It's often useful during test, debug, and development to issue path
votes from shell. Add a debugfs client for this purpose.
Example usage:
cd /sys/kernel/debug/interconnect/test-client/
# Configure node endpoints for the path from CPU to DDR on
# qcom/sm8550.
echo chm_apps > src_node
echo ebi > dst_node
# Get path between src_node and dst_node. This is only
# necessary after updating the node endpoints.
echo 1 > get
# Set desired BW to 1GBps avg and 2GBps peak.
echo 1000000 > avg_bw
echo 2000000 > peak_bw
# Vote for avg_bw and peak_bw on the latest path from "get".
# Voting for multiple paths is possible by repeating this
# process for different nodes endpoints.
echo 1 > commit
Allowing userspace to directly enable and set bus rates can be dangerous
So, following in the footsteps of the regmap [0] and clk [1] frameworks,
keep these userspace controls compile-time disabled without Kconfig
options to enable them. Enabling this will require code changes to
define INTERCONNECT_ALLOW_WRITE_DEBUGFS.
[0] commit 09c6ecd394 ("regmap: Add support for writing to regmap registers via debugfs")
[1] commit 37215da555 ("clk: Add support for setting clk_rate via debugfs")
Signed-off-by: Mike Tipton <quic_mdtipton@quicinc.com>
Link: https://lore.kernel.org/r/20230807142914.12480-4-quic_mdtipton@quicinc.com
Signed-off-by: Georgi Djakov <djakov@kernel.org>
The interconnect graphs can be difficult to understand and the current
"interconnect_summary" file doesn't even display links in any way.
Add a new "interconnect_graph" file to debugfs in the graphviz "dot"
format which describes interconnect providers, nodes and links.
The file is human-readable and can be visualized by piping through
graphviz. Example:
ssh $TARGET cat /sys/kernel/debug/interconnect/interconnect_graph \
| dot -Tsvg > interconnect_graph.svg
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
This makes it consistent with the other headings in the Linux driver
implementer's API guide.
Signed-off-by: Louis Taylor <louis@kragniz.eu>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This is intended for Kernel hackers audience.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Reviewed-by: Georgi Djakov <georgi.djakov@linaro.org>
2019-07-15 09:20:28 -03:00
Renamed from Documentation/interconnect/interconnect.rst (Browse further)
