/*
* Raspberry Pi emulation (c) 2012 Gregory Estrade
* This code is licensed under the GNU GPLv2 and later.
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "hw/dma/bcm2835_dma.h"
#include "qemu/log.h"
/* DMA CS Control and Status bits */
#define BCM2708_DMA_ACTIVE (1 << 0)
#define BCM2708_DMA_END (1 << 1) /* GE */
#define BCM2708_DMA_INT (1 << 2)
#define BCM2708_DMA_ISPAUSED (1 << 4) /* Pause requested or not active */
#define BCM2708_DMA_ISHELD (1 << 5) /* Is held by DREQ flow control */
#define BCM2708_DMA_ERR (1 << 8)
#define BCM2708_DMA_ABORT (1 << 30) /* stop current CB, go to next, WO */
#define BCM2708_DMA_RESET (1 << 31) /* WO, self clearing */
/* DMA control block "info" field bits */
#define BCM2708_DMA_INT_EN (1 << 0)
#define BCM2708_DMA_TDMODE (1 << 1)
#define BCM2708_DMA_WAIT_RESP (1 << 3)
#define BCM2708_DMA_D_INC (1 << 4)
#define BCM2708_DMA_D_WIDTH (1 << 5)
#define BCM2708_DMA_D_DREQ (1 << 6)
#define BCM2708_DMA_D_IGNORE (1 << 7)
#define BCM2708_DMA_S_INC (1 << 8)
#define BCM2708_DMA_S_WIDTH (1 << 9)
#define BCM2708_DMA_S_DREQ (1 << 10)
#define BCM2708_DMA_S_IGNORE (1 << 11)
/* Register offsets */
#define BCM2708_DMA_CS 0x00 /* Control and Status */
#define BCM2708_DMA_ADDR 0x04 /* Control block address */
/* the current control block appears in the following registers - read only */
#define BCM2708_DMA_INFO 0x08
#define BCM2708_DMA_SOURCE_AD 0x0c
#define BCM2708_DMA_DEST_AD 0x10
#define BCM2708_DMA_TXFR_LEN 0x14
#define BCM2708_DMA_STRIDE 0x18
#define BCM2708_DMA_NEXTCB 0x1C
#define BCM2708_DMA_DEBUG 0x20
#define BCM2708_DMA_INT_STATUS 0xfe0 /* Interrupt status of each channel */
#define BCM2708_DMA_ENABLE 0xff0 /* Global enable bits for each channel */
#define BCM2708_DMA_CS_RW_MASK 0x30ff0001 /* All RW bits in DMA_CS */
static void bcm2835_dma_update(BCM2835DMAState *s, unsigned c)
{
BCM2835DMAChan *ch = &s->chan[c];
uint32_t data, xlen, ylen;
int16_t dst_stride, src_stride;
if (!(s->enable & (1 << c))) {
return;
}
while ((s->enable & (1 << c)) && (ch->conblk_ad != 0)) {
/* CB fetch */
ch->ti = ldl_le_phys(&s->dma_as, ch->conblk_ad);
ch->source_ad = ldl_le_phys(&s->dma_as, ch->conblk_ad + 4);
ch->dest_ad = ldl_le_phys(&s->dma_as, ch->conblk_ad + 8);
ch->txfr_len = ldl_le_phys(&s->dma_as, ch->conblk_ad + 12);
ch->stride = ldl_le_phys(&s->dma_as, ch->conblk_ad + 16);
ch->nextconbk = ldl_le_phys(&s->dma_as, ch->conblk_ad + 20);
if (ch->ti & BCM2708_DMA_TDMODE) {
/* 2D transfer mode */
ylen = (ch->txfr_len >> 16) & 0x3fff;
xlen = ch->txfr_len & 0xffff;
dst_stride = ch->stride >> 16;
src_stride = ch->stride & 0xffff;
} else {
ylen = 1;
xlen = ch->txfr_len;
dst_stride = 0;
src_stride = 0;
}
while (ylen != 0) {
/* Normal transfer mode */
while (xlen != 0) {
if (ch->ti & BCM2708_DMA_S_IGNORE) {
/* Ignore reads */
data = 0;
} else {
data = ldl_le_phys(&s->dma_as, ch->source_ad);
}
if (ch->ti & BCM2708_DMA_S_INC) {
ch->source_ad += 4;
}
if (ch->ti & BCM2708_DMA_D_IGNORE) {
/* Ignore writes */
} else {
stl_le_phys(&s->dma_as, ch->dest_ad, data);
}
if (ch->ti & BCM2708_DMA_D_INC) {
ch->dest_ad += 4;
}
/* update remaining transfer length */
xlen -= 4;
if (ch->ti & BCM2708_DMA_TDMODE) {
ch->txfr_len = (ylen << 16) | xlen;
} else {
ch->txfr_len = xlen;
}
}
if (--ylen != 0) {
