parport_amiga.c

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/* Low-level parallel port routines for the Amiga built-in port
 *
 * Author: Joerg Dorchain <[email protected]>
 *
 * This is a complete rewrite of the code, but based heaviy upon the old
 * lp_intern. code.
 *
 * The built-in Amiga parallel port provides one port at a fixed address
 * with 8 bidirectional data lines (D0 - D7) and 3 bidirectional status
 * lines (BUSY, POUT, SEL), 1 output control line /STROBE (raised automatically
 * in hardware when the data register is accessed), and 1 input control line
 * /ACK, able to cause an interrupt, but both not directly settable by
 * software.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/parport.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>

#include <asm/setup.h>
#include <asm/amigahw.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/amigaints.h>

#undef DEBUG
#ifdef DEBUG
#define DPRINTK printk
#else
#define DPRINTK(x...)   do { } while (0)
#endif


static void amiga_write_data(struct parport *p, unsigned char data)
{
    DPRINTK(KERN_DEBUG "write_data %c\n",data);
    /* Triggers also /STROBE. This behavior cannot be changed */
    ciaa.prb = data;
    mb();
}

static unsigned char amiga_read_data(struct parport *p)
{
    /* Triggers also /STROBE. This behavior cannot be changed */
    return ciaa.prb;
}

static unsigned char control_amiga_to_pc(unsigned char control)
{
    return PARPORT_CONTROL_SELECT |
          PARPORT_CONTROL_AUTOFD | PARPORT_CONTROL_STROBE;
    /* fake value: interrupt enable, select in, no reset,
    no autolf, no strobe - seems to be closest the wiring diagram */
}

static void amiga_write_control(struct parport *p, unsigned char control)
{
    DPRINTK(KERN_DEBUG "write_control %02x\n",control);
    /* No implementation possible */
}
    
static unsigned char amiga_read_control( struct parport *p)
{
    DPRINTK(KERN_DEBUG "read_control \n");
    return control_amiga_to_pc(0);
}

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

    DPRINTK(KERN_DEBUG "frob_control mask %02x, value %02x\n",mask,val);
    old = amiga_read_control(p);
    amiga_write_control(p, (old & ~mask) ^ val);
    return old;
}

static unsigned char status_amiga_to_pc(unsigned char status)
{
    unsigned char ret = PARPORT_STATUS_BUSY | PARPORT_STATUS_ACK | PARPORT_STATUS_ERROR;

    if (status & 1) /* Busy */
        ret &= ~PARPORT_STATUS_BUSY;
    if (status & 2) /* PaperOut */
        ret |= PARPORT_STATUS_PAPEROUT;
    if (status & 4) /* Selected */
        ret |= PARPORT_STATUS_SELECT;
    /* the rest is not connected or handled autonomously in hardware */

    return ret;
}

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

    status = status_amiga_to_pc(ciab.pra & 7);
    DPRINTK(KERN_DEBUG "read_status %02x\n", status);
    return status;
}

static void amiga_enable_irq(struct parport *p)
{
    enable_irq(IRQ_AMIGA_CIAA_FLG);
}

static void amiga_disable_irq(struct parport *p)
{
    disable_irq(IRQ_AMIGA_CIAA_FLG);
}

static void amiga_data_forward(struct parport *p)
{
    DPRINTK(KERN_DEBUG "forward\n");
    ciaa.ddrb = 0xff; /* all pins output */
    mb();
}

static void amiga_data_reverse(struct parport *p)
{
    DPRINTK(KERN_DEBUG "reverse\n");
    ciaa.ddrb = 0; /* all pins input */
    mb();
}

static void amiga_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 = 0;
}

static void amiga_save_state(struct parport *p, struct parport_state *s)
{
    mb();
    s->u.amiga.data = ciaa.prb;
    s->u.amiga.datadir = ciaa.ddrb;
    s->u.amiga.status = ciab.pra & 7;
    s->u.amiga.statusdir = ciab.ddra & 7;
    mb();
}

static void amiga_restore_state(struct parport *p, struct parport_state *s)
{
    mb();
    ciaa.prb = s->u.amiga.data;
    ciaa.ddrb = s->u.amiga.datadir;
    ciab.pra |= (ciab.pra & 0xf8) | s->u.amiga.status;
    ciab.ddra |= (ciab.ddra & 0xf8) | s->u.amiga.statusdir;
    mb();
}

static struct parport_operations pp_amiga_ops = {
    .write_data = amiga_write_data,
    .read_data  = amiga_read_data,

    .write_control  = amiga_write_control,
    .read_control   = amiga_read_control,
    .frob_control   = amiga_frob_control,

    .read_status    = amiga_read_status,

    .enable_irq = amiga_enable_irq,
    .disable_irq    = amiga_disable_irq,

    .data_forward   = amiga_data_forward,
    .data_reverse   = amiga_data_reverse,

    .init_state = amiga_init_state,
    .save_state = amiga_save_state,
    .restore_state  = amiga_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 amiga_parallel_probe(struct platform_device *pdev)
{
    struct parport *p;
    int err;

    ciaa.ddrb = 0xff;
    ciab.ddra &= 0xf8;
    mb();

    p = parport_register_port((unsigned long)&ciaa.prb, IRQ_AMIGA_CIAA_FLG,
                   PARPORT_DMA_NONE, &pp_amiga_ops);
    if (!p)
        return -EBUSY;

    err = request_irq(IRQ_AMIGA_CIAA_FLG, parport_irq_handler, 0, p->name,
              p);
    if (err)
        goto out_irq;

    printk(KERN_INFO "%s: Amiga built-in port using irq\n", p->name);
    /* XXX: set operating mode */
    parport_announce_port(p);

    platform_set_drvdata(pdev, p);

    return 0;

out_irq:
    parport_put_port(p);
    return err;
}

static int __exit amiga_parallel_remove(struct platform_device *pdev)
{
    struct parport *port = platform_get_drvdata(pdev);

    parport_remove_port(port);
    if (port->irq != PARPORT_IRQ_NONE)
        free_irq(IRQ_AMIGA_CIAA_FLG, port);
    parport_put_port(port);
    platform_set_drvdata(pdev, NULL);
    return 0;
}

static struct platform_driver amiga_parallel_driver = {
    .remove = __exit_p(amiga_parallel_remove),
    .driver   = {
        .name   = "amiga-parallel",
        .owner  = THIS_MODULE,
    },
};

static int __init amiga_parallel_init(void)
{
    return platform_driver_probe(&amiga_parallel_driver,
                     amiga_parallel_probe);
}

module_init(amiga_parallel_init);

static void __exit amiga_parallel_exit(void)
{
    platform_driver_unregister(&amiga_parallel_driver);
}

module_exit(amiga_parallel_exit);

MODULE_AUTHOR("Joerg Dorchain <[email protected]>");
MODULE_DESCRIPTION("Parport Driver for Amiga builtin Port");
MODULE_SUPPORTED_DEVICE("Amiga builtin Parallel Port");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:amiga-parallel");