bsc9132 I2C channel 2. No devices are found and the channel is enabled in SW12

[edliversidge]

Hi,

there should be three PCA9546 devices on I2C channel #2 for the BSC9132QDS board, however u-boot cannot find them.

  => i2c probe

  Valid chip addresses: 21 50 53 54 55 56 57 66 68

  => i2c dev

  Current bus is 0

  => i2c dev 1

  Setting bus to 1

  => i2c probe

  Valid chip addresses:

The channel is enabled in SW12.

Can anyone help me find the devices?

[edliversidge]

Of course it is more complicated than that.....

There seems to be a register in the QIXIS FPGA which also controls pin multiplexing for I2C2:

USB/I2C2/UART2 BRDCFG5[0:1] FPGA_USB_MUX[0:1

00 Disconnection

01 DUT_ULPI USB PHY

10 GPIO to/from FPGA

11 UART2,I2C UART PHY, I2C switch

Can someone explain how to get the second I2C channel working? Do I need to program this FPGA?

[lunminliang · Accepted solution]

Hi,

BSC9132 I2C2 controller is not enabled by default in WUSDK BSP.

Yes, you are right to configure GUTS_PMUXCR3 and BRDCFG5 for this purpose, see below steps for how to do:

=> mm ff7e0068

ff7e0068: 00000000 ? 00000600

=> i2c mw 66 55 e0

=> i2c dev 1

Setting bus to 1

=> i2c probe

Valid chip addresses: 70 71 72

Have a great day,
Lunmin

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[manjanagoudapat]

hello lunminliang ,

how can i make this as default in u-boot? because i am not using usb . it is making me run

=> mm ff7e0068

ff7e0068: 00000000 ? 00000600

these commands each time i boot the board

thanks and regards

patil m

[edliversidge]

I think I have it.

The  IIC2_SDA and IIC2_SCL pins are not configured to be used by the chip by default. The GUTS_PMUXCR3 register must be correctly configured.

I would have been good to see this in the QDS board reference manual somewhere.