ch->source_ad += src_stride;
ch->dest_ad += dst_stride;
}
}
ch->cs |= BCM2708_DMA_END;
if (ch->ti & BCM2708_DMA_INT_EN) {
ch->cs |= BCM2708_DMA_INT;
s->int_status |= (1 << c);
qemu_set_irq(ch->irq, 1);
}
/* Process next CB */
ch->conblk_ad = ch->nextconbk;
}
ch->cs &= ~BCM2708_DMA_ACTIVE;
ch->cs |= BCM2708_DMA_ISPAUSED;
}
static void bcm2835_dma_chan_reset(BCM2835DMAChan *ch)
{
ch->cs = 0;
ch->conblk_ad = 0;
}
static uint64_t bcm2835_dma_read(BCM2835DMAState *s, hwaddr offset,
unsigned size, unsigned c)
{
BCM2835DMAChan *ch;
uint32_t res = 0;
assert(size == 4);
assert(c < BCM2835_DMA_NCHANS);
ch = &s->chan[c];
switch (offset) {
case BCM2708_DMA_CS:
res = ch->cs;
break;
case BCM2708_DMA_ADDR:
res = ch->conblk_ad;
break;
case BCM2708_DMA_INFO:
res = ch->ti;
break;
case BCM2708_DMA_SOURCE_AD:
res = ch->source_ad;
break;
case BCM2708_DMA_DEST_AD:
res = ch->dest_ad;
break;
case BCM2708_DMA_TXFR_LEN:
res = ch->txfr_len;
break;
case BCM2708_DMA_STRIDE:
res = ch->stride;
break;
case BCM2708_DMA_NEXTCB:
res = ch->nextconbk;
break;
case BCM2708_DMA_DEBUG:
res = ch->debug;
break;
default:
qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
__func__, offset);
break;
}
return res;
}
static void bcm2835_dma_write(BCM2835DMAState *s, hwaddr offset,
uint64_t value, unsigned size, unsigned c)
{
BCM2835DMAChan *ch;
uint32_t oldcs;
assert(size == 4);
assert(c < BCM2835_DMA_NCHANS);
ch = &s->chan[c];
switch (offset) {
case BCM2708_DMA_CS:
oldcs = ch->cs;
if (value & BCM2708_DMA_RESET) {
bcm2835_dma_chan_reset(ch);
}
if (value & BCM2708_DMA_ABORT) {
/* abort is a no-op, since we always run to completion */
}
if (value & BCM2708_DMA_END) {
ch->cs &= ~BCM2708_DMA_END;
}
if (value & BCM2708_DMA_INT) {
ch->cs &= ~BCM2708_DMA_INT;
s->int_status &= ~(1 << c);
qemu_set_irq(ch->irq, 0);
}
ch->cs &= ~BCM2708_DMA_CS_RW_MASK;
ch->cs |= (value & BCM2708_DMA_CS_RW_MASK);
if (!(oldcs & BCM2708_DMA_ACTIVE) && (ch->cs & BCM2708_DMA_ACTIVE)) {
bcm2835_dma_update(s, c);
}
break;
case BCM2708_DMA_ADDR:
ch->conblk_ad = value;
break;
case BCM2708_DMA_DEBUG:
ch->debug = value;
break;
default:
qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
__func__, offset);
break;
}
}
static uint64_t bcm2835_dma0_read(void *opaque, hwaddr offset, unsigned size)
{
BCM2835DMAState *s = opaque;
if (offset < 0xf00) {
return bcm2835_dma_read(s, (offset & 0xff), size, (offset >> 8) & 0xf);
} else {
switch (offset) {
case BCM2708_DMA_INT_STATUS:
return s->int_status;
case BCM2708_DMA_ENABLE:
return s->enable;
default:
qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
__func__, offset);
return 0;
}
}
}
static uint64_t bcm2835_dma15_read(void *opaque, hwaddr offset, unsigned size)
{
return bcm2835_dma_read(opaque, (offset & 0xff), size, 15);
}
static void bcm2835_dma0_write(void *opaque, hwaddr offset, uint64_t value,
unsigned size)
{
BCM2835DMAState *s = opaque;
if (offset < 0xf00) {
bcm2835_dma_write(s, (offset & 0xff), value, size, (offset >> 8) & 0xf);
} else {
switch (offset) {
case BCM2708_DMA_INT_STATUS:
break;
case BCM2708_DMA_ENABLE:
s->enable = (value & 0xffff);
break;
default:
qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
__func__, offset);
}
}
}
static void bcm2835_dma15_write(void *opaque, hwaddr offset, uint64_t value,
