/* SPDX-License-Identifier: GPL-2.0 */
/* sun3xflop.h: Sun3/80 specific parts of the floppy driver.
 *
 * Derived partially from asm-sparc/floppy.h, which is:
 *     Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
 *
 * Sun3x version 2/4/2000 Sam Creasey (sammy@sammy.net)
 */

#ifndef __ASM_SUN3X_FLOPPY_H
#define __ASM_SUN3X_FLOPPY_H

#include <linux/pgtable.h>
#include <asm/page.h>
#include <asm/irq.h>
#include <asm/sun3x.h>

/* default interrupt vector */
#define SUN3X_FDC_IRQ 0x40

/* some constants */
#define FCR_TC 0x1
#define FCR_EJECT 0x2
#define FCR_MTRON 0x4
#define FCR_DSEL1 0x8
#define FCR_DSEL0 0x10

/* We don't need no stinkin' I/O port allocation crap. */
#undef release_region
#undef request_region
#define release_region(X, Y)    do { } while(0)
#define request_region(X, Y, Z) (1)

struct sun3xflop_private {
        volatile unsigned char *status_r;
        volatile unsigned char *data_r;
        volatile unsigned char *fcr_r;
        volatile unsigned char *fvr_r;
        unsigned char fcr;
} sun3x_fdc;

/* Super paranoid... */
#undef HAVE_DISABLE_HLT

/* Routines unique to each controller type on a Sun. */
static unsigned char sun3x_82072_fd_inb(int port)
{
        static int once = 0;
//      udelay(5);
        switch(port & 7) {
        default:
                pr_crit("floppy: Asked to read unknown port %d\n", port);
                panic("floppy: Port bolixed.");
        case 4: /* FD_STATUS */
                return (*sun3x_fdc.status_r) & ~STATUS_DMA;
        case 5: /* FD_DATA */
                return (*sun3x_fdc.data_r);
        case 7: /* FD_DIR */
                /* ugly hack, I can't find a way to actually detect the disk */
                if(!once) {
                        once = 1;
                        return 0x80;
                }
                return 0;
        };
        panic("sun_82072_fd_inb: How did I get here?");
}

static void sun3x_82072_fd_outb(unsigned char value, int port)
{
//      udelay(5);
        switch(port & 7) {
        default:
                pr_crit("floppy: Asked to write to unknown port %d\n", port);
                panic("floppy: Port bolixed.");
        case 2: /* FD_DOR */
                /* Oh geese, 82072 on the Sun has no DOR register,
                 * so we make do with taunting the FCR.
                 *
                 * ASSUMPTIONS:  There will only ever be one floppy
                 *               drive attached to a Sun controller
                 *               and it will be at drive zero.
                 */

        {
                unsigned char fcr = sun3x_fdc.fcr;

                if(value & 0x10) {
                        fcr |= (FCR_DSEL0 | FCR_MTRON);
                } else
                        fcr &= ~(FCR_DSEL0 | FCR_MTRON);


                if(fcr != sun3x_fdc.fcr) {
                        *(sun3x_fdc.fcr_r) = fcr;
                        sun3x_fdc.fcr = fcr;
                }
        }
                break;
        case 5: /* FD_DATA */
                *(sun3x_fdc.data_r) = value;
                break;
        case 7: /* FD_DCR */
                *(sun3x_fdc.status_r) = value;
                break;
        case 4: /* FD_STATUS */
                *(sun3x_fdc.status_r) = value;
                break;
        }
        return;
}


asmlinkage irqreturn_t sun3xflop_hardint(int irq, void *dev_id)
{
        register unsigned char st;

#undef TRACE_FLPY_INT
#define NO_FLOPPY_ASSEMBLER

#ifdef TRACE_FLPY_INT
        static int calls=0;
        static int bytes=0;
        static int dma_wait=0;
#endif
        if(!doing_pdma) {
                floppy_interrupt(irq, dev_id);
                return IRQ_HANDLED;
        }

//      pr_info("doing pdma\n");// st %x\n", sun_fdc->status_82072);

#ifdef TRACE_FLPY_INT
        if(!calls)
                bytes = virtual_dma_count;
#endif

