diff options
Diffstat (limited to 'qemu/include/hw/ssi.h')
-rw-r--r-- | qemu/include/hw/ssi.h | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/qemu/include/hw/ssi.h b/qemu/include/hw/ssi.h new file mode 100644 index 000000000..df0f83851 --- /dev/null +++ b/qemu/include/hw/ssi.h @@ -0,0 +1,94 @@ +/* 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 |