/* *  linux/arch/arm/mach-rpc/dma.c * *  Copyright (C) 1998 Russell King * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * *  DMA functions specific to RiscPC architecture */#include <linux/slab.h>#include <linux/mman.h>#include <linux/init.h>#include <linux/interrupt.h>#include <linux/pci.h>#include <asm/page.h>#include <asm/dma.h>#include <asm/fiq.h>#include <asm/io.h>#include <asm/irq.h>#include <asm/hardware.h>#include <asm/uaccess.h>#include <asm/mach/dma.h>#include <asm/hardware/iomd.h>#if 0typedef enum {	dma_size_8	= 1,	dma_size_16	= 2,	dma_size_32	= 4,	dma_size_128	= 16} dma_size_t;#endif#define TRANSFER_SIZE	2#define CURA	(0)#define ENDA	(IOMD_IO0ENDA - IOMD_IO0CURA)#define CURB	(IOMD_IO0CURB - IOMD_IO0CURA)#define ENDB	(IOMD_IO0ENDB - IOMD_IO0CURA)#define CR	(IOMD_IO0CR - IOMD_IO0CURA)#define ST	(IOMD_IO0ST - IOMD_IO0CURA)static void iomd_get_next_sg(struct scatterlist *sg, dma_t *dma){	unsigned long end, offset, flags = 0;	if (dma->sg) {		sg->dma_address = dma->sg->dma_address;		offset = sg->dma_address & ~PAGE_MASK;		end = offset + dma->sg->length;		if (end > PAGE_SIZE)			end = PAGE_SIZE;		if (offset + TRANSFER_SIZE >= end)			flags |= DMA_END_L;		sg->length = end - TRANSFER_SIZE;		dma->sg->length -= end - offset;		dma->sg->dma_address += end - offset;		if (dma->sg->length == 0) {			if (dma->sgcount > 1) {				dma->sg++;				dma->sgcount--;			} else {				dma->sg = NULL;				flags |= DMA_END_S;			}		}	} else {		flags = DMA_END_S | DMA_END_L;		sg->dma_address = 0;		sg->length = 0;	}	sg->length |= flags;}static irqreturn_t iomd_dma_handle(int irq, void *dev_id, struct pt_regs *regs){	dma_t *dma = (dma_t *)dev_id;	unsigned long base = dma->dma_base;	do {		unsigned int status;		status = iomd_readb(base + ST);		if (!(status & DMA_ST_INT))			return IRQ_HANDLED;		if ((dma->state ^ status) & DMA_ST_AB)			iomd_get_next_sg(&dma->cur_sg, dma);		switch (status & (DMA_ST_OFL | DMA_ST_AB)) {		case DMA_ST_OFL:			/* OIA */		case DMA_ST_AB:				/* .IB */			iomd_writel(dma->cur_sg.dma_address, base + CURA);			iomd_writel(dma->cur_sg.length, base + ENDA);			dma->state = DMA_ST_AB;			break;		case DMA_ST_OFL | DMA_ST_AB:		/* OIB */		case 0:					/* .IA */			iomd_writel(dma->cur_sg.dma_address, base + CURB);			iomd_writel(dma->cur_sg.length, base + ENDB);			dma->state = 0;			break;		}		if (status & DMA_ST_OFL &&		    dma->cur_sg.length == (DMA_END_S|DMA_END_L))			break;	} while (1);	dma->state = ~DMA_ST_AB;	disable_irq(irq);	return IRQ_HANDLED;}static int iomd_request_dma(dmach_t channel, dma_t *dma){	return request_irq(dma->dma_irq, iomd_dma_handle,			   SA_INTERRUPT, dma->device_id, dma);}static void iomd_free_dma(dmach_t channel, dma_t *dma){	free_irq(dma->dma_irq, dma);}static void iomd_enable_dma(dmach_t channel, dma_t *dma){	unsigned long dma_base = dma->dma_base;	unsigned int ctrl = TRANSFER_SIZE | DMA_CR_E;	if (dma->invalid) {		dma->invalid = 0;		/*		 * Cope with ISA-style drivers which expect cache		 * coherence.		 */		if (!dma->using_sg) {			dma->buf.dma_address = pci_map_single(NULL,				dma->buf.__address, dma->buf.length,				dma->dma_mode == DMA_MODE_READ ?				