EPIC Vs OpenPIC (RFC)

[Sarnath Kannan]

Somehow I feel that Patching or changing
the openPIC code would make it shabby.
 Why should we change open_pic code,
just because that EPIC is non-conforming ?
The best is to rewrite open_pic code for
EPIC. ( ofcourse, we can reuse code. )
 I dont find anything wrong with open_pic
interface. If people dont follow standards,
we dont make standards comply with them. We
make them comply with standards.

Sarnath

On Sat, 03 Nov 2001 Dag Nygren wrote :
>
> > Mark A. Greer wrote:
> >
> >
> > This is along the lines that I was thinking except
> add a struct member to specify
> > whether edge or level sensitive--i.e., separate
> members for hi/lo and edge/level
>
> Actually this evolved after I posted it :-), after I
> started
> to modify open_pic.c
>
> > What exactly is the "IrqEnable" for?  Is this so you
> can set up the IRQ but not
> > enable it?  Then the driver can enable it later and
> its set up correctly (e.g.,
> > I2C)??
>
> Not really, it was more or less a mistake in the first
> draft. Would there be a
> need
> for that ?
>
> > Doesn't the new struct eliminate the need for
> "RegOffset"?
>
> Have to think about that when implementing the stuff.
>
> >  And as you noted,
> > "programmer_switch_irq" probably isn't needed either.
>  Right?
>
> Yep, and I also came up with another scheme for the
> cascading as the
> special handling for chrp is actually.....drum roll....
> a cascade!
> And it would remove the i8259 refs from the openpic
> stuff.
>
> > If you're up to it, how about implementing, testing,
> then posting a patch for
> > everyone to check out??
>
> I'm trying, but I am a bit scared of destroying too
> much of the open_pic
> code...
>
> Here is the newest suggestion for that interface:
>
> typedef enum irq_polarity_en {
>     OP_IRQ_POS = 1,
>     OP_IRQ_NEG = 0
> } irq_polarity_type;
>
> typedef enum irq_sense_en {
>     OP_IRQ_LEVEL = 1,
>     OP_IRQ_EDGE  = 0
> } irq_sense_type;
>
> typedef struct op
         PICIrq;
>     u_int               Vector;
>     u_char              Priority;
>     irq_sense_type      IrqSense;
>     irq_polarity_type   IrqPolarity;
>     irq_polarity_type   IrqPolarity;
>     int                 (*CascadeHandler)();
> } openpic_irq_def;
>
> typedef struct openpic_def_str {
>     struct OpenPIC  *OpenPIC_Addr;
>     int             main_pic;
>     u_char          RegOffset; /* 0 for "standard", 16
> for MPC107 */
>     int             programmer_switch_irq;
>     openpic_irq_def *IRQdef;    /* The lovest vector
> first in the table !!! */
> } openpic_def;
>
> Comments?
>
>
> Dag
>
>
>


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