[PATCH v2] docs: fusa: Add requirements for emulated uart

[Ayan Kumar Halder <ayan.kumar.halder@xxxxxxx>]

From: Michal Orzel <michal.orzel@xxxxxxx>

Add the requirements for emulated SBSA UART.

Signed-off-by: Michal Orzel <michal.orzel@xxxxxxx>
Signed-off-by: Ayan Kumar Halder <ayan.kumar.halder@xxxxxxx>
---
Changes from :-

v1 - 1. Reworded the requirements to remove any ambiguity.
2. Dopped the "virtualization unaware VMs" requirement as it is not easy to
define "virtualization unaware".

 .../fusa/reqs/design-reqs/arm64/sbsa-uart.rst | 224 ++++++++++++++++++
 docs/fusa/reqs/market-reqs/reqs.rst           |  15 ++
 docs/fusa/reqs/product-reqs/arm64/reqs.rst    |  19 ++
 3 files changed, 258 insertions(+)
 create mode 100644 docs/fusa/reqs/design-reqs/arm64/sbsa-uart.rst

diff --git a/docs/fusa/reqs/design-reqs/arm64/sbsa-uart.rst 
b/docs/fusa/reqs/design-reqs/arm64/sbsa-uart.rst
new file mode 100644
index 0000000000..89598fa8a5
--- /dev/null
+++ b/docs/fusa/reqs/design-reqs/arm64/sbsa-uart.rst
@@ -0,0 +1,224 @@
+.. SPDX-License-Identifier: CC-BY-4.0
+
+SBSA UART
+=========
+
+The following are the requirements related to SBSA UART [1] emulated and
+exposed by Xen to Arm64 domains.
+
+Probe the UART device tree node from a domain
+---------------------------------------------
+
+`XenSwdgn~arm64_uart_probe_dt~1`
+
+Description:
+Xen shall generate a device tree node for the SBSA UART (in accordance to Arm
+SBSA UART device tree binding [2]) in the domain device tree.
+
+Rationale:
+
+Comments:
+Domains can detect the presence of the SBSA UART device tree node.
+
+Covers:
+ - `XenProd~emulated_uart~1`
+
+Transmit data in software polling mode
+--------------------------------------
+
+`XenSwdgn~arm64_uart_transmit_data_poll_mode~1`
+
+Description:
+Xen shall support transmission of data in polling mode.
+
+Rationale:
+
+Comments:
+
+Covers:
+ - `XenProd~emulated_uart~1`
+
+Transmit data in interrupt driven mode
+--------------------------------------
+
+`XenSwdgn~arm64_uart_transmit_data_interrupt_mode~1`
+
+Description:
+Xen shall support transmission of data in interrupt driven mode.
+
+Rationale:
+
+Comments:
+
+Covers:
+ - `XenProd~emulated_uart~1`
+
+Receive data in software polling mode
+-------------------------------------
+
+`XenSwdgn~arm64_uart_receive_data_polling_mode~1`
+
+Description:
+Xen shall support reception of data in polling mode.
+
+Rationale:
+
+Comments:
+
+Covers:
+ - `XenProd~emulated_uart~1`
+
+Receive data in interrupt driven mode
+-------------------------------------
+
+`XenSwdgn~arm64_uart_receive_data_interrupt_mode~1`
+
+Description:
+Xen shall support reception of data in interrupt driven mode.
+
+Rationale:
+
+Comments:
+
+Covers:
+ - `XenProd~emulated_uart~1`
+
+Access UART data register
+-------------------------
+
+`XenSwdgn~arm64_uart_access_data_register~1`
+
+Description:
+Xen shall emulate the UARTDR register.
+
+Rationale:
+
+Comments:
+
+Covers:
+ - `XenProd~emulated_uart~1`
+
+Access UART receive status register
+-----------------------------------
+
+`XenSwdgn~arm64_uart_access_receive_status_register~1`
+
+Description:
+Xen shall emulate the UARTRSR register.
