diff options
| -rw-r--r-- | drivers/video/skeletonfb.c | 482 |
1 files changed, 383 insertions, 99 deletions
diff --git a/drivers/video/skeletonfb.c b/drivers/video/skeletonfb.c index a01e7ecc15ed..9b707771d757 100644 --- a/drivers/video/skeletonfb.c +++ b/drivers/video/skeletonfb.c @@ -115,7 +115,8 @@ static struct fb_fix_screeninfo xxxfb_fix __initdata = { /* * If your driver supports multiple boards or it supports multiple * framebuffers, you should make these arrays, or allocate them - * dynamically (using kmalloc()). + * dynamically using framebuffer_alloc() and free them with + * framebuffer_release(). */ static struct fb_info info; @@ -179,18 +180,31 @@ static int xxxfb_release(const struct fb_info *info, int user) * 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. + * 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) { - const struct xxx_par *par = (const struct xxx_par *) info->par; /* ... */ return 0; } @@ -204,14 +218,39 @@ static int xxxfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info) * 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. + * + * 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 = (struct xxx_par *) info->par; + struct xxx_par *par = info->par; /* ... */ return 0; } @@ -258,70 +297,110 @@ static int xxxfb_setcolreg(unsigned regno, unsigned red, unsigned green, * 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) + * 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: - * 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) + * 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 - * cmap is programmed to (red << red.offset) | (green << green.offset) | - * (blue << blue.offset) | (transp << transp.offset) + * 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) - 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; - } + 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 - /* 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; + /* + * 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; } @@ -340,6 +419,17 @@ static int xxxfb_setcolreg(unsigned regno, unsigned red, unsigned green, 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; } @@ -349,15 +439,20 @@ static int xxxfb_pan_display(struct fb_var_screeninfo *var, * @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 + * 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. * - * Returns negative errno on error, or zero on success. + * 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) @@ -454,6 +549,14 @@ void xxxfb_imageblit(struct fb_info *p, const struct fb_image *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. + */ } /** @@ -517,6 +620,7 @@ int xxxfb_cursor(struct fb_info *info, struct fb_cursor *cursor) */ void xxxfb_rotate(struct fb_info *info, int angle) { +/* Will be deprecated */ } /** @@ -540,6 +644,9 @@ void xxxfb_poll(struct fb_info *info, poll_table *wait) * 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) { @@ -549,20 +656,25 @@ void xxxfb_sync(struct fb_info *info) * Initialization */ -int __init xxxfb_init(void) +/* 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; /* - * For kernel boot options (in 'video=xxxfb:<options>' format) + * Dynamically allocate info and par */ -#ifndef MODULE - char *option = NULL; + info = framebuffer_alloc(sizeof(struct xxx_par), device); - if (fb_get_options("xxxfb", &option)) - return -ENODEV; - xxxfb_setup(option); -#endif + if (!info) { + /* goto error path */ + } + + par = info->par; /* * Here we set the screen_base to the virtual memory address @@ -570,18 +682,87 @@ int __init xxxfb_init(void) * 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; - + 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.flags = FBINFO_DEFAULT; - info.par = current_par; + 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 @@ -590,42 +771,145 @@ int __init xxxfb_init(void) if (!mode_option) mode_option = "640x480@60"; - retval = fb_find_mode(&info.var, &info, mode_option, NULL, 0, NULL, 8); + 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); + 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) + 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); + 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; +} -static void __exit xxxfb_cleanup(void) +#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) { - /* - * If your driver supports multiple boards, you should unregister and - * clean up all instances. - */ + /* + * For kernel boot options (in 'video=xxxfb:<options>' format) + */ +#ifndef MODULE + char *option = NULL; - unregister_framebuffer(info); - fb_dealloc_cmap(&info.cmap); - /* ... */ + 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 + +MODULE_LICENSE("GPL"); +module_init(xxxfb_init); +module_exit(xxxfb_exit); + /* * Setup |