From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@ppc970.osdl.org>
Date: Sat, 16 Apr 2005 15:20:36 -0700
Subject: Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
---
 Documentation/arm/Samsung-S3C24XX/Suspend.txt | 106 ++++++++++++++++++++++++++
 1 file changed, 106 insertions(+)
 create mode 100644 Documentation/arm/Samsung-S3C24XX/Suspend.txt

(limited to 'Documentation/arm/Samsung-S3C24XX/Suspend.txt')

diff --git a/Documentation/arm/Samsung-S3C24XX/Suspend.txt b/Documentation/arm/Samsung-S3C24XX/Suspend.txt
new file mode 100644
index 00000000000..e12bc3284a2
--- /dev/null
+++ b/Documentation/arm/Samsung-S3C24XX/Suspend.txt
@@ -0,0 +1,106 @@
+			S3C24XX Suspend Support
+			=======================
+
+
+Introduction
+------------
+
+  The S3C2410 supports a low-power suspend mode, where the SDRAM is kept
+  in Self-Refresh mode, and all but the essential peripheral blocks are
+  powered down. For more information on how this works, please look
+  at the S3C2410 datasheets from Samsung.
+
+
+Requirements
+------------
+
+  1) A bootloader that can support the necessary resume operation
+
+  2) Support for at least 1 source for resume
+
+  3) CONFIG_PM enabled in the kernel
+
+  4) Any peripherals that are going to be powered down at the same
+     time require suspend/resume support.
+
+
+Resuming
+--------
+
+  The S3C2410 user manual defines the process of sending the CPU to
+  sleep and how it resumes. The default behaviour of the Linux code
+  is to set the GSTATUS3 register to the physical address of the
+  code to resume Linux operation.
+
+  GSTATUS4 is currently left alone by the sleep code, and is free to
+  use for any other purposes (for example, the EB2410ITX uses this to
+  save memory configuration in).
+
+
+Machine Support
+---------------
+
+  The machine specific functions must call the s3c2410_pm_init() function
+  to say that its bootloader is capable of resuming. This can be as
+  simple as adding the following to the machine's definition:
+
+  INITMACHINE(s3c2410_pm_init)
+
+  A board can do its own setup before calling s3c2410_pm_init, if it
+  needs to setup anything else for power management support.
+
+  There is currently no support for over-riding the default method of
+  saving the resume address, if your board requires it, then contact
+  the maintainer and discuss what is required.
+
+  Note, the original method of adding an late_initcall() is wrong,
+  and will end up initialising all compiled machines' pm init!
+
+
+Debugging
+---------
+
+  There are several important things to remember when using PM suspend:
+
+  1) The uart drivers will disable the clocks to the UART blocks when
+     suspending, which means that use of printascii() or similar direct
+     access to the UARTs will cause the debug to stop.
+
+  2) Whilst the pm code itself will attempt to re-enable the UART clocks,
+     care should be taken that any external clock sources that the UARTs
+     rely on are still enabled at that point.
+
+
+Configuration
+-------------
+
+  The S3C2410 specific configuration in `System Type` defines various
+  aspects of how the S3C2410 suspend and resume support is configured
+
+  `S3C2410 PM Suspend debug`
+
+    This option prints messages to the serial console before and after
+    the actual suspend, giving detailed information on what is
+    happening
+
+
+  `S3C2410 PM Suspend Memory CRC`
+
+    Allows the entire memory to be checksummed before and after the
+    suspend to see if there has been any corruption of the contents.
+
+    This support requires the CRC32 function to be enabled.
+
+
+  `S3C2410 PM Suspend CRC Chunksize (KiB)`
+
+    Defines the size of memory each CRC chunk covers. A smaller value
+    will mean that the CRC data block will take more memory, but will
+    identify any faults with better precision
+
+
+Document Author
+---------------
+
+Ben Dooks, (c) 2004 Simtec Electronics
+
-- 
cgit v1.2.3