Add support for parts of the etraxfs dma controller.

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4428 c046a42c-6fe2-441c-8c8c-71466251a162

2 files changed, 718 insertions, 0 deletions

diff --git a/hw/etraxfs_dma.c b/hw/etraxfs_dma.c
new file mode 100644
index 0000000000..a090a6d6b0
--- /dev/null
+++ b/hw/etraxfs_dma.c
@@ -0,0 +1,694 @@
+/*
+ * 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 <stdio.h>
+#include <sys/time.h>
+#include "hw.h"
+
+#include "etraxfs_dma.h"
+
+#define D(x)
+
+#define RW_DATA           0x0
+#define RW_SAVED_DATA     0x58
+#define RW_SAVED_DATA_BUF 0x5c
+#define RW_GROUP          0x60
+#define RW_GROUP_DOWN     0x7c
+#define RW_CMD            0x80
+#define RW_CFG            0x84
+#define RW_STAT           0x88
+#define RW_INTR_MASK      0x8c
+#define RW_ACK_INTR       0x90
+#define R_INTR            0x94
+#define R_MASKED_INTR     0x98
+#define RW_STREAM_CMD     0x9c
+
+#define DMA_REG_MAX   0x100
+
+/* descriptors */
+
+// ------------------------------------------------------------ dma_descr_group
+typedef struct dma_descr_group {
+  struct dma_descr_group       *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 {
+  struct dma_descr_context     *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;
+  struct dma_descr_data        *saved_data;
+  char                         *saved_data_buf;
+} dma_descr_context;
+
+// ------------------------------------------------------------- dma_descr_data
+typedef struct dma_descr_data {
+  struct dma_descr_data        *next;
+  char                         *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;
+  char                         *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 = 0,
+	STOPPED = 2,
+	RUNNING = 4
+};
+
+struct fs_dma_channel
+{
+	int regmap;
+	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;
+
+	/* Controll registers.  */
+	uint32_t regs[DMA_REG_MAX];
+};
+
+struct fs_dma_ctrl
+{
+	CPUState *env;
+	target_phys_addr_t base;
+
+	int nr_channels;
+	struct fs_dma_channel *channels;
+};
+
+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(target_phys_addr_t base, target_phys_addr_t addr)
+{
+	/* Every channel has a 0x2000 ctrl register map.  */
+	return (addr - base) >> 13;
+}
+
+static void channel_load_g(struct fs_dma_ctrl *ctrl, int c)
+{
+	target_phys_addr_t addr = channel_reg(ctrl, c, RW_GROUP);
+
+	/* Load and decode. FIXME: handle endianness.  */
+	cpu_physical_memory_read (addr, 
+				  (void *) &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", (uint32_t) c->next);
+	printf("saved_data=%x\n", (uint32_t) c->saved_data);
+	printf("saved_data_buf=%x\n", (uint32_t) 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", (uint32_t) d->next);
+	printf("buf=%x\n", (uint32_t) d->buf);
+	printf("after=%x\n", (uint32_t) 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);
+}
+
+static void channel_load_c(struct fs_dma_ctrl *ctrl, int c)
+{
+	target_phys_addr_t addr = channel_reg(ctrl, c, RW_GROUP_DOWN);
+
+	/* Load and decode. FIXME: handle endianness.  */
+	cpu_physical_memory_read (addr, 
+				  (void *) &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)ctrl->channels[c].current_c.saved_data;
+	ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
+		(uint32_t)ctrl->channels[c].current_c.saved_data_buf;
+}
+
+static void channel_load_d(struct fs_dma_ctrl *ctrl, int c)
+{
+	target_phys_addr_t addr = channel_reg(ctrl, c, RW_SAVED_DATA);
+
+	/* Load and decode. FIXME: handle endianness.  */
+	D(printf("%s addr=%x\n", __func__, addr));
+	cpu_physical_memory_read (addr,
+				  (void *) &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_SAVED_DATA_BUF] =
