Re: EPIC Vs OpenPIC (RFC)

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 openpic_irq_def_str {
    u_int               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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