Re: wdc PCMCIA force to 16bit capabilities

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Sat, Mar 04, 2017 at 02:22:26PM +0100, smesgr wrote:
> Hi everyone,
> 
> I would like to have an advice on a pcmcia/pc card issue.
> 
> short request:
> 
> According to the Xscale developer documentation the processor is capable of
> accessing PCMCIA in 16-bit.
> 
> "nPCE2 and nPCE1 are byte select high and low for a 16-bit data bus" (6.2.3
> 16-Bit PC Card / Compact Flash Interface @ Intel PXA 255 Processor
> Developer's Manual)
> 
> "[...] that the upper half of the data bus (MD[15:8]) are used for the
> transfer, and nPCE1 to indicate that the lower half of the data bus
> (MD[7:0]) are used. nPCE1 and nPCE2 are asserted for 16-bit accesses."
> (6.8.3 @same document)
> 
> The wdc_pcmcia.c driver always set the capability to 32bit if
> PCMCIA_IFTYPE_MEMORY is not set.
> 
> sc->sc_wdcdev.sc_atac.atac_cap |= ATAC_CAP_DATA32;
> 
> I would like to add an additional switch based on the capaiblities of the
> pcic (in this case pxa2x0_pcic). What would be the best data structure to
> pass this flag to wdc_pcmcia?

I guess a device property would be appropriate in this case.
The parent sets the property and the device query for the property.
Look for "device_properties" in sys/dev/pci/ for examples.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--