// 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)