| Tom Rini | 93743d2 | 2024-04-01 09:08:13 -0400 | [diff] [blame] | 1 | // SPDX-License-Identifier: (GPL-2.0+ OR MIT) |
| 2 | /* |
| 3 | * Copyright (C) 2023 Marvell International Ltd. |
| 4 | * |
| 5 | * Device tree for the AC5X RD Type 7 Com Express carrier board, |
| 6 | * This specific board in external mode (see below) only maintains |
| 7 | * a PCIe link with the COM Express CPU module, which does not |
| 8 | * require any special DTS definitions. |
| 9 | * |
| 10 | * AC5X RD can either work as you would expect, as a complete standalone |
| 11 | * box using the internal CPU, or you can move the switch on the back of |
| 12 | * the box to "external" mode, and connect via an external cable a kit |
| 13 | * which would allow it to use an external CPU COM Express module, |
| 14 | * mounted on top of an interposer kit. |
| 15 | * |
| 16 | * So in this case, once the switch is set to external mode as explained above, |
| 17 | * the AC5X RD becomes part of the carrier solution. |
| 18 | * This is a development/reference solution, not a full commercial solution, |
| 19 | * hence it was designed with the flexibility to be configured in different |
| 20 | * modes of operation. |
| 21 | * |
| 22 | * When the board boots in the external CPU mode, the internal CPU is disabled, |
| 23 | * and only the switch portion of the SOC acts as a PCIe end-point, Hence there |
| 24 | * is no need to describe this internal (disabled CPU) in the device tree. |
| 25 | * |
| 26 | * There is no CPU booting in this mode on the carrier, |
| 27 | * only on the COM Express CPU module. |
| 28 | */ |
| 29 | |
| 30 | / { |
| 31 | model = "Marvell Armada AC5X RD COM EXPRESS type 7 carrier board"; |
| 32 | compatible = "marvell,rd-ac5x-carrier"; |
| 33 | |
| 34 | }; |