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mac_via.h

/*
 *    6522 Versatile Interface Adapter (VIA)
 *
 *    There are two of these on the Mac II. Some IRQ's are vectored
 *    via them as are assorted bits and bobs - eg rtc, adb. The picture
 *    is a bit incomplete as the Mac documentation doesn't cover this well
 */

#ifndef _ASM_MAC_VIA_H_
#define _ASM_MAC_VIA_H_

/*
 * Base addresses for the VIAs. There are two in every machine,
 * although on some machines the second is an RBV or an OSS.
 * The OSS is different enough that it's handled separately.
 *
 * Do not use these values directly; use the via1 and via2 variables
 * instead (and don't forget to check rbv_present when using via2!)
 */

#define VIA1_BASE (0x50F00000)
#define VIA2_BASE (0x50F02000)
#define  RBV_BASE (0x50F26000)

/*
 *    Not all of these are true post MacII I think.
 *      CSA: probably the ones CHRP marks as 'unused' change purposes
 *      when the IWM becomes the SWIM.
 *      http://www.rs6000.ibm.com/resource/technology/chrpio/via5.mak.html
 *      ftp://ftp.austin.ibm.com/pub/technology/spec/chrp/inwork/CHRP_IORef_1.0.pdf
 *
 * also, http://developer.apple.com/technotes/hw/hw_09.html claims the
 * following changes for IIfx:
 * VIA1A_vSccWrReq not available and that VIA1A_vSync has moved to an IOP.
 * Also, "All of the functionality of VIA2 has been moved to other chips".
 */

#define VIA1A_vSccWrReq 0x80  /* SCC write. (input)
                         * [CHRP] SCC WREQ: Reflects the state of the
                         * Wait/Request pins from the SCC.
                         * [Macintosh Family Hardware]
                         * as CHRP on SE/30,II,IIx,IIcx,IIci.
                         * on IIfx, "0 means an active request"
                         */
#define VIA1A_vRev8     0x40  /* Revision 8 board ???
                                 * [CHRP] En WaitReqB: Lets the WaitReq_L
                         * signal from port B of the SCC appear on
                         * the PA7 input pin. Output.
                         * [Macintosh Family] On the SE/30, this
                         * is the bit to flip screen buffers.
                         * 0=alternate, 1=main.
                         * on II,IIx,IIcx,IIci,IIfx this is a bit
                         * for Rev ID. 0=II,IIx, 1=IIcx,IIci,IIfx
                         */
#define VIA1A_vHeadSel  0x20  /* Head select for IWM.
                         * [CHRP] unused.
                         * [Macintosh Family] "Floppy disk
                         * state-control line SEL" on all but IIfx
                         */
#define VIA1A_vOverlay  0x10    /* [Macintosh Family] On SE/30,II,IIx,IIcx
                         * this bit enables the "Overlay" address
                         * map in the address decoders as it is on
                         * reset for mapping the ROM over the reset
                         * vector. 1=use overlay map.
                         * On the IIci,IIfx it is another bit of the
                         * CPU ID: 0=normal IIci, 1=IIci with parity
                         * feature or IIfx.
                         * [CHRP] En WaitReqA: Lets the WaitReq_L
                         * signal from port A of the SCC appear
                         * on the PA7 input pin (CHRP). Output.
                         * [MkLinux] "Drive Select"
                         *  (with 0x20 being 'disk head select')
                         */
#define VIA1A_vSync     0x08    /* [CHRP] Sync Modem: modem clock select:
                                 * 1: select the external serial clock to
                         *    drive the SCC's /RTxCA pin.
                         * 0: Select the 3.6864MHz clock to drive
                         *    the SCC cell.
                         * [Macintosh Family] Correct on all but IIfx
                         */

/* Macintosh Family Hardware sez: bits 0-2 of VIA1A are volume control
 * on Macs which had the PWM sound hardware.  Reserved on newer models.
 * On IIci,IIfx, bits 1-2 are the rest of the CPU ID:
 * bit 2: 1=IIci, 0=IIfx
 * bit 1: 1 on both IIci and IIfx.
 * MkLinux sez bit 0 is 'burnin flag' in this case.
 * CHRP sez: VIA1A bits 0-2 and 5 are 'unused': if programmed as
 * inputs, these bits will read 0.
 */
#define VIA1A_vVolume   0x07  /* Audio volume mask for PWM */
#define VIA1A_CPUID0    0x02  /* CPU id bit 0 on RBV, others */
#define VIA1A_CPUID1    0x04  /* CPU id bit 0 on RBV, others */
#define VIA1A_CPUID2    0x10  /* CPU id bit 0 on RBV, others */
#define VIA1A_CPUID3    0x40  /* CPU id bit 0 on RBV, others */

