new file mode 100644
@@ -0,0 +1,136 @@
+===========================
+ASPEED Interrupt Controller
+===========================
+
+AST2700
+-------
+There are a total of 480 interrupt sources in AST2700. Due to the limitation of
+interrupt numbers of processors, the interrupts are merged every 32 sources for
+interrupt numbers greater than 127.
+
+There are two levels of interrupt controllers, INTC (CPU Die) and INTCIO
+(I/O Die).
+
+Interrupt Mapping
+-----------------
+- INTC: Handles interrupt sources 0 - 127 and integrates signals from INTCIO.
+- INTCIO: Handles interrupt sources 128 - 319 independently.
+
+QEMU Support
+------------
+Currently, only GIC 192 to 201 are supported, and their source interrupts are
+from INTCIO and connected to INTC at input pin 0 and output pins 0 to 9 for
+GIC 192-201.
+
+Design for GICINT 196
+---------------------
+The orgate has interrupt sources ranging from 0 to 31, with its output pin
+connected to INTCIO "T0 GICINT_196". The output pin is then connected to INTC
+"GIC_192_201" at bit 4, and its bit 4 output pin is connected to GIC 196.
+
+INTC GIC_192_201 Output Pin Mapping
+-----------------------------------
+The design of INTC GIC_192_201 have 10 output pins, mapped as following:
+
+==== ====
+Bit GIC
+==== ====
+0 192
+1 193
+2 194
+3 195
+4 196
+5 197
+6 198
+7 199
+8 200
+9 201
+==== ====
+
+AST2700 A0
+----------
+It has only one INTC controller, and currently, only GIC 128-136 is supported.
+To support both AST2700 A1 and AST2700 A0, there are 10 OR gates in the INTC,
+with gates 1 to 9 supporting GIC 128-136.
+
+Design for GICINT 132
+---------------------
+The orgate has interrupt sources ranging from 0 to 31, with its output pin
+connected to INTC. The output pin is then connected to GIC 132.
+
+Block Diagram of GICINT 196 for AST2700 A1 and GICINT 132 for AST2700 A0
+------------------------------------------------------------------------
+
+.. code-block::
+
+ |-------------------------------------------------------------------------------------------------------|
+ | AST2700 A1 Design |
+ | To GICINT196 |
+ | |
+ | ETH1 |-----------| |--------------------------| |--------------| |
+ | -------->|0 | | INTCIO | | orgates[0] | |
+ | ETH2 | 4| orgates[0]------>|inpin[0]-------->outpin[0]|------->| 0 | |
+ | -------->|1 5| orgates[1]------>|inpin[1]-------->outpin[1]|------->| 1 | |
+ | ETH3 | 6| orgates[2]------>|inpin[2]-------->outpin[2]|------->| 2 | |
+ | -------->|2 19| orgates[3]------>|inpin[3]-------->outpin[3]|------->| 3 OR[0:9] |-----| |
+ | UART0 | 20|-->orgates[4]------>|inpin[4]-------->outpin[4]|------->| 4 | | |
+ | -------->|7 21| orgates[5]------>|inpin[5]-------->outpin[5]|------->| 5 | | |
+ | UART1 | 22| orgates[6]------>|inpin[6]-------->outpin[6]|------->| 6 | | |
+ | -------->|8 23| orgates[7]------>|inpin[7]-------->outpin[7]|------->| 7 | | |
+ | UART2 | 24| orgates[8]------>|inpin[8]-------->outpin[8]|------->| 8 | | |
+ | -------->|9 25| orgates[9]------>|inpin[9]-------->outpin[9]|------->| 9 | | |
+ | UART3 | 26| |--------------------------| |--------------| | |
+ | ---------|10 27| | |
+ | UART5 | 28| | |
+ | -------->|11 29| | |
+ | UART6 | | | |
+ | -------->|12 30| |-----------------------------------------------------------------------| |
+ | UART7 | 31| | |
+ | -------->|13 | | |
+ | UART8 | OR[0:31] | | |------------------------------| |----------| |
+ | -------->|14 | | | INTC | | GIC | |
+ | UART9 | | | |inpin[0:0]--------->outpin[0] |---------->|192 | |
+ | -------->|15 | | |inpin[0:1]--------->outpin[1] |---------->|193 | |
+ | UART10 | | | |inpin[0:2]--------->outpin[2] |---------->|194 | |
+ | -------->|16 | | |inpin[0:3]--------->outpin[3] |---------->|195 | |
+ | UART11 | | |--------------> |inpin[0:4]--------->outpin[4] |---------->|196 | |
+ | -------->|17 | |inpin[0:5]--------->outpin[5] |---------->|197 | |
+ | UART12 | | |inpin[0:6]--------->outpin[6] |---------->|198 | |
+ | -------->|18 | |inpin[0:7]--------->outpin[7] |---------->|199 | |
+ | |-----------| |inpin[0:8]--------->outpin[8] |---------->|200 | |
+ | |inpin[0:9]--------->outpin[9] |---------->|201 | |
+ |-------------------------------------------------------------------------------------------------------|
+ |-------------------------------------------------------------------------------------------------------|
+ | ETH1 |-----------| orgates[1]------->|inpin[1]----------->outpin[10]|---------->|128 | |
+ | -------->|0 | orgates[2]------->|inpin[2]----------->outpin[11]|---------->|129 | |
+ | ETH2 | 4| orgates[3]------->|inpin[3]----------->outpin[12]|---------->|130 | |
+ | -------->|1 5| orgates[4]------->|inpin[4]----------->outpin[13]|---------->|131 | |
+ | ETH3 | 6|---->orgates[5]------->|inpin[5]----------->outpin[14]|---------->|132 | |
+ | -------->|2 19| orgates[6]------->|inpin[6]----------->outpin[15]|---------->|133 | |
+ | UART0 | 20| orgates[7]------->|inpin[7]----------->outpin[16]|---------->|134 | |
+ | -------->|7 21| orgates[8]------->|inpin[8]----------->outpin[17]|---------->|135 | |
+ | UART1 | 22| orgates[9]------->|inpin[9]----------->outpin[18]|---------->|136 | |
+ | -------->|8 23| |------------------------------| |----------| |
+ | UART2 | 24| |
+ | -------->|9 25| AST2700 A0 Design |
+ | UART3 | 26| |
+ | -------->|10 27| |
+ | UART5 | 28| |
+ | -------->|11 29| GICINT132 |
+ | UART6 | | |
+ | -------->|12 30| |
+ | UART7 | 31| |
+ | -------->|13 | |
+ | UART8 | OR[0:31] | |
+ | -------->|14 | |
+ | UART9 | | |
+ | -------->|15 | |
+ | UART10 | | |
+ | -------->|16 | |
+ | UART11 | | |
+ | -------->|17 | |
+ | UART12 | | |
+ | -------->|18 | |
+ | |-----------| |
+ | |
+ |-------------------------------------------------------------------------------------------------------|
@@ -38,3 +38,4 @@ guest hardware that is specific to QEMU.
rocker
riscv-iommu
riscv-aia
+ aspeed-intc
Add AST2700 INTC design guidance and its block diagram. Signed-off-by: Jamin Lin <jamin_lin@aspeedtech.com> --- docs/specs/aspeed-intc.rst | 136 +++++++++++++++++++++++++++++++++++++ docs/specs/index.rst | 1 + 2 files changed, 137 insertions(+) create mode 100644 docs/specs/aspeed-intc.rst