linuxsh-dev

HD64461 pcmcia driver

[Kristoffer E. <kri...@gm...>]

Paul,

Im fixing up the hd64461 pcmcia driver. Got a quick question.

The hd64461 have two slots (CF/PCMCIA) but since CF is handled by libata (and initial start in hd64461.c) should this driver be able to handle both CF and PCMCIA?

Personally i feel it would make more sense if it only controlled the pcmcia. Anyone wanting
CF support could easily add that for their platform.

Before we never used the CF slot but instead let ide-sh handle it.

Best wishes
Kristoffer

Re: HD64461 pcmcia driver

[Paul M. <le...@li...>]

On Tue, Aug 28, 2007 at 08:03:50PM -0700, Kristoffer Ericson wrote:
> The hd64461 have two slots (CF/PCMCIA) but since CF is handled by
> libata (and initial start in hd64461.c) should this driver be able to
> handle both CF and PCMCIA?
> 
> Personally i feel it would make more sense if it only controlled the
> pcmcia. Anyone wanting CF support could easily add that for their
> platform.
> 
> Before we never used the CF slot but instead let ide-sh handle it.
> 
I'm not sure I understand your question. HD64461 is a multi-function
device, meaning that you have a driver for each defined function. Usually
these need to chain in to the MFD driver for things like IRQ demux and
things like that, but each function is generally wholly isolated.

See things like drivers/mfd/sm501.c and friends for how to work with this
sort of stuff from the driver model. The PCMCIA function of HD64461 has
nothing to do with the CF/pata_platform integration, and it's handled
through an entirely different driver. HD64465 is the same.

Re: HD64461 pcmcia driver

[Kristoffer E. <kri...@gm...>]

On Wed, 29 Aug 2007 18:09:47 +0900
Paul Mundt <le...@li...> wrote:

> On Tue, Aug 28, 2007 at 08:03:50PM -0700, Kristoffer Ericson wrote:
> > The hd64461 have two slots (CF/PCMCIA) but since CF is handled by
> > libata (and initial start in hd64461.c) should this driver be able to
> > handle both CF and PCMCIA?
> > 
> > Personally i feel it would make more sense if it only controlled the
> > pcmcia. Anyone wanting CF support could easily add that for their
> > platform.
> > 
> > Before we never used the CF slot but instead let ide-sh handle it.
> > 
> I'm not sure I understand your question. HD64461 is a multi-function
> device, meaning that you have a driver for each defined function. Usually
> these need to chain in to the MFD driver for things like IRQ demux and
> things like that, but each function is generally wholly isolated.
I put my words poorly, what I ment was, is it resonable that the hd64461_SS driver should
handle the CF slot aswell as the pcmcia one?
Currently its set to only handle the pcmcia, but you can through menuconfig make it also
control the CF slot.


> 
> See things like drivers/mfd/sm501.c and friends for how to work with this
> sort of stuff from the driver model. The PCMCIA function of HD64461 has
> nothing to do with the CF/pata_platform integration, and it's handled
> through an entirely different driver. HD64465 is the same.

Re: HD64461 pcmcia driver

[Paul M. <le...@li...>]

On Wed, Aug 29, 2007 at 06:06:00PM -0700, Kristoffer Ericson wrote:
> On Wed, 29 Aug 2007 18:09:47 +0900
> Paul Mundt <le...@li...> wrote:
> 
> > On Tue, Aug 28, 2007 at 08:03:50PM -0700, Kristoffer Ericson wrote:
> > > The hd64461 have two slots (CF/PCMCIA) but since CF is handled by
> > > libata (and initial start in hd64461.c) should this driver be able to
> > > handle both CF and PCMCIA?
> > > 
> > > Personally i feel it would make more sense if it only controlled the
> > > pcmcia. Anyone wanting CF support could easily add that for their
> > > platform.
> > > 
> > > Before we never used the CF slot but instead let ide-sh handle it.
> > > 
> > I'm not sure I understand your question. HD64461 is a multi-function
> > device, meaning that you have a driver for each defined function. Usually
> > these need to chain in to the MFD driver for things like IRQ demux and
> > things like that, but each function is generally wholly isolated.
> I put my words poorly, what I ment was, is it resonable that the hd64461_SS driver should
> handle the CF slot aswell as the pcmcia one?
> Currently its set to only handle the pcmcia, but you can through menuconfig make it also
> control the CF slot.
> 
For storage devices it doesn't really matter, but keep in mind that there
are also non-storage CF devices, so you may want to handle both cases. I
would focus on PCMCIA first and worry about the corner cases later,
however.

Re: HD64461 pcmcia driver

[Kristoffer E. <kri...@gm...>]

On Thu, 30 Aug 2007 09:02:20 +0900
Paul Mundt <le...@li...> wrote:

> On Wed, Aug 29, 2007 at 06:06:00PM -0700, Kristoffer Ericson wrote:
> > On Wed, 29 Aug 2007 18:09:47 +0900
> > Paul Mundt <le...@li...> wrote:
> > 
> > > On Tue, Aug 28, 2007 at 08:03:50PM -0700, Kristoffer Ericson wrote:
> > > > The hd64461 have two slots (CF/PCMCIA) but since CF is handled by
> > > > libata (and initial start in hd64461.c) should this driver be able to
> > > > handle both CF and PCMCIA?
> > > > 
> > > > Personally i feel it would make more sense if it only controlled the
> > > > pcmcia. Anyone wanting CF support could easily add that for their
> > > > platform.
> > > > 
> > > > Before we never used the CF slot but instead let ide-sh handle it.
> > > > 
> > > I'm not sure I understand your question. HD64461 is a multi-function
> > > device, meaning that you have a driver for each defined function. Usually
> > > these need to chain in to the MFD driver for things like IRQ demux and
> > > things like that, but each function is generally wholly isolated.
> > I put my words poorly, what I ment was, is it resonable that the hd64461_SS driver should
> > handle the CF slot aswell as the pcmcia one?
> > Currently its set to only handle the pcmcia, but you can through menuconfig make it also
> > control the CF slot.
> > 
> For storage devices it doesn't really matter, but keep in mind that there
> are also non-storage CF devices, so you may want to handle both cases. I
> would focus on PCMCIA first and worry about the corner cases later,
> however.
Thats the thing, the CF slot can only handle memory/storage card (hardware limitation). So, if I drop support for the CF slot in hd64461_ss users shouldn't miss anything. Thats why Im so eager to get rid of it in hd64461_ss, since it feels like un-needed support.