introduce xlnx-dpdma

This is the implementation of the DPDMA.

Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
Reviewed-by: Alistair Francis <alistair.francis@xilinx.com>
Tested-By: Hyun Kwon <hyun.kwon@xilinx.com>
Message-id: 1465833014-21982-8-git-send-email-fred.konrad@greensocs.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

3 files changed, 880 insertions, 0 deletions

diff --git a/hw/dma/Makefile.objs b/hw/dma/Makefile.objs
index a1abbcf746..8b0823e593 100644
--- a/hw/dma/Makefile.objs
+++ b/hw/dma/Makefile.objs
@@ -8,6 +8,7 @@ common-obj-$(CONFIG_XILINX_AXI) += xilinx_axidma.o
 common-obj-$(CONFIG_ETRAXFS) += etraxfs_dma.o
 common-obj-$(CONFIG_STP2000) += sparc32_dma.o
 common-obj-$(CONFIG_SUN4M) += sun4m_iommu.o
+obj-$(CONFIG_XLNX_ZYNQMP) += xlnx_dpdma.o
 
 obj-$(CONFIG_OMAP) += omap_dma.o soc_dma.o
 obj-$(CONFIG_PXA2XX) += pxa2xx_dma.o
diff --git a/hw/dma/xlnx_dpdma.c b/hw/dma/xlnx_dpdma.c
new file mode 100644
index 0000000000..97a5da7fd2
--- /dev/null
+++ b/hw/dma/xlnx_dpdma.c
@@ -0,0 +1,794 @@
+/*
+ * xlnx_dpdma.c
+ *
+ *  Copyright (C) 2015 : GreenSocs Ltd
+ *      http://www.greensocs.com/ , email: info@greensocs.com
+ *
+ *  Developed by :
+ *  Frederic Konrad   <fred.konrad@greensocs.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/log.h"
+#include "hw/dma/xlnx_dpdma.h"
+
+#ifndef DEBUG_DPDMA
+#define DEBUG_DPDMA 0
+#endif
+
+#define DPRINTF(fmt, ...) do {                                                 \
+    if (DEBUG_DPDMA) {                                                         \
+        qemu_log("xlnx_dpdma: " fmt , ## __VA_ARGS__);                         \
+    }                                                                          \
+} while (0);
+
+/*
+ * Registers offset for DPDMA.
+ */
+#define DPDMA_ERR_CTRL                        (0x0000)
+#define DPDMA_ISR                             (0x0004 >> 2)
+#define DPDMA_IMR                             (0x0008 >> 2)
+#define DPDMA_IEN                             (0x000C >> 2)
+#define DPDMA_IDS                             (0x0010 >> 2)
+#define DPDMA_EISR                            (0x0014 >> 2)
+#define DPDMA_EIMR                            (0x0018 >> 2)
+#define DPDMA_EIEN                            (0x001C >> 2)
+#define DPDMA_EIDS                            (0x0020 >> 2)
+#define DPDMA_CNTL                            (0x0100 >> 2)
+
+#define DPDMA_GBL                             (0x0104 >> 2)
+#define DPDMA_GBL_TRG_CH(n)                   (1 << n)
+#define DPDMA_GBL_RTRG_CH(n)                  (1 << 6 << n)
+
+#define DPDMA_ALC0_CNTL                       (0x0108 >> 2)
+#define DPDMA_ALC0_STATUS                     (0x010C >> 2)
+#define DPDMA_ALC0_MAX                        (0x0110 >> 2)
+#define DPDMA_ALC0_MIN                        (0x0114 >> 2)
+#define DPDMA_ALC0_ACC                        (0x0118 >> 2)
+#define DPDMA_ALC0_ACC_TRAN                   (0x011C >> 2)
+#define DPDMA_ALC1_CNTL                       (0x0120 >> 2)
+#define DPDMA_ALC1_STATUS                     (0x0124 >> 2)
+#define DPDMA_ALC1_MAX                        (0x0128 >> 2)
+#define DPDMA_ALC1_MIN                        (0x012C >> 2)
+#define DPDMA_ALC1_ACC                        (0x0130 >> 2)
+#define DPDMA_ALC1_ACC_TRAN                   (0x0134 >> 2)
+
+#define DPDMA_DSCR_STRT_ADDRE_CH(n)           ((0x0200 + n * 0x100) >> 2)
+#define DPDMA_DSCR_STRT_ADDR_CH(n)            ((0x0204 + n * 0x100) >> 2)
+#define DPDMA_DSCR_NEXT_ADDRE_CH(n)           ((0x0208 + n * 0x100) >> 2)
+#define DPDMA_DSCR_NEXT_ADDR_CH(n)            ((0x020C + n * 0x100) >> 2)
+#define DPDMA_PYLD_CUR_ADDRE_CH(n)            ((0x0210 + n * 0x100) >> 2)
+#define DPDMA_PYLD_CUR_ADDR_CH(n)             ((0x0214 + n * 0x100) >> 2)
+
+#define DPDMA_CNTL_CH(n)                      ((0x0218 + n * 0x100) >> 2)
