SSP bus framework

Signed-off-by: Paul Brook <paul@codesourcery.com>

1 files changed, 41 insertions, 0 deletions

diff --git a/hw/ssi.h b/hw/ssi.h
new file mode 100644
index 0000000..d9865e6
--- /dev/null
+++ b/hw/ssi.h
@@ -0,0 +1,41 @@
+/* QEMU Synchronous Serial Interface support.  */
+
+/* In principle SSI is a point-point interface.  As such the qemu
+   implementation has a single slave device on a "bus".
+   However it is fairly common for boards to have multiple slaves
+   connected to a single master, and select devices with an external
+   chip select.  This is implemented in qemu by having an explicit mux device.
+   It is assumed that master and slave are both using the same transfer width.
+   */
+
+#ifndef QEMU_SSI_H
+#define QEMU_SSI_H
+
+#include "qdev.h"
+
+typedef struct SSISlave SSISlave;
+
+/* Slave devices.  */
+typedef struct {
+    void (*init)(SSISlave *dev);
+    uint32_t (*transfer)(SSISlave *dev, uint32_t val);
+} SSISlaveInfo;
+
+struct SSISlave {
+    DeviceState qdev;
+    SSISlaveInfo *info;
+};
+
+#define SSI_SLAVE_FROM_QDEV(dev) DO_UPCAST(SSISlave, qdev, dev)
+#define FROM_SSI_SLAVE(type, dev) DO_UPCAST(type, ssidev, dev)
+
+void ssi_register_slave(const char *name, int size, SSISlaveInfo *info);
+
+DeviceState *ssi_create_slave(SSIBus *bus, const char *name);
+
+/* Master interface.  */
+SSIBus *ssi_create_bus(void);
+
+uint32_t ssi_transfer(SSIBus *bus, uint32_t val);
+
+#endif