+		(uint32_t)ctrl->channels[c].current_d.buf;
+}
+
+static void channel_store_d(struct fs_dma_ctrl *ctrl, int c)
+{
+	target_phys_addr_t addr = channel_reg(ctrl, c, RW_SAVED_DATA);
+
+	/* Load and decode. FIXME: handle endianness.  */
+	D(printf("%s addr=%x\n", __func__, addr));
+	cpu_physical_memory_write (addr,
+				  (void *) &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;
+	} else
+		printf("WARNING: starting DMA ch %d with no client\n", c);
+}
+
+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) ctrl->channels[c].current_d.next;
+		channel_load_d(ctrl, c);
+		channel_start(ctrl, c);
+	}
+}
+
+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 cmd=%x\n", __func__, 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]));
+
+        if (ctrl->channels[c].regs[R_MASKED_INTR])
+                qemu_irq_raise(ctrl->channels[c].irq[0]);
+        else
+                qemu_irq_lower(ctrl->channels[c].irq[0]);
+}
+
+static void channel_out_run(struct fs_dma_ctrl *ctrl, int c)
+{
+	uint32_t len;
+	uint32_t saved_data_buf;
+	unsigned char buf[2 * 1024];
+
+	if (ctrl->channels[c].eol == 1)
+		return;
+
+	saved_data_buf = channel_reg(ctrl, c, RW_SAVED_DATA_BUF);
+
+	D(printf("buf=%x after=%x saved_data_buf=%x\n",
+		 (uint32_t)ctrl->channels[c].current_d.buf,
+		 (uint32_t)ctrl->channels[c].current_d.after,
+		 saved_data_buf));
+
+	if (saved_data_buf == (uint32_t)ctrl->channels[c].current_d.after) {
+		/* Done. Step to next.  */
+		if (ctrl->channels[c].current_d.out_eop) {
+			/* TODO: signal eop to the client.  */
+			D(printf("signal eop\n"));
+		}
+		if (ctrl->channels[c].current_d.intr) {
+			/* TODO: signal eop to the client.  */
+			/* data intr.  */
+			D(printf("signal intr\n"));
+			ctrl->channels[c].regs[R_INTR] |= (1 << 2);
+			channel_update_irq(ctrl, c);
+		}
+		if (ctrl->channels[c].current_d.eol) {
+			D(printf("channel %d EOL\n", c));
+			ctrl->channels[c].eol = 1;
+			channel_stop(ctrl, c);
+		} else {
+			ctrl->channels[c].regs[RW_SAVED_DATA] =
+				(uint32_t) ctrl->channels[c].current_d.next;
+			/* Load new descriptor.  */
+			channel_load_d(ctrl, c);
+		}
+
+		channel_store_d(ctrl, c);
+		D(dump_d(c, &ctrl->channels[c].current_d));
+		return;
+	}
+
+	len = (uint32_t) 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);
+
+	D(printf("channel %d pushes %x %u bytes\n", c, 
+		 saved_data_buf, len));
+	/* TODO: Push content.  */
+	if (ctrl->channels[c].client->client.push)
+		ctrl->channels[c].client->client.push(
+			ctrl->channels[c].client->client.opaque, buf, len);
+	else
+		printf("WARNING: DMA ch%d dataloss, no attached client.\n", c);
+
+	ctrl->channels[c].regs[RW_SAVED_DATA_BUF] += len;
+}
+
+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;
+
+	saved_data_buf = channel_reg(ctrl, c, RW_SAVED_DATA_BUF);
+	len = (uint32_t) 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)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 = 
+			(void *) 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;
+			channel_stop(ctrl, c);
+		} else {
+			ctrl->channels[c].regs[RW_SAVED_DATA] =
+				(uint32_t) ctrl->channels[c].current_d.next;
+			/* Load new descriptor.  */
+			channel_load_d(ctrl, c);
+			saved_data_buf =
+				ctrl->channels[c].regs[RW_SAVED_DATA_BUF];
+		}
+	}
+
+	ctrl->channels[c].regs[RW_SAVED_DATA_BUF] = saved_data_buf;
+	return len;
+}
+
+static inline void 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);
+}
+
+static uint32_t dma_rinvalid (void *opaque, target_phys_addr_t addr)
+{
+        struct fs_dma_ctrl *ctrl = opaque;
+        CPUState *env = ctrl->env;