PCI_DMA_FROMDEVICE : PCI_DMA_TODEVICE);		}		iomd_writeb(DMA_CR_C, dma_base + CR);		dma->state = DMA_ST_AB;	}			if (dma->dma_mode == DMA_MODE_READ)		ctrl |= DMA_CR_D;	iomd_writeb(ctrl, dma_base + CR);	enable_irq(dma->dma_irq);}static void iomd_disable_dma(dmach_t channel, dma_t *dma){	unsigned long dma_base = dma->dma_base;	unsigned long flags;	local_irq_save(flags);	if (dma->state != ~DMA_ST_AB)		disable_irq(dma->dma_irq);	iomd_writeb(0, dma_base + CR);	local_irq_restore(flags);}static int iomd_set_dma_speed(dmach_t channel, dma_t *dma, int cycle){	int tcr, speed;	if (cycle < 188)		speed = 3;	else if (cycle <= 250)		speed = 2;	else if (cycle < 438)		speed = 1;	else		speed = 0;	tcr = iomd_readb(IOMD_DMATCR);	speed &= 3;	switch (channel) {	case DMA_0:		tcr = (tcr & ~0x03) | speed;		break;	case DMA_1:		tcr = (tcr & ~0x0c) | (speed << 2);		break;	case DMA_2:		tcr = (tcr & ~0x30) | (speed << 4);		break;	case DMA_3:		tcr = (tcr & ~0xc0) | (speed << 6);		break;	default:		break;	}	iomd_writeb(tcr, IOMD_DMATCR);	return speed;}static struct dma_ops iomd_dma_ops = {	.type		= "IOMD",	.request	= iomd_request_dma,	.free		= iomd_free_dma,	.enable		= iomd_enable_dma,	.disable	= iomd_disable_dma,	.setspeed	= iomd_set_dma_speed,};static struct fiq_handler fh = {	.name	= "floppydma"};static void floppy_enable_dma(dmach_t channel, dma_t *dma){	void *fiqhandler_start;	unsigned int fiqhandler_length;	struct pt_regs regs;	if (dma->using_sg)		BUG();	if (dma->dma_mode == DMA_MODE_READ) {		extern unsigned char floppy_fiqin_start, floppy_fiqin_end;		fiqhandler_start = &floppy_fiqin_start;		fiqhandler_length = &floppy_fiqin_end - &floppy_fiqin_start;	} else {		extern unsigned char floppy_fiqout_start, floppy_fiqout_end;		fiqhandler_start = &floppy_fiqout_start;		fiqhandler_length = &floppy_fiqout_end - &floppy_fiqout_start;	}	regs.ARM_r9  = dma->buf.length;	regs.ARM_r10 = (unsigned long)dma->buf.__address;	regs.ARM_fp  = (unsigned long)FLOPPYDMA_BASE;	if (claim_fiq(&fh)) {		printk("floppydma: couldn't claim FIQ.\n");		return;	}	set_fiq_handler(fiqhandler_start, fiqhandler_length);	set_fiq_regs(&regs);	enable_fiq(dma->dma_irq);}static void floppy_disable_dma(dmach_t channel, dma_t *dma){	disable_fiq(dma->dma_irq);	release_fiq(&fh);}static int floppy_get_residue(dmach_t channel, dma_t *dma){	struct pt_regs regs;	get_fiq_regs(&regs);	return regs.ARM_r9;}static struct dma_ops floppy_dma_ops = {	.type		= "FIQDMA",	.enable		= floppy_enable_dma,	.disable	= floppy_disable_dma,	.residue	= floppy_get_residue,};/* * This is virtual DMA - we don't need anything here. */static void sound_enable_disable_dma(dmach_t channel, dma_t *dma){}static struct dma_ops sound_dma_ops = {	.type		= "VIRTUAL",	.enable		= sound_enable_disable_dma,	.disable	= sound_enable_disable_dma,};void __init arch_dma_init(dma_t *dma){	iomd_writeb(0, IOMD_IO0CR);	iomd_writeb(0, IOMD_IO1CR);	iomd_writeb(0, IOMD_IO2CR);	iomd_writeb(0, IOMD_IO3CR);	iomd_writeb(0xa0, IOMD_DMATCR);	dma[DMA_0].dma_base		= IOMD_IO0CURA;	dma[DMA_0].dma_irq		= IRQ_DMA0;	dma[DMA_0].d_ops		= &iomd_dma_ops;	dma[DMA_1].dma_base		= IOMD_IO1CURA;	dma[DMA_1].dma_irq		= IRQ_DMA1;	dma[DMA_1].d_ops		= &iomd_dma_ops;	dma[DMA_2].dma_base		= IOMD_IO2CURA;	dma[DMA_2].dma_irq		= IRQ_DMA2;	dma[DMA_2].d_ops		= &iomd_dma_ops;	dma[DMA_3].dma_base		= IOMD_IO3CURA;	dma[DMA_3].dma_irq		= IRQ_DMA3;	dma[DMA_3].d_ops		= &iomd_dma_ops;	dma[DMA_S0].dma_base		= IOMD_SD0CURA;	dma[DMA_S0].dma_irq		= IRQ_DMAS0;	dma[DMA_S0].d_ops		= &iomd_dma_ops;	dma[DMA_S1].dma_base		= IOMD_SD1CURA;	dma[DMA_S1].dma_irq		= IRQ_DMAS1;	dma[DMA_S1].d_ops		= &iomd_dma_ops;	dma[DMA_VIRTUAL_FLOPPY].dma_irq	= FIQ_FLOPPYDATA;	dma[DMA_VIRTUAL_FLOPPY].d_ops	= &floppy_dma_ops;	dma[DMA_VIRTUAL_SOUND].d_ops	= &sound_dma_ops;	/*	 * Setup DMA channels 2,3 to be for podules	 * and channels 0,1 for internal devices	 */	iomd_writeb(DMA_EXT_IO3|DMA_EXT_IO2, IOMD_DMAEXT);}