From b4b7ff4b08e691656c9d77c758fc355833128ac0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 20 Jan 2016 14:01:31 -0300 Subject: Linux-libre 4.4-gnu --- Documentation/arm/keystone/Overview.txt | 18 ---------------- Documentation/arm/keystone/knav-qmss.txt | 35 ++++++++++++++++++++++++++++++++ 2 files changed, 35 insertions(+), 18 deletions(-) create mode 100644 Documentation/arm/keystone/knav-qmss.txt (limited to 'Documentation/arm/keystone') diff --git a/Documentation/arm/keystone/Overview.txt b/Documentation/arm/keystone/Overview.txt index f17bc4c9d..400c0c270 100644 --- a/Documentation/arm/keystone/Overview.txt +++ b/Documentation/arm/keystone/Overview.txt @@ -49,24 +49,6 @@ specified through DTS. Following are the DTS used:- The device tree documentation for the keystone machines are located at Documentation/devicetree/bindings/arm/keystone/keystone.txt -Known issues & workaround -------------------------- - -Some of the device drivers used on keystone are re-used from that from -DaVinci and other TI SoCs. These device drivers may use clock APIs directly. -Some of the keystone specific drivers such as netcp uses run time power -management API instead to enable clock. As this API has limitations on -keystone, following workaround is needed to boot Linux. - - Add 'clk_ignore_unused' to the bootargs env variable in u-boot. Otherwise - clock frameworks will try to disable clocks that are unused and disable - the hardware. This is because netcp related power domain and clock - domains are enabled in u-boot as run time power management API currently - doesn't enable clocks for netcp due to a limitation. This workaround is - expected to be removed in the future when proper API support becomes - available. Until then, this work around is needed. - - Document Author --------------- Murali Karicheri diff --git a/Documentation/arm/keystone/knav-qmss.txt b/Documentation/arm/keystone/knav-qmss.txt new file mode 100644 index 000000000..d119e0236 --- /dev/null +++ b/Documentation/arm/keystone/knav-qmss.txt @@ -0,0 +1,35 @@ +* Texas Instruments Keystone Navigator Queue Management SubSystem driver + +Driver source code path + drivers/soc/ti/knav_qmss.c + drivers/soc/ti/knav_qmss_acc.c + +The QMSS (Queue Manager Sub System) found on Keystone SOCs is one of +the main hardware sub system which forms the backbone of the Keystone +multi-core Navigator. QMSS consist of queue managers, packed-data structure +processors(PDSP), linking RAM, descriptor pools and infrastructure +Packet DMA. +The Queue Manager is a hardware module that is responsible for accelerating +management of the packet queues. Packets are queued/de-queued by writing or +reading descriptor address to a particular memory mapped location. The PDSPs +perform QMSS related functions like accumulation, QoS, or event management. +Linking RAM registers are used to link the descriptors which are stored in +descriptor RAM. Descriptor RAM is configurable as internal or external memory. +The QMSS driver manages the PDSP setups, linking RAM regions, +queue pool management (allocation, push, pop and notify) and descriptor +pool management. + +knav qmss driver provides a set of APIs to drivers to open/close qmss queues, +allocate descriptor pools, map the descriptors, push/pop to queues etc. For +details of the available APIs, please refers to include/linux/soc/ti/knav_qmss.h + +DT documentation is available at +Documentation/devicetree/bindings/soc/ti/keystone-navigator-qmss.txt + +Accumulator QMSS queues using PDSP firmware +============================================ +The QMSS PDSP firmware support accumulator channel that can monitor a single +queue or multiple contiguous queues. drivers/soc/ti/knav_qmss_acc.c is the +driver that interface with the accumulator PDSP. This configures +accumulator channels defined in DTS (example in DT documentation) to monitor +1 or 32 queues per channel. /*(DEBLOBBED)*/ -- cgit v1.2.3-54-g00ecf