max80_fw/fw/abcio.c

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

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

struct abc_dev *abc_device[64];
static struct abc_dev *selected_dev;

static inline void abc_select(struct abc_dev *dev)
{
    selected_dev = dev;
    if (!dev) {
	ABC_BUSY_MASK = 0x0082;	/* Only RST# and CS# */
	ABC_INP_ENABLE = 0;
    } else {
	ABC_BUSY_MASK = dev->callback_mask | 0x0082;
	ABC_INP_ENABLE = 3;
    }
}

IRQHANDLER(abc)
{
    uint16_t what = ABC_BUSY_STATUS;
    bool callback = selected_dev && (what & selected_dev->callback_mask);

    if (what & 0xff) {
	uint8_t addr = ABC_OUT_ADDR;
	uint8_t data = ABC_OUT_DATA;

	switch (addr) {
	case 0:
	    if (selected_dev->out_cnt) {
		*selected_dev->out_buf++ = data;
		selected_dev->inp_data[1] &= selected_dev->status_first_out_mask;
		ABC_INP1_DATA = selected_dev->inp_data[1];
		if (--selected_dev->out_cnt)
		    callback = false;
	    }

	    /* fall through */
	case 2 ... 5:
	    selected_dev->out_data[addr] = data;
	    if (callback)
		selected_dev->callback_out(selected_dev, data, addr);
	    break;

	case 1:
	{
	    struct abc_dev *dev = abc_device[data & 0x3f];
	    abc_select(dev);

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

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

	default:
	    break;
	}
    }

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

    if (what & 0x200) {
	ABC_INP1_DATA = selected_dev->inp_data[1];
	if (callback)
	    selected_dev->callback_inp(selected_dev, 1);
    }

    ABC_BUSY_STATUS = what;
}