/*
* QEMU ETRAX DMA Controller.
*
* Copyright (c) 2008 Edgar E. Iglesias, Axis Communications AB.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "hw/hw.h"
#include "hw/irq.h"
#include "qemu/main-loop.h"
#include "sysemu/runstate.h"
#include "exec/address-spaces.h"
#include "hw/cris/etraxfs_dma.h"
#define D(x)
#define RW_DATA (0x0 / 4)
#define RW_SAVED_DATA (0x58 / 4)
#define RW_SAVED_DATA_BUF (0x5c / 4)
#define RW_GROUP (0x60 / 4)
#define RW_GROUP_DOWN (0x7c / 4)
#define RW_CMD (0x80 / 4)
#define RW_CFG (0x84 / 4)
#define RW_STAT (0x88 / 4)
#define RW_INTR_MASK (0x8c / 4)
#define RW_ACK_INTR (0x90 / 4)
#define R_INTR (0x94 / 4)
#define R_MASKED_INTR (0x98 / 4)
#define RW_STREAM_CMD (0x9c / 4)
#define DMA_REG_MAX (0x100 / 4)
/* descriptors */
// ------------------------------------------------------------ dma_descr_group
typedef struct dma_descr_group {
uint32_t next;
unsigned eol : 1;
unsigned tol : 1;
unsigned bol : 1;
unsigned : 1;
unsigned intr : 1;
unsigned : 2;
unsigned en : 1;
unsigned : 7;
unsigned dis : 1;
unsigned md : 16;
struct dma_descr_group *up;
union {
struct dma_descr_context *context;
struct dma_descr_group *group;
} down;
} dma_descr_group;
// ---------------------------------------------------------- dma_descr_context
typedef struct dma_descr_context {
uint32_t next;
unsigned eol : 1;
unsigned : 3;
unsigned intr : 1;
unsigned : 1;
unsigned store_mode : 1;
unsigned en : 1;
unsigned : 7;
unsigned dis : 1;
unsigned md0 : 16;
unsigned md1;
unsigned md2;
unsigned md3;
unsigned md4;
uint32_t saved_data;
uint32_t saved_data_buf;
} dma_descr_context;
// ------------------------------------------------------------- dma_descr_data
typedef struct dma_descr_data {
uint32_t next;
uint32_t buf;
unsigned eol : 1;
unsigned : 2;
unsigned out_eop : 1;
unsigned intr : 1;
unsigned wait : 1;
unsigned : 2;
unsigned : 3;
unsigned in_eop : 1;
unsigned : 4;
unsigned md : 16;
uint32_t after;
} dma_descr_data;
/* Constants */
enum {
regk_dma_ack_pkt = 0x00000100,
regk_dma_anytime = 0x00000001,
regk_dma_array = 0x00000008,
regk_dma_burst = 0x00000020,
regk_dma_client = 0x00000002,
regk_dma_copy_next = 0x00000010,
regk_dma_copy_up = 0x00000020,
regk_dma_data_at_eol = 0x00000001,
regk_dma_dis_c = 0x00000010,
regk_dma_dis_g = 0x00000020,
regk_dma_idle = 0x00000001,
regk_dma_intern = 0x00000004,
regk_dma_load_c = 0x00000200,
regk_dma_load_c_n = 0x00000280,
regk_dma_load_c_next = 0x00000240,
regk_dma_load_d = 0x00000140,
regk_dma_load_g = 0x00000300,
regk_dma_load_g_down = 0x000003c0,
regk_dma_load_g_next = 0x00000340,
regk_dma_load_g_up = 0x00000380,
regk_dma_next_en = 0x00000010,
regk_dma_next_pkt = 0x00000010,
regk_dma_no = 0x00000000,
regk_dma_only_at_wait = 0x00000000,
regk_dma_restore = 0x00000020,
regk_dma_rst = 0x00000001,
regk_dma_running = 0x00000004,
regk_dma_rw_cfg_default = 0x00000000,
regk_dma_rw_cmd_default = 0x00000000,
regk_dma_rw_intr_mask_default = 0x00000000,
regk_dma_rw_stat_default = 0x00000101,
