diff options
author | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-06-27 21:39:22 +0300 |
---|---|---|
committer | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-07-15 17:03:02 +0300 |
commit | baa293e9544bea71361950d071579f0e4d5713ed (patch) | |
tree | 29e0400c806016783a3fd7a380be40a201956653 /Documentation/SM501.txt | |
parent | 4f4cfa6c560c93ba180c30675cf845e1597de44c (diff) | |
download | linux-baa293e9544bea71361950d071579f0e4d5713ed.tar.xz |
docs: driver-api: add a series of orphaned documents
There are lots of documents under Documentation/*.txt and a few other
orphan documents elsehwere that belong to the driver-API book.
Move them to their right place.
Reviewed-by: Cornelia Huck <cohuck@redhat.com> # vfio-related parts
Acked-by: Logan Gunthorpe <logang@deltatee.com> # switchtec
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Diffstat (limited to 'Documentation/SM501.txt')
-rw-r--r-- | Documentation/SM501.txt | 74 |
1 files changed, 0 insertions, 74 deletions
diff --git a/Documentation/SM501.txt b/Documentation/SM501.txt deleted file mode 100644 index 882507453ba4..000000000000 --- a/Documentation/SM501.txt +++ /dev/null @@ -1,74 +0,0 @@ -.. include:: <isonum.txt> - -============ -SM501 Driver -============ - -:Copyright: |copy| 2006, 2007 Simtec Electronics - -The Silicon Motion SM501 multimedia companion chip is a multifunction device -which may provide numerous interfaces including USB host controller USB gadget, -asynchronous serial ports, audio functions, and a dual display video interface. -The device may be connected by PCI or local bus with varying functions enabled. - -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. |