How to handle named resources with DT?

Paul Walmsley paul at pwsan.com
Sun Aug 28 05:31:05 EST 2011


On Sat, 27 Aug 2011, Arnd Bergmann wrote:

> Right, and I guess we can simply ignore DMA and ioport resources because 
> they are extremely rare, right?

DMA resources are quite widely used.

For example, looking at the SoCs with some publicly-available 
documentation, the Motorola i.MX51 reference manual lists 47 SDMA request 
lines across about 17 different IP block types[1], and to pick a 
representative OMAP, the OMAP3430 technical reference manual lists 77 SDMA 
request lines, used by at least 9 different IP block types[2].

Also, many IP blocks have multiple DMA resources.  For example, the above 
references list UART, MCSPI, PATA, I2C, FIRI, MCBSP, SSI, CTI, CSPI, 
eCSPI, EMI, eSDHC, SPI, and DSS.


- Paul

1. Table 3-3, "SDMA Event Mapping".  _MCIMX51 Multimedia Applications 
   Processor Reference Manual (MCIMX51RM) Rev. 1 2/2010_.  Available from
   http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=i.MX515&fpsp=1&tab=Documentation_Tab

2. This is simply one example from the OMAP3430 TRM, but similar tables
   are available for OMAP2420, 2430, 3430, 3630, 4430, 4460, 4470, etc.
   Table 9-3, "SDMA Request Mapping". _OMAP34xx Multimedia Device Silicon 
   Revision 3.1.x Version J (SWPU223J)_ (public version).  Available from 
   http://focus.ti.com/general/docs/wtbu/wtbudocumentcenter.tsp?templateId=6123&navigationId=12667



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