regk_dma_rw_stream_cmd_default = 0x00000000,
regk_dma_save_down = 0x00000020,
regk_dma_save_up = 0x00000020,
regk_dma_set_reg = 0x00000050,
regk_dma_set_w_size1 = 0x00000190,
regk_dma_set_w_size2 = 0x000001a0,
regk_dma_set_w_size4 = 0x000001c0,
regk_dma_stopped = 0x00000002,
regk_dma_store_c = 0x00000002,
regk_dma_store_descr = 0x00000000,
regk_dma_store_g = 0x00000004,
regk_dma_store_md = 0x00000001,
regk_dma_sw = 0x00000008,
regk_dma_update_down = 0x00000020,
regk_dma_yes = 0x00000001
};
enum dma_ch_state
{
RST = 1,
STOPPED = 2,
RUNNING = 4
};
struct fs_dma_channel
{
qemu_irq irq;
struct etraxfs_dma_client *client;
/* Internal status. */
int stream_cmd_src;
enum dma_ch_state state;
unsigned int input : 1;
unsigned int eol : 1;
struct dma_descr_group current_g;
struct dma_descr_context current_c;
struct dma_descr_data current_d;
/* Control registers. */
uint32_t regs[DMA_REG_MAX];
};
struct fs_dma_ctrl
{
MemoryRegion mmio;
int nr_channels;
struct fs_dma_channel *channels;
QEMUBH *bh;
};
static void DMA_run(void *opaque);
static int channel_out_run(struct fs_dma_ctrl *ctrl, int c);
static inline uint32_t channel_reg(struct fs_dma_ctrl *ctrl, int c, int reg)
{
return ctrl->channels[c].regs[reg];
}
static inline int channel_stopped(struct fs_dma_ctrl *ctrl, int c)
{
return channel_reg(ctrl, c, RW_CFG) & 2;
}
static inline int channel_en(struct fs_dma_ctrl *ctrl, int c)
{
return (channel_reg(ctrl, c, RW_CFG) & 1)
&& ctrl->channels[c].client;
}
static inline int fs_channel(hwaddr addr)
{
/* Every channel has a 0x2000 ctrl register map. */
return addr >> 13;
}
#ifdef USE_THIS_DEAD_CODE
static void channel_load_g(struct fs_dma_ctrl *ctrl, int c)
{
hwaddr addr = channel_reg(ctrl, c, RW_GROUP);
/* Load and decode. FIXME: handle endianness. */
cpu_physical_memory_read(addr, &ctrl->channels[c].current_g,
sizeof(ctrl->channels[c].current_g));
}
static void dump_c(int ch, struct dma_descr_context *c)
{
printf("%s ch=%d\n", __func__, ch);
printf("next=%x\n", c->next);
printf("saved_data=%x\n", c->saved_data);
printf("saved_data_buf=%x\n", c->saved_data_buf);
printf("eol=%x\n", (uint32_t) c->eol);
}
static void dump_d(int ch, struct dma_descr_data *d)
{
printf("%s ch=%d\n", __func__, ch);
printf("next=%x\n", d->next);
printf("buf=%x\n", d->buf);
printf("after=%x\n", d->after);
printf("intr=%x\n", (uint32_t) d->intr);
printf("out_eop=%x\n", (uint32_t) d->out_eop);
printf("in_eop=%x\n", (uint32_t) d->in_eop);
printf("eol=%x\n", (uint32_t) d->eol);
}
#endif
static void channel_load_c(struct fs_dma_ctrl *ctrl, int c)
{
hwaddr addr = channel_reg(ctrl, c, RW_GROUP_DOWN);
/* Load and decode. FIXME: handle endianness. */
cpu_physical_memory_read(addr, &ctrl->channels[c].current_c,
sizeof(ctrl->channels[c].current_c));
D(dump_c(c, &ctrl->channels[c].current_c));
/* I guess this should update the current pos. */
ctrl->channels[c].regs[RW_SAVED_DATA] =
(uint32_t)(unsigned long)ctrl->channels[c].current_c.saved_data;
ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
