[linux-cirrus] Re: How to determine if a device is an AMBA device
- From: Jean-Philippe Francois <jp.francois@xxxxxxxxxx>
- To: linux-cirrus@xxxxxxxxxxxxx
- Date: Wed, 27 Jun 2007 17:36:09 +0200
Wagner Scott (ST-IN/ENG1.1) a écrit :
Hello all,
It is not clear to me what it means to be an AMBA device.
Russell King alluded to this in his post
http://lists.arm.linux.org.uk/pipermail/linux-arm/2006-August/012098.htm
l: "Only use an amba_device _IF_ you have a real AMBA device. It's not
for willy nilly random drivers."
The case for which I am confused is an external peripheral connected to
a Cirrus Logic EP93xx (ARM920T) address & data bus using the EP93xx
static memory controller and one of the external interrupts (/INT1).
Is this an AMBA device, which should use amba_driver_register(),
amba_device_register(), and friends in ./arch/arm/common/amba.c and
./include/asm/hardware/amba.h, (since it uses the EP93xx's AMBA static
memory and interrupt controllers)?
See this http://lxr.linux.no/source/arch/arm/mach-ep93xx/core.c?a=arm
the uart inside the chip are AMBA devices, but other devices are
platform_devices,
registered using platform_device_register and platform_driver_register.
Or is it an "ordinary" device which should use the generic Linux
ioremap_nocache() and request_irq() mechanism, as Russell suggests?
Yep, except you should not call ioremap but let platform_device_register
do it for you.
Thanks in advance for any advice.
Scott Wagner
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