info.par = current_par; + + /* + * 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; + + if (register_framebuffer(&info) < 0) + return -EINVAL; + printk(KERN_INFO "fb%d: %s frame buffer device\n", info.node, + info.fix.id); + return 0; +} + + /* + * Cleanup + */ + +static void __exit xxxfb_cleanup(void) +{ + /* + * If your driver supports multiple boards, you should unregister and + * clean up all instances. + */ + + unregister_framebuffer(info); + fb_dealloc_cmap(&info.cmap); + /* ... */ +} + + /* + * 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, /* Needed !!! */ + .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"); |