(uint32_t)(unsigned long)ctrl->channels[c].current_c.saved_data_buf;
}
static void channel_load_d(struct fs_dma_ctrl *ctrl, int c)
{
hwaddr addr = channel_reg(ctrl, c, RW_SAVED_DATA);
/* Load and decode. FIXME: handle endianness. */
D(printf("%s ch=%d addr=" TARGET_FMT_plx "\n", __func__, c, addr));
cpu_physical_memory_read(addr, &ctrl->channels[c].current_d,
sizeof(ctrl->channels[c].current_d));
D(dump_d(c, &ctrl->channels[c].current_d));
ctrl->channels[c].regs[RW_DATA] = addr;
}
static void channel_store_c(struct fs_dma_ctrl *ctrl, int c)
{
hwaddr addr = channel_reg(ctrl, c, RW_GROUP_DOWN);
/* Encode and store. FIXME: handle endianness. */
D(printf("%s ch=%d addr=" TARGET_FMT_plx "\n", __func__, c, addr));
D(dump_d(c, &ctrl->channels[c].current_d));
cpu_physical_memory_write(addr, &ctrl->channels[c].current_c,
sizeof(ctrl->channels[c].current_c));
}
static void channel_store_d(struct fs_dma_ctrl *ctrl, int c)
{
hwaddr addr = channel_reg(ctrl, c, RW_SAVED_DATA);
/* Encode and store. FIXME: handle endianness. */
D(printf("%s ch=%d addr=" TARGET_FMT_plx "\n", __func__, c, addr));
cpu_physical_memory_write(addr, &ctrl->channels[c].current_d,
sizeof(ctrl->channels[c].current_d));
}
static inline void channel_stop(struct fs_dma_ctrl *ctrl, int c)
{
/* FIXME: */
}
static inline void channel_start(struct fs_dma_ctrl *ctrl, int c)
{
if (ctrl->channels[c].client)
{
ctrl->channels[c].eol = 0;
ctrl->channels[c].state = RUNNING;
if (!ctrl->channels[c].input)
channel_out_run(ctrl, c);
} else
printf("WARNING: starting DMA ch %d with no client\n", c);
qemu_bh_schedule_idle(ctrl->bh);
}
static void channel_continue(struct fs_dma_ctrl *ctrl, int c)
{
if (!channel_en(ctrl, c)
|| channel_stopped(ctrl, c)
|| ctrl->channels[c].state != RUNNING
/* Only reload the current data descriptor if it has eol set. */
|| !ctrl->channels[c].current_d.eol) {
D(printf("continue failed ch=%d state=%d stopped=%d en=%d eol=%d\n",
c, ctrl->channels[c].state,
channel_stopped(ctrl, c),
channel_en(ctrl,c),
ctrl->channels[c].eol));
D(dump_d(c, &ctrl->channels[c].current_d));
return;
}
/* Reload the current descriptor. */
channel_load_d(ctrl, c);
/* If the current descriptor cleared the eol flag and we had already
reached eol state, do the continue. */
if (!ctrl->channels[c].current_d.eol && ctrl->channels[c].eol) {
D(printf("continue %d ok %x\n", c,
ctrl->channels[c].current_d.next));
ctrl->channels[c].regs[RW_SAVED_DATA] =
(uint32_t)(unsigned long)ctrl->channels[c].current_d.next;
channel_load_d(ctrl, c);
ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
(uint32_t)(unsigned long)ctrl->channels[c].current_d.buf;
channel_start(ctrl, c);
}
ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
(uint32_t)(unsigned long)ctrl->channels[c].current_d.buf;
}
static void channel_stream_cmd(struct fs_dma_ctrl *ctrl, int c, uint32_t v)
{
unsigned int cmd = v & ((1 << 10) - 1);
D(printf("%s ch=%d cmd=%x\n",
__func__, c, cmd));
if (cmd & regk_dma_load_d) {
channel_load_d(ctrl, c);