        {
                register int lcount;
                register char *lptr;

                for(lcount=virtual_dma_count, lptr=virtual_dma_addr;
                    lcount; lcount--, lptr++) {
/*                      st=fd_inb(virtual_dma_port+4) & 0x80 ;  */
                        st = *(sun3x_fdc.status_r);
/*                      if(st != 0xa0)                  */
/*                              break;                  */

                        if((st & 0x80) == 0) {
                                virtual_dma_count = lcount;
                                virtual_dma_addr = lptr;
                                return IRQ_HANDLED;
                        }

                        if((st & 0x20) == 0)
                                break;

                        if(virtual_dma_mode)
/*                              fd_outb(*lptr, virtual_dma_port+5); */
                                *(sun3x_fdc.data_r) = *lptr;
                        else
/*                              *lptr = fd_inb(virtual_dma_port+5); */
                                *lptr = *(sun3x_fdc.data_r);
                }

                virtual_dma_count = lcount;
                virtual_dma_addr = lptr;
/*              st = fd_inb(virtual_dma_port+4);   */
                st = *(sun3x_fdc.status_r);
        }

#ifdef TRACE_FLPY_INT
        calls++;
#endif
//      pr_info("st=%02x\n", st);
        if(st == 0x20)
                return IRQ_HANDLED;
        if(!(st & 0x20)) {
                virtual_dma_residue += virtual_dma_count;
                virtual_dma_count=0;
                doing_pdma = 0;

#ifdef TRACE_FLPY_INT
                pr_info("count=%x, residue=%x calls=%d bytes=%x dma_wait=%d\n",
                        virtual_dma_count, virtual_dma_residue, calls, bytes,
                        dma_wait);
                calls = 0;
                dma_wait=0;
#endif

                floppy_interrupt(irq, dev_id);
                return IRQ_HANDLED;
        }


#ifdef TRACE_FLPY_INT
        if(!virtual_dma_count)
                dma_wait++;
#endif
        return IRQ_HANDLED;
}

static int sun3xflop_request_irq(void)
{
        static int once = 0;
        int error;

        if(!once) {
                once = 1;
                error = request_irq(FLOPPY_IRQ, sun3xflop_hardint,
                                    0, "floppy", NULL);
                return ((error == 0) ? 0 : -1);
        } else return 0;
}

static void __init floppy_set_flags(int *ints,int param, int param2);

static int sun3xflop_init(void)
{
        if(FLOPPY_IRQ < 0x40)
                FLOPPY_IRQ = SUN3X_FDC_IRQ;

        sun3x_fdc.status_r = (volatile unsigned char *)SUN3X_FDC;
        sun3x_fdc.data_r  = (volatile unsigned char *)(SUN3X_FDC+1);
        sun3x_fdc.fcr_r = (volatile unsigned char *)SUN3X_FDC_FCR;
        sun3x_fdc.fvr_r = (volatile unsigned char *)SUN3X_FDC_FVR;
        sun3x_fdc.fcr = 0;

        /* Last minute sanity check... */
        if(*sun3x_fdc.status_r == 0xff) {
                return -1;
        }

        *sun3x_fdc.fvr_r = FLOPPY_IRQ;

        *sun3x_fdc.fcr_r = FCR_TC;
        udelay(10);
        *sun3x_fdc.fcr_r = 0;

        /* Success... */
        floppy_set_flags(NULL, 1, FD_BROKEN_DCL); // I don't know how to detect this.
        allowed_drive_mask = 0x01;
        return (int) SUN3X_FDC;
}

/* I'm not precisely sure this eject routine works */
static int sun3x_eject(void)
{
        if(MACH_IS_SUN3X) {

                sun3x_fdc.fcr |= (FCR_DSEL0 | FCR_EJECT);
                *(sun3x_fdc.fcr_r) = sun3x_fdc.fcr;
                udelay(10);
                sun3x_fdc.fcr &= ~(FCR_DSEL0 | FCR_EJECT);
                *(sun3x_fdc.fcr_r) = sun3x_fdc.fcr;
        }

        return 0;
}

#define fd_eject(drive) sun3x_eject()

#endif /* !(__ASM_SUN3X_FLOPPY_H) */