/* dvma.c:  Routines that are used to access DMA on the Sparc SBus.
 *
 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
 */

#include <linux/kernel.h>
#include <linux/malloc.h>

#include <asm/oplib.h>
#include <asm/contregs.h>
#include <asm/sysen.h>
#include <asm/delay.h>
#include <asm/idprom.h>
#include <asm/machines.h>
#include <asm/io.h>
#include <asm/dma.h>
#include <asm/sbus.h>
#include <asm/vac-ops.h>
#include <asm/vaddrs.h>

struct Linux_SBus_DMA *dma_chain;

/* Print out the current values in the DMA control registers */
void
dump_dma_regs(struct sparc_dma_registers *dregs)
{
	printk("DMA CONTROL<%08lx>  ADDR<%08lx> CNT<%08lx> TEST<%08lx>\n",
	       dregs->cond_reg,
	       (unsigned long) dregs->st_addr,
	       (unsigned long) dregs->cnt,
	       (unsigned long) dregs->dma_test);
	return;
}


/* Probe this SBus DMA module(s) */
unsigned long
dvma_init(struct linux_sbus *sbus, unsigned long memory_start)
{
	struct linux_sbus_device *this_dev;
	struct Linux_SBus_DMA *dma;
	struct Linux_SBus_DMA *dchain;
	static int num_dma=0;

	for_each_sbusdev(this_dev, sbus) {
		if(strcmp(this_dev->prom_name, "dma") &&
		   strcmp(this_dev->prom_name, "ledma") &&
		   strcmp(this_dev->prom_name, "espdma"))
			continue;

		/* Found one... */
		dma = (struct Linux_SBus_DMA *) memory_start;
		memory_start += sizeof(struct Linux_SBus_DMA);

		dma->SBus_dev = this_dev;

		/* Put at end of dma chain */
		dchain = dma_chain;
		if(dchain) {
			while(dchain->next) dchain=dchain->next;
			dchain->next=dma;
		} else {
			/* We're the first in line */
			dma_chain=dma;
		}
		dma->next = 0;

		printk("dma%d: ", num_dma);
		num_dma++;

		/* The constant PAGE_SIZE that is passed to sparc_alloc_io makes the
		 * routine only alloc 1 page, that was what the original code did
		 */
		prom_apply_sbus_ranges(dma->SBus_dev->reg_addrs, 0x1);
		dma->regs = (struct sparc_dma_registers *)
			sparc_alloc_io (dma->SBus_dev->reg_addrs[0].phys_addr, 0,
					PAGE_SIZE, "dma",
					dma->SBus_dev->reg_addrs[0].which_io, 0x0);

		dma->node = dma->SBus_dev->prom_node;
		dma->running=0;      /* No transfers going on as of yet */
		dma->allocated=0;    /* No one has allocated us yet */
		switch((dma->regs->cond_reg)&DMA_DEVICE_ID) {
		case DMA_VERS0:
			dma->revision=dvmarev0;
			printk("Revision 0 ");
			break;
		case DMA_ESCV1:
			dma->revision=dvmaesc1;
			printk("ESC Revision 1 ");
			break;
		case DMA_VERS1:
			dma->revision=dvmarev1;
			printk("Revision 1 ");
			break;
		case DMA_VERS2:
			dma->revision=dvmarev2;
			printk("Revision 2 ");
			break;
		case DMA_VERSPLUS:
			dma->revision=dvmarevplus;
			printk("Revision 1 PLUS ");
			break;
		default:
			printk("unknown dma version");
			dma->allocated = 1;
			break;
		}
		printk("\n");
#if 0 /* Clutters up the screen */
		dump_dma_regs(dma->regs);
#endif
	};  /* while(this_dev) */

	return memory_start;
}