bcm2835_dma: add emulation of Raspberry Pi DMA controller

At present, all DMA transfers complete inline (so a looping descriptor
queue will lock up the device). We also do not model pause/abort,
arbitrarion/priority, or debug features.

Signed-off-by: Grégory ESTRADE <gregory.estrade@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Andrew Baumann <Andrew.Baumann@microsoft.com>
Message-id: 1457467526-8840-6-git-send-email-Andrew.Baumann@microsoft.com
[AB: implement 2D mode, cleanup/refactoring for upstream submission]
Signed-off-by: Andrew Baumann <Andrew.Baumann@microsoft.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

2 files changed, 49 insertions, 0 deletions

diff --git a/include/hw/arm/bcm2835_peripherals.h b/include/hw/arm/bcm2835_peripherals.h
index e19d360..e12ae37 100644
--- a/include/hw/arm/bcm2835_peripherals.h
+++ b/include/hw/arm/bcm2835_peripherals.h
@@ -16,6 +16,7 @@
 #include "hw/sysbus.h"
 #include "hw/char/bcm2835_aux.h"
 #include "hw/display/bcm2835_fb.h"
+#include "hw/dma/bcm2835_dma.h"
 #include "hw/intc/bcm2835_ic.h"
 #include "hw/misc/bcm2835_property.h"
 #include "hw/misc/bcm2835_mbox.h"
@@ -37,6 +38,7 @@ typedef struct BCM2835PeripheralState {
     SysBusDevice *uart0;
     BCM2835AuxState aux;
     BCM2835FBState fb;
+    BCM2835DMAState dma;
     BCM2835ICState ic;
     BCM2835PropertyState property;
     BCM2835MboxState mboxes;
diff --git a/include/hw/dma/bcm2835_dma.h b/include/hw/dma/bcm2835_dma.h
new file mode 100644
index 0000000..75312e2
--- /dev/null
+++ b/include/hw/dma/bcm2835_dma.h
@@ -0,0 +1,47 @@
+/*
+ * Raspberry Pi emulation (c) 2012 Gregory Estrade
+ * This code is licensed under the GNU GPLv2 and later.
+ */
+
+#ifndef BCM2835_DMA_H
+#define BCM2835_DMA_H
+
+#include "qemu-common.h"
+#include "exec/address-spaces.h"
+#include "hw/sysbus.h"
+
+typedef struct {
+    uint32_t cs;
+    uint32_t conblk_ad;
+    uint32_t ti;
+    uint32_t source_ad;
+    uint32_t dest_ad;
+    uint32_t txfr_len;
+    uint32_t stride;
+    uint32_t nextconbk;
+    uint32_t debug;
+
+    qemu_irq irq;
+} BCM2835DMAChan;
+
+#define TYPE_BCM2835_DMA "bcm2835-dma"
+#define BCM2835_DMA(obj) \
+        OBJECT_CHECK(BCM2835DMAState, (obj), TYPE_BCM2835_DMA)
+
+#define BCM2835_DMA_NCHANS 16
+
+typedef struct {
+    /*< private >*/
+    SysBusDevice busdev;
+    /*< public >*/
+
+    MemoryRegion iomem0, iomem15;
+    MemoryRegion *dma_mr;
+    AddressSpace dma_as;
+
+    BCM2835DMAChan chan[BCM2835_DMA_NCHANS];
+    uint32_t int_status;
+    uint32_t enable;
+} BCM2835DMAState;
+
+#endif