CTRLMMR_MCU_SPI1_CTRL register controls if MCU_SPI1 is directly connected to SPI3 in the MAIN Domain (default) or if MCU_SPI1 and SPI3 are independently pinned out. By default, the field SPI1_LINKDIS (Bit 0) is set to 0h. In order to disable the direct connection, the SPI1_LINKDIS (Bit 0) needs to be set to 1h. Model this functionality as a "reg-mux" device and based on the idle-state property, enable/disable the connection bewtween MCU_SPI1 and MAIN_SPI3. The register field description has been referred from J7200 TRM [1] (Table 5-517. CTRLMMR_MCU_SPI1_CTRL Register Field Descriptions). [1] https://www.ti.com/lit/pdf/spruiu1 Signed-off-by: Anurag Dutta <a-dutta@xxxxxx> --- Hi all, The above functionality can be achieved by changing the idle-state of the "spi1_linkdis" node. As observed, when the SPI1_LINKDIS (Bit 0) is 0h, the connection remains enabled and SPIDEV loopback test is succssful [1]. But, when the state changes to 1, the the SPI1_LINKDIS (Bit 0) becomes 1h and the SPIDEV loopback test fails [2] indicating that the connection between MCU_SPI1 and MAIN_SPI3 has been disabled. Test logs: [1] https://gist.github.com/anuragdutta731/9ac287f27f1dfb3a5ccee4cc86e02dbb [2] https://gist.github.com/anuragdutta731/3ed7b7b5a1a3dab494ba46858b972088 arch/arm64/boot/dts/ti/k3-j7200-common-proc-board.dts | 4 ++++ arch/arm64/boot/dts/ti/k3-j7200-mcu-wakeup.dtsi | 7 +++++++ 2 files changed, 11 insertions(+) diff --git a/arch/arm64/boot/dts/ti/k3-j7200-common-proc-board.dts b/arch/arm64/boot/dts/ti/k3-j7200-common-proc-board.dts index db43e7e10b76..f684ce6ad9ad 100644 --- a/arch/arm64/boot/dts/ti/k3-j7200-common-proc-board.dts +++ b/arch/arm64/boot/dts/ti/k3-j7200-common-proc-board.dts @@ -409,6 +409,10 @@ &serdes_ln_ctrl { <J7200_SERDES0_LANE2_QSGMII_LANE1>, <J7200_SERDES0_LANE3_IP4_UNUSED>; }; +&mcu_spi1 { + mux-controls = <&spi1_linkdis 0>; +}; + &usb_serdes_mux { idle-states = <1>; /* USB0 to SERDES lane 3 */ bootph-all; diff --git a/arch/arm64/boot/dts/ti/k3-j7200-mcu-wakeup.dtsi b/arch/arm64/boot/dts/ti/k3-j7200-mcu-wakeup.dtsi index 6a8453865874..56ab144fea07 100644 --- a/arch/arm64/boot/dts/ti/k3-j7200-mcu-wakeup.dtsi +++ b/arch/arm64/boot/dts/ti/k3-j7200-mcu-wakeup.dtsi @@ -184,6 +184,13 @@ phy_gmii_sel: phy@4040 { reg = <0x4040 0x4>; #phy-cells = <1>; }; + + spi1_linkdis: mux-controller@4060 { + compatible = "reg-mux"; + reg = <0x4060 0x4>; + #mux-control-cells = <1>; + mux-reg-masks = <0x0 0x1>; + }; }; wkup_conf: bus@43000000 { -- 2.34.1
