Commit Graph

6 Commits

Author SHA1 Message Date
Kuan-Wei Chiu
97b5266dac docs: interconnect: Document consumer APIs and drop outdated text
The documentation currently states that consumer interfaces are not
documented, which is no longer true.

Remove the outdated claim and include the existing kernel-doc from
drivers/interconnect/core.c (filtered for consumer APIs) and
drivers/interconnect/bulk.c.

Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20260312175341.2944154-3-visitorckw@gmail.com>
2026-03-17 08:51:28 -06:00
Kuan-Wei Chiu
6f600f9972 docs: interconnect: Add provider APIs to documentation
The "Interconnect providers" section currently only includes data
structures from include/linux/interconnect-provider.h.

Include drivers/interconnect/core.c to extract provider-specific
API documentation. The :functions: directive is used to prevent
mixing with consumer APIs.

Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20260312175341.2944154-2-visitorckw@gmail.com>
2026-03-17 08:51:28 -06:00
Mike Tipton
770c69f037 interconnect: Add debugfs test client
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>
2023-08-22 21:04:50 +03:00
Leonard Crestez
1a0013c62b interconnect: Add interconnect_graph file to debugfs
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>
2019-12-16 09:49:54 +02:00
Louis Taylor
67dd7d87d4 docs: driver-api: make interconnect title quieter
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>
2019-11-07 13:17:24 -07:00
Mauro Carvalho Chehab
9b1f44028f docs: interconnect.rst: add it to the driver-api guide
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