/* Info on VIA1B is from Macintosh Family Hardware & MkLinux.
 * CHRP offers no info. */
#define VIA1B_vSound    0x80  /* Sound enable (for compatibility with
                         * PWM hardware) 0=enabled.
                         * Also, on IIci w/parity, shows parity error
                         * 0=error, 1=OK. */
#define VIA1B_vMystery  0x40    /* On IIci, parity enable. 0=enabled,1=disabled
                         * On SE/30, vertical sync interrupt enable.
                         * 0=enabled. This vSync interrupt shows up
                         * as a slot $E interrupt. */
#define VIA1B_vADBS2    0x20  /* ADB state input bit 1 (unused on IIfx) */
#define VIA1B_vADBS1    0x10  /* ADB state input bit 0 (unused on IIfx) */
#define VIA1B_vADBInt   0x08  /* ADB interrupt 0=interrupt (unused on IIfx)*/
#define VIA1B_vRTCEnb   0x04  /* Enable Real time clock. 0=enabled. */
#define VIA1B_vRTCClk   0x02    /* Real time clock serial-clock line. */
#define VIA1B_vRTCData  0x01    /* Real time clock serial-data line. */

/* MkLinux defines the following "VIA1 Register B contents where they
 * differ from standard VIA1".  From the naming scheme, we assume they
 * correspond to a VIA work-alike named 'EVR'. */
#define     EVRB_XCVR   0x08  /* XCVR_SESSION* */
#define     EVRB_FULL   0x10  /* VIA_FULL */
#define     EVRB_SYSES  0x20  /* SYS_SESSION */
#define     EVRB_AUXIE  0x00  /* Enable A/UX Interrupt Scheme */
#define     EVRB_AUXID  0x40  /* Disable A/UX Interrupt Scheme */
#define     EVRB_SFTWRIE      0x00  /* Software Interrupt ReQuest */
#define     EVRB_SFTWRID      0x80  /* Software Interrupt ReQuest */

/*
 *    VIA2 A register is the interrupt lines raised off the nubus
 *    slots.
 *      The below info is from 'Macintosh Family Hardware.'
 *      MkLinux calls the 'IIci internal video IRQ' below the 'RBV slot 0 irq.'
 *      It also notes that the slot $9 IRQ is the 'Ethernet IRQ' and
 *      defines the 'Video IRQ' as 0x40 for the 'EVR' VIA work-alike.
 *      Perhaps OSS uses vRAM1 and vRAM2 for ADB.
 */

#define VIA2A_vRAM1     0x80  /* RAM size bit 1 (IIci: reserved) */
#define VIA2A_vRAM0     0x40  /* RAM size bit 0 (IIci: internal video IRQ) */
#define VIA2A_vIRQE     0x20  /* IRQ from slot $E */
#define VIA2A_vIRQD     0x10  /* IRQ from slot $D */
#define VIA2A_vIRQC     0x08  /* IRQ from slot $C */
#define VIA2A_vIRQB     0x04  /* IRQ from slot $B */
#define VIA2A_vIRQA     0x02  /* IRQ from slot $A */
#define VIA2A_vIRQ9     0x01  /* IRQ from slot $9 */

/* RAM size bits decoded as follows:
 * bit1 bit0  size of ICs in bank A
 *  0    0    256 kbit
 *  0    1    1 Mbit
 *  1    0    4 Mbit
 *  1    1   16 Mbit
 */

/*
 *    Register B has the fun stuff in it
 */

#define VIA2B_vVBL      0x80  /* VBL output to VIA1 (60.15Hz) driven by
                         * timer T1.
                         * on IIci, parity test: 0=test mode.
                         * [MkLinux] RBV_PARODD: 1=odd,0=even. */
#define VIA2B_vSndJck   0x40  /* External sound jack status.
                         * 0=plug is inserted.  On SE/30, always 0 */
#define VIA2B_vTfr0     0x20  /* Transfer mode bit 0 ack from NuBus */
#define VIA2B_vTfr1     0x10  /* Transfer mode bit 1 ack from NuBus */
#define VIA2B_vMode32   0x08  /* 24/32bit switch - doubles as cache flush
                         * on II, AMU/PMMU control.
                         *   if AMU, 0=24bit to 32bit translation
                         *   if PMMU, 1=PMMU is accessing page table.
                         * on SE/30 tied low.
                         * on IIx,IIcx,IIfx, unused.
                         * on IIci/RBV, cache control. 0=flush cache.
                         */
#define VIA2B_vPower    0x04  /* Power off, 0=shut off power.
                         * on SE/30 this signal sent to PDS card. */
#define VIA2B_vBusLk    0x02  /* Lock NuBus transactions, 0=locked.
                         * on SE/30 sent to PDS card. */
#define VIA2B_vCDis     0x01  /* Cache control. On IIci, 1=disable cache card
                         * on others, 0=disable processor's instruction
                         * and data caches. */