+#define DPDMA_CNTL_CH_EN                      (1)
+#define DPDMA_CNTL_CH_PAUSED                  (1 << 1)
+
+#define DPDMA_STATUS_CH(n)                    ((0x021C + n * 0x100) >> 2)
+#define DPDMA_STATUS_BURST_TYPE               (1 << 4)
+#define DPDMA_STATUS_MODE                     (1 << 5)
+#define DPDMA_STATUS_EN_CRC                   (1 << 6)
+#define DPDMA_STATUS_LAST_DSCR                (1 << 7)
+#define DPDMA_STATUS_LDSCR_FRAME              (1 << 8)
+#define DPDMA_STATUS_IGNR_DONE                (1 << 9)
+#define DPDMA_STATUS_DSCR_DONE                (1 << 10)
+#define DPDMA_STATUS_EN_DSCR_UP               (1 << 11)
+#define DPDMA_STATUS_EN_DSCR_INTR             (1 << 12)
+#define DPDMA_STATUS_PREAMBLE_OFF             (13)
+
+#define DPDMA_VDO_CH(n)                       ((0x0220 + n * 0x100) >> 2)
+#define DPDMA_PYLD_SZ_CH(n)                   ((0x0224 + n * 0x100) >> 2)
+#define DPDMA_DSCR_ID_CH(n)                   ((0x0228 + n * 0x100) >> 2)
+
+/*
+ * Descriptor control field.
+ */
+#define CONTROL_PREAMBLE_VALUE                0xA5
+
+#define DSCR_CTRL_PREAMBLE                    0xFF
+#define DSCR_CTRL_EN_DSCR_DONE_INTR           (1 << 8)
+#define DSCR_CTRL_EN_DSCR_UPDATE              (1 << 9)
+#define DSCR_CTRL_IGNORE_DONE                 (1 << 10)
+#define DSCR_CTRL_AXI_BURST_TYPE              (1 << 11)
+#define DSCR_CTRL_AXCACHE                     (0x0F << 12)
+#define DSCR_CTRL_AXPROT                      (0x2 << 16)
+#define DSCR_CTRL_DESCRIPTOR_MODE             (1 << 18)
+#define DSCR_CTRL_LAST_DESCRIPTOR             (1 << 19)
+#define DSCR_CTRL_ENABLE_CRC                  (1 << 20)
+#define DSCR_CTRL_LAST_DESCRIPTOR_OF_FRAME    (1 << 21)
+
+/*
+ * Descriptor timestamp field.
+ */
+#define STATUS_DONE                           (1 << 31)
+
+#define DPDMA_FRAG_MAX_SZ                     (4096)
+
+enum DPDMABurstType {
+    DPDMA_INCR = 0,
+    DPDMA_FIXED = 1
+};
+
+enum DPDMAMode {
+    DPDMA_CONTIGOUS = 0,
+    DPDMA_FRAGMENTED = 1
+};
+
+struct DPDMADescriptor {
+    uint32_t control;
+    uint32_t descriptor_id;
+    /* transfer size in byte. */
+    uint32_t xfer_size;
+    uint32_t line_size_stride;
+    uint32_t timestamp_lsb;
+    uint32_t timestamp_msb;
+    /* contains extension for both descriptor and source. */
+    uint32_t address_extension;
+    uint32_t next_descriptor;
+    uint32_t source_address;
+    uint32_t address_extension_23;
+    uint32_t address_extension_45;
+    uint32_t source_address2;
+    uint32_t source_address3;
+    uint32_t source_address4;
+    uint32_t source_address5;
+    uint32_t crc;
+};
+
+typedef enum DPDMABurstType DPDMABurstType;
+typedef enum DPDMAMode DPDMAMode;
+typedef struct DPDMADescriptor DPDMADescriptor;
+
+static bool xlnx_dpdma_desc_is_last(DPDMADescriptor *desc)
+{
+    return ((desc->control & DSCR_CTRL_LAST_DESCRIPTOR) != 0);
+}
+
+static bool xlnx_dpdma_desc_is_last_of_frame(DPDMADescriptor *desc)
+{
+    return ((desc->control & DSCR_CTRL_LAST_DESCRIPTOR_OF_FRAME) != 0);
+}
+
+static uint64_t xlnx_dpdma_desc_get_source_address(DPDMADescriptor *desc,
+                                                     uint8_t frag)
+{
+    uint64_t addr = 0;
+    assert(frag < 5);
+
+    switch (frag) {
+    case 0:
+        addr = desc->source_address
+            + (extract32(desc->address_extension, 16, 12) << 20);
+        break;
+    case 1:
+        addr = desc->source_address2
+            + (extract32(desc->address_extension_23, 0, 12) << 8);
+        break;
+    case 2:
+        addr = desc->source_address3
+            + (extract32(desc->address_extension_23, 16, 12) << 20);
+        break;
+    case 3:
+        addr = desc->source_address4
+            + (extract32(desc->address_extension_45, 0, 12) << 8);
+        break;
+    case 4:
+        addr = desc->source_address5
