| /* 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-core.h" |
| |
| typedef struct SSISlave SSISlave; |
| typedef struct SSISlaveClass SSISlaveClass; |
| typedef enum SSICSMode SSICSMode; |
| |
| #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" |
| |
| enum SSICSMode { |
| SSI_CS_NONE = 0, |
| SSI_CS_LOW, |
| SSI_CS_HIGH, |
| }; |
| |
| /* Slave devices. */ |
| struct SSISlaveClass { |
| DeviceClass parent_class; |
| |
| void (*realize)(SSISlave *dev, Error **errp); |
| |
| /* 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); |
| }; |
| |
| 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 |