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linux/arch/arm/mach-rpc/dma.c
Russell King 7cdad48297 [ARM] Remove '__address' from scatterlist and convert to DMA API 
The old __address element in struct scatterlist remained from older
kernels because the ARM DMA emulation code made use of it.  Move
this field into struct dma_struct, and convert DMA emulation code
to setup a SG entry as required.

Also, convert DMA emulation code to use the new DMA API rather
than the PCI DMA API.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-04 15:08:30 +00:00

342 lines
7.3 KiB
C
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/*
* 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, 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->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);
}
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