The patch titled
SM501: Add Documentation/SM501.txt
has been added to the -mm tree. Its filename is
sm501-add-documentation-sm501txt.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: SM501: Add Documentation/SM501.txt
From: Ben Dooks <ben-linux@xxxxxxxxx>
Add documentation for the SM501 in Documentation/SM501.txt outlining the SM501
driver.
Signed-off-by: Ben Dooks <ben-linux@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/SM501.txt | 66 ++++++++++++++++++++++++++++++++++++++
1 files changed, 66 insertions(+)
diff -puN /dev/null Documentation/SM501.txt
--- /dev/null
+++ a/Documentation/SM501.txt
@@ -0,0 +1,66 @@
+ SM501 Driver
+ ============
+
+Copyright 2006, 2007 Simtec Electronics
+
+Core
+----
+
+The core driver in drivers/mfd provides common services for the
+drivers which manage the specific hardware blocks. These services
+include locking for common registers, clock control and resource
+management.
+
+The core registers drivers for both PCI and generic bus based
+chips via the platform device and driver system.
+
+On detection of a device, the core initialises the chip (which may
+be specified by the platform data) and then exports the selected
+peripheral set as platform devices for the specific drivers.
+
+The core re-uses the platform device system as the platform device
+system provides enough features to support the drivers without the
+need to create a new bus-type and the associated code to go with it.
+
+
+Resources
+---------
+
+Each peripheral has a view of the device which is implicitly narrowed to
+the specific set of resources that peripheral requires in order to
+function correctly.
+
+The centralised memory allocation allows the driver to ensure that the
+maximum possible resource allocation can be made to the video subsystem
+as this is by-far the most resource-sensitive of the on-chip functions.
+
+The primary issue with memory allocation is that of moving the video
+buffers once a display mode is chosen. Indeed when a video mode change
+occurs the memory footprint of the video subsystem changes.
+
+Since video memory is difficult to move without changing the display
+(unless sufficient contiguous memory can be provided for the old and new
+modes simultaneously) the video driver fully utilises the memory area
+given to it by aligning fb0 to the start of the area and fb1 to the end
+of it. Any memory left over in the middle is used for the acceleration
+functions, which are transient and thus their location is less critical
+as it can be moved.
+
+
+Configuration
+-------------
+
+The platform device driver uses a set of platform data to pass
+configurations through to the core and the subsidiary drivers
+so that there can be support for more than one system carrying
+an SM501 built into a single kernel image.
+
+The PCI driver assumes that the PCI card behaves as per the Silicon
+Motion reference design.
+
+There is an errata (AB-5) affecting the selection of the
+of the M1XCLK and M1CLK frequencies. These two clocks
+must be sourced from the same PLL, although they can then
+be divided down individually. If this is not set, then SM501 may
+lock and hang the whole system. The driver will refuse to
+attach if the PLL selection is different.
_
Patches currently in -mm which might be from ben-linux@xxxxxxxxx are
spi-tle620x-power-switch-driver.patch
sm501-suspend-support.patch
sm501-suspend-support-fix.patch
sm501-initialise-sdram-clock-before-bus-clocks.patch
sm501-fix-sm501_init_reg-mask-set-order.patch
sm501-clock-updates-and-checks.patch
sm501-clock-updates-and-checks-fix.patch
sm501-add-documentation-sm501txt.patch
sm501-check-sm501-id-register-on-initialisation.patch
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