arch/arm/mach-rpc/dma.c - linux - Git at Google

 /*
  *  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/dma-mapping.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 0
 typedef 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)
 {
 	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,
 			   IRQF_DISABLED, 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->sg) {
 			dma->sg = &dma->buf;
 			dma->sgcount = 1;
 			dma->buf.length = dma->count;
 			dma->buf.dma_address = dma_map_single(NULL,
 				dma->addr, dma->count,
 				dma->dma_mode == DMA_MODE_READ ?
 				DMA_FROM_DEVICE : DMA_TO_DEVICE);
 		}

 		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->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->count;
 	regs.ARM_r10 = (unsigned long)dma->addr;
 	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);
 }
	/*
	* 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/dma-mapping.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 0
	typedef 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)
	{
	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,
	IRQF_DISABLED, 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->sg) {
	dma->sg = &dma->buf;
	dma->sgcount = 1;
	dma->buf.length = dma->count;
	dma->buf.dma_address = dma_map_single(NULL,
	dma->addr, dma->count,
	dma->dma_mode == DMA_MODE_READ ?
	DMA_FROM_DEVICE : DMA_TO_DEVICE);
	}

	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->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->count;
	regs.ARM_r10 = (unsigned long)dma->addr;
	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);
	}