Can we change the register value of DSI interface in TX1 via any utilities, commands or apis in linux user space ?

Hello all,

In order to resolve the black screen issue on our external embedded monitor, we want to reset the DSI interface in TX1 after booting procedures for syncing the timing of power sequence between TX1’s DSI and our external circuit. After researching the documents as Tegra_X1_TRM_DP07225001_v1.0p and NVIDIA_Tegra_Linux_Driver_Package from you, I found one opportunity like as below list at page 2072 in Tegra_X1_TRM_DP07225001_v1.0p. I don’t know whether we can read/write the register in user space. And is there any chances to change this register value by using any utilities, apis or commands in user space besides modifying the DSI driver in kernel space ? Can you kindly help to give us an advice, please ?

"26.5.10 Soft Reset Programming

Soft reset is asserted in the DSI through the LEG_DSI_ENABLE control field of the DSI_DSI_POWER_CONTROL_0 register. When soft reset is asserted, the DSI controller transitions the internal states to default mode. When it is asserted between valid transactions, the current transaction is halted, the internal states are moved to default mode, and a new transaction starts by programming the desired values following the programming sequence explained in the other sections.

Note: For Host transmissions enabled through the DSI_HOST_TRIGGER field of the
DSI_DSI_TRIGGER_0 register, soft reset cannot be issued between a transaction, and
software will write 1’b0 to the register to clear the trigger bit."

Hi jliangu1ak6,

If you know the register address and the value you need to write. You could use devmem2 tool to write the register directly.

It is a 3rdparty tool and you should be able to get the installation method from Internet. Please be careful for the 32/64bit long.