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Diffstat (limited to 'Documentation/fb/ep93xx-fb.txt')
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diff --git a/Documentation/fb/ep93xx-fb.txt b/Documentation/fb/ep93xx-fb.txt deleted file mode 100644 index 5af1bd9effae..000000000000 --- a/Documentation/fb/ep93xx-fb.txt +++ /dev/null @@ -1,135 +0,0 @@ -================================ -Driver for EP93xx LCD controller -================================ - -The EP93xx LCD controller can drive both standard desktop monitors and -embedded LCD displays. If you have a standard desktop monitor then you -can use the standard Linux video mode database. In your board file: - - static struct ep93xxfb_mach_info some_board_fb_info = { - .num_modes = EP93XXFB_USE_MODEDB, - .bpp = 16, - }; - -If you have an embedded LCD display then you need to define a video -mode for it as follows: - - static struct fb_videomode some_board_video_modes[] = { - { - .name = "some_lcd_name", - /* Pixel clock, porches, etc */ - }, - }; - -Note that the pixel clock value is in pico-seconds. You can use the -KHZ2PICOS macro to convert the pixel clock value. Most other values -are in pixel clocks. See Documentation/fb/framebuffer.txt for further -details. - -The ep93xxfb_mach_info structure for your board should look like the -following: - - static struct ep93xxfb_mach_info some_board_fb_info = { - .num_modes = ARRAY_SIZE(some_board_video_modes), - .modes = some_board_video_modes, - .default_mode = &some_board_video_modes[0], - .bpp = 16, - }; - -The framebuffer device can be registered by adding the following to -your board initialisation function: - - ep93xx_register_fb(&some_board_fb_info); - -===================== -Video Attribute Flags -===================== - -The ep93xxfb_mach_info structure has a flags field which can be used -to configure the controller. The video attributes flags are fully -documented in section 7 of the EP93xx users' guide. The following -flags are available: - -EP93XXFB_PCLK_FALLING Clock data on the falling edge of the - pixel clock. The default is to clock - data on the rising edge. - -EP93XXFB_SYNC_BLANK_HIGH Blank signal is active high. By - default the blank signal is active low. - -EP93XXFB_SYNC_HORIZ_HIGH Horizontal sync is active high. By - default the horizontal sync is active low. - -EP93XXFB_SYNC_VERT_HIGH Vertical sync is active high. By - default the vertical sync is active high. - -The physical address of the framebuffer can be controlled using the -following flags: - -EP93XXFB_USE_SDCSN0 Use SDCSn[0] for the framebuffer. This - is the default setting. - -EP93XXFB_USE_SDCSN1 Use SDCSn[1] for the framebuffer. - -EP93XXFB_USE_SDCSN2 Use SDCSn[2] for the framebuffer. - -EP93XXFB_USE_SDCSN3 Use SDCSn[3] for the framebuffer. - -================== -Platform callbacks -================== - -The EP93xx framebuffer driver supports three optional platform -callbacks: setup, teardown and blank. The setup and teardown functions -are called when the framebuffer driver is installed and removed -respectively. The blank function is called whenever the display is -blanked or unblanked. - -The setup and teardown devices pass the platform_device structure as -an argument. The fb_info and ep93xxfb_mach_info structures can be -obtained as follows: - - static int some_board_fb_setup(struct platform_device *pdev) - { - struct ep93xxfb_mach_info *mach_info = pdev->dev.platform_data; - struct fb_info *fb_info = platform_get_drvdata(pdev); - - /* Board specific framebuffer setup */ - } - -====================== -Setting the video mode -====================== - -The video mode is set using the following syntax: - - video=XRESxYRES[-BPP][@REFRESH] - -If the EP93xx video driver is built-in then the video mode is set on -the Linux kernel command line, for example: - - video=ep93xx-fb:800x600-16@60 - -If the EP93xx video driver is built as a module then the video mode is -set when the module is installed: - - modprobe ep93xx-fb video=320x240 - -============== -Screenpage bug -============== - -At least on the EP9315 there is a silicon bug which causes bit 27 of -the VIDSCRNPAGE (framebuffer physical offset) to be tied low. There is -an unofficial errata for this bug at: - http://marc.info/?l=linux-arm-kernel&m=110061245502000&w=2 - -By default the EP93xx framebuffer driver checks if the allocated physical -address has bit 27 set. If it does, then the memory is freed and an -error is returned. The check can be disabled by adding the following -option when loading the driver: - - ep93xx-fb.check_screenpage_bug=0 - -In some cases it may be possible to reconfigure your SDRAM layout to -avoid this bug. See section 13 of the EP93xx users' guide for details. |