/* Apple sez: http://developer.apple.com/technotes/ov/ov_04.html
 * Another example of a valid function that has no ROM support is the use
 * of the alternate video page for page-flipping animation. Since there
 * is no ROM call to flip pages, it is necessary to go play with the
 * right bit in the VIA chip (6522 Versatile Interface Adapter).
 * [CSA: don't know which one this is, but it's one of 'em!]
 */

/*
 *    6522 registers - see databook.
 * CSA: Assignments for VIA1 confirmed from CHRP spec.
 */

/* partial address decode.  0xYYXX : XX part for RBV, YY part for VIA */
/* Note: 15 VIA regs, 8 RBV regs */

#define vBufB     0x0000      /* [VIA/RBV]  Register B */
#define vBufAH    0x0200  /* [VIA only] Buffer A, with handshake. DON'T USE! */
#define vDirB     0x0400  /* [VIA only] Data Direction Register B. */
#define vDirA     0x0600  /* [VIA only] Data Direction Register A. */
#define vT1CL     0x0800  /* [VIA only] Timer one counter low. */
#define vT1CH     0x0a00  /* [VIA only] Timer one counter high. */
#define vT1LL     0x0c00  /* [VIA only] Timer one latches low. */
#define vT1LH     0x0e00  /* [VIA only] Timer one latches high. */
#define vT2CL     0x1000  /* [VIA only] Timer two counter low. */
#define vT2CH     0x1200  /* [VIA only] Timer two counter high. */
#define vSR 0x1400  /* [VIA only] Shift register. */
#define vACR      0x1600  /* [VIA only] Auxilary control register. */
#define vPCR      0x1800  /* [VIA only] Peripheral control register. */
                        /*            CHRP sez never ever to *write* this.
                   *            Mac family says never to *change* this.
                   * In fact we need to initialize it once at start. */
#define vIFR      0x1a00  /* [VIA/RBV]  Interrupt flag register. */
#define vIER      0x1c00  /* [VIA/RBV]  Interrupt enable register. */
#define vBufA     0x1e00  /* [VIA/RBV] register A (no handshake) */

/* The RBV only decodes the bottom eight address lines; the VIA doesn't
 * decode the bottom eight -- so vBufB | rBufB will always get you BufB */
/* CSA: in fact, only bits 0,1, and 4 seem to be decoded.
 * BUT note the values for rIER and rIFR, where the top 8 bits *do* seem
 * to matter.  In fact *all* of the top 8 bits seem to matter;
 * setting rIER=0x1813 and rIFR=0x1803 doesn't work, either.
 * Perhaps some sort of 'compatibility mode' is built-in? [21-May-1999]
 */

#define rBufB   0x0000  /* [VIA/RBV]  Register B */
#define rExp      0x0001      /* [RBV only] RBV future expansion (always 0) */
#define rSIFR     0x0002  /* [RBV only] RBV slot interrupts register. */
#define rIFR      0x1a03  /* [VIA/RBV]  RBV interrupt flag register. */
#define rMonP   0x0010  /* [RBV only] RBV video monitor type. */
#define rChpT   0x0011  /* [RBV only] RBV test mode register (reads as 0). */
#define rSIER   0x0012  /* [RBV only] RBV slot interrupt enables. */
#define rIER    0x1c13  /* [VIA/RBV]  RBV interrupt flag enable register. */
#define rBufA     rSIFR   /* the 'slot interrupts register' is BufA on a VIA */

/*
 * Video monitor parameters, for rMonP:
 */
#define RBV_DEPTH  0x07 /* bits per pixel: 000=1,001=2,010=4,011=8 */
#define RBV_MONID  0x38 /* monitor type, as below. */
#define RBV_VIDOFF 0x40 /* 1 turns off onboard video */
/* Supported monitor types: */
#define MON_15BW   (1<<3) /* 15" BW portrait. */
#define MON_IIGS   (2<<3) /* 12" color (modified IIGS monitor). */
#define MON_15RGB  (5<<3) /* 15" RGB portrait. */
#define MON_12OR13 (6<<3) /* 12" BW or 13" RGB. */
#define MON_NONE   (7<<3) /* No monitor attached. */

/* To clarify IER manipulations */
#define IER_SET_BIT(b) (0x80 | (1<<(b)) )
#define IER_CLR_BIT(b) (0x7F & (1<<(b)) )

#ifndef __ASSEMBLY__

extern volatile __u8 *via1,*via2;
extern int rbv_present,via_alt_mapping;

static inline int rbv_set_video_bpp(int bpp)
{
      char val = (bpp==1)?0:(bpp==2)?1:(bpp==4)?2:(bpp==8)?3:-1;
      if (!rbv_present || val<0) return -1;
      via2[rMonP] = (via2[rMonP] & ~RBV_DEPTH) | val;
      return 0;
}

#endif /* __ASSEMBLY__ */

#endif /* _ASM_MAC_VIA_H_ */

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