imx8mp csis-hs-settle and csis-clk-settle calculations

[Navee_nK]

Hi, 
I want to know the respective values to set in csis-hs-settle and csis-clk-settle.

The Data rates am working with are 891 Mbps, 1782 Mbps and 2079 Mbps. For these what value should I keep in my device tree? Kindly help me with this. 

Thanks. 

[Chavira]

HI @Navee_nK!

Based on the i.MX 8M Plus Reference Manual, the values for csis-hs-settle and csis-clk-settle in the device tree are determined by the MIPI D-PHY timing requirements, which are directly influenced by the CSI interface data rate.

These parameters are configured through the following registers:

HSSETTLE[7:0] → corresponds to csis-hs-settle
CLKSETTLECTL[1:0] → corresponds to csis-clk-settle

To ensure proper bandwidth matching between the CSI receiver and the image sensor, the following equation must be satisfied:

RX_BYTE_CLK_HS×Number of Data Lanes×8≤Pixel Clock×Bitwidth of Image Format×Pixels per Clock

This formula and its context are documented in the MIPI CSI Host Controller section of the Reference Manual, specifically on page 5364.

Best Regards,

Chavira