+            + (extract32(desc->address_extension_45, 16, 12) << 20);
+        break;
+    default:
+        addr = 0;
+        break;
+    }
+
+    return addr;
+}
+
+static uint32_t xlnx_dpdma_desc_get_transfer_size(DPDMADescriptor *desc)
+{
+    return desc->xfer_size;
+}
+
+static uint32_t xlnx_dpdma_desc_get_line_size(DPDMADescriptor *desc)
+{
+    return extract32(desc->line_size_stride, 0, 18);
+}
+
+static uint32_t xlnx_dpdma_desc_get_line_stride(DPDMADescriptor *desc)
+{
+    return extract32(desc->line_size_stride, 18, 14) * 16;
+}
+
+static inline bool xlnx_dpdma_desc_crc_enabled(DPDMADescriptor *desc)
+{
+    return (desc->control & DSCR_CTRL_ENABLE_CRC) != 0;
+}
+
+static inline bool xlnx_dpdma_desc_check_crc(DPDMADescriptor *desc)
+{
+    uint32_t *p = (uint32_t *)desc;
+    uint32_t crc = 0;
+    uint8_t i;
+
+    /*
+     * CRC is calculated on the whole descriptor except the last 32bits word
+     * using 32bits addition.
+     */
+    for (i = 0; i < 15; i++) {
+        crc += p[i];
+    }
+
+    return crc == desc->crc;
+}
+
+static inline bool xlnx_dpdma_desc_completion_interrupt(DPDMADescriptor *desc)
+{
+    return (desc->control & DSCR_CTRL_EN_DSCR_DONE_INTR) != 0;
+}
+
+static inline bool xlnx_dpdma_desc_is_valid(DPDMADescriptor *desc)
+{
+    return (desc->control & DSCR_CTRL_PREAMBLE) == CONTROL_PREAMBLE_VALUE;
+}
+
+static inline bool xlnx_dpdma_desc_is_contiguous(DPDMADescriptor *desc)
+{
+    return (desc->control & DSCR_CTRL_DESCRIPTOR_MODE) == 0;
+}
+
+static inline bool xlnx_dpdma_desc_update_enabled(DPDMADescriptor *desc)
+{
+    return (desc->control & DSCR_CTRL_EN_DSCR_UPDATE) != 0;
+}
+
+static inline void xlnx_dpdma_desc_set_done(DPDMADescriptor *desc)
+{
+    desc->timestamp_msb |= STATUS_DONE;
+}
+
+static inline bool xlnx_dpdma_desc_is_already_done(DPDMADescriptor *desc)
+{
+    return (desc->timestamp_msb & STATUS_DONE) != 0;
+}
+
+static inline bool xlnx_dpdma_desc_ignore_done_bit(DPDMADescriptor *desc)
+{
+    return (desc->control & DSCR_CTRL_IGNORE_DONE) != 0;
+}
+
+static const VMStateDescription vmstate_xlnx_dpdma = {
+    .name = TYPE_XLNX_DPDMA,
+    .version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32_ARRAY(registers, XlnxDPDMAState,
+                             XLNX_DPDMA_REG_ARRAY_SIZE),
+        VMSTATE_BOOL_ARRAY(operation_finished, XlnxDPDMAState, 6),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void xlnx_dpdma_update_irq(XlnxDPDMAState *s)
+{
+    bool flags;
+
+    flags = ((s->registers[DPDMA_ISR] & (~s->registers[DPDMA_IMR]))
+          || (s->registers[DPDMA_EISR] & (~s->registers[DPDMA_EIMR])));
+    qemu_set_irq(s->irq, flags);
+}
+
+static uint64_t xlnx_dpdma_descriptor_start_address(XlnxDPDMAState *s,
+                                                      uint8_t channel)
+{
+    return (s->registers[DPDMA_DSCR_STRT_ADDRE_CH(channel)] << 16)
+          + s->registers[DPDMA_DSCR_STRT_ADDR_CH(channel)];
+}
+
+static uint64_t xlnx_dpdma_descriptor_next_address(XlnxDPDMAState *s,
+                                                     uint8_t channel)
+{
+    return ((uint64_t)s->registers[DPDMA_DSCR_NEXT_ADDRE_CH(channel)] << 32)
+           + s->registers[DPDMA_DSCR_NEXT_ADDR_CH(channel)];
+}
+
+static inline void xlnx_dpdma_set_desc_next_address(XlnxDPDMAState *s,
+                                                      uint8_t channel,
+                                                      uint64_t addr)
+{
+    s->registers[DPDMA_DSCR_NEXT_ADDRE_CH(channel)] = extract64(addr, 32, 32);
+    s->registers[DPDMA_DSCR_NEXT_ADDR_CH(channel)] = extract64(addr, 0, 32);
+}
+
+static bool xlnx_dpdma_is_channel_enabled(XlnxDPDMAState *s,
+                                            uint8_t channel)
+{
+    return (s->registers[DPDMA_CNTL_CH(channel)] & DPDMA_CNTL_CH_EN) != 0;