if (cmd & regk_dma_burst)
channel_start(ctrl, c);
}
if (cmd & regk_dma_load_c) {
channel_load_c(ctrl, c);
}
}
static void channel_update_irq(struct fs_dma_ctrl *ctrl, int c)
{
D(printf("%s %d\n", __func__, c));
ctrl->channels[c].regs[R_INTR] &=
~(ctrl->channels[c].regs[RW_ACK_INTR]);
ctrl->channels[c].regs[R_MASKED_INTR] =
ctrl->channels[c].regs[R_INTR]
& ctrl->channels[c].regs[RW_INTR_MASK];
D(printf("%s: chan=%d masked_intr=%x\n", __func__,
c,
ctrl->channels[c].regs[R_MASKED_INTR]));
qemu_set_irq(ctrl->channels[c].irq,
!!ctrl->channels[c].regs[R_MASKED_INTR]);
}
static int channel_out_run(struct fs_dma_ctrl *ctrl, int c)
{
uint32_t len;
uint32_t saved_data_buf;
unsigned char buf[2 * 1024];
struct dma_context_metadata meta;
bool send_context = true;
if (ctrl->channels[c].eol)
return 0;
do {
bool out_eop;
D(printf("ch=%d buf=%x after=%x\n",
c,
(uint32_t)ctrl->channels[c].current_d.buf,
(uint32_t)ctrl->channels[c].current_d.after));
if (send_context) {
if (ctrl->channels[c].client->client.metadata_push) {
meta.metadata = ctrl->channels[c].current_d.md;
ctrl->channels[c].client->client.metadata_push(
ctrl->channels[c].client->client.opaque,
&meta);
}
send_context = false;
}
channel_load_d(ctrl, c);
saved_data_buf = channel_reg(ctrl, c, RW_SAVED_DATA_BUF);
len = (uint32_t)(unsigned long)
ctrl->channels[c].current_d.after;
len -= saved_data_buf;
if (len > sizeof buf)
len = sizeof buf;
cpu_physical_memory_read (saved_data_buf, buf, len);
out_eop = ((saved_data_buf + len) ==
ctrl->channels[c].current_d.after) &&
ctrl->channels[c].current_d.out_eop;
D(printf("channel %d pushes %x %u bytes eop=%u\n", c,
saved_data_buf, len, out_eop));
if (ctrl->channels[c].client->client.push) {
if (len > 0) {
ctrl->channels[c].client->client.push(
ctrl->channels[c].client->client.opaque,
buf, len, out_eop);
}
} else {
printf("WARNING: DMA ch%d dataloss,"
" no attached client.\n", c);
}
saved_data_buf += len;
if (saved_data_buf == (uint32_t)(unsigned long)
ctrl->channels[c].current_d.after) {
/* Done. Step to next. */
if (ctrl->channels[c].current_d.out_eop) {
send_context = true;
}
if (ctrl->channels[c].current_d.intr) {
/* data intr. */
D(printf("signal intr %d eol=%d\n",
len, ctrl->channels[c].current_d.eol));
ctrl->channels[c].regs[R_INTR] |= (1 << 2);
channel_update_irq(ctrl, c);
}
channel_store_d(ctrl, c);
if (ctrl->channels[c].current_d.eol) {
D(printf("channel %d EOL\n", c));
ctrl->channels[c].eol = 1;
/* Mark the context as disabled. */
ctrl->channels[c].current_c.dis = 1;
channel_store_c(ctrl, c);
channel_stop(ctrl, c);
} else {
ctrl->channels[c].regs[RW_SAVED_DATA] =
(uint32_t)(unsigned long)ctrl->
channels[c].current_d.next;
/* Load new descriptor. */
channel_load_d(ctrl, c);
saved_data_buf = (uint32_t)(unsigned long)
ctrl->channels[c].current_d.buf;
}
ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
saved_data_buf;
D(dump_d(c, &ctrl->channels[c].current_d));
}
ctrl->channels[c].regs[RW_SAVED_DATA_BUF] = saved_data_buf;
} while (!ctrl->channels[c].eol);
