Small summary of capebus. Signed-off-by: Pantelis Antoniou <panto@xxxxxxxxxxxxxxxxxxxxxxx> --- Documentation/capebus/capebus-summary | 40 +++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 Documentation/capebus/capebus-summary diff --git a/Documentation/capebus/capebus-summary b/Documentation/capebus/capebus-summary new file mode 100644 index 0000000..742e33c --- /dev/null +++ b/Documentation/capebus/capebus-summary @@ -0,0 +1,40 @@ +Overview of Linux kernel Capebus support +======================================== + +30-Oct-2012 + +What is Capebus? +---------------- +Capebus is an abstract concept. There's no such thing as a vanilla physical +capebus, what is there is a concept and a method on how various capebus +based implementations can be made. + +Capebus is created to address the problem of many SoCs that can provide a +multitude of hardware interfaces but in order to keep costs down the main +boards only support a limited number of them. The rest are typically brought +out to pin connectors on to which other boards, named capes are connected and +allow those peripherals to be used. + +These capes connect to the SoC interfaces but might also contain various other +parts that may need some kind of driver to work. + +Since SoCs have limited pins and pin muxing options, not all capes can work +together so some kind of resource tracking (at least for the pins in use) is +required. + +Before capebus all of this took place in the board support file, and frankly +for boards with too many capes it was becoming unmanageable. + +Capebus provides a virtual bus, which along with a board specific controller, +cape drivers can be written using the standard Linux device model. + +What kind of systems/boards capebus supports? +--------------------------------------------- + +The core capebus infrastructure is not depended on any specific board. +However capebus needs a board controller to provide services to the cape devices +it controls. Services like addressing and resource reservation are provided +by the board controller. + +Capebus at the moment only support TI's Beaglebone platform. + -- 1.7.12 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
