// SPDX-License-Identifier: GPL-2.0-only
/* Low-level parallel port routines for the Multiface 3 card
 *
 * Author: Joerg Dorchain <joerg@dorchain.net>
 *
 * (C) The elitist m68k Users(TM)
 *
 * based on the existing parport_amiga and lp_mfc
 *
 *
 * From the MFC3 documentation:
 * 
 * Miscellaneous PIA Details
 * -------------------------
 * 
 *      The two open-drain interrupt outputs /IRQA and /IRQB are routed to
 * /INT2 of the Z2 bus.
 * 
 *      The CPU data bus of the PIA (D0-D7) is connected to D8-D15 on the Z2
 * bus. This means that any PIA registers are accessed at even addresses.
 * 
 * Centronics Pin Connections for the PIA
 * --------------------------------------
 * 
 *      The following table shows the connections between the PIA and the
 * Centronics interface connector. These connections implement a single, but
 * very complete, Centronics type interface. The Pin column gives the pin
 * numbers of the PIA. The Centronics pin numbers can be found in the section
 * "Parallel Connectors".
 * 
 * 
 *    Pin | PIA | Dir | Centronics Names
 * -------+-----+-----+---------------------------------------------------------
 *     19 | CB2 | --> | /STROBE (aka /DRDY)
 *  10-17 | PBx | <-> | DATA0 - DATA7
 *     18 | CB1 | <-- | /ACK
 *     40 | CA1 | <-- | BUSY
 *      3 | PA1 | <-- | PAPER-OUT (aka POUT)
 *      4 | PA2 | <-- | SELECTED (aka SEL)
 *      9 | PA7 | --> | /INIT (aka /RESET or /INPUT-PRIME)
 *      6 | PA4 | <-- | /ERROR (aka /FAULT)
 *      7 | PA5 | --> | DIR (aka /SELECT-IN)
 *      8 | PA6 | --> | /AUTO-FEED-XT
 *     39 | CA2 | --> | open
 *      5 | PA3 | <-- | /ACK (same as CB1!)
 *      2 | PA0 | <-- | BUSY (same as CA1!)
 * -------+-----+-----+---------------------------------------------------------
 * 
 * Should be enough to understand some of the driver.
 *
 * Per convention for normal use the port registers are visible.
 * If you need the data direction registers, restore the value in the
 * control register.
 */

#include "multiface.h"
#include <linux/module.h>
#include <linux/init.h>
#include <linux/parport.h>
#include <linux/delay.h>
#include <linux/mc6821.h>
#include <linux/zorro.h>
#include <linux/interrupt.h>
#include <asm/setup.h>
#include <asm/amigahw.h>
#include <asm/irq.h>
#include <asm/amigaints.h>

/* Maximum Number of Cards supported */
#define MAX_MFC 5

#undef DEBUG

static struct parport *this_port[MAX_MFC] = {NULL, };
static volatile int dummy; /* for trigger readds */

#define pia(dev) ((struct pia *)(dev->base))
static struct parport_operations pp_mfc3_ops;

static void mfc3_write_data(struct parport *p, unsigned char data)
{
        pr_debug("write_data %c\n", data);

        dummy = pia(p)->pprb; /* clears irq bit */
        /* Triggers also /STROBE.*/
        pia(p)->pprb = data;
}

static unsigned char mfc3_read_data(struct parport *p)
{
        /* clears interrupt bit. Triggers also /STROBE. */
        return pia(p)->pprb;
}

static unsigned char control_pc_to_mfc3(unsigned char control)
{
        unsigned char ret = 32|64;

        if (control & PARPORT_CONTROL_SELECT) /* XXX: What is SELECP? */
                ret &= ~32; /* /SELECT_IN */
        if (control & PARPORT_CONTROL_INIT) /* INITP */
                ret |= 128;
        if (control & PARPORT_CONTROL_AUTOFD) /* AUTOLF */
                ret &= ~64;
        /* PARPORT_CONTROL_STROBE handled directly by hardware */
        return ret;
}

static unsigned char control_mfc3_to_pc(unsigned char control)
{
        unsigned char ret = PARPORT_CONTROL_STROBE 
                          | PARPORT_CONTROL_AUTOFD | PARPORT_CONTROL_SELECT;