return 1;
}
static int channel_in_process(struct fs_dma_ctrl *ctrl, int c,
unsigned char *buf, int buflen, int eop)
{
uint32_t len;
uint32_t saved_data_buf;
if (ctrl->channels[c].eol == 1)
return 0;
channel_load_d(ctrl, c);
saved_data_buf = channel_reg(ctrl, c, RW_SAVED_DATA_BUF);
len = (uint32_t)(unsigned long)ctrl->channels[c].current_d.after;
len -= saved_data_buf;
if (len > buflen)
len = buflen;
cpu_physical_memory_write (saved_data_buf, buf, len);
saved_data_buf += len;
if (saved_data_buf ==
(uint32_t)(unsigned long)ctrl->channels[c].current_d.after
|| eop) {
uint32_t r_intr = ctrl->channels[c].regs[R_INTR];
D(printf("in dscr end len=%d\n",
ctrl->channels[c].current_d.after
- ctrl->channels[c].current_d.buf));
ctrl->channels[c].current_d.after = saved_data_buf;
/* Done. Step to next. */
if (ctrl->channels[c].current_d.intr) {
/* TODO: signal eop to the client. */
/* data intr. */
ctrl->channels[c].regs[R_INTR] |= 3;
}
if (eop) {
ctrl->channels[c].current_d.in_eop = 1;
ctrl->channels[c].regs[R_INTR] |= 8;
}
if (r_intr != ctrl->channels[c].regs[R_INTR])
channel_update_irq(ctrl, c);
channel_store_d(ctrl, c);
D(dump_d(c, &ctrl->channels[c].current_d));
if (ctrl->channels[c].current_d.eol) {
D(printf("channel %d EOL\n", c));
ctrl->channels[c].eol = 1;
/* Mark the context as disabled. */
ctrl->channels[c].current_c.dis = 1;
channel_store_c(ctrl, c);
channel_stop(ctrl, c);
} else {
ctrl->channels[c].regs[RW_SAVED_DATA] =
(uint32_t)(unsigned long)ctrl->
channels[c].current_d.next;
/* Load new descriptor. */
channel_load_d(ctrl, c);
saved_data_buf = (uint32_t)(unsigned long)
ctrl->channels[c].current_d.buf;
}
}
ctrl->channels[c].regs[RW_SAVED_DATA_BUF] = saved_data_buf;
return len;
}
static inline int channel_in_run(struct fs_dma_ctrl *ctrl, int c)
{
if (ctrl->channels[c].client->client.pull) {
ctrl->channels[c].client->client.pull(
ctrl->channels[c].client->client.opaque);
return 1;
} else
return 0;
}
static uint32_t dma_rinvalid (void *opaque, hwaddr addr)
{
hw_error("Unsupported short raccess. reg=" TARGET_FMT_plx "\n", addr);
return 0;
}
static uint64_t
dma_read(void *opaque, hwaddr addr, unsigned int size)
{
struct fs_dma_ctrl *ctrl = opaque;
int c;
uint32_t r = 0;
if (size != 4) {
dma_rinvalid(opaque, addr);
}
/* Make addr relative to this channel and bounded to nr regs. */
c = fs_channel(addr);
addr &= 0xff;
addr >>= 2;
switch (addr)
{
case RW_STAT:
r = ctrl->channels[c].state & 7;
r |= ctrl->channels[c].eol << 5;
r |= ctrl->channels[c].stream_cmd_src << 8;
break;
default:
r = ctrl->channels[c].regs[addr];
D(printf ("%s c=%d addr=" TARGET_FMT_plx "\n",
__func__, c, addr));
break;
}
return r;
}
static void
dma_winvalid (void *opaque, hwaddr addr, uint32_t value)
{
hw_error("Unsupported short waccess. reg=" TARGET_FMT_plx "\n", addr);
}
static void
dma_update_state(struct fs_dma_ctrl *ctrl, int c)
{
if (ctrl->channels[c].regs[RW_CFG] & 2)
ctrl->channels[c].state = STOPPED;
if (!(ctrl->channels[c].regs[RW_CFG] & 1))
