On 14.11.2019 22:10, 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. > > This depends on other series for devfreq pm/qos and ddrc: It took a while but all runtime dependencies are included in next-20191210 and the compile-time dependency on DEV_PM_QOS_MIN_FREQUENCY is also included in v5.5-rc1. This series is a bit old but still applies usefully so I thought I'd ask for additional comments instead of a blank resend. Georgi: can you please take a look at this series and suggest what would make it suitable for inclusion? Some dubious aspects: * Existing drivers have multiple providers per SOC (for each internal NOC?) but this is a single driver for the entire SOC topology. Not clear what would be gain from this. * NOC DT node implements devfreq (because it can be scaled) and interconnect (to avoid virtual DT nodes). Maybe the devfreq NOC scaling implementation could be moved into drivers/interconnect/imx? It is quite different from qcom providers but hardware/firmware is also very different. > 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://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpatchwork.kernel.org%2Fcover%2F11222015%2F&data=02%7C01%7Cleonard.crestez%40nxp.com%7Cff0127cbde3e4e6f6c8508d7693eb8d5%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637093590418229667&sdata=0EN1w8RtXHgyvXpRnOovEkWILoVlQ%2FEXJ0zdOOHI%2FgM%3D&reserved=0 > > 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://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpatchwork.kernel.org%2Fcover%2F11111865%2F&data=02%7C01%7Cleonard.crestez%40nxp.com%7Cff0127cbde3e4e6f6c8508d7693eb8d5%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637093590418229667&sdata=bsJqXPVJSszKJf%2BXdqFT2E8wriuKQU00sWwkRqZYmn0%3D&reserved=0 > > 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://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpatchwork.kernel.org%2Fcover%2F11078671%2F&data=02%7C01%7Cleonard.crestez%40nxp.com%7Cff0127cbde3e4e6f6c8508d7693eb8d5%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637093590418229667&sdata=c9xKEw9Fjlv%2FqDiWKr7zOUY5zZMWXjNyApBd94Nidnc%3D&reserved=0 > > 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://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpatchwork.kernel.org%2Fcover%2F11021563%2F&data=02%7C01%7Cleonard.crestez%40nxp.com%7Cff0127cbde3e4e6f6c8508d7693eb8d5%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637093590418229667&sdata=1tEQS9BaHRTjdUYvZJ9%2FJG2BQQGl6hkbPWxiIZ811FY%3D&reserved=0 > > Leonard Crestez (9): > 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 > arm64: dts: imx8m: Add interconnect provider properties > > .../bindings/interconnect/fsl,imx8m-noc.yaml | 104 ++++++ > arch/arm64/boot/dts/freescale/imx8mm.dtsi | 28 ++ > arch/arm64/boot/dts/freescale/imx8mn.dtsi | 28 ++ > arch/arm64/boot/dts/freescale/imx8mq.dtsi | 28 ++ > drivers/devfreq/Kconfig | 9 + > drivers/devfreq/Makefile | 1 + > drivers/devfreq/imx-devfreq.c | 187 +++++++++++ > drivers/interconnect/Kconfig | 1 + > drivers/interconnect/Makefile | 1 + > drivers/interconnect/imx/Kconfig | 17 + > drivers/interconnect/imx/Makefile | 4 + > drivers/interconnect/imx/imx.c | 301 ++++++++++++++++++ > drivers/interconnect/imx/imx.h | 60 ++++ > drivers/interconnect/imx/imx8mm.c | 105 ++++++ > drivers/interconnect/imx/imx8mn.c | 94 ++++++ > drivers/interconnect/imx/imx8mq.c | 103 ++++++ > include/dt-bindings/interconnect/imx8mm.h | 49 +++ > include/dt-bindings/interconnect/imx8mn.h | 41 +++ > include/dt-bindings/interconnect/imx8mq.h | 48 +++ > 19 files changed, 1209 insertions(+) > create mode 100644 Documentation/devicetree/bindings/interconnect/fsl,imx8m-noc.yaml > create mode 100644 drivers/devfreq/imx-devfreq.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 >
