interconnect: add clk-based icc provider support

For some devices it is useful to export clocks as interconnect providers,
if the clock corresponds to bus bandwidth.

For example, on MSM8996 the cluster interconnect clock should be scaled
according to the cluster frequencies. Exporting it as an interconnect
allows one to properly describe this as the cluster bandwidth
requirements.

Tested-by: Yassine Oudjana <y.oudjana@protonmail.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20230512001334.2983048-3-dmitry.baryshkov@linaro.org
Signed-off-by: Georgi Djakov <djakov@kernel.org>

interconnect: Add generic interconnect driver for Exynos SoCs

This patch adds a generic interconnect driver for Exynos SoCs in order
to provide interconnect functionality for each "samsung,exynos-bus"
compatible device.

The SoC topology is a graph (or more specifically, a tree) and its
edges are described by specifying in the 'interconnects' property
the interconnect consumer path for each interconnect provider DT node.

Each bus is now an interconnect provider and an interconnect node as
well (cf. Documentation/interconnect/interconnect.rst), i.e. every bus
registers itself as a node. Node IDs are not hard coded but rather
assigned dynamically at runtime. This approach allows for using this
driver with various Exynos SoCs.

Frequencies requested via the interconnect API for a given node are
propagated to devfreq using dev_pm_qos_update_request(). Please note
that it is not an error when CONFIG_INTERCONNECT is 'n', in which
case all interconnect API functions are no-op.

The samsung,data-clk-ratio DT property is used to specify the ratio
of the interconect bandwidth to the minimum data clock frequency
for each bus.

Due to unspecified relative probing order, -EPROBE_DEFER may be
propagated to ensure that the parent is probed before its children.

Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Tested-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Artur Świgoń <a.swigon@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Link: https://lore.kernel.org/r/20201112140931.31139-3-s.nawrocki@samsung.com
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>

interconnect: Disallow interconnect core to be built as a module

Building individual drivers as modules is fine but allowing a core
framework to be built as a module makes it really complex and should be
avoided.

Whatever uses the interconnect core APIs must also be built as a module
if interconnect core is built as module, else we will see compilation
failures.

If another core framework (like cpufreq, clk, etc), that can't be built
as module, needs to use interconnect APIs then we will start seeing
compilation failures with allmodconfig configurations as the symbols
(like of_icc_get()) used in other frameworks will not be available in
the built-in image.

Disallow the interconnect core to be built as a module to avoid all
these issues.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/b789cce388dd1f2906492f307dea6780c398bc6a.1567065991.git.viresh.kumar@linaro.org
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>

interconnect: Add imx core driver

This adds support for i.MX SoC family to interconnect framework.

Platform drivers can describe the interconnect graph and several
adjustment knobs where icc node bandwidth is converted to a
DEV_PM_QOS_MIN_FREQUENCY request.

The interconnect provider is probed through the main NOC device and
other adjustable nodes on the same graph are found from a
fsl,scalable-nodes phandle array property.

Signed-off-by: Alexandre Bailon <abailon@baylibre.com>
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Tested-by: Martin Kepplinger <martin.kepplinger@puri.sm>
Link: https://lore.kernel.org/r/35920e673df6c04cbbb7d877a7d4ba25fd91a784.1586174566.git.leonard.crestez@nxp.com
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>

treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

interconnect: qcom: Add sdm845 interconnect provider driver

Introduce Qualcomm SDM845 specific provider driver using the
interconnect framework.

Signed-off-by: David Dai <daidavid1@codeaurora.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

interconnect: Add generic on-chip interconnect API

This patch introduces a new API to get requirements and configure the
interconnect buses across the entire chipset to fit with the current
demand.

The API is using a consumer/provider-based model, where the providers are
the interconnect buses and the consumers could be various drivers.
The consumers request interconnect resources (path) between endpoints and
set the desired constraints on this data flow path. The providers receive
requests from consumers and aggregate these requests for all master-slave
pairs on that path. Then the providers configure each node along the path
to support a bandwidth that satisfies all bandwidth requests that cross
through that node. The topology could be complicated and multi-tiered and
is SoC specific.

Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>