sparc32: Add more extensive documentation of sun4m interrupts. Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> --- arch/sparc/kernel/sun4m_irq.c | 53 +++++++++++++++++++++++++++++++++++++++++ 1 files changed, 53 insertions(+), 0 deletions(-) diff --git a/arch/sparc/kernel/sun4m_irq.c b/arch/sparc/kernel/sun4m_irq.c index c6096fc..ec66d4a 100644 --- a/arch/sparc/kernel/sun4m_irq.c +++ b/arch/sparc/kernel/sun4m_irq.c @@ -87,6 +87,59 @@ struct sun4m_irq_global __iomem *sun4m_irq_global; #define SUN4M_INT_SBUS(x) (1 << (x+7)) #define SUN4M_INT_VME(x) (1 << (x)) +/* Interrupt level assignment on sun4m: + * + * level source + * ------------------------------------------------------------ + * 1 softint-1 + * 2 softint-2, VME/SBUS level 1 + * 3 softint-3, VME/SBUS level 2 + * 4 softint-4, onboard SCSI + * 5 softint-5, VME/SBUS level 3 + * 6 softint-6, onboard ETHERNET + * 7 softint-7, VME/SBUS level 4 + * 8 softint-8, onboard VIDEO + * 9 softint-9, VME/SBUS level 5, Module Interrupt + * 10 softint-10, system counter/timer + * 11 softint-11, VME/SBUS level 6, Floppy + * 12 softint-12, Keyboard/Mouse, Serial + * 13 softint-13, VME/SBUS level 7, ISDN Audio + * 14 softint-14, per-processor counter/timer + * 15 softint-15, Asynchronous Errors (broadcast) + * + * Each interrupt source is masked distinctly in the sun4m interrupt + * registers. The PIL level alone is therefore ambiguous, since multiple + * interrupt sources map to a single PIL. + * + * This ambiguity is resolved in the 'intr' property for device nodes + * in the OF device tree. Each 'intr' property entry is composed of + * two 32-bit words. The first word is the IRQ priority value, which + * is what we're intersted in. The second word is the IRQ vector, which + * is unused. + * + * The low 4 bits of the IRQ priority indicate the PIL, and the upper + * 4 bits indicate onboard vs. SBUS leveled vs. VME leveled. 0x20 + * means onboard, 0x30 means SBUS leveled, and 0x40 means VME leveled. + * + * For example, an 'intr' IRQ priority value of 0x24 is onboard SCSI + * whereas a value of 0x33 is SBUS level 2. Here are some sample + * 'intr' property IRQ priority values from ss4, ss5, ss10, ss20, and + * Tadpole S3 GX systems. + * + * esp: 0x24 onboard ESP SCSI + * le: 0x26 onboard Lance ETHERNET + * p9100: 0x32 SBUS level 1 P9100 video + * bpp: 0x33 SBUS level 2 BPP parallel port device + * DBRI: 0x39 SBUS level 5 DBRI ISDN audio + * SUNW,leo: 0x39 SBUS level 5 LEO video + * pcmcia: 0x3b SBUS level 6 PCMCIA controller + * uctrl: 0x3b SBUS level 6 UCTRL device + * modem: 0x3d SBUS level 7 MODEM + * zs: 0x2c onboard keyboard/mouse/serial + * floppy: 0x2b onboard Floppy + * power: 0x22 onboard power device (XXX unknown mask bit XXX) + */ + /* These tables only apply for interrupts greater than 15.. * * any intr value below 0x10 is considered to be a soft-int -- 1.5.6.5 -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