        if (control & 128) /* /INITP */
                ret |= PARPORT_CONTROL_INIT;
        if (control & 64) /* /AUTOLF */
                ret &= ~PARPORT_CONTROL_AUTOFD;
        if (control & 32) /* /SELECT_IN */
                ret &= ~PARPORT_CONTROL_SELECT;
        return ret;
}

static void mfc3_write_control(struct parport *p, unsigned char control)
{
        pr_debug("write_control %02x\n", control);
        pia(p)->ppra = (pia(p)->ppra & 0x1f) | control_pc_to_mfc3(control);
}
        
static unsigned char mfc3_read_control( struct parport *p)
{
        pr_debug("read_control\n");
        return control_mfc3_to_pc(pia(p)->ppra & 0xe0);
}

static unsigned char mfc3_frob_control( struct parport *p, unsigned char mask, unsigned char val)
{
        unsigned char old;

        pr_debug("frob_control mask %02x, value %02x\n", mask, val);
        old = mfc3_read_control(p);
        mfc3_write_control(p, (old & ~mask) ^ val);
        return old;
}

static unsigned char status_mfc3_to_pc(unsigned char status)
{
        unsigned char ret = PARPORT_STATUS_BUSY;

        if (status & 1) /* Busy */
                ret &= ~PARPORT_STATUS_BUSY;
        if (status & 2) /* PaperOut */
                ret |= PARPORT_STATUS_PAPEROUT;
        if (status & 4) /* Selected */
                ret |= PARPORT_STATUS_SELECT;
        if (status & 8) /* Ack */
                ret |= PARPORT_STATUS_ACK;
        if (status & 16) /* /ERROR */
                ret |= PARPORT_STATUS_ERROR;

        return ret;
}

static unsigned char mfc3_read_status(struct parport *p)
{
        unsigned char status;

        status = status_mfc3_to_pc(pia(p)->ppra & 0x1f);
        pr_debug("read_status %02x\n", status);
        return status;
}

static int use_cnt;

static irqreturn_t mfc3_interrupt(int irq, void *dev_id)
{
        int i;

        for( i = 0; i < MAX_MFC; i++)
                if (this_port[i] != NULL)
                        if (pia(this_port[i])->crb & 128) { /* Board caused interrupt */
                                dummy = pia(this_port[i])->pprb; /* clear irq bit */
                                parport_generic_irq(this_port[i]);
                        }
        return IRQ_HANDLED;
}

static void mfc3_enable_irq(struct parport *p)
{
        pia(p)->crb |= PIA_C1_ENABLE_IRQ;
}

static void mfc3_disable_irq(struct parport *p)
{
        pia(p)->crb &= ~PIA_C1_ENABLE_IRQ;
}

static void mfc3_data_forward(struct parport *p)
{
        pr_debug("forward\n");
        pia(p)->crb &= ~PIA_DDR; /* make data direction register visible */
        pia(p)->pddrb = 255; /* all pins output */
        pia(p)->crb |= PIA_DDR; /* make data register visible - default */
}

static void mfc3_data_reverse(struct parport *p)
{
        pr_debug("reverse\n");
        pia(p)->crb &= ~PIA_DDR; /* make data direction register visible */
        pia(p)->pddrb = 0; /* all pins input */
        pia(p)->crb |= PIA_DDR; /* make data register visible - default */
}

static void mfc3_init_state(struct pardevice *dev, struct parport_state *s)
{
        s->u.amiga.data = 0;
        s->u.amiga.datadir = 255;
        s->u.amiga.status = 0;
        s->u.amiga.statusdir = 0xe0;
}

static void mfc3_save_state(struct parport *p, struct parport_state *s)
{
        s->u.amiga.data = pia(p)->pprb;
        pia(p)->crb &= ~PIA_DDR;
        s->u.amiga.datadir = pia(p)->pddrb;
        pia(p)->crb |= PIA_DDR;
        s->u.amiga.status = pia(p)->ppra;
        pia(p)->cra &= ~PIA_DDR;
        s->u.amiga.statusdir = pia(p)->pddrb;
        pia(p)->cra |= PIA_DDR;
}

static void mfc3_restore_state(struct parport *p, struct parport_state *s)
{
        pia(p)->pprb = s->u.amiga.data;
        pia(p)->crb &= ~PIA_DDR;
        pia(p)->pddrb = s->u.amiga.datadir;
        pia(p)->crb |= PIA_DDR;
        pia(p)->ppra = s->u.amiga.status;
        pia(p)->cra &= ~PIA_DDR;
        pia(p)->pddrb = s->u.amiga.statusdir;
        pia(p)->cra |= PIA_DDR;
}

static struct parport_operations pp_mfc3_ops = {
        .write_data     = mfc3_write_data,
        .read_data      = mfc3_read_data,