+}
+
+static bool xlnx_dpdma_is_channel_paused(XlnxDPDMAState *s,
+                                           uint8_t channel)
+{
+    return (s->registers[DPDMA_CNTL_CH(channel)] & DPDMA_CNTL_CH_PAUSED) != 0;
+}
+
+static inline bool xlnx_dpdma_is_channel_retriggered(XlnxDPDMAState *s,
+                                                       uint8_t channel)
+{
+    /* Clear the retriggered bit after reading it. */
+    bool channel_is_retriggered = s->registers[DPDMA_GBL]
+                                & DPDMA_GBL_RTRG_CH(channel);
+    s->registers[DPDMA_GBL] &= ~DPDMA_GBL_RTRG_CH(channel);
+    return channel_is_retriggered;
+}
+
+static inline bool xlnx_dpdma_is_channel_triggered(XlnxDPDMAState *s,
+                                                     uint8_t channel)
+{
+    return s->registers[DPDMA_GBL] & DPDMA_GBL_TRG_CH(channel);
+}
+
+static void xlnx_dpdma_update_desc_info(XlnxDPDMAState *s, uint8_t channel,
+                                          DPDMADescriptor *desc)
+{
+    s->registers[DPDMA_DSCR_NEXT_ADDRE_CH(channel)] =
+                                extract32(desc->address_extension, 0, 16);
+    s->registers[DPDMA_DSCR_NEXT_ADDR_CH(channel)] = desc->next_descriptor;
+    s->registers[DPDMA_PYLD_CUR_ADDRE_CH(channel)] =
+                                extract32(desc->address_extension, 16, 16);
+    s->registers[DPDMA_PYLD_CUR_ADDR_CH(channel)] = desc->source_address;
+    s->registers[DPDMA_VDO_CH(channel)] =
+                                extract32(desc->line_size_stride, 18, 14)
+                                + (extract32(desc->line_size_stride, 0, 18)
+                                  << 14);
+    s->registers[DPDMA_PYLD_SZ_CH(channel)] = desc->xfer_size;
+    s->registers[DPDMA_DSCR_ID_CH(channel)] = desc->descriptor_id;
+
+    /* Compute the status register with the descriptor information. */
+    s->registers[DPDMA_STATUS_CH(channel)] =
+                                extract32(desc->control, 0, 8) << 13;
+    if ((desc->control & DSCR_CTRL_EN_DSCR_DONE_INTR) != 0) {
+        s->registers[DPDMA_STATUS_CH(channel)] |= DPDMA_STATUS_EN_DSCR_INTR;
+    }
+    if ((desc->control & DSCR_CTRL_EN_DSCR_UPDATE) != 0) {
+        s->registers[DPDMA_STATUS_CH(channel)] |= DPDMA_STATUS_EN_DSCR_UP;
+    }
+    if ((desc->timestamp_msb & STATUS_DONE) != 0) {
+        s->registers[DPDMA_STATUS_CH(channel)] |= DPDMA_STATUS_DSCR_DONE;
+    }
+    if ((desc->control & DSCR_CTRL_IGNORE_DONE) != 0) {
+        s->registers[DPDMA_STATUS_CH(channel)] |= DPDMA_STATUS_IGNR_DONE;
+    }
+    if ((desc->control & DSCR_CTRL_LAST_DESCRIPTOR_OF_FRAME) != 0) {
+        s->registers[DPDMA_STATUS_CH(channel)] |= DPDMA_STATUS_LDSCR_FRAME;
+    }
+    if ((desc->control & DSCR_CTRL_LAST_DESCRIPTOR) != 0) {
+        s->registers[DPDMA_STATUS_CH(channel)] |= DPDMA_STATUS_LAST_DSCR;
+    }
+    if ((desc->control & DSCR_CTRL_ENABLE_CRC) != 0) {
+        s->registers[DPDMA_STATUS_CH(channel)] |= DPDMA_STATUS_EN_CRC;
+    }
+    if ((desc->control & DSCR_CTRL_DESCRIPTOR_MODE) != 0) {
+        s->registers[DPDMA_STATUS_CH(channel)] |= DPDMA_STATUS_MODE;
+    }
+    if ((desc->control & DSCR_CTRL_AXI_BURST_TYPE) != 0) {
+        s->registers[DPDMA_STATUS_CH(channel)] |= DPDMA_STATUS_BURST_TYPE;
+    }
+}
+
+static void xlnx_dpdma_dump_descriptor(DPDMADescriptor *desc)
+{
+    if (DEBUG_DPDMA) {
+        qemu_log("DUMP DESCRIPTOR:\n");
+        qemu_hexdump((char *)desc, stdout, "", sizeof(DPDMADescriptor));
+    }
+}
+
+static uint64_t xlnx_dpdma_read(void *opaque, hwaddr offset,
+                                unsigned size)
+{
+    XlnxDPDMAState *s = XLNX_DPDMA(opaque);
+
+    DPRINTF("read @%" HWADDR_PRIx "\n", offset);
+    offset = offset >> 2;
+
+    switch (offset) {
+    /*
+     * Trying to read a write only register.
