On 26.03.20 03:16, Leonard Crestez wrote: > This series adds interconnect scaling support for imx8m series chips. It uses a > per-SOC interconnect provider layered on top of multiple instances of devfreq > for scalable nodes along the interconnect. > > Existing qcom interconnect providers mostly translate bandwidth requests into > firmware calls but equivalent firmware on imx8m is much thinner. Scaling > support for individual nodes is implemented as distinct devfreq drivers > instead. > > The imx interconnect provider doesn't communicate with devfreq directly > but rather computes "minimum frequencies" for nodes along the path and > creates dev_pm_qos requests. > > Since there is no single devicetree node that can represent the > "interconnect" the main NOC is picked as the "interconnect provider" and > will probe the interconnect platform device if #interconnect-cells is > present. This avoids introducing "virtual" devices but it means that DT > bindings of main NOC includes properties for both devfreq and > interconnect. > > Only the ddrc and main noc are scalable right now but more can be added. > > Also available on a github branch (with various unrelated changes): > https://github.com/cdleonard/linux/tree/next > Testing currently requires NXP branch of atf+uboot > > Martin: I believe you should be able to use this to control DRAM > frequency from video by just adding interconnect consumer code to > nwl-dsi. Sample code: > https://github.com/cdleonard/linux/commit/43772762aa5045f1ce5623740f9a4baef988d083 > https://github.com/cdleonard/linux/commit/7b601e981b1f517b5d98b43bde292972ded13086 > Thanks for updating this series Leonard! A few questions for my understanding before trying to test: Isn't the ddrc_opp_table missing in these additions to the DT? That's what I want to scale after all. If I want to keep calling the "request", now icc_set_bw(), in nwl-dsi: I'd add an "interconnects" property to the node, but what would be my interconnect master? i.e.: interconnects = <&noc master? &noc IMX8MQ_ICS_DRAM>; At least it's not obvious to me from interconnect/imx/imx8mq.c the interconnect framework seems to be powerful indeed, but I still need to fully wrap my head around it. thanks for the help so far, martin > Changes since RFCv6: > * Replace scalable-nodes stuff with just a fsl,ddrc property. Future > scalable nodes can be added as additional phandles on the NOC > * Allow building interconnect drivers as modules > * Handle icc_provider_del errors in imx_icc_unregister (like EBUSY). > * Rename imx-devfreq to imx-bus, similar to exynos-bus > * Explain why imx bus clock enabling is not required > * All dependencies accepted (some time ago). > Link: https://patchwork.kernel.org/cover/11244421/ > > Changes since RFCv5: > * Replace scanning for interconnect-node-id with explicit > scalable-nodes/scalable-node-ids property on NoC. > * Now passes make `dtbs_check` > * Remove struct imx_icc_provider > * Switch to of_icc_xlate_onecell > * Use of_find_device_by_node to fetch QoS target, this causes fewer probe > deferrals, removes dependency on devfreq API and even allows reloading ddrc > module at runtime > * Add imx_icc_node_destroy helper > * Remove 0/1 on DEFINE_BUS_SLAVE/MASTER which created spurious links > Link: https://patchwork.kernel.org/cover/11222015/ > > Changes since RFCv4: > * Drop icc proxy nonsense > * Make devfreq driver for NOC probe the ICC driver if > #interconnect-cells is present > * Move NOC support to interconnect series and rename the node in DT > * Add support for all chips at once, differences are not intereseting > and there is more community interest for 8mq than 8mm. > Link: https://patchwork.kernel.org/cover/11111865/ > > Changes since RFCv3: > * Remove the virtual "icc" node and add devfreq nodes as proxy providers > * Fix build on 32-bit arm (reported by kbuilt test robot) > * Remove ARCH_MXC_ARM64 (never existed in upstream) > * Remove _numlinks, calculate instead > * Replace __BUSFREQ_H header guard > * Improve commit message and comment spelling > * Fix checkpatch issues > Link to RFCv3: https://patchwork.kernel.org/cover/11078671/ > > Changes since RFCv2 and initial work by Alexandre Bailon: > * Relying on devfreq and dev_pm_qos instead of CLK > * No more "platform opp" stuff > * No more special suspend handling: use suspend-opp on devfreq instead > * Replace all mentions of "busfreq" with "interconnect" > Link to v2: https://patchwork.kernel.org/cover/11021563/ > > Leonard Crestez (8): > dt-bindings: interconnect: Add bindings for imx8m noc > PM / devfreq: Add generic imx bus scaling driver > PM / devfreq: imx: Register interconnect device > interconnect: Add imx core driver > interconnect: imx: Add platform driver for imx8mm > interconnect: imx: Add platform driver for imx8mq > interconnect: imx: Add platform driver for imx8mn > arm64: dts: imx8m: Add NOC nodes > > .../bindings/interconnect/fsl,imx8m-noc.yaml | 138 ++++++++ > arch/arm64/boot/dts/freescale/imx8mm.dtsi | 24 ++ > arch/arm64/boot/dts/freescale/imx8mn.dtsi | 24 ++ > arch/arm64/boot/dts/freescale/imx8mq.dtsi | 24 ++ > drivers/devfreq/Kconfig | 9 + > drivers/devfreq/Makefile | 1 + > drivers/devfreq/imx-bus.c | 181 +++++++++++ > drivers/interconnect/Kconfig | 1 + > drivers/interconnect/Makefile | 1 + > drivers/interconnect/imx/Kconfig | 17 + > drivers/interconnect/imx/Makefile | 9 + > drivers/interconnect/imx/imx.c | 298 ++++++++++++++++++ > drivers/interconnect/imx/imx.h | 62 ++++ > drivers/interconnect/imx/imx8mm.c | 108 +++++++ > drivers/interconnect/imx/imx8mn.c | 97 ++++++ > drivers/interconnect/imx/imx8mq.c | 106 +++++++ > include/dt-bindings/interconnect/imx8mm.h | 49 +++ > include/dt-bindings/interconnect/imx8mn.h | 41 +++ > include/dt-bindings/interconnect/imx8mq.h | 48 +++ > 19 files changed, 1238 insertions(+) > create mode 100644 Documentation/devicetree/bindings/interconnect/fsl,imx8m-noc.yaml > create mode 100644 drivers/devfreq/imx-bus.c > create mode 100644 drivers/interconnect/imx/Kconfig > create mode 100644 drivers/interconnect/imx/Makefile > create mode 100644 drivers/interconnect/imx/imx.c > create mode 100644 drivers/interconnect/imx/imx.h > create mode 100644 drivers/interconnect/imx/imx8mm.c > create mode 100644 drivers/interconnect/imx/imx8mn.c > create mode 100644 drivers/interconnect/imx/imx8mq.c > create mode 100644 include/dt-bindings/interconnect/imx8mm.h > create mode 100644 include/dt-bindings/interconnect/imx8mn.h > create mode 100644 include/dt-bindings/interconnect/imx8mq.h >
