[PATCH 4/5] Documentation: misc-devices: Add Documentation for dw-xdata-pcie driver

[Gustavo Pimentel]

Add Documentation for dw-xdata-pcie driver.

Signed-off-by: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
---
 Documentation/misc-devices/dw-xdata-pcie.rst | 43 ++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)
 create mode 100644 Documentation/misc-devices/dw-xdata-pcie.rst

diff --git a/Documentation/misc-devices/dw-xdata-pcie.rst b/Documentation/misc-devices/dw-xdata-pcie.rst
new file mode 100644
index 00000000..4d4616e
--- /dev/null
+++ b/Documentation/misc-devices/dw-xdata-pcie.rst
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+.. SPDX-License-Identifier: GPL-2.0
+
+===========================================================================w
+Driver for Synopsys DesignWare PCIe traffic generator (also known as xData)
+===========================================================================
+
+This driver should be used as a host-side (Root Complex) driver and Synopsys
+DesignWare prototype that includes this IP.
+
+The "dw-xdata-pcie" driver can be used to enable/disable PCIe traffic
+generator in either direction (mutual exclusion) besides allowing the
+PCIe link performance analysis.
+
+The interaction with this driver is done through the module parameter and
+can be changed in runtime. The driver outputs the requested command state
+information to /var/log/kern.log or dmesg.
+
+Request write TLPs traffic generation - Root Complex to Endpoint direction
+- Command:
+	echo w > /sys/module/dw_xdata_pcie/parameters/command
+- Output example:
+	dw-xdata-pcie 0000:01.0: xData: requested write transfer
+	dw-xdata-pcie 0000:01.0: xData: started write direction
+
+Request read TLPs traffic generation - Endpoint to Root Complex direction:
+- Command:
+	echo r > /sys/module/dw_xdata_pcie/parameters/command
+- Output example:
+	dw-xdata-pcie 0000:01.0: xData: requested read transfer
+	dw-xdata-pcie 0000:01.0: xData: started read direction
+
+Request to stop any current TLP transfer:
+- Command:
+	echo s > /sys/module/dw_xdata_pcie/parameters/command
+- Output example:
+	dw-xdata-pcie 0000:01.0: xData: requested stop any transfer
+
+Request PCIe link performance analysis:
+- Command:
+	echo p > /sys/module/dw_xdata_pcie/parameters/command
+   - Output example:
+	dw-xdata-pcie 0000:01.0: xData: requested performance analysis
+	dw-xdata-pcie 0000:01.0: xData: time=112000000us, read=0 MB/s, write=0 MB/s
-- 
2.7.4