mac_esp.c

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				quick = 0;
			} else {
				/* q950, 900, 700 */
				quick = 1;
				writel(0x1d1, 0xf9800024);
				esp->dregs = (void *) 0xf9800024;
			}

		} else { /* chipnum */

			quick = 1;
			writel(0x1d1, 0xf9800028);
			esp->dregs = (void *) 0xf9800028;

		} /* chipnum == 0 */

		/* use pio for command bytes; pio for message/data: TBI */
		esp->do_pio_cmds = 1;

		/* Set the command buffer */
		esp->esp_command = (volatile unsigned char*) cmd_buffer;
		esp->esp_command_dvma = (volatile unsigned char*) cmd_buffer;

		/* various functions */
		esp->dma_bytes_sent = &dma_bytes_sent;
		esp->dma_can_transfer = &dma_can_transfer;
		esp->dma_dump_state = &dma_dump_state;
		esp->dma_init_read = NULL;
		esp->dma_init_write = NULL;
		esp->dma_ints_off = &dma_ints_off;
		esp->dma_ints_on = &dma_ints_on;

		esp->dma_ports_p = &dma_ports_p;


		/* Optional functions */
		esp->dma_barrier = NULL;
		esp->dma_drain = NULL;
		esp->dma_invalidate = NULL;
		esp->dma_irq_entry = NULL;
		esp->dma_irq_exit = NULL;
		esp->dma_led_on = NULL;
		esp->dma_led_off = NULL;
		esp->dma_poll = NULL;
		esp->dma_reset = NULL;

		/* SCSI chip speed */
		/* below esp->cfreq = 40000000; */


		if (quick) {
			/* 'quick' means there's handshake glue logic like in the 5380 case */
			esp->dma_setup = &dma_setup_quick;
		} else {
			esp->dma_setup = &dma_setup;
		}

		if (chipnum == 0) {

			esp->irq = IRQ_MAC_SCSI;

			request_irq(IRQ_MAC_SCSI, esp_intr, 0, "Mac ESP SCSI", esp);
#if 0	/* conflicts with IOP ADB */
			request_irq(IRQ_MAC_SCSIDRQ, fake_drq, 0, "Mac ESP DRQ", esp);
#endif

			if (macintosh_config->scsi_type == MAC_SCSI_QUADRA) {
				esp->cfreq = 16500000;
			} else {
				esp->cfreq = 25000000;
			}


		} else { /* chipnum == 1 */

			esp->irq = IRQ_MAC_SCSIDRQ;
#if 0	/* conflicts with IOP ADB */
			request_irq(IRQ_MAC_SCSIDRQ, esp_intr, 0, "Mac ESP SCSI 2", esp);
#endif

			esp->cfreq = 25000000;

		}

		if (quick) {
			printk("esp: using quick version\n");
		}

		printk("esp: addr at 0x%p\n", esp->eregs);

		esp->scsi_id = 7;
		esp->diff = 0;

		esp_initialize(esp);

	} /* for chipnum */

	if (chipspresent)
		printk("\nmac_esp: %d esp controllers found\n", chipspresent);

	esp_initialized = chipspresent;

	return chipspresent;
}

/*
 * I've been wondering what this is supposed to do, for some time. Talking 
 * to Allen Briggs: These machines have an extra register someplace where the
 * DRQ pin of the ESP can be monitored. That isn't useful for determining 
 * anything else (such as reselect interrupt or other magic) though. 
 * Maybe make the semantics should be changed like 
 * if (esp->current_SC)
 *	... check DRQ flag ...
 * else 
 *	... disconnected, check pending VIA interrupt ...
 *
 * There's a problem with using the dabf flag or mac_irq_pending() here: both
 * seem to return 1 even though no interrupt is currently pending, resulting
 * in esp_exec_cmd() holding off the next command, and possibly infinite loops
 * in esp_intr(). 
 * Short term fix: just use esp_status & ESP_STAT_INTR here, as long as we
 * use simple PIO. The DRQ status will be important when implementing pseudo
 * DMA mode (set up ESP transfer count, return, do a batch of bytes in PIO or 
 * 'hardware handshake' mode upon DRQ).
 * If you plan on changing this (i.e. to save the esp_status register access in 
 * favor of a VIA register access or a shadow register for the IFR), make sure
 * to try a debug version of this first to monitor what registers would be a good
 * indicator of the ESP interrupt.
 */

static int esp_dafb_dma_irq_p(struct NCR_ESP * esp)
{
	unsigned int ret;
	int sreg = esp_read(esp->eregs->esp_status);

#ifdef DEBUG_MAC_ESP
	printk("mac_esp: esp_dafb_dma_irq_p dafb %d irq %d\n", 
		readl(esp->dregs), mac_irq_pending(IRQ_MAC_SCSI));
#endif

	sreg &= ESP_STAT_INTR;

	/*
	 * maybe working; this is essentially what's used for iosb_dma_irq_p
	 */
	if (sreg)
		return 1;
	else
		return 0;

