From 486f25c72757dc5453ba4478861128146977561f Mon Sep 17 00:00:00 2001 From: Raviteja Narayanam Date: Thu, 1 Apr 2021 07:14:10 -0600 Subject: [PATCH] arm64: zynqmp: Add 'i2c-mux-idle-disconnect' property I2C muxes that have the slave devices with same address are falling into the below problem. VCK190 system controller (SC) - zynqmp-e-a2197-00-revA.dts I2C1 (0xff030000) -> Mux1 (@0x74) -> Channel 3 -> 0x50 I2C1 (0xff030000) -> Mux2 (@0x75) -> Channel 0 -> 0x50 1. SC accesses I2C1 - Mux1 (0x74) - Channel 3 and then 2. SC accesses I2C1 - Mux2 (0x75) - Channel 0. Now it results in 2 slave devices with same address (0x50) on the I2C bus, making the communication un-reliable. When ' i2c-mux-idle-disconnect' is in DT, after '1', the Mux channel output is disconnected, making none of the channels available to the I2C1. So, there is no question of having the same addressed slave (0x50) present on the bus when we are doing '2'. Same pattern is seen in below two boards also. ZCU208 - zynqmp-zcu208-revA.dts ZCU216 - zynqmp-zcu216-revA.dts Signed-off-by: Raviteja Narayanam --- arch/arm/dts/zynqmp-e-a2197-00-revA.dts | 2 ++ arch/arm/dts/zynqmp-zcu208-revA.dts | 2 ++ arch/arm/dts/zynqmp-zcu216-revA.dts | 2 ++ 3 files changed, 6 insertions(+) diff --git a/arch/arm/dts/zynqmp-e-a2197-00-revA.dts b/arch/arm/dts/zynqmp-e-a2197-00-revA.dts index ffa3dbb5f7..8ec2e86653 100644 --- a/arch/arm/dts/zynqmp-e-a2197-00-revA.dts +++ b/arch/arm/dts/zynqmp-e-a2197-00-revA.dts @@ -457,6 +457,7 @@ #address-cells = <1>; #size-cells = <0>; reg = <0x74>; + i2c-mux-idle-disconnect; /* reset-gpios = <&gpio SYSCTLR_IIC_MUX1_RESET_B GPIO_ACTIVE_HIGH>; */ dc_i2c: i2c@0 { /* DC_I2C */ #address-cells = <1>; @@ -561,6 +562,7 @@ #address-cells = <1>; #size-cells = <0>; reg = <0x75>; + i2c-mux-idle-disconnect; i2c@0 { /* SFP0_IIC */ #address-cells = <1>; #size-cells = <0>; diff --git a/arch/arm/dts/zynqmp-zcu208-revA.dts b/arch/arm/dts/zynqmp-zcu208-revA.dts index 0e114cdacb..c24301090d 100644 --- a/arch/arm/dts/zynqmp-zcu208-revA.dts +++ b/arch/arm/dts/zynqmp-zcu208-revA.dts @@ -388,6 +388,7 @@ #address-cells = <1>; #size-cells = <0>; reg = <0x74>; + i2c-mux-idle-disconnect; /* FIXME reset-gpios = <&tca6416_u15 SYSCTLR_IIC_MUX0_RESET_B GPIO_ACTIVE_HIGH>; */ i2c_eeprom: i2c@0 { #address-cells = <1>; @@ -504,6 +505,7 @@ #address-cells = <1>; #size-cells = <0>; reg = <0x75>; + i2c-mux-idle-disconnect; /* FIXME reset-gpios = <&tca6416_u15 SYSCTLR_IIC_MUX0_RESET_B GPIO_ACTIVE_HIGH>; */ i2c@0 { #address-cells = <1>; diff --git a/arch/arm/dts/zynqmp-zcu216-revA.dts b/arch/arm/dts/zynqmp-zcu216-revA.dts index 2302b07c48..675baf4bed 100644 --- a/arch/arm/dts/zynqmp-zcu216-revA.dts +++ b/arch/arm/dts/zynqmp-zcu216-revA.dts @@ -399,6 +399,7 @@ #address-cells = <1>; #size-cells = <0>; reg = <0x74>; + i2c-mux-idle-disconnect; /* FIXME reset-gpios = <&tca6416_u15 SYSCTLR_IIC_MUX0_RESET_B GPIO_ACTIVE_HIGH>; */ i2c_eeprom: i2c@0 { #address-cells = <1>; @@ -515,6 +516,7 @@ #address-cells = <1>; #size-cells = <0>; reg = <0x75>; + i2c-mux-idle-disconnect; /* FIXME reset-gpios = <&tca6416_u15 SYSCTLR_IIC_MUX0_RESET_B GPIO_ACTIVE_HIGH>; */ i2c@0 { #address-cells = <1>; -- 2.39.5