The following patchset adds interconnect[1][2] framework support to the
exynos-bus devfreq driver. Extending the devfreq driver with
interconnect functionality started as a response to the issue referenced
in [3]. The patches can be subdivided into three groups:
(a) Tweaking the interconnect framework to support the exynos-bus use
case (patches 01--03/07). Exporting of_icc_get_from_provider() allows to
avoid hardcoding every single graph edge in the DT or driver source, and
relaxing the requirement on #interconnect-cells removes the need to
provide dummy node IDs in the DT. A new field in struct icc_provider is
used to explicitly allow configuring node pairs from two different
providers.
(b) Implementing interconnect providers in the exynos-bus devfreq driver
and adding required DT properties for one selected platform, namely
Exynos4412 (patches 04--05/07). Due to the fact that this aims to be a
generic driver for various Exynos SoCs, node IDs are generated
dynamically (rather than hardcoded).
(c) Implementing a sample interconnect consumer for exynos-mixer
targeted at solving the issue referenced in [3], again with DT
properties only for Exynos4412 (patches 06--07/07).
Integration of devfreq and interconnect frameworks is achieved by using
the dev_pm_qos_*() API. When CONFIG_INTERCONNECT is 'n' (such as in
exynos_defconfig) all interconnect API functions are no-ops.
This series depends on these three patches (merged into devfreq-next[6]):
* https://patchwork.kernel.org/patch/11279087/
* https://patchwork.kernel.org/patch/11279093/
* https://patchwork.kernel.org/patch/11293765/
and on this series:
* https://patchwork.kernel.org/cover/11304545/
(which does not apply cleanly on next-20191220, adding
--exclude=arch/arm/boot/dts/exynos5422-odroid-core.dtsi to 'git am' is a
quick workaround)
---
Changes since v2 [5]:
* Use icc_std_aggregate().
* Implement a different modification of apply_constraints() in
drivers/interconnect/core.c (patch 03).
* Use 'exynos,interconnect-parent-node' in the DT instead of
'devfreq'/'parent', depending on the bus.
* Rebase on DT patches that deprecate the 'devfreq' DT property.
* Improve error handling, including freeing generated IDs on failure.
* Remove exynos_bus_icc_connect() and add exynos_bus_icc_get_parent().
---
Changes since v1 [4]:
* Rebase on coupled regulators patches.
* Use dev_pm_qos_*() API instead of overriding frequency in
exynos_bus_target().
* Use IDR for node ID allocation.
* Reverse order of multiplication and division in
mixer_set_memory_bandwidth() (patch 07) to avoid integer overflow.
---
Artur Świgoń
Samsung R&D Institute Poland
Samsung Electronics
---
References:
[1] Documentation/interconnect/interconnect.rst
[2] Documentation/devicetree/bindings/interconnect/interconnect.txt
[3] https://patchwork.kernel.org/patch/10861757/ (original issue)
[4] https://patchwork.kernel.org/cover/11054417/ (v1 of this RFC)
[5] https://patchwork.kernel.org/cover/11152595/ (v2 of this RFC)
[6] https://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux.git/log/?h=devfreq-next
Artur Świgoń (6):
interconnect: Export of_icc_get_from_provider()
interconnect: Relax requirement in of_icc_get_from_provider()
interconnect: Allow inter-provider pairs to be configured
arm: dts: exynos: Add interconnect bindings for Exynos4412
devfreq: exynos-bus: Add interconnect functionality to exynos-bus
arm: dts: exynos: Add interconnects to Exynos4412 mixer
Marek Szyprowski (1):
drm: exynos: mixer: Add interconnect support
.../boot/dts/exynos4412-odroid-common.dtsi | 5 +
arch/arm/boot/dts/exynos4412.dtsi | 1 +
drivers/devfreq/exynos-bus.c | 144 ++++++++++++++++++
drivers/gpu/drm/exynos/exynos_mixer.c | 71 ++++++++-
drivers/interconnect/core.c | 16 +-
include/linux/interconnect-provider.h | 8 +
6 files changed, 232 insertions(+), 13 deletions(-)
--
2.17.1
This patch relaxes the condition in of_icc_get_from_provider() so that it
is no longer required to set #interconnect-cells = <1> in the DT. In case
of the devfreq driver for exynos-bus, #interconnect-cells is always zero.
Signed-off-by: Artur Świgoń <[email protected]>
Acked-by: Krzysztof Kozlowski <[email protected]>
---
drivers/interconnect/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
index e6035c199369..74c68898a350 100644
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -335,7 +335,7 @@ struct icc_node *of_icc_get_from_provider(struct of_phandle_args *spec)
struct icc_node *node = ERR_PTR(-EPROBE_DEFER);
struct icc_provider *provider;
- if (!spec || spec->args_count != 1)
+ if (!spec)
return ERR_PTR(-EINVAL);
mutex_lock(&icc_lock);
--
2.17.1
Hi,
On Fri, Dec 20, 2019 at 9:03 PM Artur Świgoń <[email protected]> wrote:
>
> This patch relaxes the condition in of_icc_get_from_provider() so that it
> is no longer required to set #interconnect-cells = <1> in the DT. In case
> of the devfreq driver for exynos-bus, #interconnect-cells is always zero.
It doesn't contain why don't need to require it. If you add more detailed
description, it is better to understand.
