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-rw-r--r--src/include/hw/ssi.h94
1 files changed, 94 insertions, 0 deletions
diff --git a/src/include/hw/ssi.h b/src/include/hw/ssi.h
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+/* 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 "hw/qdev.h"
+
+typedef struct SSISlave SSISlave;
+
+#define TYPE_SSI_SLAVE "ssi-slave"
+#define SSI_SLAVE(obj) \
+ OBJECT_CHECK(SSISlave, (obj), TYPE_SSI_SLAVE)
+#define SSI_SLAVE_CLASS(klass) \
+ OBJECT_CLASS_CHECK(SSISlaveClass, (klass), TYPE_SSI_SLAVE)
+#define SSI_SLAVE_GET_CLASS(obj) \
+ OBJECT_GET_CLASS(SSISlaveClass, (obj), TYPE_SSI_SLAVE)
+
+#define SSI_GPIO_CS "ssi-gpio-cs"
+
+typedef enum {
+ SSI_CS_NONE = 0,
+ SSI_CS_LOW,
+ SSI_CS_HIGH,
+} SSICSMode;
+
+/* Slave devices. */
+typedef struct SSISlaveClass {
+ DeviceClass parent_class;
+
+ int (*init)(SSISlave *dev);
+
+ /* if you have standard or no CS behaviour, just override transfer.
+ * This is called when the device cs is active (true by default).
+ */
+ uint32_t (*transfer)(SSISlave *dev, uint32_t val);
+ /* called when the CS line changes. Optional, devices only need to implement
+ * this if they have side effects associated with the cs line (beyond
+ * tristating the txrx lines).
+ */
+ int (*set_cs)(SSISlave *dev, bool select);
+ /* define whether or not CS exists and is active low/high */
+ SSICSMode cs_polarity;
+
+ /* if you have non-standard CS behaviour override this to take control
+ * of the CS behaviour at the device level. transfer, set_cs, and
+ * cs_polarity are unused if this is overwritten. Transfer_raw will
+ * always be called for the device for every txrx access to the parent bus
+ */
+ uint32_t (*transfer_raw)(SSISlave *dev, uint32_t val);
+} SSISlaveClass;
+
+struct SSISlave {
+ DeviceState parent_obj;
+
+ /* Chip select state */
+ bool cs;
+};
+
+#define FROM_SSI_SLAVE(type, dev) DO_UPCAST(type, ssidev, dev)
+
+extern const VMStateDescription vmstate_ssi_slave;
+
+#define VMSTATE_SSI_SLAVE(_field, _state) { \
+ .name = (stringify(_field)), \
+ .size = sizeof(SSISlave), \
+ .vmsd = &vmstate_ssi_slave, \
+ .flags = VMS_STRUCT, \
+ .offset = vmstate_offset_value(_state, _field, SSISlave), \
+}
+
+DeviceState *ssi_create_slave(SSIBus *bus, const char *name);
+DeviceState *ssi_create_slave_no_init(SSIBus *bus, const char *name);
+
+/* Master interface. */
+SSIBus *ssi_create_bus(DeviceState *parent, const char *name);
+
+uint32_t ssi_transfer(SSIBus *bus, uint32_t val);
+
+/* Automatically connect all children nodes a spi controller as slaves */
+void ssi_auto_connect_slaves(DeviceState *parent, qemu_irq *cs_lines,
+ SSIBus *bus);
+
+/* max111x.c */
+void max111x_set_input(DeviceState *dev, int line, uint8_t value);
+
+#endif
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