	/*
	 * didn't work ...
	 */
#if 0
	if (esp->current_SC)
		ret = readl(esp->dregs) & 0x200;
	else if (esp->disconnected_SC)
		ret = 1; /* sreg ?? */
	else
		ret = mac_irq_pending(IRQ_MAC_SCSI);

	return(ret);
#endif

}

/*
 * See above: testing mac_irq_pending always returned 8 (SCSI IRQ) regardless 
 * of the actual ESP status.
 */

static int esp_iosb_dma_irq_p(struct NCR_ESP * esp)
{
	int ret  = mac_irq_pending(IRQ_MAC_SCSI) || mac_irq_pending(IRQ_MAC_SCSIDRQ);
	int sreg = esp_read(esp->eregs->esp_status);

#ifdef DEBUG_MAC_ESP
	printk("mac_esp: dma_irq_p drq %d irq %d sreg %x curr %p disc %p\n", 
		mac_irq_pending(IRQ_MAC_SCSIDRQ), mac_irq_pending(IRQ_MAC_SCSI), 
		sreg, esp->current_SC, esp->disconnected_SC);
#endif

	sreg &= ESP_STAT_INTR;

	if (sreg)
		return (sreg);
	else
		return 0;
}

/*
 * This seems to be OK for PIO at least ... usually 0 after PIO.
 */

static int dma_bytes_sent(struct NCR_ESP * esp, int fifo_count)
{

#ifdef DEBUG_MAC_ESP
	printk("mac_esp: dma bytes sent = %x\n", fifo_count);
#endif

	return fifo_count;
}

/*
 * dma_can_transfer is used to switch between DMA and PIO, if DMA (pseudo)
 * is ever implemented. Returning 0 here will use PIO.
 */

static int dma_can_transfer(struct NCR_ESP * esp, Scsi_Cmnd * sp)
{
	unsigned long sz = sp->SCp.this_residual;
#if 0	/* no DMA yet; make conditional */
	if (sz > 0x10000000) {
		sz = 0x10000000;
	}
	printk("mac_esp: dma can transfer = 0lx%x\n", sz);
#else

#ifdef DEBUG_MAC_ESP
	printk("mac_esp: pio to transfer = %ld\n", sz);
#endif

	sz = 0;
#endif
	return sz;
}

/*
 * Not yet ...
 */

static void dma_dump_state(struct NCR_ESP * esp)
{
#ifdef DEBUG_MAC_ESP
	printk("mac_esp: dma_dump_state: called\n");
#endif
#if 0
	ESPLOG(("esp%d: dma -- cond_reg<%02x>\n",
		esp->esp_id, ((struct mac_dma_registers *)
		(esp->dregs))->cond_reg));
#endif
}

/*
 * DMA setup: should be used to set up the ESP transfer count for pseudo
 * DMA transfers; need a DRQ transfer function to do the actual transfer
 */

static void dma_init_read(struct NCR_ESP * esp, char * vaddress, int length)
{
	printk("mac_esp: dma_init_read\n");
}


static void dma_init_write(struct NCR_ESP * esp, char * vaddress, int length)
{
	printk("mac_esp: dma_init_write\n");
}


static void dma_ints_off(struct NCR_ESP * esp)
{
	mac_turnoff_irq(esp->irq);
}


static void dma_ints_on(struct NCR_ESP * esp)
{
	mac_turnon_irq(esp->irq);
}

/*
 * generic dma_irq_p(), unused
 */

static int dma_irq_p(struct NCR_ESP * esp)
{
	int i = esp_read(esp->eregs->esp_status);

#ifdef DEBUG_MAC_ESP
	printk("mac_esp: dma_irq_p status %d\n", i);
#endif

	return (i & ESP_STAT_INTR);
}

static int dma_irq_p_quick(struct NCR_ESP * esp)
{
	/*
	 * Copied from iosb_dma_irq_p()
	 */
	int ret  = mac_irq_pending(IRQ_MAC_SCSI) || mac_irq_pending(IRQ_MAC_SCSIDRQ);
	int sreg = esp_read(esp->eregs->esp_status);

#ifdef DEBUG_MAC_ESP
	printk("mac_esp: dma_irq_p drq %d irq %d sreg %x curr %p disc %p\n", 
		mac_irq_pending(IRQ_MAC_SCSIDRQ), mac_irq_pending(IRQ_MAC_SCSI), 
		sreg, esp->current_SC, esp->disconnected_SC);
#endif

	sreg &= ESP_STAT_INTR;

	if (sreg)
		return (sreg);
	else
		return 0;

}

static void dma_led_off(struct NCR_ESP * esp)
{
#ifdef DEBUG_MAC_ESP
	printk("mac_esp: dma_led_off: called\n");
#endif
}


static void dma_led_on(struct NCR_ESP * esp)
{
#ifdef DEBUG_MAC_ESP
	printk("mac_esp: dma_led_on: called\n");
#endif
}


static int dma_ports_p(struct NCR_ESP * esp)
{
	return 0;
}


static void dma_setup(struct NCR_ESP * esp, __u32 addr, int count, int write)
{

#ifdef DEBUG_MAC_ESP
	printk("mac_esp: dma_setup\n");
#endif

	if (write) {
		dma_init_read(esp, (char *) addr, count);
	} else {
		dma_init_write(esp, (char *) addr, count);
	}
}


static void dma_setup_quick(struct NCR_ESP * esp, __u32 addr, int count, int write)
{
#ifdef DEBUG_MAC_ESP
	printk("mac_esp: dma_setup_quick\n");
#endif
}

static Scsi_Host_Template driver_template = SCSI_MAC_ESP;

#include "scsi_module.c"