>
> Signed-off-by: Artur Świgoń <[email protected]>
> Acked-by: Krzysztof Kozlowski <[email protected]>
> ---
> drivers/interconnect/core.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
> index e6035c199369..74c68898a350 100644
> --- a/drivers/interconnect/core.c
> +++ b/drivers/interconnect/core.c
> @@ -335,7 +335,7 @@ struct icc_node *of_icc_get_from_provider(struct of_phandle_args *spec)
> struct icc_node *node = ERR_PTR(-EPROBE_DEFER);
> struct icc_provider *provider;
>
> - if (!spec || spec->args_count != 1)
> + if (!spec)
> return ERR_PTR(-EINVAL);
>
> mutex_lock(&icc_lock);
> --
> 2.17.1
>
--
Best Regards,
Chanwoo Choi
Hi Artur,
I agree this approach. On next version, please update exynos-bus
dt-binding document with example.
On Fri, Dec 20, 2019 at 9:01 PM Artur Świgoń <[email protected]> wrote:
>
> The following patchset adds interconnect[1][2] framework support to the
> exynos-bus devfreq driver. Extending the devfreq driver with
> interconnect functionality started as a response to the issue referenced
> in [3]. The patches can be subdivided into three groups:
>
> (a) Tweaking the interconnect framework to support the exynos-bus use
> case (patches 01--03/07). Exporting of_icc_get_from_provider() allows to
> avoid hardcoding every single graph edge in the DT or driver source, and
> relaxing the requirement on #interconnect-cells removes the need to
> provide dummy node IDs in the DT. A new field in struct icc_provider is
> used to explicitly allow configuring node pairs from two different
> providers.
>
> (b) Implementing interconnect providers in the exynos-bus devfreq driver
> and adding required DT properties for one selected platform, namely
> Exynos4412 (patches 04--05/07). Due to the fact that this aims to be a
> generic driver for various Exynos SoCs, node IDs are generated
> dynamically (rather than hardcoded).
>
> (c) Implementing a sample interconnect consumer for exynos-mixer
> targeted at solving the issue referenced in [3], again with DT
> properties only for Exynos4412 (patches 06--07/07).
>
> Integration of devfreq and interconnect frameworks is achieved by using
> the dev_pm_qos_*() API. When CONFIG_INTERCONNECT is 'n' (such as in
> exynos_defconfig) all interconnect API functions are no-ops.
>
> This series depends on these three patches (merged into devfreq-next[6]):
> * https://patchwork.kernel.org/patch/11279087/
> * https://patchwork.kernel.org/patch/11279093/
> * https://patchwork.kernel.org/patch/11293765/
> and on this series:
> * https://patchwork.kernel.org/cover/11304545/
> (which does not apply cleanly on next-20191220, adding
> --exclude=arch/arm/boot/dts/exynos5422-odroid-core.dtsi to 'git am' is a
> quick workaround)
>
> ---
> Changes since v2 [5]:
> * Use icc_std_aggregate().
> * Implement a different modification of apply_constraints() in
> drivers/interconnect/core.c (patch 03).
> * Use 'exynos,interconnect-parent-node' in the DT instead of
> 'devfreq'/'parent', depending on the bus.
> * Rebase on DT patches that deprecate the 'devfreq' DT property.
> * Improve error handling, including freeing generated IDs on failure.
> * Remove exynos_bus_icc_connect() and add exynos_bus_icc_get_parent().
>
> ---
> Changes since v1 [4]:
> * Rebase on coupled regulators patches.
> * Use dev_pm_qos_*() API instead of overriding frequency in
> exynos_bus_target().
> * Use IDR for node ID allocation.
> * Reverse order of multiplication and division in
> mixer_set_memory_bandwidth() (patch 07) to avoid integer overflow.
>
> ---
> Artur Świgoń
> Samsung R&D Institute Poland
> Samsung Electronics
>
> ---
> References:
> [1] Documentation/interconnect/interconnect.rst
> [2] Documentation/devicetree/bindings/interconnect/interconnect.txt
> [3] https://patchwork.kernel.org/patch/10861757/ (original issue)
> [4] https://patchwork.kernel.org/cover/11054417/ (v1 of this RFC)
> [5] https://patchwork.kernel.org/cover/11152595/ (v2 of this RFC)
> [6] https://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux.git/log/?h=devfreq-next
>
> Artur Świgoń (6):
> interconnect: Export of_icc_get_from_provider()
> interconnect: Relax requirement in of_icc_get_from_provider()
> interconnect: Allow inter-provider pairs to be configured
> arm: dts: exynos: Add interconnect bindings for Exynos4412
> devfreq: exynos-bus: Add interconnect functionality to exynos-bus
> arm: dts: exynos: Add interconnects to Exynos4412 mixer
>
> Marek Szyprowski (1):
> drm: exynos: mixer: Add interconnect support
>
> .../boot/dts/exynos4412-odroid-common.dtsi | 5 +
> arch/arm/boot/dts/exynos4412.dtsi | 1 +
> drivers/devfreq/exynos-bus.c | 144 ++++++++++++++++++
> drivers/gpu/drm/exynos/exynos_mixer.c | 71 ++++++++-
> drivers/interconnect/core.c | 16 +-
> include/linux/interconnect-provider.h | 8 +
> 6 files changed, 232 insertions(+), 13 deletions(-)
>
> --
> 2.17.1
>
--
Best Regards,
Chanwoo Choi