+        cpu_abort(env, "Unsupported short access. reg=%x pc=%x.\n", 
+                  addr, env->pc);
+        return 0;
+}
+
+static uint32_t
+dma_readl (void *opaque, target_phys_addr_t addr)
+{
+        struct fs_dma_ctrl *ctrl = opaque;
+	int c;
+	uint32_t r = 0;
+
+	/* Make addr relative to this instances base.  */
+	c = fs_channel(ctrl->base, addr);
+        addr &= 0x1fff;
+	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=%x pc=%x\n",
+				 __func__, c, addr, env->pc));
+                        break;
+        }
+	return r;
+}
+
+static void
+dma_winvalid (void *opaque, target_phys_addr_t addr, uint32_t value)
+{
+        struct fs_dma_ctrl *ctrl = opaque;
+        CPUState *env = ctrl->env;
+        cpu_abort(env, "Unsupported short access. reg=%x pc=%x.\n", 
+                  addr, env->pc);
+}
+
+static void
+dma_writel (void *opaque, target_phys_addr_t addr, uint32_t value)
+{
+        struct fs_dma_ctrl *ctrl = opaque;
+	int c;
+
+        /* Make addr relative to this instances base.  */
+	c = fs_channel(ctrl->base, addr);
+        addr &= 0x1fff;
+        switch (addr)
+        {
+		case RW_DATA:
+			printf("RW_DATA=%x\n", value);			
+			break;
+
+		case RW_CFG:
+			ctrl->channels[c].regs[addr] = value;
+			break;
+		case RW_CMD:
+			/* continue.  */
+			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:
+			ctrl->channels[c].regs[addr] = value;
+			channel_stream_cmd(ctrl, c, value);
+			break;
+
+                default:
+                        D(printf ("%s c=%d %x %x pc=%x\n",
+				  __func__, c, addr, value, env->pc));
+                        break;
+        }
+}
+
+static CPUReadMemoryFunc *dma_read[] = {
+	&dma_rinvalid,
+	&dma_rinvalid,
+	&dma_readl,
+};
+
+static CPUWriteMemoryFunc *dma_write[] = {
+	&dma_winvalid,
+	&dma_winvalid,
+	&dma_writel,
+};
+
+void 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)
+		{
+			p++;
+			if (ctrl->channels[i].input)
+				channel_in_run(ctrl, i);
+			else
+				channel_out_run(ctrl, i);
+		}
+	}
+}
+
+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;
+}
+
+
+void *etraxfs_dmac_init(CPUState *env, 
+			target_phys_addr_t base, int nr_channels)
+{
+	struct fs_dma_ctrl *ctrl = NULL;
+	int i;
+
+	ctrl = qemu_mallocz(sizeof *ctrl);
+	if (!ctrl)
+		return NULL;
+
+	ctrl->base = base;
+	ctrl->env = env;
+	ctrl->nr_channels = nr_channels;
+	ctrl->channels = qemu_mallocz(sizeof ctrl->channels[0] * nr_channels);
+	if (!ctrl->channels)
+		goto err;
+
+	for (i = 0; i < nr_channels; i++)
+	{
+		ctrl->channels[i].regmap = cpu_register_io_memory(0,
+								  dma_read, 
+								  dma_write, 
+								  ctrl);
+		cpu_register_physical_memory (base + i * 0x2000,
+					      sizeof ctrl->channels[i].regs, 
+					      ctrl->channels[i].regmap);
+	}
+
+	return ctrl;
+  err:
+	qemu_free(ctrl->channels);
+	qemu_free(ctrl);
+	return NULL;
+}
diff --git a/hw/etraxfs_dma.h b/hw/etraxfs_dma.h
new file mode 100644
index 0000000000..27719aeae4
--- /dev/null
+++ b/hw/etraxfs_dma.h
@@ -0,0 +1,24 @@
+struct etraxfs_dma_client
+{
+	/* DMA controller. */
+	int channel;
+	void *ctrl;
+
+	/* client.  */
+	struct
+	{
+		int (*push)(void *opaque, unsigned char *buf, int len);
+		void (*pull)(void *opaque);
+		void *opaque;
+	} client;
+};
+
+void *etraxfs_dmac_init(CPUState *env, target_phys_addr_t base, 
+			int nr_channels);
+void etraxfs_dmac_connect(void *opaque, int channel, qemu_irq *line,
+			  int input);
+void etraxfs_dmac_connect_client(void *opaque, int c, 
+				 struct etraxfs_dma_client *cl);
+void etraxfs_dmac_run(void *opaque);
+int etraxfs_dmac_input(struct etraxfs_dma_client *client, 
+		       void *buf, int len, int eop);