ctrl->channels[c].state = RST;
}
static void
dma_write(void *opaque, hwaddr addr,
uint64_t val64, unsigned int size)
{
struct fs_dma_ctrl *ctrl = opaque;
uint32_t value = val64;
int c;
if (size != 4) {
dma_winvalid(opaque, addr, value);
}
/* Make addr relative to this channel and bounded to nr regs. */
c = fs_channel(addr);
addr &= 0xff;
addr >>= 2;
switch (addr)
{
case RW_DATA:
ctrl->channels[c].regs[addr] = value;
break;
case RW_CFG:
ctrl->channels[c].regs[addr] = value;
dma_update_state(ctrl, c);
break;
case RW_CMD:
/* continue. */
if (value & ~1)
printf("Invalid store to ch=%d RW_CMD %x\n",
c, value);
ctrl->channels[c].regs[addr] = value;
channel_continue(ctrl, c);
break;
case RW_SAVED_DATA:
case RW_SAVED_DATA_BUF:
case RW_GROUP:
case RW_GROUP_DOWN:
ctrl->channels[c].regs[addr] = value;
break;
case RW_ACK_INTR:
case RW_INTR_MASK:
ctrl->channels[c].regs[addr] = value;
channel_update_irq(ctrl, c);
if (addr == RW_ACK_INTR)
ctrl->channels[c].regs[RW_ACK_INTR] = 0;
break;
case RW_STREAM_CMD:
if (value & ~1023)
printf("Invalid store to ch=%d "
"RW_STREAMCMD %x\n",
c, value);
ctrl->channels[c].regs[addr] = value;
D(printf("stream_cmd ch=%d\n", c));
channel_stream_cmd(ctrl, c, value);
break;
default:
D(printf ("%s c=%d " TARGET_FMT_plx "\n",
__func__, c, addr));
break;
}
}
static const MemoryRegionOps dma_ops = {
.read = dma_read,
.write = dma_write,
.endianness = DEVICE_NATIVE_ENDIAN,
.valid = {
.min_access_size = 1,
.max_access_size = 4
}
};
static int etraxfs_dmac_run(void *opaque)
{
struct fs_dma_ctrl *ctrl = opaque;
int i;
int p = 0;
for (i = 0;
i < ctrl->nr_channels;
i++)
{
if (ctrl->channels[i].state == RUNNING)
{
if (ctrl->channels[i].input) {
p += channel_in_run(ctrl, i);
} else {
p += channel_out_run(ctrl, i);
}
}
}
return p;
}
int etraxfs_dmac_input(struct etraxfs_dma_client *client,
void *buf, int len, int eop)
{
return channel_in_process(client->ctrl, client->channel,
buf, len, eop);
}
/* Connect an IRQ line with a channel. */
void etraxfs_dmac_connect(void *opaque, int c, qemu_irq *line, int input)
{
struct fs_dma_ctrl *ctrl = opaque;
ctrl->channels[c].irq = *line;
ctrl->channels[c].input = input;
}
void etraxfs_dmac_connect_client(void *opaque, int c,
struct etraxfs_dma_client *cl)
{
struct fs_dma_ctrl *ctrl = opaque;
cl->ctrl = ctrl;
cl->channel = c;
ctrl->channels[c].client = cl;
}
static void DMA_run(void *opaque)
{
struct fs_dma_ctrl *etraxfs_dmac = opaque;
int p = 1;
if (runstate_is_running())
p = etraxfs_dmac_run(etraxfs_dmac);
if (p)
qemu_bh_schedule_idle(etraxfs_dmac->bh);
}
void *etraxfs_dmac_init(hwaddr base, int nr_channels)
{
struct fs_dma_ctrl *ctrl = NULL;
ctrl = g_malloc0(sizeof *ctrl);
ctrl->bh = qemu_bh_new(DMA_run, ctrl);
ctrl->nr_channels = nr_channels;
ctrl->channels = g_malloc0(sizeof ctrl->channels[0] * nr_channels);
memory_region_init_io(&ctrl->mmio, NULL, &dma_ops, ctrl, "etraxfs-dma",
nr_channels * 0x2000);
memory_region_add_subregion(get_system_memory(), base, &ctrl->mmio);
return ctrl;
}