+     */
+    case DPDMA_GBL:
+        return 0;
+    default:
+        assert(offset <= (0xFFC >> 2));
+        return s->registers[offset];
+    }
+    return 0;
+}
+
+static void xlnx_dpdma_write(void *opaque, hwaddr offset,
+                               uint64_t value, unsigned size)
+{
+    XlnxDPDMAState *s = XLNX_DPDMA(opaque);
+
+    DPRINTF("write @%" HWADDR_PRIx " = %" PRIx64 "\n", offset, value);
+    offset = offset >> 2;
+
+    switch (offset) {
+    case DPDMA_ISR:
+        s->registers[DPDMA_ISR] &= ~value;
+        xlnx_dpdma_update_irq(s);
+        break;
+    case DPDMA_IEN:
+        s->registers[DPDMA_IMR] &= ~value;
+        break;
+    case DPDMA_IDS:
+        s->registers[DPDMA_IMR] |= value;
+        break;
+    case DPDMA_EISR:
+        s->registers[DPDMA_EISR] &= ~value;
+        xlnx_dpdma_update_irq(s);
+        break;
+    case DPDMA_EIEN:
+        s->registers[DPDMA_EIMR] &= ~value;
+        break;
+    case DPDMA_EIDS:
+        s->registers[DPDMA_EIMR] |= value;
+        break;
+    case DPDMA_IMR:
+    case DPDMA_EIMR:
+    case DPDMA_DSCR_NEXT_ADDRE_CH(0):
+    case DPDMA_DSCR_NEXT_ADDRE_CH(1):
+    case DPDMA_DSCR_NEXT_ADDRE_CH(2):
+    case DPDMA_DSCR_NEXT_ADDRE_CH(3):
+    case DPDMA_DSCR_NEXT_ADDRE_CH(4):
+    case DPDMA_DSCR_NEXT_ADDRE_CH(5):
+    case DPDMA_DSCR_NEXT_ADDR_CH(0):
+    case DPDMA_DSCR_NEXT_ADDR_CH(1):
+    case DPDMA_DSCR_NEXT_ADDR_CH(2):
+    case DPDMA_DSCR_NEXT_ADDR_CH(3):
+    case DPDMA_DSCR_NEXT_ADDR_CH(4):
+    case DPDMA_DSCR_NEXT_ADDR_CH(5):
+    case DPDMA_PYLD_CUR_ADDRE_CH(0):
+    case DPDMA_PYLD_CUR_ADDRE_CH(1):
+    case DPDMA_PYLD_CUR_ADDRE_CH(2):
+    case DPDMA_PYLD_CUR_ADDRE_CH(3):
+    case DPDMA_PYLD_CUR_ADDRE_CH(4):
+    case DPDMA_PYLD_CUR_ADDRE_CH(5):
+    case DPDMA_PYLD_CUR_ADDR_CH(0):
+    case DPDMA_PYLD_CUR_ADDR_CH(1):
+    case DPDMA_PYLD_CUR_ADDR_CH(2):
+    case DPDMA_PYLD_CUR_ADDR_CH(3):
+    case DPDMA_PYLD_CUR_ADDR_CH(4):
+    case DPDMA_PYLD_CUR_ADDR_CH(5):
+    case DPDMA_STATUS_CH(0):
+    case DPDMA_STATUS_CH(1):
+    case DPDMA_STATUS_CH(2):
+    case DPDMA_STATUS_CH(3):
+    case DPDMA_STATUS_CH(4):
+    case DPDMA_STATUS_CH(5):
+    case DPDMA_VDO_CH(0):
+    case DPDMA_VDO_CH(1):
+    case DPDMA_VDO_CH(2):
+    case DPDMA_VDO_CH(3):
+    case DPDMA_VDO_CH(4):
+    case DPDMA_VDO_CH(5):
+    case DPDMA_PYLD_SZ_CH(0):
+    case DPDMA_PYLD_SZ_CH(1):
+    case DPDMA_PYLD_SZ_CH(2):
+    case DPDMA_PYLD_SZ_CH(3):
+    case DPDMA_PYLD_SZ_CH(4):
+    case DPDMA_PYLD_SZ_CH(5):
+    case DPDMA_DSCR_ID_CH(0):
+    case DPDMA_DSCR_ID_CH(1):
+    case DPDMA_DSCR_ID_CH(2):
+    case DPDMA_DSCR_ID_CH(3):
+    case DPDMA_DSCR_ID_CH(4):
+    case DPDMA_DSCR_ID_CH(5):
+        /*
+         * Trying to write to a read only register..
