drivers/staging/vme/devices/vme_pio2_cntr.c

/*
 * GE PIO2 Counter Driver
 *
 * Author: Martyn Welch <martyn.welch@ge.com>
 * Copyright 2009 GE Intelligent Platforms Embedded Systems, Inc.
 *
 * This program is free software; you can redistribute  it and/or modify it
 * under  the terms of  the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 *
 * The PIO-2 has 6 counters, currently this code just disables the interrupts
 * and leaves them alone.
 *
 */

#include <linux/device.h>
#include <linux/types.h>
#include <linux/gpio.h>
#include <linux/vme.h>

#include "vme_pio2.h"

static int pio2_cntr_irq_set(struct pio2_card *card, int id)
{
	int retval;
	u8 data;

	data = PIO2_CNTR_SC_DEV[id] | PIO2_CNTR_RW_BOTH | card->cntr[id].mode;
	retval = vme_master_write(card->window, &data, 1, PIO2_CNTR_CTRL[id]);
	if (retval < 0)
		return retval;

	data = card->cntr[id].count & 0xFF;
	retval = vme_master_write(card->window, &data, 1, PIO2_CNTR_DATA[id]);
	if (retval < 0)
		return retval;

	data = (card->cntr[id].count >> 8) & 0xFF;
	retval = vme_master_write(card->window, &data, 1, PIO2_CNTR_DATA[id]);
	if (retval < 0)
		return retval;

	return 0;
}

int pio2_cntr_reset(struct pio2_card *card)
{
	int i, retval = 0;
	u8 reg;

	/* Clear down all timers */
	for (i = 0; i < 6; i++) {
		card->cntr[i].mode = PIO2_CNTR_MODE5;
		card->cntr[i].count = 0;
		retval = pio2_cntr_irq_set(card, i);
		if (retval < 0)
			return retval;
	}

	/* Ensure all counter interrupts are cleared */
	do {
		retval = vme_master_read(card->window, &reg, 1,
					 PIO2_REGS_INT_STAT_CNTR);
		if (retval < 0)
			return retval;
	} while (reg != 0);

	return retval;
}