Looking for a driver for Compact Flash access - Embedded
This is a discussion on Looking for a driver for Compact Flash access - Embedded ; Hi,
I'm have an embedded system using Compact Flash device.
I'm trying to figure out what is the right driver to access the CF.
The HW configuration is as following:
The CF is connected directly to MPC8541 CPU (PowerQUICC III,
...
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Looking for a driver for Compact Flash access
Hi,
I'm have an embedded system using Compact Flash device.
I'm trying to figure out what is the right driver to access the CF.
The HW configuration is as following:
The CF is connected directly to MPC8541 CPU (PowerQUICC III,
Freescale), via local bus.
It is connected in Memory Mode, with 8-bit interface.
The questions I have:
1. What is the appropriate driver? Since memory mode is PCMCIA-
compatible PC Card ATA, I assume it is ide-cs. Is it right?
2. The card doesn't issue interrupts in this mode. I got the
impression the IDE driver relies on interrupts. Does it make it
unusable for accessing a CF in Memory Mode?
Most grateful for your help,
Michael
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Re: Looking for a driver for Compact Flash access
Mic wrote:
> Hi,
> I'm have an embedded system using Compact Flash device.
> I'm trying to figure out what is the right driver to access the CF.
>
> The HW configuration is as following:
> The CF is connected directly to MPC8541 CPU (PowerQUICC III,
> Freescale), via local bus.
> It is connected in Memory Mode, with 8-bit interface.
>
> The questions I have:
> 1. What is the appropriate driver? Since memory mode is PCMCIA-
> compatible PC Card ATA, I assume it is ide-cs. Is it right?
>
> 2. The card doesn't issue interrupts in this mode. I got the
> impression the IDE driver relies on interrupts. Does it make it
> unusable for accessing a CF in Memory Mode?
>
>
> Most grateful for your help,
> Michael
>
Is this your own design or did you purchase this board from somewhere ??
What Operating system are you using ?
A little more info about the design of this board would be nice.
donald
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Re: Looking for a driver for Compact Flash access
As the CF uses a standard IDE interface, the IDE driver for the hardware
in question should work.
-Michael
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Re: Looking for a driver for Compact Flash access
On Apr 5, 6:37 pm, Donald wrote:
> Mic wrote:
> > Hi,
> > I'm have an embedded system using Compact Flash device.
> > I'm trying to figure out what is the right driver to access the CF.
>
> > The HW configuration is as following:
> > The CF is connected directly to MPC8541 CPU (PowerQUICC III,
> > Freescale), via local bus.
> > It is connected in Memory Mode, with 8-bit interface.
>
> > The questions I have:
> > 1. What is the appropriate driver? Since memory mode is PCMCIA-
> > compatible PC Card ATA, I assume it is ide-cs. Is it right?
>
> > 2. The card doesn't issue interrupts in this mode. I got the
> > impression the IDE driver relies on interrupts. Does it make it
> > unusable for accessing a CF in Memory Mode?
>
> > Most grateful for your help,
> > Michael
>
> Is this your own design or did you purchase this board from somewhere ??
>
> What Operating system are you using ?
>
> A little more info about the design of this board would be nice.
>
> donald- Hide quoted text -
>
> - Show quoted text -
Hi.
1. This is my our own design. Do you think connecting the CF in other
mode (IO/IDE) will make things consederably easier? Even so, is it
doable also in memory-mode connection?
2. Sorry - I should've mentioned it. It is Linux (2.6.14).
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Re: Looking for a driver for Compact Flash access
On Apr 5, 6:06 pm, Michael Schnell
wrote:
> As the CF uses a standard IDE interface, the IDE driver for the hardware
> in question should work.
>
> -Michael
The problems I have using an IDE driver are:
1. Looks like the IDE driver relys on interrupt-driven IO, and the CF
does not issue any interrupts when connected in memory mode.
2. I'm not sure which one to choose: ide-cs (but then, I don't have
IDE-controller), ide-ata? I guess some adaptation will be necessary in
any case, right now I don't know what it is and what is the closest
driver to what I need.
Thanks,
Michael.
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Re: Looking for a driver for Compact Flash access
Ah, I see that you have a non-standard hardware with no existing IDE
driver.
I would try to modify the IDE driver (from PPC or ARM if you use a
memory mapped hardware).
Of course, if your hardware does not use interrupts, the performance of
the driver will not be very good, as you will need to use polling
instead. But modifying the driver by using a Kernel timer, polling the
original interrupting pin of the IDE interface, instead of an interrupt
should not introduce a too massive change.
-Michael
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Re: Looking for a driver for Compact Flash access
On Apr 8, 9:38 am, Michael Schnell
wrote:
> Ah, I see that you have a non-standard hardware with no existing IDE
> driver.
>
> I would try to modify the IDE driver (from PPC or ARM if you use a
> memory mapped hardware).
>
> Of course, if your hardware does not use interrupts, the performance of
> the driver will not be very good, as you will need to use polling
> instead. But modifying the driver by using a Kernel timer, polling the
> original interrupting pin of the IDE interface, instead of an interrupt
> should not introduce a too massive change.
>
> -Michael
Yes, looks like this is the general direction...
I'm still trying to find my way there. What do you mean by an IDE
driver from PPC?
>From what I see, the ide.c is a generic layer, and you need to
register the specific read/write etc. functions with it.
Can you please help me with narrowing-down the search for the
potential modules to change (i.e. some "vanila" ide module I can use
as a basis), or some good reference on how to add an IDE device?
Thanks,
Michael
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Re: Looking for a driver for Compact Flash access
Mic wrote:
> On Apr 8, 9:38 am, Michael Schnell
> wrote:
>>From what I see, the ide.c is a generic layer, and you need to
> register the specific read/write etc. functions with it.
> Can you please help me with narrowing-down the search for the
> potential modules to change (i.e. some "vanila" ide module I can use
> as a basis), or some good reference on how to add an IDE device?
http://dslinux.gits.kiev.ua/trunk/li.../arm/ide_arm.c
regards
Wolfgang
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Re: Looking for a driver for Compact Flash access
On Apr 8, 12:06 pm, Wolfgang Mües wrote:
> Mic wrote:
> > On Apr 8, 9:38 am, Michael Schnell
> > wrote:
> >>From what I see, the ide.c is a generic layer, and you need to
> > register the specific read/write etc. functions with it.
> > Can you please help me with narrowing-down the search for the
> > potential modules to change (i.e. some "vanila" ide module I can use
> > as a basis), or some good reference on how to add an IDE device?
>
> http://dslinux.gits.kiev.ua/trunk/li.../arm/ide_arm.c
>
> regards
>
> Wolfgang
Thanks
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Looking for a driver for Compact Flash memory mapped mode with polling(no IRQ)
Hi,
I am having an embedded system using Compact Flash device.
I am trying to figure out what is the right driver to access the CF.
The HW configuration is as following:
The CF(Sandisk) is connected directly to MPC8250 CPU (PowerQUICC II,
Freescale), via local bus(Direct access like SDRAM).
It is connected in Memory mapped Mode, with 16-bit interface.
My linux version is 2.6.22 with ARCH as ppc.
The questions I have:
1. Is there any driver avilable in 2.6.22 to support this kind of access?
2. I have one u-boot proprietry driver which support raw device access of CF?
can this be be ported in to linux and use it? Is there any procedure to follow?
Could anybody please guide me how to go about?
Thanks in advance