        .write_control  = mfc3_write_control,
        .read_control   = mfc3_read_control,
        .frob_control   = mfc3_frob_control,

        .read_status    = mfc3_read_status,

        .enable_irq     = mfc3_enable_irq,
        .disable_irq    = mfc3_disable_irq,

        .data_forward   = mfc3_data_forward, 
        .data_reverse   = mfc3_data_reverse, 

        .init_state     = mfc3_init_state,
        .save_state     = mfc3_save_state,
        .restore_state  = mfc3_restore_state,

        .epp_write_data = parport_ieee1284_epp_write_data,
        .epp_read_data  = parport_ieee1284_epp_read_data,
        .epp_write_addr = parport_ieee1284_epp_write_addr,
        .epp_read_addr  = parport_ieee1284_epp_read_addr,

        .ecp_write_data = parport_ieee1284_ecp_write_data,
        .ecp_read_data  = parport_ieee1284_ecp_read_data,
        .ecp_write_addr = parport_ieee1284_ecp_write_addr,

        .compat_write_data      = parport_ieee1284_write_compat,
        .nibble_read_data       = parport_ieee1284_read_nibble,
        .byte_read_data         = parport_ieee1284_read_byte,

        .owner          = THIS_MODULE,
};

/* ----------- Initialisation code --------------------------------- */

static int __init parport_mfc3_init(void)
{
        struct parport *p;
        int pias = 0;
        struct pia *pp;
        struct zorro_dev *z = NULL;

        if (!MACH_IS_AMIGA)
                return -ENODEV;

        while ((z = zorro_find_device(ZORRO_PROD_BSC_MULTIFACE_III, z))) {
                unsigned long piabase = z->resource.start+PIABASE;
                if (!request_mem_region(piabase, sizeof(struct pia), "PIA"))
                        continue;

                pp = ZTWO_VADDR(piabase);
                pp->crb = 0;
                pp->pddrb = 255; /* all data pins output */
                pp->crb = PIA_DDR|32|8;
                dummy = pp->pddrb; /* reading clears interrupt */
                pp->cra = 0;
                pp->pddra = 0xe0; /* /RESET,  /DIR ,/AUTO-FEED output */
                pp->cra = PIA_DDR;
                pp->ppra = 0; /* reset printer */
                udelay(10);
                pp->ppra = 128;
                p = parport_register_port((unsigned long)pp, IRQ_AMIGA_PORTS,
                                          PARPORT_DMA_NONE, &pp_mfc3_ops);
                if (!p)
                        goto out_port;

                if (p->irq != PARPORT_IRQ_NONE) {
                        if (use_cnt++ == 0)
                                if (request_irq(IRQ_AMIGA_PORTS, mfc3_interrupt, IRQF_SHARED, p->name, &pp_mfc3_ops))
                                        goto out_irq;
                }
                p->dev = &z->dev;

                this_port[pias++] = p;
                pr_info("%s: Multiface III port using irq\n", p->name);
                /* XXX: set operating mode */

                p->private_data = (void *)piabase;
                parport_announce_port (p);

                if (pias >= MAX_MFC)
                        break;
                continue;

        out_irq:
                parport_put_port(p);
        out_port:
                release_mem_region(piabase, sizeof(struct pia));
        }

        return pias ? 0 : -ENODEV;
}

static void __exit parport_mfc3_exit(void)
{
        int i;

        for (i = 0; i < MAX_MFC; i++) {
                if (!this_port[i])
                        continue;
                parport_remove_port(this_port[i]);
                if (this_port[i]->irq != PARPORT_IRQ_NONE) {
                        if (--use_cnt == 0) 
                                free_irq(IRQ_AMIGA_PORTS, &pp_mfc3_ops);
                }
                release_mem_region(ZTWO_PADDR(this_port[i]->private_data), sizeof(struct pia));
                parport_put_port(this_port[i]);
        }
}


MODULE_AUTHOR("Joerg Dorchain <joerg@dorchain.net>");
MODULE_DESCRIPTION("Parport Driver for Multiface 3 expansion cards Parallel Port");
MODULE_LICENSE("GPL");

module_init(parport_mfc3_init)
module_exit(parport_mfc3_exit)