void __init via_init()

in mac/via.c [111:259]

• 94 lines of code
• 19 McCabe index (conditional complexity)

void __init via_init(void)
{
	via1 = (void *)VIA1_BASE;
	pr_debug("VIA1 detected at %p\n", via1);

	if (oss_present) {
		via2 = NULL;
		rbv_present = 0;
	} else {
		switch (macintosh_config->via_type) {

		/* IIci, IIsi, IIvx, IIvi (P6xx), LC series */

		case MAC_VIA_IICI:
			via2 = (void *)RBV_BASE;
			pr_debug("VIA2 (RBV) detected at %p\n", via2);
			rbv_present = 1;
			if (macintosh_config->ident == MAC_MODEL_LCIII) {
				rbv_clear = 0x00;
			} else {
				/* on most RBVs (& unlike the VIAs), you   */
				/* need to set bit 7 when you write to IFR */
				/* in order for your clear to occur.       */
				rbv_clear = 0x80;
			}
			gIER = rIER;
			gIFR = rIFR;
			gBufA = rSIFR;
			gBufB = rBufB;
			break;

		/* Quadra and early MacIIs agree on the VIA locations */

		case MAC_VIA_QUADRA:
		case MAC_VIA_II:
			via2 = (void *) VIA2_BASE;
			pr_debug("VIA2 detected at %p\n", via2);
			rbv_present = 0;
			rbv_clear = 0x00;
			gIER = vIER;
			gIFR = vIFR;
			gBufA = vBufA;
			gBufB = vBufB;
			break;

		default:
			panic("UNKNOWN VIA TYPE");
		}
	}

#ifdef DEBUG_VIA
	via_debug_dump();
#endif

	/*
	 * Shut down all IRQ sources, reset the timers, and
	 * kill the timer latch on VIA1.
	 */

	via1[vIER] = 0x7F;
	via1[vIFR] = 0x7F;
	via1[vT1CL] = 0;
	via1[vT1CH] = 0;
	via1[vT2CL] = 0;
	via1[vT2CH] = 0;
	via1[vACR] &= ~0xC0; /* setup T1 timer with no PB7 output */
	via1[vACR] &= ~0x03; /* disable port A & B latches */

	/*
	 * SE/30: disable video IRQ
	 */

	if (macintosh_config->ident == MAC_MODEL_SE30) {
		via1[vDirB] |= 0x40;
		via1[vBufB] |= 0x40;
	}

	switch (macintosh_config->adb_type) {
	case MAC_ADB_IOP:
	case MAC_ADB_II:
	case MAC_ADB_PB1:
		/*
		 * Set the RTC bits to a known state: all lines to outputs and
		 * RTC disabled (yes that's 0 to enable and 1 to disable).
		 */
		via1[vDirB] |= VIA1B_vRTCEnb | VIA1B_vRTCClk | VIA1B_vRTCData;
		via1[vBufB] |= VIA1B_vRTCEnb | VIA1B_vRTCClk;
		break;
	}

	/* Everything below this point is VIA2/RBV only... */

	if (oss_present)
		return;

	if ((macintosh_config->via_type == MAC_VIA_QUADRA) &&
	    (macintosh_config->adb_type != MAC_ADB_PB1) &&
	    (macintosh_config->adb_type != MAC_ADB_PB2) &&
	    (macintosh_config->ident    != MAC_MODEL_C660) &&
	    (macintosh_config->ident    != MAC_MODEL_Q840)) {
		via_alt_mapping = 1;
		via1[vDirB] |= 0x40;
		via1[vBufB] &= ~0x40;
	} else {
		via_alt_mapping = 0;
	}

	/*
	 * Now initialize VIA2. For RBV we just kill all interrupts;
	 * for a regular VIA we also reset the timers and stuff.
	 */

	via2[gIER] = 0x7F;
	via2[gIFR] = 0x7F | rbv_clear;
	if (!rbv_present) {
		via2[vT1CL] = 0;
		via2[vT1CH] = 0;
		via2[vT2CL] = 0;
		via2[vT2CH] = 0;
		via2[vACR] &= ~0xC0; /* setup T1 timer with no PB7 output */
		via2[vACR] &= ~0x03; /* disable port A & B latches */
	}

	via_nubus_init();

	/* Everything below this point is VIA2 only... */

	if (rbv_present)
		return;

	/*
	 * Set vPCR for control line interrupts.
	 *
	 * CA1 (SLOTS IRQ), CB1 (ASC IRQ): negative edge trigger.
	 *
	 * Macs with ESP SCSI have a negative edge triggered SCSI interrupt.
	 * Testing reveals that PowerBooks do too. However, the SE/30
	 * schematic diagram shows an active high NCR5380 IRQ line.
	 */

	pr_debug("VIA2 vPCR is 0x%02X\n", via2[vPCR]);
	if (macintosh_config->via_type == MAC_VIA_II) {
		/* CA2 (SCSI DRQ), CB2 (SCSI IRQ): indep. input, pos. edge */
		via2[vPCR] = 0x66;
	} else {
		/* CA2 (SCSI DRQ), CB2 (SCSI IRQ): indep. input, neg. edge */
		via2[vPCR] = 0x22;
	}
}