/*
 * abcio.c
 *
 * Handle ABC-bus I/O operations
 */

#include "fw.h"
#include "io.h"
#include "irq.h"
#include "abcio.h"

static struct abc_dev *abc_device[64];
static struct abc_dev *selected_dev;
static uint8_t abc_devsel = -1;

/* Not inlining this makes the code larger...! */
static inline __attribute__((always_inline))
void abc_select(struct abc_dev *dev)
{
    selected_dev = dev;
    if (!dev) {
	ABC_BUSY_MASK = 0x0082;	/* Only RST# and CS# */
	ABC_INP = 0;
    } else {
	ABC_BUSY_MASK = dev->callback_mask | 0x0082;
	ABC_INP = dev->inp_data_w;
    }
}

IRQHANDLER(abc)
{
    unsigned int what = ABC_BUSY_STATUS;
    unsigned int callback =
	selected_dev ? (what & selected_dev->callback_mask) : 0;
    struct abc_dev *dev = selected_dev;

    if (what & 0xff) {
	unsigned int addr = ABC_OUT_ADDR;
	unsigned int data = ABC_OUT_DATA;

	switch (addr) {
	case 0:
	    dev->out_data[addr] = data;
	    if (dev->out_cnt--) {
		*dev->out_buf++ = data;
		dev->inp_data[1] &= dev->status_first_out_mask;
		ABC_INP1_DATA = dev->inp_data[1];
		if (!dev->out_cnt)
		    break;	/* No callback */
	    }
	    if (callback & 1)
		dev->callback_out(dev, data);
	    break;

	case 2 ... 5:
	    dev->out_data[addr] = data;
	    if (callback & (1 << addr))
		dev->callback_cmd(dev, data, addr);
	    break;

	case 1:
	    dev = abc_device[abc_devsel = data & 0x3f];
	    abc_select(dev);

	    if (dev)
		dev->out_data[addr] = data;
	    break;

	case 7:
	    /* XXX: broadcast reset to devices? */
	    abc_devsel = -1;
	    abc_select(NULL);
	    break;

	default:
	    break;
	}
    }

    if (what & 0x100) {
	if (--dev->inp_cnt) {
	    dev->inp_data[1] &= dev->status_first_inp_mask;
	    ABC_INP1_DATA = dev->inp_data[1];
	    ABC_INP0_DATA = dev->inp_data[0] = *dev->inp_buf++;
	} else {
	    ABC_INP0_DATA = dev->inp_data[0] = dev->inp_data_def;
	    if (callback & 0x100)
		dev->callback_inp(dev);
	}
    }

    if (what & 0x200) {
	ABC_INP1_DATA = dev->inp_data[1];
	if (callback & 0x200)
	    dev->callback_status(dev);
    }

    ABC_BUSY_STATUS = what;
}

void abc_setup_out_queue(struct abc_dev *dev, void *buf, size_t len,
			 uint8_t status)
{
    mask_irq(ABC_IRQ);

    dev->out_buf = buf;
    dev->out_cnt = len;
    ABC_INP1_DATA = dev->inp_data[1] = status;
    dev->callback_mask |= (1 << 0);

    unmask_irq(ABC_IRQ);
}

void abc_setup_inp_queue(struct abc_dev *dev, const void *buf, size_t len,
			 uint8_t status)
{
    mask_irq(ABC_IRQ);

    dev->inp_buf = buf;
    dev->inp_cnt = len;
    ABC_INP0_DATA = dev->inp_data[0] = *dev->inp_buf++;
    ABC_INP1_DATA = dev->inp_data[1] = status;
    dev->callback_mask |= (1 << 8);

    unmask_irq(ABC_IRQ);
}

void abc_set_inp_default(struct abc_dev *dev, uint8_t val)
{
    mask_irq(ABC_IRQ);

    dev->inp_data_def = val;
    if (!dev->inp_cnt) {
	dev->inp_data[0] = val;
	if (dev == selected_dev)
	    ABC_INP0_DATA = val;
    }

    unmask_irq(ABC_IRQ);
}

void abc_set_inp_status(struct abc_dev *dev, uint8_t val)
{
    mask_irq(ABC_IRQ);

    dev->inp_data[1] = val;
    if (dev == selected_dev)
	ABC_INP1_DATA = val;

    unmask_irq(ABC_IRQ);
}

void abc_register(struct abc_dev *dev, unsigned int devsel)
{
    if (devsel > 63)
	return;

    mask_irq(ABC_IRQ);

    abc_device[devsel] = dev;
    if (devsel == abc_devsel)
	abc_select(dev);

    unmask_irq(ABC_IRQ);
}

void abc_init(void)
{
    unsigned int devsel;

    mask_irq(ABC_IRQ);

    devsel = ABC_IOSEL;
    abc_devsel = (devsel & 0x100) ? -1U : devsel & 0x3f;
    abc_select(NULL);

    unmask_irq(ABC_IRQ);
}