1# SPDX-License-Identifier: GPL-2.0-only 2if ARCH_IXP4XX 3 4menu "Intel IXP4xx Implementation Options" 5 6comment "IXP4xx Platforms" 7 8config MACH_IXP4XX_OF 9 bool 10 prompt "Device Tree IXP4xx boards" 11 default y 12 select ARM_APPENDED_DTB # Old Redboot bootloaders deployed 13 select I2C 14 select I2C_IOP3XX 15 select PCI 16 select USE_OF 17 help 18 Say 'Y' here to support Device Tree-based IXP4xx platforms. 19 20config ARCH_PRPMC1100 21 bool "PrPMC1100" 22 help 23 Say 'Y' here if you want your kernel to support the Motorola 24 PrPCM1100 Processor Mezanine Module. For more information on 25 this platform, see <file:Documentation/arm/ixp4xx.rst>. 26 27comment "IXP4xx Options" 28 29config IXP4XX_PCI_LEGACY 30 bool "IXP4xx legacy PCI driver support" 31 depends on PCI 32 help 33 Selects legacy PCI driver. 34 Not recommended for new development. 35 36config IXP4XX_INDIRECT_PCI 37 bool "Use indirect PCI memory access" 38 depends on IXP4XX_PCI_LEGACY 39 help 40 IXP4xx provides two methods of accessing PCI memory space: 41 42 1) A direct mapped window from 0x48000000 to 0x4BFFFFFF (64MB). 43 To access PCI via this space, we simply ioremap() the BAR 44 into the kernel and we can use the standard read[bwl]/write[bwl] 45 macros. This is the preferred method due to speed but it 46 limits the system to just 64MB of PCI memory. This can be 47 problematic if using video cards and other memory-heavy devices. 48 49 2) If > 64MB of memory space is required, the IXP4xx can be 50 configured to use indirect registers to access the whole PCI 51 memory space. This currently allows for up to 1 GB (0x10000000 52 to 0x4FFFFFFF) of memory on the bus. The disadvantage of this 53 is that every PCI access requires three local register accesses 54 plus a spinlock, but in some cases the performance hit is 55 acceptable. In addition, you cannot mmap() PCI devices in this 56 case due to the indirect nature of the PCI window. 57 58 By default, the direct method is used. Choose this option if you 59 need to use the indirect method instead. If you don't know 60 what you need, leave this option unselected. 61 62endmenu 63 64endif 65