| # SPDX-License-Identifier: GPL-2.0-only |
| config NTB_IDT |
| tristate "IDT PCIe-switch Non-Transparent Bridge support" |
| depends on PCI |
| select HWMON |
| help |
| This driver supports NTB of cappable IDT PCIe-switches. |
| |
| Some of the pre-initializations must be made before IDT PCIe-switch |
| exposes it NT-functions correctly. It should be done by either proper |
| initialisation of EEPROM connected to master smbus of the switch or |
| by BIOS using slave-SMBus interface changing corresponding registers |
| value. Evidently it must be done before PCI bus enumeration is |
| finished in Linux kernel. |
| |
| First of all partitions must be activated and properly assigned to all |
| the ports with NT-functions intended to be activated (see SWPARTxCTL |
| and SWPORTxCTL registers). Then all NT-function BARs must be enabled |
| with chosen valid aperture. For memory windows related BARs the |
| aperture settings shall determine the maximum size of memory windows |
| accepted by a BAR. Note that BAR0 must map PCI configuration space |
| registers. |
| |
| It's worth to note, that since a part of this driver relies on the |
| BAR settings of peer NT-functions, the BAR setups can't be done over |
| kernel PCI fixups. That's why the alternative pre-initialization |
| techniques like BIOS using SMBus interface or EEPROM should be |
| utilized. |
| |
| If unsure, say N. |
| |
