linux/Documentation/arm/IXP4xx
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   2-------------------------------------------------------------------------
   3Release Notes for Linux on Intel's IXP4xx Network Processor
   4
   5Maintained by Deepak Saxena <dsaxena@plexity.net>
   6-------------------------------------------------------------------------
   7
   81. Overview
   9
  10Intel's IXP4xx network processor is a highly integrated SOC that
  11is targeted for network applications, though it has become popular 
  12in industrial control and other areas due to low cost and power
  13consumption. The IXP4xx family currently consists of several processors
  14that support different network offload functions such as encryption,
  15routing, firewalling, etc. The IXP46x family is an updated version which
  16supports faster speeds, new memory and flash configurations, and more
  17integration such as an on-chip I2C controller.
  18
  19For more information on the various versions of the CPU, see:
  20
  21   http://developer.intel.com/design/network/products/npfamily/ixp4xx.htm
  22
  23Intel also made the IXCP1100 CPU for sometime which is an IXP4xx 
  24stripped of much of the network intelligence.
  25
  262. Linux Support
  27
  28Linux currently supports the following features on the IXP4xx chips:
  29
  30- Dual serial ports
  31- PCI interface
  32- Flash access (MTD/JFFS)
  33- I2C through GPIO on IXP42x
  34- GPIO for input/output/interrupts 
  35  See arch/arm/mach-ixp4xx/include/mach/platform.h for access functions.
  36- Timers (watchdog, OS)
  37
  38The following components of the chips are not supported by Linux and
  39require the use of Intel's proprietary CSR softare:
  40
  41- USB device interface
  42- Network interfaces (HSS, Utopia, NPEs, etc)
  43- Network offload functionality
  44
  45If you need to use any of the above, you need to download Intel's
  46software from:
  47
  48   http://developer.intel.com/design/network/products/npfamily/ixp425.htm    
  49
  50DO NOT POST QUESTIONS TO THE LINUX MAILING LISTS REGARDING THE PROPRIETARY
  51SOFTWARE.
  52
  53There are several websites that provide directions/pointers on using
  54Intel's software:
  55
  56   http://sourceforge.net/projects/ixp4xx-osdg/
  57   Open Source Developer's Guide for using uClinux and the Intel libraries 
  58
  59http://gatewaymaker.sourceforge.net/ 
  60   Simple one page summary of building a gateway using an IXP425 and Linux
  61
  62http://ixp425.sourceforge.net/
  63   ATM device driver for IXP425 that relies on Intel's libraries
  64
  653. Known Issues/Limitations
  66
  673a. Limited inbound PCI window
  68
  69The IXP4xx family allows for up to 256MB of memory but the PCI interface
  70can only expose 64MB of that memory to the PCI bus. This means that if
  71you are running with > 64MB, all PCI buffers outside of the accessible
  72range will be bounced using the routines in arch/arm/common/dmabounce.c.
  73   
  743b. Limited outbound PCI window
  75
  76IXP4xx provides two methods of accessing PCI memory space:
  77
  781) A direct mapped window from 0x48000000 to 0x4bffffff (64MB).
  79   To access PCI via this space, we simply ioremap() the BAR
  80   into the kernel and we can use the standard read[bwl]/write[bwl]
  81   macros. This is the preffered method due to speed but it
  82   limits the system to just 64MB of PCI memory. This can be 
  83   problamatic if using video cards and other memory-heavy devices.
  84          
  852) If > 64MB of memory space is required, the IXP4xx can be 
  86   configured to use indirect registers to access PCI This allows 
  87   for up to 128MB (0x48000000 to 0x4fffffff) of memory on the bus. 
  88   The disadvantage of this is that every PCI access requires 
  89   three local register accesses plus a spinlock, but in some 
  90   cases the performance hit is acceptable. In addition, you cannot 
  91   mmap() PCI devices in this case due to the indirect nature
  92   of the PCI window.
  93
  94By default, the direct method is used for performance reasons. If
  95you need more PCI memory, enable the IXP4XX_INDIRECT_PCI config option.
  96
  973c. GPIO as Interrupts
  98
  99Currently the code only handles level-sensitive GPIO interrupts 
 100
 1014. Supported platforms
 102
 103ADI Engineering Coyote Gateway Reference Platform
 104http://www.adiengineering.com/productsCoyote.html
 105
 106   The ADI Coyote platform is reference design for those building 
 107   small residential/office gateways. One NPE is connected to a 10/100
 108   interface, one to 4-port 10/100 switch, and the third to and ADSL
 109   interface. In addition, it also supports to POTs interfaces connected
 110   via SLICs. Note that those are not supported by Linux ATM. Finally,
 111   the platform has two mini-PCI slots used for 802.11[bga] cards.
 112   Finally, there is an IDE port hanging off the expansion bus.
 113
 114Gateworks Avila Network Platform
 115http://www.gateworks.com/support/overview.php
 116
 117   The Avila platform is basically and IXDP425 with the 4 PCI slots
 118   replaced with mini-PCI slots and a CF IDE interface hanging off
 119   the expansion bus.
 120
 121Intel IXDP425 Development Platform
 122http://www.intel.com/design/network/products/npfamily/ixdpg425.htm  
 123
 124   This is Intel's standard reference platform for the IXDP425 and is 
 125   also known as the Richfield board. It contains 4 PCI slots, 16MB
 126   of flash, two 10/100 ports and one ADSL port.
 127
 128Intel IXDP465 Development Platform
 129http://www.intel.com/design/network/products/npfamily/ixdp465.htm
 130
 131   This is basically an IXDP425 with an IXP465 and 32M of flash instead
 132   of just 16.
 133
 134Intel IXDPG425 Development Platform
 135
 136   This is basically and ADI Coyote board with a NEC EHCI controller
 137   added. One issue with this board is that the mini-PCI slots only
 138   have the 3.3v line connected, so you can't use a PCI to mini-PCI
 139   adapter with an E100 card. So to NFS root you need to use either
 140   the CSR or a WiFi card and a ramdisk that BOOTPs and then does
 141   a pivot_root to NFS.
 142
 143Motorola PrPMC1100 Processor Mezanine Card
 144http://www.fountainsys.com
 145
 146   The PrPMC1100 is based on the IXCP1100 and is meant to plug into
 147   and IXP2400/2800 system to act as the system controller. It simply
 148   contains a CPU and 16MB of flash on the board and needs to be
 149   plugged into a carrier board to function. Currently Linux only
 150   supports the Motorola PrPMC carrier board for this platform.
 151
 1525. TODO LIST
 153
 154- Add support for Coyote IDE
 155- Add support for edge-based GPIO interrupts
 156- Add support for CF IDE on expansion bus
 157
 1586. Thanks
 159
 160The IXP4xx work has been funded by Intel Corp. and MontaVista Software, Inc.
 161
 162The following people have contributed patches/comments/etc:
 163
 164Lennerty Buytenhek
 165Lutz Jaenicke
 166Justin Mayfield
 167Robert E. Ranslam
 168[I know I've forgotten others, please email me to be added] 
 169
 170-------------------------------------------------------------------------
 171
 172Last Update: 01/04/2005
 173
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