unsigned size)
{
bcm2835_dma_write(opaque, (offset & 0xff), value, size, 15);
}
static const MemoryRegionOps bcm2835_dma0_ops = {
.read = bcm2835_dma0_read,
.write = bcm2835_dma0_write,
.endianness = DEVICE_NATIVE_ENDIAN,
.valid.min_access_size = 4,
.valid.max_access_size = 4,
};
static const MemoryRegionOps bcm2835_dma15_ops = {
.read = bcm2835_dma15_read,
.write = bcm2835_dma15_write,
.endianness = DEVICE_NATIVE_ENDIAN,
.valid.min_access_size = 4,
.valid.max_access_size = 4,
};
static const VMStateDescription vmstate_bcm2835_dma_chan = {
.name = TYPE_BCM2835_DMA "-chan",
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_UINT32(cs, BCM2835DMAChan),
VMSTATE_UINT32(conblk_ad, BCM2835DMAChan),
VMSTATE_UINT32(ti, BCM2835DMAChan),
VMSTATE_UINT32(source_ad, BCM2835DMAChan),
VMSTATE_UINT32(dest_ad, BCM2835DMAChan),
VMSTATE_UINT32(txfr_len, BCM2835DMAChan),
VMSTATE_UINT32(stride, BCM2835DMAChan),
VMSTATE_UINT32(nextconbk, BCM2835DMAChan),
VMSTATE_UINT32(debug, BCM2835DMAChan),
VMSTATE_END_OF_LIST()
}
};
static const VMStateDescription vmstate_bcm2835_dma = {
.name = TYPE_BCM2835_DMA,
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_STRUCT_ARRAY(chan, BCM2835DMAState, BCM2835_DMA_NCHANS, 1,
vmstate_bcm2835_dma_chan, BCM2835DMAChan),
VMSTATE_UINT32(int_status, BCM2835DMAState),
VMSTATE_UINT32(enable, BCM2835DMAState),
VMSTATE_END_OF_LIST()
}
};
static void bcm2835_dma_init(Object *obj)
{
BCM2835DMAState *s = BCM2835_DMA(obj);
int n;
/* DMA channels 0-14 occupy a contiguous block of IO memory, along
* with the global enable and interrupt status bits. Channel 15
* has the same register map, but is mapped at a discontiguous
* address in a separate IO block.
*/
memory_region_init_io(&s->iomem0, OBJECT(s), &bcm2835_dma0_ops, s,
TYPE_BCM2835_DMA, 0x1000);
sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem0);
memory_region_init_io(&s->iomem15, OBJECT(s), &bcm2835_dma15_ops, s,
TYPE_BCM2835_DMA "-chan15", 0x100);
sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem15);
for (n = 0; n < 16; n++) {
sysbus_init_irq(SYS_BUS_DEVICE(s), &s->chan[n].irq);
}
}
static void bcm2835_dma_reset(DeviceState *dev)
{
BCM2835DMAState *s = BCM2835_DMA(dev);
int n;
s->enable = 0xffff;
s->int_status = 0;
for (n = 0; n < BCM2835_DMA_NCHANS; n++) {
bcm2835_dma_chan_reset(&s->chan[n]);
}
}
static void bcm2835_dma_realize(DeviceState *dev, Error **errp)
{
BCM2835DMAState *s = BCM2835_DMA(dev);
Error *err = NULL;
Object *obj;
obj = object_property_get_link(OBJECT(dev), "dma-mr", &err);
if (obj == NULL) {
error_setg(errp, "%s: required dma-mr link not found: %s",
__func__, error_get_pretty(err));
return;
}
s->dma_mr = MEMORY_REGION(obj);
address_space_init(&s->dma_as, s->dma_mr, NULL);
bcm2835_dma_reset(dev);
}
static void bcm2835_dma_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->realize = bcm2835_dma_realize;
dc->reset = bcm2835_dma_reset;
dc->vmsd = &vmstate_bcm2835_dma;
}
static TypeInfo bcm2835_dma_info = {
.name = TYPE_BCM2835_DMA,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(BCM2835DMAState),
.class_init = bcm2835_dma_class_init,
.instance_init = bcm2835_dma_init,
};
static void bcm2835_dma_register_types(void)
{
type_register_static(&bcm2835_dma_info);
}
type_init(bcm2835_dma_register_types)
