intr.c

QNX ADS BSP code for i.MX27 chips

/*
 * $QNXLicenseC: 
 * Copyright 2007, QNX Software Systems.  
 *  
 * Licensed under the Apache License, Version 2.0 (the "License"). You  
 * may not reproduce, modify or distribute this software except in  
 * compliance with the License. You may obtain a copy of the License  
 * at: http://www.apache.org/licenses/LICENSE-2.0  
 *  
 * Unless required by applicable law or agreed to in writing, software  
 * distributed under the License is distributed on an "AS IS" basis,  
 * WITHOUT WARRANTIES OF ANY KIND, either express or implied. 
 * 
 * This file may contain contributions from others, either as  
 * contributors under the License or as licensors under other terms.   
 * Please review this entire file for other proprietary rights or license  
 * notices, as well as the QNX Development Suite License Guide at  
 * http://licensing.qnx.com/license-guide/ for other information. 
 * $
 */


#include "mxcspi.h"



/*
 * We use the same buffer for transmit and receive
 * For exchange, that's exactly what we wanted
 * For Read, it doesn't matter what we write to SPI, so we are OK.
 * For transmit, the receive data is put at the buffer we just transmitted, we are still OK.
 */
static const struct sigevent *spi_intr(void *area, int id)
{
	mx21_cspi_t	*dev = area;
	uintptr_t	base = dev->vbase;
	uint32_t	data;

	do {
		data = in32(base + MX21_CSPI_RXDATA);

		if (dev->rlen <= dev->xlen) {
			switch (dev->dlen) {
			case 1:
				dev->pbuf[dev->rlen++] = data;

				/*
				 * More to transmit?
				 */
				if (dev->tlen < dev->xlen)
					out32(base + MX21_CSPI_TXDATA, dev->pbuf[dev->tlen++]);
				break;
			case 2:
				*(uint16_t *)(&dev->pbuf[dev->rlen]) = data;
				dev->rlen += 2;

				/*
				 * More to transmit?
				 */
				if (dev->tlen < dev->xlen) {
					out32(base + MX21_CSPI_TXDATA, *(uint16_t *)(&dev->pbuf[dev->tlen]));
					dev->tlen += 2;
				}
				break;
			case 3:
			case 4:
				*(uint32_t *)(&dev->pbuf[dev->rlen]) = data;
				dev->rlen += 4;

				/*
				 * More to transmit?
				 */
				if (dev->tlen < dev->xlen) {
					out32(base + MX21_CSPI_TXDATA, *(uint32_t *)(&dev->pbuf[dev->tlen]));
					dev->tlen += 4;
				}
				break;
			}
		}

		if (dev->rlen == dev->xlen) {
			out32(base + MX21_CSPI_INTREG, 0);	/* Disable interrupt */
			return (&dev->spievent);
		}

	} while (in32(base + MX21_CSPI_INTREG) & (1 << 4));

	if ((dev->tlen - dev->rlen) < 4)
		out32(base + MX21_CSPI_INTREG, 1 << 12);	/* Enable RxFIFO data ready interrupt */

	return 0;
}

int mx21_attach_intr(mx21_cspi_t *mx21)
{
	if ((mx21->chid = ChannelCreate(_NTO_CHF_DISCONNECT | _NTO_CHF_UNBLOCK)) == -1)
		return -1;

	if ((mx21->coid = ConnectAttach(0, 0, mx21->chid, _NTO_SIDE_CHANNEL, 0)) == -1) 
		goto fail0;

	mx21->spievent.sigev_notify   = SIGEV_PULSE;
	mx21->spievent.sigev_coid     = mx21->coid;
	mx21->spievent.sigev_code     = MX21_CSPI_EVENT;
	mx21->spievent.sigev_priority = MX21_CSPI_PRIORITY;

	/*
	 * Attach SPI interrupt
	 */
	mx21->iid = InterruptAttach(mx21->irq, spi_intr, mx21, 0, _NTO_INTR_FLAGS_TRK_MSK);

	if (mx21->iid != -1)
		return 0;

	ConnectDetach(mx21->coid);
fail0:
	ChannelDestroy(mx21->chid);

	return -1;
}