+         */
+        break;
+    case DPDMA_GBL:
+        /*
+         * This is a write only register so it's read as zero in the read
+         * callback.
+         * We store the value anyway so we can know if the channel is
+         * enabled.
+         */
+        s->registers[offset] |= value & 0x00000FFF;
+        break;
+    case DPDMA_DSCR_STRT_ADDRE_CH(0):
+    case DPDMA_DSCR_STRT_ADDRE_CH(1):
+    case DPDMA_DSCR_STRT_ADDRE_CH(2):
+    case DPDMA_DSCR_STRT_ADDRE_CH(3):
+    case DPDMA_DSCR_STRT_ADDRE_CH(4):
+    case DPDMA_DSCR_STRT_ADDRE_CH(5):
+        value &= 0x0000FFFF;
+        s->registers[offset] = value;
+        break;
+    case DPDMA_CNTL_CH(0):
+        s->registers[DPDMA_GBL] &= ~DPDMA_GBL_TRG_CH(0);
+        value &= 0x3FFFFFFF;
+        s->registers[offset] = value;
+        break;
+    case DPDMA_CNTL_CH(1):
+        s->registers[DPDMA_GBL] &= ~DPDMA_GBL_TRG_CH(1);
+        value &= 0x3FFFFFFF;
+        s->registers[offset] = value;
+        break;
+    case DPDMA_CNTL_CH(2):
+        s->registers[DPDMA_GBL] &= ~DPDMA_GBL_TRG_CH(2);
+        value &= 0x3FFFFFFF;
+        s->registers[offset] = value;
+        break;
+    case DPDMA_CNTL_CH(3):
+        s->registers[DPDMA_GBL] &= ~DPDMA_GBL_TRG_CH(3);
+        value &= 0x3FFFFFFF;
+        s->registers[offset] = value;
+        break;
+    case DPDMA_CNTL_CH(4):
+        s->registers[DPDMA_GBL] &= ~DPDMA_GBL_TRG_CH(4);
+        value &= 0x3FFFFFFF;
+        s->registers[offset] = value;
+        break;
+    case DPDMA_CNTL_CH(5):
+        s->registers[DPDMA_GBL] &= ~DPDMA_GBL_TRG_CH(5);
+        value &= 0x3FFFFFFF;
+        s->registers[offset] = value;
+        break;
+    default:
+        assert(offset <= (0xFFC >> 2));
+        s->registers[offset] = value;
+        break;
+    }
+}
+
+static const MemoryRegionOps dma_ops = {
+    .read = xlnx_dpdma_read,
+    .write = xlnx_dpdma_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+    .valid = {
+        .min_access_size = 4,
+        .max_access_size = 4,
+    },
+    .impl = {
+        .min_access_size = 4,
+        .max_access_size = 4,
+    },
+};
+
+static void xlnx_dpdma_init(Object *obj)
+{
+    SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
+    XlnxDPDMAState *s = XLNX_DPDMA(obj);
+
+    memory_region_init_io(&s->iomem, obj, &dma_ops, s,
+                          TYPE_XLNX_DPDMA, 0x1000);
+    sysbus_init_mmio(sbd, &s->iomem);
+    sysbus_init_irq(sbd, &s->irq);
+}
+
+static void xlnx_dpdma_reset(DeviceState *dev)
+{
+    XlnxDPDMAState *s = XLNX_DPDMA(dev);
+    size_t i;
+
+    memset(s->registers, 0, sizeof(s->registers));
+    s->registers[DPDMA_IMR] =  0x07FFFFFF;
+    s->registers[DPDMA_EIMR] = 0xFFFFFFFF;
+    s->registers[DPDMA_ALC0_MIN] = 0x0000FFFF;
+    s->registers[DPDMA_ALC1_MIN] = 0x0000FFFF;
+
+    for (i = 0; i < 6; i++) {
+        s->data[i] = NULL;
+        s->operation_finished[i] = true;
+    }
+}
+
+static void xlnx_dpdma_class_init(ObjectClass *oc, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+
+    dc->vmsd = &vmstate_xlnx_dpdma;
+    dc->reset = xlnx_dpdma_reset;
+}
+
+static const TypeInfo xlnx_dpdma_info = {
+    .name          = TYPE_XLNX_DPDMA,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(XlnxDPDMAState),
+    .instance_init = xlnx_dpdma_init,
+    .class_init    = xlnx_dpdma_class_init,
+};
+
+static void xlnx_dpdma_register_types(void)
+{
+    type_register_static(&xlnx_dpdma_info);
+}
+
+size_t xlnx_dpdma_start_operation(XlnxDPDMAState *s, uint8_t channel,
+                                    bool one_desc)
+{
+    uint64_t desc_addr;
+    uint64_t source_addr[6];
+    DPDMADescriptor desc;
+    bool done = false;
+    size_t ptr = 0;
+
+    assert(channel <= 5);
+
+    DPRINTF("start dpdma channel 0x%" PRIX8 "\n", channel);
+
+    if (!xlnx_dpdma_is_channel_triggered(s, channel)) {
+        DPRINTF("Channel isn't triggered..\n");
+        return 0;
+    }
+
+    if (!xlnx_dpdma_is_channel_enabled(s, channel)) {
+        DPRINTF("Channel isn't enabled..\n");
+        return 0;
+    }
+
+    if (xlnx_dpdma_is_channel_paused(s, channel)) {
