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author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-01-20 14:01:31 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-01-20 14:01:31 -0300 |
commit | b4b7ff4b08e691656c9d77c758fc355833128ac0 (patch) | |
tree | 82fcb00e6b918026dc9f2d1f05ed8eee83874cc0 /Documentation/arm/keystone | |
parent | 35acfa0fc609f2a2cd95cef4a6a9c3a5c38f1778 (diff) |
Linux-libre 4.4-gnupck-4.4-gnu
Diffstat (limited to 'Documentation/arm/keystone')
-rw-r--r-- | Documentation/arm/keystone/Overview.txt | 18 | ||||
-rw-r--r-- | Documentation/arm/keystone/knav-qmss.txt | 35 |
2 files changed, 35 insertions, 18 deletions
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 <m-karicheri2@ti.com> 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)*/ |