2 * QEMU I2C bus interface.
4 * Copyright (c) 2007 CodeSourcery.
5 * Written by Paul Brook
7 * This code is licenced under the LGPL.
14 i2c_slave
*current_dev
;
19 static void i2c_bus_save(QEMUFile
*f
, void *opaque
)
21 i2c_bus
*bus
= (i2c_bus
*)opaque
;
23 qemu_put_byte(f
, bus
->current_dev
? bus
->current_dev
->address
: -1);
26 static int i2c_bus_load(QEMUFile
*f
, void *opaque
, int version_id
)
28 i2c_bus
*bus
= (i2c_bus
*)opaque
;
33 /* The bus is loaded before attached devices, so load and save the
34 current device id. Devices will check themselves as loaded. */
35 bus
->saved_address
= (int8_t) qemu_get_byte(f
);
36 bus
->current_dev
= NULL
;
41 /* Create a new I2C bus. */
42 i2c_bus
*i2c_init_bus(void)
46 bus
= (i2c_bus
*)qemu_mallocz(sizeof(i2c_bus
));
47 register_savevm("i2c_bus", -1, 1, i2c_bus_save
, i2c_bus_load
, bus
);
51 void i2c_set_slave_address(i2c_slave
*dev
, int address
)
53 dev
->address
= address
;
56 /* Return nonzero if bus is busy. */
57 int i2c_bus_busy(i2c_bus
*bus
)
59 return bus
->current_dev
!= NULL
;
62 /* Returns non-zero if the address is not valid. */
63 /* TODO: Make this handle multiple masters. */
64 int i2c_start_transfer(i2c_bus
*bus
, int address
, int recv
)
68 for (dev
= bus
->dev
; dev
; dev
= dev
->next
) {
69 if (dev
->address
== address
)
76 /* If the bus is already busy, assume this is a repeated
78 bus
->current_dev
= dev
;
79 dev
->info
->event(dev
, recv
? I2C_START_RECV
: I2C_START_SEND
);
83 void i2c_end_transfer(i2c_bus
*bus
)
85 i2c_slave
*dev
= bus
->current_dev
;
90 dev
->info
->event(dev
, I2C_FINISH
);
92 bus
->current_dev
= NULL
;
95 int i2c_send(i2c_bus
*bus
, uint8_t data
)
97 i2c_slave
*dev
= bus
->current_dev
;
102 return dev
->info
->send(dev
, data
);
105 int i2c_recv(i2c_bus
*bus
)
107 i2c_slave
*dev
= bus
->current_dev
;
112 return dev
->info
->recv(dev
);
115 void i2c_nack(i2c_bus
*bus
)
117 i2c_slave
*dev
= bus
->current_dev
;
122 dev
->info
->event(dev
, I2C_NACK
);
125 void i2c_slave_save(QEMUFile
*f
, i2c_slave
*dev
)
127 qemu_put_byte(f
, dev
->address
);
130 void i2c_slave_load(QEMUFile
*f
, i2c_slave
*dev
)
133 bus
= qdev_get_bus(&dev
->qdev
);
134 dev
->address
= qemu_get_byte(f
);
135 if (bus
->saved_address
== dev
->address
) {
136 bus
->current_dev
= dev
;
140 static void i2c_slave_qdev_init(DeviceState
*dev
, void *opaque
)
142 I2CSlaveInfo
*info
= opaque
;
143 i2c_slave
*s
= I2C_SLAVE_FROM_QDEV(dev
);
146 s
->bus
= qdev_get_bus(dev
);
147 s
->address
= qdev_get_prop_int(dev
, "address", 0);
148 s
->next
= s
->bus
->dev
;
154 void i2c_register_slave(const char *name
, int size
, I2CSlaveInfo
*info
)
156 assert(size
>= sizeof(i2c_slave
));
157 qdev_register(name
, size
, i2c_slave_qdev_init
, info
);
160 DeviceState
*i2c_create_slave(i2c_bus
*bus
, const char *name
, int addr
)
164 dev
= qdev_create(bus
, name
);
165 qdev_set_prop_int(dev
, "address", addr
);