+        DPRINTF("Channel is paused..\n");
+        return 0;
+    }
+
+    do {
+        if ((s->operation_finished[channel])
+          || xlnx_dpdma_is_channel_retriggered(s, channel)) {
+            desc_addr = xlnx_dpdma_descriptor_start_address(s, channel);
+            s->operation_finished[channel] = false;
+        } else {
+            desc_addr = xlnx_dpdma_descriptor_next_address(s, channel);
+        }
+
+        if (dma_memory_read(&address_space_memory, desc_addr, &desc,
+                            sizeof(DPDMADescriptor))) {
+            s->registers[DPDMA_EISR] |= ((1 << 1) << channel);
+            xlnx_dpdma_update_irq(s);
+            s->operation_finished[channel] = true;
+            DPRINTF("Can't get the descriptor.\n");
+            break;
+        }
+
+        xlnx_dpdma_update_desc_info(s, channel, &desc);
+
+#ifdef DEBUG_DPDMA
+        xlnx_dpdma_dump_descriptor(&desc);
+#endif
+
+        DPRINTF("location of the descriptor: %" PRIx64 "\n", desc_addr);
+        if (!xlnx_dpdma_desc_is_valid(&desc)) {
+            s->registers[DPDMA_EISR] |= ((1 << 7) << channel);
+            xlnx_dpdma_update_irq(s);
+            s->operation_finished[channel] = true;
+            DPRINTF("Invalid descriptor..\n");
+            break;
+        }
+
+        if (xlnx_dpdma_desc_crc_enabled(&desc)
+            && !xlnx_dpdma_desc_check_crc(&desc)) {
+            s->registers[DPDMA_EISR] |= ((1 << 13) << channel);
+            xlnx_dpdma_update_irq(s);
+            s->operation_finished[channel] = true;
+            DPRINTF("Bad CRC for descriptor..\n");
+            break;
+        }
+
+        if (xlnx_dpdma_desc_is_already_done(&desc)
+            && !xlnx_dpdma_desc_ignore_done_bit(&desc)) {
+            /* We are trying to process an already processed descriptor. */
+            s->registers[DPDMA_EISR] |= ((1 << 25) << channel);
+            xlnx_dpdma_update_irq(s);
+            s->operation_finished[channel] = true;
+            DPRINTF("Already processed descriptor..\n");
+            break;
+        }
+
+        done = xlnx_dpdma_desc_is_last(&desc)
+             || xlnx_dpdma_desc_is_last_of_frame(&desc);
+
+        s->operation_finished[channel] = done;
+        if (s->data[channel]) {
+            int64_t transfer_len = xlnx_dpdma_desc_get_transfer_size(&desc);
+            uint32_t line_size = xlnx_dpdma_desc_get_line_size(&desc);
+            uint32_t line_stride = xlnx_dpdma_desc_get_line_stride(&desc);
+            if (xlnx_dpdma_desc_is_contiguous(&desc)) {
+                source_addr[0] = xlnx_dpdma_desc_get_source_address(&desc, 0);
+                while (transfer_len != 0) {
+                    if (dma_memory_read(&address_space_memory,
+                                        source_addr[0],
+                                        &s->data[channel][ptr],
+                                        line_size)) {
+                        s->registers[DPDMA_ISR] |= ((1 << 12) << channel);
+                        xlnx_dpdma_update_irq(s);
+                        DPRINTF("Can't get data.\n");
+                        break;
+                    }
+                    ptr += line_size;
+                    transfer_len -= line_size;
+                    source_addr[0] += line_stride;
+                }
+            } else {
+                DPRINTF("Source address:\n");
+                int frag;
+                for (frag = 0; frag < 5; frag++) {
+                    source_addr[frag] =
+                          xlnx_dpdma_desc_get_source_address(&desc, frag);
+                    DPRINTF("Fragment %u: %" PRIx64 "\n", frag + 1,
+                            source_addr[frag]);
+                }
+
+                frag = 0;
+                while ((transfer_len < 0) && (frag < 5)) {
+                    size_t fragment_len = DPDMA_FRAG_MAX_SZ
+                                    - (source_addr[frag] % DPDMA_FRAG_MAX_SZ);
+
+                    if (dma_memory_read(&address_space_memory,
+                                        source_addr[frag],
