Merge tag 'docs-5.3' of git://git.lwn.net/linux

Pull Documentation updates from Jonathan Corbet:
 "It's been a relatively busy cycle for docs:

   - A fair pile of RST conversions, many from Mauro. These create more
     than the usual number of simple but annoying merge conflicts with
     other trees, unfortunately. He has a lot more of these waiting on
     the wings that, I think, will go to you directly later on.

   - A new document on how to use merges and rebases in kernel repos,
     and one on Spectre vulnerabilities.

   - Various improvements to the build system, including automatic
     markup of function() references because some people, for reasons I
     will never understand, were of the opinion that
     :c:func:``function()`` is unattractive and not fun to type.

   - We now recommend using sphinx 1.7, but still support back to 1.4.

   - Lots of smaller improvements, warning fixes, typo fixes, etc"

* tag 'docs-5.3' of git://git.lwn.net/linux: (129 commits)
  docs: automarkup.py: ignore exceptions when seeking for xrefs
  docs: Move binderfs to admin-guide
  Disable Sphinx SmartyPants in HTML output
  doc: RCU callback locks need only _bh, not necessarily _irq
  docs: format kernel-parameters -- as code
  Doc : doc-guide : Fix a typo
  platform: x86: get rid of a non-existent document
  Add the RCU docs to the core-api manual
  Documentation: RCU: Add TOC tree hooks
  Documentation: RCU: Rename txt files to rst
  Documentation: RCU: Convert RCU UP systems to reST
  Documentation: RCU: Convert RCU linked list to reST
  Documentation: RCU: Convert RCU basic concepts to reST
  docs: filesystems: Remove uneeded .rst extension on toctables
  scripts/sphinx-pre-install: fix out-of-tree build
  docs: zh_CN: submitting-drivers.rst: Remove a duplicated Documentation/
  Documentation: PGP: update for newer HW devices
  Documentation: Add section about CPU vulnerabilities for Spectre
  Documentation: platform: Delete x86-laptop-drivers.txt
  docs: Note that :c:func: should no longer be used
  ...

1 files changed, 140 insertions, 0 deletions

diff --git a/Documentation/fb/ep93xx-fb.rst b/Documentation/fb/ep93xx-fb.rst
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+================================
+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.rst 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.