Hello All,
We’ve developed a board based on the BeagleBone Black. We’ve created an external peripheral bus using GPIO lines, controlled by the GPMC, to access multiple Quad UARTs and latches located on an extension board. The chip selects (1-3) and address ranges are shown in the chart below.
CHIP SELECT / ADDRESS CHART:
CSx BASE ADDR SIZE DEVICES
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CS1 0x01000000 0x01000000 (16 MB) (2 UARTS)
CS2 0x02000000 0x01000000 (16 MB) (Not Used)
CS3 0x03000000 0x01000000 (16 MB) (0-20 UARTs, Latches, etc.)
I need to modify the .dts files to include the external UARTs and latches. But I’m not sure where the nodes should go, or what the exact syntax should be. (Ex: Should there be a parent node defining the external bus? Which .dts file?) I’ve done this before with a PowerPC implementation (See “localbus@” and “serial@” in included file: “wti870.dts”). Can you tell me how to port these nodes, and/or show some examples?
We also need to assign GPIO3_16 as IRQ6, which we are using as an interrupt signal for these external UARTs. Not quite sure how to make this assignment in the dts. Any help would be greatly appreciated! Thanks in advance! - Anthony