+                                        &(s->data[channel][ptr]),
+                                        fragment_len)) {
+                        s->registers[DPDMA_ISR] |= ((1 << 12) << channel);
+                        xlnx_dpdma_update_irq(s);
+                        DPRINTF("Can't get data.\n");
+                        break;
+                    }
+                    ptr += fragment_len;
+                    transfer_len -= fragment_len;
+                    frag += 1;
+                }
+            }
+        }
+
+        if (xlnx_dpdma_desc_update_enabled(&desc)) {
+            /* The descriptor need to be updated when it's completed. */
+            DPRINTF("update the descriptor with the done flag set.\n");
+            xlnx_dpdma_desc_set_done(&desc);
+            dma_memory_write(&address_space_memory, desc_addr, &desc,
+                             sizeof(DPDMADescriptor));
+        }
+
+        if (xlnx_dpdma_desc_completion_interrupt(&desc)) {
+            DPRINTF("completion interrupt enabled!\n");
+            s->registers[DPDMA_ISR] |= (1 << channel);
+            xlnx_dpdma_update_irq(s);
+        }
+
+    } while (!done && !one_desc);
+
+    return ptr;
+}
+
+void xlnx_dpdma_set_host_data_location(XlnxDPDMAState *s, uint8_t channel,
+                                         void *p)
+{
+    if (!s) {
+        qemu_log_mask(LOG_UNIMP, "DPDMA client not attached to valid DPDMA"
+                      " instance\n");
+        return;
+    }
+
+    assert(channel <= 5);
+    s->data[channel] = p;
+}
+
+void xlnx_dpdma_trigger_vsync_irq(XlnxDPDMAState *s)
+{
+    s->registers[DPDMA_ISR] |= (1 << 27);
+    xlnx_dpdma_update_irq(s);
+}
+
+type_init(xlnx_dpdma_register_types)
diff --git a/include/hw/dma/xlnx_dpdma.h b/include/hw/dma/xlnx_dpdma.h
new file mode 100644
index 0000000000..ae571a0b2f
--- /dev/null
+++ b/include/hw/dma/xlnx_dpdma.h
@@ -0,0 +1,85 @@
+/*
+ * xlnx_dpdma.h
+ *
+ *  Copyright (C) 2015 : GreenSocs Ltd
+ *      http://www.greensocs.com/ , email: info@greensocs.com
+ *
+ *  Developed by :
+ *  Frederic Konrad   <fred.konrad@greensocs.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef XLNX_DPDMA_H
+#define XLNX_DPDMA_H
+
+#include "hw/sysbus.h"
+#include "ui/console.h"
+#include "sysemu/dma.h"
+
+#define XLNX_DPDMA_REG_ARRAY_SIZE (0x1000 >> 2)
+
+struct XlnxDPDMAState {
+    /*< private >*/
+    SysBusDevice parent_obj;
+    /*< public >*/
+    MemoryRegion iomem;
+    uint32_t registers[XLNX_DPDMA_REG_ARRAY_SIZE];
+    uint8_t *data[6];
+    bool operation_finished[6];
+    qemu_irq irq;
+};
+
+typedef struct XlnxDPDMAState XlnxDPDMAState;
+
+#define TYPE_XLNX_DPDMA "xlnx.dpdma"
+#define XLNX_DPDMA(obj) OBJECT_CHECK(XlnxDPDMAState, (obj), TYPE_XLNX_DPDMA)
+
+/*
+ * xlnx_dpdma_start_operation: Start the operation on the specified channel. The
+ *                             DPDMA gets the current descriptor and retrieves
+ *                             data to the buffer specified by
+ *                             dpdma_set_host_data_location().
+ *
+ * Returns The number of bytes transfered by the DPDMA or 0 if an error occured.
+ *
+ * @s The DPDMA state.
+ * @channel The channel to start.
+ */
+size_t xlnx_dpdma_start_operation(XlnxDPDMAState *s, uint8_t channel,
+                                  bool one_desc);
+
+/*
+ * xlnx_dpdma_set_host_data_location: Set the location in the host memory where
+ *                                    to store the data out from the dma
+ *                                    channel.
+ *
+ * @s The DPDMA state.
+ * @channel The channel associated to the pointer.
+ * @p The buffer where to store the data.
+ */
+/* XXX: add a maximum size arg and send an interrupt in case of overflow. */
+void xlnx_dpdma_set_host_data_location(XlnxDPDMAState *s, uint8_t channel,
+                                       void *p);
+
+/*
+ * xlnx_dpdma_trigger_vsync_irq: Trigger a VSYNC IRQ when the display is
+ *                               updated.
+ *
+ * @s The DPDMA state.
+ */
+void xlnx_dpdma_trigger_vsync_irq(XlnxDPDMAState *s);
+
+#endif /* !XLNX_DPDMA_H */