+
+Rationale:
+
+Comments:
+
+Covers:
+ - `XenProd~emulated_uart~1`
+
+Access UART flag register
+-------------------------
+
+`XenSwdgn~arm64_uart_access_flag_register~1`
+
+Description:
+Xen shall emulate the UARTFR register.
+
+Rationale:
+
+Comments:
+
+Covers:
+ - `XenProd~emulated_uart~1`
+
+Access UART mask set/clear register
+-----------------------------------
+
+`XenSwdgn~arm64_uart_access_mask_register~1`
+
+Description:
+Xen shall emulate the UARTIMSC register.
+
+Rationale:
+
+Comments:
+
+Covers:
+ - `XenProd~emulated_uart~1`
+
+Access UART raw interrupt status register
+-----------------------------------------
+
+`XenSwdgn~arm64_uart_access_raw_interrupt_status_register~1`
+
+Description:
+Xen shall emulate the UARTRIS register.
+
+Rationale:
+
+Comments:
+
+Covers:
+ - `XenProd~emulated_uart~1`
+
+Access UART masked interrupt status register
+--------------------------------------------
+
+`XenSwdgn~arm64_uart_access_mask_irq_status_register~1`
+
+Description:
+Xen shall emulate the UARTMIS register.
+
+Rationale:
+
+Comments:
+
+Covers:
+ - `XenProd~emulated_uart~1`
+
+Access UART interrupt clear register
+------------------------------------
+
+`XenSwdgn~arm64_uart_access_irq_clear_register~1`
+
+Description:
+Xen shall emulate the UARTICR register.
+
+Rationale:
+
+Comments:
+
+Covers:
+ - `XenProd~emulated_uart~1`
+
+Receive UART TX interrupt
+-------------------------
+
+`XenSwdgn~arm64_uart_receive_tx_irq~1`
+
+Description:
+Xen shall generate UART interrupt when the UART transmit interrupt condition is
+met.
+
+Rationale:
+
+Comments:
+
+Covers:
+ - `XenProd~emulated_uart~1`
+
+Receive UART RX interrupt reception
+-----------------------------------
+
+`XenSwdgn~arm64_uart_receive_rx_irq~1`
+
+Description:
+Xen shall generate UART interrupt when the UART receive interrupt condition is
+met.
+
+Rationale:
+
+Comments:
+
+Covers:
+ - `XenProd~emulated_uart~1`
+
+[1] Arm Base System Architecture, chapter B
+[2] 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/serial/arm_sbsa_uart.txt
\ No newline at end of file
diff --git a/docs/fusa/reqs/market-reqs/reqs.rst 
b/docs/fusa/reqs/market-reqs/reqs.rst
index 9c98c84a9a..e98f348cf4 100644
--- a/docs/fusa/reqs/market-reqs/reqs.rst
+++ b/docs/fusa/reqs/market-reqs/reqs.rst
@@ -32,3 +32,18 @@ Comments:
 
 Needs:
  - XenProd
+
+Provide console to the VMs
+--------------------------
+
+`XenMkt~provide_console_vms~1`
+
+Description:
+Xen shall provide a console to a VM.
+
+Rationale:
+
+Comments:
+
+Needs:
+ - XenProd
\ No newline at end of file
diff --git a/docs/fusa/reqs/product-reqs/arm64/reqs.rst 
b/docs/fusa/reqs/product-reqs/arm64/reqs.rst
index 7aa3eeab6a..97e90813ec 100644
--- a/docs/fusa/reqs/product-reqs/arm64/reqs.rst
+++ b/docs/fusa/reqs/product-reqs/arm64/reqs.rst
@@ -21,3 +21,22 @@ Covers:
 
 Needs:
  - XenSwdgn
+
+Emulated UART
+-------------
+
+`XenProd~emulated_uart~1`
+
+Description:
+Xen shall provide an "Arm SBSA UART" compliant device to the domains.
+
+Rationale:
+
+Comments:
+
+Covers:
+ - `XenMkt~run_arm64_vms~1`
+ - `XenMkt~provide_console_vms~1`
+
+Needs:
+ - XenSwdgn
\ No newline at end of file
-- 
2.25.1